Comparison of Methods for Isolation of Natural Organic Matter (NOM) from Loose Deposits of Drinking Water Distribution Systems

Drinking water distribution systems are overloaded with loose deposits. Natural organic matter adsorbed on these sediments affect many chemical and microbiological processes, decreasing water microbiological stability. To estimate this effect it is necessary to know the amount of organic matter adsorbed on loose deposits. The special procedure for isolation of organic matter is needed for this purpose. Aim of this work was to compare commonly used methods for extraction and analyses of organic matter in loose deposits from drinking water distribution networks. For this extraction procedures (alkali extraction methods, sonication) were tested on 11 loose deposits samples. No correlations were found between extraction methods during this study. The natural organic matter extraction method using hot NaOH in combination with non-purgable organic carbon determination method is more accurate than other methods tested in this study for measure organic matter in loose deposits