普罗维登斯菌和希瓦氏菌对Pt(Ⅳ)的吸附特性

摘要

研究了普罗维登斯菌和希瓦氏菌两种微生物对 Pt(Ⅳ)的吸附特性.pH 和离子强度条件优化实验结果表明,pH=2.0时吸附效果较好,吸附量分别为58.62和72.20 mg/g;随着离子强度的增加,普罗维登斯菌对Pt(Ⅳ)的吸附量增加而希瓦氏菌却降低;Pt(Ⅳ)和Pd(Ⅱ)共存时,两种微生物吸附剂均优先吸附 Pd(Ⅱ).动力学和等温吸附实验结果表明,普罗维登斯菌吸附 Pt(Ⅳ)的过程更符合拟二级动力学模型和Langmuir等温模型,说明化学吸附是该过程的限速步骤,且为单分子层吸附,其理论最大吸附量为136.10 mg/g.因此,以上研究结果表明,普罗维登斯菌和希瓦氏菌可以吸附回收溶液中的Pt(Ⅳ)离子.%The biosorption characteristic of Pt(Ⅳ)onto Providencia vermicola and Shewanella oneidensis MR-1 was reported.Firstly,the effects of pH and ionic strength on the adsorption by two microorganisms were studied.It was found that the adsorption capacity was highest at pH 2.0 and the adsorption capacities were 58.62 and 72.20 mg/g,respectively.With the increase of ionic strength,the adsorption in Providencia vermicola enlarged but declined in Shewanella oneidensis.In the binary solution of Pt(Ⅳ)and Pd(Ⅱ),both microbial adsorbents preferentially adsorbed Pd(Ⅱ).The results of kinetic and equilibrium experiments showed that the process of Pt(Ⅳ)adsorption onto Providencia vermicola was more consistent with the pseudo-second-order kinetic model and Langmuir isotherm model,indicating that chemical adsorption is the rate limiting step during the adsorption process and belongs to single molecular layer adsorption.The maximum adsorption capacity calculated from Langmuir model is 136.10 mg/g.Based on these results,Providencia vermicola and Shewanella oneidensis MR-1 could be used as adsorbents for recovering Pt(Ⅳ)ions from the solution.