The characterisation of natural organic matter in ground water using rapid fractionation

Abstract

Natural organic matters are very common in surface and ground water, which are used for the preparation of drinking water. These compounds should be removed from water before it is ready for public consumption, whereas during the process of water disinfection natural organic matters tend to constitute disinfection byproducts. In order to choose an appropriate method for the removal of natural organic matters from water, the first objective is to find out the type of organic matters prevailing in water by using the method of rapid fractionation. The aim of this study is to identify fraction of organic compounds in groundwater and to choose the most appropriate water treatment technology. Wellfields on the coast of the Baltic Sea, surrounded by large water bodies on both sides, were chosen for the analysis. It was found that very hydrophobic acids (VHA) fraction forms the major part of organic compounds (approximately 70%) in the groundwater from Nida and Preila-Pervalka (Lithuania) wellfields. The results of rapid fractionation performed after the process of coagulation show that the highest removal efficiency is achieved in respect of the organic compounds of VHA fraction (in Preila-Pervalka – 54%, Nida – 64%).