Abstract The effects of water permeation intensity on nitrifying bacterial activity, forward osmosis (FO) membrane performance, and bacterial community structure were investigated in an osmotic membrane bioreactor (OMBR). Ammonia was partially oxidized by controlling acidification buffer concentration. Then, the FO module was externally integrated with a nitrifying bioreactor to examine nitrifying bacterial activity in response to the increased salinity. The salinity gradually increased from 2.7 to 45.7 g.L−1 total dissolved solids (TDS). Inhibition of nitrite-oxidizing activity was initiated at a salt concentration of 36.2 g.L−1 TDS. Complete ammonia-oxidizing bacteria inhibition occurred at 45.7 g.L−1 TDS. Illumina high-throughput sequencing revealed that the bacterial community responded to the operational conditions such as the ammonia loading rate and salt concentration. Only two species, Nitrosomonas eutropha and Nitrobacter winogradskyi, were responsible for nitrification in the OMBR. The cellulose triacetate FO membrane showed poor rejection efficiencies for ammonia, nitrite, and nitrate. The FO module was capable to maximally recover 107.8% water in the OMBR. However, the water permeation intensity should be appropriately adjusted to avoid nitrification failure by maintaining the optimal salinity as lower than 35 g.L−1 TDS, which is equivalent to water permeation efficiency of 107.8% in this study.

中文翻译：

---

渗透膜生物反应器不同透水强度下硝化稳定性及膜性能

摘要 在渗透膜生物反应器 (OMBR) 中研究了水渗透强度对硝化细菌活性、正渗透 (FO) 膜性能和细菌群落结构的影响。通过控制酸化缓冲液浓度，氨被部分氧化。然后，FO 模块与硝化生物反应器外部集成，以检查硝化细菌对盐度增加的反应。总溶解固体 (TDS) 的盐度从 2.7 逐渐增加到 45.7 gL-1。亚硝酸盐氧化活性的抑制始于 36.2 gL-1 TDS 的盐浓度。在 45.7 gL-1 TDS 时发生完全的氨氧化细菌抑制。Illumina高通量测序显示细菌群落对氨负载率和盐浓度等操作条件做出反应。只有两个物种，亚硝化单胞菌 eutropha 和 Nitrobacter winogradskyi，负责 OMBR 中的硝化作用。三醋酸纤维素 FO 膜对氨、亚硝酸盐和硝酸盐的截留率很低。FO 模块能够最大程度地回收 OMBR 中 107.8% 的水。然而，应适当调整水渗透强度以避免硝化失败，将最佳盐度保持在低于 35 gL-1 TDS，相当于本研究中水渗透效率为 107.8%。三醋酸纤维素 FO 膜对氨、亚硝酸盐和硝酸盐的截留率很低。FO 模块能够最大程度地回收 OMBR 中 107.8% 的水。然而，应适当调整水渗透强度，通过保持最佳盐度低于 35 gL-1 TDS 来避免硝化失败，这相当于本研究中 107.8% 的水渗透效率。三醋酸纤维素 FO 膜对氨、亚硝酸盐和硝酸盐的截留率很低。FO 模块能够最大程度地回收 OMBR 中 107.8% 的水。然而，应适当调整水渗透强度以避免硝化失败，将最佳盐度保持在低于 35 gL-1 TDS，相当于本研究中水渗透效率为 107.8%。