-The adsorption characteristics of cadmium and nickel onto expanded perlite from aqueous solution have been investigated with respect to changes in pH of solution, adsorbent dosage, contact time and temperature of the solution. The maximum removal efficiency of Cd (II) is 88.8% at pH 6 and exposure to 10 g/L expanded perlite, while for Ni (II), it is 93.3% at the same pH and exposure to 8 g/L adsorbent. For the adsorption of both metals, the Freundlich isotherm model fitted the equilibrium data better than the Langmuir isotherm model. Experimental data are also evaluated in terms of kinetic characteristics of adsorption and it was found that the adsorption process for both metal ions follows well pseudo-second-order kinetics. Thermodynamic functions, the change of free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) of adsorption are also calculated for each metal ion. The results show that the adsorption of these metal ions on expanded perlite is feasible and exothermic at 20-50°C.
A B S T R A C TThe study tries to determine the optimal condition to achieve the maximum Cr(VI) removal in the biosorption process from aqueous solution using acid-treated date palm fiber as the biosorbent. Three factors including initial pH, initial Cr(VI) concentration, and biosorbent dosage were optimized using response surface methodology. Maximum Cr(VI) removal was 95% at the optimum condition of initial pH 3.3, initial Cr(VI) concentration 180 (mg/L), and biosorbent dosage of 0.8% (w/v). The kinetic study was done to acquire a deeper understanding of the mechanism of biosorption process and its results showed that the pseudosecond-order models controlled the process. Isotherm study showed that Langmuir model described the experimental data thoroughly.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.