Fluorescent Dissolved Organic Matter Constituents as Surrogates for Disinfection Byproduct Formation in Drinking Water Treatment: A Critical Review

Abstract

Disinfection byproduct (DBP) formation, prediction and minimization are a crucial issue for the domestic water supply industry, which needs to provide quality and safe drinking water to consumers. Fluorescence excitation−emission matrices-parallel factor analysis (EEM-PARAFAC), is used to characterize and quantify fluorescent dissolved organic matter (DOM) in aquatic systems. EEM-PARAFAC has been identified as a potential method to predict DBP formation in treated waters. However, the method ability for specific DBP classes or species prediction is uncertain. This critical review evaluates the published literature describing empirical relationships between DOM fluorophores identified by PARAFAC components and DBP formation obtained during water disinfection. From 42 selected peer-reviewed articles, 202 established linear relationships (R2 ≥0.5) with DBP classes or species were found. Trihalomethanes (THMs) and haloacetic acids (HAAs), as regulated compounds, were extensively investigated and exhibit a strong relationship. Overall, carbonaceous-DBP classes exhibited strong relationships with humic/fulvic-like components. Conversely, a relationship between nitrogenous-DBP classes and PARAFAC components was less clear, but it was shown to be preferential to protein-like PARAFAC components in the case of algae/bacterial DOM sources. This review highlights the challenges of transposing site-specific or DOM source-specific empirical relationship between PARAFAC component and DBPs formation potential to a global model.