There are a great number of effluent derived chemicals (including pharmaceuticals and personal care products (PPCPs)) that may persist through traditional wastewater treatment methods (primary and secondary treatment) and enter the environment in effluent discharged to receiving waters. The chemicals that are persisting through traditional treatment have the potential to pose risk of ecotoxicological harm to both aquatic organisms and humans alike. Sunlight is known to photodegrade compounds, both directly and indirectly, by oxidizing the compounds, producing reactive radicals that can degrade compounds, and transform compounds to smaller and more labile compounds that can be degraded by microorganisms. The purpose of this study was to evaluate the photo transformation of organic matter, photodegradation of trace organic contaminants, and evaluate the role that microorganisms play in mineralization using laboratory experiments to simulate treatment in polishing ponds. To achieve this goal, we conducted a set of photoirradiation experiments using solar simulation of natural sunlight and dark conditions (control) with sterile-filtered (bacterial free) and unfiltered samples of secondary wastewater effluent. The effluent was collected from a wastewater treatment plant in North County, San Diego, that uses activated sludge for secondary treatment. Half of the effluent was filtered to remove microbes and the other remained unfiltered, and both sets were exposed to simulated sunlight and dark conditions. We used a non-targeted analysis based on comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS) to quantify the number of chromatographic features present under different experimental conditions and to determine behaviors of chemicals by exposure to sunlight in the presence and absence of microbes. Data analysis is in progress.

Persistence, removal, and transformation products of emerging chemicals in sunlight-exposed wastewater effluent

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.