Aleksandra Tubic
University of Novi Sad, Republic of Serbia
Title: Evaluation of solid-phase chromatography as a method for natural organic matter characterization
Biography
Biography: Aleksandra Tubic
Abstract
Natural organic matter (NOM) is a ubiquitous constituent of surface and ground waters worldwide. It is well known that various inorganic and organic species interact with NOM in water matrices and these interactions can have a great impact on their mobility and behaviour, as well as the expression of toxic effects. NOM, if present in source water, can have a great negative influence on drinking water treatment, through disinfection by-products formation, requirements for increasing amounts of chemicals during treatment and deterioration of water quality in the distribution system. NOM is generally site specific, and the approximation of its influence is rather difficult to make based on simulations or previous knowledge gained from other sites. Thus, the characterization of NOM at the specific site of interest is of great help in understanding the processes in ambient waters as well as during treatment. There are various possibilities for NOM characterization, including solid-phase fractionation using XAD resins. The aim of this paper is to evaluate solid-phase chromatography as a method for NOM fractionation through a review of the results obtained by fractionation of 3 ground waters and 1 surface water, which was repeated 2-5 times for each water. The method is based on fractionation of the dissolved organic matter into four fractions: The humic acid, fulvic acid, hydrophilic acid and hydrophilic non-acid fractions; and measuring the DOC value after the fractionation. The fractionation method showed great recovery values for DOC (> 98%) compared to the DOC measured in the bulk water samples. The relative standard deviations (RSD) of the DOC values measured in the same fraction in each water sample range from 0.71-9.9%. An additional benefit of the method is that it gives satisfactory recovery results even after resin regeneration, with recoveries of 99%, 97% and 88%, for the resins used before and after the first and second regeneration cycles.