Adsorption of Pb2+ and Cd2+ onto a Novel Activated Carbon‐Chitosan Complex

A novel activated carbon‐chitosan complex adsorbent (ACCA) was prepared via the crosslinking of glutaraldehyde and activated carbon‐(NH₂‐protected) chitosan complex under microwave irradiation. The surface morphology of this adsorbent was characterized. The adsorption of ACCA for Pb²⁺ and Cd²⁺ was investigated. The results demonstrate that ACCA has higher adsorption capacity than chitosan. The adsorption follows pseudo first‐order kinetics. The isotherm adsorption equilibria are better described by Freundlich and Dubinin‐Radushkevich isotherms than by the Langmuir isotherm. The adsorbent can be recycled. These results have important implications for the design of low‐cost and effective adsorbents in the removal of heavy metal ions from wastewaters.     

Adsorption characteristics of metal ions by CO2-fixing Chlorella sp. HA-1

Single and binary metal systems were employed to investigate the removal characteristics of Pb²⁺, Cu²⁺, Cd²⁺, and Zn²⁺ by Chlorella sp. HA-1 that were isolated from a CO₂ fixation process. Adsorption test of single metal systems showed that the maximum metal uptakes were 0.767 mmol Pb²⁺, 0.450 mmol Cd²⁺, 0.334 mmol Cu²⁺ and 0.389 mmol Zn²⁺ per gram of dry cell. In the binary metal systems, the metal ions on Chlorella sp. HA-1 were adsorbed selectively according to their adsorption characteristics. Pb²⁺ ions significantly inhibited the adsorption of Cu²⁺, Zn²⁺, and Cd²⁺ ions, while Cu²⁺ ions decreased remarkably the metal uptake of Cd²⁺ and Zn²⁺ ions. The relative adsorption between Cd²⁺ and Zn²⁺ ions was reduced similarly by the presence of the other metal ions.     

Removal of Cu2+ and Pb2+ ions from aqueous solutions by starch-graft-acrylic acid/montmorillonite superabsorbent nanocomposite hydrogels

In this study, the removal of copper(II) and lead(II) ions from aqueous solutions by Starch-graft-acrylic acid/montmorillonite (S-g-AA/MMT) nanocomposite hydrogels was investigated. For this purpose, various factors affecting the removal of heavy metal ions, such as treatment time with the solution, initial pH of the solution, initial metal ion concentration, and MMT content were investigated. The metal ion removal capacities of copolymers increased with increasing pH, and pH 4 was found to be the optimal pH value for maximum metal removal capacity. Adsorption data of the nanocomposite hydrogels were modeled by the pseudo-second-order kinetic equation in order to investigate heavy metal ions adsorption mechanism. The observed affinity order in competitive removal of heavy metals was found Cu²⁺ > Pb²⁺. The Freundlich equations were used to fit the equilibrium isotherms. The Freundlich adsorption law was applicable to be adsorption of metal ions onto nanocomposite hydrogel.     

Competitive Adsorption of Ag+, Pb2+, Ni2+, and Cd2+ Ions on Vermiculite

Competitive adsorption of Ag⁺, Pb²⁺, Ni²⁺, and Cd² ions on vermiuculite in a binary, ternary, and quaternary mixture was investigated in batch experiments. The effects of the presence of Ag⁺, Ni²⁺, and Cd²⁺ ions on the adsorption of Pb²⁺ ions were investigated in terms of the equilibrium isotherm. Experimental results indicated that Pb²⁺ ions always favorably adsorbed on vermiculite over Ag⁺, Ni²⁺, and Cd²⁺ ions. The adsorption equilibrium data of Pb²⁺ ions better fitted the Langmuir model than the Freundlich model. The results showed that the pseudo-second-order kinetics model was in good agreement with the experimental results for all metal ions, and the adsorption rate among the metal ions followed Ag⁺ > Pb²⁺ > Ni²⁺ > Cd²⁺. The desorption and regenration study indicated that vermiculite can be used repeatedly and be suitable for the design of a continuous process.     

Removal of Cd2+, Cu2+, Ni2+, and Pb2+ ions from aqueous solutions using tururi fibers as an adsorbent

This work investigates the removal of Cd²⁺, Cu²⁺, Ni²⁺, and Pb²⁺ ions from aqueous solutions using tururi fibers as an adsorbent under both batchwise and fixed‐bed conditions. It was found that modification of the tururi fibers with sodium hydroxide increased the adsorption efficiencies of all metal ions studied. The fractional factorial design showed that pH, adsorbent mass, agitation rate, and initial metal concentration influenced each metal adsorption differently. The kinetics showed that multi‐element adsorption equilibria were reached after 15 min following pseudo‐second‐order kinetics. The Langmuir, Freundlich, and Redlich–Peterson models were used to evaluate the adsorption capacities by tururi fibers. The Langmuir model was found to be suitable for all metal ions. Breakthrough curves revealed that saturation of the bed was reached in 160.0 mL with Cd²⁺ and Cu²⁺, and 52.0 mL with Ni²⁺ and Pb²⁺. The Thomas model was applied to the experimental data of breakthrough curves and represented the data well. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40883.     

Removal of Pb2+ and Cd2+ from drinking water using polysaccharide extract isolated from cactus pads (Opuntia ficus indica)

The use of a polysaccharide extract isolated from cactus pads (Opuntia ficus indica) as a low‐cost adsorbent for the removal of Pb²⁺ and Cd²⁺ from water was investigated. The Brunauer?Emmett?Teller study showed that the surface area of the extract powder was approximately 2.373 m²/g. Inductively coupled plasma optical emission spectrometry was used to monitor changes in ion concentrations during the adsorption. The adsorption mechanism was studied as a function of physicochemical variables such as initial metal ion concentration, adsorbent dosage, contact time, and pH of the solution. The results indicated that the adsorption percentage of the two cations increased with contact time, attaining equilibrium at 150 and 120 min for Cd²⁺ and Pb²⁺, respectively. At these optimal times, the adsorption capacity of Pb²⁺ and Cd²⁺ increased with increasing pH. Langmuir, Freundlich, Toth, Dubinin–Radushkevich, Sips, and Redlich–Peterson isotherm models were thereafter applied to understand the adsorption mechanism. The qe plot against C_e for the Toth isotherm model had the best fit with low error values and the highest correlation coefficient (R²) values of 0.9973 and 0.9953 for Pb²⁺ and Cd²⁺, respectively. Therefore, the isotherm study reveals that the adsorption mechanism involved is complex because of the presence of different interactions (such as ionic exchange and coagulation), yielding maximum adsorption capacities of 256 and 151 gm/L for Pb²⁺ and Cd²⁺, respectively. Generally, the polysaccharide extract exhibited higher adsorption capacity of Pb²⁺ than of Cd²⁺ under similar conditions. Besides the removal capacities reported in this study, the adsorbent regeneration and its reusability was also investigated. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43913.     

Functionalized nanostructured silica by tetradentate-amine chelating ligand as efficient heavy metals adsorbent : Applications to industrial effluent treatment

Organofunctionalized nanostructured silica SBA-15 with tri(2-aminoethyl)amine tetradentate-amine ligand was synthesized and applied as adsorbent for the removal of Cu²⁺, Pb²⁺, and Cd²⁺ from both synthetic wastewater and real paper mill and electroplating industrial effluents. The prepared materials were characterized by XRD, N₂ adsorption-desorption, TGA, and FT-IR analysis. The Tren-SBA-15 was found to be a fast adsorbent for heavy metal ions from single solution with affinity for Cu²⁺, Pb²⁺, than for Cd²⁺ due to the complicated impacts of metal ion electronegativity. The kinetic rate constant decreased with increasing metal ion concentration due to increasing of ion repulsion force. The equilibrium batch experimental data is well described by the Langmuir isotherm. The maximum adsorption capacity was 1.85 mmol g^?1 for Cu²⁺, 1.34 mmol g^?1 for Pb²⁺, and 1.08 mmol g^?1 for Cd²⁺ at the optimized adsorption conditions (pH=4, T=323 K, t=2 h, C₀=3 mmol L^?1, and adsorbent dose=1 g L^?1). All Gibbs energy was negative as expected for spontaneous interactions, and the positive entropic values from 103.7 to 138.7 J mol^?1 K^?1 also reinforced this favorable adsorption process in heterogeneous system. Experiment with real wastewaters showed that approximately a half fraction of the total amount of studied metal ions was removed within the first cycle of adsorption. Hence, desorption experiments were performed by 0.3M HCl eluent, and Tren-SBA-15 successfully reused for four adsorption/desorption cycles to complete removal of metal ions from real effluents. The regenerated Tren-SBA-15 displayed almost similar adsorption capacity of Cu²⁺, Pb²⁺, and Cd²⁺ even after four recycles. The results suggest that Tren-SBA-15 is a good candidate as an adsorbent in the removal of Cu²⁺, Pb²⁺, and Cd²⁺ from aqueous solutions.     

L-cystein modified bentonite-cellulose nanocomposite (cellu/cys-bent) for adsorption of Cu2+, Pb2+, and Cd2+ ions from aqueous solution

In this study, L-cystein modified bentonite-cellulose (cellu/cys-bent) nanocomposite was synthesized and characterized by XRD, FTIR, SEM with EDS, TGA, and TEM techniques. In order to optimize the process the effect of various operational parameters such as pH, adsorbent dosage, contact time, and temperature were also investigated. The adsorption experiments were carried out in initial concentrations range of 20-100 mg L^?1and the adsorbent affinity for metal ions was found to be in order of Cu²⁺ > Pb²⁺ > Cd²⁺. The optimum pH for adsorption of Cu²⁺ and Cd²⁺ was observed at 5 while for Pb²⁺ it was pH 6. Based on the Langmuir model, the maximum adsorption capacity of Cu²⁺, Pb²⁺, and Cd²⁺ at 50^?C was found to be 32.36, 18.52, and 16.12 mg g^?1, respectively. The Langmuir isotherm and pseudo-second order model were found to be better fitted than the other isotherms and kinetic models. The results of thermodynamic parameters confirmed the process to be endothermic and spontaneous in nature.     

Comparative Study of Zn2+, Cd2+, and Pb2+ Removal From Water Solution Using Natural Clinoptilolitic Zeolite and Commercial Granulated Activated Carbon. Equilibrium of Adsorption

Abstract

The aim of this work is to study the effectiveness of regional, low-cost natural clinoptilolitic zeolite tuff in heavy metal ions removal from aqueous solution, through comparative study with commercial granulated activated carbon. The equilibrium of adsorption of Cd²⁺, Pb²⁺, and Zn²⁺ on both adsorbents have been determined at 25, 35, and 45°C in batch mode. The granulated activated carbon has shown around three times higher adsorption capacity for Cd²⁺ and Zn²⁺ than natural zeolite, and almost the same adsorption capacity for Pb²⁺ as the natural zeolite. The metal ion selectivity series Pb²⁺ > Cd²⁺ > Zn²⁺, on a mass basis, has been obtained on both adsorbents. The Langmuir and Freundlich model have been used to describe the adsorption equilibrium. The thermodynamic parameters were calculated from the adsorption isotherm data obtained at different temperatures. The study of the influence of the acidity of the metal ion aqueous solution has shown an increase of metal ion uptake with increase of the pH. The sorption mechanism of Cd²⁺, Pb²⁺, and Zn²⁺ on natural zeolite changes from ion-exchange to ion-exchange and adsorption of metal-hydroxide with increase of the pH from 2 to 6 (and 7 for Zn²⁺). The preliminary cost calculation, based on adsorbents maximum adsorption capacity and their price, have revealed the potential of natural zeolite as an economic alternative to the granulated activated carbon in the treatment of heavy metal polluted wastewater.     

Synthesis,characterization, metal sorption,and biological activity of poly(N‐heterocylic acrylamide)

N‐heterocyclic acrylamide monomers were prepared and then transferred to the corresponding polymers to be used as an efficient chelating agent. Polymers reacted with metal nitrate salts (Cu²⁺, Pb²⁺_, Mg²⁺, Cd²⁺, Ni²⁺, Co²⁺_, Fe²⁺) at 150°C to give metal‐polymer complexes. The selectivity of the metal ions using prepared polymers from an aqueous mixture containing different metal ion sreflected that the polymer having thiazolyl moiety more selective than that containing imidazolyl or pyridinyl moieties. Ion selectivity of poly[N‐(benzo[d]thiazol‐2‐yl)acrylamide] showed higher selectivity to many ions e.g. Fe³⁺, Pb²⁺, Cd²⁺, Ni²⁺, and Cu²⁺. While, that of poly[N‐(pyridin‐4‐yl)acrylamide] is found to be high selective to Fe³⁺ and Cu²⁺ only. Energy dispersive spectroscopy measurements, morphology of the polymers and their metallopolymer complexes, thermal analysis and antimicrobial activity were studied. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42712.     

Microwave preparation and properties of O-crosslinked maleic acyl chitosan adsorbent for Pb2+ and Cu2+

A novel chitosan-based adsorbent (CCTM) was prepared by the reaction of epichlorohydrin O-crosslinked chitosan with maleic anhydride under microwave irradiation. The chemical structure of this polymer was characterized by infrared spectroscopy and X-ray diffraction analyses. The effects of various variables such as degree of substitution, adsorption time, initial metal ion concentration, solution pH, and temperature, on the adsorption of Pb²⁺ and Cu²⁺ by CCTM were investigated. The results demonstrate that the microwave irradiation can remarkably enhance the reaction. CCTM has higher adsorption capacity than chitosan. The maximum adsorption capacities for Pb²⁺ and Cu²⁺, with initial concentrations of 0.02 mol L⁻¹ at pH 5, are 246.3 and 132.5 mg g⁻¹, respectively. The adsorbent can be recycled. These results have important implications for the design of effective chitosan-based adsorbents in the removal of heavy metal ions from wastewaters. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Optimization of parameters for competitive adsorption of heavy metal ions (Pb+2, Ni+2, Cd+2) onto activated carbon

This study investigates optimization of various competitive adsorption parameters for removal of Cd(II), Ni(II) and Pb(II) from aqueous solutions by commercial activated carbon (AC) using the Taguchi method. Adsorption parameters such as initial metal concentration of each metal ion (C_0,i ), initial pH (pH₀), adsorbent dosage (m) and contact time (t) in batch technique were studied to observe their effects on the total adsorption capacity of metals onto activated carbon (q _tot ). The adsorbent dosage has been found to be the most significant parameter. Interactions between C_0,Cd ×C_0,Ni , C_0,Cd ×C_0,Pb and C_0,Ni ×C_0,Pb have been considered for simultaneous metal ions adsorption. The optimum condition for adsorption of metal ions were obtained with C_0,i =100 mg L^?1, pH₀=7, m=2 g L^?1 and t=80 min. Finally, experimental results showed that a multi-staged adsorptive treatment would be necessary to reach the minimal discharge standards of metal ions in the effluent.     

The competitive heavy metal removal by hydroxyethyl cellulose-g-poly(acrylic acid) copolymer and its sodium salt: The effect of copper content on the adsorption capacity

Summary Crosslinked hydroxyethyl cellulose-g-poly(acrylic acid) (HEC-g-pAA) graft copolymer was prepared by grafting of acrylic acid (AA) onto hydroxyethyl cellulose (HEC) using [Ce(NH₄)₂(NO₃)₆]/HNO₃ initiator system in the presence of poly(ethyleneglycol diacrylate) (PEGDA) crosslinking agent in 1:1 (v/v) mixture of methanol and water at 30 °C. Carboxyl content of copolymer was determined by neutralization of –COOH groups with NaOH solution and sodium salt of copolymer (HEC-g-pAANa) was swelled in distilled water in order to determine the equilibrium swelling value of copolymer. Both dry HEC-g-pAA and swollen HEC-g-pAANa copolymers were used in the heavy metal ion removal from three different aqueous ion solutions as follows: a binary ion solution with equal molar contents of Pb²⁺and Cd²⁺, a triple ion solution with equal molar contents of Pb²⁺, Cu²⁺ and Cd²⁺, and a triple ion solution with twice Cu²⁺molar contents of Pb²⁺and Cd²⁺. Higher removal values on swollen HEC-g-pAANa were observed in comparison to those on dry polymer. The presence of Cu²⁺decreased the adsorption values for Pb²⁺ and Cd²⁺ ions on both types of HEC copolymer. However, with further increase in Cu²⁺ content both dry and swollen copolymers became apparently selective to Cu²⁺ removal and Cu²⁺ removal values exceeded the sum of adsorption values for Pb²⁺ and Cd²⁺. Maximum metal ion removal capacities were 1.79 and 0.85 mmol Me²⁺/g_polymer on swollen HEC-g-pAANa and dry HEC-g-pAA, respectively.     

Reusability and selective adsorption of Pb<Superscript>2+</Superscript> on chitosan/P(2-acrylamido-2-methyl-1-propanesulfonic acid-<Emphasis Type="Italic">co</Emphasis>-acrylic acid) hydrogel

Reusability and selective adsorption toward Pb²⁺ with the coexistence of Cd²⁺, Co²⁺, Cu²⁺ and Ni²⁺ ions on chitosan/P(2-acrylamido-2-methyl-1-propanesulfonic acid-co-acrylic acid) [CS/P(AMPS-co-AA)] hydrogel, a multi-functionalized adsorbent containing –NH₂, –OH, –COOH and –SO₃H groups was studied. The CS/P(AMPS-co-AA) was prepared in aqueous solution by a simple one-step procedure using glow discharge electrolysis plasma technique. The reusability of adsorbent in HNO₃, EDTA-2Na and EDTA-4Na was investigated in detail. The competitive adsorption of the metal ions at the initial stage was compared between their equal mass concentration and equal molar concentration. In addition, the adsorption mechanism of the adsorbent for adsorption of Pb²⁺ was also analyzed by XPS. The results showed that the optimum pH of adsorption was 4.8, and time of adsorption equilibrium was about 180 min. Adsorption kinetics fitted well in the pseudo second-order model. The equilibrium adsorption capacities of Pb²⁺, Cd²⁺, Co²⁺, Cu²⁺, and Ni²⁺ at pH 4.8 were obtained as 673.3, 358.3, 176.7, 235.0 and 171.7 mg g^?1, in their given order. The adsorbent displayed an excellent reusability using 0.015 mol L^?1 EDTA-4Na solution as the eluent, and the desorption ratio could not correctly reflect the true characteristics of adsorption/desorption process. Moreover, the adsorbent showed good adsorption selectivity for Pb²⁺. The molar adsorption capacity at the initial stage with equal molar concentration was more reliable than the mass adsorption capacity during the study of selective adsorption. According to the XPS results, the adsorption of Pb²⁺ ions by the CS/P(AMPS-co-AA) absorbent could be attributed to the coordination between N atom and Pb²⁺ and ion-exchange between Na⁺ and Pb²⁺.     

Synthesis of magnetic Fe3O4@SiO2-(-NH2/-COOH) nanoparticles and their application for the removal of heavy metals from wastewater

In this work, Fe₃O₄@SiO₂-(-NH₂/-COOH) nanoparticles were synthesized for the removal of Cd²⁺, Pb²⁺ and Zn²⁺ ions from wastewater. The results of characterization showed that Fe₃O₄@SiO₂-(-NH₂/-COOH) was superparamagnetic with a core–shell structure. The surface of Fe3O4 was successfully coated with silica and modified with amino groups and carboxyl groups through the use of a silane coupling agent, polyacrylamide and polyacrylic acid. The dispersion of the particles was improved, and the surface area of the Fe3O4@SiO2-(-NH2/-COOH) nanoparticles was 67.8 m²/g. The capacity of Fe₃O₄@SiO₂-(-NH₂/-COOH) to adsorb the three heavy metals was in the order Pb²⁺ > Cd²⁺ > Zn²⁺, and the optimal adsorption conditions were an adsorption dose of 0.8 g/L, a temperature of 30°C and concentrations of Pb²⁺, Cd²⁺ and Zn²⁺ below 120, 80 and 20 mg/L, respectively. The maximum adsorption capacities for Pb²⁺, Cd²⁺ and Zn²⁺ were 166.67, 84.03 and 80.43 mg/g. The adsorption kinetics followed a pseudo-second-order model and Langmuir isotherm model adequately depicted the isotherm adsorption process. Thermodynamic analysis showed that the adsorption of the three metal ions was an endothermic process and that increasing the temperature was conducive to this adsorption.     

Preparation of thiourea functionalized polyvinyl alcohol‐coated magnetic nanoparticles and their application in Pb2+ ions adsorption

We have prepared a novel kind of magnetic nanoparticle with high adsorption capacity and good selectivity for Pb²⁺ ions by modifying the magnetic nanoparticles with polyvinyl alcohol (PVA) and thiourea. The resultant magnetic nanoparticles were used to adsorb Pb²⁺ ions from aqueous solution. The influence of the solution pH, the adsorption time, the adsorption temperature, coexisting ions, and the initial concentration of Pb²⁺ ions on the adsorption of Pb²⁺ ions were investigated. The results indicated that Pb²⁺ ions adsorption was an endothermic reaction, and adsorption equilibrium was achieved within 30 min. The optimal pH for the adsorption of Pb²⁺ ions was pH 5.5, and the maximum adsorption capacity of Pb²⁺ ions was found to be 220 mg/g. Moreover, the coexisting cations such as Ca²⁺, Co²⁺, and Ni²⁺ had little effect on adsorption of Pb²⁺ ions. The regeneration studies showed that thiourea functionalized PVA‐coated magnetic nanoparticles could be reused for the adsorption of Pb²⁺ ions from aqueous solutions over five cycles without remarkable change in the adsorption capacity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40777.     

Poly (methacrylic acid) modified biomass for enhancement adsorption of Pb2+, Cd2+ and Cu2+

In this study, the graft copolymerization of methacrylic acid onto the biomass of baker's yeast was carried out in aqueous medium using potassium persulfate (PPS) as initiator. The poly (methacrylic acid) modified biomass obtained was characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS) and microscopic analyses. The number of functional groups was determined by potentiometric titration. The adsorption capacity of the modified biomass for Pb²⁺, Cd²⁺ and Cu²⁺ showed a significant increase compared with the pristine biomass, due to the presence of a large number of functional groups. According to the Langmuir equation, the maximum uptake capacities (q_m) for Pb²⁺, Cd²⁺ and Cu²⁺ were 243.9, 108.7 and 73.5 mg g^?1, respectively. Adsorption kinetics study showed that completion of the adsorption process needed only 30 min. The loaded biosorbent was regenerated using EDTA solution and used repeatedly three times with little loss of uptake capacity. Good results were obtained when the modified biomass was used to treat simulated wastewater containing Pb²⁺, Cd²⁺ and Cu²⁺. Copyright © 2007 Society of Chemical Industry     

Ligating behavior and metal uptake of N‐sulphonylpolyamine chelating resins anchored on polystyrene‐divinylbenzene beads

Amberlite XAD‐2 has been functionalized by coupling through –SO₂‐with ethylenediamine, propylenediamine, and diethylenetriamine to give the corresponding polyamine chelating resins I–III. The solid metallopolymer complexes of the synthesized chelating resins with Cu²⁺, Zn²⁺, Cd²⁺, and Pb²⁺ were synthesized. The polyamine derivatives and their metal complexes were characterized by elemental analysis, spectral (IR, UV/V, and ESR), and magnetic studies. The batch equilibrium method was utilized for using the chelating polyamines for the removal of Cu⁺², Zn⁺², Cd⁺², and Pb⁺² ions from aqueous solutions at different pH values and different shaking times at room temperature. The selective extraction of Cu⁺² from a mixture of the four metal ions and the metal capacities of the chelating resins were evaluated using atomic absorption spectroscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1839–1846, 2005     

Process Design of Groundnut Husk Waste for Pb2+ and Cd2+ Ions Mitigation in Drinking Water Purification

This present work has explored a novel application of modified Arachis hypogaea (groundnut) husk on mitigation of toxic Pb²⁺ and Cd²⁺ ions in aqueous phase. Ecotoxicological assessment of exhausted adsorbent was investigated as per standard OECD guidelines. Standard deviation, correlation coefficient, and the reduced chi square test were evaluated and compared statistically on experimental data. The results showed good sorption capacities—31.62 and 29.78 mg g^?l for Pb²⁺ and Cd²⁺ ions, respectively. Pseudo first-order rate kinetics was well correlated for Pb²⁺ and Cd²⁺ ions sorption over all kinetic models. The sorption data was in good agreement with the Freundlich isotherm for Pb²⁺ and the Sips model for Cd²⁺ ions sorption. The sorption capacity was endothermic in nature. Pb²⁺ ions desorption was three times faster than Cd²⁺ ions. The sorption mechanism was plausibly explained by spectroscopic techniques. Herein, the tailored abundant agro-waste material is a competitive sorbent and may be exploited in decontamination of metal ions in a wide range of concentrations. Supplemental materials are available for this article. Go to the publisher's online edition of Separation Science and Technology to view the free supplemental file.