Occurrence of THM and NDMA precursors in a watershed: Effect of seasons and anthropogenic pollution

• Published in: Journal of hazardous materials Vol. 221-222; pp. 86 - 91
• Main Authors: Aydin, Egemen, Yaman, Fatma Busra, Ates Genceli, Esra, Topuz, Emel, Erdim, Esra, Gurel, Melike, Ipek, Murat, Pehlivanoglu-Mantas, Elif
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 30.06.2012
• Subjects: ammonia; Byproducts; chlorides; chlorination; Correlation; Dimethylnitrosamine - analysis; disinfection; Disinfection by-products; Drinking water; lakes; LC–MS/MS; N-nitrosodimethylamine; nonpoint source pollution; organic matter; Organic nitrogen; Pollution abatement; Precursors; Quality Control; seasonal variation; Seasons; Spectrophotometry, Ultraviolet; Tributaries; Trihalomethanes - analysis; Water Pollutants, Chemical - analysis; Water pollution; water quality; water treatment; Watershed; watersheds; Turkey, Istanbul; Drinking water; Disinfection by-products; Organic nitrogen; LC–MS/MS; Watershed
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2012.04.012

► Precursors of THM and NDMA were evaluated in a watershed. ► High concentrations of THMFP and NDMAFP were detected. ► Pollution (point or diffuse) in addition to NOM may act as DBP precursors. ► No relationship between DBP precursors and water quality parameters was detected. ► Spatial effects are more important than the effect of the seasons. In pristine watersheds, natural organic matter is the main source of disinfection by-product (DBP) precursors. However, the presence of point or non-point pollution sources in watersheds may lead to increased levels of DBP precursors which in turn form DBPs in the drinking water treatment plant upon chlorination or chloramination. In this study, water samples were collected from a lake used to obtain drinking water for Istanbul as well as its tributaries to investigate the presence of the precursors of two disinfection by-products, trihalomethanes (THM) and N-nitrosodimethylamine (NDMA). In addition, the effect of seasons and the possible relationships between these precursors and water quality parameters were evaluated. The concentrations of THM and NDMA precursors measured as total THM formation potential (TTHMFP) and NDMA formation potential (NDMAFP) ranged between 126 and 1523μg/L THM and <2 and 1648ng/L NDMA, respectively. Such wide ranges imply that some of the tributaries are affected by anthropogenic pollution sources, which is also supported by high DOC, Cl− and NH3 concentrations. No significant correlation was found between the water quality parameters and DBP formation potential, except for a weak correlation between NDMAFP and DOC concentrations. The effect of the sampling location was more pronounced than the seasonal variation due to anthropogenic pollution in some tributaries and no significant correlation was obtained between the seasons and water quality parameters.