State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Advanced Water Management Centre, The University of Queensland, St Lucia, QLD 4072, Australia.
Environ Int. 2020 Oct;143:105928. doi: 10.1016/j.envint.2020.105928. Epub 2020 Jul 13.
Emissions of hydrogen sulfide and methane are two of the major concerns in sewers, causing corrosion, odour and health problems. This study proposed a new free ammonia (FA)-based approach for controlling the biological production of sulfide and methane in sewers. This is based on the discovery that the FA contained in urine wastewater is strongly biocidal to anaerobic sewer biofilms. Long-term operation of two laboratory sewer reactors, with one being dosed with urine wastewater and the other being dosed with raw sewage as a control, revealed the effectiveness of the proposed FA approach. The results showed that dosing of real urine wastewater at FA concentration of 154 mg NH-N/L with exposure for 24 h immediately reduced over 80% sulfide and methane in the experimental sewer reactor, while the time for recovering 50% sulfide and methane production were 6 days and 28 days, respectively. It also showed that intermittent dosing with an interval time of 5-15 days reduced around 60% sulfide on average. As suggested by community analysis, the remaining sulfide might be produced by a sulfate-reducing bacterial genus Desulfobulbus. Collectively, urine is a part of municipal sewage, and thus separation and re-dosing of the urine wastewater into the sewer for sulfide and methane control should enable the minimization of operational costs and environmental impacts, compared with the previous dosing of chemicals.
硫化氢和甲烷的排放是污水中主要关注的问题之一，会导致腐蚀、恶臭和健康问题。本研究提出了一种新的基于游离氨（FA）的方法来控制污水中硫化物和甲烷的生物生成。这是基于发现尿液废水中含有的 FA 对厌氧污水生物膜具有很强的杀菌作用。通过长期运行两个实验室污水反应器，一个用尿液废水进行处理，另一个用原污水作为对照，验证了所提出的 FA 方法的有效性。结果表明，用 FA 浓度为 154mgNH-N/L 的实际尿液废水进行处理，暴露 24 小时后，实验污水中的硫化物和甲烷立即减少了 80%以上，而恢复 50%硫化物和甲烷生成所需的时间分别为 6 天和 28 天。结果还表明，每隔 5-15 天进行间歇性处理，平均可减少约 60%的硫化物。根据群落分析的结果，剩余的硫化物可能是由硫酸盐还原菌属 Desulfobulbus 产生的。总的来说，尿液是城市污水的一部分，因此将尿液废水分离并重新注入污水中以控制硫化物和甲烷的排放，与之前投加化学药剂相比，可以最大限度地降低运营成本和环境影响。
