1. Fate of Organic Matter from Leachate Discharged to Wastewater Treatment Plants

Leachate management is an expensive and challenging task for landfill operators. Wastewater treatment operators are increasingly refusing to accept leachate due to operational challenges even though the specific impacts on effluent quality are not well understood. The goal of this proposed research is to study the nature and fate of recalcitrant, UV-absorbing, and nitrogen-containing organic compounds in leachate that is co-treated with domestic wastewater. This research will provide a better understanding of the potential implications of accepting leachate at domestic wastewater plants. Additionally the impediments to UV disinfection in the presence of leachate organic matter will be better understood and recommendations will be made to ensure that the performance complies with discharge permit requirements. For more information, visit the project webpage.

2. MSW Leachate Organic matter Generation and Removal

This research will examine the chemical nature of LOM to better understand the humification of landfilled waste and the fate of discharged LOM to the environment after in situ landfill treatment, co-treatment at a WWTP, or on-site biological treatment. Our hypothesis is that recalcitrant LOM production is associated with specific components of solid waste, and that the avoidance of these components in future landfills could result in enhanced leachate treatability and reduced treatment cost. We further hypothesize that the consequences of discharging LOM in treated leachate from existing landfills can be attenuated through passive sunlight-driven photolysis. Specific research questions to be addressed include the following: (1) which waste components contribute to recalcitrant LOM; (2) can we use advanced characterization tools to better understand the potential for LOM biodegradation, photolysis, or contaminant transport; and (3) what is the fate of recalcitrant LOM in aquatic environments (e.g., wetlands and surface waters), with a focus on photolysis? This research will be accomplished by well characterizing LOM, conducting microcosms examining the evolution of LOM from waste components, and evaluating LOM photolysis of leachate samples irradiated by natural sunlight and a solar simulator.

Intellectual Merit
This research addresses the management of a particularly challenging constituent of leachate from landfills, leachate organic matter (LOM), with the goal of reducing the long-term risks and costs associated with landfill operation. This research is transformative because, for the first time, information will be provided that may lead to the control of LOM that passes through biological treatment systems. Further, by providing information regarding the potential for natural systems to assimilate low level contributions of non-biodegradable LOM from closed landfills, society may be relieved from long-term financial burdens of landfill post-closure care (PCC). A better understanding of LOM fate and behavior can provide regulators with the information needed to confidently approve reducing or terminating landfill PCC.

Broader Impacts
The proposed research has clear societal benefits associated with reduced cost and risk of landfills, a greater understanding of leachate discharges to the environment, and more sustainable solid waste management. The broader impacts of this proposed research also include the advancement of understanding of chemistry and photochemistry of organic matter. The proposed research is a multidisciplinary project that involves a diverse group of female researchers, bridging environmental engineering and physical science fields and impacting multiple areas of the scientific community. The doctoral researcher assigned to this project is a female minority student, contributing to diversity in the science and engineering workforce. Outreach to art and design students through UCFSTEAM will also provide broader impacts. Researchers’ involvement with K-16 students provides an opportunity to increase STEM understanding and participation. Many of K-16 students who have worked with the PI in the past have been female and/or under-represented in engineering.

3. Food Waste at the Food/Energy/Water Nexus

We propose exploratory research focused on the energy and water footprints of wasted food, with particular attention to the uncharted and highly coupled water and energy impacts of food waste management. We will apply life cycle and water footprint analyses under various scenarios of consumption and disposal to evaluate energy and water costs associated with strategies of food waste management. Understanding water and energy costs on both conceptual and quantitative levels will facilitate comprehension of food waste as a driver of water consumption and contamination, as well as a potential source or sink for energy. The consumption/contamination profiles of water and energy related to various management strategies and magnitudes of food waste can be communicated to consumers through public education, potentially altering human behavior and creating a dynamic coupling of information and action. In this work, we will identify issues that may be addressed in further detail in subsequent response to a FEW solicitation.