毛木耳对Cd~(2+)、Cu~(2+)、Pb~(2+)、Zn~(2+)生物吸附的动力学和吸附平衡研究

以毛木耳(Auriculariapol ytricha)子实体为生物吸附材料,研究起始pH值、反应时间、重金属浓度这3个因素对毛木耳子实体吸附Cd2+、Cu2+、Pb2+、Zn2+的影响及其吸附特性.结果表明,pH是影响毛木耳子实体吸附重金属离子的主要因素,最适起始pH值为5;在10mg·L-1重金属浓度下,毛木耳子实体对Cd2+、Cu2+、Pb2+、Zn2+的最大吸附率分别为94.12%、96.22%、99.94%、99.19%;准二阶动力学模型比准一阶动力学模型能更好地描述毛木耳子实体对4种重金属的吸附过程;Langmuir等温模型能较好地拟合毛木耳子实体对4种重金属的等温吸附过程;毛木耳子实体对Cd2+、Cu2+、Pb2+、Zn2+的最大吸附量分别为10.09、8.36、23.57和3.64mg.g-1;毛木耳子实体吸附Cd2+、Cu2+、Zn2+的化学反应机理可能为离子交换反应.

Kinetics and equilibrium of biosorption of Cd2+,Cu2+,Pb2+,Zn2+ by macrofungus(Auricularia polytricha) biomass

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.