徐韶足,王瑶,毕文龙,周珺,陈雯莉.一种改性微生物吸附剂的制备及其对镉离子的吸附特性[J].环境科学学报,2021,41(4):1342-1350
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 Cd2+
- 基金项目：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）
- 徐韶足
- 山西农业大学资源环境学院, 太谷 030801
- 王瑶
- 华中农业大学微生物学国家重点实验室, 武汉 430070
- 毕文龙
- 山西农业大学资源环境学院, 太谷 030801
- 周珺
- 山西农业大学资源环境学院, 太谷 030801
- 陈雯莉
- 华中农业大学微生物学国家重点实验室, 武汉 430070
- 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（Cd2+）吸附特性.研究结果表明，相比原始菌体X13，经KCl、K2SO4、KH2PO4、（NH4）2SO4和NH4Cl改进的生长培养基制备的吸附剂提高了对Cd2+吸附效果.其中，NH4Cl改性的拉乌尔菌Raoultella sp. X13（命名为R5-1）对Cd2+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.Cd2+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Cd2+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，—CH2，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Cd2+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.
- Abstract：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 Cd2+ were studied. The results showed that Cd2+ adsorption capacities of Raoultella sp. X13 were improved in the presence of KCl, K2SO4, KH2PO4, (NH4)2SO4, and NH4Cl. Interestingly, the maximum adsorption capacity of Raoultella sp. X13 (named R5-1) modified by NH4Cl for Cd2+ 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 Cd2+ concentration, affected the adsorption capacity of Cd2+. The Cd2+ 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 Cd2+ ions, such as -OH,-CH2,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 Cd2+ pollution. This study provides a method for the preparation of modified biosorbents that are efficient, simple, and environmental-friendly.
