Reciprocal effect of Pb(II) and surfactant onto their sorption in weak acid polyacrylic cation exchanger

The decrease in the equilibrium sorption of Pb(II) and nonionic surfactants (oxyethylated alcohols OS-20 and alkylmonoethers ALM-10) in H-form of Purolite C 106 cation exchanger was observed due to their presence in the same solution. The sorption of Pb(II) both in the form of free cations and in the form of Pb(II) bonded with surfactant takes place. The sorption of Pb(II) bonded with OS-20 is higher compared with that of Pb(II) bonded with ALM-10. In the presence of ALM-10 the sorption of Pb(II) free cations prevails. Increasing the acidity from pH 5 to pH 3, increases the rate of the sorption of surfactant. Due to the presence of surfactant the rate of Pb(II) sorption also increases, while without surfactant it decreases with an increase in acidity. © 1998 SCI     

Kinetics of cadmium(II) sorption by an iminodiacetic ion exchanger in the presence of a nonionic surfactant

The kinetics of cadmium(II) sorption from separate solutions and from the mixtures with nonionic surfactant Lutensol AO-10 (oxyethylated alkohols) in hydrogen form of chelating iminodiacetic ion exchanger Purolite S-930 has been investigated: kinetic curves and breakthrough curves have been obtained, determining the concentration of nonionic surfactant spectrophotometrically, and that of cadmium(II) complexometrically. The kinetic coefficients (B_t), the coefficients of the intraparticle diffusion (D, m²s⁻¹), the effective kinetic coefficients of the external mass transfer (β, s⁻¹), the overall rate constants (k₀, s⁻¹) and the distribution coefficients (K_d) have been calculated. Cadmium(ll) sorption from the separate solutions and from the mixtures with AO-10 is controlled by the intraparticle diffusion at pH 5 and pH 7.6. Reducing the initial solution acidity from pH 5 to pH 7.6, the coefficients of intraparticle diffusion (D) for cadmium(II) increase, although they decrease as the cation exchanger saturation increases. The equilibrium sorption of cadmium(II) is slightly higher at pH 7.6 than at pH 5 both without and with the surfactant. The performance of Purolite S-930 packed column with respect to cadmium(II) is better in the absence than in the presence of the surfactant: the action of AO-10 interferes with the removal of cadmium(II). The sorption of AO-10 is negligible both in the absence and in the presence of cadmium(II). Regeneration of Purolite S-930 using 0.7 M HCl for both the removal of cadmium(II) and the conversion into hydrogen form enables the 100% recovery of the sorptive capacity. The rate of the cadmium(ti) intraparticle diffusion, its negligible concentration at the breakthrough, sufficiently high equilibrium sorption and the ability to restore the sorptive capacity refer to the possibility of the hydrogen form of Purolite S-930 practical use, including the purification of plating rinse water for its recycling, preventing the environmental contamination with cadmium(II).     

Sorption of Zn(II) and Pb(II) ions in the presence of the biodegradable complexing agent of a new generation

The macroporous chelating ion exchangers containing different functional groups i.e. Purolite S-920, Purolite S-930 and Lewatit TP-208 have been used in the sorption process of Zn(II) and Pb(II) ions. The effect of the presence of biodegradable, environmentally friendly aminopolycarboxylate chelating agent, trisodium salt of methylglycinediacetic acid (MGDA) on its sorption capacity was also examined. The investigations were carried out by the static method. Besides the effect of initial concentration of Zn(II) and Pb(II) and the complexing agent the research concerns the influence of solution pH, phase contact time on effectiveness of sorption. The equilibrium and kinetics of Zn(II)–MGDA and Pb(II)–MGDA complexes sorption were obtained and fitted using the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D–R) models as well as the pseudo first and pseudo second order kinetic models. The intraparticle diffusion model was also used. The results showed that the sorption processes of Zn(II) and Pb(II) complexes with MGDA on Purolite S-920, Purolite S-930 and Lewatit TP-208 followed well the pseudo second order kinetics.     

KINETICS OF CADMIUM ION SORPTION ON ION EXCHANGE AND CHELATING RESINS

ABSTRACT

Cadmium sorption from aqueous solutions on sulfonic (C-150) and iminodiacetic (S-930) Purolite macroporous resins was investigated. The influence of operating variables such as initial pH, Cd(H) concentration, time and temperature on the equilibrium parameters was measured. The ion preference and sorption ability of resins, i.e. binding constant (b) and saturation capacity {x_m), derived from sorption isotherm, depend on the functional group structure. The Cd(II) uptake is only particle diffusion controlled. The kinetic parameters, i.e. t_1/2 values for 50 % attainment of equilibrium sorption, rate constant (K¯ ) and diffusion coefficient (D¯) are higher on the sulfonic resin. The “moving boundary” particle diffusion model fits the entire ion sorption process on chelating resin, but only the initial sorption on the sulfonic resin, confirming the difference in chemistry between chelation and ion exchange.     

Polyacrylate anion exchangers in sorption of heavy metal ions with the biodegradable complexing agent

The removal of Co(II) and Ni(II) from aqueous solutions in the presence of complexing agent on the polyacrylate anion exchangers with different basicity of functional groups Amberlite IRA 458, Amberlite IRA 958 and Amberlite IRA 67 was described. The complexing agent Baypure CX 100 is a new generation of chelators, undergoing biodegradation. It constitutes an alternative for the reagents of EDTA or NTA type. The studies were carried out by the static (batch) and the dynamic (column) methods. The influence of several parameters such as ratio of M(II)–L, pH, temperature were studied with respect to sorption equilibrium. Sorption isotherms were obtained and fitted using the Langmuir and Freundlich models. Kinetic curves were fitted using the pseudo first-order, the pseudo second-order as well as the intraparticle diffusion model equations to evaluate most effective one. Physicochemical properties of anion exchangers such as their structure, basicity of functional groups were also taken into account. Additionally, the obtained results were compared with those for the weakly acidic cation exchanger Purolite C-104.     

Comparison of ion-exchange resins for efficient cobalt(II) removal from acidic streams

The ion-exchange method was applied for cobalt(II) removal from acidic streams using Lewatit MonoPlus TP 220, Purolite A 830, Lewatit SR 7, Purolite S 984, Purolite A 400 TL, Lewatit AF 5, Dowex PSR 2, and Dowex PSR 3. The effects of phase contact time, acid concentration, initial Co(II) concentration, and temperature were evaluated. The cobalt(II) desorption, ion exchanger reuse, and attenuated total reflection with the Fourier transform infrared spectroscopy, column studies were also performed. Lewatit MonoPlus TP 220 exhibits the highest sorption capacities and sorption follows the pseudo-second-order kinetics. The Freundlich model fitted the experimental data adequately. Desorption of cobalt(II) loaded is not quantitative. Sorption capacity reduction after three cycles of sorption–desorption (static method) was not observed.     

Sorption of Cd(II), Co(II), and Zn(II) Complexes with MGDA on Anion Exchange Resins: A Study of the Influence of Various Parameters

The strongly basic polystyrene gel resins Amberjet 4200, Amberjet 4600, and the macroporous strongly basic polystyrene Purolite A 520E were investigated for their sorption properties towards Cd(II), Co(II), and Zn(II) complexes with MGDA. The object of the study was the sorption behavior of three metal ions on the above-mentioned anion exchangers, depending on the metal ions’ concentration, pH, contact time, and temperature. MGDA is an alternative, environmentally friendly complexing agent. The sorption data were fitted to the Langmuir and Freundlich models. Three different kinetic behaviors: pseudo first order, pseudo second order, and intraparticle diffusion were tested. The variations of thermodynamic functions were also calculated.     

Ligand sorption kinetics of aromatic amines on new ligand-exchanger sporopollenin in cobalt ion form

An approach to study of intraparticle ion-exchange kinetics of aromatic amines such as p-chloroaniline, p-toluidine, and p-nitroaniline as ligands on Co²⁺ loaded-ligand exchanger of sporopollenin (carboxylated epichlorohydrine [CEP]–sporopollenin) is presented and the ligand-exchange reaction in the resin matrix is shown to be rate-determining. Kinetic studies of aromatic amines as ligands on the CEP–sporopollenin have been performed using continuous column runs. The observed rate seems to be related to the rate of ligand sorption with the mobile phase (ion) and pH in the aqueous phase. The rate of attainment of equilibrium sorption and breakthrough curves of aromatic amines is seen to be nearly similar. With the sorption mechanism deduced to be dominantly particle diffusion-controlled, diffusion coefficients determined were found to range from 1.10^?8 to 1.0 10^?9 cm²s^?1. Coupled with the fact that different concentrations of solution were employed, these results may be interpreted as indicating that particle diffusion is the rate-determining step; on the contrary, film diffusion was not a rate-controlling step in the ligand-sorption process under the conditions employed. © 1995 John Wiley & Sons, Inc.     

Removal of Copper (II) Ions from Aqueous Solutions using Na‐mordenite

Abstract

The potential to remove copper (II) ions from aqueous solutions using Na‐mordenite, a common zeolite mineral, was thoroughly investigated. The effects of relevant parameters solution pH, adsorbent dose, ionic strength, and temperature on copper (II) adsorption capacity were examined. The sorption data followed the Langmuir, Freundlich, and Dubinin‐Radushkevich (D‐R) isotherms. The maximum sorption capacity was found to be 10.69 mg/g at pH 6, initial concentration of 40 mg/dm³, and temperature of 40°C. Different thermodynamic parameters viz., changes in standard free energy (ΔG⁰), enthalpy (ΔH⁰), and entropy (ΔS⁰) have also been evaluated and the results show that the sorption process was spontaneous and endothermic in nature. The dynamics of the sorption process were studied and the values of rate constant of adsorption, rate constant of intraparticle diffusion were calculated. The activation energy (E_a) was found to be 11.25 kJ/mol in the present study, indicating a chemical sorption process involving weak interactions between sorbent and sorbate. The interaction between copper (II) ions and Na‐mordenite is mainly attributable to ion exchange. The sorption capacity increased with the increase of solution pH and the decrease of ionic strength and adsorbent dose. The Na‐mordenite can be used to separate copper (II) ions from aqueous solutions.     

Batch adsorptive removal of copper ions in aqueous solutions by ion exchange resins: 1200H and IRN97H

The removal of copper from aqueous solution by ion exchange resins, such as 1200H and IRN97H, is described. Effect of initial metal ion concentration, agitation time and pH on adsorption capacities of ion exchange resins was investigated in a batch mode. The adsorption process, which is pH dependent, shows maximum removal of copper in the pH range 2–7 for an initial copper concentration of 10 mg/L. The experimental data have been analyzed by using the Freundlich, Langmuir, Redlich-Peterson, Temkin and Dubinin-Radushkevich isotherm models. The batch sorption kinetics have been tested for a first-order, pseudo-first order and pseudo-second order kinetic reaction models. The rate constants of adsorption for all these kinetic models have been calculated. Results showed that the intraparticle diffusion and initial sorption into resins of Cu(II) in the ion exchange resins was the main rate limiting step. The uptake of copper by the ion exchange resins was reversible and thus has good potential for the removal/recovery of copper from aqueous solutions. We conclude that such ion exchange resins can be used for the efficient removal of copper from water and wastewater. This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University.     

Evaluation of Nickel Sulphide Prepared by Different Routes for Removal of 106Ru from Alkaline Radioactive Liquid Waste

An attempt has been made to synthesize nickel sulphide (NiS) compound by different routes. The NiS material thus obtained was coated on polymethyl metha acrylate (PMMA) beads to form a composite material, which was subjected to its performance evaluation for uptake of ¹⁰⁶Ru from low level radioactive liquid waste (LLW) stream. Distribution Coefficient (K_d) of ¹⁰⁶Ru from LLW using NiS–PMMA composite beads was found to be in the range of 9000–12000 (ml/g). The effect of various parameters viz. pH, ionic strength, temperature, time equilibration, etc. towards the uptake of ¹⁰⁶Ru was investigated. The sorption mechanism was also studied. The ΔG, ΔH, and ΔS value for sorption were evaluated. The sorption was observed to be spontaneous and endothermic in nature. From the practical utilization point of view, the rate of uptake of ¹⁰⁶Ru by the composite material was studied. The data of sorption was investigated with Lagergren first-order, pseudo-first-order, and second-order plots. Its intraparticle diffusion mechanism was studied with the Weber Morris model. The kinetics was found to follow a pseudo-first-order pattern with intraparticle diffusion. However, intraparticle diffusion is not the rate controlling step.     

Application of ion exchangers for the purification of galvanic wastewater from heavy metals

The aim of the present study was to investigate the sorption and physicochemical properties of the chelating ion exchangers with bis(2-pyridylmethyl)amine and aminophosphonic functional groups before and after the sorption of galvanic wastewaters. The study was carried out on the Dowex M4195, Lewatit^® MonoPlus TP 220, Purolite S 940 and Purolite S 950 ion exchangers. For the practical use of the studied ion exchangers in the process of wastewater purification, the sorption capacity of the above-mentioned ions was determined depending on the phase contact time and sorption process in the whole volume of the beads.     

STUDY OF HG(II) REMOVAL FROM AQUEOUS SOLUTION USING LIGNOCELLULOSIC COCONUT FIBER BIOSORBENTS: EQUILIBRIUM AND KINETIC EVALUATION

Lignocellulosic coconut wastes such as pith and fiber, which are abundantly available and cheap, have the potential of being used as low-cost biosorbents for heavy metal ion removal. In this study, pristine (CF-Pristine) and NaOH-treated (CF-NaOH) coconut fibers were used as a biosorbent for Hg(II) removal from an aqueous solution. The coconut fiber biosorbent (CFB) was characterized by scanning electron microscopy (SEM) and Fourier transform-infrared (FTIR) spectroscopy. The Hg(II) sorption capacities obtained for CF-Pristine and CF-NaOH were 144.4 and 135.0 mg/g, respectively. Both the equilibrium and kinetic data of Hg(II) sorption onto CFB followed the Langmuir isotherm model and a pseudo-second-order kinetic model, respectively. A further analysis of the kinetic data suggested that the Hg(II) sorption process was governed by both intraparticle and external mass transfer processes, in which film diffusion was the rate-limiting step. These results demonstrated that both pristine- and alkali-treated coconut wastes could be potential low-cost biosorbent alternatives for the removal of Hg(II) from aqueous solutions, such as water containing Hg(II) produced in the oil and gas industry.     

SEPARATION OF CESIUM FROM NUCLEAR WASTE SOLUTIONS WITH HEXACYANOFERRATE(II)S AND AMMONIUM PHOSPHOMOLYBDATE

ABSTRACT The separation of 134, 137 Cs from nuclear power plant low-level waste solutions by ion exchange with potassium cobalt hexacyano-ferrate(II), potassium copper cobalt hexacyanoferrate(II) and ammonium phosphomolybdate was studied. The pH of the waste solutions was 6-13 and the concentrations of sodium and potassium ions were 8 - 2700 and 0.5 - 240 mmol/1, respectively. The distribution coefficient of cesium was determined as a function of pH, sodium and potassium ion concentrations and of the ratio of solution volume to exchanger weight (batch factor). The ion exchange rate of cesium was determined for three exchanger grain sizes and at temperatures of 20, 40 and 60° C. A potassium copper cobalt hexacyanoferrate(II) column was tested for cesium separation from a highly alkaline (pH 13) waste solution containing high concentrations of sodium (2.7 M) and potassium (0.24 M) ions; the 1% breakthrough capacity was very high, 12800 bed volumes.     

Tetraalkylphosphonium Ionic Liquid Encapsulation in Alginate Beads for Cd(II) Sorption from HCl Solutions

Cyphos IL 105 (tetraalkylphosphonium dicyanamide) was immobilized in alginate capsules (IL vesicle entrapped in a biopolymer layer, as shown by SEM-EDX analysis). This material was tested for efficient Cd(II) sorption from HCl solutions. The concentration of HCl and chloride ions hardly influenced metal sorption that proceeds through ion exchange between Cd(II) (under the form of CdCl₄^2?) and 2 dicyanamide groups. The sorption capacity (at saturation of the resin) proportionally increased with IL content (respecting the 1:2 stoichiometry between Cd(II) and the phosphonium cation). The uptake kinetics are well described by the Crank’s equation (resistance to intraparticle diffusion) and by the pseudo-second order rate equation (chemical reaction rate).     

Polyacrylate anion exchangers in sorption of heavy metal ions with non-biodegradable complexing agents

The polyacrylate anion exchangers are widely used in purification of heavy metal ions from wastewaters and different accompanying complexing agents. Such effluents containing the chelators (EDTA, NTA, HEDTA, DTPA, and IDA) are discharged from relevant industries such as printed circuits boards, plating on plastics, metal finishing and others. The sorption was studied as a function of phase contact time and pH by the batch technique. It was found that the removal of heavy metal ions in the presence of EDTA, NTA and IDA strictly depends on the phase contact time and pH values. Various kinetic models such as the pseudo first-order and the pseudo second-order as well as the intraparticle one were also tested to estimate the sorption rate. The equilibrium capacities of the studied anion exchangers for Cu(II), Zn(II), Co(II), Ni(II), Pb(II) and Cd(II) in the presence of EDTA were the highest for Pb(II) and Cd(II). The order of sorption for Amberlite IRA 458, Amberlite IRA 958 as well as Amberlite IRA 67 can be as follows: Pb(II) > Cd(II) > Zn(II) > Cu(II) > Ni(II) > Co(II). The stability of forming complexes was also compared. The estimation of the capacities of anion exchangers under investigation by the continuous column studies was also carried out.     

New poly(N-δ-acryloyl ornithine) gels cross-linked with N,N′-methylenebisacrylamide. Sorption properties

To make a polymer from ornithine the acryloyl group was added to δ-amino group of the amino acid and N-δ-acryloyl ornithine was polymerized. The presence of α-amino acid groups attached to the polymeric network of the gels enables the complexation of some di- and trivalent metal cations. Copper ions, which can form two complexes of different stoichiometry (1:1 and 1:2) with amino acids, were used to investigate the influence of the complexation process on the swelling behavior and sorption properties of the obtained gels. The swelling ratio decreased as copper ion concentration increased. The poly(N-δ-acryloyl ornithine) gel was most sensitive to the copper ions in the concentration range of 1-100 mg/mL. The obtained UV-Vis spectra indicated that the copper ions mainly formed complexes of stoichiomery 1:2 with the α-amino acid group. Copper ion uptake was found to exceed 94% in a wide pH range (4-10). The maximum sorption capacity calculated by applying the Langmuir equation was 18.0 mg/g. Kinetic data showed that the sorption process reached equilibrium within 30 min and indicated the importance of the intraparticle diffusion step.     

Sol–gel synthesis,physicochemical characterization,and analytical applications of copper selective composite cation exchanger: Polyvinyl alcohol Ce(IV) phosphate

An organic–inorganic composite cation exchanger polyvinyl alcohol Ce(IV) phosphate was prepared by the sol–gel method. The composite cation exchanger was characterized by some physicochemical properties like FTIR, TGA/DTA/DTG, XRD, SEM, TEM, EDX, and ion exchange properties to validate the structure and the ion exchange behavior. Ion exchange parameters indicated that the composite material is suitable for column operation. The ion exchange capacity of the composite ion exchanger is higher than that of the inorganic counterpart which showed that the incorporation of organic polymer polyvinyl alcohol (PVA) is responsible for prevention of the leaching of inorganic ion exchanger thereby proving mechanical stability and enhanced ion exchange properties. The distribution studies showed the selectivity toward Cu(II) ions, a heavy toxic metal ion. It was also observed that the selectivity depended upon the nature and composition of contacting solvents. The binary separation of a mixture of heavy metal ions Cu(II)–Zn(II), Cu(II)–Cd(II), and Cu(II)–Ni(II) also achieved thus composite cation exchanger proved excellent material could be effectively utilized in the treatment of discharge from copper plating, copper alloy, copper batteries, and smelting industries, whereas outstanding thermal stability of this composite ion exchanger could be utilized for the treatment of wastewater having Cu(II) ions with high temperature such as power generation and desalination plants. This composite ion exchanger with outstanding properties have potential to deal with aquatic toxicology caused by Cu(II) ions in future. POLYM. COMPOS., 38:332–340, 2017. © 2015 Society of Plastics Engineers     

Diffusion kinetic study of cadmium(II) biosorption by Aeromonas caviae

The removal of cadmium from aqueous solution by sorption on Aeromonas caviae particles was investigated in a well‐stirred batch reactor. Equilibrium and kinetic experiments were performed at various initial bulk concentrations, biomass loads and temperatures. Biosorption equilibrium was established in about 1 h and biosorption was well described by the Langmuir and Freundlich biosorption isotherms. The maximum biosorption capacity was found as 155.32 mg Cd(II) g^?1 at 20 °C. The obtained sorption capacity is appreciably high for most experimental conditions; so A caviae may be considered as a suitable biosorbent for the removal of cadmium. Moreover, the sorption rate of cadmium onto A caviae particles was particularly sensitive to initial bulk concentration and solid load. A detailed analysis was conducted, examining several diffusion (external and intraparticle) kinetic models in order to identify a suitable rate expression. The results are discussed and indicate that biosorption of cadmium is a complex process that is described more correctly by more than one model. Copyright © 2004 Society of Chemical Industry     

Biosorption studies of Cu(II) onto Mansonia sawdust: Process design to minimize biosorbent dose and contact time

The aim of this paper is to examine the various operating processes and determine the overall biosorption rate and how each of the processes influences biosorption. The results revealed that external mass transfer, film diffusion and ion exchange were predominant at the initial 5 min of biosorption and their rate constants were measured. The pseudo-second order model rate constants were determined and the relationship between these constants and the biosorption performance such as the approaching equilibrium factor, R_w, the rate factor k₂q_e, the biosorption half-life (t^0.5) and the operating time (t_x) were determined. The pore and film diffusion coefficients decreased with increasing copper(II) concentration. The values of initial biosorption factor, R_i, for the biosorption process showed that for all initial copper(II) concentrations, initial biosorption was faster than intraparticle diffusion. The activation energies, enthalpies, entropies and free energies for each of the operating processes were determined and the results showed that film diffusion had the highest activation energy and may be the overall rate limiting step. Mathematical models for the optimization of multistage process for minimum biosorbent mass and contact time were also developed.