一种改性微生物吸附剂的制备及其对镉离子的吸附特性  

Preparation of a modified microbial adsorbent and its adsorption characteristics for Cd

作　　者：徐韶足 王瑶 毕文龙 周珺 陈雯莉[2] XU Shaozu;WANG Yao;BI Wenlong;ZHOU Jun;CHEN Wenli(College of Resources and Environment,Shanxi Agricultural University,Taigu 030801;State Key Laboratory of Agricultural Microbiology,Huazhong Agricultural University,Wuhan 430070)

机构地区：[1]山西农业大学资源环境学院,太谷030801 [2]华中农业大学微生物学国家重点实验室,武汉430070

出　　处：《环境科学学报》2021年第4期1342-1350,共9页Acta Scientiae Circumstantiae

基　　金：山西省青年科技研究基金(No.201901D211355);山西省优秀博士来晋工作奖励资金(No.K271999051);山西省重点研发计划项目子课题(No.201903D211012)。

摘　　要：改性生物吸附剂具有更好的重金属离子去除能力,成为近年来研究热点.本研究通过向菌株拉乌尔菌Raoultella sp. X13生长培养基中添加特定盐获得改性吸附剂,并研究了其镉离子(Cd^(2+))吸附特性.研究结果表明,相比原始菌体X13,经KCl、K_(2)SO_(4)、KH_(2)PO_(4)、(NH_(4))_(2)SO_(4)和NH4Cl改进的生长培养基制备的吸附剂提高了对Cd^(2+)吸附效果.其中,NH4Cl改性的拉乌尔菌Raoultella sp. X13(命名为R5-1)对Cd^(2+)吸附能力显著增加,达66.40 mg·g^(-1),增加了47.30%.这一显著变化主要依赖于生长代谢引起的细胞表面结构变化.Cd^(2+)吸附特性研究结果表明生物吸附过程受溶液pH、初始金属浓度和接触时间的影响.Langmuir等温线模型和伪二级动力学模型更加符合吸附剂R5-l对Cd^(2+)的吸附数据. FTIR分析表明R5-l表面存在多种功能位点并可能参与金属离子的结合,例如-OH,-CH_(2),N-H,-COO,磷酸盐或硫酸盐等官能团.模拟实验结果表明吸附剂R5-l可以有效修复废水中多种金属离子.因此,本研究获得的改性吸附剂R5-l可以作为重金属Cd^(2+)的潜在微生物修复剂,并为高效,简便,环保地制备改性吸附剂提供一定的参考.Modified adsorbents have become a research focus because of its excellent capacity to remove heavy metal ions. In this study, a modified adsorbent was prepared by applying different salts in the culture media of Raoultella sp. X13, and the adsorption characteristics of modified adsorbent to Cd^(2+) were studied. The results showed that Cd^(2+) adsorption capacities of Raoultella sp. X13 were improved in the presence of KCl, K_(2)SO_(4), KH_(2)PO_(4),(NH_(4))_(2)SO_(4), and NH4Cl. Interestingly, the maximum adsorption capacity of Raoultella sp. X13(named R5-1) modified by NH4Cl for Cd^(2+) could reach 66.40 mg·g^(-1), which increased by 47.30% compared with the control owing to the surface structure change of Raoultella sp. X13. different parameters, such as initial pH, contact time, and initial Cd^(2+) concentration, affected the adsorption capacity of Cd^(2+). The Cd^(2+) adsorption behavior by R5-1 was well fitted with Langmuir isotherm model and the pseudo-second-order kinetic model. FTIR analysis results showed that there are multiple functional sites on the surface of R5-l for the binding of Cd^(2+) ions, such as -OH,-CH_(2),N-H,-COO,phosphate or sulfate functional groups. Simulation results showed that the biosorbent R5-l could efficiently remove a variety of heavy metal ions from wastewater. Therefore, the modified biosorbent R5-l can be used as a potential material for the remediation of Cd^(2+) pollution. This study provides a method for the preparation of modified biosorbents that are efficient, simple, and environmental-friendly.

关 键 词：生物吸附剂 重金属镉污染 生物吸附 拉乌尔菌 

分 类 号：X703[环境科学与工程—环境工程] X172