CEE Seminar (ZOOM): Co-treatment of Landfill Leachate and Municipal Wastewater: Challenges and Opportunities

Abstract: Landfill leachate contains extremely diverse mixtures of pollutants and thus requires appropriate treatment before discharge. Co-treatment of landfill leachate with municipal wastewater in public owned treatment works (POTWs) is a common approach because of low cost and convenience. However, some recalcitrant organic compounds in leachate can escape biological treatment processes, lower the UV transmittance of waste streams due to their UV-quenching properties, and interfere with the associated UV disinfection efficacy. Thus, the leachate UV quenching substances (UVQS) must be removed or reduced to a level at which UV disinfection is not strongly affected. UVQS consist of three major fractions: humic acids, fulvic acids and hydrophilics, each of which has distinct characteristics and behaviors during treatment. This webinar will provide the state of the science regarding UVQS and possible treatment approaches. In general, chemical, electrochemical and physical treatments are more effective than biological treatments, but also costlier. Integration of multiple treatment methods to target the removal of different fractions of UVQS can aid in optimizing treatment. The importance of UVQS effects on wastewater treatment should be better recognized and understood with implemented regulations and improved research and treatment practice.

Bio: Renzun Zhao is an assistant professor of environmental engineering at North Carolina A&T State University. He earned a Ph.D. in civil engineering (environmental and water resource) from Virginia Tech in 2012. From 2012 to 2015, he gained industry experience at Veolia Water and DC Water. From 2015 to 2018, he was on the faculty at Lamar University in Beaumont, Texas.

The overarching goal of his research is to promote environmental sustainability by understanding the complex water-energy interrelationship and mitigating the environmental impacts by industrial activities, with emphasis on water/wastewater and solid/hazardous waste. His research has been sponsored by the National Science Foundation, Environmental Research and Education Foundation, Waste Management National Service and the Texas Hazardous Waste Research Center.

Zhao’s research has been published in scientific journals, including Water Research, Chemical Engineering Journal and the Journal of Hazardous Materials.