ArticlePDF Available

Chemico-nanotreatment methods for the removal of persistent organic pollutants and xenobiotics in water -A review

January 2021

January 2021

Authors:

Karthigadevi Guruviah

Sri Venkateshwara College Of Engineering

Subbaiya Ramasamy

The Copperbelt University

Chozhavendhan Sivasankaran

Vivekanandha College of Engineering for Women

Ravindran Balasubramani

Southkorea

Show all 6 authorsHide

Types of nanocomposites in pollutant degradation.

…

Advances and limitations of adopting nano-treatment approaches in POPs and xenobiotic removal.

…

Various treatment methods employed for xenobiotic degradation.

…

Photocatalytic degradation for treatment of wastes using nano-composites.

…

Figures - uploaded by Chozhavendhan Sivasankaran

Content may be subject to copyright.

Content uploaded by Chozhavendhan Sivasankaran

Content may be subject to copyright.

Bioresource Technology 324 (2021) 124678

Available online 7 January 2021

Review

Chemico-nanotreatment methods for the removal of persistent organic

pollutants and xenobiotics in water – A review

Guruviah Karthigadevi

, Sivasubramanian Manikandan

, Natchimuthu Karmegam

Ramasamy Subbaiya

, Sivasankaran Chozhavendhan

, Balasubramani Ravindran

Soon Woong Chang

, Mukesh Kumar Awasthi

College of Natural Resources and Environment, Northwest A&F University, Taicheng Road 3#, Yangling, Shaanxi 712100, China

Department of Biotechnology, Sri Venkateswara College of Engineering, (Autonomous), Sriperumbudur TK - 602 117, Tamil Nadu, India

Department of Biotechnology, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha Nagar, Thandalam, Chennai -

602 105, Tamil Nadu, India

Department of Botany, Government Arts College (Autonomous), Salem - 636 007, Tamil Nadu, India

Department of Biological Sciences, School of Mathematics and Natural Sciences, The Copperbelt University, Riverside, Jambo Drive, P.O. Box. 21692, Kitwe, Zambia

Department of Biotechnology, V.S.B Engineering College, Karur – 639 111, Tamil Nadu, India

Department of Environmental Energy and Engineering, Kyonggi University, Youngtong-Gu, Suwon, 16227, South Korea

HIGHLIGHTS GRAPHICAL ABSTRACT

•Persistent and xenobiotic compounds

pollution in water sources affect

environment.

•Chemical treatments for xenobiotics

removal are practicable and costly.

•Nanotechnology provides low-cost

nanomaterials for wastewater

treatments.

•Nanomaterials are excellent agents for

eliminating xenobiotics in wastewater.

ARTICLE INFO

Keywords:

Nanomaterials

Persistent pollutants

Photocatalysis

Wastewater treatment

Xenobiotics

ABSTRACT

While the technologies available today can generate high-quality water from wastewater, the majority of the

wastewater treatment plants are not intended to eliminate emerging xenobiotic pollutants, pharmaceutical and

personal care items. Most endocrine disrupting compounds (EDCs) and personal care products (PPCPs) are more

arctic than most regulated pollutants, and several of them have acid or critical functional groups. Together with

the trace occurrence, EDCs and PPCPs create specic challenges for removal and subsequent improvements of

wastewater treatment plants. Various technologies have been investigated extensively because they are highly

persistent which leads to bioaccumulation. Researchers are increasingly addressing the human health hazards of

xenobiotics and their removal. The emphasis of this review was on the promising methods available, especially

nanotechnology, for the treatment of xenobiotic compounds that are accidentally released into the setting. In

* Corresponding author at: College of Natural Resources and Environment, Northwest A&F University, Taicheng Road 3#, Yangling, Shaanxi 712100, China.

E-mail address: mukesh_awasthi45@yahoo.com (M.K. Awasthi).

Contents lists available at ScienceDirect

Bioresource Technology

journal homepage: www.elsevier.com/locate/biortech

https://doi.org/10.1016/j.biortech.2021.124678

Received 3 December 2020; Received in revised form 29 December 2020; Accepted 2 January 2021

Bioresource Technology 324 (2021) 124678

terms of xenobiotic elimination, nanotechnology provides better treatment than chemical treatments and their

degradation mechanisms are addressed.

1. Introduction

Owing to the widespread event of persistent organic contaminants

and xenobiotics, knowledge of their occurrence in the environment is

very critical in the past decades. Under the Stockholm Convention 21

organic persistent contaminants with high toxicological risk have been

reported (des Ligneris et al., 2018). The main purpose of the Convention

of Stockholm is to nd the right way of preventing pollutant accumu-

lation and to identify new persistent organic pollutants (POPs). Re-

searchers focus more on cleaning xenobiotics and POPs from

environmental media using different technologies (Pi et al., 2018). The

fact that most POPs and xenobiotics are accumulated in surface water

and drinking water as micropollutant substances present many chal-

lenges to quantication and detection. Recently, EU guidelines have laid

down regulations to periodically track releases of xenobiotics to mini-

mize this step in a wise manner (Sousa et al., 2018). Some pesticides and

pharmaceutical products have been reviewed and updated by the reg-

ulatory authorities based on priority setting. The study shows the pre-

dominance of pesticides and drugs among the xenobiotic compounds

and that their removal is a major concern because of their low degrad-

ability (Liu et al., 2020). On the global stage, the distribution of organic

xenobiotics primarily affects agro and aquatic environments, and so

treatment processes for developing countries are the prerequisites.

Conventional wastewater treatment methods for xenobiotic removal

were initially employed but due to its hydrophilic existence, the efu-

ents were released in a merging environment. Many techniques have

been developed over the decades, such as advanced oxidation, electro-

chemical and photochemical processes (Chakraborty et al., 2020; Lin

and Lee, 2010), but they do not eliminate organic pollutants. To mitigate

or remove releases to the atmosphere, POPs are dened as being based

on reduction, output and accidental production (Stockholm conven-

tion). According to geographical locations, these compounds continue to

inuence the climate, people and animals (Tran et al., 2018). Both soil

and human species expose these compounds to a variety of causes of

disease such as metabolic disorders, kidney injury, insomnia and ner-

vous disorders (George et al., 2017; Garza-Lomb´

o et al., 2018). For the

treatment of POPs and xenobiotics in the earlier decades, chemical

processes such as reduction, oxidation, precipitation, ion exchangers

and adsorption have been used. These are not cost-efcient approaches,

however, and require non-environmentally friendly procedures to

establish environmental sustainability problems (Ramírez-García et al.,

2019).

In recent days, there has been a surge to resolve the problem; sci-

entists are making technological advances to optimize the method of

pollutant cleaning at ‘0’ levels. Several literature pieces focused upon

safe practices through the use of natural materials, and nano-

technological approaches to extract heavy metals and dyes from

wastewater (Le et al., 2015). Nanomaterials have outstanding properties

because they are capable of transforming their structures into specic

functionalities, which display greater promise in wastewater treatment.

A wide variety of nanomaterials have been tested as reliable, cost-

effective and environmentally safe for the treatment of industrial ef-

uents, soil waters, surface water and drinking water (Kodama et al.,

2015; Pang et al., 2011). Based on the literature research, scientists

make efforts to develop new materials by combining technical innova-

tion with human ecological risk evaluations. Nanotechnology that is

effectively used to disposing of contaminants allows such materials

possible. The current review summarises the multidisciplinary ap-

proaches involved in the design, manufacture, transport and removal of

xenobiotics and the environmental risks associated with them.

1.1. Sources of xenobiotics and POPs

Xenobiotics are diversied manmade chemicals released into the

environment each of which has the potential ability to cause an envi-

ronmental hazard and the dose level may be either higher for one

compound compared to others. The inherent properties of xenobiotics

are different and pollutant nature is expelled from each source. Certain

sources of xenobiotics may release a single deleterious compound or it

could be a mixture of organic pollutants. A single pollutant or combi-

nation of pollutant compounds can be used in xenobiotics, rendering

environmental protection – a major activity. Based on the characteristics

of xenobiotics, natural or anthropogenic releases have been categorized

as deliberate or accidental, direct, or indirect releases. Most xenobiotics

are released as volatilized contaminants that are collected in the air from

industries, which spread directly to soil surfaces, and then released into

aquatic areas by precipitation. The origin of xenobiotics must be clas-

sied so that harmful contaminants can be restricted. The sum of re-

leases from a given location should be calculated under the Stockholm

Convention 2009 so that we can quantify the transport potential.

POPs are halogenated xenobiotic compounds to which human beings

are largely exposed through various commodities either through point

or nonpoint sources. These contaminants are extremely toxic com-

pounds in the atmosphere that are highly bio-accumulative and can

disrupt the food supply chain of the microbiome. Under the guidelines of

the Environmental Protection Agency (EPA), the incidence rates of

diseases caused by these contaminants in the marine and coastal eco-

systems are high. People who have now adapted themselves to modern

lifestyles using the articial compounds are purposely released into the

world’s atmosphere. POPs are categorized under 4 levels: (i) the most

dangerous chemicals which are under restriction for production and use,

(ii) the medium level chemicals which are restricted to use in the pro-

duction process, (iii) the discharge of chemicals unintentionally during

the production process, and (iv) the use of chemicals under investiga-

tion. The required steps for pollution control will be taken in the sites,

based on the screening results done by various communities’ interna-

tional levels. Normal surveillance to estimate the parameters was co-

ordinated, and campaigns were arranged to slacken the production, use

and release of POPs as they are highly persistent in the environment as a

non-degradable pollutant (Daley et al., 2014). These pollutants undergo

bioaccumulation by the organisms which result in changes in toxicity

levels or it disturbs the metabolism of the microbes.

1.2. Ecological risks associated with xenobiotics and POPs

Xenobiotics released from the various industries and agricultural

activities have now become a global issue as it creates a greater impact

on the ecosystem. There has been an outbreak of several diseases that

occurs to the food-producing animals in connection with this contami-

nant release which in turn affects the health of the humans. This mainly

occurs due to the use of organo-chlorinated pesticides which have been

used over years in agricultural elds (Qi et al., 2020). Such compounds

will not be removed completely from the soil and also the use of recy-

cling wastewater containing POPs gets adsorbed into the soil. It affects

the soil microbial populations which lead to the damage of the plant

thereby affecting the symbiotic relationship between plant and micro-

organisms (Meena et al., 2020). So the roles of microbial biosynthetic

mechanisms are altered so the remediation of the pollutants will also get

disturbed completely resulted in poor degradation. It also imbalances

the soil fertility which affects the yield of crops.

Ecological risk data assessment of POPs showed that the adsorption

of compounds will be higher in low-temperature regions. Because POPs

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

migrate to the high latitude atmospheres remains to settle in the air and

there is a possibility to transfer to the marine environments. So the

marine areas in polar-regions have high accumulation when compared

to other regions (Zhang et al., 2018). Hence the people who live in these

regions are at greater risk of bioaccumulation of these components as

they depend highly on seafood (Song et al., 2019a). Generally, exposure

to xenobiotic compounds is a continuous action nowadays via food,

water and commercial products as they always pose serious risks to the

living system (Diamanti-Kandarakis et al., 2009). The level of risk varies

according to the type of chemical, their toxicity nature and their inter-

action with the living organisms. The impact of risk on ecology depends

on the genetic factors of the consumers and also based on how long they

are exposed to the particular chemical and their dose levels. The

assessment of risk should be done based on the quantication of indi-

vidual chemicals present in the group of components present in the

mixture which is the major issue due to the bioavailability nature of the

microorganism for the xenobiotic compounds. Based upon the specic

type of the microorganisms, the adsorption, degradation and meta-

bolism of the xenobiotic compounds also vary which leads to compli-

cations in the removal. So the identication of reliable risk assessment

procedures should be done to balance the environmental protection at a

minimal cost.

1.3. POPs and their interrelations with human health

Nowadays, most of the xenobiotic compounds are used in drugs,

cosmetics and agriculture produce inimical effects to the consumers.

There is an inevitable exposure to a variety of chemicals, there is a need

to focus on the evaluation of possible toxicological effects on humans

and animals has to be focussed. As the variation in the composition of

xenobiotic compounds, the effect may be genotoxic, immuno-toxic,

nephrotoxic, neurotoxic and hepatotoxic, the Stockholm Convention

identied 12 major offenders of pesticide residues, synthetic chemicals

and accidental by-products. The Convention took crucial measures to

protect human health and the environment by removing POPs and

eliminating their production and trade. As the POPs persist on lower

doses in the atmosphere, but in the live organisms, they can bio-

accumulate. These can interact through the mouth, inhalation, and

dermal with living systems, but the impacts of those POPs are not

entirely understood. No major health disorders are caused by a limited

amount of exhibition. Continuous exposure to specic chemicals has

recently been exacerbated as many have resulted in developmental

disorders, reproductive defects, cancer and teratogenic effects, animal

and human endocrine disruptors (Sharma et al., 2014) which is sche-

matically explained in Fig. 1.

In recent years, humans who have been exposed to larger quantities

of polystyrene compounds contain minute particles that may translocate

into the human system and have an effect on the population of the im-

mune cells (Wang et al., 2021). The government has made efforts to

minimize the rate of MOPs and regulated risk margins relative to pre-

vious decades. The lethal effects of each organic matter should be

studied because single organic pollutants can cause no effects but a

combination of organic pollutants causes adverse effects. As each POP

has a particular health inuence, exposure to a variety of POPs has

Fig. 1. ADME impact of xenobiotics on human system.

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

negative and epidemic; animal research studies are showing harmful

effects on the health of living things. Therefore, various methods of

treatment are required to protect individuals from harmful health con-

ditions such as learning disabilities, birth defects and behavioral defects.

Additionally, the intake of food from such xenobiotic polluted soils gets

accumulated in the human adipose tissues which induce obsogenesis

and also interrupt the metabolism of the human systems (La Merrill

et al., 2013). From the epidemiological studies, it is inferred that even

low-dose POPs have been linked with chronic metabolic disorders (Zhou

et al., 2020).

1.4. Control and removal measures of POPs

Remediation methods are required for the removal of POPs so that

knowledge about the chemical properties of POPs can be obtained.

Several approaches to battle the effects of POPs are available and their

development and application are minimized. The US Government has

adopted legislation banning the use of POPs using many conventions.

The Agency for Environmental Protection has made serious efforts to

avoid its release into earth, air and water that decreased nearly 90% of

its releases. As a result, physical, chemical and biological remediation

technologies are being developed (Deng and Tam, 2015). Naturally,

bioremediation processes are carried out in soil using existing environ-

mental microorganisms, but they do not eliminate POPs. Genetic engi-

neering technologies help us improving the capacity of microorganisms

to clean up contaminants (Khan et al., 2016). Several researchers have

shown that bioaugmentation and methods of phytoremediation have

been utilized in a viable manner to rehabilitate polycyclic aromatic

hydrocarbons and many contaminants (Egorova et al., 2017). These

methods are subjected to limitations because of microbial contamina-

tion. The emerging technologies are focused on the elimination of con-

taminants but these have proven to be effective for trace quantities in

the removal. To deal with the removal of high-dose pollutant problems,

the integration of techniques has to be made to nd a possible outcome

(Navaratna et al., 2016). In this study, the techniques of removing

xenobiotic compounds that have accumulated as persistent contami-

nants in the atmosphere in recent decades have been discussed (Table 1).

2. Treatment methods for degradation of POPs and xenobiotics

Around ten million xenobiotic chemicals are released into the

aquatic environment by the factories, containing a large number of

different xenobiotic compounds interacting due to their physical and

chemical properties. There are approximately 129 pollutants screened

by the US Clean Water Act (MERL, USA EPA) under special re-

quirements, which includes heavy metals and organic chemical

products. To degrade the xenobiotic in the water, physical and chemical

methods have been developed over the years, but are unable to elimi-

nate persistent organic contamination. Modern techniques for dening

and quantifying substances based on their molecular dimension, the

solubility of water, polarity and volatility provide major solutions for

extracting POPs from the setting (Megson et al., 2016). Potential ana-

lytic treatment methods for the detection of complex compounds, even

when stored in minimum concentrations, are on the boom. Bio-

treatment approaches arose as an alternative low-cost technology for

high ecological dominance wastewater treatment (Delforno et al.,

2015). In particular, aerobic microorganisms use xenobiotics as a source

of their carbon since they are catabolic, resulting in either degradation

or transformation of the compounds. These remediation approaches can

cause the degradation of most simple organic pollutants, but for decades

the environment has received POPs, such as polyhydroxyalkanoate,

polychlorinated biphenyls, DDT and heterocyclic compounds, as well as

organophosphorus pesticides because of their high biomagnication and

bioaccumulation (Donyinah, 2019). Since chemical concentration

excessively exceeds, microorganisms cannot efciently handle efuents,

and new technologies, such as chemical oxidation methods and nano

treatment methods, are evolving, thereby decreasing toxicity, followed

by biological treatments, to lower levels (Table 2).

2.1. Chemical treatment methods in wastewater treatment

2.1.1. Coagulation–occulation for the removal of xenobiotics

Coagulation is typically used for the elimination of xenobiotic com-

pounds by the process of sedimentation and ltration, based on mass

transition, in water treatments. The neutralization of charged particles is

involved in a gelatinous mass, which is ltered by the application of an

agitation process to turn the colloidal particles into occulation and

separated from the solution by the occulation method (Pariatamby and

Kee, 2016). The option of chemical methods is based on compound form,

chemical structure and other organic ingredients. In this process the

removal of inorganic metal compounds and hazardous sludge compo-

nents is difcult. The treatment of contaminants with inorganic co-

agulants is not easy to scaling, replacing natural coagulants. The

efciency of POPs and xenobiotics removal in the coagulation and

occulating processes is determined by the velocity gradient, time, pH,

temperature and retention time. This technology is effectively used to

treat phthalic acid esters, petroleum hydrocarbons and halogenated

compounds (Nascimento et al., 2019). The electro-coagulation method

has been used to remove the endocrine-disrupting chemicals by using

amorphous aluminum oxide as a coagulating agent. Sweep occulation

mechanism promotes the rapid absorption of the soluble organic con-

taminants on the surface of the ocs and it is followed by ltration

Table 1

Various treatment methods employed for xenobiotic degradation.

Method of xenobiotic

treatment

Technologies used Advantages Disadvantages References

Physical methods Membrane ltration

Natural zeolite

Adsorption

Less solid wastes

Less use of hazardous

chemicals

Removal efciency is less

High investment and running

cost

(Asif et al., 2018)

(Kadam et al., 2019)

(Luo et al., 2018)

Chemical methods Chemical precipitation

Chemical coagulation

Electrochemical methods

Simple

High regeneration capacity

Highly selective

Chemical consumption is high

High capital cost

(Abdullah et al., 2020)

(Chen et al., 2020)

Biological methods Phytoremediation

Bioaugmentation

Phytovolatilization

Phytoaccumulation

Rhizodegradation

Bioremediation

phytodegradation

Energy expenditure is low

Environmental friendly

Cost/benet ratio is low (Chen et al., 2011)

(Jung and Ahn, 2016)

(Leong and Chang, 2020)

(Yu et al., 2020)

Nano treatment methods Adsorption and photocatalytic

degradation

High removal capability

High regeneration efciency

Scale-up is difcult (Moharrami and Motamedi,

2020)

(Xiang et al., 2020)

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

mechanisms (Cook et al., 2016).

2.1.2. Chemical precipitation method for the removal of xenobiotics

Xenobiotics contained in the personal care products largely contains

a class of emerging contaminants that include synthetic hormones,

parabens, surfactants and antimicrobials. Almost 70% of such contam-

inants showed poor removal efciencies, this has to be treated using

counter ion compounds (Biel-Maeso et al., 2019). Chemical precipita-

tion works primarily by modifying the chemical components of such

POPs to minimize the solubility of these compounds. This can be ach-

ieved by the addition of counter-ions to remove the ionic components

from the solution to precipitate the suspended solids (Pohl, 2020). This

process is used primarily for the treatment of industrial wastewater

containing organic contaminants like phenols or aromatic amines. By

adjusting the pH of a mixture with a high degree of selectivity it is also

possible to isolate heavy metals using this process. The downside is that

reagents are used to adjust the solubility of by-products which ensures

that the production costs are high to satisfy pure requirements.

2.1.3. Ammonium stripping method for the removal of xenobiotics

Ammonium stripping is used for the disposal of the recalcitrant

heavy metals and hydrocarbon that accumulate in particular in the form

of waste dumps. In contrast with other forms of treatment, this stripping

effectively extracts NH

-N-compounds with low operating costs. The

removal of ammonia-based nitrogen can be achieved via the separation

process for sludge dewatering. Change of pH, temperature, time, volu-

metric load, reactor conguration and air-liquid ratio can optimize

process magnitude (Kinidi et al., 2018). The major limitation of this

process is the release in the atmosphere of ammonia, which causes a

considerable effect on the environment.

2.1.4. Advanced oxidation method for the removal of xenobiotics

Advanced oxidation process (AOP) mainly involves the use of oxi-

dants to degrade organic pollutants that emit reactive oxygen species

(ROS) is needed. This approach refers to contaminants in the soil and

sediments in the water (Cuerda-correa et al., 2020). The degradation

process comprises 4 stages: (i) hydrogen abstraction, (ii) the addition of

free radicals, (iii) the combination of free radicals and molecules, and

(iv) electron transfer (Badmus et al., 2018). Most volatile organic

compounds such as PCBs, Dioxins and PHA are eliminated from the

production of free radicals by advanced oxidation methods. For

example, the electrochemical peroxidation technique uses electricity for

the generation of free radicals. It is an integrated AOP technique that

includes the Fenton, photocatalytic processes along with biological

treatment methods which can, in some respect, eliminate non-

biodegradable contaminants present in the synthetic wastewater (Mor-

eira et al., 2017). Earlier the recalcitrant xenobiotics are removed by

using hydroxyl radical based advanced oxidation process. Now the

recent researchers used sulfate radicals for the removal of ammonia

nitrogen in the wastewater even if it is in traceable amounts (Deng and

Zhao, 2015). Particularly, this AOP is a viable option for the treatment of

landll leachate and efuent organic matters. Radical oxidation of sul-

fate even in the treatment of AOPs is possible apart from this hydroxyl

radical oxidation. The hydroxyl radical dramatically controlled AOP is

used to eliminate inorganic contaminants and recalcitrant organic

matter. The sulfate radical-mediated AOP, which is not effectively

Table 2

Various types of xenobiotics, their impact on environment and degradation mechanisms.

Source of

xenobiotics

Xenobiotics type Xenobiotic

applications

Xenobiotic compound Impact on the soil and

water

Degradation mechanism References

Industrial wastes Chemical

Industries

Plasticizers Phthalate esters di-(2-ethylhexyl)

phthalate (DEHP) and di-n-octyl

phthalate (DOP), dimethyl phthalate

(DMP), diethyl phthalate (DEP), and

dibutyl phthalate (DBP)

i. Genetic aberrations

to the marine

animals

ii. Reproductive

defects in sh

Photocatalytic

degradation

(Pang et al.,

2021)

Textile Industries Acid dyes

Basic dyes

Mordants

Pigments

Additives

Direct Blue 6 Direct Black 38

Azo dyes

Pthaleine dyes

Indigo dyes

Anthraquinone dyes

Nitrosodyes

Synthetic dyes

i. Water contamination Electrochemical

degradation

Biodegradation

(Siddique

et al., 2011)

Pesticide wastes Pesticide

Industries

Pesticide

Herbicide

Insecticide

Organophosphate and organo-chlorine

compounds

Chlorinated hydrocarbons

i. Affect soil microbes

ii. Ground water

pollution

iii. Damage to

successive crop

generations

Microbial degradation (Kumar

et al., 2018)

Pharmaceutical

wastes

Pharmaceutical

industries

Analgesics Ibuprofen,

Paracetamol

i. Surface water

contamination

ii. Risk to aquatic

microbiome

Ozone oxidation

Coagulation

–occulatiom

Membrane separation

(˙

Zur et al.,

2018)

Antibiotics Ampicillin, Ciprooxacin, Gatioxacin,

Sparoxacin, and Cepuroxime

i. Eutrophication

ii. Damage to the

microbial diversity

Biotransformation

Bioremediation

(Sharma

et al., 2017)

Anti convulsants Carbamazepine, Phenytoin

Valproic acid, lacosamide, lamotrigine,

oxcarbazepine, topiramate, and

zonisamide.

i. Toxic effects on

earthworms

UV photo-oxidation (Litskas

et al., 2019)

(Silva et al.,

2018)

Cosmetic wastes Personal care

products

Nail polish,

deodorants,

shampoos,

toothpaste, shower

gels

UV lters

Phthalates, triclosan, Parabens,

ethyleneoxide, 1,3 butadiene

i. Bioaccumulation

ii. Teratogenic effects

Carbocatalytic oxidation

and hydrothermal (HT)

hydrolysis

(Kang et al.,

2019)

Food processing

wastes

Food processing

industries

Genotoxins

cytotoxins

nitrosamines (NA), heterocyclic amines

(HCAs), and polycyclic aromatic

hydrocarbons (PAHs)

i. Surface water

contamination

ii. Methane generation

due to landlling

Anaerobic and aerobic

digestion

Bioremediation

(Nogacka

et al., 2019)

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

eliminated by the hydroxyl radical-mediated AOP, readily oxidizes

ammonia and nitrogen compounds (Guerra-Rodríguez et al., 2018). The

efciency of the treatment process was dependent on the physical-

chemical properties and operating parameters of organic pollutants.

Many other AOPs for recalcitrant waste treatment have been added,

such as ultrasound-mediated, electronic radiation beam-dependent

AOPs, ozone-dependent AOPs which are based on the 3-phase method

of hydrodynamic cavitations (nucleation, growth and collapse) methods

(Camargo-Perea et al., 2020; Giwa et al., 2021).

2.2. Nano treatment methods in the removal of xenobiotics and POPs

In recent years, the emergence of pollutants in the water environ-

ments are accelerated which possess greater risks to life. As the con-

ventional treatment methods do not effectively remove the pollutants

which are in minor dose levels, the nanomaterials with signicant

physicochemical properties offer a way to rule out all those limitations

(Cai et al., 2018). Various techniques such as adsorption (Manikandan

et al., 2021), photocatalytic degradation (Zhang et al., 2020a, 2020b),

membrane ltration (Chen et al., 2018) and ozonation phenomenon

(Song et al., 2019a, 2019b; Chen et al., 2021) have been explored by the

researchers for the application of engineered nanoparticles and their

specicity in the treatment of such pollutants. The design of various

novel nanomaterials using a variety of sources for the degradation of

pollutants and their mechanisms of reactions have been piled up. As the

nanomaterials possess inherent physiochemical and magnetic proper-

ties, the selection of the nanomaterial should be done accordingly to trap

the specic pollutant. The combination of nanomaterials with either

plant or microorganisms is also effectively involved in the trans-

formation of pollutants to achieve complete elimination from the

ecosystem.

2.2.1. Adsorption method for removal of xenobiotics

Activated carbon has microporous structures that aid in the ef-

ciency of the adsorption process in removing POPs (Pandiarajan et al.,

2018). The diffusion mechanism of the process and the activated carbon

decreases the soil’s pollutant sorption rate. The surface load density

varies depending on the material type and the electrostatic reaction of

the CA with the contaminant paves the way for the removal. This

approach effectively eliminates wastes based on optimizing pH as an

essential factor in the adsorption of toxins, phenol and trichlorophenol.

Due to its removal efciency, there is an increase in demand for this

technology, but the key limit is the cost incurred for the adsorption

process. So there is a need to nd alternative sources that possess better

adsorption as well as for the regeneration of components. This has been

done by integrating the surface phenomenon with the bioremediation

techniques to remove the aromatic hydrocarbons in the saline waste-

water (Gonz´

alez-Abradelo et al., 2019; Zhang et al., 2020a).

Pharmaceutical-based xenobiotic compounds are usually non-

degradable due to their high solubility nature. In such a case, the

adsorption process remains an effective option due to its process char-

acteristics. Now, the biosorbents are in trend for the treatment of

pharmaceutically active compounds due to their ability to remove the

contaminants completely without releasing any byproducts. Also, the

sorption process is economically feasible due to its high regeneration

capacity as well as its aids in bioaccumulation and biomagnication of

the wastes (Adewuyi, 2020).

2.2.2. Photocatalytic degradation for removal of xenobiotics

Photocatalysis includes primarily the use of irradiation to produce

photo charges that pass effectively to any surface and cause organic

contaminants to be mineralized (Qin et al., 2020). Due to their low cost,

chemical stability, and structure-dependent electronic properties,

several different semi-conductive materials are used as a photocatalyst

(Kar et al., 2020). To boost the degradation properties of such semi-

conducting materials, researchers tried to change material crystal

structures and surface properties. For the destruction of POPs, TiO

the commonly approved semiconductor material. The synthesis of

modied structures by combining other semiconductor materials with

ultrasound-assisted electronic deposition methods and techniques for

hydrothermal enhanced photocatalytic activity (Khani et al., 2019).

Furthermore, the heterogeneous photocatalysts play a key role in the

elimination of xenobiotics in water with super-hydrophilicity. The size,

surface, pore structure and pore volume of the semiconductive material

are the parameters that improve catalysis (Dong et al., 2015). Various

nano photocatalysts are set for the degradation of xenobiotics (Table 3).

2.3. Different types of nanomaterials in xenobiotic treatment

2.3.1. Nano-adsorbents in xenobiotics treatment

Carbon-based nano-adsorbents are widely used, such as activated

carbon, porous carbon, graphitized carbon and carbon nanotubes. Due

to hydrophobic, electrostatic, hydrogen bonding and covalent bonding

interactions, the carbon-based nano-adsorbents interact with contami-

nants. Each form has, among other things, several adsorption sites that,

with their exibility and physical chemistry, can absorb organic pol-

lutants (Kurwadkar et al., 2019). Single-walled and multi-walled carbon

nanotubes have been engineered to generate high energy sites in recent

years by modifying their surface chemistry (Rushi, 2019). Magnetic

nanoparticles are used effectively for the removal from usable sorption

sites of toxic compounds that function efciently as porosity increases.

Magnetic carbon nanotubes prepared by a variety of steps may be used

to alter the surface through carbon dots. From the results, a high

adsorption rate with high reuse potential has been observed (Deng et al.,

2019). The sol-gel methods are focused on multiple-walled carbon

nanotubes with a negatively charged surface which is primarily used in

cationic pollution removal (Konicki and Pełech, 2019). Polymeric nano-

adsorbents are porous (Moharrami and Motamedi, 2020) and attached

to magnetic nanoparticles that form core shells. This form of synthesis

resulted in the successful implementation of hybrid structures for

removing high absorption heavy metal ions with a large pH range.

2.3.2. Nano-lters in xenobiotics treatment

Since the implementation of the electrospinning process, ltration

Table 3

Photocatalytic degradation for treatment of wastes using nano-composites.

Category of wastes Photocatalytic agent Light source References

Tetracycline Sulfa-methazine Carbon nitride- Salicylic acid photocatalyst Visible light (Zhou et al., 2019a)

Methyl orange dye TiO

activated carbon nanocomposite UV light (Rashed et al., 2017)

Rhodamine B MoS

based hybrid photocatalyst SnO

/Ag/MoS

Visible light (Lu et al., 2017)

Methylene Blue MoS

-ZnO heterostructure Solar light (RitikaKaur et al., 2018)

Tetracycline (TTC) Tungsten oxide (WO

) on carbon nano-tube (CNT) Visible light (Isari et al., 2020)

Gemioxacin Zn-Co-layered double hydroxide (LDH) nanostructures UV light (Gholami et al., 2020)

Ibuprofen BiOBr/Fe

@SiO

Visible light (Khan et al., 2019b)

Petrochemical wastewater TiO

and ZnO nanocomposites Visible light/Solar light (Ani et al., 2018)

Rhodamine B TiO

/CNTs/rGO composites UV–Vis light irradiation (Huang et al., 2018)

Indigo dye Graphene WO

nanocomposite Visible light (Khan et al., 2019a)

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

technology has achieved milestones. Nanolters help to lower the so-

lution’s ionic strength, reducing the organic pollutant hardness (Konicki

and Pełech, 2019). Different natural and synthetic polymers are used to

synthesize nanoporous membranes like polyvinyl uoride cellulose ac-

etate, polypropylene, polyacrylonitrile, etc. (Konicki and Pełech, 2019).

Nano-ltration work centered on a pressure-driven method that is ef-

cient in removing components in low molecular weight with size ranges

between 10 and 1 nm. It performs ltration based on hydrodynamics on

the membrane surface and membrane nanopores. The effectiveness of

the ltration depends highly on lter membrane charge, membrane

porosity and the membrane surface concentration polarisation (Abdel-

Fatah, 2018). Using electro-spinner technology for the development of

nano-brous membranes, high-quality interconnected, 3D membranes

are prepared (Vaz et al., 2019). Nanobers reject univalent, divalent and

multivalent ions effectively, so the most useful approach is for treating

arsenic components in potable water. Nano-ltration efciently elimi-

nates almost all dissolved salts under all ltration methods with lower

energy consumption and operating pressure (Le and Nunes, 2016). For

the removal of arsenic compounds, several nano-lter membranes are

available on a commercial scale (Tanne et al., 2019).

Nano-lters prepared with highly charged polyamide facilitate the

removal of arsenic compounds. Separation and elimination are typically

accomplished through physicochemical interactions between mem-

branes and pollutants, however, only nanoltration is possible in the

case of trace components such as pesticides. Nano-lters faced limita-

tions for dissolved organic compounds and uncharged pesticides

because of the spectrum of their molecular weights and the hydropho-

bicity nature of pesticide molecules. The nano-lter membrane was

rejected by 11 different forms of pesticides, including aromatic, hydro-

phobic and phenol compounds, and the polarity of the pesticides

affected membrane ltration capacity. The separation of charged pes-

ticides is effective since it is relatively close to membranes. Thus, the

nanolters with high hydrophilicity are prepared with non-polar

membranes to avoid organic fouling (Abdel-Fatah, 2018; Liu et al.,

2016).

2.3.3. Nano-bers in xenobiotics treatment

Membrane ltration plays an important part in water purication as

traditional methods for water treatment, such as occulation, sedi-

mentation, coagulation and activated carbon cannot remove organic

contaminants to meet the required conditions (Ezugbe and Rathilal,

2020). Diverse natural and synthetic polymers are used for nanopore

membrane syntheses, such as polyvinyl uoride, polypropylene, poly-

acrylonitrile, and these nanobers are effective in the removal of

wastewater micropollutants. Due to their loose bundles compared to

tubes and particles, nanobers have stable adsorption structures. The

adsorption of pesticide contaminants through molecular propagation

mechanisms is especially relevant. Nano-brous membranes used to

adsorb atrazine herbicides are polymerized to pyrrole. Nanobers made

from semi-conducting materials with a photocatalytic property can be

used for the treatment of industrial toxic chemicals. Composite nano-

bers made of titanium dioxide and polymers with graphene have a very

strong photocatalytic effect on various dye compound degradation. The

presence of sodium ions and calcium ions was strongly affected by the

removal of arsenic, as the contact with the membrane changed the ionic

potential of the membrane (Phan, 2020).

In wastewater treatment, these nanobers are effective in the purg-

ing of micro-pollutants which are endocrinologically active in the

environment (Khalil and Sch¨

afer, 2021). Carbon nanobers made of

polyacrylonitrile by the adsorption of pharmaceutical antibiotics using

electrical spinning techniques (Ciproaxin and Bisphenol) are found and

the overall absorbance ability is enhanced by a decrease of molecular

dimensions (Li et al., 2015). Nanobers used for the adsorption of

atrazine herbicide are polymerized on the PA6 nano-bres (Khalil and

Sch¨

afer, 2021). For the preparation of ultra-thin nanolms, the bio-

polysaccharide cellulose obtained from the bacterial cells is used. It

has been covered with a molecule of cyclodextrin and used for water

washing. In this lm, excellent adsorbents are found for removing

different POPs such as phenol, bisphenol A (BPA) and glyphosate (2, 4-

DCP). With excellent reusable property, the product demonstrated

optimal adsorption over a large variety of pH (Khalil and Sch¨

afer, 2021).

2.3.4. Nanocomposites in xenobiotics treatment

Nano-composites are organic matrices that are strongly inuenced in

contrast to micro-composite and monolithic agents by their adsorption

of contaminants (Srivastava et al., 2020). New hybrid matrices were

developed to sequester contaminants and to release toxic payload ef-

ciently through the combination of tunable properties, such as electrical,

mechanical and magnet properties. Due to their recycling ability in

comparison with other materials, nanocomposites acted as attractive

pollutant removal materials (Guerra et al., 2018). Nanocomposites can

be generated through a range of techniques such as co-precipitation

(Sahu et al., 2018), hydrothermal thermal deposition synthesis (Nas-

rollahi et al., 2019), sol-gel synthesis (Jaramillo-Fierro et al., 2020),

microwave synthesis (Omo-Okoro et al., 2020), chemical vapor depo-

sition (Omo-Okoro et al., 2020), surface-modication (Kumar et al.,

2017) and energy-efcient ball milling (Wei et al., 2020). Nano-

composite xenobiotic removal using adsorbents, ion exchangers, or

photocatalysts has many benets, its stability also poses challenges in

applications. There is a possibility of leaching of metal ions from the

nanocomposites occurs; so, the environmental maintenance cost and

production cost limits the commercial production of the nano-

composites. Different types of nanocomposites employed in the degra-

dation of xenobiotics are represented in the Fig. 2.

2.3.4.1. Graphene-based nanocomposites. Graphene is a carbon nano-

composite allotrope used predominantly in the treatment of inorganic

contaminants and oil hydrocarbons. It has many structural variations

and functions based on adsorption. The derivatives from carbon mate-

rials are produced to solve the problems because the activated carbon is

unable to eradicate and it is a persistent organic contaminant. As a

sorption material for the elimination of aromatic pollutants graphene

nanocomposites are fabricated in various forms (Zhou et al., 2019b).

The improved adsorption potential of phenanthrene compounds and

persistent contaminants is seen in nanoporous graphene as shown by the

BET (Brunauer–Emmett–Teller) performance. This is due to the presence

of delocalized

-electron in their structures, which interact with similar

stacking interaction in the aromatic rings of the pollutants. Since gra-

phene has functional oxygen-bearing groups on its surface, cationic

metallic contaminants such as cadmium, chromium and lead adsorption

are affected by their exponential abilities. This in turn also inuences the

adsorption capacity of cationic metallic pollutants such as cadmium,

chromium, and lead exponentially. Fe

-rGO nanocomposites contain

layers of graphene with high surface area helps in the removal of lead

and arsenic compounds (Vuong Hoan et al., 2016). High recyclability

was observed with this nano-composite helps in the removal of rhoda-

mine compounds (Vo et al., 2020). Iron functionalized with graphene

oxide has been used for the adsorption of fulvic acid efciently than

activated carbon (Ray et al., 2017). Amine functionalized graphene

nanocomposites are used for the removal of phenolic pollutants (Nimita

Jebaranjitham et al., 2019). Functionalization of the graphene nano-

composites with various compounds such as thiourea dioxide and iron

(III) oxide and tested for its adsorptive capacity with tetracycline pol-

lutants in the water. It is observed that thiourea possesses increased

adsorption due to the hydrophobic interactions with tetracycline mol-

ecules when compared with the magnetite compound (Lin et al., 2013).

Cellulose-graphene oxide adsorbent has been studied for its adsorption

capacity of the pesticide pollutant ametryn by Zhang and co-workers,

who observed that the adsorption rate was seven times less when

compared with the Fe

-graphene oxide when it is maintained at a

sample pH of about 5 (Zhang et al., 2015). From the results, it is

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

observed that the magnetite nanocomposites are effectively doing the

adsorption process when compared with graphene oxide

nanocomposites.

2.3.4.2. Magnetic nanocomposites. Iron (III) oxide is successfully used to

treat photocatalytic degradation of persistent organic pollutant

ibuprofen, impregnated with nanorods of Bi

. This nano-composite

can be recycled magnetically and reused with a higher efciency rate

ve times than other nanocomposites (Xia and Lo, 2016). Magnetic

nanoparticle embedded with activated carbon has been used for the

treatment of dyes in the order of adsorption efciency range for red basic

than nylosan blue and chromazurol (Muntean et al., 2018). For the

removal of the arsenic compounds self-assembled nanocomposites,

prepared using magnetic particles and silica. To prepare TiO

/grapheme

oxide/CuFe

reusable nanopropylene, simple ball milling technology

was utilized, adding the magnetic property to the CuFe

compound

that enhances photocatalytic further (Ismael et al., 2020). The photo-

catalyst allows 17 pesticide residues, which remain in the atmosphere

under UV radiation treatment, to be degraded. Polycarrageenine co-

polymers with polyvinyl acetate and Fe

have been tested with a

crystal violet dye solution to generate nanocomposite hydrogels and

their adsorption ability. The ndings show that the adsorption efciency

decreases with the ionic strength of crystal violet solution and increases

with the rise in carrageenin concentration (Mansoori et al., 2016).

2.3.4.3. Polymer clay nanocomposites. The nano polymeric structure

consists of natural or synthetic polymers that serve as a matrix, and

another compound is used to create polymer nanocomposites with a

ller material (clay). The matrix (polymer) used is the determining

factor in the degradation process; because, during chemical reactions

that take place at higher temperatures it is structurally modied (de

Oliveira, 2019). Because of the substantial technological advances, ef-

forts have been made to develop polymers that display excellent

temperature resistance. These thermo-resistant polymers are used to

apply xenobiotic component degradation in the environment (Pathak

and Navneet, 2017). Divinylbenzene was shown to be an extremely

adsorbed polystyrene matrix, lled with phenol, chlorophenol and

nitrophenol. Montmorillonite (MMT)-embedded alginate nano-

composite has been used to extract 4 nitrophenols and copper. The ef-

ciency of the degradation depends on the extent of the ll

encapsulation in the matrix. Polymer Clay (PC) poly(4-vinylepyridin-

costyrene) composite and Poly-di-allyl-Dimethylammonium Chloride

(PDADMAC) polymers are successfully used to minimize the concen-

tration of atrazine pesticide in MMT clay (Kohay et al., 2015). Com-

posite of magnetite/bentonite acts as an adsorbent mixture used for the

removal of pharmaceutical compound nitrofurazone content in the

water to an extent of 50% (Alekseeva et al., 2019). Adsorption is acti-

vated based on the temperature changes maintained during the process

which was studied using MMT (SWy-2)–chitosan bio-nano composites

(SW–CH) in the treatment of clopyralid from the aqueous solutions. The

removal efciency was higher due to the use of bio-polysaccharide in the

nanocomposite preparations (Alekseeva et al., 2019). Calcium alginate

beads nanocomposites loaded with iron oxide nanoparticles are used for

the adsorption of ortho nitrophenol compounds and maximum adsorp-

tion was taking place at a pH around 2 with a removal efciency of 96%

(Saif et al., 2019). Perlite beads coated with chitosan nanocomposites

have been shown higher adsorption rates at a pH of 7.0 (Parlayici,

2019). Poly (4-vinyl pyridine-co-styrene) and poly diallyl dimethy-

lammonium chloride with MMT nanocomposites were effective for the

adsorption of both trichlorophenol and trinitrophenol pollutant (Ding

et al., 2016).

2.4. Nanosponges in xenobiotic treatment

The earlier studies on cyclodextrin polymers indicate that cyclo-

dextrin polymers have shown that organic and apolar contaminants are

Fig. 2. Types of nanocomposites in pollutant degradation.

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

being extracted in sections of one trillion while zeolites and activated CO

in ppm amounts are removed. The cyclodextrin adsorption quality has

insolubility and will thus not improve even if it is recycled a few times.

Cyclodextrin compounds have interstitial pores in the internal cavities

where molecules of the host are bound, and they help to trap the hy-

drophobic molecules. This property supports them in various research

applications, especially for environmental applications. Cyclodextrin

nanosponges are applied for the sorption, even when present at the

smallest concentration, of chlorinated aromatic compounds such as 4-

chlorophenoxyacetic acid and 2,3,4,6-tetrachlorophenol from aquatic

solutions (Salazar et al., 2018). The layering of magnetically engineered

nanoparticles on sponges enhances the polymer properties and can be

obtained after pesticide sequestration is full. Further research has shown

the efciency of cyclodextrin nanosponges, impregnating the polycyclic

aromatic hydrocarbons (PAHs), tri-halogen methanes (THMs), mono-

aromatic hydrocarbons (BTX) and pesticides (simazine) with greater

efciencies on ceramic porous lter membranes. Cyclodextrin de-

rivatives (CDNS) were used to prepare nanosponges that act as rhoda-

mine B sorbents (Li et al., 2020).

CDNS’ ability for adsorption varies depending on the structure of the

dye. The photocatalytic degradation of phenol has been tested in beta

cyclodextrin-nanosponge polyurethanes embedded in titanium-dioxide/

silver nanoparticles (Leudjo Taka et al., 2017). Cyclodextrin nano-

sponges can be strengthened to make composites that are used for

treating wastewater pollutants possible by functioning with nano-

polymeric beads, nano-part, dendrimers, nanomembranes, nanobers,

and carbon nanotubes. Synthetic nanosponge made from pure carbon

nanotubes is used for remediation of oil pollutants from the water. Nano-

sponges retain oil for recovery and reuse. Cyclodextrin-based, highly

cross-linked polymers made of two organo-clays (Dellite 67G and Dellite

43B used for the preparation of nanosponge) are used for the degrada-

tion of triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) with a

removal efciency of about 92% (V´

azquez-Nú˜

nez et al., 2020)

2.5. Nano-zeolites in xenobiotics treatment

Zeolites are natural microporous materials with a high potential for

ion exchange and were considered to be smart alternatives for the

remedy of dye contaminants. Efforts have been made to enhance the

ionic properties of zeolite and to alter its catalytic level and to degrade

waste (Li et al., 2017). But the use of zeolite as an adsorbent is restricted

because of certain characteristics: (i) very low permeability, (ii) loss of

adsorption potential when exposed to humidity in the air, and (iii) dif-

culty in removing highly suspended solids (Moosavifar et al., 2020).

Cadmium ions have been extracted with higher efciency for electro-

spinning of polyvinyl alcohol/zeolite nano adsorbents (Habiba et al.,

2017). The latest studies have shown the ability to extract the inorganic

cation and hydrophobic organic through surface alteration of natural

zeolites (Shi et al., 2018).

2.6. Nanosensors in xenobiotics treatment

Initially, the researchers made an effort to develop sensors for the

identication of pollutants in the atmosphere and the wastewater.

Nanotechnology-based microelectromechanical devices and nano-

contact sensors have been developed in miniature sizes for the detection

of pollutants based on environmental parameters (Willner and Vikes-

land, 2018); Nanotechnology has come to a step forward to degradation

along with the detection of pollutants, through photocatalysis using

semiconductor-based nanostructures (Willner and Vikesland, 2018).

Manganese doped zinc oxide nanowires have been used for the treat-

ment of harmful pesticide pollutants into harmless compounds such as

carbon dioxide, nitrogen and water in presence of visible light (Chen

et al., 2016). A cylindrical photochemical reactor with aqueous TiO

dispersions has been used for the degradation of (3,6-dichloro-2-

methoxy benzoic acid) in presence of a solar simulator (Andronic et al.,

2016). Nanolm sensors made of titanium dioxide thin lms have been

used for the degradation of endosulfan upon exposure to UV light within

45 min (Wang et al., 2016). Nanosensors are made of semiconductors

which are having the ability to identify the herbicide pollutants based on

the samples picked from the land. Complete adsorption and degradation

of the pollutants take place upon photodegradation (Saini et al., 2017).

2.7. Metal and metal-oxide nanoparticles in xenobiotics treatment

Metal nanoparticles gained much attraction over years in the treat-

ment of pollutants due to their nontoxic nature towards the environment

(Singh et al., 2018). Metals and metal oxide nanoparticles are broadly

applied in the removal of pesticide pollutants as they are having a large

number of surface reaction sites. They also can absorb the pollutants as

well as convert them into the less hazardous product so that it doesn’t

cause any harm to the environment. Particle size plays a major role in

the remediation of the pollutant due to the size quantization property of

the nanomaterials (Chavali and Nikolova, 2019). Graphene oxide

nanoparticles have an ample amount of chemically bonded oxygen on

the surface so that they can able to bind to the metal ions due to elec-

trostatic interactions; this helps to promote the reactivity of graphene

oxide nanoparticles with arsenic metal ion pollutants make them

immobilize to the remediation to occur (Baraga˜

no et al., 2020).

Organophosphorous pesticides are effectively removed by the nano-

metal oxide nanoparticles and alumina (Rani and Shanker, 2018a).

Nonpolar pesticides are removed by C-18 impregnated magnetic nano-

particles. Zinc oxide nanoparticles are highly efcient in the removal of

many organic dyes and zinc oxide nanoparticles are successfully

employed for the complete removal of permethrin compounds through

rapid reactive adsorption mechanisms. Numerous works have been

carried out using different forms of iron oxide nanoparticles in the

removal of As (V) and As (III) pollutants (Rani and Shanker, 2018b).

Additionally, the zerovalent forms of iron oxide nanoparticles have been

applied for the treatment of industrial efuents containing metallic

pollutants such as selenium, arsenic, cadmium, chromium and lead from

the waste streams; nano zerovalent iron also possesses dechlorination of

halogenated pesticides, herbicides, radionuclides and organic com-

pounds. The nitroaromatic compounds such as atrazine, diazinon and

diuron can be converted into corresponding amines into very low con-

centrations with nZVI compounds (Pasinszki and Krebsz, 2020).

TiO

nanoparticles exhibit photocatalytic properties when they

interact with UV light irradiations. The hydroxyl radicals are released

upon excitation by the nanoparticles that interact with pesticides. From

the reports, it is studied that dicofol is one kind of chlorinated pesticide

that interacts with the titanium dioxide nanoparticles which will be

converted to less toxic chlorine compounds; almost all the chlorinated

pesticides will be degraded in a shorter duration. Surface modication of

the nanoparticles can be done by changing the size, doping of noble

metals, increasing the surface active sites and the shape of the nano-

particles to improve the adsorption capacity. Another frequently used

nanoparticle with high thermal stability is the nano alumina which is

mainly used for the removal of mercury pollutants. Silver nanoparticles

are designed with antimicrobial properties to nullify the issues that

occur by fouling of the membranes. The nanoparticles can change the

membrane qualities such as hydrophilicity, membrane permeability,

uniformity, the time of separation and fouling resistance (Mahmoudi

et al., 2019). Biogenic nanoparticles possess unique properties that are

successfully employed for the treatment of metal contaminated soil as

well as water without causing any side effects (Fang et al., 2019).

3. Benets and limitations for the adoption of nano-treatment

methods

The adoption of nano-treatment approaches for the removal of

contaminants from wastewater, advantages and limitations are outlined

in Fig. 3. Nanomaterials in the form of sorbents for the treatment of

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

contaminants are distinct. Temperature, pH, nano adsorbent doses and

contact time are the key factors affecting the treatment processes. In

recent years, there have been restrictions on the applications of nano-

technology. Each government has identied particular structures and

they are different for each country. Many of the challenges related to

pollution treatment are newly tackled in nanotechnology. The use of

nanomaterials provides bioavailability in the transport and processing

of contaminants in the environment. Biodegradable materials tend to be

a way to prevent bioaccumulation in the preparation of nanomaterials.

The new technology experiments have been performed to concentrate

on pollution capture at the site, as the problems of non-targeted pro-

cedures are avoided. Production of the engineered nanoparticles mainly

for the treatment of contaminants is prepared with special properties

such as targeted pollutant capturing, use of biodegradable raw materials

that can regenerate and recycle nanomaterials. The method of synthesis

should furthermore prevent the formation of agglomerates and stable

nanomaterials. Analysis of potential toxicity, the development of by-

products during synthesis and the costs of recovery should be given

considerable attention. Process design and optimization can be achieved

by knowing these procedures to produce possible nanomaterials for

contaminants removal in the environment.

Various researchers have attempted to remove the halogenated

xenobiotic compounds which are a major threat to the environment. For

this, the existing bioremediation technologies in combination with

nanotechnology approaches are employed to remove such compounds

from the surface layers of the ecosystem. In case of adverse natural

climatic conditions, the concentration levels of the xenobiotic may in-

crease or decrease, organisms become sensitive to eliminate the com-

ponents. Advancements in next-generation biotechnological tools and

the functionalization of nanomaterials and offer a feasible solution to

the remediation of pollutants in such conditions (V´

azquez-Nú˜

nez et al.,

2020). Though the removal has been done, some of the nanomaterials

have been released unintentionally which is undesirable for maintaining

a sustainable environment. On the other side, there is no evidence for

the safety of using the components at nanoscale. However, nano-

bioremediation techniques involve the concept of biological removal

methods which possess an advantage over the chemical treatment

methods in terms of degradation capabilities.

4. Challenges and perspectives

The release of xenobiotic chemicals is increasing in dose levels as the

consumers are increasing every year. Treatment of contaminants at

ground level and the surface water level has been done using conven-

tional techniques but they fail to meet the zero elimination of wastes.

Despite the chemical treatment technologies greater potential for the

removal of a xenobiotic compound, most of the aspects of feasibility and

safety have issues in the point of the economy. After the onset of

nanotechnology principles, there is a rise of innovative treatment op-

tions for the selective removal of wastes. From an environmental point

of view, nanomaterial usage has challenges in manufacturing methods

and applications. Different approaches have been tried to improve the

properties of the nanomaterial using engineering principles to avoid the

release and transport of nanoparticles in the environment.

Until now, most of the barriers faced in the treatment of xenobiotics

have been solved using nanotechnology under laboratory level experi-

ments. From the observations, it was found that the research could be

improved in the following objectives to improve the removal of xeno-

biotic compounds. The major ndings are: (i) surface properties of nano

adsorbents can be altered and it could be effectively utilized for

Fig. 3. Advances and limitations of adopting nano-treatment approaches in POPs and xenobiotic removal.

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

contaminant removal from the surface water, (ii) the ability of photo-

catalysts with interface properties for efcient degradation of dye-based

components, and (iii) the improvements could be done in terms of

reusability, material cost and a lifetime of nanomaterials using compu-

tational methods offer the possibility to develop materials with unique

functionalities.

5. Conclusions

In the light of future environmental and health safety legislation in

particular for wastewater restoration and recycling, xenobiotic trace

pollutants should be eliminated. To eliminate these emerging pollutants,

technological and economic factors are critical parameters for choosing

the appropriate treatment scheme. EDCs and PPCPs are degraded to a

great extent by the compound class and method of the treatment pro-

cedure. The government must make people aware of the POPs and make

them realize their deadly consequences. Researchers need to be moti-

vated to design more biodegradable nanomaterials to eliminate POPs in

an environmentally friendly manner in the future.

Declaration of Competing Interest

The authors declare that they have no known competing nancial

interests or personal relationships that could have appeared to inuence

the work reported in this paper.

Acknowledgements

The authors are thankful to The Management of Sri Venkateswara

College of Engineering, Sriperumbudur, India, Saveetha School of En-

gineering (SIMATS), Chennai, India and The Management, Vice-

Chancellor, Dean, SMNS and Head of Biological Sciences, The Copper-

belt University, Kitwe, Zambia for their constant support to complete the

review article. The Shaanxi Introduced Talent Research Funding

(A279021901), China and The Introduction of Talent Research Start-up

fund (No. 00700-Z101022001), College of Natural Resources and

Environment, Northwest A&F University, Yangling, Shaanxi Province

712100, China for the nancial support.

References

Abdel-Fatah, M.A., 2018. Nanoltration systems and applications in wastewater

treatment: review article. Ain Shams Eng. J. 9 (4), 3077–3092. https://doi.org/

10.1016/j.asej.2018.08.001.

Abdullah, H.B., Irmawati, R., Ismail, I., Yusof, N.A., 2020. Utilization of waste engine oil

for carbon nanotube aerogel production using oating catalyst chemical vapor

deposition. J. Clean. Prod. 261, 121188. https://doi.org/10.1016/j.

jclepro.2020.121188.

Adewuyi, A., 2020. Chemically modied biosorbents and their role in the removal of

emerging pharmaceutical waste in the water system. Water (Switzerland) 12, 1–31.

https://doi.org/10.3390/W12061551.

Alekseeva, O.V., Rodionova, A.N., Noskov, A.V., Agafonov, A.V., 2019. Bentonite/

magnetite composite for removal of nitrofurazone. Clays Clay Miner. 67 (6),

471–480. https://doi.org/10.1007/s42860-019-00037-w.

Andronic, L., Isac, L., Miralles-Cuevas, S., Visa, M., Oller, I., Duta, A., Malato, S., 2016.

Pilot-plant evaluation of TiO

and TiO

-based hybrid photocatalysts for solar

treatment of polluted water. J. Hazard. Mater. 320, 469–478. https://doi.org/

10.1016/j.jhazmat.2016.08.013.

Ani, I.J., Akpan, U.G., Olutoye, M.A., Hameed, B.H., 2018. Photocatalytic degradation of

pollutants in petroleum renery wastewater by TiO

- and ZnO-based photocatalysts:

Recent development. J. Clean. Prod. 205, 930–954. https://doi.org/10.1016/j.

jclepro.2018.08.189.

Asif, M.B., Hai, F.I., Kang, J., van de Merwe, J.P., Leusch, F.D.L., Price, W.E., Nghiem, L.

D., 2018. Biocatalytic degradation of pharmaceuticals, personal care products,

industrial chemicals, steroid hormones and pesticides in a membrane distillation-

enzymatic bioreactor. Bioresour. Technol. 247, 528–536. https://doi.org/10.1016/j.

biortech.2017.09.129.

Badmus, K.O., Tijani, J.O., Massima, E., Petrik, L., 2018. Treatment of persistent organic

pollutants in wastewater using hydrodynamic cavitation in synergy with advanced

oxidation process. Environ. Sci. Pollut. Res. 25 (8), 7299–7314. https://doi.org/

10.1007/s11356-017-1171-z.

Baraga˜

no, D., Forj´

an, R., Welte, L., Gallego, J.L.R., 2020. Nanoremediation of As and

metals polluted soils by means of graphene oxide nanoparticles. Sci. Rep. 10 (1)

https://doi.org/10.1038/s41598-020-58852-4.

Biel-Maeso, M., Corada-Fern´

andez, C., Lara-Martín, P.A., 2019. Removal of personal care

products (PCPs) in wastewater and sludge treatment and their occurrence in

receiving soils. Water Res. 150, 129–139. https://doi.org/10.1016/j.

watres.2018.11.045.

Cai, Z., Dwivedi, A.D., Lee, W.-N., Zhao, X., Liu, W., Sillanp¨

a¨

a, M., Zhao, D., Huang, C.-

H., Fu, J., 2018. Application of nanotechnologies for removing pharmaceutically

active compounds from water: development and future trends. Environ. Sci. Nano 5

(1), 27–47. https://doi.org/10.1039/c7en00644f.

Camargo-Perea, A.L., Rubio-Clemente, A., Pe˜

nuela, G.A., 2020. Use of ultrasound as an

advanced oxidation process for the degradation of emerging pollutants in water.

Water (Switzerland) 12, 1–23. https://doi.org/10.3390/W12041068.

Chakraborty, I., Sathe, S.M., Khuman, C.N., Ghangrekar, M.M., 2020.

Bioelectrochemically powered remediation of xenobiotic compounds and heavy

metal toxicity using microbial fuel cell and microbial electrolysis cell. Mater. Sci.

Energy Technol. 3, 104–115. https://doi.org/10.1016/j.mset.2019.09.011.

Chavali, M.S., Nikolova, M.P., 2019. Metal oxide nanoparticles and their applications in

nanotechnology. SN Appl. Sci. 1 (6) https://doi.org/10.1007/s42452-019-0592-3.

Chen, B., Chen, Z., Lv, S., 2011. A novel magnetic biochar efciently sorbs organic

pollutants and phosphate. Bioresour. Technol. 102 (2), 716–723. https://doi.org/

10.1016/j.biortech.2010.08.067.

Chen, M., Ren, L., Qi, K., Li, Q., Lai, M., Li, Y., Li, X., Wang, Z., 2020. Enhanced removal

of pharmaceuticals and personal care products from real municipal wastewater using

an electrochemical membrane bioreactor. Bioresour. Technol. 311, 123579. https://

doi.org/10.1016/j.biortech.2020.123579.

Chen, W.-H., Su, C.-C., Hsieh, H.-H., Chang, M.-F., Ho, M.-S., 2016. Dilute manganese-

doped ZnO nanowires for high photoelectrical performance. RSC Adv. 6 (94),

91216–91224. https://doi.org/10.1039/C6RA14208G.

Chen, X., Tang, R., Wang, Y., Yuan, S., Wang, W., Ali, I.M., Hu, Z.-H., 2021. Effect of

ultrasonic and ozone pretreatment on the fate of enteric indicator bacteria and

antibiotic resistance genes, and anaerobic digestion of dairy wastewater. Bioresour.

Technol. 320, 124356. https://doi.org/10.1016/j.biortech.2020.124356.

Chen, Z., Xu, J., Hu, D., Cui, Y., Wu, P., Ge, H., Jia, F., Xiao, T., Li, X., Su, H., Wang, H.,

Zhang, Y., 2018. Performance and kinetic model of degradation on treating

pharmaceutical solvent wastewater at psychrophilic condition by a pilot-scale

anaerobic membrane bioreactor. Bioresour. Technol. 269, 319–328. https://doi.org/

10.1016/j.biortech.2018.08.075.

Cook, M.M., Symonds, E.M., Gerber, B., Hoare, A., Van Vleet, E.S., Breitbart, M., 2016.

Removal of six estrogenic endocrine-disrupting compounds (EDCs) from municipal

wastewater using aluminum electrocoagulation. Water (Switzerland) 8. doi:

10.3390/w8040128.

Cuerda-correa, E.M., Alexandre-franco, M.F., Fern, C., 2020. Antibiotics from water. An

overview. Water 12, 1–50.

Daley, J.M., Paterson, G., Drouillard, K.G., 2014. Bioamplication as a bioaccumulation

mechanism for persistent organic pollutants (POPs) in wildlife. Rev. Environ.

Contam. Toxicol. 227, 107–155. https://doi.org/10.1007/978-3-319-01327-5_4.

Delforno, T.P., Moura, A.G.L., Okada, D.Y., Sakamoto, I.K., Varesche, M.B.A., 2015.

Microbial diversity and the implications of sulde levels in an anaerobic reactor used

to remove an anionic surfactant from laundry wastewater. Bioresour. Technol. 192,

37–45. https://doi.org/10.1016/j.biortech.2015.05.050.

Deng, D., Tam, N.F., 2015. Isolation of microalgae tolerant to polybrominated diphenyl

ethers (PBDEs) from wastewater treatment plants and their removal ability.

Bioresour. Technol. 177, 289–297. https://doi.org/10.1016/j.biortech.2014.11.103.

Deng, Y., Ok, Y.S., Mohan, D., Pittman Jr., C.U., Dou, X., 2019. Carbamazepine removal

from water by carbon dot-modied magnetic carbon nanotubes. Environ. Res. 169,

434–444. https://doi.org/10.1016/j.envres.2018.11.035.

Deng, Y., Zhao, R., 2015. Advanced oxidation processes (AOPs) in wastewater treatment.

Curr. Pollut. Rep. 1 (3), 167–176. https://doi.org/10.1007/s40726-015-0015-z.

des Ligneris, E., Dum´

ee, L.F., Kong, L., 2018. Nanober-based materials for persistent

organic pollutants in water remediation by adsorption. Appl. Sci. 8. doi:10.3390/

app8020166.

Diamanti-Kandarakis, E., Bourguignon, J.-P., Giudice, L.C., Hauser, R., Prins, G.S., Soto,

A.M., Zoeller, R.T., Gore, A.C., 2009. Endocrine-disrupting chemicals: an Endocrine

Society scientic statement. Endocr. Rev. 30, 293–342. doi:10.1210/er.2009-0002.

Ding, C., Gong, D., Yu, P., Shao, J., Zhong, M.-E., 2016. Removal of quinclorac herbicide

from aqueous solution by chitosan/montmorillonite bionanocomposite. Desalin.

Water Treat. 57 (52), 24970–24981. https://doi.org/10.1080/

19443994.2016.1146919.

Dong, S., Feng, J., Fan, M., Pi, Y., Hu, L., Han, X., Liu, M., Sun, J., Sun, J., 2015. Recent

developments in heterogeneous photocatalytic water treatment using visible light-

responsive photocatalysts: a review. RSC Adv. 5 (19), 14610–14630. https://doi.

org/10.1039/C4RA13734E.

Donyinah, J.T.Z.E.-S.K., 2019. Degradation Pathways of Persistent Organic Pollutants

(POPs) in the Environment. IntechOpen, Rijeka, p. Ch. 3. doi:10.5772/

intechopen.79645.

Egorova, D.O., Buzmakov, S.A., Nazarova, E.A., Andreev, D.N., Demakov, V.A.,

Plotnikova, E.G., 2017. Bioremediation of hexachlorocyclohexane-contaminated soil

by the new Rhodococcus wratislaviensis strain Ch628. Water Air Soil Pollut. 228 (5)

https://doi.org/10.1007/s11270-017-3344-2.

Ezugbe, E.O., Rathilal, S., 2020. Membrane technologies in wastewater treatment: a

review. Membranes (Basel). 10. doi:10.3390/membranes10050089.

Fang, X., Wang, Y., Wang, Z., Jiang, Z., Dong, M., 2019. Microorganism assisted

synthesized nanoparticles for catalytic applications. Energies 12. doi:10.3390/

en12010190.

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

Garza-Lomb´

o, C., Posadas, Y., Quintanar, L., Gonsebatt, M.E., Franco, R., 2018.

Neurotoxicity linked to dysfunctional metal ion homeostasis and xenobiotic metal

exposure: redox signaling and oxidative stress. Antioxid. Redox Signal. 28 (18),

1669–1703. https://doi.org/10.1089/ars.2017.7272.

George, B., You, D., Joy, M.S., Aleksunes, L.M., 2017. Xenobiotic transporters and kidney

injury. Adv. Drug Deliv. Rev. 116, 73–91. https://doi.org/10.1016/j.

addr.2017.01.005.

Gholami, P., Khataee, A., Soltani, R.D.C., Dinpazhoh, L., Bhatnagar, A., 2020.

Photocatalytic degradation of gemioxacin antibiotic using Zn-Co-LDH@biochar

nanocomposite. J. Hazard. Mater. 382, 121070. https://doi.org/10.1016/j.

jhazmat.2019.121070.

Giwa, A., Yusuf, A., Balogun, H.A., Sambudi, N.S., Bilad, M.R., Adeyemi, I.,

Chakraborty, S., Curcio, S., 2021. Recent advances in advanced oxidation processes

for removal of contaminants from water: a comprehensive review. Process Saf.

Environ. Prot. 146, 220–256. https://doi.org/10.1016/j.psep.2020.08.015.

Gonz´

alez-Abradelo, D., P´

erez-Llano, Y., Peidro-Guzm´

an, H., S´

anchez-Carbente, M.D.R.,

Folch-Mallol, J.L., Aranda, E., Vaidyanathan, V.K., Cabana, H., Gunde-

Cimerman, N., Batista-García, R.A., 2019. First demonstration that ascomycetous

halophilic fungi (Aspergillus sydowii and Aspergillus destruens) are useful in xenobiotic

mycoremediation under high salinity conditions. Bioresour. Technol. 279, 287–296.

https://doi.org/10.1016/j.biortech.2019.02.002.

Guerra-Rodríguez, S., Rodríguez, E., Singh, D.N., Rodríguez-Chueca, J., 2018.

Assessment of sulfate radical-based advanced oxidation processes for water and

wastewater treatment: a review. Water (Switzerland) 10. doi:10.3390/w10121828.

Guerra, F.D., Attia, M.F., Whitehead, D.C., Alexis, F., 2018. Nanotechnology for

environmental remediation: materials and applications. Molecules 23. doi:10.3390/

molecules23071760.

Habiba, U., A, A.M., Salleh, A., Ang, B.C., 2017. Chitosan/(polyvinyl alcohol)/zeolite

electrospun composite nanobrous membrane for adsorption of Cr6+, Fe3+and Ni2

+. J. Hazard. Mater. 322, 182–194. https://doi.org/10.1016/j.

jhazmat.2016.06.028.

Hoan, N.T.V., Anh Thu, N.T., Duc, H.V., Cuong, N.D., Quang Khieu, D., Vo, V., 2016. Fe 3

O 4 /reduced graphene oxide nanocomposite: synthesis and its application for toxic

metal ion removal. J. Chem. 2016, 1–10. https://doi.org/10.1155/2016/2418172.

Huang, Y., Chen, D., Hu, X., Qian, Y., Li, D., 2018. Preparation of TiO2/carbon

nanotubes/reduced graphene oxide composites with enhanced photocatalytic

activity for the degradation of rhodamine B. Nanomaterials 8, 1–9. https://doi.org/

10.3390/nano8060431.

Isari, A.A., Mehregan, M., Mehregan, S., Hayati, F., Rezaei Kalantary, R., Kakavandi, B.,

2020. Sono-photocatalytic degradation of tetracycline and pharmaceutical

wastewater using WO

/CNT heterojunction nanocomposite under US and visible

light irradiations: a novel hybrid system. J. Hazard. Mater. 390, 122050. https://doi.

org/10.1016/j.jhazmat.2020.122050.

Ismael, A.M., El-Shazly, A.N., Gaber, S.E., Rashad, M.M., Kamel, A.H., Hassan, S.S.M.,

2020. Novel TiO 2 /GO/CuFe 2 O 4 nanocomposite: a magnetic, reusable and visible-

light-driven photocatalyst for efcient photocatalytic removal of chlorinated

pesticides from wastewater. RSC Adv. 10 (57), 34806–34814. https://doi.org/

10.1039/d0ra02874f.

Jaramillo-Fierro, X., P´

erez, S.G., Jaramillo, H.A., Cabello, F.M., 2020. Synthesis of the

zntio3 /tio2 nanocomposite supported in ecuadorian clays for the adsorption and

photocatalytic removal of methylene blue dye. Nanomaterials 10, 1–20. https://doi.

org/10.3390/nano10091891.

Jung, K.-W., Ahn, K.-H., 2016. Fabrication of porosity-enhanced MgO/biochar for

removal of phosphate from aqueous solution: application of a novel combined

electrochemical modication method. Bioresour. Technol. 200, 1029–1032. https://

doi.org/10.1016/j.biortech.2015.10.008.

Kadam, A., Saratale, R.G., Shinde, S., Yang, J., Hwang, K., Mistry, B., Saratale, G.D.,

Lone, S., Kim, D.-Y., Sung, J.-S., Ghodake, G., 2019. Adsorptive remediation of cobalt

oxide nanoparticles by magnetized

-cellulose bers from waste paper biomass.

Bioresour. Technol. 273, 386–393. https://doi.org/10.1016/j.biortech.2018.11.041.

Kang, J., Zhou, L.i., Duan, X., Sun, H., Ao, Z., Wang, S., 2019. Degradation of cosmetic

microplastics via functionalized carbon nanosprings. Matter 1 (3), 745–758. https://

doi.org/10.1016/j.matt.2019.06.004.

Kar, P., Shukla, K., Jain, P., Sathiyan, G., Gupta, R.K., 2020. Semiconductor based

photocatalysts for detoxication of emerging pharmaceutical pollutants from

aquatic systems: a critical review. Nano Mater. Sci. https://doi.org/10.1016/j.

nanoms.2020.11.001.

Khalil, A.M., Sch¨

afer, A.I., 2021. Cross-linked β-cyclodextrin nanober composite

membrane for steroid hormone micropollutant removal from water. J. Membr. Sci.

618, 118228. https://doi.org/10.1016/j.memsci.2020.118228.

Khan, M., Fung, C.S.L., Kumar, A., Lo, I.M.C., 2019a. Magnetically separable BiOBr/

@SiO

for visible-light-driven photocatalytic degradation of ibuprofen:

mechanistic investigation and prototype development. J. Hazard. Mater. 365,

733–743. https://doi.org/10.1016/j.jhazmat.2018.11.053.

Khan, M.Y., Ahmad, M., Sadaf, S., Iqbal, S., Nawaz, F., Iqbal, J., 2019b. Visible light

active indigo dye/graphene/WO

nanocomposites with excellent photocatalytic

activity. J. Mater. Res. Technol. 8 (3), 3261–3269. https://doi.org/10.1016/j.

jmrt.2019.05.015.

Khan, S., Ullah, M.W., Siddique, R., Nabi, G., Manan, S., Yousaf, M., Hou, H., 2016. Role

of recombinant DNA technology to improve life. Int. J. Genomics 2016, 1–14.

https://doi.org/10.1155/2016/2405954.

Khani, Z., Schieppati, D., Bianchi, C.L., Bofto, D.C., 2019. The sonophotocatalytic

degradation of pharmaceuticals in water by MnOx-TiO

systems with tuned band-

gaps. Catalysts 9, 1–20. https://doi.org/10.3390/catal9110949.

Kinidi, L., Tan, I.A.W., Abdul Wahab, N.B., Tamrin, K.F.B., Hipolito, C.N., Salleh, S.F.,

2018. Recent development in ammonia stripping process for industrial wastewater

treatment. Int. J. Chem. Eng. 2018, 1–14. https://doi.org/10.1155/2018/3181087.

Kodama, S., Matsumoto, S., Wang, D., Namihira, T., Akiyama, H., 2015. Treatment of

Persistent Organic Pollutants in Wastewater by Nano-Seconds Pulsed Discharge

Plasma. In: 2015 IIAI 4th International Congress on Advanced Applied Informatics,

pp. 695–698. https://doi.org/10.1109/IIAI-AAI.2015.215.

Kohay, H., Izbitski, A., Mishael, Y.G., 2015. Developing polycation-clay sorbents for

efcient ltration of diclofenac: effect of dissolved organic matter and comparison to

activated carbon. Environ. Sci. Technol. 49 (15), 9280–9288.

Konicki, W., Pełech, I., 2019. Removing cationic dye from aqueous solutionsusing as-

grown and modied multi-walledcarbon nanotubes. Pol. J. Environ. Stud. 28 (2),

717–727. https://doi.org/10.15244/pjoes/85069.

Kumar, D., Pandey, J., Raj, V., Kumar, P., 2017. A review on the modication of

polysaccharide through graft copolymerization for various potential applications.

TOMCJ 11 (1), 109–126. https://doi.org/10.2174/1874104501711010109.

Kumar, S., Kaushik, G., Dar, M.A., Nimesh, S., L´

opez-Chuken, U.J., Villarreal-Chiu, J.F.,

2018. Microbial degradation of organophosphate pesticides: a review. Pedosphere

28 (2), 190–208. https://doi.org/10.1016/S1002-0160(18)60017-7.

Kurwadkar, S., Hoang, T.V., Malwade, K., Kanel, S.R., Harper Jr., W.F., Struckhoff, G.,

2019. Application of carbon nanotubes for removal of emerging contaminants of

concern in engineered water and wastewater treatment systems. Nanotechnol.

Environ. Eng. 4 (1) https://doi.org/10.1007/s41204-019-0059-1.

La Merrill, M., Emond, C., Kim, M.J., Antignac, J.-P., Le Bizec, B., Cl´

ement, K.,

Birnbaum, L.S., Barouki, R., 2013. Toxicological function of adipose tissue: focus on

persistent organic pollutants. Environ. Health Perspect. 121 (2), 162–169.

Le, N.L., Nunes, S.P., 2016. Materials and membrane technologies for water and energy

sustainability. Sustain. Mater.Technol. 7, 1–28. https://doi.org/10.1016/j.

susmat.2016.02.001.

Le, T.T., Nguyen, K.-H., Jeon, J.-R., Francis, A.J., Chang, Y.-S., 2015. Nano/bio treatment

of polychlorinated biphenyls with evaluation of comparative toxicity. J. Hazard.

Mater. 287, 335–341. https://doi.org/10.1016/j.jhazmat.2015.02.001.

Leong, Y.K., Chang, J.-S., 2020. Bioremediation of heavy metals using microalgae: recent

advances and mechanisms. Bioresour. Technol. 303, 122886. https://doi.org/

10.1016/j.biortech.2020.122886.

Leudjo Taka, A., Pillay, K., Yangkou Mbianda, X., 2017. Nanosponge cyclodextrin

polyurethanes and their modication with nanomaterials for the removal of

pollutants from waste water: a review. Carbohydr. Polym. 159, 94–107. https://doi.

org/10.1016/j.carbpol.2016.12.027.

Li, L., Liu, H., Li, W., Liu, K., Tang, T., Liu, J., Jiang, W., 2020. One-step synthesis of an

environment-friendly cyclodextrin-based nanosponge and its applications for the

removal of dyestuff from aqueous solutions. Res. Chem. Intermed. 46 (3),

1715–1734. https://doi.org/10.1007/s11164-019-04059-w.

Li, X., Chen, S., Fan, X., Quan, X., Tan, F., Zhang, Y., Gao, J., 2015. Adsorption of

ciprooxacin, bisphenol and 2-chlorophenol on electrospun carbon nanobers: In

comparison with powder activated carbon. J. Colloid Interface Sci. 447, 120–127.

https://doi.org/10.1016/j.jcis.2015.01.042.

Li, Y.i., Li, L., Yu, J., 2017. Applications of zeolites in sustainable chemistry. Chem 3 (6),

928–949. https://doi.org/10.1016/j.chempr.2017.10.009.

Lin, Y.-C., Lee, H.-S., 2010. Effects of TiO2 coating dosage and operational parameters on

a TiO2/Ag photocatalysis system for decolorizing Procion red MX-5B. J. Hazard.

Mater. 179 (1-3), 462–470. https://doi.org/10.1016/j.jhazmat.2010.03.026.

Lin, Y., Xu, S., Li, J., 2013. Fast and highly efcient tetracyclines removal from

environmental waters by graphene oxide functionalized magnetic particles. Chem.

Eng. J. 225, 679–685.

Litskas, V.D., Karamanlis, X.N., Prousali, S.P., Koveos, D.S., 2019. The xenobiotic

doxycycline affects nitrogen transformations in soil and impacts earthworms and

cultivated plants. J. Environ. Sci. Health Part A 54 (14), 1441–1447.

Liu, J., Song, Y., Tang, M., Lu, Q., Zhong, G., 2020. Enhanced dissipation of xenobiotic

agrochemicals harnessing soil microbiome in the tillage-reduced rice-dominated

agroecosystem. J. Hazard. Mater. 398, 122954. https://doi.org/10.1016/j.

jhazmat.2020.122954.

Liu, J., Yuan, J., Ji, Z., Wang, B., Hao, Y., Guo, X., 2016. Concentrating brine from

seawater desalination process by nanoltration–electrodialysis integrated membrane

technology. Desalination 390, 53–61. https://doi.org/10.1016/j.desal.2016.03.012.

Lu, D., Wang, H., Zhao, X., Kondamareddy, K.K., Ding, J., Li, C., Fang, P., 2017. Highly

efcient visible-light-induced photoactivity of Z-scheme g-C 3 N 4 /Ag/MoS 2

ternary photocatalysts for organic pollutant degradation and production of

hydrogen. ACS Sustain. Chem. Eng. 5 (2), 1436–1445. https://doi.org/10.1021/

acssuschemeng.6b02010.

Luo, W., Xie, M., Song, X., Guo, W., Ngo, H.H., Zhou, J.L., Nghiem, L.D., 2018.

Biomimetic aquaporin membranes for osmotic membrane bioreactors: membrane

performance and contaminant removal. Bioresour. Technol. 249, 62–68. https://doi.

org/10.1016/j.biortech.2017.09.170.

Mahmoudi, E., Ng, L.Y., Ang, W.L., Chung, Y.T., Rohani, R., Mohammad, A.W., 2019.

Enhancing morphology and separation performance of polyamide 6,6 membranes by

minimal incorporation of silver decorated graphene oxide nanoparticles. Sci. Rep. 9

(1) https://doi.org/10.1038/s41598-018-38060-x.

Manikandan, S., Karmegam, N., Subbaiya, R., Karthigadevi, G., Arulvel, R.,

Ravindran, B., Kumar Awasthi, M., 2021. Emerging nano-structured innovative

materials as adsorbents in wastewater treatment. Bioresour. Technol. 320, 124394.

https://doi.org/10.1016/j.biortech.2020.124394.

Mansoori, Y., Khodayari, A., Banaei, A., Mirzaeinejad, M., Azizian-Kalandaragh, Y.,

Pooresmaeil, M., 2016. Fe

–PVAc nanocomposites: surface modication of

sonochemically prepared magnetite nanoparticles via chemical grafting of poly

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

(vinyl acetate). RSC Adv. 6 (54), 48676–48683. https://doi.org/10.1039/

C5RA26783H.

Meena, R.S., Kumar, S., Datta, R., Lal, R., Vijayakumar, V., Brtnicky, M., Sharma, M.P.,

Yadav, G.S., Jhariya, M.K., Jangir, C.K., Pathan, S.I., Dokulilova, T., Pecina, V.,

Marfo, T.D., 2020. Impact of agrochemicals on soil microbiota and management: a

review. Land 9. doi:10.3390/land9020034.

Megson, D., Reiner, E.J., Jobst, K.J., Dorman, F.L., Robson, M., Focant, J.-F., 2016.

A review of the determination of persistent organic pollutants for environmental

forensics investigations. Anal. Chim. Acta 941, 10–25. https://doi.org/10.1016/j.

aca.2016.08.027.

Moharrami, P., Motamedi, E., 2020. Application of cellulose nanocrystals prepared from

agricultural wastes for synthesis of starch-based hydrogel nanocomposites: efcient

and selective nanoadsorbent for removal of cationic dyes from water. Bioresour.

Technol. 313, 123661. https://doi.org/10.1016/j.biortech.2020.123661.

Moosavifar, M., Heidari, S.M., Fathyunes, L., Ranjbar, M., Wang, Y., Arandiyan, H., 2020.

Photocatalytic degradation of dye pollutant over FeTPP/NaY zeolite nanocomposite.

J. Inorg. Organomet. Polym. 30 (5), 1621–1628. https://doi.org/10.1007/s10904-

019-01277-y.

Moreira, F.C., Boaventura, R.A.R., Brillas, E., Vilar, V.J.P., 2017. Electrochemical

advanced oxidation processes: a review on their application to synthetic and real

wastewaters. Appl. Catal. B Environ. 202, 217–261. https://doi.org/10.1016/j.

apcatb.2016.08.037.

Muntean, S.G., Nistor, M.A., Muntean, E., Todea, A., Ianos¸ , R., P˘

acurariu, C., 2018.

Removal of colored organic pollutants from wastewaters by magnetite/carbon

nanocomposites: single and binary systems. J. Chem. 2018, 1–16. https://doi.org/

10.1155/2018/6249821.

Nascimento, C.O.C., Veit, M.T., Pal´

acio, S.M., Gonçalves, G.C., Fagundes-Klen, M.R.,

2019. Combined application of coagulation/occulation/sedimentation and

membrane separation for the treatment of laundry wastewater. Int. J. Chem. Eng.

2019, 1–13. https://doi.org/10.1155/2019/8324710.

Nasrollahi, Z., Ebrahimian Pirbazari, A., Hasan-Zadeh, A., Salehi, A., 2019. One-pot

hydrothermal synthesis and characterization of magnetic nanocomposite of titania-

deposited copper ferrite/ferrite oxide for photocatalytic decomposition of methylene

blue dye. Int. Nano Lett. 9 (4), 327–338. https://doi.org/10.1007/s40089-019-

00287-5.

Navaratna, D., Shu, L., Jegatheesan, V., 2016. Evaluation of herbicide (persistent

pollutant) removal mechanisms through hybrid membrane bioreactors. Bioresour.

Technol. 200, 795–803. https://doi.org/10.1016/j.biortech.2015.10.041.

Nimita Jebaranjitham, J., Mageshwari, C., Saravanan, R., Mu, N., 2019. Fabrication of

amine functionalized graphene oxide – AgNPs nanocomposite with improved

dispersibility for reduction of 4-nitrophenol. Compos. Part B Eng. 171, 302–309.

https://doi.org/10.1016/j.compositesb.2019.05.018.

Nogacka, A.M., G´

omez-Martín, M., Su´

arez, A., Gonz´

alez-Bernardo, O., de Los Reyes-

Gavil´

an, C.G., Gonz´

alez, S., 2019. Xenobiotics formed during food Processing: Their

relation with the intestinal microbiota and colorectal cancer. Int. J. Mol. Sci. 20. doi:

10.3390/ijms20082051.

Oliveira, A.D. de, 2019. Polymer Nanocomposites with Different Types of Nanoller, in:

Sivasankaran, C.A.G.B.E.-S. (Ed.). IntechOpen, Rijeka, p. Ch. 6. doi:10.5772/

intechopen.81329.

Omo-Okoro, P.N., Maepa, C.E., Daso, A.P., Okonkwo, J.O., 2020. Microwave-assisted

synthesis and characterization of an agriculturally derived silver nanocomposite and

its derivatives. Waste Biomass Valor. 11 (5), 2247–2259. https://doi.org/10.1007/

s12649-018-0523-3.

Pandiarajan, A., Kamaraj, R., Vasudevan, S., Vasudevan, S., 2018. OPAC (orange peel

activated carbon) derived from waste orange peel for the adsorption of

chlorophenoxyacetic acid herbicides from water: adsorption isotherm, kinetic

modelling and thermodynamic studies. Bioresour. Technol. 261, 329–341. https://

doi.org/10.1016/j.biortech.2018.04.005.

Pang, X., Skillen, N., Gunaratne, N., Rooney, D.W., Robertson, P.K.J., 2021. Removal of

phthalates from aqueous solution by semiconductor photocatalysis: a review.

J. Hazard. Mater. 402, 123461. https://doi.org/10.1016/j.jhazmat.2020.123461.

Pang, Y.a., Zeng, G.-M., Tang, L., Zhang, Y.i., Liu, Y.-Y., Lei, X.-X., Wu, M.-S., Li, Z.,

Liu, C., 2011. Cr(VI) reduction by Pseudomonas aeruginosa immobilized in a

polyvinyl alcohol/sodium alginate matrix containing multi-walled carbon

nanotubes. Bioresour. Technol. 102 (22), 10733–10736. https://doi.org/10.1016/j.

biortech.2011.08.078.

Pariatamby, A., Kee, Y.L., 2016. Persistent organic pollutants management and

remediation. Procedia Environ. Sci. 31, 842–848. https://doi.org/10.1016/j.

proenv.2016.02.093.

Parlayici, S

¸., 2019. Alginate-coated perlite beads for the efcient removal of methylene

blue, malachite green, and methyl violet from aqueous solutions: kinetic,

thermodynamic, and equilibrium studies. J. Anal. Sci. Technol. 10 (1) https://doi.

org/10.1186/s40543-019-0165-5.

Pasinszki, T., Krebsz, M., 2020. Synthesis and application of zero-valent iron

nanoparticles in water treatment, environmental remediation, catalysis, and their

biological effects. Nanomaterials 10. doi:10.3390/nano10050917.

Pathak, V.M., Navneet, 2017. Review on the current status of polymer degradation: a

microbial approach. Bioresour. Bioprocess. 4, 15. https://doi.org/10.1186/s40643-

017-0145-9.

Phan, D.-N., 2020. Composite Nanobers: Recent Progress in Adsorptive Removal and

Photocatalytic Degradation of Dyes, in: Ngo, I.-S.K.E.-T.-D. (Ed.). IntechOpen,

Rijeka, p. Ch. 7. doi:10.5772/intechopen.91201.

Pi, Yunhong, Li, Xiyi, Xia, Qibin, Wu, Junliang, Li, Yingwei, Xiao, Jing, Li, Zhong, 2018.

Adsorptive and photocatalytic removal of Persistent Organic Pollutants (POPs) in

water by metal-organic frameworks (MOFs). Chem. Eng. J. 337, 351–371. https://

doi.org/10.1016/j.cej.2017.12.092.

Pohl, Alina, 2020. Removal of heavy metal ions from water and wastewaters by sulfur-

containing precipitation agents. Water Air Soil Pollut. 231 (10) https://doi.org/

10.1007/s11270-020-04863-w.

Qi, Hongxue, Zhao, Bingqing, Li, Lihong, Chen, Xiuling, An, Jing, Liu, Xiuping, 2020.

Heavy metal contamination and ecological risk assessment of the agricultural soil in

Shanxi Province, China. R. Soc. Open Sci. 7 (10), 200538. https://doi.org/10.1098/

rsos.200538.

Qin, Shanming, Hou, Yanping, Yuan, Guiyun, Yu, Zebin, Tu, Lingli, Yan, Yimin,

Chen, Shuo, Sun, Jiangli, Lan, Danquan, Wang, Shuangfei, 2020. Different refractory

organic substances degradation and microbial community shift in the single-

chamber bio-photoelectrochemical system. Bioresour. Technol. 307, 123176.

https://doi.org/10.1016/j.biortech.2020.123176.

Ramírez-García, R., Gohil, N., Singh, V., 2019. Chapter 21 – recent advances, challenges,

and opportunities in bioremediation of hazardous materials, in: Pandey, V.C.,

Bauddh, K.B.T.-P. of P.S. (Eds.). Elsevier, pp. 517–568. https://doi.org/https://doi.

org/10.1016/B978-0-12-813912-7.00021-1.

Rani, M., Shanker, U., 2018a. Degradation of traditional and new emerging pesticides in

water by nanomaterials: recent trends and future recommendations. Int. J. Environ.

Sci. Technol. 15 (6), 1347–1380. https://doi.org/10.1007/s13762-017-1512-y.

Rani, Manviri, Shanker, Uma, 2018b. In: Handbook of Environmental Materials

Management. Springer International Publishing, Cham, pp. 1–52. https://doi.org/

10.1007/978-3-319-58538-3_33-1.

Rashed, M. Nageeb, Eltaher, M.A., Abdou, A.N.A., 2017. Adsorption and photocatalysis

for methyl orange and Cd removal from wastewater using TiO

/sewage sludge-

based activated carbon nanocomposites. R. Soc. Open Sci. 4 (12), 170834. https://

doi.org/10.1098/rsos.170834.

Ray, Soumya Kanta, Majumder, Chanchal, Saha, Prosenjit, 2017. Functionalized reduced

graphene oxide (fRGO) for removal of fulvic acid contaminant. RSC Adv. 7 (35),

21768–21779. https://doi.org/10.1039/c7ra01069a.

RitikaKaur, M., Umar, A., Mehta, S.K., Singh, S., Kansal, S.K., Fouad, H., Alothman, O.Y.,

2018. Rapid solar-light driven superior photocatalytic degradation of methylene

blue using MoS

-ZnO heterostructure nanorods photocatalyst. Materials (Basel) 11.

https://doi.org/10.3390/ma11112254.

Rushi, A.D., 2019. Functionalized carbon nanotubes for detection of volatile organic

pollutant, in: Datta, K.P. (Ed.). IntechOpen, Rijeka, p. Ch. 6. doi:10.5772/

intechopen.85045.

Sahu, S., Sahu, U.K., Patel, R.K., 2018. Synthesis of thorium–ethanolamine

nanocomposite by the co-precipitation method and its application for Cr(vi)

removal. New J. Chem. 42, 5556–5569. https://doi.org/10.1039/C7NJ05074G.

Saif, S., Tahir, A., Asim, T., Chen, Y., Adil, S., 2019. Polymeric nanocomposites of

iron–oxide nanoparticles (IONPs) synthesized using Terminalia chebula leaf extract

for enhanced adsorption of arsenic(V) from water. Colloids and Interfaces 3, 17. doi:

10.3390/colloids3010017.

Saini, Rajesh Kumar, Bagri, Laxmi P., Bajpai, Anil Kumar, 2017. In: New Pesticides and

Soil Sensors. Elsevier, pp. 519–559. https://doi.org/10.1016/B978-0-12-804299-

1.00015-1.

Salazar, S., Guerra, D., Yutronic, N., Jara, P., 2018. Removal of aromatic chlorinated

pesticides from aqueous solution using β-cyclodextrin polymers decorated with

nanoparticles. Polymers (Basel). 10, 1038. https://doi.org/10.3390/

polym10091038.

Sharma, Ashok K., Jaiswal, Shubham K., Chaudhary, Nikhil, Sharma, Vineet K., 2017.

A novel approach for the prediction of species-specic biotransformation of

xenobiotic/drug molecules by the human gut microbiota. Sci. Rep. 7 (1) https://doi.

org/10.1038/s41598-017-10203-6.

Sharma, Brij Mohan, Bharat, Girija K., Tayal, Shresth, Nizzetto, Luca, ˇ

Cupr, Pavel,

Larssen, Thorjørn, 2014. Environment and human exposure to persistent organic

pollutants (POPs) in India: a systematic review of recent and historical data. Environ.

Int. 66, 48–64. https://doi.org/10.1016/j.envint.2014.01.022.

Shi, J., Yang, Z., Dai, H., Lu, X., Peng, L., Tan, X., Shi, L., Fahim, R., 2018. Preparation

and application of modied zeolites as adsorbents in wastewater treatment. Water

Sci. Technol. 2017, 621–635. doi:10.2166/wst.2018.249.

Siddique, Maria, Farooq, Robina, Khan, Zahid Mehmood, Khan, Zarsher, Shaukat, S.F.,

2011. Enhanced decomposition of reactive blue 19 dye in ultrasound assisted

electrochemical reactor. Ultrason. Sonochem. 18 (1), 190–196. https://doi.org/

10.1016/j.ultsonch.2010.05.004.

Silva, C.P., Jaria, G., Otero, M., Esteves, V.I., Calisto, V., 2018. Waste-based alternative

adsorbents for the remediation of pharmaceutical contaminated waters: has a step

forward already been taken? Bioresour. Technol. 250, 888–901. https://doi.org/

10.1016/j.biortech.2017.11.102.

Singh, Jagpreet, Dutta, Tanushree, Kim, Ki-Hyun, Rawat, Mohit, Samddar, Pallabi,

Kumar, Pawan, 2018. ‘Green’ synthesis of metals and their oxide nanoparticles:

applications for environmental remediation. J. Nanobiotechnol. 16 (1) https://doi.

org/10.1186/s12951-018-0408-4.

Song, Chao, Zhang, Cong, Zhang, Jingwei, Zhang, Xiaowei, 2019a. Occurrences and

patterns of residual organochlorine pesticides (OCPs) in cultured Chinese mitten

crab (Eriocheir sinensis) in China: concentrations, sources, and a human health risk

assessment. Environ. Sci. Pollut. Res. 26 (5), 4952–4960.

Song, Tianwen, Li, Shanshan, Jin, Jiafeng, Yin, Zichao, Lu, Yifeng, Bao, Mutai, Li, Yang,

2019b. Enhanced hydrolyzed polyacrylamide removal from water by an aerobic

biolm reactor-ozone reactor-aerobic biolm reactor hybrid treatment system:

performance, key enzymes and functional microorganisms. Bioresour. Technol. 291,

121811. https://doi.org/10.1016/j.biortech.2019.121811.

Sousa, Jo˜

ao C.G., Ribeiro, Ana R., Barbosa, Marta O., Pereira, M. Fernando R.,

Silva, Adri´

an M.T., 2018. A review on environmental monitoring of water organic

pollutants identied by EU guidelines. J. Hazard. Mater. 344, 146–162. https://doi.

org/10.1016/j.jhazmat.2017.09.058.

G. Karthigadevi et al.

Bioresource Technology 324 (2021) 124678

Srivastava, Varsha, Zare, Ehsan Nazarzadeh, Makvandi, Pooyan, Zheng, Xuan-qi,

Iftekhar, Sidra, Wu, Aimin, Padil, Vinod V.T., Mokhtari, Babak, Varma, Rajender S.,

Tay, Franklin R., Sillanpaa, Mika, 2020. Cytotoxic aquatic pollutants and their

removal by nanocomposite-based sorbents. Chemosphere 258, 127324. https://doi.

org/10.1016/j.chemosphere.2020.127324.

Tanne, Nathalie, Xu, Rui, Zhou, Mingyue, Zhang, Pan, Wang, Xiaomao, Wen, Xianghua,

2019. Inuence of pore size and membrane surface properties on arsenic removal by

nanoltration membranes. Front. Environ. Sci. Eng. 13 (2) https://doi.org/10.1007/

s11783-019-1105-8.

Tran, N.H., Reinhard, M., Gin, K.Y.-H., 2018. Occurrence and fate of emerging

contaminants in municipal wastewater treatment plants from different geographical

regions-a review. Water Res. 133, 182–207. https://doi.org/10.1016/j.

watres.2017.12.029.

Vaz, Bruna da Silva, Costa, Jorge Alberto Vieira, Morais, Michele Greque de, 2019.

Innovative nanober technology to improve carbon dioxide bioxation in

microalgae cultivation. Bioresour. Technol. 273, 592–598.

V´

azquez-Nú˜

nez, E., Molina-Guerrero, C.E., Pe˜

na-Castro, J.M., Fern´

andez-Luque˜

no, F., de

la Rosa-´

Alvarez, M.G., 2020. Use of nanotechnology for the bioremediation of

contaminants: a review. Processes 8, 1–17. https://doi.org/10.3390/pr8070826.

Vo, Thi Sinh, Vo, Tran Thi Bich Chau, Suk, Ji Won, Kim, Kyunghoon, 2020. Recycling

performance of graphene oxide-chitosan hybrid hydrogels for removal of cationic

and anionic dyes. Nano Convergence 7 (1). https://doi.org/10.1186/s40580-019-

0215-0.

Wang, Ning, Lv, Guochun, He, Lin, Sun, Xiaomin, 2021. New insight into

photodegradation mechanisms, kinetics and health effects of p-nitrophenol by

ozonation in polluted water. J. Hazard. Mater. 403, 123805. https://doi.org/

10.1016/j.jhazmat.2020.123805.

Wang, Yan, Sun, Changjiao, Zhao, Xiang, Cui, Bo, Zeng, Zhanghua, Wang, Anqi,

Liu, Guoqiang, Cui, Haixin, 2016. The application of nano-TiO2 photo

semiconductors in agriculture. Nanoscale Res. Lett. 11 (1) https://doi.org/10.1186/

s11671-016-1721-1.

Wei, Xiaoqian, Wang, Xin, Gao, Bin, Zou, Weixin, Dong, Lin, 2020. Facile ball-milling

synthesis of CuO/biochar nanocomposites for efcient removal of reactive red 120.

ACS Omega 5 (11), 5748–5755.

Willner, Marjorie R., Vikesland, Peter J., 2018. Nanomaterial enabled sensors for

environmental contaminants. J. Nanobiotechnol. 16 (1) https://doi.org/10.1186/

s12951-018-0419-1.

Xia, Dehua, Lo, Irene M.C., 2016. Synthesis of magnetically separable Bi2O4/Fe3O4

hybrid nanocomposites with enhanced photocatalytic removal of ibuprofen under

visible light irradiation. Water Res. 100, 393–404. https://doi.org/10.1016/j.

watres.2016.05.026.

Xiang, Yayun, Rene, Eldon R., Lun, Xiaoxiu, Ma, Weifang, 2020. Enhanced reductive

deuorination and inhibited inltration of uoroglucocorticoids in a river receiving

reclaimed water amended by nano zero-valent iron-modied biochar: performance

and mechanisms. Bioresour. Technol. 306, 123127. https://doi.org/10.1016/j.

biortech.2020.123127.

Yu, Zhengsheng, Han, Huawen, Feng, Pengya, Zhao, Shuai, Zhou, Tuoyu,

Kakade, Apurva, Kulshrestha, Saurabh, Majeed, Sabahat, Li, Xiangkai, 2020. Recent

advances in the recovery of metals from waste through biological processes.

Bioresour. Technol. 297, 122416. https://doi.org/10.1016/j.biortech.2019.122416.

Zhang, C., Lu, J., Wu, J., 2020c. One-step green preparation of magnetic seaweed

biochar/suldated FeO composite with strengthen adsorptive removal of

tetrabromobisphenol A through in situ reduction. Bioresour. Technol. 307, 123170

https://doi.org/10.1016/j.biortech.2020.123170.

Zhang, Che, Zhang, Run Z., Ma, Yong Q., Guan, Wen B., Wu, Xiao L., Liu, Xue, Li, Hong,

Du, Yan L., Pan, Can P., 2015. Preparation of cellulose/graphene composite and its

applications for triazine pesticides adsorption from water. ACS Sustain. Chem. Eng. 3

(3), 396–405.

Zhang, Quan, Wang, Ximing, Zhu, Jianqiang, Li, Zhe, Wang, Ye, 2018. Occurrence and

risk assessment of persistent organic pollutants in a branch of the Grand Canal in

Hangzhou, China. Environ. Monit. Assess. 190 (4) https://doi.org/10.1007/s10661-

018-6572-z.

Zhang, Yanzhuo, Sun, Xuedi, Bian, Wei, Peng, Jianbiao, Wan, Huilin, Zhao, Jing, 2020a.

The key role of persistent free radicals on the surface of hydrochar and pyrocarbon in

the removal of heavy metal-organic combined pollutants. Bioresour. Technol. 318,

124046. https://doi.org/10.1016/j.biortech.2020.124046.

Zhang, Yanzhuo, Yin, Muchen, Sun, Xuedi, Zhao, Jing, 2020b. Implication for adsorption

and degradation of dyes by humic acid: Light driven of environmentally persistent

free radicals to activate reactive oxygen species. Bioresour. Technol. 307, 123183.

https://doi.org/10.1016/j.biortech.2020.123183.

Zhou, Chengyun, Huang, Danlian, Xu, Piao, Zeng, Guangming, Huang, Jinhui,

Shi, Tianzhe, Lai, Cui, Zhang, Chen, Cheng, Min, Lu, Yue, Duan, Abing,

Xiong, Weiping, Zhou, Man, 2019a. Efcient visible light driven degradation of

sulfamethazine and tetracycline by salicylic acid modied polymeric carbon nitride

via charge transfer. Chem. Eng. J. 370, 1077–1086.

Zhou, H., Chen, C.-M., Diao, X., 2020. Chapter 5 – the metabolic responses of aquatic

animal exposed to POPs, in: ´

Alvarez-Mu˜

noz, D., Farr´

e, M.B.T.-E.M. (Eds.). Elsevier,

pp. 121–161. https://doi.org/https://doi.org/10.1016/B978-0-12-818196-6.00005-

Zhou, Yue, Cao, Shurui, Xi, Cunxian, Li, Xianliang, Zhang, Lei, Wang, Guomin,

Chen, Zhiqiong, 2019b. A novel Fe

/graphene oxide/citrus peel-derived bio-char

based nanocomposite with enhanced adsorption afnity and sensitivity of

ciprooxacin and sparoxacin. Bioresour. Technol. 292, 121951. https://doi.org/

10.1016/j.biortech.2019.121951.

Zur, Joanna, Pi´

nski, Artur, Marchlewicz, Ariel, Hupert-Kocurek, Katarzyna,

Wojcieszy´

nska, Danuta, Guzik, Urszula, 2018. Organic micropollutants paracetamol

and ibuprofen—toxicity, biodegradation, and genetic background of their utilization

by bacteria. Environ. Sci. Pollut. Res. 25 (22), 21498–21524. https://doi.org/

10.1007/s11356-018-2517-x.

G. Karthigadevi et al.

ResearchGate has not been able to resolve any citations for this publication.

Semiconductor based photocatalysts for detoxification of emerging pharmaceutical pollutants from aquatic systems: A critical review

Article

Full-text available

Nov 2020

The presence of emerging pharmaceutical pollutants at low concentration levels in the surface and ground water has caused a potential threat to the marine and human lives. The emerging pharmaceutical pollutants generally include analgesics and anti-inflammatories, lipid-lowering drugs, antiepileptics, antibiotics, and β-blockers compounds. In recent years, various processes have been developed and advanced oxidation process is the most effective for decontamination of emerging pharmaceutical pollutants till date. Semiconductor based photocatalysis technology has recently received a great interest for the removal of new emerging pharmaceutical pollutants. This review article highlights the removal of emerging pharmaceutical pollutants especially through photocatalysis as well as recent progress using different nanostructures. Additional focus has been given over fundamental key dynamics processes of nanomaterials and degradation pathways of emerging pharmaceutical pollutants. Finally, this review concludes with the perspectives and outlook over future developments in photocatalysis technology for the degradation of emerging pharmaceutical pollutants leading to a solution for real-world in near future.

Heavy metal contamination and ecological risk assessment of the agricultural soil in Shanxi Province, China

Article

Full-text available

Oct 2020

To assess contamination levels and ecological risks of heavy metals in agricultural soil from Shanxi Province of China, a total of 33 samples in the surface soil were collected from 11 cities in Shanxi. The soil samples were digested by a mixed acid of nitric acid and hydrofluoric acid on a microwave digestion system, then the levels of eight heavy metals were analysed using an inductively coupled plasma mass spectrometer. The pollution levels of soil heavy metals were evaluated using a geo-accumulation index and their ecological risks were assessed using risk index calculated by Hakanson's method. As a result, the average concentrations of the heavy metals As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were 12.9 ± 4.8, 0.35 ± 0.23, 43 ± 14, 27 ± 19, 0.25 ± 0.14, 21.7 ± 5.7, 17 ± 13 and 89 ± 53 mg kg ⁻¹ , respectively. By comparison to the Chinese soil environmental quality (GB15618-2018), only 9% of Cd samples and 3% of Cu samples exceeded their corresponding screening criteria. Subsequently, the results of geo-accumulation indices suggested that Shanxi's soil suffered from moderate to heavy contamination posed by Cd and Hg, and risk indices exhibited a similar trend that Cd and Hg were the main contributors for considerable to very high ecological risk. Finally, the analysis of variance indicated that the mean levels of Cd significantly occurred at Yuncheng areas among the 11 cities ( n = 3, p < 0.05), but Hg concentrations did not have significantly statistical differences. This study demonstrated that metals Cd and Hg had higher levels and ecological risks for agricultural soil in Shanxi, especially, Yuncheng City suffered from heavy Cd contamination. The findings of the present study will provide basic information on management and control of the agricultural soil contamination in Shanxi Province, China.

Removal of Heavy Metal Ions from Water and Wastewaters by Sulfur-Containing Precipitation Agents

Article

Full-text available

Sep 2020
WATER AIR SOIL POLL

Alina Pohl

Restrictive requirements for maximum concentrations of metals introduced into the environment lead to search for effective methods of their removal. Chemical precipitation using hydroxides or sulfides is one of the most commonly used methods for removing metals from water and wastewater. The process is simple and inexpensive. However, during metal hydroxide precipitation , large amounts of solids are formed. As a result, metal hydroxide is getting amphoteric and it can go back into the solution. On the other hand, use of sulfides is characterized by lower solubility compared with that of metal hydroxides, so a higher degree of metal reduction can be achieved in a shorter time. Disadvantages of that process are very low solubility of metal sulfides, highly sensitive process to the dosing of the precipitation agent, and the risks of emission of toxic hydrogen sulfide. All these restrictions forced to search for new and effective precipitants. Potassium/sodium thiocarbonate (STC) and 2,4,6-trimercaptotiazine (TMT) are widely used. Dithio-carbamate (DTC) compounds are also used, e.g., sodium dimethyldithiocarbamate (SDTC), and ligands for permanent metal binding, e.g., 1,3-benzenediamidoethanethiol (BDETH 2), 2,6-pyridinediamidoethanethiol (PyDET), a pyridine-based thiol ligand (DTPY) or ligands with open chains containing many sulfur atoms, using of a tetrahe-dral bonding arrangement around a central metal atom. The possibility of improving the efficiency of metal precipitation is obtained by using a higher dose of precipitating agent. However, toxic byproducts are often produced. It is required that the precipitation agents not only effectively remove metal ions from the solution but also effectively bind with dyes or metal complexes.

Synthesis of the ZnTiO3/TiO2 Nanocomposite Supported in Ecuadorian Clays for the Adsorption and Photocatalytic Removal of Methylene Blue Dye

Article

Full-text available

Sep 2020

Currently, the study of semiconductor materials is very promising for the photocatalytic remediation of hazardous organic substances present in the air and water. Various semiconductors have been investigated in this interesting photo-assisted methodology, among them metal oxides such as ZnO, TiO2 and their derivatives. In this study, ZnTiO3/TiO2 was synthesized by the sol-gel method using Ti(OC3H7)4 and Zn(CH3COO)2 · 2H2O as reagents. The role of several conditions such as synthesis temperature and TiO2:ZnO proportion on the morphology and purity of compounds obtained was studied, and the suitable conditions for the synthesis of photocatalysts were determined. Various techniques were used to conduct a systematic investigation on the structural, morphological, and photocatalytic properties of ZnTiO3/TiO2. Scanning Electron Microscopy (SEM) images show that ZnTiO3/TiO2 have a typical particle size of approximately 100 nm with a quasi-spherical shape. The adsorption and photocatalytic activity were investigated by the decolorization of Methylene Blue (MB) as an organic contaminant under UV irradiation both in TiO2 and ZnTiO3/TiO2 supported over some Ecuadorian clays. The materials evaluated were prepared in the shape of 0.2 cm (diameter) and 1.0 cm (length) cylindrical extrudates. The degradation percentage of MB obtained was 85% approximately after 150 min of irradiation. The results obtained allow us to conclude that these synthesized materials can be used as adsorbents and photocatalysts.

Novel TiO2/GO/CuFe2O4 nanocomposite: a magnetic, reusable and visible-light-driven photocatalyst for efficient photocatalytic removal of chlorinated pesticides from wastewater

Article

Full-text available

Sep 2020

A TiO2/GO/CuFe2O4 heterostructure photocatalyst is fabricated by a simple and low-cost ball-milling pathway for enhancing the photocatalytic degradation of chlorinated pesticides under UV light irradiation. Based on the advantages of graphene oxide, TiO2, and CuFe2O4, the nanocomposite exhibited visible light absorption, magnetic properties, and adsorption capacity. Integrated analyses using XRD, SEM, TEM, and UV-visible techniques demonstrated that the nanocomposite exhibited a well defined crystalline phase, sizes of 10–15 nm, and evincing a visible light absorption feature with an optical bandgap energy of 2.4 eV. The photocatalytic degradations of 17 different chlorinated pesticides (persistent organic pollutants) were assayed using the prepared photocatalyst. The photocatalytic activity of the nanocomposite generated almost 96.5% photocatalytic removal efficiency of typical pesticide DDE from water under UV irradiation. The superior photocatalytic performance was exhibited by the TiO2/GO/CuFeO4 catalyst owing to its high adsorption performance and separation efficiency of photo generated carriers. The photocatalyst was examined in 5 cycles for treating uncolored pesticides with purposeful separation using an external magnetic field.

Emerging nano-structured innovative materials as adsorbents in wastewater treatment

Article

Jan 2021

Water supply around the globe is struggling to meet the rapidly increasing demand by the population, drastic changes in climate and degrading water quality. Even though, many large-scale methods are employed for wastewater treatment they display several negative impacts owing to the presence of pollutants. Technological innovation is required for integrated water management with different groups of nanomaterials for the removal of toxic metal ions, microbial disease, organic and inorganic solutes. The method of manipulating atoms on a nanoscale is nanotechnology. Nanomembranes are used in nanotechnology to soften water and eliminate physical, chemical and biological pollutants. The present review concentrates on various nanotechnological approaches in wastewater remedy, mechanisms involved to promote implementation, benefits and limitations in comparison with current processes, properties, barriers and commercialization research needs. Also the review identifies opportunities for further exploiting the exclusive features for green water management by following the advances in nanotechnology.

New insight into photodegradation mechanisms, kinetics and health effects of p-nitrophenol by ozonation in polluted water

Article

Feb 2021
J HAZARD MATER

P-nitrophenol (p-NP) is a recalcitrant organic compound attracted great environmental attention, but its degradation mechanism is indeterminacy, which challenges its treatment, migration, transformation and ecological impact in the environment. In the present study, the aqueous-phase decomposition process of p-NP initiated by O3 has been investigated by a theoretical calculation method. The detailed possible reaction pathways for the oxidative degradation of p-NP by ozone have been proposed. The chemical reaction thermodynamics results show that the reaction barriers of all ozone-initiated pathways are below 15 kcal·mol⁻¹, indicating that ozone can completely initiate the oxidation of p-NP under natural conditions. However, the kinetic results show that the initiation reaction of p-NP by ozone alone is relatively slow compared to the reaction by OH. Interestingly, under ultraviolet (UV) radiation, the dissolved ozone interacts with water and produces two active radicals: OH and HO2. The reaction rate of p-NP initiated with OH is much higher than that with ozone, implying that the OH produced in the photochemical process can improve the removal efficiency of p-NP. The intermediates generated in the ozone-initiated reaction have been found to decompose into small molecule organic acids, aldehydes and ketones. The potential carcinogenicities and teratogenicities of the transformation products have also been studied, and some of them still have carcinogenic activity, which deserve further attention. In addition, to our knowledge, this may be the first computational chemistry study on the degradation of p-NP initiated by HO2. All the results provide a new fundamental understanding for the migration and transformation of p-NP in water environment, and indicate that further assessment is needed for the impact of p-NP and especially its transformation products on the ecological environment in a significant way.

The key role of persistent free radicals on the surface of hydrochar and pyrocarbon in the removal of heavy metal-organic combined pollutants

Article

Aug 2020
BIORESOURCE TECHNOL

We show that persistent free radicals (PFRs) on the surface of biochar can produce hydroxyl radicals (•OH) by catalyzing H2O2 to facilitate the removal of the combined pollutant BPA-Cr(VI). Microstructure characterization showed that the structures of pyrocarbon and hydrochar were significantly different when prepared at different temperatures. As the preparation temperature and preparation time for biochar increased, the concentration of PFRs first increased and then decreased. When biochar, PFRs, and H2O2 were present in the same solution, the single pollutants BPA and Cr(VI) as well as the combined pollutant BPA-Cr(VI) could be removed effectively, with removal rates greater than 90%. However, when PFRs, BPA, H2O2, and Cr(VI) were present in the same solution, Cr(VI) competed with H2O2 for electrons and promoted the removal of BPA. The results of this study could be applied to sludge recycling and be used to develop approaches to catalytically degrade combined pollutants.

Enhanced reductive defluorination and inhibited infiltration of fluoroglucocorticoids in a river receiving reclaimed water amended by nano zero-valent iron-modified biochar: Performance and mechanisms

Article

Mar 2020
BIORESOURCE TECHNOL

The main aim of this study was to investigate the effect of a nano zero-valent iron-modified biochar-amended composite riverbed (nZVI@BC-R) on inhibited infiltration and enhanced biodegradation of fluoroglucocorticoids (FGCs) in a river receiving reclaimed water. The results demonstrated that the removal efficiency of triamci-nolone acetonide (TA), a representative FGC, increased from 38.40% and 77.91% to 91.60% in the nZVI@BC-R compared with that of a natural soil riverbed (S-R) and biochar-amended soil riverbed (BC-R). The main removal mechanism was attributed to adsorption and biodegradation, of which the contribution rates were 32.2% and 59.4% in nZVI@BC-R, 18.9% and 19.5% in S-R, and 24.4% and 53.5% in BC-R, respectively. The removal process could be described by a two-compartment, first-order dynamic model with decay rate constants for adsorption and biodegradation of 4.02700, 22.44400, and 29.07300 d −1 and 0.00286, 0.01562, and 0.03484 d −1 in the S-R, BC-R and nZVI@BC-R, respectively. The mechanism of defluorination accounted for 42.2% of biodegradation in the nZVI@BC-R, which was accompanied by side-chain rupture, oxidation, and ring opening. Functional microbes with iron oxidizing ability and reductive dehalogenating genera, namely Pseudoxanthomonas, Pedobacter, and Bosea, contributed to the high removal rate of TA, particularly in the nZVI@ BC-R. Overall, the nZVI@BC-R provided an effective method to inhibit glucocorticoids infiltration into groundwater.

Removal of Phthalates from Aqueous Solution by Semiconductor Photocatalysis: A review

Article

Jul 2020
J HAZARD MATER

Abstrac While phthalate esters are commonly used as plasticizers to improve the flexibility and workability of polymeric materials, their presence and detection in various environments has become a significant concern. Phthalate esters are known to have endocrine-disrupting effects, which affects reproductive health and physical development. As a result, there is now increased focus and urgency to develop effective and energy efficient technologies capable of removing these harmful compounds from the environment. This review explores the use of semiconductor photocatalysis as an efficient and promising solution towards achieving removal and degradation of phthalate esters. A comprehensive review of photocatalysts reported in the literature demonstrates the range of materials including commercial TiO2, solar activated catalysts and composite materials capable of enhancing adsorption and degradation. The degradation pathways and kinetics are also considered to provide the reader with an insight into the photocatalytic mechanism of removal. In addition, through the use of two key platforms (the technology readiness level scale and electrical energy per order), the crucial parameters associated with advancing photocatalysis for phthalate ester removal are discussed. These include enhanced surface interaction, catalyst platform development, improved light delivery systems and overall system energy requirements with a view towards pilot scale and industrial deployment.

Chemico-nanotreatment methods for the removal of persistent organic pollutants and xenobiotics in water -A review

Figures

Recommended publications

Occurrence and distribution of persistent organic pollutants in water of Chinese lakes and reservoir...

Suspended particle-associated PAHs in the open Eastern Mediterranean Sea: Occurrence, sources and pr...

Persistent organic pollutants (POPs) at Ross Sea (Antarctica) and through Circumpolar Deep Water

Electrochemical Advanced Oxidation Processes for removing toxic/persistent organic pollutants from w...