Finding low-cost ways to engineeranaerobic communities,to enhance the operation of rural septic tanks

In remote, rural or areas all over the world, septic tanks are the most prevalent to treat domestic waste water before disposal into the environment. Septic tanks, are underground chambers made of concrete in which, providing an anaerobic environment, microbial communities grow degrading the organic matter present in the wastewater. This removes the contaminants in the water, and this can be released into the environment. Currently, the engineering of these systems is very poor which implies that their operation is always subjected to failure, and their efficiency is low. This increases the risks of environmental contamination of ground water which, in some cases, could have an effect in surface waters affecting supplies of drinking water. In this project, I propose to explore the optimization of these septic tanks analysing the microbial community present in the system to find novel ways to engineer it. The microbial communities that grow in the septic tank, are characterised by the presence of several populations that form metabolic synergies between them. Environmental conditions and the chemical characteristics of the wastewater, change the structure of these communities and in some cases, provoke the failure of the process. Increasing the diversity and robustness of the microbial culture might lead to a more efficient and reliable process. To achieve this, I am going to develop state-of-the-art mathematical models able to describe microbial activity under anaerobic conditions. These will allow us to analyse the synergies stablished between the different populations in the system. The mathematical description will allow me to connect microbial activity and the environmental conditions imposed and, therefore, this project will aim to propose novel designs to enhance the biological activity and overall, the performance of the system. For example, one hypothesis is that microbial diversity might increase the robustness of the operation of septic tanks. If I am able to predict in-silico which conditions will increase diversity of the anaerobic microbial community, this will lead the proposal of a novel engineered system less subject to failure than the actual systems.