The Batch And Dynamic Research Of Pb(Ⅱ) Removal From Aqueous Solutions Onto Macroreticular Resin

Lead is hard to biodegradable, easily enriched in the food chain, having caused greatthreat to the natural ecological environment and human health. In order to solve the leadpollution, effective techniques and methods have been exploring to remove lead aroundthe world. Among them, the ion exchange technology with high adsorption capacity is tobe the main direction of heavy metal treatment. D001resin is cheap and commercialproduced, but less used in heavy metal removal. The purpose of this work was to evaluatethe potential of lead removal in aqueous solution by D001resin.In the static experiments, we first investigate the single factor influence on D001resin to remove lead, such as the initial pH, solid-liquid ratio, initial lead ionsconcentration, reaction time and reaction temperature. And on this basis, the optimumreaction conditions were determined. Then we explored the effect of other metal ions onthe lead removal by D001resin and the regeneration of D001resin. The experimentalresults show that, a sorbent amount0.04g in80ml aqueous solutions for200mg/L Pb(II),contact time300min, at pH3, the maximum removal efficiency reaches93%, and thecorresponding adsorption capability is360mg/g. In the competitive adsorption of binarysystem, the presence of Al3+has obvious negative effect on Pb2+removal by D001resin.In order to investigate the kinetics of adsorption, three kinetic models, Pseudo firstorder equation. Pseudo second order equation and intra-particle diffusion process wereemployed. We found that the process of D001resin to remove lead conforms to thepseudo first order kinetics model. Isothermal experimental data are evaluated withLangmuir and Freundlich isotherms, the results show that the Langmuir isotherm fittingis more appropriate. The thermodynamic parameters of the adsorption for lead ions, H0,S0, G0, indicated the adsorption process is spontaneous and endothermic.In the dynamic experiments, the performance of the system was evaluated to assessthe effect of various process variables, viz., of resin dosage (bed height), hydraulicloading rate and initial feed concentration on breakthrough time and adsorption capacity.Then the study of regeneration was carried at the optimal operation parameters of thefixed bed reactor. The Yoon-Nelson model was used to analyze the experimental data and the model parameters were evaluated. The results show that breakthrough time of bedwas found to increase with an increase in the value of adsorption dose and with adecrease in the value of initial concentration or flow rate. There is a good agreement ofthe experimental breakthrough time with the model. The regenerated resin can be usedrepeatedly without significant loosing the adsorption capacity. The D001resin has greatpromising in the treatment of wastewater containing lead with economic and goodperformance.