Haloacetonitriles (HANs) are a group of disinfection byproducts (DBPs) formed during drinking water disinfection that are important contributors to drinking water toxicity. Recent studies show that HAN formation is increased when the treated wastewater discharged from upstream treatment plants are present in the water supply that is treated for potable use. Therefore, it is desirable to develop a watershed scale model to predict the risks of HAN formation based on the presence of upstream treated wastewater discharges and the drinking water disinfection processes. This collaborative study between SUNY at Buffalo and Arizona State aims to fill the knowledge gaps that have prevented the development of such a model. Specifically, this study will be the first to determine the rates at which treated wastewater discharges alter the potential formation of HANs due to environmental degradation processes. The experimentally determined parameters will then be applied in regional or national scale water quality models. Additionally, a data science course will be introduced in the environmental engineering curriculum at Arizona State University. A two-semester, cross-course student project spanning modeling and water treatment will be developed at the University at Buffalo. If successful, the development of these models will help aid in the protection of the Nation's water security while monitoring the effects of various water treatment processes.
De facto reuse, or indirect potable water reuse, the incidental presence of treated wastewater effluent in downstream drinking water supply, is increasing with urbanization worldwide. The proposed project aims to develop a comprehensive understanding of the risks associated with HANs under de facto wastewater reuse scenarios on the watershed and national scale. It has four research objectives: (1) Determine the HAN risks associated with wastewater effluents as a function of wastewater treatment process and isolate the contribution from wastewater organic matter and inorganic constituent bromide; (2) Determine the influence of biological and photochemical transformation of organic matter on the wastewater-derived HAN risks; (3) Integrate experimental findings into the geospatial DRINCS model to assess wastewater-derived HAN risks for all water treatment plants supplied by surface water in the U.S. (4) Compare model predictions from DRINCS with regional hydrodynamic models to validate the simplifications made in DRINCS or estimate the associated error. This project is the first effort to quantitatively assess wastewater-derived HAN risks on the national scale. Although it focuses on HANs, the framework of integrating experimental research with modeling is transferrable to other high priority emerging DBPs and contaminants derived from wastewater. The outcome of this project will inform the nationwide HAN risks due to de facto reuse, and potentially provide strategies for wastewater and water utilities to collaboratively address DBP problems.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
