Lv Ying, Tang Chuiyun, Liu Xingyu, Zhang Mingjiang, Chen Bowei, Hu Xuewu, Chen Susu, Zhu Xuezhe
National Engineering Research Center for Environment-Friendly Metallurgy in Producing Premium Non-ferrous Metals, GRINM Group Co., Ltd., Beijing, China.
School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing, China.
Front Microbiol. 2021 Dec 13;12:770206. doi: 10.3389/fmicb.2021.770206. eCollection 2021.
Uranium pollution in tailings and its decay products is a global environmental problem. It is of great significance to use economical and efficient technologies to remediate uranium-contaminated soil. In this study, the effects of pH, temperature, and inoculation volume on stabilization efficiency and microbial community response of uranium tailings were investigated by a single-factor batch experiment in the remediation process by mixed sulfate-reducing bacteria (SRB) and phosphate-solubilizing bacteria (PSB, sp. grinm-12). The results showed that the optimal parameters of microbial stabilization by mixed SRB-PSB were pH of 5.0, temperature of 25°C, and inoculation volume of 10%. Under the optimal conditions, the uranium in uranium tailings presented a tendency to transform from the acid-soluble state to residual state. In addition, the introduction of exogenous SRB-PSB can significantly increase the richness and diversity of endogenous microorganisms, effectively maintain the reductive environment for the microbial stabilization system, and promote the growth of functional microorganisms, such as sulfate-reducing bacteria ( and ) and iron-reducing bacteria ( and ). Finally, PCoA and CCA analyses showed that temperature and inoculation volume had significant effects on microbial community structure, and the influence order of the three environmental factors is as follows: inoculation volume > temperature > pH. The outcomes of this study provide theoretical support for the control of uranium in uranium-contaminated sites.
尾矿中的铀污染及其衰变产物是一个全球性的环境问题。采用经济高效的技术修复铀污染土壤具有重要意义。本研究通过混合硫酸盐还原菌（SRB）和溶磷菌（PSB，菌株grinm - 12）在修复过程中的单因素批次实验，研究了pH、温度和接种量对铀尾矿稳定化效率和微生物群落响应的影响。结果表明，混合SRB - PSB微生物稳定化的最佳参数为pH 5.0、温度25℃和接种量10%。在最佳条件下，铀尾矿中的铀呈现出从酸溶态向残渣态转化的趋势。此外，引入外源SRB - PSB可显著增加内源微生物的丰富度和多样性，有效维持微生物稳定化系统的还原环境，并促进硫酸盐还原菌（和）及铁还原菌（和）等功能微生物的生长。最后，主坐标分析（PCoA）和典范对应分析（CCA）表明，温度和接种量对微生物群落结构有显著影响，三个环境因素的影响顺序为：接种量＞温度＞pH。本研究结果为铀污染场地中铀的控制提供了理论支持。
