The water-energy nexus plays a significant role on society and on the industrial panorama. Creating a network of self-powered smart sensors for quality evaluation on wastewater treatment stations would allow for major automation of this process while decreasing its energy dependence. Current technology allows energy harvesting from wastewater with Microbial Fuel Cells. This work reports on the construction and evaluation of a single-chamber air-cathode microbial fuel cell for power production. Around 900 mW.m^-2 of power was retrieved from this source and used on a low power energy harvesting kit after leveled up on a voltage booster. The sensing system is developed around a low power microcontroller.