Civil and Environmental Engineering - Master Calendar

Abstract

Conventional wastewater management has delivered enormous public health benefits. Yet it still largely follows a linear model: we build extensive pipe networks and centralized treatment plants, expend energy and chemicals to remove contaminants, and landfill residuals, while valuable nutrients and energy are lost. Today, aging infrastructure, tightened water quality limits, and the need for resource circularity are exposing the limits of this paradigm and accelerating the push toward resource recovery.

In this seminar, I will present my research on process-level innovation in electro-algal processes and system-level prioritization of research, development, and deployment (RD&D) pathways for emerging resource recovery technologies. Drawing from the lessons of the world’s first full-scale tertiary algal processes for nutrient recovery from low-strength municipal wastewater in Wisconsin, I will highlight processes that can address the challenges of low effluent quality, algal biomass contamination, and high capital cost. I will then turn to high-strength sidestreams such as municipal biosolids, where I develop electrochemical approaches, including electrolysis-assisted precipitation and electrodialysis, to recover phosphorus efficiently and/or selectively as fertilizer or fertilizer feedstock.

To navigate the broader RD&D landscape of sanitation and resource recovery technologies, I will demonstrate the application of a methodology, quantitative sustainable design, that integrates process modeling, life cycle assessment, and technoeconomic analysis under uncertainty. I will share results from the evaluation of the Gates Foundation’s latest Generation II Reinvented Toilet, and the financial benefits and effluent impacts of three emerging nitrogen recovery technologies, urine diversion, mainstream hydrogel ammonium adsorption, and electrochemical stripping, on 18 full-scale wastewater treatment configurations.

Overall, my work aims to advance water resource recovery systems that increase circularity, reduce environmental impacts, and strengthen the resilience of sanitation services across both centralized and decentralized contexts.

Biography

Dr. Zixuan Wang is a postdoctoral research associate at the University of Illinois Urbana-Champaign. He earned his PhD in Energy, Environmental & Chemical Engineering from Washington University in St. Louis, where he specialized in electrochemical phosphorus recovery from anaerobically digested sludge. Trained as an environmental engineer, Zixuan’s research bridges electrochemical separations, algal biotechnology, and system-level analysis to advance sustainable water resource recovery. 

Zixuan has authored 25 peer-reviewed publications, including 12 as lead author, in journals such as Environmental Science & Technology and Water Research. He has received multiple national honors, including the Association of Environmental Engineering and Science Professors Outstanding Doctoral Dissertation Honorable Mention and the W. Wesley Eckenfelder Graduate Research Award.