THE EFFECT OF DIFFERENT OXIDATION AND FILTRATION PROCESSES ON THE MOLECULAR-SIZE DISTRIBUTION OF HUMIC MATERIAL

The effect of different oxidation and filtration processes on the amou nt and character of organic matter in drinking water was studied. TOC, KMnO4 value, colour and fractions of humic material were analyzed fro m bank filtrated lake water, chemically coagulated and sand filtrated water, ozonated, O3/H2O2 treated, chlorinated, granular activated carb on (GAC) filtrated and nanofiltrated water. Size exclusion chromatogra phy was used to separate different fractions of humic molecules. Six d ifferent fractious were found from bank filtrated lake water and from chemically coagulated and sand filtrated water. The molecular weight o f humic fractions ranged from about 1000 (the last fraction) to about 100 000 dalton (the first fraction). Most of the humic molecules of ba nk filtrated lake water were found in the third and fourth fractions. After the oxidation and filtration processes the first fraction of hum ic molecules disappeared completely and the fourth and fifth fractions dominated. The total sum of the humic fractions was most effectively reduced alter the O-3/H2O2 treatment, by about 70%.