零价铁联合微生物去除水中高氯酸盐的研究

本研究通过监测一系列续批实验中高氯酸根(ClO-4)质量浓度随时间的变化情况,研究了Fe0投加量、微生物加入量、ClO-4负荷、初始pH等因素对微生物利用零价铁(Fe0)做电子供体去除水中ClO-4的影响。结果表明与以前的研究不同,Fe0投加量并非越多越好,当初始ClO-4质量浓度为10000μg／L时,Fe0投加量(质量浓度)选择40g／L较为合适,既可以保证充足的电子供应又不会因为大量铁腐蚀引起体系pH过快升高;自行驯化的高氯酸盐降解微生物(perchlorate reducing microbes, PRMs)对ClO-4的去除负荷为603μg／(L?hr?gPRMs),完全可以取代纯种微生物应用于环境水体中ClO-4的去除;所用PRMs 的最适pH条件为7.0,其对初始pH更为敏感而对反应进行中pH的变化有较大承受范围;另外通过建立微生物种群的系统发育树发现PRMs 的种群结构在实验过程中发生了部分变化。本研究在一定程度上为Fe0联合微生物去除ClO-4技术的推广应用提供了理论支撑。

Perchlorate removal in water by bacteria associated with Fe0

According to the variation of perchlorate mass concentration as a function of time in a series of batch tests, the influence on perchlorate removal by perchlorate reducing microbes (PRMs) associated with Fe0 as electron donor was investigated, which was caused by some relative factors, such as Fe0 adding amount, bacteria concentration, perchlorate load, and initial pH. The results showed that unlike some research before, the Fe0 adding amount was not as much as better. The optimum Fe0 adding amount (mass concentration) with perchlorate mass concentration at 10000 μg／L was about 40g／L. In this case, enough electrons could be produced, while the pH increased not too fast. The perchlorate load for PRMs used in this research was about 603μg／(L?hr?gPRMs), which could take the place of pure microbes to undertake perchlorate removal in the environmental water. The optimum pH for PRMs was around 7.0. The PRMs were more sensitive to the variation of initial pH, but they could survive in a wider range of pH during the reaction. In addition, the changes of the main PRMs species were analyzed through building phylogenetic tree. Compared with the microbes after incubation, the bacteria species partly changed after the experiments. This research may provide a theoretical support for the application of perchlorate removal by PRMs associated with Fe0 to a certain degree.