Miniature microbial fuel cells integrated with triggered power management systems to power wastewater sensors in an uninterrupted mode

Uninterrupted energy harvest is critical for self-sustained wastewater monitoring in order to achieve efficient and resilient operation of decentralized onsite wastewater treatment facilities. To address this long-standing challenge, an integrated power entity consisting of a miniature microbial fuel cell (volume: 1.5 mL) and a triggered power management system was developed in this study to power the potentiometric millimeter-sized solid-state water sensors for real-time in situ monitoring and uninterrupted transmission of sensor readings (indicating ammonium concentration) under both ammonium shock and toxic shock in wastewater. Specifically, a data trigger including two capacitors, an operation amplifier and a low-power comparator is equipped in the power management system as a switch for turning on power discharge for data transmission once the ammonium shock is captured by the potentiometric sensors, enabling a sufficient recharge duration to store the power needed for high frequency data transmission (16.23 times/min) required under shocks. Furthermore, this power-sensor entity possesses a unique dual-screening capability of capturing the ammonium and toxic shocks, providing an early warning for swift decision making, reducing-17% of ammonium discharge and saving-42% of energy consumption in decentralized onsite wastewater treatment facilities.

Automated summary

In order to achieve efficient operation of wastewater treatment facilities, this study developed an integrated power entity to power water sensors for real-time and continuous monitoring of wastewater, reducing ammonium discharge and saving energy consumption.