LEAVE NO TRACE: REMOVING TRACE ORGANICS FROM WASTEWATER VIA DIRECT AND INDIRECT PHOTOLYSIS

Abstract

Trace organic contaminants (TOrCs) are a diverse group of chemicals that are found in wastewater effluent. These compounds pose environmental and human health risks, making their removal critical. Current removal methods are both energy-intensive and expensive. Natural TOrC attenuation has been observed by the University of Arizona's Saez research group in the Santa Cruz River (SCR). However, this process poses several challenges due to the lack of experimental control and has yet to be replicated in the engineering world. The objective of this project was to design, build, and test an experimental setup to degrade TOrCs from Agua Nueva Water Reclamation Facility (ANWRF) effluent and use data to make low-cost treatment recommendations with concentration modeling. This involved designing two separate bench-scale systems: a 254-nanometer wavelength UV reactor manifold and a solar-exposed pool. Key design variables include residence (treatment) time and path length (depth). Samples were tested at different residence times and analyzed for TOrC concentration. Given severe equipment error, results were inconclusive. Energy use comparisons were made for the two systems, as well as approximated scaled-up designs. Future experimentation is recommended with longer residence times, combining the two processes in series, and varying the feed water.