The funds from this year’s Paul L. Busch Award will be used to develop new approaches for quantifying the fate of chemical contaminants in wastewater treatment systems. This research will help provide the water community with the tools it needs to develop new treatment methods, and to optimize existing conventional and advanced treatment processes to remove wastewater-derived chemicals. Ultimately, this research could lead to new, cost-effective solutions for producing water that can be discharged into wastewater-dominated rivers, and into the surface and ground waters that serve as potable water supplies.

During the past three decades, environmental engineers have solved many problems associated with oxygen demand, nutrients, and pathogens in municipal wastewater. But recently, a new set of problems has cropped up to take their place: It has become apparent that more research needs to be done to meet all of the challenges posed by wastewater-derived chemical contaminants. These contaminants might include hormones, pharmaceuticals, and chemicals formed during the wastewater treatment process.

Researchers have found fish feminized by hormones in wastewater effluents and carcinogens have been detected in wells injected with recycled water. The water community is facing a new challenge. It is unclear how best to design the next generation of treatment plants to protect public health and the environment from an ever-expanding suite of chemicals that, now, we are barely able to measure.

Recent research has indicated that it will not be possible to design cost-effective treatment processes to remove wastewater-derived chemical contaminants simply by using existing methods or by installing membrane-based treatment processes. Instead, this emerging class of pollutants will necessitate a new understanding of the ways in which chemicals are removed.Wastewater engineers will need to design new treatment technologies to remove trace amounts of chemicals.

This research project will help complete one necessary step toward that goal. Sedlak and his colleagues will develop a family of easily measured chemical probes, each of which will be susceptible to removal by a different mechanism. Some of the probes will be non-toxic compounds that can be added before different treatment processes; others will be compounds that already are present in wastewater effluent. By measuring the removal of the probes as operating conditions are varied, it will be possible to identify the conditions that are most conducive for the removal of wastewater-derived chemical contaminants.

During the initial phase of the research, the researchers will develop the probes and test them for use in two types of systems: the advanced oxidation systems employed after reverse osmosis treatment and systems that employ natural attenuation (such as engineered treatment wetlands and groundwater infiltration systems). After this research is completed, academic researchers and practicing engineers will have the tools necessary to design a system of multiple barriers to assure reliable and cost-effective removal of chemical contaminants—both those that are currently in the public consciousness, and those that have yet to be discovered.

The discovery of wastewater-derived chemical contaminants has made the water industry more complicated. But as Paul Busch's career demonstrated, any challenge can be met with innovative research and partnerships between academic researchers and practicing engineers.