Zhang Yuanyuan, Liu Shuang, Zhang Gaorong, Peng Yixiang, Wei Qiaoyan, Jiang Minmin, Zheng Junjian
College of Life and Environmental Science, Guilin University of Electronic Technology, Guilin, China.
Guangxi Key Laboratory of Automatic Detecting Technology and Instruments, Guilin University of Electronic Technology, Guilin, China.
Front Bioeng Biotechnol. 2023 Mar 10;11:1133613. doi: 10.3389/fbioe.2023.1133613. eCollection 2023.
Current microbial reduction technologies have been proven to be suitable for decontaminating industrial wastewaters containing high concentrations of selenium (Se) oxyanions, however, their application is strictly limited by the elemental Se (Se) accumulation in the system effluents. In this work, a continuous-flow anaerobic membrane bioreactor (AnMBR) was employed for the first time to treat synthetic wastewater containing 0.2 mM soluble selenite (SeO ). The SeO removal efficiency by the AnMBR was approachable to 100% in most of the time, regardless of the fluctuation in influent salinity and sulfate (SO ) stress. Se particles were always undetectable in the system effluents, owing to their interception by the surface micropores and adhering cake layer of membranes. High salt stress led to the aggravated membrane fouling and diminished content ratio of protein to polysaccharide in the cake layer-contained microbial products. The results of physicochemical characterization suggested that the sludge-attached Se particles presented either sphere- or rod-like morphology, hexagonal crystalline structure and were entrapped by the organic capping layer. According to the microbial community analysis, increasing influent salinity led to the diminished population of non-halotolerant Se-reducer () and increased abundance of halotolerant sulfate reducing bacteria (). In the absence of , the efficient SeO abatement performance of the system could still be maintained, as a result of the abiotic reaction between SeO and S generated by , which then gave rise to the production of Se and S.
目前的微生物还原技术已被证明适用于对含有高浓度硒（Se）含氧阴离子的工业废水进行去污处理，然而，其应用受到系统流出物中元素硒（Se）积累的严格限制。在本研究中，首次采用连续流厌氧膜生物反应器（AnMBR）处理含有0.2 mM可溶性亚硒酸盐（SeO ）的合成废水。在大多数情况下，AnMBR对SeO 的去除效率接近100%，不受进水盐度波动和硫酸盐（SO ）胁迫的影响。由于系统流出物中的Se颗粒被膜表面微孔和附着的滤饼层截留，因此在系统流出物中始终检测不到Se颗粒。高盐胁迫导致膜污染加剧，且滤饼层中含有的微生物产物中蛋白质与多糖的含量比降低。物理化学表征结果表明，污泥附着的Se颗粒呈现球形或棒状形态、六方晶体结构，并被有机覆盖层包裹。根据微生物群落分析，进水盐度增加导致非耐盐性Se还原菌（）数量减少，耐盐性硫酸盐还原菌（）丰度增加。在没有 的情况下，由于SeO 与 产生的S之间的非生物反应，系统仍可保持高效的SeO 去除性能，进而产生Se和S。
