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.