棘孢曲霉(Aspergillus aculeatus)对Pb^(2+)和Cd^(2+)的吸附特征

Characters of Pb^(2+) and Cd^(2+) biosorption by Aspergillus aculeatus

为了研究棘孢曲霉(Aspergillus aculeatus)对溶液中Pb^(2+)和Cd^(2+)吸附过程的特征,分别从动力学、热力学和吸附等温线三方面进行了实验,同时还研究了pH、温度、时间、重金属离子起始浓度和吸附剂用量对吸附过程的影响。等温吸附过程可以用Langmuir方程来描述。在实验设定条件下,棘孢曲霉对Pb^(2+)和Cd^(2+)最大吸附量分别为71.2 mg/g和59.8 mg/g;动力学实验数据很好的符合二级动力学方程,吸附达到平衡的时间为3 h;热力学实验数据显示该吸附过程为自发的、吸热的过程。

The isotherms, kinetics, thermodynamics and desorption rates of Pb（Ⅱ） and Cd（Ⅱ） biosorption by Aspergillus aculeatus were investigated in a batch system for the character of the biosorption. The effects of pH, initial metal ions concentration, biomass dose, contact time and temperature on the biosorption were also studied. The adsorption was well described by Langmuir model, the biosorption capacity of Aspergillus aculeatus biomass for Pb（Ⅱ） and Cd（Ⅱ） was found to be 71.2 mg/g and 59.8 mg/g, respectively. The results of the kinetic studies of all metal ions at different temperatures showed that the adsorption rate followed the pseudo second-order kinetics well, the adsorption reached equilibrium in 3h. The thermodynamics constants of the adsorption process showed that the biosorption was endothermie and spontaneous.