Adsorption Properties Of Pb²⁺ On Amino Ion Exchange Fiber

Pb2+is one of the major heavy metal ion contaminations, which has caused seriousdamage on the environment and human health. Currently, some methods were used to treatthe wasterwater containing Pb2+including chemical precipitation, ion exchange, film,biologyical assorption, electrolysis method and etc. Ion exchange is an effective method todeal with lead. In this paper, removal of Pb2+form aqueous solution by amino ion exchangefiber (AIEF) was operated, and the adsorption influencing factors were studied, consideringstatic adsorption time, temperature, initial concentration, pH on adsorption performance.Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), EDS spectrumare used to obtained the fiber characterization.In order to exploration adsorption mechanism,study of thermodynamics and kinetics is necessary for understanding the molecularmechanism of adsorption.The effect of contact time, initial Pb2+concentration and pH value was investigated.The results showed that the maximum adsorption capacity of AIEF was429.3mg g-1at pH5.0. The adsorption capacity increased with Pb2+concentration.Adsorption isotherms at various temperatures were obtained. Langmuir, Freundlich,Temkin models were adopted and the equilibrium data fitted better with Langmuir isotherm.The constants of these models indicated a monolayer adsorption process including bothphysisorption and chemisorption. The values of thermodynamic parameters, including Δ H,Δ G and Δ S, suggested that the adsorption of Pb2+on AIEF was a spontaneous,entropy-driven and endothermic process.Kinetics curves showed two stages in Pb2+adsorption, fast and adsorption equilibriumperiods and90%Pb2+removal was realized in the first stage. Kinetics data for adsorptionof Pb2+from aqueous solutions were in good agreement with pseudo-first order at firstadsorption stage and pseudo-second rate equation for the whole adsorption process. Thefirst stage can well meet the Elovich apparent kinetics, indicating AIEF rapid adsorption ofPb2+mainly stage at AIEF surface.