State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
J Hazard Mater. 2017 Apr 5;327:89-96. doi: 10.1016/j.jhazmat.2016.12.028. Epub 2016 Dec 19.
Five lab-scale membrane bioreactors (MBRs) were continuously operated to investigate the mechanisms and linkages of the microbial community and membrane fouling with trivalent metal cations (Fe(III) and Al(III)) and bivalent metal cations (Ca(II) and Mg(II)) shock loads. COD and NH-N removals showed recovery trends along with treatment process in the presence of metals. Trivalent metal cations reduced trans-membrane pressure (TMP) as well as fouling rate (dTMP/dt) and extended membrane module replacement period by binding activated sludge extracellular polymeric substance (EPS) and effluent soluble microbial product (SMP) productions. Illunima sequencing of 16S rRNA gene showed that metal stress stimulated specific metal-tolerance bacteria in the MBRs. Canonical correspondence analysis indicated that EPS and SMP made different contributions to the distribution of microbial community structure in Fe(III) and Al (III) systems, respectively. Under bivalent metal conditions, microbial community shifts and Ca(II) binding bridge worked together to inhibit EPS and SMP, while filamentous bacteria stimulated by Mg(II) that mainly controlled membrane fouling. This study has shown that the comparison of tri- and bivalent metals for membrane fouling control with binding bridge and functional microorganisms can provide a strategy for practical membrane bioreactor applications.
连续运行了五个实验室规模的膜生物反应器（MBR），以研究微生物群落与膜污染与三价金属阳离子（Fe(III)和 Al(III)）和二价金属阳离子（Ca(II)和 Mg(II)）冲击负荷之间的机制和联系。在金属存在的情况下，COD 和 NH-N 的去除率表现出随着处理过程的恢复趋势。三价金属阳离子通过结合活性污泥胞外聚合物（EPS）和出水可溶性微生物产物（SMP）的产生，降低了跨膜压力（TMP）以及污染速率（dTMP/dt），并延长了膜组件更换周期。16S rRNA 基因的 Illumina 测序表明，金属胁迫刺激了 MBR 中的特定金属耐受细菌。典范对应分析表明，EPS 和 SMP 分别对 Fe(III)和 Al(III)系统中微生物群落结构的分布有不同的贡献。在二价金属条件下，微生物群落的变化和 Ca(II)结合桥共同抑制 EPS 和 SMP，而受 Mg(II)刺激的丝状菌则主要控制膜污染。本研究表明，比较三价和二价金属对具有结合桥和功能微生物的膜污染控制，可以为实际膜生物反应器应用提供一种策略。
