Understanding Organic Nonpoint‐Source Pollution in Watersheds via Pollutant Indicators, Disinfection By‐Product Precursor Predictors, and Composition of Dissolved Organic Matter

• Published in: Journal of environmental quality 2019-01, Vol.48 (1), p.102-116
• Main Authors: Zhang, Yixiang, Liang, Xinqiang
• Format: Article
• Language: English
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq2018.06.0228

The analytical techniques and instrumentation used to assess agricultural and rural nonpoint‐source organic pollution loading are usually complex and expensive. There has been a strong demand for alternative methodologies to determine the presence and composition of organic pollutants and to predict their levels. In the current work, we investigated a simple and inexpensive approach combining excitation–emission matrix and support vector machine that measures pollution and predicts the levels of precursors to disinfection by‐products, which are organic pollutants derived from agricultural and rural nonpoint sources in small watersheds. Through parallel factor analysis, a four‐component model was developed to explain the composition of dissolved organic matter in water impacted by nonpoint‐source pollution. Support vector classification and support vector regression with model components can use fluorescence properties as proxy indicators for nonpoint‐source pollution. When the model components are used as input variables, formation potential of disinfection by‐products can be predicted. This method provides water utilities managers with tools to control pollution, supervise aquatic environments, and ensure the safety of drinking water. Core Ideas Parallel factor (PARAFAC) components are indicators of nonpoint‐source pollution. PARAFAC components can predict disinfection by‐product (DBP) formation potential (FP). Correlation among DBP FPs and PARAFAC components was visualized by ordination diagram. Effects on FPs across PARAFAC components were visualized by ordination diagram. Humic‐ and protein‐like substances were origins of organic nonpoint‐source pollution.