School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China.
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, People's Republic of China; Xi'an Municipal Design and Research Institute, No.100 Zhuque Road, Xi'an 710068, People's Republic of China.
Sci Total Environ. 2022 Feb 20;808:152203. doi: 10.1016/j.scitotenv.2021.152203. Epub 2021 Dec 7.
Traditional air or oxygen injection is an effective and economical mitigation strategy for sulfide control in pressure sewers, but it is not suitable for gravity sewers due to the low solubility of oxygen in water under normal atmospheric conditions. Herein, an air-nanobubble (ANB) injection method was proposed for sulfide mitigation in gravity sewers, and its sulfide control efficiency was evaluated by long-term laboratory gravity sewer reactors. The results showed that an average inhibition rate of 45.36% for sulfide was obtained when ANBs were implemented, which was 3.75 times higher than that of the traditional air injection method, revealing the effectiveness and feasibility of the ANB injection method. As suggested by microbial community analysis of sewer biofilms, the relative abundance of sulfate-reducing bacteria (SRB) decreased 40.57% while that of sulfur oxidizing bacteria (SOB) increased 215.27% in the presence of ANBs, indicating that sulfide mitigation by ANB injection included both the inhibition of sulfide production and the oxidation of dissolved sulfide. The specific cost consumption of ANB injection was 1.7 $/kg-S, which was only 6.85% of that of traditional air injection (24.8 $/kg-S), suggesting that the sustainable supply of oxygen based on ANB injection is not only environmentally but also economically beneficial for sulfide mitigation. The findings of this study may provide an efficient sulfide mitigation strategy for the management of corrosion and malodour issues in the poorly ventilated gravity sewers.
传统的空气或氧气注入是控制压力污水中硫化物的有效且经济的缓解策略，但由于在正常大气条件下氧气在水中的溶解度低，因此不适合重力污水。本文提出了一种用于重力污水中硫化物缓解的空气纳米气泡（ANB）注入方法，并通过长期实验室重力污水反应器评估了其硫化物控制效率。结果表明，实施 ANB 时，硫化物的平均抑制率达到 45.36%，是传统空气注入方法的 3.75 倍，表明 ANB 注入方法的有效性和可行性。根据污水生物膜的微生物群落分析，ANB 的存在使硫酸盐还原菌（SRB）的相对丰度降低了 40.57%，而硫氧化菌（SOB）的相对丰度增加了 215.27%，表明 ANB 注入的硫化物缓解包括抑制硫化物的产生和溶解硫化物的氧化。ANB 注入的特定成本消耗为 1.7 美元/千克-S，仅为传统空气注入（24.8 美元/千克-S）的 6.85%，这表明基于 ANB 注入的可持续氧气供应不仅在环境方面，而且在经济方面都有利于硫化物缓解。本研究的结果可为管理通风不良的重力污水中腐蚀和恶臭问题提供一种有效的硫化物缓解策略。
