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Heavy-metals water pollution is without doubt a significant environmental problem in the global context. These non-degradable chemical pollutants may be the cause of serious ecological and health issues, due to their ability of penetration and accumulation throughout the food chain exposing humans to slow but certain poisoning. In order to alleviat...
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... (C5H8O4)n with n represents the number of glucose groups and called degree of polymerization (DP) is a long linear homopolymer composed of glucose units (as shown in Figure 2) with β-(1,4) glycosidic linkage [22,64], it mainly contains carbon (44.44%), hydrogen (6.17%) and oxygen (49.39%) [60]. The DP of cellulose ranges from hundreds to tens of thousands and even higher. ...
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Water pollution with heavy metals due to discharge of untreated domestic wastes and surface runoff to the rivers is a major threat for human health that consumes vegetables grown with the polluted river. The present study aimed to examine the contamination of heavy metals through the health risk assessment via the consumption of spinach vegetable g...
The water pollution impacts on water quality degradation and the population of E. crassipes covered almost 30% in Batujai Reservoir area. Among pollutants, heavy metals are one that should be highlighted because they are non-biodegradable, accumulate in the environment, and has been considered as a vital threat to the human health via the food chai...
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... In addition to a range of extractives, the three primary constituents of sawdust, often known as wood waste, and are cellulose (45-50%), lignin (23-30%), and hemicellulose (20-30%). Since sawdust is a common natural adsorbent and one of the least expensive remediation techniques, it is typically used to remove pollutants from soil or water [36] This is also evidenced by the surface area of sawdust so that there is a chance for contaminants to be trapped. The surface area of sawdust was (0.969 m 2 /g), around 1.39 times that of raw sawdust. ...
Waste from the broiler and layer farming industry with a closed-house system continues to increase without optimizing waste utilization and harms the environment. Potential chicken litter waste from the chicken farming industry in West Sumatra is 5 tons per harvest (40 days) from a chicken livestock capacity of 100,000 chickens. This research aims to assess the potential and utilization and study the biochemistry of chicken manure waste in closed-house systems as biosorbents and fertilizers through amelioration technology. Closed-house chicken coop bedding waste (CHCCW) in the form of sawdust has functional groups such as carboxyl that can absorb cations because it can increase the negative charge in the soil so that it can be utilized by plants. In addition, the CHCCW can also absorb cations (pollutants). Chemical characteristics from the analysis results prove the ability of the CHCCW. Chicken litter waste has chemical characteristics that have the potential as a biosorbent and are valid as fertilizer, which has a proximate composition (moisture 4.26%; volatile matter 74.20%; ash 6.78% and fixed carbon 14.76%); pH (pH H2O 8.37 and pH PZC 7.37); electrical conductivity (EC) >2 dS m-1 and cation exchange capacity (CEC) 182.67 Cmol(+)kg-1. The nutrient composition of chicken manure waste in closed-house systems has macro nutrients (6.88% C; 0.06% N; 5.89% P; 34.89% K; 36.28% Ca; 5.76% S) and micronutrients (2.49% Fe; 1.39% Mn; 1.22% Zn; 1.01% Cu; and 5.15% Cl). Chicken manure waste in closed-house systems also has functional groups such as O-H, N-H, C-H, C-OH, C=C, C=O, C-O-C, Si-O, and O-CH3, which play an active role in the absorption of pollutants and nutrients in the soil.
... Sawdust as industrial and agricultural waste finds many applications in vast areas [33]. Sawdust or wood waste mainly consists of cellulose (45-50%), lignin (23-30%), hemicellulose (20-30%), and other substances (acids, soluble sugar, resins, wax, and oil) [34,35]. Sawdust has good mechanical stability, high porosity and water-holding capacity, and sufficiently high carbon content and calorific value [36]. ...
Biomass is a promising resource for the production of renewable energy, liquid fuels, and chemicals. Microwave pyrolysis is one of the directions of multifunctional conversion of raw materials. In the present work, the effect of microwave power on the characteristics of sawdust pyrolysis is studied. With an increase in power, the maximum yield of combustible gases increased, and a large proportion of the total pyrolysis time included the useful time for the release of gases. An increase in power affected the yield of individual gases non-linearly and on a different scale. The average yield of CO and CO2 remained practically unchanged when the microwave power was increased from 840 to 1760 W. However, with a further increase in power to 2200 W, there was a significant increase in the average yield of CO and CO2 (2.5 and 1.4 times, respectively). An increase in power by 2.6 times contributed to an increase in the average yield of CH4 by 5 times and H2 by 3.8 times. The increased power of microwaves contributed to the degassing of wood and intensification of secondary pyrolysis reactions, which resulted in a decrease in the mass of the solid residue by 5.3 times and a decrease in the liquid product yield by 2.7 times. A comprehensive analysis using MCDA showed that an increase in energy costs with an increase in microwave power is integrally compensated by an improvement in pyrolysis performance. So, when the power was varied from 840 W to 2200 W, the pyrolysis efficiency indicator increased by 1.3–2.2 times, considering the growth in energy consumption.
... The sensitivity of CPE can be further increased by using modifying agents, such as titanium dioxide, zirconium oxide, etc., which may be physically or electronically coated onto the CPE. Studies have proven that lignocellulosic wastes are ideal materials for heavy metal ion removal due to their high adsorption capacity, selectivity, large surface area, high purity, and porosity [14,15]. ...
Heavy metals (HM) have gained significant attention in terms of regular monitoring and detection owing to their toxicity, non-biodegradability, and persistence. Current techniques for detecting HM are expensive, cumbersome, and require sophisticated instruments and skilled labor. Hence, developing cheap, rapid, energy-efficient, and accurate sensors is imperative and electrochemical techniques have emerged as promising tools. The current study involves the fabrication of an electrochemical sensor for the concurrent detection of lead (Pb2+) and cadmium (Cd2+) ions using modified carbon paste electrodes (mCPE). Activated carbon (AC) with a BET surface area of 1118 m2 g-1 was obtained by chemical activation and thermal treatment of the waste rubberwood sawdust. AC-Graphite, AC-Reduced Graphene Oxide (RGO), and AC-RGO-Chitosan were the types of mCPEs that were utilized. The electrochemical behaviors and effects of pH, concentration, and scan rate were studied using Cyclic voltammetry (CV). Studies on detection were conducted using CV and linear sweep voltammetry. Although all the 3 mCPEs detected Cd2+ and Pb2+ in the simulated wastewater, the CPE with RGO and AC could detect Cd2+ as low as 10.91 µg L-1 and Pb2+ as low as 14.01 µg L-1. The work explored the possibility of using AC as a potential sustainable substitute for graphite in CPE.
... In this last fi eld, several works have focused on the choice of an adsorbent that meets the criteria of effi ciency, stability in the environment, regeneration, and low investment cost especially when it comes to the removal of heavy metals (Zhu et al. 2019;. Our laboratory has tested several adsorbents based on natural materials such as the use of snail shells for the removal of copper from aqueous solutions and the production of valuable compounds (Ouafi , Asri, et al. 2021), the exploitation of powder from pinecones for the removal by adsorption of copper ions from water (Ouafi , Omor, et al. 2021) and the use of sawing for the treatment of heavy metals from contaminated wastewater (Ouafi et al. 2017). ...
... Currently, nonconventional adsorbents like agricultural wastes compete with the usual ones (charcoal, zeolites, and clays) in heavy metals removal, because they are abundant and not expensive. Among these, groundnut shell (Babarinde and Onyiaocha, 2016), acorn waste (Kuppusamy et al., 2017), pine cone (Almendros et al., 2015), fruit peels and sugarcane bagasse (Chao et al., 2014), sawdust (Ouafi et al., 2017), and many other biomass-based materials have been successfully applied for Cr(VI) elimination from wastewater. ...
Carob waste (CW) is an agro-biomass material abundant in nature with potential use for eco-friendly remediation. However, like many biomass-based adsorbents, it suffers from its low adsorption capacity for organic/inorganic pollutants. Therefore, modification using physical and/or chemical means is commonly applied to improve the adsorptive properties of biomass-based adsorbents. In this study, carob waste (CW) and carob waste functionalized with phytic acid (PA-CW), as an ecofriendly product, were applied for the first time for Cr(VI) elimination. Various methods were applied for the material characterization like Fourier-transform infrared spectroscopy, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA and DTG), X-ray photoelectron spectroscopy (XPS), specific surface area and porosity measurements. The results proved that both CW and PA-CW own appropriate features for efficient adsorption. Bach experiments revealed that the optimum parameters for Cr(VI) (100 mg/mL) removal at 25 °C were pH 2, 0.05 g and 0.025 g as adsorbent dose for CW and PA-CW, respectively, over 120 min contact time. The kinetic of adsorption was well-described by the pseudo-second order model, whereas the isotherm modeling fitted well the modified Langmuir model. CW and PA-CW achieved respectively maximum adsorption capacities of 212.4 and 387.9 mg/g, which are among the highest values so far reported for biomass-based adsorbent materials. These results confirmed that CW and PA-CW could be alternative cost-effective adsorbents even for high concentrations of Cr(VI) in industrial wastewaters along with their reduction capacity.
... For that, the treatment of these effluents has been very necessary. Several previous research works have proven some treatment processes for these effluents such as activated carbon adsorption [14], ions exchange [15][16][17][18], chemical precipitation using ferric chloride [19,20], coagulation [21], electrocoagulation [7,22], sequencing batch reactor [23], bio-augmentation [24] … etc. However, all these studies are only focused on chromium removal from these effluents, and they ignored the elimination of sulfides even they also very toxic. ...
The tannery effluents are characterized by high toxic pollutants such as sulfides; used in the tanning of animal’s skin. The mean objective of this work is the evaluation of the pollution degree of various operating units, and the treatment of tannery effluent generated from unhairing-liming unit. According to physicochemical characterization, this effluent was largely basic and very loaded in sulfides, which have harmful effects on human health and the environment as well. Otherwise, the microbiological characterization showed an absence of pathogenic bacteria and a low concentration of mesophilic aerobic flora, because of this effluent toxicity. Thus, the treatment of this effluent is indispensable before its reject into the environment. In fact, chemical precipitation is a promising approach for the treatment of this effluent. In this regard, ferric chloride was used as chemical agent to reduce and removal sulphide ions from this effluent. As result, this treatment gave an excellent abatement rate of sulphide, which reached more than 90% using a pH of 8.5 and a ferric chloride concentration of 1.4 mol/L.
... In the present study, the promotion of plant growth may be due to the metal-absorbing potential of sawdust (Oyeyiola et al., 2017). The absorptive potential of sawdust is due to the availability of hydroxyl, carboxyl, amide, and phenolic functional groups, which may bind metals and reduce their bioavailability (Barakat, 2011;Ouafi et al., 2017;Sahmoune and Yeddou, 2016). These conclusions are confirmed by the δΔ c results presented in Fig. 3. ...
Studies in the literature concern the toxicity of nanoparticles either in a petri dish or in agar media-based tests. Therefore, for environmental relevance, individual and binary mixtures of metal oxide nanoparticles (M-NPs) cadmium oxide (CdO-NP) and copper oxide (CuO-NP) were tested in this study for their effect on Vigna radiata in soil with and without the addition of sawdust. Seed germination was 67% in 100 mg CuO-NP in soil without sawdust. Seeds failed to germinate in 100 mg CdO + 100 mg CuO-NPs in soil without the addition of sawdust and germination was 83% at the same concentration in soil with sawdust. In sawdust added to soil, when compared with control (soil without M-NPs), the maximum reduction in shoot (82%) and root (80%) length and wet (61%) and dry (54%) weight of plant was recorded in CdO-NP treated soil. Similarly, compared with control (soil without sawdust and M-NPs), the percent reduction in shoot (61%) and root (70%) length and wet (44%) and dry (48%) weight was highest in CdO-NP treated soil not supplemented with sawdust. In a binary mixture test (CdO-NP + CuO-NP), the addition of sawdust promoted the above plant growth parameters compared with individual CdO-NP and CuO-NP tests. Cadmium (511 mg/kg for individual and 303 mg/kg for binary mixture tests) and Cu (953 mg/kg for individual and 2954 mg/kg for binary mixture tests) accumulation was higher in plants grown in soil without sawdust. The beneficial effect of sawdust addition was observed in seed germination, plant growth, and metal accumulation. With or without sawdust, the binary mixture of CdO and CuO was antagonistic. These results indicate that sawdust can prevent M-NP-induced toxicity and reduce metal accumulation in plant tissues.
... The initial pH was confirmed as an important parameter in the sorption process in heavy metal removal due to determining the surface charge of sawdust and the degree of ionization of the solution [48,56,57,63,76]. ...
... The adsorption mechanism can be explained as the heavy metal uptake increasing with increasing pH in a certain range and up to a certain value, then decreasing with additional pH increases. According to the mechanism, sorption simultaneously decreases the pH and the H + release and competes with metal cations for sorption sites during the process [54,76]. At low pH, the concentration of positively charged H + ions in solution is high and they bind to the sawdust by electrostatic sorption, thereby competing with copper ions for binding sites. ...
Organic waste materials and semi-products containing cellulose are used as low-cost adsorbents that are able to compete with conventional sorbents. In addition, their capacity to bind heavy metal ions can be intensified by chemical treatments using mineral and organic acids, bases, oxidizing agents, and organic compounds. In this paper, we studied the biosorption capacity of natural and modified wooden sawdust of poplar, cherry, spruce, and hornbeam in order to remove heavy metals from acidic model solutions. The Fourier transform infrared spectroscopy (FTIR) spectra showed changes of the functional groups due to the alkaline modification of sawdust, which manifested in the considerably increased intensity of the hydroxyl peaks. The adsorption isotherm models clearly indicated that the adsorptive behavior of metal ions in treated sawdust satisfied not only the Langmuir model, but also the Freundlich model. The adsorption data obtained for studied sorbents were better fitted by the Langmuir isotherm model for both metals, except for spruce sawdust. Surface complexation and ion exchange are the major mechanisms involved in metal ion removal. We investigated the efficiency of the alkaline modified sawdust for metal removal under various initial concentrations of Cu(II) and Zn(II) from model solutions. The highest adsorption efficiency values (copper 94.3% at pH 6.8 and zinc 98.2% at pH 7.3) were obtained for poplar modified by KOH. For all types of sawdust, we found that the sorption efficiency of modified sorbents was higher in comparison to untreated sawdust. The value of the pH initially increased more in the case of modified sawdust (8.2 for zinc removal with spruce NaOH) and then slowly decreased (7.0 for Zn(II) with spruce NaOH).
... Among these methods, adsorption has increasingly received much attention in recent years due to its unique benefits, especially when wastewater with low metal ion concentration must be treated. Many different kinds of adsorbents have been developed and among them, activated carbon [17][18][19][20][21], activated alumina [22][23][24][25], coated silica gel [26,27] and treated sawdust [28][29][30] are the most used. The objective of the present research is to implement an inexpensive and highly adsorbing mechanism based on coupling two different materials, zeolite and magnetite, into the same particle forming a composite tool that can be used for magnetic removal of harmful ions. ...
Toxic and heavy metals are considered harmful derivatives of industrial activities; they are not biodegradable and their accumulation in living organisms can become lethal. Among other heavy and toxic metals, chromium is considered hazardous, especially in the hexavalent (Cr6+) form. Numerous established studies show that exposure to Cr6+ via drinking water leads to elevated chromium levels in tissues, which may result in various forms of cancer. The purpose of this research is to synthesize magnetite/zeolite-X composite particles for the adsorption and magnetic removal of Cr6+ ions from aqueous solutions. Synthesis and characterization of such composite nanomaterials, along with an initial experimental evaluation of Cr6+ removal from water-based solution, are presented. Results show that zeolite-X is a very promising zeolite form, that when bound to magnetic nanoparticles can be used to trap and magnetically remove toxic ions from aqueous solutions.
Nowadays, a big challenge is developing a sustainable and effective method for removing contaminants like dyes from aqueous solutions. In this regard, Zr-based metal-organic framework (UiO-66-NH2) and sawdust as the ideal adsorbents were used. Due to their low separation in adsorption processes, embedding into alginate and obtaining composite beads are suggested as a suitable strategy. The achieved Ca-alginate/citric acid (CA)-sawdust/UiO-66-NH2 hydrogel beads were used to compare cationic and anionic dyes removal. This sorbent indicated an excellent selectivity for removing methylene blue versus methyl orange in a binary system. pH = 6, adsorbent amount = 80 mg, methylene blue concentration = 10 mg/L, and contact time = 420 min were achieved as optimal parameters on methylene blue adsorption with an adsorption capacity of about 26 mg/g. The removal process of methylene blue followed linear Freundlich isotherm and nonlinear pseudo-2nd-order kinetic models. The regeneration test demonstrated methylene blue removal efficiency higher than about 89 % after 9 cycles. According to the outcomes, methylene blue could be attached to the adsorbent surface through the electrostatic, hydrogen bonding, and π-π interactions of the aromatic rings. These results confirm the potential of Ca-alginate/CA-sawdust/UiO-66-NH2 hydrogel beads as a selective bio-sorbent for cationic dye removal.
