Metal Sorption Research Articles

Biochar heavy metal removal in aqueous solution depends on feedstock type and pyrolysis purging gas

The effectiveness of biochar as a sorptive material to remove contaminants, particularly heavy metals, from water is dependent on biomass type and pyrolysis condition. Biochars were produced from pulp mill sludge (PMS) and rice straw (RS) with nitrogen (N2) or carbon dioxide (CO2) as the purging gas. The sorptive capacity of the biochars for cadmium(II), copper(II), nickel(II) and lead(II) was studied. The heavy metal adsorption capacity was mainly affected by biomass type, with biochars adsorption capacities higher for lead(II) (109.9–256.4 mg g−1) than for nickel(II) (40.2–64.1 mg g−1), cadmium(II) (29.5–42.7 mg g−1) and copper(II) (18.5–39.4 mg g−1) based on the Langmuir adsorption model. The highest lead(II) adsorption capacities for PMS and RS biochars were 256.4 and 133.3 mg g−1, respectively, when generated using N2 as the purging gas. The corresponding lead(II) adsorption capacities were 250.0 and 109.9 mg g−1, respectively, when generated using CO2 as the purging gas. According to the intraparticle diffusion model, 30–62% of heavy metal adsorption was achieved in 1 h; film diffusion was the rate-dominating step, whereas pore diffusion was a rate-limiting step. Ion exchange and complexation between heavy metals and biochar surface functional groups such as carbonyl and hydroxyl groups were effective mechanisms for heavy metal sorption from the aqueous solution. We conclude that proper selection of both the feedstock type and the purging gas is important in designing biochars for the effective removal of potentially toxic metals from wastewater.

Zinc-Containing Effluent Treatment Using Shewanella xiamenensis Biofilm Formed on Zeolite.

The sorption properties of Shewanella xiamenensis biofilm formed on zeolite (mineral-organic sorbent) as a sorbent have been investigated aiming to determine its suitability for complex zinc-containing effluent treatment. The optimum conditions for metal sorption from synthetic solutions were evaluated by changing the pH, zinc concentration, temperature, and time of sorption. The highest removal of metal ions was attained at pH range 3.0–6.0 within 60–150 min of sorbent-sorbate contact. The results obtained from the equilibrium studies were described using the Langmuir, Freundlich, and Temkin models. Maximum sorption capacity of the sorbent calculated from the Langmuir model changed from 3.4 to 6.5 mg/g. High coefficient of determination values calculated for pseudo-second-order and Elovich models indicate the predominant role of chemisorption in metal removal. Gibbs energy and ∆H° values point at the spontaneous and endothermic character of the sorption. The effect of pH and biosorbent mass on Zn(II) sorption from industrial effluent with an initial Zn(II) concentration of 52.8 mg/L was tested. Maximum removal of zinc ions (85%) was achieved at pH 6.0 by applying a two-step treatment system.

Sorption Recovery of Platinum Metals from Production Solutions of Sulfate-Chloride Leaching of Chromite Wastes

This paper discusses the scientific rationale for methods of platinum metals sorption centralization from saturated solutions with a high content of macrocomponents. Methods of sorption centralization of platinum and iridium using local anionites such as AH-31, AB-17-8, Purolite S985 are described. The sorbents used were conditioned to remove organic and mineral impurities. The sorption isotherms of platinum group metals 1/EC=f(1/Cp) at a temperature of 20 °C and a duration of 24 h were plotted. The data on the sorption recovery of platinum and iridium from individual and combined sulfate-chloride solutions were determined. Isotherms of iridium sorption from sulfate-chloride solution are formed. Results of the apparent sorption equilibrium constant and values of standard Gibbs energy (ΔG, kJ/mol) of ion exchange for sorption of platinum and iridium from individual and combined sulfate-chloride solutions are presented. Linearized isotherms and kinetic curves of joint sorption of platinum and iridium from sulfate-chloride solution are described. Comparative sorption of the platinum-group metals (PGM) by anionites AB-17-8 and Purolite S985 from sulfate-chloride solutions is shown. The sorption diagram of platinum and iridium from sulfate-chloride product solutions is presented. It has been revealed that complete recovery is achieved using chelation ion-exchange resin Purolite S985, with recovery of Pt up to 95% and Ir more than 73%. The sorption process is accompanied by intradiffusion constraints that are confirmed by the analysis of kinetic curves using Schmukler and Boyd–Adams models.

Sorption of Heavy Metal Ions by Composite Materials Based on Polycarboxylic Acids and Bentonite Clay

The paper shows the study results of sorption capacities of composite gels based on polyacrylic and polymethacrylic acids with bentonite clay as the mineral filler concerning heavy metal ions (Pb+2, Cu+2, Ni+2, Zn+2, Fe+2, Cd+2). The binding of metal ions to gels occurs through the formation of electrostatic bonds between the charged surface of bentonite clay and ionogenic functional groups of polymers in the composition, as well as the coordination bonds between metal ions and unshared pairs of oxygen electrons in the functional groups of polymers. The gel swelling degree decreases in metal solutions with increasing metals concentration and the content of BC in the composite. The sorption and desorption of heavy metal ions from the polymer-clay composites from model solutions and samples of industrial wastewater from the Kazakhstani metallurgical plants were evaluated. The adjustment of the pH, the temperature of the medium and the clay content in the composite leads to increasing the degree of sorption and achieving regeneration of the used composite gels in certain media. The data obtained testify to the prospects of using these composites as effective sorbents of heavy metals from industrial wastewaters expanding the range of composite materials for wastewater treatment.

Microbial Community Composition Correlates with Metal Sorption in an Ombrotrophic Boreal Bog: Implications for Radionuclide Retention

Microbial communities throughout the 6.5 m depth profile of a boreal ombrotrophic bog were characterized using amplicon sequencing of archaeal, fungal, and bacterial marker genes. Microbial populations and their relationship to oxic and anoxic batch sorption of radionuclides (using radioactive tracers of I, Se, Cs, Ni, and Ag) and the prevailing metal concentrations in the natural bog was investigated. The majority of the detected archaea belonged to the Crenarchaeota, Halobacterota, and Thermoplasmatota, whereas the fungal communities consisted of Ascomycota, Basidiomycota, and unclassified fungi. The bacterial communities consisted mostly of Acidobacteriota, Proteobacteria, and Chloroflexi. The occurrence of several microbial genera were found to statistically significantly correlate with metal concentrations as well as with Se, Cs, I, and Ag batch sorption data. We suggest that the metal concentrations of peat, gyttja, and clay layers affect the composition of the microbial populations in these nutrient-low conditions and that particularly parts of the bacterial and archaeal communities tolerate high concentrations of potentially toxic metals and may concurrently contribute to the total retention of metals and radionuclides in this ombrotrophic environment. In addition, the varying metal concentrations together with chemical, mineralogical, and physical factors may contribute to the shape of the total archaeal and bacterial populations and most probably shifts the populations for more metal resistant genera.

Predicting the sorption efficiency of heavy metal based on the biochar characteristics, metal sources, and environmental conditions using various novel hybrid machine learning models

Heavy metals in water and wastewater are taken into account as one of the most hazardous environmental issues that significantly impact human health. The use of biochar systems with different materials helped significantly remove heavy metals in the water, especially wastewater treatment systems. Nevertheless, heavy metal’s sorption efficiency on the biochar systems is highly dependent on the biochar characteristics, metal sources, and environmental conditions. Therefore, this study implicates the feasibility of biochar systems in the heavy metal sorption in water/wastewater and the use of artificial intelligence (AI) models in investigating efficiency sorption of heavy metal on biochar. Accordingly, this work investigated and proposed 20 artificial intelligent models for forecasting the sorption efficiency of heavy metal onto biochar based on five machine learning algorithms and bagging technique (BA). Accordingly, support vector machine (SVM), random forest (RF), artificial neural network (ANN), M5Tree, and Gaussian process (GP) algorithms were used as the key algorithms for the aim of this study. Subsequently, the individual models were bagged with each other to generate new ensemble models. Finally, 20 intelligent models were developed and evaluated, including SVM, RF, M5Tree, GP, ANN, BA-SVM, BA-RF, BA-M5Tree, BA-GP, BA-ANN, SVM-RF, SVM-M5Tree, SVM-GP, SVM-ANN, RF-M5Tree, RF-GP, RF-ANN, M5Tree-GP, M5Tree-ANN, GP-ANN. Of those, the hybrid models (i.e., BA-SVM, BA-RF, BA-M5Tree, BA-GP, BA-ANN, SVM-RF, SVM-M5Tree, SVM-GP, SVM-ANN, RF-M5Tree, RF-GP, RF-ANN, M5Tree-GP, M5Tree-ANN, GP-ANN) are introduced as the novelty of this study for estimating the heavy metal’s sorption efficiency on the biochar systems. Also, the biochar characteristics, metal sources, and environmental conditions were comprehensively assessed and used, and they are considered as a novelty of the study as well. For this aim, a dataset of sorption efficiency of heavy metal was collected and processed with 353 experimental tests. Various performance indexes were applied to evaluate the models, such as RMSE, R2, MAE, color intensity, Taylor diagram, box and whiskers plots. This study’s findings revealed that AI models could predict heavy metal’s sorption efficiency onto biochar with high reliability, and the efficiency of the ensemble models is higher than those of individual models. The results also reported that the SVM-ANN ensemble model is the most superior model among 20 developed models. The predictive model proposed that heavy metal’s efficiency sorption on biochar can be accurately forecasted and early warning for the water pollution by heavy metal.

Isolation of Chitin from Black Soldier Fly (Hermetia illucens) and Its Usage to Metal Sorption.

Chitin has become a desirable raw material used in various areas of life. The black soldier fly (Hermetia illucens) can be a source of this substance. In the literature, there are many methods of obtaining chitin but there is no one universal method of isolating it. In this publication, we present various procedures for the isolation of chitin from H. illucens pupal exuviae. The obtained chitin variants were characterized using different techniques (optical and confocal microscopy, FTIR, XRD, EDX, thermogravimetric analysis). The tested chitin isolated with an efficiency of 5.69–7.95% was the α form with a crystallinity degree of 60% and maximum degradation temperature of 392 °C. Furthermore, we characterized the nickel ion biosorption process on chitin and proposed the mechanism of this process to be ion exchange and complexation. There have been no such studies thus far on the isolation of chitin from H. illucens exuviae or on the biosorption of nickel ions on this type of biosorbent. The conducted research can be used to develop the application of chitin as a metal biosorbent that can be obtained with relatively high efficiency and good sorption properties.

Adsorptive removal of lead and cadmium ions from aqueous solutions by aluminium oxide modified onion skin wastes: Adsorbent characterization, equilibrium modelling and kinetic studies

Aluminium oxide modified onion skin waste (Al2O3/OSW) was characterized and used for adsorption of metal ions (Pb2+ and Cd2+) in this study, and the relations between sorbent properties and metal ion sorption were investigated. The effects of adsorption process conditions on metal ion removal efficiency, including initial cation concentration, contact time, adsorbent dosage and pH, were examined. The obtained adsorption data were analyzed by various adsorption isotherm and kinetic models. It was found that the optimum values of the initial concentration, contact time, adsorbent dosage and pH were 10 mg/L, 120 min, 1.6 g/L and 6.0, respectively. At these optimum conditions, maximum removal percentages of Pb2+ and Cd2+ were 91.23 and 94.10%, respectively. The isotherm and kinetic studies showed a multilayer adsorbate-adsorbent system with the dominance of the chemisorption mechanism. The study concluded that onion skin waste is a viable, cheap and effective alternative for removing heavy metal ions from water/wastewater.

Magnetic water treatment in a wastewater treatment plant: Part II - Processing waters and kinetic study

Magnetic sorption process is applied to real wastewater effluents from a Wastewater Treatment Plant. The complex media sorption is done by using different types of magnetic particles (resin and polymeric covered magnetite) giving good results for removing detergents, phosphates and COD and moderate results for the sorption of nitrogen and several heavy metals. Important kinetic parameters were obtained by data fitting for the pseudo first and second order, and for simplified Elovich models. Regeneration and reuse of the magnetic particles using a chemical-free method was also tested, as well as the effect of the concentration of the particles in the removal efficiency (which proved to be relevant).

New derivatives of urea-grafted alginate for improving the sorption of mercury ions in aqueous solutions

Chemically-modified alginate (obtained by grafting urea on alginate, with different ratios; alginate-urea (1:1) and its new derivatives alginate-urea (1:2) with an exceed of the percent of amino group by 7%) was successfully tested for mercury sorption in aqueous solutions. The influence of pH on metal sorption was first investigated: optimum pH was close to 5.5. Sorption isotherms were modeled using the Langmuir and the Sips equations, and sorption capacity slightly increased with the increased of the % of–NH2 in the sorbent and the maximum sorption capacity exceeded 200 mg Hg l−1 (1.07 mmol Hg g−1; for alginate-urea (1:2)), this means two times the sorption capacity of reference material (i.e., non-modified alginate), and also has a capacity improved compared to alginate-urea (1:1). Under selected experimental conditions the equilibrium was reached with 6–8 h of contact and the kinetic profiles were modeled using the pseudo-first order equation (PFORE), the pseudo-second-order rate equation (PSORE) and the resistance to intraparticle diffusion (RIDE). Surface functional groups, notably; –NH2, –OH and –COOH, were involved in mercury sorption by alginate-urea, suggesting the ion exchange, complexation and/or electrostatic interaction of Hg(II) on the alginate-urea surface. The use of this material, environmentally friendly and simply obtained from a renewable resource, reveals promising for the treatment of low-metal concentration effluents: sorption capacities are comparable to alternative academic and commercials sorbents.

Efficiency of sorption of metals from electronic waste by microscopic algae

The extraction of metals from e-waste is currently not well understood. In this regard, a promising method for the extraction of metals was chosen, namely the biotechnological method. E-waste includes various categories of waste. This complicates the search and development of a universal method for disposing of electronic waste. In this regard, one category of e-waste was selected, namely mobile phone screens. The article presents the results of experimental studies on assessing the efficiency of metal sorption from mobile phone screens by microscopic algae at various parameters of biosorption.

Comparative study for bioremediation of cobalt contaminated aqueous solutions by two types of marine macroalgae

Biosorption is an efficient method for removing heavy metals from wastewater. Two dried marine macroalgae species; Ulva fasciata and Colpomenia sinuosa were used for bioremediation of cobalt polluted aqueous solutions. It was established that the optimum biosorption takes place at pH 6.0 and 7.0 for U. fasciata and C. sinuosa, respectively, with contact time 60 min for both species, initial Co(II) concentration 50 and 80 mg/L for U. fasciata and C. sinuosa, respectively, and biomass dosage 0.05 g/50 mL for both species. The biosorption mechanism of Co(II) onto the algal biomass was investigated utilizing the standard techniques. The isotherm models elucidated that Langmuir model fits the experimental data of Co(II) adsorption more than Freundlich model. The maximum biosorption capacity (qmax) obtained for C. sinuosa (62.5 mg/g) was greater than that for U. fasciata (40.0 mg/g). It was also found that the biosorption process using U. fasciata and C. sinuosa followed the second-order kinetic. The effect of calcium, magnesium, and sodium ions (Ca+2, Mg+2, and Na+) on the metal sorption potential by biosorbents was studied. The adsorption behaviour of U. fasciata and C. sinuosa in treating wastewater sample collected from Edku Lake was also investigated.

Searching for optimum adsorption curve for metal sorption on soils: comparison of various isotherm models fitted by different error functions

Studies comparing numerous sorption curve models and different error functions are lacking completely for soil-metal adsorption systems. We aimed to fill this gap by studying several isotherm models and error functions on soil-metal systems with different sorption curve types. The combination of fifteen sorption curve models and seven error functions were studied for Cd, Cu, Pb, and Zn in competitive systems in four soils with different geochemical properties. Statistical calculations were carried out to compare the results of the minimizing procedures and the fit of the sorption curve models. Although different sorption models and error functions may provide some variation in fitting the models to the experimental data, these differences are mostly not significant statistically. Several sorption models showed very good performances (Brouers-Sotolongo, Sips, Hill, Langmuir-Freundlich) for varying sorption curve types in the studied soil-metal systems, and further models can be suggested for certain sorption curve types. The ERRSQ error function exhibited the lowest error distribution between the experimental data and predicted sorption curves for almost each studied cases. Consequently, their combined use could be suggested for the study of metal sorption in the studied soils. Besides testing more than one sorption isotherm model and error function combination, evaluating the shape of the sorption curve and excluding non-adsorption processes could be advised for reliable data evaluation in soil-metal sorption system.

Synthesis of Magnesium Modified Biochar for Removing Copper, Lead and Cadmium in Single and Binary Systems from Aqueous Solutions: Adsorption Mechanism

Biochar modification can enhance the properties associated with porosity and functional groups and has been identified as an effective way to improve adsorption capacity. Modified corncob biochars pretreated by different contents of MgCl2 are obtained through slow pyrolysis; then, this work explores the adsorption abilities towards heavy metals. After modification, biochars mainly impregnate carbon surface with Mg(OH)2 and MgO particles. The best mass ratio of magnesium (Mg)/feedback is 15% for modified biochar, and 15%Mg-BC has much higher (2.36–9.34 times) metal sorption capacity than pristine biochar. Batch adsorption experiments show that copper (Cu(II)) and lead (Pb(II)) on adsorbents follow a pseudo-second-order model and cadmium (Cd(II)) follows an intraparticle diffusion model. The adsorption isotherm of Cu(II) fits well with the Langmuir model, and Pb(II) and Cd(II) fit with the Freundlich model. In the binary system, modified biochar still effectively removes metals, but the sorption capacity of metals decreases rapidly because of competitive sorption. The main adsorption mechanisms of metals include surface precipitation, cation π-banding, complexation, and ion exchange. The results show that Mg-modified biochar may be an environmentally friendly material for reducing the water pollution of heavy metals.

Effect of pedogenic iron-oxyhydroxide removal on the metal sorption by soil clay minerals

PurposeThe close association of Fe-oxyhydroxides and clay minerals might influence the sorption properties of these components. We aimed to study the effect of removing the pedogenic Fe-oxyhydroxides on the sorption of Cd, Cu, Pb, and Zn by the clay mineral particles in soils with contrasting pH.MethodsCompetitive batch sorption experiments before and after Fe-oxyhydroxide extraction in soils were carried out together with the direct analysis of the metal sorption on individual particles of ferrihydrite, smectite, and illite/smectite by TEM.ResultsFerrihydrite was a more effective metal sorbent than clay minerals, although its removal resulted in decreased sorption only for Cd, Cu, and Zn. Ferrhydrite coating blocked metals’ access for certain sorption sites on clay surfaces, which were only accessible for Pb as the most efficient competitor after removing the coating. This observation was the most remarkable for the smectite particles in the alkaline soil. Mineral surfaces sorbed higher Cu than Pb concentrations and higher Zn than Cd concentrations despite the former metals’ lower bulk sorption. Thus, organic surfaces and precipitation contributed to Pb and Cd’s retention to a greater extent than for Cu and Zn. The structural Fe of smectite also promoted the metal sorption in both soils.ConclusionRemoval of iron-oxyhydroxide coatings from the soil affects metal sorption selectively. Direct study of metal sorption on individual soil particles enables us to gain a more in-depth insight into soil minerals’ role in this process.

Investigation on the removal of bivalent cadmium ions from aqueous solution and treatment of industrial wastewater using new alumina interfaced biocarbon

The presence of heavy metals in water and wastewater is becoming a severe environmental and public health concern. It may contribute variety of adverse environmental and human health effects due to their acute and chronic exposure through air, water and food chain. They are released into the aquatic environment from many industrial activities. The present research paper deals with the adsorption capacity of the biocarbon material produced from the leaves of Lawsonia inermis plant. The biocarbon was prepared by the H2SO4 activation process. The adsorption capacity of the biocarbon was evaluated by considering the effect of various parameters such as pH of the solution, biocarbon dose, contact time, and initial metal ions concentration and to optimize the conditions for maximum adsorption. The metal ion uptake capacity of the biocarbon was tested in the stimulated wastewater containing bivalent cadmium ions. The maximum uptake of 97.85% of the Cd (II) metal ions was observed at the equilibrium time of 3.0 hours at a dose of 3.0 g and at the pH of 4.5 in the stimulated wastewater. In the real sample analysis, electroplating industry wastewater is used for the removal of cadmium (II) ions. The results indicate that 95.16% of ions were effectively removed at the same experimental conditions. It is also further noted that the metal sorption capability of the adsorbent is higher with rising concentration of metal ions in the solution. The percentage of adsorption of the metal ions was also significantly increased with rise of temperature of the wastewater.

Comparison of Structure and Adsorption Properties of Mesoporous Silica Functionalized with Aminopropyl Groups by the Co-Condensation and the Post Grafting Methods.

The adsorptive potential has been evaluated for the aminopropyl functionalized mesoporous silica materials obtained by co-condensation and post grafting methods. Nitrogen sorption, small angle neutron and X-ray scattering (SANS and SAXS) demonstrated high surface area and well-ordered hexagonal pore structure suitable for applications as adsorbents of metals from waste waters. A comparison of Cr(VI) adsorption properties of the materials prepared by different functionalization methods has been performed. The obtained results demonstrated the adsorption capacity due to the affinity of the chromium ions to the amino groups, and showed that co-condensation of tetraethoxysilane (TEOS) and 3-aminopropyl triethoxysilane (APTES) resulted in higher metal sorption capacity of the materials compared to post-synthesis grafting of aminopropyl groups onto the mesoporous silica particles.

Use of fibroin polypeptide from silk processing waste as an effective biosorbent for heavy metal removal

AbstractSilk fibroin was extracted from Bombyx mori cocoon and used as a biosorbent to remove Pb2+, CrO42−, Cu2+, and Co2+ from aqueous solutions. The sorption isotherms for the metals in fibroin were determined, and a thermodynamic analysis (ΔG°, ΔH°, and ΔS°) of the sorption process showed that the metal sorption in fibroin was physical, spontaneous, and endothermic. The sorption kinetics data was found to match well with the modified pseudo‐second‐order rate model, and the sorption rate constant was determined based on a rectified approach of model fitting. It was shown that the sorption rate constant was largely independent of the initial sorbate concentration, which was expected because it is a specific quantity characterizing the relationship between sorbate concentration and the rate of sorption. The metal‐loaded fibroin could be regenerated easily by stripping the metal off fibroin using ethylenediamine tetraacetic acid, and the sorption performance of the regenerated fibroin remained the same as pristine fibroin. When used repeatedly over 10 sorption‐regeneration cycles, the fibroin biosorbent showed no change in sorption capacity, which demonstrates the excellent stability and reusability of the fibroin biopolymer for metal capture from water.

Efficient metals removal from waste pickling liquor using novel task specific ionic liquids - classical manner and encapsulation in polymer shell

In the presented studies, extractant N′-(2-ethylhexyloxy)pyridine-4-carboximidamide (EH4IA), and its quaternary salts (4-[1-amine(2-ethylhexyloxyimine)]-1-propylpyridinium chloride (EH4IA-Cl) and 4-[1-amine(2-ethylhexyloxyimine)]-1-propylpyridinium bromide (EH4IA-Br)) were tested as the selective extractants of Zn(II) from waste pickling liquor, as well as after encapsulation, as sorbents enabling separation of Fe(II) and (III), Zn(II), and Pb(II). In the extraction study various factors affecting zinc(II) extraction, and its separation from Fe(II), such as NaCl, HCl, and the metals ions concentration in the aqueous feed solution, as well as structure and concentration of the extractant were analyzed. The metals sorption with the encapsulated extractants was found to be affected by the structure of the encapsulated ionic liquid, pH of the aqueous phase, shaking time, concentration of the metals ions, NaCl, HCl, and temperature of the process. The obtained results enabled to propose the scheme of waste pickling liquor treatment, and laboratory tests confirmed very high potential of the method and the selected to extraction and sorption stages extractant - EH4IA-Br.

Cross-Linked and Functionalized Acrylic Polymers: Efficient and Reusable Sorbents for Zn(II) Ions in Solution

The efficiency of the three types of cross-linked and functionalized with triethylenetetramine (As30 and As32) and acylate diethylenediamine (Cm26) acrylic polymers towards zinc ions from synthetic wastewaters has been investigated under different experimental conditions. The sorption and reusability of metal ions on three types of polymer were studied by the static and dynamic method. The effects of contact time, the initial metal ion concentration, pH, sorbent mass and temperature on the adsorption capacity of the three types of cross-linked and functionalized acrylic polymers were investigated. The thermodynamic parameters associated with the adsorption process were evaluated, and obtained values suggested an exothermic process. The experimental data confirm much better to the Langmuir isotherm than the Freundlich, Temkin, Dubinin–Radushkevich, Sips and Flory–Huggins isotherms. The obtained values for the separation factor, RL were less than 1 one which shows that the adsorption process was favorable. The obtained results indicated that the Cm26 has a higher sorption capacity (1135.77 43 mg g−1) towards zinc ions than As32 (1059.47 43 mg g−1) and As 30 (857.77 43 mg g−1) at 293 K. The adsorption capacity sorbents towards Zn2+ ions after five consecutive sorption/desorption cycles, with 0.1 M Na2CO3 aqueous solution as eluent, decreased with about 5% of the initial sorption capacity and this fact recommended the potential of these functionalized polymers in the removal of Zn(II) ions from residual waters.