Table 5 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
Source publication
The removal of heavy metals from industrial waste streams has become one of the most important applica-tions in wastewater treatment in terms of protecting public health and environment. The recovery of metals present in the industrial effluents by adsorption onto natural materials constitutes a technological option in-creasingly studied throughout...
Context in source publication
Similar publications
Spent coffee grounds are a waste generated in large amounts by the food industry producing instant coffee. While it is used as animal feed, mostly spent coffee grounds are burned. In this study, The spent coffee grounds were modified to be magnetic in order to remove cadmium (II) ion. The magnetic solids are easy to separate from water with a magne...
The remediation of cadmium and lead ions from their respective aqueous solutions was carried out with the use of metal-organic frameworks (MOFs) developed from copper and zinc with benzene-1,4-dicarboxylic acid (BDC). The experimental adsorption process was done in batches to determine the equilibrium characteristics, thermodynamics and kinetics of...
Lignocellulosic fibers were subjected to an acid and alkaline pre-treatment and used as adsorbent of copper, cadmium, lead and nickel metal ions from aqueous phase. Adsorption process was carried out in batch conditions and the effects of alkaline treatment were investigated. Homogeneous diffusion of a particle model was used to predict the adsorpt...
A novel adsorbent was synthesized through the entrapment of ball-milled biochar in Ca-alginate beads for the removal of aqueous Cd(II). Batch adsorption experiments were conducted to compare Cd(II) adsorption characteristics of ball-milled biochar (BMB), Ca-alginate (CA), and Ca-alginate entrapped ball-milled biochar (CA-BMB). All the tested adsorb...
Pollution of aquatic environments with heavy metals from natural water is a serious problem because of the toxicity of heavy metals to humans, fish, and other live organisms. Cheap and environmentally friendly methods for removing heavy metals from water are therefore needed. Algae have emerged as a promising biosorbent to bioextract heavy metal io...
Citations
... Tablo 5'te bu çalışmada elde edilen adsorpsiyon kapasitesi, literatürdeki diğer killer ile kıyaslanmıştır: Tablo 5. Farklı absorplayıcılarına adsorpsiyon kapasiteleri (Khalfa and Bagane, 2011) Farklı killere ait adsorpsiyon kapasitelerinin değerlerinin farklı olma nedenleri adsorplayıcının cinsi (yüzey alanı, gözenek sayısı ve hacmi, aktif bölgelerin çokluğu vb.) adsorplanan maddenin cinsi (pozif, negatif veya nötr olması, yükseltgenme basamağı) ve bu iki madde arasındaki afinite, çalışma sıcaklığı, çalkalayıcı hızı, ortamdaki diğer maddelerin interferansı ve kullanılan adsorpsiyon modelinin türü gibi pek çok faktör adsorplayıcı kapasitesi üzerinde etkili olabilmektedir. ...
One of the most significant environmental pollutions is water pollution. Water pollution, which is a problem all over the world, has been increasing recently due to unconscious and contemptuous water usage and will inevitably lead to water wars. In this context, it has become a necessity to reduce water pollution and raise awareness among people. One of the effective and inexpensive methods among the studies on this subject is adsorption. The main purpose of this study is to remove Ni (II) ions from aqueous solutions. For this, mixed type clay was used as adsorber. Clay obtained from the Koçpınar town of Siirt is preferred because it can be obtained easily and it’s cost is low. To determine the characterization of the clay, SEM, XRD XRF and FT-IR analyzes were performed. The results obtained from these analyzes showed that the clay was of mixed type. Pseudo-second-order kinetic models are widely applied to data from most adsorption kinetic studies to describe the adsorption mechanism of adsorbate on adsorbent. In this research, 6 different types of pseudo-second order kinetic equations were applied to values at 298 K temperature. The obtained data were applied to six types of linear equations. R2, K2 and qm values were calculated by creating graphs in the light of abovementioned data. As a result of the obtained data, it was understood that adsorption kinetics comply with type 6 equation at most.
... Effect of time on the adsorption of metal ions was studied at 20 °C as described by Khalfa et al. (2011Khalfa et al. ( , 2016. Briefly, 500 mL of the desired metal solution was shaken with 1 g/L of either NC or AC clay sample at 200 rpm; agitation time ranged between 5 and 240 min. ...
... The quantity of heavy metal removed has been calculated as the difference between initial and equilibrium concentrations (Khalfa and Bagane 2011). ...
The present study has been carried for the potential use of raw clay from Gabes district (southern Tunisia) in wastewater treatment. A representative clay sample was collected from the outcropping feature of the Aidoudi area to the west of Gabes city; it followed a simple treatment to enhance its physico-chemical properties. Adsorption experiments were carried out by using a simple batch technique in single and multi-element solution (Pb2+, Cd2+, Cu2+ and Zn2+). The obtained results were fitted to different adsorption models, including extended and modified Langmuir, extended Freundlich and modified Redlish-Peterson. Our results indicated that the collected clay sample is mainly a smectite with high amounts of silica, alumina and iron. Adsorptive removal of single elements revealed encouraging efficiencies for most of the studied metals, reaching nearly 100%. Our results also indicated that lead removal reached 26.78 mg/g and 45.94 mg/g for natural and activated clay samples, respectively. Competitive adsorption showed strong dependence on the initial concentration and the metal properties, with preferential removal of lead that reached 41.71 mg/g in binary systems. In most of mixed systems, metal removal substantially decreased in the presence of competing ions. It showed preferential removal of lead over other metals, regardless of the studied mixture. Further, the use of smectitic clay from southern Tunisia showed a good potential for metal ions removal in single, binary, ternary and quaternary systems from aqueous solutions. Thus, it could be turned out to a viable material for the treatment of metal loaded waters.
... Adsorption of the metal cations, (Pb(II), Cd(II), Co(II), and Ni(II)), on WTRs depends on pH, with an increasing pH of the solution the removal efficiency was higher [41,69,73,89]. It might be explained by the fact that metal ions form complexes with acidic functional groups in the sorbent [92]. In case of decreasing pH, protons compete with metal ions for the binding sites on the WTRs surface and the protons decrease the negative charges [73,79]. ...
Heavy metal contamination is one of the most important environmental issues. Therefore, appropriate steps need to be taken to reduce heavy metals and metalloids in water to acceptable levels. Several treatment methods have been developed recently to adsorb these pollutants. This paper reviews the ability of residuals generated as a by-product from the water treatment plants to adsorb heavy metals and metalloids from water. Water treatment residuals have great sorption capacities due to their large specific surface area and chemical composition. Sorption capacity is also affected by sorption conditions. A survey of the literature shows that water treatment residuals may be a suitable material for developing an efficient adsorbent for the removal of heavy metals and metalloids from water.
... Fig. 5 shows the pH effect on the removal of Cd(II) using TSS. The removal of cadmium ions increased with increasing pH value; for instance, at low values of pH, the percentage removal is low which is due to the protons competition with metal ion for the binding sites on the TSS surface meaning an important electrostatic repulsion was promoted; at this stage, protons also decrease the negative charges by association of the functional group with protons [33]. As the pH increases, the removal percentage increases as well; this can be associated with the Freundlich ln(Q e ) = lnK F + 1/n ln(C e ) (4) K F = adsorption capacity; n = intensity of adsorption; 1/n = 0 irreversible, 1/n > 1 unfavorable, 0 < 1/n < 1 favorable Table 3 Kinetic models used to fit the experimental data ...
Low-cost adsorbent based on sewage sludge was studied on the adsorption of cadmium ion Cd(II)
in a batch system. The raw sewage sludge was treated using sulfuric acid and then heated at
300°C. The as-obtained material was characterized by Thermogravimetric analyses (TGA),
Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and
Brunauer–Emmett–Teller (BET) surface area. The treated sewage sludge (TSS) exhibits a higher
surface area than the raw material due to the activation process. Some parameters such as
adsorbent dose, solution pH, initial concentration and contact time were investigated in the batch
system to study the optimum adsorption condition of the adsorbent. The kinetic study showed that
the adsorption is well described by the pseudo-second order kinetic model, while sorption
isotherms gave better fit for the Langmuir model yielding an adsorption capacity of the 56.2 mg/g.
Moreover, adsorption mechanism was proposed on the basis of infrared spectroscopy and
elemental analyses after adsorption.
... Thus, we adopted Langmuir isotherm for the description of the removal process. Maximum adsorption capacity of Cd(II) was 23.593 mg/g, which was higher than that of carbon nanotubes (14.45 mg/g [33]), porous resins (3.51 mg/g [14]), mesoporous silica materials (18.25 mg/g [15]), clay materials such as kaolinite (6.80 mg/g [34]), vermiculite (20.7 mg/g [35]) but lower than smectitic clay (26.7 mg/g [36]) and activated sericite (39.83 mg/g [37]). ...
Adsorption and photo-Fenton processes were used as handy tools to ascertain the capability of natural clays to remove cadmium (Cd) and 2-chlorophenol (2-CP) from aqueous solution. Natural Fe-rich clay collected from Tejera-Esghira in Medenine area, south Tunisia, was used as a catalyst in the heterogeneous photo-Fenton oxidation of 2-CP in aqueous solution. Clay samples were acid activated to improve their adsorptive capacity for the removal of Cd. Experimental results indicated that the adsorption of Cd ions onto natural red clay of Tejera-Esghira followed the pseudo-second-order kinetic model. Langmuir model was found to describe the equilibrium data with the calculated maximum adsorp-tion capacity of 23.59 mg g À1 for acid-activated clay. Photo-Fenton experiments proved high activity of the natural clay catalyst, which was able to completely degrade the phenol present in the treated solution after 30 min and in the presence of ultraviolet light C (UV-C). Total organic carbon and gas chromatography analysis confirmed a 2-CP degradation mechanism toward an almost complete mineralization of the organic compound.
... Thus, we adopted Langmuir isotherm for the description of the removal process. Maximum adsorption capacity of Cd(II) was 23.593 mg/g, which was higher than that of carbon nanotubes (14.45 mg/g [33]), porous resins (3.51 mg/g [14]), mesoporous silica materials (18.25 mg/g [15]), clay materials such as kaolinite (6.80 mg/g [34]), vermiculite (20.7 mg/g [35]) but lower than smectitic clay (26.7 mg/g [36]) and activated sericite (39.83 mg/g [37]). ...
... Mariadas et.al., 2012) Montmorillonite 32.7 (i.e. Khalfa, 2011) Fly ash 198.2 (i.e. Kadirvelu, 2003) Peanut hull carbon 89.4 (i.e. ...
Abstract: This project focuses on the synthesis of physically modified chitosan; chitosan
beads and determination of the effect of contact time, beads dosage and bead size on Cd(II)
adsorption capacity of chitosan beads from aqueous solutions at pH 7 and at temperature of
30±2 ̊ C. Further, the visual examinations of chitosan beads were conducted using SEM
analysis. Isotherm experiments and kinetic studies were done to find out the maximum
adsorption capacity and the order of the reaction respectively. According to the results
obtained, the optimal performance of chitosan beads were achieved when initial Cd(II) ion
concentration of the sample was 50 mg L-1 with chitosan bead diameter (1.11±0.02) mm,
contact time of 150 minutes and chitosan bead dosage 0.40 mg. The isotherm experimental
data at 30 ̊ C were satisfactorily fitted to Langmuir adsorption isotherm with R2 value of
0.993. The maximum adsorption capacity value; Langmuir constant, qo obtained for
adsorption of Cd(II) onto chitosan beads was 62.5 mg g-1 which is considerably a higher
value compared to qo values for adsorption of Cd(II) onto various other biomass types
reported in the literature. The kinetic data were fitted with the pseudo second order model
with R2 values of 0.992 and 0.988 for initial Cd(II) concentrations of 30 mg L-1 and
50 mg L-1 respectively. Therefore, the results revealed that the concentration of Cd(II) and
amount of chitosan beads both may involve in the rate determining step and the adsorption
process may be chemisorption.
... These two properties make clay nanoparticles (CNP) to be strong adsorbents for metal cations, [9]. Khalfa and Bagane [11] reported to have removed cadmium from aqueous solution using natural and activated clays and Darban [12] synthesized nano-alumina powder with high surface area of 201.53 m 2 /g and small particle size of 22-36 nm from impure kaolin and used it for removal of arsenite from aqueous solutions, where he achieved an adsorption recovery of 97.65% from an initial arsenite concentration of 10 mg/l. Clay is highly hydrophilic and is converted to hydrophobic nature by functionalizing with organo modifiers which are quaternary ammonium salts, that possess a permanent positive charge. ...
The importance of water purification especially removal of both organic and inorganic contaminants cannot be overemphasized, hence the need to develop water purification materials that are cheap, easily available and efficient. This would ensure realization of the Clean Water and Sanitation Sustainable Development Goal (SDGs). The current study involves isolation of clay nanoparticles (CNP) and functionalizing them with Cetylpyridinium Chloride (CPC) and Tetradecyltrimethylammonium Bromide (TTAB) to form C-CPC and C-TTAB respectively, so as to increase efficiency in removal of lead, cadmium and pentachlorophenol (PCP) through batch process. Clay was acquired locally, purified and CNP isolated by sedimentation and centrifugation. The CNP, C-CPC and C-TTAB were characterized using Fourier Transform Infra-Red (FTIR) spectroscopy, X-Ray Diffractometry (XRD), Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM). HRTEM revealed a particle size of 12-15 nm for the three adsorbents. CNP had a lead removal efficiency of 88% at initial concentration of 80 ppm and 94% for Cadmium at initial concentration of 50 ppm, while C-CPC and C-TTAB had lead removal efficiencies of 98%. For cadmium removal, C-CPC and C-TTAB had 98.2% and 98.6% efficiencies respectively. In pentachlorophenol (PCP) adsorption, CNP, C-CPC and C-TTAB had removal efficiencies of 85.6%, 87.7% and 84.6% respectively. The findings suggest that isolation of CNP and consequent modification with the surfactants increases adsorption efficiency of clay against the water pollutants.
... Fig. 4 shows the in- fluence of pH on the adsorption of 10 mg/l cadmium ion in water, where both of the adsorbents showed the similar result. The removal efficiency of cadmium ion increased with pH of the solution because cadmium ion formed a complex with some acidic functional groups in the adsorbent ( Khalfa and Bagane, 2011). Adsorption of metal cation on adsorbent de- pends upon the nature of adsorbent surface and the distribution of metal species also depends on the pH of the solution. ...
... The ad- sorption capacity of cadmium ion for high initial cadmium ion concentration was higher than for low initial cadmium ion concentra- tion of the solution at the same time. This result is important because the time required to reach equilibrium is one of the considerations for the application of economical wastewater treatment plant ( Khalfa and Bagane, 2011;Rao et al., 2006). ...
... Humic acids play an important role in the process of adsorption of Cd 2+ because it contains some functional groups ( Riffaldi and Minzi, 1975;Arias et al., 2002;Khalfa and Bagane, 2011). In the presence of humic acid, the sludge might behave more like a chelating ion- exchanger for heavy metal ions than as a simple inorganic ion exchang- er ( Hizal and Apak, 2006). ...
A low cost adsorbent based on sludge of drinking water treatment plant (DWTP), solid waste by-product of sedimentation process in the DWTP, was studied for adsorption of cadmium ion in water. Some parameters such as dose of the adsorbent, pH of solution, and shaking time were investigated in the batch system in order to know the optimum condition and adsorption ability of the adsorbent. Artificial sludge was prepared by following the process of DWTP and the effect of humic acid extracted from the DWTP sludge was examined in order to clarify the key component and adsorption capacity of the adsorbent. This study found that humic acid and iron oxide were the key components of the adsorbent material for adsorption of cadmium ion in water. The Langmuir isotherm adsorption model was fit and the adsorption capacity of the adsorbent based on sludge of Miyamchi and Nishino DWTP for Cd(II) was 5.3 and 9.2 mg/g, respectively. The finding of this study is important for further development of a low cost adsorbent material in the near future.
The recycling of untreated dry biosolids, as costless biodegradable adsorbent for the removal of cadmium from aqueous phase was characterized. The adsorption of cadmium was reported to depend on initial pH, adsorbent dose, agitation time, and initial Cd concentration. The results of the batch experiments revealed that the maximum adsorption capacity of the untreated dry biosolids was 39.22 mg g-1 under optimum operating conditions (i.e. pH: 5, adsorbent dose: 2 g l-1, contact time: 16h). Adsorption reaches equilibrium after 16h, which can be attributed to both external surface adsorption (R2 = 0.86) and intraparticle diffusion (R2 = 0.98). The Langmuir isotherm model best described cadmium adsorption (R2 = 0.99) and the pseudo-second-order kinetic model was obeyed, suggesting that the mechanism involved was chemisorption. Biodegradability would make the recovery of adsorbed Cd an environmentally friendly process. Comparing the obtained findings with the related published results, it can be concluded that treating biosolids might be an unnecessary and costly procedure for recycling biosolids as an adsorbent for cadmium.
