摘要
通过批次吸附实验及介观和谱学等表征方法,研究了大肠杆菌(E.coli)粉末对水体中U(Ⅵ)的富集行为和吸附模型,并对其作用产物进行了详细分析.结果表明:大肠杆菌对初始浓度为50mg/L U(Ⅵ)溶液(p H=5)的吸附容量可达到276.89mg/g.Langmuir等温模型和准二级动力学方程能较好的描述其吸附过程.FTIR、SEM-EDS、XRD分析结果表明:在与水体中U(VI)作用后,大肠杆菌表面检测出UO22+的红外特征峰(876.16cm-1)和U的能谱吸收峰(结合能=2.4~4.4ke V).UO_2^(2+)主要与菌体表面的烷基、氨基、羧基、分子间氢键发生作用,重点与PO_2-、P(OH)_2、PO_4^(3-)以及PO_3^-等含P基团进行络合配位,最终产物以Ca U(PO_4)_2、Ca(UO_2)_2(PO_4)_2·x H_2O、Na UO_2(PO_3)_3等铀的磷酸盐形式存在.
The accumulation behavior, adsorption model and adsorptive product for dryEscherichia coli powder adsorbing U（Ⅵ） were investigated by the batch absorption experiment, mesoscopic and spectroscopy characterization methods. The maximum biosorption capacity was 276.89mg/g when pH was 5and the initial U（Ⅵ） concentration was 50mg/L. The adsorption process could be well described by Langmuir isothermal model and the pseudo-second order model. FTIR （876.16cm-1, UO22＋）, SEM-EDS （2.4~4.4keV, U） and XRD results certified that U（Ⅵ） were successfully adsorbed on the cell surface of Escherichia coli. UO22＋ mainly reacted with alkyl, amino, carboxyl and intermolecular hydrogen bond on the surface ofEscherichia coli,especially complexing with P containing groups （PO2-, P（OH）2, PO43- and PO3-）. After adsorption, U（Ⅵ） were transformed to uranium containing phosphate, such as CaU（PO4）2、Ca（UO2）2（PO4）2？xH2O and NaUO2（PO3）3.
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2016年第6期1780-1787,共8页
China Environmental Science
基金
国家重点基础研究发展计划(973)项目(2014CB846003)
国家自然科学基金(41502316
41272371
41472310)
核废物与环境安全国防重点学科实验室预先研究基金项目(15yyhk11)
西南科技大学博士基金(15zx7109)
