Yue Zheng-Bo, Li Qing, Li Chuan-chuan, Chen Tian-hu, Wang Jin
School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, China.
School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, Anhui 230009, China.
Bioresour Technol. 2015 Oct;194:399-402. doi: 10.1016/j.biortech.2015.07.042. Epub 2015 Jul 21.
Extracellular polymeric substances (EPS) play an important role in the treatment of acid mine drainage (AMD) by sulfate-reducing bacteria (SRB). In this paper, Desulfovibrio desulfuricans was used as the test strain to explore the effect of heavy metals on the components and adsorption ability of EPS. Fourier-transform infrared (FTIR) spectroscopy analysis results showed that heavy metals did not influence the type of functional groups of EPS. Potentiometric titration results indicated that the acidic constants (pKa) of the EPS fell into three ranges of 3.5-4.0, 5.9-6.7, and 8.9-9.8. The adsorption site concentrations of the surface functional groups also increased. Adsorption results suggested that EPS had a specific binding affinity for the dosed heavy metal, and that EPS extracted from the Zn(2+)-dosed system had a higher binding affinity for all heavy metals. Additionally, Zn(2+) decreased the inhibitory effects of Cd(2+) and Cu(2+) on the SRB.
胞外聚合物（EPS）在硫酸盐还原菌（SRB）处理酸性矿山废水（AMD）过程中发挥着重要作用。本文以脱硫脱硫弧菌作为受试菌株，探究重金属对EPS成分及吸附能力的影响。傅里叶变换红外（FTIR）光谱分析结果表明，重金属并未影响EPS官能团的类型。电位滴定结果显示，EPS的酸度常数（pKa）分为3.5 - 4.0、5.9 - 6.7和8.9 - 9.8三个范围。表面官能团的吸附位点浓度也有所增加。吸附结果表明，EPS对添加的重金属具有特异性结合亲和力，且从添加Zn(2+)的系统中提取的EPS对所有重金属具有更高的结合亲和力。此外，Zn(2+)降低了Cd(2+)和Cu(2+)对SRB的抑制作用。
