Jacob Novitch

Civil & Environmental Engineering & Earth Sciences

Faculty Advisor: Rob Nerenberg

Effect of Hydroxylamine on the Structure and Function of Nitrifying Biofilms

This project is in the process of studying a novel, biofilm-based treatment technology for wastewater treatment. Funding for the project has been provided from a Slatt Fellowship for Fall 2020, and continued funding will support further research and later stages of the project, detailed below. Wastewater treatment is a major energy sink, accounting for 2 - 4% of electrical energy consumption in the United States. The proposed treatment could greatly reduce these energy demands, or even make wastewater treatment energy positive. The Nerenberg group proposes a new biofilm process combining gas-permeable membranes with water- permeable membranes. The gas-permeable membranes supply O2 with nearly 100% efficiency. The water-permeable membranes supply a chemical to alter the microbial community of the biofilm growing on the membrane assembly. Specifically, it is proposed that supplying hydroxylamine, which the group hypothesizes can alter the biofilm community in ways that reduce the O2 requirements and allow more wastewater organic matter to be directed to the anaerobic digesters. These anaerobic digesters produce methane, an energy carrier that can be used to fuel cars, produce electricity, or provide heat.

Initially, the project is examining delivery of chlorate through a hollow fiber membrane in order to select for perchlorate reducing bacteria in the biofilm community. This approach has proven effective in other applications, and will provide insight into the effectiveness of chemical delivery through a membrane as proposed in this project. Currently, a baseline microbial community has been established and chlorate addition has begun. Resulting changes in the microbial community after chlorate addition will be observed to determine the effects of chlorate delivery through the membrane on the microbial community. Following the conclusion of this phase of the project, a similar approach will be taken to evaluate the effects of hydroxylamine addition on the microbial community of the biofilm, growing a baseline biofilm and monitoring changes to the biofilm upon addition of hydroxylamine. The information gathered from this research has the potential to significantly reduce energy demand in wastewater treatment, thus lowering costs and improving environmental conditions.