Kinetics and equilibrium of biosorption of Cd2+,Cu2+,Pb2+,Zn2+ by macrofungus(Auricularia polytricha) biomass
毛木耳对Cd2+、Cu2+、Pb2+、Zn2+生物吸附的动力学和吸附平衡研究

Using Auricularia polytricha as a biosorbent, we studied the effects of different factors, including contact time, pH, and heavy metal concentrations, on adsorption of Cd2+, Cu2+, Pb2+, Zn2+ by the biosorbent. Results showed that pH was the most influent factor for the biosorption. The optimum initial pH value was 5 for the maximum adsorption. With metal concentrations of 10 mg L-1, the maximum removals of Cd2+, Cu2+, Pb2+, Zn2+ by A. polytricha were 94.12%, 96.22%, 99.94%, and 99.19%, respectively. The pseudo-second-order kinetics model was better to characterize the biosorption processes of the metals than the pseudo-first-order kinetics model. Langmuir isotherm model was used to fit the equilibrium data successfully. The maximum biosorption capacities of A. polytricha were 10.09, 8.36, 23.57, and 3.64 mg g-1, respectively, for Cd2+, Cu2+, Pb2+, Zn2+. Ion exchange may be the main mechanism for the biosorption of Cd2+, Cu2+, Zn2+ by the biosorbent.