探索了产菌核米曲霉Aspergillus oryzae G15对水溶液中Cu(Ⅱ)的吸附特性和机理。课题以G15菌株的菌丝体及菌核作为吸附剂,研究吸附平衡时间及溶液pH值对吸附过程的影响,并采用Langmuir和Freundlich等温方程对吸附数据进行拟合。实验还对铜离子吸附前后的菌丝体和菌核进行扫描电镜(SEM)观察及X射线光电子能谱(XPS)分析。结果表明,菌丝体和菌核吸附铜离子的平衡时间为120min;在pH为5.0时,菌丝体和菌核对Cu(Ⅱ)的吸附效果达到最佳;且吸附过程符合Langmuir吸附模型(R2分别为0.9741和0.9906),由方程所得的菌丝体及菌核最大吸附量分别为35.84和73.53mg/g。通过SEM观察结果可知铜处理导致吸附剂表面结构发生变化,菌丝体空隙增加,更有利于吸附;XPS全谱图表明菌丝体和菌核可能通过表面官能团络合和离子交换对Cu(Ⅱ)进行吸附。
In order to investigate the biosorption property of copper(Ⅱ) from aqueous solutions with sclerotigenic Aspergillus oryzae G15, the impacts of pH and contact time on Cu uptake were studied. The results indicated that the optimum solution pH for biosorption was 5.0, and the biosorption process reached equilibrium for 120 rain. The isotherm studies indicated that the Langmuir model (with R2 values of 0. 974 1 and 0. 990 6, respectively) was able to describe the absorption process of mycelia and sclerotia, with the maximum theoretical sorption capacities of 35.8LI and 73.53 mg/g, respectively. Furthermore, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) studies were carried out to elucidate the adsorption mechanisms. The results indicated that the functional groups complexation and cation exchange adsorption played significant role in Cu( Ⅱ) biosorption.