Separation of Cu2+ and Pb2+ by tetraethylenepentamine-modified sugarcane bagasse fixed-bed column: selective adsorption and kinetics

Tetraethylenepentamine-modified sugarcane bagasse (SCB) was prepared to improve its adsorption capacity and selectivity toward Cu2+. Adsorption performances of the modified sorbent for Cu2+ were studied in batch system. Separation of Cu2+ from Pb2+ by the modified sorbent fixed-bed column were studied under dynamic system with initial molar concentration ratio ranging from 1:1 to 1:100. The amount of Cu2+ and Pb2+ adsorbed on the saturated column was calculated by the elution curve. Batch experimental results showed that the adsorption capacity of the sorbent for Cu2+ increased from 0.12 to 0.21 mmol g(-1) after modification. Dynamic adsorption results showed that the modified SCB had higher adsorption affinity toward Cu2+ than Pb2+. 0.07 mmol g(-1) of adsorbed Pb2+ was pushed off by Cu2+ during the competitive adsorption process at The breakthrough curves and adsorption kinetics of Cu2+ in the column could be fitted well by the Yoon-Nelson and modified Yoon-Nelson model, respectively. According to the elution curve, the amount of Cu2+ adsorbed on the fixed-bed column were 0.16, 0.16 and 0.15 mmol g(-1), while that of Pb2+ were 0.0016, 0.0051 and 0.0094 mmol g(-1) when increased from 1:1 to 1:10 and 1:100. Cu2+ could be selectively adsorbed and separated from Pb2+ by using the modified sorbent fixed-bed column.