Microbial community response to corrosion dosing treatments in sewer

Background: Odorous H2S emissions have long been a problem for water industries. They can impact community health and are a critical component in microbially induced concrete corrosion (MICC) of the sewers. MICC leads to concrete deterioration resulting in a significantly reduced lifespan of sewer pipes. If left untreated, MICC can result in catastrophic failure and collapse of sewer infrastructure.Methods: This project explores the efficiency of three liquid dosing treatments: one chemical (magnesium hydroxide) and two biological treatments (Bioproduct A and B); proposed to reduce H2S emissions within the sewer system. Four dosing trials were run over the course of a year: two dosing magnesium hydroxide and one for Bioproduct A and Bioproduct B respectively. These trials were run on two lines of an operational sewer, each line comprising of a high H2S emitting site where the treatment was dosed and a low H2S emitting site utilised as a comparative control. H2S emissions and microbial community samples were analysed to understand the effectiveness of these treatments on reducing H2S emissions and their impact on microbial community structure. The effect of high rainfall on H2S emissions and the composition of tidal biofilm communities was also investigated.

背景：恶臭硫化氢（H₂S）排放长期以来都是水务行业面临的难题。该排放物不仅会威胁社区公众健康，同时也是引发市政下水道微生物诱导混凝土腐蚀（microbially induced concrete corrosion, MICC）的关键诱因。微生物诱导混凝土腐蚀会导致混凝土劣化，显著缩短市政管道的使用寿命；若未及时处理，该腐蚀问题可引发下水道基础设施发生灾难性失效乃至整体坍塌。方法：本项目针对三种液体投加处理工艺的减排效果展开研究，分别为1种化学药剂（氢氧化镁）与2种生物制剂（Bioproduct A、Bioproduct B），旨在降低市政下水道系统内的硫化氢排放。本次研究共开展四组为期一年的投加试验：两组采用氢氧化镁投加，剩余两组分别采用Bioproduct A与Bioproduct B。试验在两条正在运营的市政下水道管线上进行，每条管线均设置一处实施投加处理的高硫化氢排放点位，以及一处作为对照的低硫化氢排放点位。研究人员通过分析硫化氢排放数据与微生物群落样本，明确上述处理工艺对硫化氢减排的效果，及其对微生物群落结构的影响；同时还探究了强降雨对硫化氢排放以及潮汐性生物膜群落组成的影响。