The corrosion of concrete sewer infrastructure is a common problem that affects water utilities worldwide. It causes the loss of concrete mass in the sewer, causing cracking and eventually pipe collapse. This causes the need for significant amounts of money to be spent by these utilities on sewer maintenance rehabilitation and chemical costs to manage this issue.

Concrete corrosion results from two key processes: firstly, the microbial reduction of sulfates to hydrogen sulfide and secondly, the microbial oxidation of the hydrogen sulfide to sulfuric acid. It is the sulfuric acid that is responsible for the majority of the concrete corrosion, weakening the overall sewer infrastructure. The production of hydrogen sulfide also presents both environmental and safety implications due to its strong odour and toxicity in high concentrations. 

Electromicrobiology studies the ability of electric microbes (electricigens), which are ubiquitous in wastewater, to directly transfer electrons to and from electrodes. To address the issue of the corrosion of sewer infrastructure, we aim to exploit the ability of electricigens to utilise an electrode reducing the production of hydrogen sulfide and sulfuric acid within the microbial community. If successful, this application has the potential to save water utilities large amounts in operating expenditure, resulting in cheaper services for customers.

Since the microbial communities present in the sewer drive the corrosion cycle it is paramount to understand both their structure and function. If the sulfur cycling occurring within these communities can be disrupted, then the formation of sulfuric acid and consequently the corrosion of sewer infrastructure can be stopped. This is where the use of electromicrobiology can aid us in finding a potential solution to this widespread problem.