球衣菌(Sphaerotilus natans)吸附Ag^+的影响因素及其机理  

MECHANISM OF Ag^+ BIOSORPTION BY SPHAEROTILUS NATANS

作　　者：刘峰[1] 许旭萍[1] 沈雪贤[1] 

机构地区：[1]福建师范大学生命科学学院,福州350108

出　　处：《环境化学》2011年第7期1259-1265,共7页Environmental Chemistry

基　　金：福建省自然科学基金资助项目(X0750027)

摘　　要：采用球衣菌(Sphaerotilus natans)为生物吸附剂,研究了初始离子浓度、吸附剂用量、菌龄、pH值、温度和吸附时间等因素对其吸附硝酸银溶液模拟废水中Ag+的影响及其吸附机理.结果表明,球衣菌在初始Ag+14 m.gL-1、吸附剂用量0.2.gL-1、菌龄32 h、pH 8、温度30℃、吸附时间60 m in的优化条件下,对Ag+的吸附率为71.75%,吸附量为50.23 m.gg-1;该吸附过程是一个快速的过程,在吸附5 m in时,吸附量已达总吸附量的91%,并且以被动吸附为主;吸附动力学符合准二级动力学方程.透射电镜观察和红外光谱分析显示,球衣菌细胞表面的活性基团与Ag+发生络合反应,同时还有少量Ag+通过主动吸收过程进入活细胞内.Using a strain of Sphaerotilus natans as biosorbent,the factors for Ag＋ adsorption in simulated waste water containing AgNO3,such as the initial concentration of Ag＋,biomass concentration,the culture time of the bacterium,pH value,temperature and the adsorption time were determined,and the adsorption mechanism was further discussed.The results showed that the maximum adsorption capacity for Ag＋ on S.natans reached 50.23 mg·g-1 dry biomass,and the adsorption rate was 71.75% under the optimal conditions with the Ag＋ concentration of 14 mg·L-1,0.2 g·L-1 biomass precultured for 32 h,incubation temperature of 30 ℃,pH 8,and incubation time of 60 min.The process was fast and passive.In the initial 5 minutes,the adsorption of Ag＋ reached 91% of the total capacity.The dynamic model of Ag＋ adsorption was consistent with the pseudo-second order kinetic model.TEM and IR spectrum indicated that the main biosorption mechanism included the interaction of Ag＋ with the active groups on the cell surface of S.natans,as well as the process of trace Ag＋ entering live cells.

关 键 词：生物吸附剂 球衣菌(Sphaerotilus natans) Ag+ 因素 吸附机理 

分 类 号：X703[环境科学与工程—环境工程]