Quantitative Models and Potential Surrogates for Rapid Evaluation and Surveillance of Chlorine Disinfection Efficacy in Reclaimed Water

Abstract

Nowadays, chlorine disinfection is the most widely applied and indispensable technology in wastewater treatment and reuse to mitigate microbial risk and guarantee water safety. However, owing to complexities and high concentrations of contaminants in reclaimed water, rapid evaluation of chlorine disinfection efficacy is a crucial but challenging issue. Based on intensive experimental and statistical analyses, this study has established kinetic models and potential surrogates for rapid indicating inactivation of microbial indicators and opportunistic pathogens during chlorine disinfection in different reclaimed waters. Overall, the constructed Selleck models performed very well to simulate log removal values (LRVs) of fecal coliforms, Pseudomonas aeruginosa and HPC in all reclaimed water samples (R2=0.877-0.990). Moreover, total and peak A fluorescence intensity as well as fluorescence integral intensities in Regions II and IV were found to have high response sensitivities over chlorination process. Nevertheless, their effectiveness to act as potential surrogates of LRVs of microbial indicators need to be further validated. The results from this study can provide valuable information in microbial safety surveillance over disinfection towards sustainable and long-term water reuse.

Keywords: Chlorine disinfection, Reclaimed water, Kinetic models, Surrogates, Fluorescence intensity.