Adsorbent For Removal Of Copper Research Articles

Adsorptive removal of copper (II) and lead (II) using chitosan-g-maleic anhydride-g-methacrylic acid copolymer

In the present work, the maleic anhydride and methacrylic acid monomers were grafted one after another onto chitosan by using ceric ammonium nitrate as the initiator. The optimum conditions for grafting were studied by varying the initiator concentration, monomer concentration and reaction temperature. The synthesized grafted samples were subjected to various analytical techniques such as FTIR, XRD, TGA and DSC methods The proof of formation of graft copolymer was ascertained from the results of FTIR analysis and XRD studies. The TGA and DSC results conclude the highly thermally stable behavior of the prepared graft copolymer sample. The prepared graft copolymer was utilized for removing copper and lead from aqueous solutions and optimum adsorption parameters were evaluated under various pH, adsorbent dose, contact time and initial metal ion concentration. The adsorption and kinetic studies have been explained by Langmuir, Freundlich and pseudo − first order, second order and intra particle diffusion models. From the results, it was seen that Freundlich isotherm was best fit in the case of adsorption studies which followed pseudo second order kinetics. The obtained results showed that the chitosan-g-maleic anhydride-g-methacrylic acid copolymer was very efficient in removing the heavy metals copper and lead from aqueous solution.

Adsorptive Removal of Copper by Using Surfactant Modified Laterite Soil

Removal of copper ion (Cu2+) by using surfactant modified laterite (SML) was investigated in the present study. Characterizations of laterite were examined by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), inductively coupled plasma mass spectrometry (ICP-MS), and total carbon analysis. The optimum conditions for removal of Cu2+ by adsorption using SML were systematically studied and found as pH 6, contact time 90 min, adsorbent dosage 5 mg/mL, and ionic strength 10 mM NaCl. The equilibrium concentration of copper ions was measured by flame atomic absorption spectrometry (F-AAS). Surface modification of laterite by anionic surfactant sodium dodecyl sulfate (SDS) induced a significant increase of the removal efficiency of Cu2+. The surface modifications of laterite by preadsorption of SDS and sequential adsorption of Cu2+ were also evaluated by XRD and FT-IR. The adsorption of Cu2+ onto SML increases with increasing NaCl concentration from 1 to 10 mM, but at high salt concentration this trend is reversed because desorption of SDS from laterite surface was enhanced by increasing salt concentration. Experimental results of Cu2+/SML adsorption isotherms at different ionic strengths can be represented well by a two-step adsorption model. Based on adsorption isotherms, surface charge effects, and surface modification, we suggest that the adsorption mechanism of Cu2+ onto SML was induced by electrostatic attraction between Cu2+ and the negatively charged SML surface and nonelectrostatic interactions between Cu2+ and organic substances in the laterite.

Adsorption of copper on chitin-based materials: Kinetic and thermodynamic studies

Copper (Cu (II)) is one of the most toxic heavy metals usually found in the environment. Thus its removal from aqueous waste streams is an important issue in nowadays. The present work focuses on the comparison of the copper adsorption on chitin-based adsorbents, i.e. chitin (CH), chitosan (CS) and chitosan- ethylenediaminetetra-acetic acid (CS-EDTA). Chitin derivatives are carbohydrate materials well known to remove heavy metal ions from aqueous solutions. The effects of contact time, initial concentration, the temperature, pH, and mass of the adsorbent in the adsorption process were studied. The adsorption isotherms were well simulated by Langmuir and Freundlich models. The maximum adsorption capacity of CH, CS and CS-EDTA at 25°C, pH 7.0 was found to be 58, 67 and 110mg g−1, respectively. Thermodynamic parameters of adsorption processes such as Gibb's free energy (ΔG0), standard enthalpy (ΔH°) and entropy (ΔS0) were also calculated. The results showed that the studied materials could be used as effective adsorbents for removal of copper from water.

Melamine-based microporous polymer for highly efficient removal of copper(II) from aqueous solution

In this study, we investigated the ability of a melamine-based microporous polymer network as an adsorbent for removal of copper(II) species from aqueous solutions. A designed Schiff based network (SNW) with high specific surface area was synthesized using melamine and terephthalaldehyde monomers at 180 °C for 3 days followed by a freeze-drying process. The porous structure of the material was confirmed by SEM analysis and CO2 adsorption/desorption studies at 77.3 K. The adsorption character of the SNW polymer for various metal salts, namely Pb(II), Fe(II), Hg(II), Zn(II), Ni(II) and Cd(II), was investigated and a specific sorption behaviour against Cu(II) salts was observed. The role of pH and contact time was examined and the highest adsorption capacity for Cu(II) was found as 92% with pH 3.5 at the end of 300 min. As evidenced by XRD and Fourier transform infrared spectral analysis, the sorption mechanism is attributed to the coordination system formed between amino groups in the porous structure and Cu(II) ions. Reusability of the system was also demonstrated by applying four cycles without any significant loss of activity. © 2016 Society of Chemical Industry

Removal of Copper from Aqueous Solution Using Chemically Treated Potato (Solanum tuberosum) Leaf Powder

The present investigation describes the use of an agricultural waste; leaves powder derived from a specially cultivated Solanum tuberosum (potato) plant, as an adsorbent for copper removal from aqueous solutions. Batch experiments were performed based on parameters, such as pH at point of zero charge, pH, dosage, contact time, initial metal concentration, and temperature to study their effects on the removal capacity of copper from aqueous solutions. The kinetic data fitted well to the pseudo‐second order model, with a calculated adsorption capacity (qe) value (23.70 mg g−1) close to the experimental (qe) value (24.60 mg g−1). The adsorption data conformed best to the Langmuir isotherm as revealed by a lower non‐linear Chi‐square (χ2) value of 0.25 and a higher correlation value of 0.991 when compared to the Freundlich isotherm with a higher χ2 value of 0.78 and a lower correlation value of 0.985. The maximum adsorption capacity for the leaves powder was 42.74 mg g−1. The thermodynamic parameters (ΔG°, ΔS°, and ΔH°) showed that adsorption was feasible, spontaneous and endothermic. Fourier transform infrared (FTIR) spectroscopy confirmed the involvement of OH, NH, and CH of carboxylic acids and amino acids on the removal of copper from aqueous solutions. The results obtained in the present study indicated that S. tuberosum leaves powder can be used effectively to remove copper ions from aqueous solutions.

Copper(II) removal from the aqueous solution using microporous benzidine-based adsorbent material

In this work, the ability of benzidine-based microporous polymer network as adsorbent for removal of copper(II) species from aqueous solutions was investigated. The designed benzidine-based adsorbent material (BBAM) with high specific surface area was synthesized using phloroglucinol and benzidine monomers with hydrochloric acid catalyst at 180°C for 3 days followed by freeze–drying process. The porosity character of the material was confirmed by SEM analysis and CO2 adsorption/desorption studies at 0°C. The adsorption efficiency of the BBAM for different metal ions, namely Hg(II), Fe(II), Pb(II), Ni(II), Zn(II) and Cd(II) was experimented, however, a specific sorption behavior against Cu(II) ions was observed. The function of pH and contact time was studied and the highest adsorption capacities for Cu(II) were found as 97% with pH of 4.5 at the end of 300min. As verified by FTIR and XRD spectral analysis, the sorption mechanism is attributed to the coordination system formed between amino groups in the porous structure and Cu(II) ions. Reusability of the system was also presented by applying six cycles without any significant loss of activity.

Adsorptive removal of copper (II) from aqueous solutions on phosphates: equilibrium, kinetics, and thermodynamics

Limit of World Health Organization standard for safe amount Cu(II) in drinking water is 5 mg/L. The large usage of this material is reported to be the cause of various environmental and health hazard. Adsorption process that stands for the most common techniques due to its low cost and relative high efficiency, could perform its removal from wastewater. However, the most common adsorbents remain expensive compared with other potential natural and available adsorbents. In this work, natural and synthetic phosphates are tested for their efficacy to remove Cu(II) from contaminated water solution. Results were compared with those found with activated carbon used as reference. Effect of pH, adsorbent doses, temperature, and initial concentrations on the uptake of Cu ions by the adsorbent were examined based on statistical experimental design. Physical treatment was made to increase adsorption capacity of the tested adsorbents. The thermodynamic parameters such as free energy (ΔG°), enthalpy (ΔH°), and entropy changes (ΔS°) for the adsorption of Cu(II) were computed to predict the nature of adsorption process. Adsorption isotherms were determined and correlated with common isotherm equations such as Langmuir and Freundlich models. Adsorption data related to the two types of phosphate fit well pseudo-order model. Data confirm also net increase in adsorption with pH, adsorbent doses, while it decreases with an increase in initial concentration of copper. Variation of standard enthalpy (∆H°) and entropy (ΔS) were beyond zero. This indicates clear tendency of the adsorption process to randomness in the solid/solution interface and reflects exothermic nature of the process, while the negative value of standard free energy variation indicates spontaneous process. Langmuir model fitted much better than the Freundlich model. These materials were found to be promising as potential adsorbents for the removal of Cu(II) from aqueous solution.

Adsorptive removal of copper (II) ions from aqueous solution by silane cross-linked chitosan/PVA/TEOS beads: kinetics and isotherms

In this study, beads of chitosan (CS) containing polyvinyl alcohol (PVA) were prepared and cross-linked with tetraethoxysilane (TEOS). The cross-linking of CS/PVA beads with TEOS preserved the active adsorption sites of CS and also enhanced its chemical and mechanical stability. The chemical solubility test and swelling behavior of the beads were studied, especially, in acidic media. Adsorbents were characterized by infrared spectroscopy and scanning electron microscopy. The removal of Cu2+ ions from aqueous solution on the prepared beads was investigated in a batch adsorption system as a function of pH, amount of adsorbent, initial concentration of metal ions, and contact time. The adsorption data were analyzed on the basis of Lagergren pseudo-first-order, pseudo-second-order and interparticle diffusion models. Experimental data were fitted with Langmuir and Freundlich isotherm models. The maximum adsorption capacity of cross-linked CS/PVA/TEOS beads for copper ions was of 224.6 mg/g according to Langmuir isotherm for Cu2+ ions. The calculated thermodynamic parameters (∆G°, ∆H° and ∆S°) indicated a spontaneous and endothermic adsorption reaction.

Adsorptive removal of copper(II) from aqueous solution onto the waste sweet lime peels (SLP): equilibrium, kinetics and thermodynamics studies

Heavy metal pollution has become one of the most serious environmental problems today. Keeping in view of the economic and pollution considerations; there is indeed need to develop process and practice for the waste management, for the disposal of industrial waste containing Cu(II) in a scientific manner. In the present study, sweet lime peels (SLP), an agricultural waste was utilized as an adsorbent for Cu(II) removal from aqueous solution. The biosorption mechanism and characteristics of SLP was studied by Fourier transform infrared. Kinetic studies based on pseudo-first-order and pseudo-second-order rate expressions have also been carried out. The pseudo-second-order kinetics was found to provide the best correlation with the experimental data. The effect of two parameters, namely, temperature (20, 30, 40, 50 and 60°C) and pH (2, 3, 4, 5, 6), were studied. The particle size effect in relation to biosorption capacity is also discussed. The experimental data were analysed using Langmuir, Freundlich, Redlich–Peterson, Temkin and Dubinin–Radushkevich isotherms. The Langmuir model was found to exhibit the best fit to experimental data. The maximum adsorption capacity was found to be 37.45 mg/g at 293 K. Thermodynamic parameters such as free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) were also determined. Thermodynamic study showed that the biosorption was exothermic, spontaneous and favourable.

Adsorptive removal of copper(II) from aqueous solutions on activated carbon prepared from Tunisian date stones: Equilibrium, kinetics and thermodynamics

In this study, activated carbon produced from Tunisian date stones, a low-cost agricultural by-product, by chemical activation using H3PO4 as an activator was used as adsorbent for the removal of copper(II) ions from aqueous solutions. To optimize the preparation method, the effect of the main process parameters (such as acid concentration, impregnation ratio, and temperature of pyrolysis step) on the performances of the obtained activated carbons was studied. The optimal activated carbon was fully characterized considering its adsorption properties as well as its chemical structure and morphology.Optimum adsorption conditions were determined as a function of pH, initial copper concentration, contact time and temperature of solution for copper(II) removal. The results showed that the adsorption of copper(II) onto activated carbon produced by the optimum conditions was maximal at about pH 5.0. The rates of adsorption were found to conform to the pseudo-second-order kinetic model. The application of the intra-particle diffusion model revealed that the adsorption mechanism of copper(II) is rather a complex process and the intra-particle diffusion is involved in the overall rate of the adsorption process but it is not the only rate-controlling step. The isotherm equilibrium data were well fitted by the Langmuir and Dubinin–Radushkevich isotherm models with a monolayer maximum adsorption capacity of 31.25mg/g. According to the experimental results, the adsorbent derived from this material is expected to be an economical product for metal ion remediation from water and wastewater.

Template Preparation of Poly(Vinylpyrrolidone-Itaconic Acid) and Their Application in Removal of Copper Ions

Poly(vinyl pyrrolidone-itaconic acid) P(VP-IA) was prepared by the template polymerization of itaconic acid (IA) in the presence of PVP as a template polymer using gamma rays. Fourier transform infrared results showed that the interpolymer complexes were formed by hydrogen bonds between the carboxyl groups of PIA and the carbonyl groups of PVP. P(VP-IA) resin could be employed as a potential adsorbent for the removal of heavy metals such as Cu(II). The capacity of the prepared polymer containing different amounts of PVP, N,N′-methylene-bis-acrylamide (NMBA) and IA concentration was investigated. It is obvious that the adsorption capacity increased with increasing itaconic acid content. Although it decreased with increasing the concentration of PVP and NMBA. P(VP-IA) was found to be a potential adsorbent for removal of copper from aqueous medium. Detail adsorption study of Cu(II) on P(VP-IA) was investigated. Batch adsorption study was carried out as a function of contact time, adsorbent dose, and pH. Adsorption isotherms of Cu(II) on adsorbents were determined and correlated with common isotherm equations such as Langmuir, Freundlich and Tempkin adsorption isotherm models. The maximum adsorption capacities for Cu(II) on P(VP-IA) were found to be 131 mg g−1.

Mechanistic Insights into Copper Removal by Pyrolytic Tire Char through Equilibrium Studies

This study showed that copper(II) can be removed from aqueous solution by activated pyrolytic tire char in three mechanistically distinct ways. On the basis of equilibrium studies, the mechanisms involved in the adsorptive removal of copper(II), namely, precipitation, surface adsorption, and pore diffusion, were elucidated. Precipitation of copper(II) resulted from changes in the solution pH to neutral levels. This was attributed to amphoteric zinc oxide on the char surface, formed during production of the pyrolytic char. Surface adsorption was revealed by X-ray photoelectron spectroscopy data, which showed a significant increase in copper(II) on the char surface after shaking in the copper solution. This surface adsorption took place despite the relatively low surface area and porosity of the char. However, some cracks and fissures were found to exist in the char that can trap small species such as copper ions. These trapped copper species were partially recovered by microwave-assisted acid digestion of the char.

Adsorption of Copper Ions and Methylene Blue in a Single and Binary System on Wheat Straw

A natural wheat straw was used as adsorbent for removal of copper and methylene blue (MB) from aqueous solution. A batch system was applied to study the behavior of Cu2+ and MB adsorption in single and binary systems on wheat straw. In the single systems, there was no significant difference in the quantity of MB adsorbed onto wheat straw within a pH range of 4.0 to 10.0. But for Cu2+, the optimal pH is about 5. Kinetic studies indicate that Cu2+ and MB adsorption on the wheat straw follows the Elovich equation. The Cu2+ adsorption isotherm follows the Langmuir and Redlich−Peterson models, while MB adsorption follows the Redlich−Peterson isotherm. The adsorption capacities of Cu2+ and MB at 273 K and pH 5 are (7.05 and 60.66) mg·g−1, respectively. In the binary system, Cu2+ and MB exhibited competitive adsorption. The adsorption of Cu2+ or MB is considerably reduced with an increasing concentration of the other. The quantity of Cu2+ adsorbed is more strongly influenced by MB due to the higher affinity of wheat straw for the latter. As wheat straw is easily obtained and cheap, it will be promising for removal of metal ions and dyes.

Characterization and properties of iron oxide-coated zeolite as adsorbent for removal of copper(II) from solution in fixed bed column

Abstract A new composite adsorbent, iron oxide coated zeolite (IOCZ), was characterized and employed for the removal of Cu(II) from aqueous solution using fixed bed column. Scanning electron microscope (SEM), FTIR, X-ray diffraction spectrum (XRD) and BET analyses were used to study the surface properties of the coated layer. The effects of various experimental conditions, such as the flow rate, initial metal concentration and bed depth, were studied. The dynamics of the adsorption process were fitted by Adams–Bohart model and Thomas model. The Thomas model was found suitable for the description of breakthrough curve at all experimental conditions, while Adams–Bohart model was only for an initial part of dynamic behavior of the IOCZ column. The bed depth service time (BDST) model was applied to predict the service times with other flow rate and initial concentration. The theoretical breakthrough curve was compared with experimental breakthrough curve profile in the dynamic process. The saturated column was regenerated by 1 mol l−1 hydrogen chloride solution and IOCZ could be reused in Cu(II) removal.

Adsorptive removal of copper and nickel ions from water using chitosan coated PVC beads

A new biosorbent was developed by coating chitosan, a naturally and abundantly available biopolymer, on to polyvinyl chloride (PVC) beads. The biosorbent was characterized by FTIR spectra, porosity and surface area analyses. Equilibrium and column flow adsorption characteristics of copper(II) and nickel(II) ions on the biosorbent were studied. The effect of pH, agitation time, concentration of adsorbate and amount of adsorbent on the extent of adsorption was investigated. The experimental data were fitted to Langmuir and Freundlich adsorption isotherms. The data were analyzed on the basis of Lagergren pseudo first order, pseudo-second order and Weber–Morris intraparticle diffusion models. The maximum monolayer adsorption capacity of chitosan coated PVC sorbent as obtained from Langmuir adsorption isotherm was found to be 87.9 mg g −1 for Cu(II) and 120.5 mg g −1 for Ni(II) ions, respectively. In addition, breakthrough curves were obtained from column flow experiments. The experimental results demonstrated that chitosan coated PVC beads could be used for the removal of Cu(II) and Ni(II) ions from aqueous medium through adsorption.

Removal of copper from aqueous solution using newspaper pulp as an adsorbent

Newspaper pulp was found to be a potential adsorbent for removal of copper from aqueous medium. Detail adsorption study of Cu on newspaper pulp was investigated. Batch adsorption study was carried out as a function of contact time, adsorbent dose, temperature (303–323 K). The experimental data was analyzed using Freundlich, Langmuir, Dubinin–Radushkevich (D–R) and Redlich-Peterson (R–P) isotherm models. It was found that Freundlich, Langmuir and R–P models fitted well. pH variation study revealed that the adsorption increased with increase in pH of the solution. Maximum loading capacity was found to be 30 mg g −1 at 20 mg L −1 of initial Cu concentration. Adsorption data were analyzed using two kinetic models, Lagergren first order and pseudo second order. It was observed that pseudo second order represented the best correlation. Langmuir isotherm was used to obtain the thermodynamic parameters such as free energy (Δ G°), enthalpy (Δ H°) and entropy (Δ S°) of adsorption. The negative value of free energy and positive value of enthalpy change indicate that the adsorption of Cu on newspaper pulp is a spontaneous process and endothermic. The results of activation energy also confirmed that the adsorption of Cu on newspaper pulp is physical in nature. Present investigation emphasized that newspaper pulp may be utilized as a low cost adsorbent for copper removal.

Characterization and Properties of Manganese Oxide Coated Zeolite as Adsorbent for Removal of Copper(II) and Lead(II) Ions from Solution

A new adsorbent, manganese oxide coated zeolite (MOCZ), was characterized and employed for the removal of Cu(II) and Pb(II) from aqueous solution using batch equilibrium experiments. Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and BET analyses were used to observe the surface properties of the coated layer. Binding of Cu(II) and Pb(II) ions by MOCZ was clearly pH-dependent, and the loading capacities increased with increasing pH. Adsorption behavior of Cu(II) and Pb(II) ions can be approximately described with the Langmuir and Redlich−Peterson equation. The thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were also determined, and the adsorption process is more favored at higher temperatures.

Removal of copper from aqueous solutions by phosphate rock

A study was carried out to examine the removal of copper from an aqueous solution by phosphate rock (PR). The adsorption method was applied and optimum conditions for adsorption were evaluated by changing various parameters; effects of pH, adsorbent concentration, initial metal concentration and contact time were investigated. The study shows that copper removal from an aqueous solution increases with increasing pH and adsorbent concentration (up to 5 g/l) and decreases with increasing initial copper concentration, and the equilibrium (contact) time was 40 min. The adsorption capacity of PR was determined as 0.17 mmol/g by fitting the experimental results to Langmuir and Freundlich isotherms. XRD analysis and infrared spectra analysis were used to characterize the mineralogical compositions of original and treated samples and the structural change on the sorbent after its treatment with 100 mg/l of copper (II), respectively. PR was found suitable as an adsorbent for removal of copper from aqueous solutions.

Adsorptive Removal of Copper(II) on N-Methylene Phosphonic Chitosan Derivative

A crosslinked N-methylene phosphonic chitosan (=NMPC) was newly synthesized by reacting chitosan with phosphorous acid in order to remove traces of copper(II) from a crude palladium(II) solution. First of all, the adsorption selectivity of NMPC for metal ions was examined from a 1 mol/dm3 (=M) aqueous ammonium nitrate solution. The adsorption of metal ions on NMPC was dependent on an equilibrium pH, and their adsorption shifted to a lower pH region compared with crosslinked original chitosan (=CLC). NMPC began to adsorb all the metal ions except for palladium(II) at around pH 1–3 and then their adsorption increased with an increase in pH. On the contrary, palladium(II) was adsorbed in lower pH around 0–1, then its adsorption rapidly decreased with increasing pH. These results indicate that base metals can be selectively separated and removed from the crude palladium(II) solution using NMPC only by adjusting the pH. Especially, the adsorption equilibrium of copper(II) was quantitatively examined since the separation of copper(II) from a crude palladium(II) solution is commercially very important. The adsorption of copper(II) showed the maximum value at around pH 5 and then it rapidly decreased in the higher pH region. The adsorption of copper(II) was little dependent on the ammonium nitrate concentration at pH < 4, however, beyond which it decreased with the increasing concentration of ammonium nitrate. The adsorption equilibrium of copper(II) was quantitatively discussed by taking account of the formation of ammine complexes of copper(II) with ammonia in the higher pH region. The adsorption capacity of NMPC for copper(II) was 3.81 mol/kg, which is twofold greater than that of CLC.

Reusing sewage sludge ash as adsorbent for copper removal from wastewater

The sewage sludge ash (SSA) can potentially be used for removal of heavy metals from wastewater due to its similar chemical composition to that of fly ash and blast-furnace slag. This study investigated the adsorptive characteristics of SSA including specific surface area, cation-exchange capacity (CEC), and pH of zero point of charge (pH ZPC). In addition, the adsorption isotherms of SSA with synthetic wastewater containing copper ions were tested. Experimental results indicated that the CEC and pH ZPC of SSA were 24.1–25.7 meq/100 g and 3.1–3.4, respectively, which exhibited the capability of removing heavy metals from wastewater. The adsorption test of applying SSA into synthetic wastewater revealed that the adsorption isotherm of SSA for copper ions generally followed the Langmuir model. The estimated maximum capacity of copper adsorbed by SSA was 3.2–4.1 mg/g and close to that of fly ash. The primary mechanisms of copper removal by SSA included electrostatic attraction, surface complex formation, and cation exchange. The precipitation of copper hydroxide occurred only when the dosage of SSA and the equilibrium pH of wastewater were at a high level (30–40 g/l and greater than 6.2, respectively). In general, similar to fly ash and blast-furnace slag, the SSA can be reused as an adsorbent for copper removal from wastewater and the removal efficiency was greater than 98%.