3种微生物吸附剂对低浓度Cd^(2+)的吸附特性研究  

Adsorptive Capacity and Kinetics of Cd^(2+) with 3 Biosorbents

作　　者：李欣[1,2] 谭周亮[1] 周后珍[1] 张银莲[1] 李旭东[1] 

机构地区：[1]中国科学院成都生物研究所,四川成都610041 [2]中国科学院研究生院,北京100049

出　　处：《环境科学与技术》2011年第12期7-13,共7页Environmental Science & Technology

基　　金：中国科学院知识创新工程重要方向项目(KSCX2-YW-G-055;KSCX2-YW-G-071);国家"863"重大项目课题(2008AA06A409);四川省科技厅项目资助(07SG%005-001)

摘　　要：从铬鞣污泥和活性污泥中筛选到3种微生物TP、MY和TQ,将其制备成微生物吸附剂对低浓度Cd2+的吸附特性进行研究。结果表明:在Cd2+初始浓度为5.0 mg/L的溶液中,吸附剂TP和MY最佳投加量和pH值为1.0 mg/L和7.0;TQ为2.0 mg/L和4.0 mg/L。TP、MY和TQ的最佳吸附温度是20℃。等温方程研究说明TP和MY对Cd2+的吸附符合Langmuir等温模型,TQ对D-R吸附等温模型拟合较好;3种吸附剂对低浓度Cd2+的吸附过程均符合拟二级动力学模型,颗粒内扩散模型拟合表明TP和TQ吸附过程分为外表面吸附和孔内缓慢吸附,MY为线性吸附阶段。热力学研究表明其对Cd2+的吸附反应均能自发进行。红外光谱分析表明,吸附剂表面的酰胺基中C-N键和N-H键、醇羟基O-H键、羧基-C(=O)O-H和烃基C-H键在吸附Cd2+过程中发挥主要作用。实验结果证明3种吸附剂对水体中低浓度Cd2+有较好的吸附作用。Mechanism and function of Cd2＋ sorption by biosorbents such as TP, MY and TQ were studied, which were screened from chrome tanned sludge and activated sludge. Results indicated that the optimal pH value and mass concentration of TP and MY were 7.0 and 1.0 g/L, and TQ was 4.0 and 2.0 g/L in initial concentration of 5.0 mg/L Cd2＋ solutions, and the optimal temperature was 20℃. TP and MY fit well with Langmuir isotherm model, and TQ fits well with D-R isotherm model. Actual sorption process was identical relatively with pseudo-second-order Lagergren model and was depicted the spontaneous nature of biosorption process by thermodynamic parameters. FTIR data indicated that the functional group of amido, hydroxyl group, carboxyl and hydroxyl played a principal role in the adsorption. Results showed that the removal of Cd2＋ was significant by 3 adsorbents to low concentration Cd2＋ aqueous solution, with the order of the maximum adsorption capacity as TP, MY and TQ.

关 键 词：生物吸附 Cd2+ 等温吸附模型 动力学 热力学 

分 类 号：X703.1[环境科学与工程—环境工程]