Removal of Cu(II), Zn(II) and Co(II) ions from aqueous solutions by adsorption onto natural bentonite (original) (raw)
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Removal of Pb(II), Cd(II), Cu(II), and Zn(II) from Aqueous Solutions by Adsorption on Bentonite
Journal of Colloid and Interface Science, 1997
tion. It is an inexpensive clay mineral readily available in Removal of Pb(II), Cd(II), Zn(II), and Cu(II) from aqueous Turkey. It has been extensively used in drilling processes, solutions using the adsorption process on bentonite has been invesbut few scientists have used clay minerals in water and waste tigated. In order to find out the effect of temperature on adsorpwater pollution control (7-9). In the present study, removal tion, the experiments were conducted at 20, 35, and 50ЊC. For all of Pb(II), Cd(II), Cu(II), and Zn(II) from aqueous soluthe metals, maximum adsorption was observed at 20ЊC. The rate tion by adsorption was investigated. Adsorption isotherms of attaining equilibrium of adsorption of metal ions follows the and thermodynamic parameters of the adsorption are also order Zn(II) ú Cu(II) ú Cd(II) ú Pb(II). Equilibrium modeling presented.
THE REMOVAL OF HEAVY METAL IONS (COPPER, ZINC, NICKEL AND COBALT) BY NATURAL BENTONITE
The removal of Copper (Cu 2+ ), Zinc (Zn 2+ ), Nickel (Ni 2+ ) and Cobalt (Co 2+ ) from aqueous solutions by adsorption onto natural bentonite was investigated. Experiments were carried out as a function of shaking time, temperature of solution and thermal treatment of bentonite. The kinetic processes of metal ions adsorption on bentonite were described by applying pseudo-first order and pseudo-second order rate equations. The pseudo-second order reaction rate model was found to describe best the kinetic data. The thermodynamic parameters (ΔH, ΔS and ΔG) for Copper (Cu 2+ ), Zinc (Zn 2+ ), Nickel (Ni 2+ ) and Cobalt (Co 2+ ) adsorption onto bentonite were also determined from the temperature dependence. The adsorption was endothermic reactions for Copper (Cu 2+ ) and Zinc (Zn 2+ ), and exothermic for Nickel (Ni 2+ ) and Cobalt (Co 2+ ). The results suggested that natural bentonite is suitable as an adsorbent material for adsorption of metal ions from aqueous solutions. Keywords: natural Bentonite, Copper (Cu 2+ ), Zinc (Zn 2+ ), Nickel (Ni 2+ ) and Cobalt (Co 2+ ), adsorption, thermodynamic parameters.
Equilibrium, kinetic and thermodynamic aspects of the adsorption of copper ions from an aqueous solution using linear alkylbenzene sulfonate (LABORA-TORIES) modified bentonite (organo-bentonite) are reported. Modification of bentonite was performed via microwave heating with a concentration of LABORA-TORIES surfactant equivalent to 1.5 times that of the cation exchange capacity (CEC) of the raw bentonite. Experimental parameters affecting the adsorption process such as pH, contact time and temperature were studied. Several adsorption equations (e.g., Langmuir, Freundlich, Sips and Toth) with temperature dependency were used to correlate the equilibrium data. These models were evaluated based on the theoretical justifications of each isotherm parameter. The Sips model had the best fit for the adsorption of copper ions onto organo-bentonite. For the kinetic data, the pseudo-second order model was superior to the pseudo-first order model. Thermodynamically, the adsorption of copper ions occurs via chemisorption and the process is endothermic (ΔH 0 >0), irreversible (ΔS 0 >0) and nonspontaneous (ΔG 0 >0).
MethodsX, 2019
The new Native Natural Bentonite (NNB) for adsorption of Pb(II) and Zn(II) ions from aqueous environments was investigated at 27 AE 1 0 C by in batch laboratory experiments. Chemical and mineralogical structure of the NNB adsorbent was characterized by XRF and cation exchange capacity (CEC). The effect of pH, metals concentration, adsorbent dose, and agitation time were also studied. Langmuir and Freundlich isotherm and the Giles classification isotherm were used for describing the equilibrium data. The results show that the NNB contains silica (SiO 2) and alumina (Al 2 O 3) as a major chemical compound. The maximum adsorption capacity (mg/g), based on Langmuir isotherm were 8.55 and 7.90 for Pb(II) and Zn(II), respectively. Pb(II) and Zn(II) removal efficiency was increasing by increasing the initial pH of solutions, adsorbent dose, and contact time. Therefore, the results of this study show that the equilibrium is reached slowly (180 min), indicating the adsorption sites are not well exposed. By increasing the initial metals ion concentration, the capacity of adsorption decreased and the uptake of Pb(II) and Zn(II) per unit weight of the adsorbent (mg/g) increased. The adsorption efficiency of Pb(II) was higher than Zn(II).
Cobalt and zinc removal from aqueous solution by chemically treated bentonite
The Environmentalist, 2007
Natural bentonite was treated by hydrochloric, nitric, and phosphoric acids followed by washing with sodium hydroxide in order to enhance its adsorption capacity. The sample that treated with hydrochloric acid followed by further treatment with NaOH showed the highest cation exchange capacity with a value of 51.20 meq/100 g. The zero-point of charge for this sample was found to be 4.50. Adsorption isotherms for both cobalt and zinc were fitted using Langmuir, Freundlich, and Redlich-Peterson and showed an adsorption capacity of 138.1 mg Co 2+ and 202.6 mg Zn 2+ per gram of treated sample.
Investigation of Adsorption of Cu (II) Heavy Metal with Bentonite
Bitlis Eren Üniversitesi Fen Bilimleri Dergisi, 2018
In this study, adsorption of undesirable Cu (II) ion with bentonite in industrial wastewater was investigated at different temperature, pH and time intervals. Adsorption experiments were started with an adsorbent amount of 0.5 grams. Optimum pH determination experiments were carried out in the first stage of the adsorption experiments. The optimum pH determined after the experiments was determined as 5.0. Adsorption rates and adsorbed metal ions concentration increased with increasing concentrations of starting Cu (II) ions up to 25 mg / L and 500 mg / L in a medium containing 0.5 g of adsorbent. In the isotherm studies, isotherms were plotted and isotherm constants were calculated and it was clearly observed that the adsorption system, Langmuir and Freundlich isotherms. When the Gibbs free energy (ΔG) values calculated at different temperatures are taken into consideration, it is observed that the Cu (II) ions have negative values, for 100 mg/L and lower especially at low concentrations, and thus the reactions take place spontaneously for these concentrations. The compatibility of the adsorption system with the Langmuir and Freundlich isotherms was investigated, and it was observed that the adenomatoid system adhered to Langmuir and Freundlich. Based on the results, it is concluded that the amount of metal retained on the surface increases with temperature increase. Values (n> 1) were obtained for the experiments performed at each concentration of Cu (II) ions (up to 500 mg / L at 25 mg / L).
Copper, Zinc and Nickel’s removal by bentonite clay: Case study in mono multicomponent systems
2019
The main purpose of this work is the Copper, Zinc and Nickel’s removal from mono and multi-metal ions aqueous solution using an Algerian bentonite without treatment. The bentonite is characterized using SEM, XRD and X-ray fluorescence. The effect of initial pH and contact time are studied. Under mono and multicomponent systems, the kinetic studies performed at pH 5, indicate that the adsorption follows a pseudo second order model. For both systems, the isotherm data are well correlated with Langmuir model. Whereas the maximum adsorption capacities follow the sequence’s order Cu > Zn > Ni. In the case of multicomponent system, the Cu(II), Zn(II) and Ni(II) adsorptions capacities (58.82, 19.53 and 6.56 mg/g) are lower than the obtained ones for the monocomponent system (58.48, 49.02 and 31.74 mg/g). In addition to that, a mutual competitive effect is observed. Zn(II) and Ni(II) ions adsorption is also inhibited by Cu(II) ions with no change in the maximum Cu(II) adsorption cap...
Copper (II) ions removal from aqueous solution using bentonite treated with ammonium chloride
American journal of physical chemistry, 2012
A raw bentonite, obtained from Maghnia (Western Algerian) was impregnated into 1M ammonium chloride solution and thermally treated in a furnace at 200 °C during one hour. This treatment has improved its removal capacity of copper from aqueous solutions to about 30 %. The performances of the copper adsorption of this new material, after its physicochemical treatment, were evaluated by quantitative analysis on the copper remaining in the solution. The interface phenomena of bentonite-Cu2+ aqueous solution adheres to the Langmuir and Freundlich models. The adsorption energy, calculated by using Dubinin-Radushkevich equation, has proved that the removal of copper with this clay material is an ion exchange process. Nevertheless, the thermal treatment of this clay has inhibited the temperature effect on the retention of copper ions. Thus, the kinetic law governing the copper adsorption described here is following a second order model.
Adsorptive removal of Ni and Cd by bentonite from aqueous system
Bentonite clay mineral rich in montmorillonite was characterized and evaluated for removal of Ni and Cd from aqueous solution by batch adsorption study. The variables which affect metal sorption capacity such as adsorbent dose, pH and initial concentration of metals on the extent of adsorption were investigated. The experimental data were fitted with Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich adsorption isotherms. The Langmuir and Freundlich adsorption isotherms were fitted the sorption data better than other isotherms. The Langmuir maximum monolayer adsorption capacity of bentonite was found to be 13.95 mg g-1 and 9.41 mg g-1 for Ni (II) and Cd (II), respectively. The study revealed that bentonite could be potentially used for removal of Ni (II) and Cd (II) ions from effluents laden with heavy metals.