School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou, PR China.
College of Science and Engineering, Hamad Bin Khalifa University, Education City, Doha, Qatar.
Water Res. 2018 Apr 15;133:165-172. doi: 10.1016/j.watres.2018.01.022. Epub 2018 Jan 19.
Autotrophic denitrification has been widely studied for odor mitigation, corrosion control and nitrogen removal in recent years. This paper examines the response of sulfur-oxidizing bacteria (SOB) driven autotrophic denitrification under short-term stress of dissolved sulfide. A series of batch tests were conducted to investigate the effect of different sulfide concentrations (0-1600 mg-total dissolved sulfide (TDS)/L) on autotrophic denitrification and sulfide oxidation by SOB-enriched sludge. Our results show that autotrophic denitrification (NO to N) was stimulated up to 200 mg-TDS/L with a maximum denitrification rate of 9.4 mg-N/g-volatile suspended solids (VSS)/h, and the nitrite reduction was a rate limiting step. When sulfide concentration was higher than 200 mg-TDS/L, it inhibited nitrate reductase, and nitrate reduction became the rate limiting step according to Edwards and Aiba inhibition models. Sulfide oxidation, however, was not inhibited and the maximum rate of 100.3 mg-TDS/g-VSS/h was obtained at sulfide concentration of 1000 mg-TDS/L. It is important to point out that the transient inhibition on autotrophic denitrification caused by high sulfide stress was resilient and non-lethal with no significant changes in cell viability even under sulfide concentration of 1000 mg-TDS/L. This study reveals the stimulatory and inhibitory effects of dissolved sulfide on SOB driven autotrophic denitrification and its possible underlying mechanism with discussion on engineering implications.
近年来，自养反硝化因其在恶臭缓解、腐蚀控制和脱氮方面的应用而受到广泛研究。本文考察了硫氧化菌（SOB）驱动的自养反硝化在溶解态硫化物短期胁迫下的响应。进行了一系列批式试验，以研究不同硫化物浓度（0-1600mg 总溶解态硫化物（TDS）/L）对富硫氧化菌（SOB）污泥的自养反硝化和硫化物氧化的影响。结果表明，自养反硝化（NO 到 N）在 200mg-TDS/L 以下受到刺激，最大反硝化速率为 9.4mg-N/g 挥发性悬浮固体（VSS）/h，亚硝酸盐还原为限速步骤。当硫化物浓度高于 200mg-TDS/L 时，它抑制硝酸还原酶，根据 Edwards 和 Aiba 抑制模型，硝酸盐还原成为限速步骤。然而，硫化物氧化并未受到抑制，在 1000mg-TDS/L 的硫化物浓度下获得了 100.3mg-TDS/g-VSS/h 的最大速率。需要指出的是，高硫化物胁迫下对自养反硝化的短暂抑制是有弹性的，非致死性的，即使在 1000mg-TDS/L 的硫化物浓度下，细胞活力也没有明显变化。本研究揭示了溶解态硫化物对 SOB 驱动的自养反硝化的刺激和抑制作用及其可能的潜在机制，并讨论了其工程意义。
