Institute of Environmental Research, Kangwon National University, 1 Gangwondaehak-gil, Chuncheon-si, Gangwon-do 24341, Republic of Korea.
Department of Civil and Environmental Engineering, Pusan National University, 63 Busandeahak-ro, Geumjeong-Gu, Busan 46241, Republic of Korea.
Sci Total Environ. 2021 Mar 1;758:143592. doi: 10.1016/j.scitotenv.2020.143592. Epub 2020 Nov 17.
Despite increasing interests in osmotic membrane bioreactors, the information regarding the bacterial toxicity effects of reversely transported draw solute (RTDS) is limited. In this study, two representative draw solutes (NaCl and MgCl) were used at different concentrations (0, 2.5, 5.0, 7.5 and 10.0 g/L) to evaluate their toxicity in a continuous nitrifying bioreactor. Notably, Mg selectively inhibited the activity of ammonia-oxidizing bacteria (AOB), which decreased to 11.3% at 7.5 g-Mg/L. The rRNA-based analysis was more effective than the rDNA-based analysis to elucidate the relationship between active communities of nitrifying bacteria and the actual nitrifying performance. Nitrosomonas europaea, a representative AOB, was vulnerable to Mg in comparison to Na. In contrast, the dominant nitrite-oxidizing bacteria (NOB), Nitrobacter winogradskyi and Nitrolancea hollandica, maintained a relevant level of relative abundance for achieving nitrite oxidation after exposure to 10 g/L Na and Mg. This fundamental inhibition information of the draw solute can be applied to set the operational regime preventing the critical solute concentration in mixed liquor of nitrifying OMBRs.
尽管人们对渗透膜生物反应器越来越感兴趣，但关于反向传输的汲取剂（RTDS）对细菌毒性影响的信息有限。在这项研究中，使用了两种代表性的汲取剂（NaCl 和 MgCl），浓度分别为 0、2.5、5.0、7.5 和 10.0 g/L，以评估它们在连续硝化生物反应器中的毒性。值得注意的是，Mg 选择性地抑制了氨氧化菌（AOB）的活性，当浓度为 7.5 g-Mg/L 时，AOB 的活性下降到 11.3%。基于 rRNA 的分析比基于 rDNA 的分析更有效地阐明了硝化细菌活性群落与实际硝化性能之间的关系。与 Na 相比，硝化单胞菌（Nitrosomonas europaea）等代表性 AOB 对 Mg 更为敏感。相比之下，亚硝酸盐氧化菌（NOB），如硝化杆菌（Nitrobacter winogradskyi）和荷兰亚硝化球菌（Nitrolancea hollandica），在暴露于 10 g/L Na 和 Mg 后，仍能保持相对丰富度，从而实现亚硝酸盐氧化。这种汲取剂的基本抑制信息可应用于设置操作模式，以防止硝化 OMBR 混合液中汲取剂的临界浓度。
