分离自活性污泥的硫酸盐还原菌用于铅锌冶炼渣重金属污染修复

【背景】从活性污泥中分离出一类具有硫酸盐还原能力的菌株,探讨了其用于铅锌冶炼渣重金属污染修复的可行性。【目的】研究硫酸盐还原菌(Sulfate reducing bacteria)对铅锌冶炼渣中重金属的固化作用。【方法】将从活性污泥中分离出的硫酸盐还原菌接种到铅锌冶炼渣中进行修复,采用X射线衍射、Tessier、电感耦合等离子体发射光谱仪检测、高通量测序等方法进行实验。检测铅锌冶炼渣中矿物组成,以及修复过程中重金属化学形态、各金属离子浓度和微生物群落结构的变化。【结果】修复实验表明,体系中电位降低、pH值提高、各重金属稳定态增加、离子浓度降低且微生物群落结构变化显著,硫酸盐还原菌成为优势菌群。【结论】接种硫酸盐还原菌后铅锌冶炼渣中的重金属原位固化效果显著,从而降低生物可利用性,将恶性循环变为良性循环,所以硫酸盐还原菌可用作重金属污染修复的固化药剂。

Remediation of heavy metal pollution by sulfate reducing bacteria (SRB) isolated from activated sludge in lead-zinc smelter slag

Background] A group of microorganisms with sulfate reduction ability were isolated from activated sludge, and their feasibility of heavy metal pollution remediation of lead-zinc smelter slag was also explored. Objective] To study the solidification of heavy metals in lead-zinc smelter slag by sulfate reducing bacteria (SRB) obtained. Methods] Sulfate-reducing bacteria isolated from activated sludge were inoculated into lead-zinc smelting slag for remediation. X-ray diffraction, Tessier, inductively coupled plasma optical emission spectrometer and high-throughput sequencing techniques were used in remediation experiments. The mineral composition of lead-zinc smelter slag, the chemical fractions of heavy metals, the concentration of metal ions and the structure of microbial community were detected during the remediation process. Results] The results of remediation experiments showed that the redox potential decreased, the pH increased, the stable state of heavy metals increased, the ion concentration decreased and the microbial community structure changed significantly. Sulfate reducing bacteria became the main microbial community. Conclusions] By inoculating sulfate reducing bacteria into lead-zinc smelter slag, the heavy metals could be solidified in situ significantly, thus reducing the bioavailability and improving environment. Sulfate reducing bacteria can be used as solidifying agents for remediation of heavy metal contaminated sites.