Immediate detection of sewage spills is imperative to minimizing the risk of introducing large quantities of pathogens in urban watersheds. For example, in February 2017, a fracture in a sewage collector pipe in the Tijuana River resulted in nearly 143 million gallons of raw sewage being transported into the ocean over a period of over two weeks. Research has shown that fluorescence spectroscopy is capable of tracking anthropogenic, microbial sources of dissolved organic matter (DOM), but less is known about the applications of in situ fluorescence sensors for real-time water quality monitoring of sewage inputs. The fluorescent properties inherent in some DOM compounds, such as aromatic amino acids, humic and fulvic acids, and organic chemicals, facilitate their identification when they emit radiation in the ultraviolet and visible spectrum. Specifically, the fluorescence of tryptophan has proven to have a positive correlation with CDOM. Previous storm water sampling at Alvarado Creek on the San Diego State University Campus demonstrated that tryptophan-like fluorescence intensity measured with a benchtop fluorometer was significantly correlated to total aerobic bacteria counts (R2 of 0.71 and p &lt; 0.01) and total coliforms (R2 of 0.65 and p &lt; 0.01) during storm events in February 2017. Based on this earlier study, current research evaluates whether an in-situ, submersible fluorometer can yield similar relationships with bacterial numbers in surface water and rapidly detect the presence of wastewater in riverine environments and other source waters. This current project introduces wastewater obtained from a wastewater treatment plant to surface water collected from Alvarado, mimicking a sewage spill, and subjects the sample to the same set of analyses as the storm event. The data collected is essential to understanding the extent to which fluorescence spectroscopy can be used as a warning system in the event of a sewage spill by monitoring water quality in real time.

Fluorescence based monitoring of sewage inputs to urban rivers

255th National Meeting (2018)

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