Effect of H2S on N2O Reduction and Accumulation during Denitrification by Methanol Utilizing Denitrifiers
Effect of H2S on N2O Reduction and Accumulation during Denitrification by Methanol Utilizing Denitrifiers
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DOI：
10.1021/es401632r
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发表时间：
2013-08-06
影响因子：
11.4
通讯作者：
Yuan, Zhiguo
中科院分区：
文献类型：
--
作者：
Pan, Yuting;Ye, Liu;Yuan, Zhiguo
污水管网中会产生硫化物，以往的研究表明，污水中的硫化物会改变污水生物处理过程中异养反硝化的活性，导致N2 O的积累。然而，人们对这一现象的细节知之甚少。在这项研究中，潜在的抑制作用的硫化物硝酸盐，亚硝酸盐，和N2 O还原与甲醇利用的反硝化培养之前和之后的暴露和适应硫化物进行了评估。硫化氢被发现是强烈抑制N2 O还原，与50%的抑制观察到的H2S浓度为0.04毫克H2S-S/L和0.1毫克H2S-S/L的未适应和适应的文化，分别。相比之下，硝酸盐和亚硝酸盐还原更耐受H2S。对于未适应和适应的培养物，在约2.0 mg H2S-S/L下观察到对亚硝酸盐还原的50%抑制，而在向任一培养物施加的最高H2S浓度（2.0 mg H2S-S/L）下未发生对硝酸盐还原的抑制。当（HS）-S-2浓度分别大于0.5和0.2 mg H2S-S/L时，在硝酸盐还原和亚硝酸盐还原过程中均观察到N2 O积累。此外，我们发现，硫化氢（H2S），而不是硫化物，可能是真正的抑制剂N2 O还原，抑制作用是可逆的。这些研究结果表明，硫化物管理下水道可能会产生显着的影响，从污水处理厂的N2 O排放。
Sulfide is produced in sewer networks, and previous studies suggest that sulfide in sewage could alter the activity of heterotrophic denitrification and lead to N2O accumulation during biological wastewater treatment. However, the details of this phenomenon are poorly understood. In this study, the potential inhibitory effects of sulfide on nitrate, nitrite, and N2O reduction were assessed with a methanol-utilizing denitrifying culture both prior to and after its exposure and adaptation to sulfide. Hydrogen sulfide was found to be strongly inhibitory to N2O reduction, with 50% inhibition observed at H2S concentrations of 0.04 mg H2S-S/L and 0.1 mg H2S-S/L for the unadapted and adapted cultures, respectively. In comparison, both nitrate and nitrite reduction was more tolerant to H2S. A 50% inhibition of nitrite reduction was observed at approximately 2.0 mg H2S-S/L for both unadapted and adapted cultures, while no inhibition of nitrate reduction occurred at the highest H2S concentrations applied (2.0 mg H2S-S/L) to either culture. N2O accumulation was observed during nitrate and nitrite reduction by the adapted culture when (HS)-S-2 concentrations were above 0.5 and 0.2 mg H2S-S/L, respectively. Additionally, we reveal that hydrogen sulfide (H2S), rather than sulfide, was likely the true inhibitor of N2O reduction, and the inhibitory effect was reversible. These findings suggest that sulfide management in sewers could potentially have a significant impact on N2O emission from wastewater treatment plants.