State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
Chemosphere. 2021 Oct;280:130937. doi: 10.1016/j.chemosphere.2021.130937. Epub 2021 May 19.
Nitrate and sulfate often coexist in organic wastewater. In this study, an internal circulation anaerobic reactor was conducted to investigate the impact of nitrate on sulfate reduction. The results showed that sulfate reduction rate dropped from 78.4% to 41.4% at NO /SO ratios ranging from 0 to 1.03, largely attributed to the inactivity of acetate-utilizing sulfate-reducing bacteria (SRB) and preferential usage of nitrate of propionate-utilizing SRB. Meanwhile, high nitrate removal efficiency was maintained and COD removal efficiency increased with nitrate addition. Enhancement of propionate and butyrate degradation based on Modified Gompertz model and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) analysis. Moreover, nitrate triggered the shift of microbial community and function. Twelve genera affiliated to Firmicutes, Bacteroidetes and Proteobacteria were identified as keystone genera via network analysis, which kept functional stability of the bacterial community responding to nitrate stress. Increased nitrate inhibited Desulfovibrio, but promoted the growth of Desulforhabdus. Both the predicted functional genes associated with assimilatory sulfate reduction pathway (cysC and cysNC) and dissimilatory sulfate reduction pathway (aprA, aprB, dsrA and dsrB) exhibited negative relationship with nitrate addition.
硝酸盐和硫酸盐通常共存于有机废水中。在本研究中，采用内循环厌氧反应器研究了硝酸盐对硫酸盐还原的影响。结果表明，当 NO /SO 比从 0 增加到 1.03 时，硫酸盐还原率从 78.4%下降到 41.4%，这主要归因于乙酸盐利用硫酸盐还原菌（SRB）的失活和丙酸盐利用 SRB 对硝酸盐的优先利用。同时，随着硝酸盐的添加，保持了较高的硝酸盐去除效率，COD 去除效率也有所提高。基于修正的 Gompertz 模型和未观测状态重构的群落系统发育分析（PICRUSt2）分析，增强了丙酸和丁酸的降解。此外，硝酸盐引发了微生物群落和功能的转变。通过网络分析，确定了 12 个与厚壁菌门、拟杆菌门和变形菌门相关的属为关键属，这些属保持了细菌群落对硝酸盐胁迫的功能稳定性。增加的硝酸盐抑制了脱硫弧菌，但促进了脱硫脱硫肠状菌的生长。与同化硫酸盐还原途径（cysC 和 cysNC）和异化硫酸盐还原途径（aprA、aprB、dsrA 和 dsrB）相关的预测功能基因均与硝酸盐添加呈负相关。
