Adsorption of Pb(II) and Ni(II) From Aqueous Solution by a High-Capacity Industrial Sewage Sludge-Based Adsorbent

In the present study, adsorption of Ni(II) and Pb(II) from aqueous solution was investigated using activated carbon synthesized with industrial wastewater sludge. The synthesized adsorbent was analyzed using nitrogen adsorption–desorption and Fourier transfer infrared (FTIR) techniques. Batch adsorption mode was used to evaluate the effect of solution pH, contact time, adsorbent dose, initial metal ion concentration, and temperature on the adsorption capacity of the synthesized adsorbent. The kinetic data were analyzed using different kinetic models. The pseudo-second-order equation gave the best fit to the experimental data for both metal ions. The equilibrium isotherm data were analyzed using the Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) isotherm models. The results showed that the data obtained for the Ni(II) and Pb(II) adsorption are in good agreement with the Langmuir model. The Langmuir mono-layer maximum adsorption capacities for Ni(II) and Pb(II) ions were estimated to be 74.06 and 88.76 mg g^?1 at 25°C, respectively. In addition, the thermodynamic studies proved that the adsorption process of both metals could be considered endothermic.     

Removal of Cd(II), Cu(II), and Pb(II) by adsorption onto natural clay: a kinetic and thermodynamic study

In this work, we study the elimination of three bivalent metal ions (Cd²⁺, Cu²⁺, and Pb²⁺) by adsorption onto natural illitic clay (AM) collected from Marrakech region in Morocco. The characterization of the adsorbent was carried out by X-ray fluorescence, Fourier transform infrared spectroscopy and X-ray diffraction. The influence of physicochemical parameters on the clay adsorption capacity for ions Cd²⁺, Cu²⁺, and Pb²⁺, namely the adsorbent dose, the contact time, the initial pH imposed on the aqueous solution, the initial concentration of the metal solution and the temperature, was studied. The adsorption process is evaluated by different kinetic models such as the pseudo-first-order, pseudo-second-order, and Elovich. The adsorption mechanism was determined by the use of adsorption isotherms such as Langmuir, Freundlich, and Temkin models. Experiments have shown that heavy metals adsorption kinetics onto clay follows the same order, the pseudo-second order. The isotherms of adsorption of metal cations by AM clay are satisfactorily described by the Langmuir model and the maximum adsorption capacities obtained from the natural clay, using the Langmuir isotherm model equation, are 5.25, 13.41, and 15.90 mg/g, respectively for Cd(II), Cu(II), and Pb(II) ions. Adsorption of heavy metals on clay is a spontaneous and endothermic process characterized by a disorder of the medium. The values of ΔH are greater than 40 kJ/mol, which means that the interactions between clay and heavy metals are chemical in nature.     

Kinetics and equilibrium adsorption study of lead(II) onto activated carbon prepared from coconut shell

Removal of lead from aqueous solutions by adsorption onto coconut-shell carbon was investigated. Batch adsorption experiments were performed to find out the effective lead removal at different metal ion concentrations. Adsorption of Pb2+ ion was strongly affected by pH. The coconut-shell carbon (CSC) exhibited the highest lead adsorption capacity at pH 4.5. Isotherms for the adsorption of lead on CSC were developed and the equilibrium data fitted well to the Langmuir, Freundlich, and Tempkin isotherm models. At pH 4.5, the maximum lead adsorption capacity of CSC estimated with the Langmuir model was 26.50 mg g(-1) adsorbent. Energy of activation (Ea) and thermodynamic parameters such as DeltaG, DeltaH, and DeltaS were evaluated by applying the Arrhenius and van't Hoff equations. The thermodynamics of Pb(II) on CSC indicates the spontaneous and endothermic nature of adsorption. Quantitative desorption of Pb(II) from CSC was found to be 75% which facilitates the sorption of metal by ion exchange.     

Efficient Removal of Pb(II) from Aqueous Medium Using Chemically Modified Silica Monolith

The adsorptive removal of lead (II) from aqueous medium was carried out by chemically modified silica monolith particles. Porous silica monolith particles were prepared by the sol-gel method and their surface modification was carried out using trimethoxy silyl propyl urea (TSPU) to prepare inorganic–organic hybrid adsorbent. The resultant adsorbent was evaluated for the removal of lead (Pb) from aqueous medium. The effect of pH, adsorbent dose, metal ion concentration and adsorption time was determined. It was found that the optimum conditions for adsorption of lead (Pb) were pH 5, adsorbent dose of 0.4 g/L, Pb(II) ions concentration of 500 mg/L and adsorption time of 1 h. The adsorbent chemically modified SM was characterized by scanning electron microscopy (SEM), BET/BJH and thermo gravimetric analysis (TGA). The percent adsorption of Pb(II) onto chemically modified silica monolith particles was 98%. An isotherm study showed that the adsorption data of Pb(II) onto chemically modified SM was fully fitted with the Freundlich and Langmuir isotherm models. It was found from kinetic study that the adsorption of Pb(II) followed a pseudo second-order model. Moreover, thermodynamic study suggests that the adsorption of Pb(II) is spontaneous and exothermic. The adsorption capacity of chemically modified SM for Pb(II) ions was 792 mg/g which is quite high as compared to the traditional adsorbents. The adsorbent chemically modified SM was regenerated, used again three times for the adsorption of Pb(II) ions and it was found that the adsorption capacity of the regenerated adsorbent was only dropped by 7%. Due to high adsorption capacity chemically modified silica monolith particles could be used as an effective adsorbent for the removal of heavy metals from wastewater.     

Determination of lead separated selectively with ion exchange method from solution onto BCW in Sirnak, East Anatolia of Turkey

There are approximately 82 million of tons asphaltites reserves in ?irnak, East Anatolia of Turkey. The present study was investigated to employ ashes of S?rnak BCW (burned coal waste) as an ion exchange in removal of important toxic metal, Lead (Pb), in high yields by adsorption. The ion exchange characteristics of lead onto BCW from aqueous solution were investigated with respect to the changes in pH of solution, adsorbent dosage, initial metal ion concentration, contact time and temperature of solution. For the adsorption of lead, the Langmuir isotherm model fitted to equilibrium data better than the Freundlich isotherm model. Thermodynamic functions, the change of free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) of adsorption were also calculated for lead. These parameters showed that the adsorption was feasible, spontaneous and exothermic at 293–333 K. Experimental data were also evaluated in terms of kinetic characteristics of adsorption. The batch kinetic data were correlated to the pseudo-first order and pseudo-second order models. The data fitted better to the pseudo-second order equation. The activation energy of systems was determined. Experimental data have shown that BCW that was used in unmodified form; as low cost, readily available ion exchange; can be used for removal of lead from industrial waste waters. Analysis was determined using Flame Atomic Absorption Spectrometry (FAAS).     

改性生物凝胶对重金属离子的吸附性能研究

以桔子汁加工残渣为原料,制备钙型和氢型生物凝胶作为吸附剂,用于去除水溶液中的重金属离子.结果表明,上述凝胶在水溶液中稳定性较好,对重金属离子的吸附性能优良.钙型凝胶的吸附选择性顺序为:Fe3 ＞Pb2 ＞Cd2 ＞Zn2 ,饱和吸附容量分别为:Pb2 、Cd2 、Zn2 均为约1.1mmol/g、Fe3 为1.5mmol/g;氢型凝胶的吸附选择性顺序为:Pb2 ＞Zn2 ＞Cd2 .钙型凝胶对Fe3 的吸附行为明显不同于氢型凝胶,钙型凝胶以离子交换机理以及Fe3 与Ca2 之间的共沉淀作用为主;而氢型凝胶对Fe3 的吸附则以离子交换机理为主.     

Synthesis and Application of Co‐Poly(2‐hydroxyethyl methacrylate‐ethylene dimethacrylate) Coupled with Alizarin Yellow for Preconcentration and Determination of Lead in Water Samples by Flame Atomic Absorption Spectrometry

Poly(2‐hydroxyethyl methacrylate‐ethylene dimethacrylate) (PHEMA‐EDMA) beads were produced by free radical co‐polymerization of 2‐hydroxyethyl methacrylate (HEMA) and ethylene dimethacrylate (EDMA). Then, metal complexing ligand alizarin yellow was covalently attached onto PHEMA‐EDMA beads. The resulting resin has been characterized by FT‐IR and studied for the preconcentration and determination of trace Pb(II) ion from solution samples. The optimum pH value for sorption of the metal ion was 5. The sorption capacity of functionalized resin is 100 mg.g^‐1. The chelating resin can be reused for 20 cycles of sorption‐desorption without any significant change in sorption capacity. A recovery of 96% was obtained for the metal ion with 0.1 M nitric acid as eluting agent. The equilibrium adsorption data of Pb(II) on modified resin were analyzed by Langmuir and Freundlich models. Based on equilibrium adsorption data the Langmuir and Freundlich constants were determined 2.571 and 418.7 at pH 5 and 25 °C. The method was applied for lead ions determination from well water sample.     

Comparative Adsorption of Lead(II) on Flake and Bead‐Types of Chitosan

The adsorption of Pb(II) ions from aqueous solutions by chitosan flakes and beads was studied. The chitosan beads were prepared by casting an acidic chitosan solution into alkaline solution. Experiments were carried out as a function of pH, agitation period and initial concentration of Pb²⁺ ions. The uptake of Pb²⁺ ions from aqueous solution was determined from changes in concentration as measured by atomic absorption spectroscopy. The maximum uptake of Pb²⁺ ions on chitosan beads was greater than that on chitosan flakes. Adsorption isothermal data could be interpreted by the Langmuir equation. The experimental data of the adsorption equilibrium from Pb²⁺ ion solutions correlated well with the Langmuir isotherm equation. SEM analyses were also conducted for visual examination of the chitosan flakes and beads. Physical properties including surface area and average pore diameter were characterized by N₂ adsorption experiment.     

Poly-L-Histidine Attached Poly(glycidyl methacrylate) Cryogels for Heavy Metal Removal

Poly-L-histidine immobilized poly(glycidyl methacrylate) (PGMA) cryogel discs were used for the removal of heavy metal ions [Pb(II), Cd(II), Zn(II) and Cu(II)] from aqueous solutions. In the first step, PGMA cryogel discs were synthesized using glycidyl methacrylate (GMA) as a basic monomer and methylene bisacrylamide (MBAAm) as a cross linker in order to introduce active epoxy groups through the polymeric backbone. Then, the metal chelating groups are incorporated to cryogel discs by immobilizing poly-L-histidine (mol wt ≥ 5000) having poly-imidazole ring. The swelling test, fourier transform infrared spectroscopy and scanning electron microscopy were performed to characterize both the PGMA and poly-L-histidine immobilized PGMA [P-His@PGMA] cryogel discs. The effects of the metal ion concentration and pH on the adsorption capacity were studied. These parameters were varied between 3.0–6.0 and 10–800 mg/L for pH and metal ion concentration, respectively. The maximum adsorption capacity of heavy metal ions of P-His@PGMA cryogel discs were 6.9 mg/g for Pb(II), 6.4 mg/g for Cd(II), 5.6 mg/g for Cu(II) and 4.3 mg/g for > Zn(II). Desorption of heavy metal ions was studied with 0.1 M HNO₃ solution. It was observed that cryogel discs could be recurrently used without important loss in the adsorption amount after five repetitive adsorption/desorption processes. Adsorption isotherms were fitted to Langmuir model and adsorption kinetics were suited to pseudo-second order model. Thermodynamic parameters (i.e. ΔH° ΔS°, ΔG°) were also calculated at different temperatures.     

Carboxyl-functionalized nanoparticles with magnetic core and mesopore carbon shell as adsorbents for the removal of heavy metal ions from aqueous solution

This communication demonstrates superparamagnetic nanosized particles with a magnetic core and a porous carbon shell (thickness of 11 nm), which can remove 97% of Pb(2+) ions from an acidic aqueous solution at a Pb(2+) ion concentration of 100 mg L(-1). It is suggested that a weak electrostatic force of attraction between the heavy metal ions and the nanoparticles and the heavy metal ions adsorption on the mesopore carbon shell contribute most to the superior removal property.     

Adsorption of some bivalent heavy metal ions from aqueous solutions by manganese nodule leached residues

The leached residue, generated after selective extraction of Cu, Ni, and Co in sulfur dioxide-ammonia leaching of manganese nodules, was characterized and batch isothermal adsorption experiments were conducted at ambient temperature to evaluate the effectiveness of the water-washed leached residue for removal of different bivalent metal ions from aqueous synthetic solutions. The effects of pH, initial metal ion concentrations, amount of adsorbent, interfering ions, and heat treatment were also investigated. The uptake of metal ions increased with increasing pH. Under identical conditions the adsorption capacity increased in the order Cd(2+)相似文献   

Adsorption of heavy metal ions onto dithizone-anchored poly (EGDMA-HEMA) microbeads

The dithizone-anchored poly (EGDMA-HEMA) microbeads were prepared for the removal of heavy metal ions (i.e. cadmium, mercury, chromium and lead) from aqueous media containing different amounts of these ions (25-500 ppm) and at different pH values (2.0-8.0). The maximum adsorptions of heavy metal ions onto the dithizone-anchored microbeads from their solutions was 18.3, Cd(II); 43.1, Hg(II); 62.2, Cr(III) and 155.2 mg g(-1) for Pb(II). Competition between heavy metal ions (in the case of adsorption from mixture) yielded adsorption capacities of 9.7, Cd(II); 28.7, Hg(II); 17.6, Cr(III) and 38.3 mg g(-1) for Pb(II). The same affinity order was observed under non-competitive and competitive adsorption, i.e. Cr(III)>Pb(II)>Hg(II)>Cd(II). The adsorption of heavy metal ions increased with increasing pH and reached a plateaue value at around pH 5.0. Heavy metal ion adsorption from artificial wastewater was also studied. The adsorption capacities are 4.3, Cd(II); 13.2, Hg(II); 7.2, Cr(III) and 16.4 mg g(-1) for Pb(II). Desorption of heavy metal ions was achieved using 0.1 M HNO(3). The dithizone-anchored microbeads are suitable for repeated use (for more than five cycles) without noticeable loss of capacity.     

Efficiency of Acacia Gummifera powder as biosorbent for simultaneous decontamination of water polluted with metals

Biosorbent materials represent an interesting alternative to classic methods of metal removal from industrial effluents. Acacia biomass showed a higher absorption capacity for heavy metals than living biomass. This study aimed to evaluate the bioadsorption of Lead and Cadmium onto Acacia Gummifera gum, using batch experiment. The structural characterization of the biosorbent was carried out using FT-IR, SEM, BET, TGA and DSC analysis. The adsorption equilibrium was reached within 15 min. A maximum uptake of 18.3 mg.g⁻¹ Pb²⁺ and 9.57 mg.g⁻¹ Cd²⁺ was achieved at pH 6.5. The metal ions seemed to be removed exclusively by ion exchange, physical sorption and chelation. The biomass of A. Gummifera powder was found to be effective for lead and cadmium removal with respectively 97% and 86% sorption efficiency at a concentration of 100 mg/L, in aqueous media. Parameters affecting adsorption capacities such as biosorbent dosage, initial metal concentration, temperature, and pH are discussed in detail. Furthermore, adsorption thermodynamics, kinetics, and equilibrium were studied and fitted by different models. Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms were used to compare adsorption data at equilibrium. The adsorption kinetics data were found to be best fitted by the pseudo-second-order model, and the adsorption isotherm was well fitted with the Langmuir model. The calculated thermodynamic parameters (ΔG⁰, ΔS⁰ and ΔH⁰) indicated a spontaneous and exothermic biosorption of both metal ions onto Acacia Gummifera. Moreover, chromatograms obtained by size exclusion chromatography coupled with multi-angle laser light scattering detection system (SECMALLS) showed the formation of complexes between the arabinogalactan-peptide (AGP) and glycoprotein (GP) Acacia moieties and the two studied metal ions. The analysis of the FTIR spectra of dried Acacia and that of Acacia loaded with lead and cadmium in aqueous media suggests that the surface functional groups such as amides and carboxy groups might be involved in the metal removal process.The extent of adsorption for both metals increased along with an increase of the A. Gummifera biomass dosage. A. Gummifera biomass, which is safe, of low-cost, and highly selective, seems therefore to be a promising substrate for simultaneous trapping of Pd and Cd ions in aqueous solutions.     

Adsorption of copper(II), cadmium(II), nickel(II) and lead(II) from aqueous solution using biosorbents

Three types of agricultural waste, citrus maxima peel (CM), passion fruit shell (PF) and sugarcane bagasse (SB), were used to produce biosorbents for removing the heavy metal ions of copper(II), cadmium(II), nickel(II) and lead(II) from a pH 5.0 solution. The properties of biosorbents were characterized using scanning electron microscopy (SEM), zeta potential analyzer, Fourier transform infrared (FTIR) spectroscopy, elemental analyzer and tests of cation exchange capacity (CEC). The result indicated that the selected biosorbents possess rich carboxyl (COOH) and hydroxyl (OH) groups to produce a complexation with the heavy metals. Moreover, the negative surface charge of the biosorbent might adsorb the metal ions through the ion exchange. All of the adsorption isotherms indicated that L-type characters represented complexation and ion exchanges that were the adsorption mechanisms of biosorbents toward heavy metals. Biosorbents with higher oxygen content might generate high adsorption capacities. The adsorption capacities of CM and PF, estimated from the fitting to the Langmuir isotherm, are similar to those reported by others regarding biosorbents.     

Adsorption of cadmium and lead from palm oil mill effluent using bone-composite: optimisation and isotherm studies

The adsorption of Cd and Pb ions from palm oil mill effluent on a mesoporous-activated cow bone composite powder has been investigated. Adsorbent was developed from cow bones, coconut shells and zeolite. The composite examined in the present work has a BET surface area of 248.398 m²/g. The optimisation of the removal efficiency of the heavy metals was investigated using central composite design and analysed using response surface methodology. The analysis of variance of the quadratic model signified that the model suitably predicted the uptake of the heavy metal ions at a 95% confidence level. The optimal operating condition was recorded at pH 4, 50 rpm, within 24 h and 1 mm of particle size and 12.5 gL^?1 of adsorbent dosage. The characteristics of the composite were investigated using the Fourier transform irradiation. The morphology and chemical composition of composite was examined using the scanning electron microscopy equipped with energy dispersive x-ray. Characterisation study was conducted before and after the adsorption process. The results obtained illustrated that the removal of cadmium and lead from POME was influenced by the functional groups available on the surface of the composite. The carboxyl and hydroxyl groups are mainly responsible for the removal of cadmium and lead through chelating process. The point of zero charge (pH_pzc) revealed that the adsorbent contained acidic sites with negatively charge surface which influenced the adsorption process. The experimental data of the heavy metals of Cd and Pb investigated were fitted to the Langmuir and Freundlich models. The result revealed that the adsorption equilibrium data fitted better to the Langmuir model for the adsorption Cd and to the Freundlich model for the adsorption of Pb.     

微囊化海藻酸离子移变凝胶的制备、结构与性能

通过静电脉冲技术制备了海藻酸-壳聚糖-海藻酸(Alginate-Chitosan-Alginate,ACA)微胶囊,红外光谱分析表明,ACA是一种以聚电解质配合物为囊膜,以海藻酸钠离子吸附剂为囊心物的微胶囊型离子吸附体系.扫描电镜测试表明,ACA吸附重金属离子的过程是微胶囊囊内海藻酸凝胶化的过程,其解吸附过程是海藻酸凝胶转变成海藻酸溶液的过程.与传统离子交换树脂相比,ACA对Pb²⁺的吸附具有较高的去除率、很强的富集能力和较低的极限吸附浓度,并且能够被多次重复使用.ACA的离子交换速率比传统离子交换树脂快得多,离子交换过程中,交换离子和吸附剂海藻酸分子的相互扩散大大提高了离子交换速率.     

Efficient Adsorption and Recovery of Pb(II) from Aqueous Solution by a Granular pH-Sensitive Chitosan-based Semi-IPN Hydrogel

A series of granular pH-sensitive semi-interpenetrating polymer network (semi-IPN) hydrogels based on chitosan (CTS), acrylic acid (AA) and gelatine (GE) were utilized for the adsorption and recycle of Pb(II) from aqueous solutions. The composite hydrogels have been characterized by FT-IR and TGA. The effects of contact time, pH value and initial Pb(II) concentration on the adsorption were investigated. Results indicated that the adsorption capacity of the hydrogel increased with increasing pH value and initial Pb(II) concentration, and a pH-sensitive adsorption characteristic was presented. The adsorption rate of the semi-IPN hydrogels on Pb(II) is fast with an adsorption rate constant of 14.9790 mg/(g·s), and adsorption equilibrium could be reached within 10 min. The adsorption isotherms of the hydrogels for Pb(II) could be described well by the Langmuir equation, rather than the Freundlich equation. The as-prepared hydrogels showed good reusability with 0.05 mol/l HNO₃ solutions as the desorbing agent and 0.1 mol/l NaOH solutions as the regeneration agent, respectively. After five consecutive adsorption-desorption processes, the semi-IPN hydrogel with 20 wt% GE may reach 85.26% of its initial adsorption capacity. In addition, the adsorbed Pb(II) can be quantitatively recovered by simply eluting the hydrogel with dilute HNO₃ solution, and a recovery ratio of 89.27% was reached for the semi-IPN hydrogel. The satisfactory adsorption amount is mainly derived from the chelating of functional groups (i.e. –COO^? and –NH₂) with Pb(II) ions. The hydrogel adsorbents exhibited excellent affinity for Pb(II), and can be applied to treat wastewater containing heavy metal ion and simultaneously recover the valuable metal sources.     

Use of Biopolymers for the Removal of Metal Ion Contaminants from Water

Summary: Naturally abundant biosorbants such as chitin and chitosan are recognized as excellent metal ligands, forming stable complexes with many metal ions, and serving as effective protein coagulating agents. Chitosan is a heteropolymer made of D-glucosamine and a small fraction of N-acetyl-D-glucosamine residues. Therefore, the adsorption ability of chitosan is found to be much higher than that of chitin, which has relatively fewer amino groups. Zeolites are crystalline microporous aluminosilicates with ion exchange properties suitable for a wide range of applications in catalysis and separation of liquid and gaseous mixtures. Incorporation in chitosan membranes is an effective method to control the diffusion outside the zeolite crystals and appropriately designed composite systems can find numerous opportunities for applications in wastewater treatment. In this paper we present the synthesis of zeolite-chitosan and zeolite-ethyl cellulose composites by encapsulation of clinoptilolite using a gelling solution of chitosan or an ethyl cellulose solution in ethyl acetate. The adsorption process of Cu²⁺ and Cd²⁺ on some adsorbents was investigated: clinoptillolite tuff (0.05 mm), chitosan flakes, ethyl cellulose, zeolite-chitosan and zeolite- ethyl cellulose composites. Zeolite-chitosan composites have been prepared by encapsulation of zeolites by a gelling solution of chitosan. Micrometric crystals of clinoptillolite were dispersed in a 3% chitosan solution in 1% aqueous acetic acid. The chitosan gel was formed and the zeolite crystals were encapsulated during the gelling process. The same procedure was used to obtain zeolite – ethyl cellulose composites. Study of the metal ion retention properties of different adsorbent materials was carried out using a steady state regime. The concentration of heavy metal ions in supernatant was determined by the atomic absorption spectrophotometric method. Adsorption isotherms of metal ions on adsorbents were determined and correlated with common isotherm equations such as Langmuir and Freundlich models.     

Removal of Lead by Merlinoite Prepared from Sugarcane Bagasse Ash and Kaolin: Synthesis,Isotherm, Kinetic,and Thermodynamic Studies

This study introduces a merlinoite synthesized from sugarcane bagasse ash (SBA) and kaolin and evaluates its application as an adsorbent to remove lead from wastewater. The synthesis was performed via the hydrothermal method, and optimal conditions were determined. The adsorption of Pb by merlinoite was also optimized. Determination of the Pb²⁺ remaining in the aqueous solution was determined by atomic absorption spectroscopy (AAS). Adsorption isotherms were mainly studied using the Langmuir and Freundlich models. The Langmuir model showed the highest consistency for Pb adsorption on merlinoite, yielding a high correlation coefficient (R²) of 0.9997 and a maximum adsorption capacity (q_max) of 322.58 mg/g. The kinetics of the adsorption process were best described by a pseudo-second-order model. Thermodynamic studies carried out at different temperatures established that the adsorption reaction was spontaneous and endothermic. The results of this study show that merlinoite synthesized from kaolinite and SBA is an excellent candidate for utilization as a high-performance adsorbent for lead removal from wastewater.     

Biosorption of Co(II), Cr(III), Cd(II), and Pb(II) Ions from Aqueous Solution Using Nonliving Neochloris Pseudoalveolaris Deason & Bold: Equilibrium,Thermodynamic, and Kinetic Study

In this study, biosorption of cobalt(II), chromium(III), cadmium(II), and lead(II) ions from aqueous solution was studied using the algae nonliving biomass (Neochloris pseudoalveolaris, Np) as natural and biological sorbents. The effect of pH, contact time, temperature, and metal concentration on the adsorption capacity of metal ions was investigated. The maximum adsorption capacities for Co(II), Cr(II), Cd(II), and Pb(II) were found to be 20.1, 9.73, 51.4 and 96.2 mg/g at the optimum conditions, respectively. The experiments showed that when pH increased, an increase in the adsorption capacity of the biomass was observed too. The kinetic results of adsorption obeyed a pseudo second-order model. Freundlich and Langmuir isotherm models were applied to experimental equilibrium data of metal ions adsorption and the value of R _L for Pb(II), Cb,(II), Co(II), and Cr(III) was found to be 0.376, 0271, 0872, and 096, respectively. The thermodynamic parameters related to the adsorption process such as E _a , ΔG ⁰, ΔH ⁰, and ΔS ⁰ were calculated. ΔH ⁰ values (positive) showed that the adsorption mechanism was endothermic. Weber-Morris and Urano-Tachikawa diffusion models were also applied to experimental equilibrium data. The algae biomass was effectively used as a sorbent for the removal of metal ions from aqueous solutions.