2025-26 AEESP Distinguished Lecturer

Professor Sedlak will present two lectures in the 2025-2026 Tour.  Abstracts are below.

Lecture 1: "Using Small-Scale Treatment Systems to Solve Some of the World's Water Crises"

The creation of treatment systems capable of removing contaminants from water has been one of the most impactful achievements of environmental engineers. Because most of these technologies benefit substantially from economies of scale, centralized systems that involve expensive, vulnerable infrastructure usually have proven to be the most cost-effective means of improving water quality. Recent developments in manufacturing, sensing, materials science and biotechnology have the potential to alter this dynamic, enabling the deployment of small-scale treatment systems within existing water networks as well as the creation of autonomous "off-the-water-grid" systems. This lecture will introduce audiences to the latest developments in small-scale water systems by examining premise-scale water recycling systems and the potential for further deployment of such systems in other settings. By leveraging recent developments in small-scale treatment systems that do not require on-site operators or replenishment of chemical reagents, it may be possible to lower costs of water treatment and extend the benefits of modern water treatment to rural communities and citizens of low- and middle-income countries.

Lecture 2: "Using Nature-Based Treatment to Solve Some of the World's Water Crises"

The creation of treatment systems capable of removing contaminants from water has been one of the most impactful achievements of environmental engineers. Because regulations usually assume uniform temporal performance and water infrastructure tends to be built in places where space is limited, the technologies used in modern treatment plants usually consist of mechanical devices (i.e., unit processes) for which conditions are rigorously controlled. In contrast, nature-based treatment systems employ physical, chemical and biological processes to improve water quality in larger spaces. They also exhibit temporal fluctuations in performance. If environmental engineers can develop the ability to predict, manipulate and enhance the performance of nature-based treatment systems, it may be possible to reduce the costs of this approach while simultaneously providing co-benefits that are increasingly important to decision makers and members of the public. To illustrate the potential for making nature-based treatment systems a more attractive option, this talk examines the treatment of effluent-dominated surface waters and reverse osmosis concentrate from water recycling projects with two new types of constructed wetlands. By understanding the mechanisms of contaminant removal, quantifying co-benefits and realistically articulating the tradeoffs associated with these systems, environmental engineers may be able to address some of the world's greatest water challenges.