Faculty Directory

It is unknown what the nitrogen release rate is of a new type of biosolid (a wastewater residual) now used in fertilizers. The goal is to determine proper application rates to guard against excess nutrient use. As biosolids are a recycled material, they can also contain trace levels of organic contaminants, such as pharmaceutical and personal care product compounds. The project will also explore how these compounds sorb between biosolids, soil, and dissolved phases. In addition, microbes that could beneficially degrade PPCPs at wastewater treatment facilities will be examined.​ More information about this project is available online.

The sediment microbial fuel cell (SMFC) generates electrical power by oxidizing organic matter in marine sediments using oxygen in the water. SMFCs exploit the naturally occurring transition from oxic water to anaerobic sediment in marine environments. In wastewater treatment plants (WWTPs) there is a similar environment, which opens up the possibility for power generation. As much as 50 percent of energy consumed by WWTPs is for the aeration of wastewater to oxidize organic matter. Here we investigated whether an SMFC can be configured to oxidize organic matter in wastewater, therefore reducing a treatment plant’s energy consumption while producing useful power. More information about this project is available online.

This modeling project uses data from the Vegetative Environmental Buffers experiments to modify a gaussian plume model to predict the concentration distribution of particulate matter, volatile organic compounds, and ammonia released from the fan of a poultry house. This model will be used to compare simulated conditions when there is no vegetative buffers and measured conditions when there is vegetative buffer. This work will be used to support assumptions that vegetative buffers can decrease the concentration of pollutants released from by the fan. More information about this project is available online.

The project focuses on the fate of organic pollutants throughout the wastewater treatment process; more specifically, how various treatment processes, such as activated sludge, nitrification, and anaerobic digestion, influence contaminant concentrations and formation of degradation products. This research is done in conjunction with DC Water and the USDA. More information about this project is available online.

Several highly persistent organic pollutants have been extensively used by industry and agriculture. While many of them have been banned, many sites still contain levels that pose ecological risks. Here, we are investigating if adding organic amendments will reduce the bioavailability of POPs, such as DDT, in soil. We use a combination of field and laboratory studies. If proven efficient, it will be a much more environmentally friendly form of remediation than methods currently used. We are also working on the development of a chemical methodology to determine POPs bioavailability and thus, potential risk. More information about this project is available online.

During 2015, DCWater installed a new process that produces Class A biosolids product, which can be safely used as a fertilizer in homes and urban areas. The process is a combined thermal hydrolysis and anaerobic digestion and the impact of this new process in the concentration of persistent organic pollutants is widely unknown. This research project aims to identify the impact of this new process in PBDE concentration in the new Class A biosolids compared to the previous process which produced Class B material. Though Class A material produced always meets regulations set by EPA, organic pollutant presence or absence may be useful information in the use of this product for certain applications. Moreover, once the impact of this new process is known, it may be easier to predict the concentrations and impact on similar chemicals. More information about this project is available online.

Application of biosolids to agricultural fields provides a ready source of nutrients instead of using commercial fertilizers. However, there are concerns regarding odors caused by specific volatile organic compounds, which can lead to public opposition and failure of biosolid application programs. The goal of this research is to increase the understanding of odor related compound formation and release from biosolids at an advanced wastewater treatment plant, and on the use of on-line odor monitoring technology (E-nose). The results of this research will support decision-making tools for reducing odors in the final biosolids material. More information about this project is available online.