“Alternative Wastewater Treatment Technologies and the Distributed Low-Energy Wastewater Treatment for Fuel Generation and Water Reuse” by Dr. Kathryn Guy

Federal policies with regards to water, energy and waste are ever changing, with Army and Department of Defense (DoD) Executive orders, Army directives, public laws and other recent mandates. The primary driver is reducing water usage, energy costs and waste generation. However, a growing concern is maintaining water and energy availability at installations to enable operations in the event of an emergency. To meet current and pending mandates, alternative wastewater treatment technologies are required. The Distributed Low-Energy Wastewater Treatment (D-LEWT) for Fuel Generation and Water Reuse project will demonstrate a scalable decentralized energy-efficient wastewater treatment system.  The innovative wastewater treatment approach symbiotically integrates technologies to reduce energy consumption during treatment and generates useful fuels, hydrogen gas (H₂) and methane (CH₄). The system utilizes an Anaerobic Membrane Bioreactor (AnMBR), clinoptilolite ion-exchange and ammonia electrolysis technologies. The modular nature of D-LEWT is optimal for fixed installations that require a distributed treatment solution, and can also serve remote training areas, contingency bases and disaster relief efforts. Additionally, D-LEWT provides water that is suitable for reuse applications and generates less waste than aerobic treatment.

“Energy Sustainable Wastewater Treatment Systems for Forward Operating Bases Based on Microbial Fuel Cells” by Dr. Pat Evans

Transport of water, wastewater, fuel and treatment chemicals to and from forward operating bases is a major security risk. To greatly reduce fuel consumption, this project developed a wastewater treatment system with minimal energy requirements, based primarily on microbial fuel cells (MFCs). In MFCs, microorganisms on the anode break down organic matter in the water and produce an electrical current, coupled to oxygen reduction at the cathode. MFCs therefore simultaneously enable wastewater treatment (removal of organic matter) and power generation, not just energy consumption in a conventional process. In this project, treatment efficiency and power production of MFCs was improved by optimizing the architecture and materials, using brush graphite fiber anodes, activated carbon cathodes and spacers to provide a compact and modular design. MFC wastewater treatment reduced the concentration of organic matter (based on chemical oxygen demand) by more than 80%, while generating net power. Further polishing of the wastewater was achieved using an anaerobic fluidized bed membrane bioreactor, which has a low energy demand, to produce a filtered effluent with a low chemical oxygen demand. This water can be reused for non-potable applications, greatly reducing the need to import fuels and water at forward operating bases. 

Dr. Kathryn Guy is a materials engineer with the Engineer Research and Development Center – Construction Engineering Research Lab (ERDC-CERL) in Champaign, Illinois. Her research interests focus on lowering energy consumption and finding more environmentally friendly solutions to problems. Kathryn has led efforts to develop distributed wastewater systems as alternatives to centralized treatment and for contingency basing to help the DoD meet energy and water reduction goals. Since 2010, she has worked on a three-component system using anaerobic digestion, ion exchange and ammonia electrolysis techniques. Recently, her research has expanded into thermochromic paints for building energy savings and in-place mold preventative coatings. Kathryn received her bachelor’s degree in chemistry and mathematics from the College of William and Mary in Virginia (2001) and a doctoral degree in chemistry from the University of Illinois at Urbana-Champaign (2008). She completed an Environmental Engineering graduate certificate program with a focus on water treatment from Worchester Polytechnic Institute in 2018.

Dr. Pat Evans is a principal with CDM Smith in Bellevue, Washington. He has 30 years of research and development experience related to hazardous waste remediation, wastewater treatment, drinking water treatment and energy. Pat has been a Principal Investigator on numerous research projects including ones funded by ESTCP, Department of Energy Advanced Research Projects Agency-Energy, Water Environment Research Foundation, and the Water Research Foundation. His current research includes wastewater treatment using anaerobic membrane bioreactors and microbial fuel cells, bioelectrical conversion of carbon dioxide to biofuels, anaerobic digestion of food waste, biological treatment for drinking water production and treatment of emerging contaminants. He is the recipient of the Water Environment Federation McKee Award, two Research Grand Awards and one Superior Achievement Award from the American Academy of Environmental Engineers and Scientists. He is the author of over 40 publications and holds four patents. Pat received his bachelor’s and doctoral degrees in chemical engineering from the University of Michigan and his master’s degree in chemical engineering from Rutgers, The State University of New Jersey. He completed postdoctoral research in environmental microbiology at New York University Medical Center