Natural organic matter characterization by HPSEC and its contribution to trihalomethane formation in Athens water supply network

ABSTRACT

Samples from the two main watersheds that provide Athens Water Supply and Sewerage Company (AWSSC) with raw water were examined for Dissolved Organic Carbon (DOC) and for their molecular weight distribution (MWD). In addition, water samples from water treatment plants (WTPs) and from the water supply network were examined for trihalomethane (THMs) levels. The main purpose of this study was to reveal the molecular composition of natural organic matter (NOM) and identify the individual differences between NOM from the two main Athens watersheds. High-performance size exclusion chromatography (HPSEC), a relatively simple technique, was applied to determine different NOM fractions' composition according to molecular weight. Various THM levels in the supply network of Athens are illustrated as a result of the different reservoirs' water qualities, and a suggestion for a limited application of chlorine dioxide is made in order to minimize THM formation.

KEYWORDS:

• Chlorination
• chlorine dioxide
• high-performance size exclusion chromatography
• natural organic matter
• trihalomethanes

Acknowledgment

The authors would like to thank the Quality Control Department of Athens Water Supply and Sewerage Company (AWSSC) for the collection of the samples and for the provision of the instruments.