Distributed Low-Energy Wastewater Treatment (D-LEWT) for Fuel Generation and Water Reuse
Dr. Kathryn Guy | ERDC-CERL
The objective of this project is to demonstrate and validate a distributed low-energy wastewater treatment (D-LEWT) system that enables water reuse and converts black water contaminants into harvestable fuels, hydrogen (H2)and methane (CH4), for energy generation. Successful implementation of this technology will support both the DoD net zero energy and net zero water goals.
The D-LEWT project will demonstrate a scalable decentralized energy-efficient wastewater treatment system at Mountain Home Air Force Base. The innovative approach symbiotically integrates technologies to treat wastewater in a manner that reduces energy consumption and generates useful fuels. The system is made up of three major subsystems: (1) anaerobic membrane bioreactor (AnMBR), (2) clinoptilolite ion-exchange, and (3) ammonia electrolysis. Each of the three subsystems is briefly described below.
- AnMBR: The AnMBR degrades organics in wastewater and generates methane during the process. The methane can be harvested for electrical and thermal energy generation.
- Clinoptilolite ion-exchange: Clinoptilolite, a naturally occurring ion-exchanging zeolite, removes ammonia from the AnMBR treated water. The sequestered ammonia becomes the feedstock for the ammonia electrolysis process.
- Ammonia electrolysis: Ammonia electrolysis converts the ammonia into nitrogen and hydrogen gases. The hydrogen gas is available for capture and energy generation.
The D-LEWT system’s success will be measured on its ability to meet operational metrics and its favorable comparison to traditional wastewater treatment technology. The quality of treated water will be suitable for low-tier reuse applications. Favorable energy savings compared to traditional treatment methods are expected from D-LEWT’s higher operational energy efficiency and the conversion of produced fuels to energy.
Successful implementation of this technology will support both the DoD net zero energy and net zero water goals. It is estimated that the DoD currently spends $250 million dollars per year treating wastewater. The D-LEWT system reduces the energy used to treat wastewater by 80% compared to traditional aerobic based systems. Additional energy savings can be realized by utilizing the generated methane and hydrogen as fuel sources. The D-LEWT system treats water to a quality suitable for reuse applications, such as irrigation, which would reduce the water demand of the site. The modular nature of D-LEWT is optimal for fixed installations requiring a distributed treatment solution and can also serve remote training areas, contingency bases, and disaster relief efforts. The D-LEWT system benefits the DoD with a distributed low-energy wastewater treatment system that enables water reuse and converts wastewater contaminants into harvestable fuels for energy generation. (Anticipated Project Completion - 02/2020)