Integrated microbial fuel cell and hydrogel system for nitrogen removal from stormwater

Overview

This solution combines a nitrogen-absorbing hydrogel with 3D cathode microbial fuel cell (MFC) technology to capture and remove nitrogen from stormwater and wastewater. The hydrogel acts as a passive collector, absorbing and accumulating nitrogen as stormwater passes through it. The integrated MFC then breaks down the accumulated nitrogen through simultaneous nitrification and denitrification, converting it into harmless nitrogen gas. The system has been shown to remove more than 90% of total nitrogen from real wastewater streams and is designed to be scalable from laboratory to industrial deployment.

Technical specifications

Core components:

• Hydrogel absorption layer: Engineered to selectively absorb and accumulate nitrogen compounds from stormwater runoff, providing a concentrated feedstock for downstream treatment.
• 3D cathode microbial fuel cells (MFCs): Bioelectrochemical devices that use microbial activity to drive simultaneous nitrification and denitrification, removing accumulated nitrogen without the need for external chemical inputs.
• Integrated system design: MFC units and hydrogel modules are configured to work together, enabling continuous capture and treatment of nitrogen in a single process flow.

Key features:

• Removes over 90% of total nitrogen from municipal and dairy wastewater
• Passive nitrogen capture via hydrogel, reducing the treatment load on the MFC stage
• Scalable architecture suitable for industrial-scale water treatment
• Chemical-input-free nitrogen removal through bioelectrochemical processes

Technology readiness level

The underlying technologies have been individually validated: the hydrogel absorption capacity has been tested, and 3D cathode MFCs have been demonstrated on municipal and dairy wastewater with greater than 90% total nitrogen removal. A full-scale demonstration was deployed in a public show garden visited by more than 100,000 people, and key findings have been published in a peer-reviewed journal. The next stage of validation involves configuring MFC units, producing hydrogel, integrating the two subsystems, and testing the combined system with rainfall simulators over an eight-month period to confirm performance under realistic stormwater conditions.