通过驯化培养得到了以硫酸盐还原菌(S RB )为优势菌属的活性颗粒污泥,研究了微氧条件(氧浓度为0.6~1.0 mg/L)下其对废水中U(Ⅵ)的去除性能,利用傅里叶红外光谱(FTIR)、扫描电镜(SEM )和X射线能谱(EDS )分析了其对U (Ⅵ)的去除机理,采用连续提取法考察了铀在颗粒污泥上的沉积形态。实验结果表明,微氧条件下SRB颗粒污泥结合并转化U (Ⅵ)的过程主要分为两步:初期(前30 min)吸附和后期微生物还原沉淀作用,SRB颗粒污泥对U(Ⅵ)的去除率达98.89%。FTIR、SEM 和EDS分析表明,颗粒污泥表层上酰胺基、羧基、羟基、磷酸基等均参与了对U (Ⅵ)的沉积,同时 Na^+、M g^2+等与U O2^+2存在离子交换作用。形态分析表明,在颗粒污泥上,铀主要以残渣态形式沉积,生物有效性差,可迁移能力弱,不易造成二次污染。
T he bioremediation behavior and mechanism of sulfate reducing bacteria (SRB) granular sludge which was artificially domesticated were studied .U(Ⅵ) removal by SRB granular sludge was investigated under micro‐aerobic condition with the concen‐tration of oxygen 0.6‐1.0 mg/L ,then the removal mechanism was analyzed with FTIR , SEM and EDS ,and finally the deposit morphology of uranium was studied with the se‐quential extraction procedure .The results show that U (Ⅵ ) removal by SRB granular sludge mainly occurs following a 2‐step process w hich is initial adsorption (the first 30 min) and microbial reduction process .The ultimate removal rate of U (Ⅵ ) reaches 98.89% .Analyses of FTIR ,SEM and EDS indicate that groups‐amide group ,carbox‐yl ,hydroxyl and phosphoric acid group coming from the surface of SRB granular sludge are involved in uranium deposition .Ion exchange happens between Na+ or Mg2+ and UO2+2 .Finally ,U(Ⅵ) mainly deposites on granular sludge in the form of residual state that has poor bioavailability ,bad migratory aptitude and less secondary pollution .