Nitrate effects on chromate reduction in a methane-based biofilm.
Nitrate effects on chromate reduction in a methane-based biofilm.
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DOI：
10.1016/j.watres.2017.03.003
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发表时间：
2017-05
期刊：
影响因子：
12.8
通讯作者：
Liang Zhong;Chun-Yu Lai;Ling-Dong Shi;Kai-Di Wang;Yunrong Dai;Yaowei Liu;F. Ma;B. Rittmann
中科院分区：
文献类型：
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作者：
Liang Zhong;Chun-Yu Lai;Ling-Dong Shi;Kai-Di Wang;Yunrong Dai;Yaowei Liu;F. Ma;B. Rittmann
在膜生物膜反应器（MBfR）中，以CH 4为唯一电子供体，研究了NO3-对Cr（VI）还原的影响.高表面负载的NO3−对Cr（VI）还原产生显著且不可逆的抑制作用。在500 mg Cr/m2-d的表面负荷下，当不存在NO3−时（第1阶段），Cr（VI）去除率为100%，但当引入280 mg N m−2-d NO3−时（第2阶段），Cr（VI）去除率急剧下降至< 25%。在第2阶段运行约50天后，Cr（VI）的去除率在第3阶段仅恢复到约70%，当NO3-从进水中去除时，因此NO3-对Cr（VI）的去除具有显著的长期抑制作用。加权PCoA和UniFrac分析证明，NO3−的引入对生物膜中的微生物群落产生了强烈的影响，这种变化可能与Cr（VI）还原的不可逆抑制有关。例如，Meiothermus，最初参与Cr（VI）还原的主要属，随着NO3−的引入而下降。加入NO3-后，降解菌Chitinophagaceae富集，而去除硝酸盐后，Pelomonas变得重要，表明其可能作为Cr（VI）还原剂。此外，引入NO3−导致预测（PICRUSt）与铬酸盐还原相关的基因数量减少，但预测与反硝化，甲烷氧化和发酵相关的基因增加。
The effects of nitrate (NO3−) on chromate (Cr(VI)) reduction in a membrane biofilm reactor (MBfR) were studied when CH4was the sole electron donor supplied with a non-limiting delivery capacity. A high surface loading of NO3−gave significant and irreversible inhibition of Cr(VI) reduction. At a surface loading of 500 mg Cr/m2-d, the Cr(VI)-removal percentage was 100% when NO3−was absent (Stage 1), but was dramatically lowered to < 25% with introduction of 280 mg N m−2-d NO3−(Stage 2). After ∼50 days operation in Stage 2, the Cr(VI) reduction recovered to only ∼70% in Stage 3, when NO3−was removed from the influent; thus, NO3−had a significant long-term inhibition effect on Cr(VI) reduction. Weighted PCoA and UniFrac analyses proved that the introduction of NO3−had a strong impact on the microbial community in the biofilms, and the changes possibly were linked to the irreversible inhibition of Cr(VI) reduction. For example,Meiothermus, the main genus involved in Cr(VI) reduction at first, declined with introduction of NO3−. The denitrifierChitinophagaceaewas enriched after the addition of NO3−, whilePelomonasbecame important when nitrate was removed, suggesting its potential role as a Cr(VI) reducer. Moreover, introducing NO3−led to a decrease in the number of genes predicted (by PICRUSt) to be related to chromate reduction, but genes predicted to be related to denitrification, methane oxidation, and fermentation increased.