真菌吸附重金属离子的研究

Study on the Biosorption of Heavy Metals by Fungi

利用黑曲霉和简青霉制备生物吸附剂,研究了它们对重金属Pb2+离子和Cd2+离子的吸附、解吸行为以及实验条件对吸附的影响,包括吸附剂用量、溶液pH值、吸附时间以及共存离子等因素.结果表明,黑曲霉和简青霉吸附Pb2+离子的最适pH值均为5,吸附Cd2+离子时均为3.二者对Pb2+离子的吸附均在4 h达到平衡,吸附量分别为29.07 mg.g-1和36.65 mg.g-1.Cd2+离子吸附也在约4 h达到最大吸附量,分别为26 mg.g-1和26.5mg.g-1.溶液中Zn2+离子和Cd2+离子的存在都会降低Pb2+离子的吸附量.2种吸附剂对Pb2+离子的吸附都符合Langmuir等温线模型,而对Cd2+离子的吸附都较为符合Freundlich等温线模型.1 mol/L HNO3对吸附有Pb2+离子的黑曲霉和简青霉进行解吸,解吸率分别可达77.4%和92.3%.

This paper studied the biosorption of heavy metal ions Pb^2 ＋ and Cd^2 ＋ by two kinds of biosorbents prepared by Aspergillus niger and Penicillium simplicissimum respectively, which included biosorption, desorption and the effects of the does of sorbent, pH, contact time and co-ions on the biosorption, The results showed that the optimum adsorption pH for Pb^2＋ and Cd^2＋ was individually 5 and 3 using dead A, niger or P. simplicissimum, Biosorption equilibrium was all established within about 4 h for Pb^2＋ and Cd^2＋ adsorbed by A. niger and P. simplicissimum. The uptake were 29.07 mg· g^- 1 and 36.65 mg· g^- 1 for Pb^2 ＋ , 26 mg· g^-1 and 26.5 mg· g^- 1for Cd^2 ＋ . The uptake of Pb^2 ＋ decreased when Zn^2＋ and Cd^2＋ existed. The adsorption data was all fit to Langmuir isotherm model for Pb^2＋ and Freundlich model for Cd^2＋ . The desorption rates of Pb^2＋ by 1 mol· L^- 1HNO3 were calculated, as 77.4 % and 92.3 % for A, niger and P. simplicissimum.