ISOLATION AND FRACTIONATION OF HUMIC SUBSTANCES PRESENT IN WATER WITH THE USE OF ANION-EXCHANGE RESINS AND ULTRAFILTRATION

Abstract

ABSTRACT Natural water treatment requires emphasis on humic substances (HS) removal because of disinfection by-product formation possibilities. Thus, detailed research on HS structure and properties is necessary. Two model solutions of different origin were used in this study. A100, A200, A400, A870 and DEAE-cellulose anion exchange resins were used for the one-stage isolation of HS. Model solutions and eluates from the respective resins were subjected to filtration using regenerated cellulose 1, 5 and 10 kDa MWCO ultrafiltration membranes. The results allowed ranking of analyzed anionites according to the isolation capacity of HS: DEAE >> A870 > A100 > A400 > A200. Analysis of the HS molecular size distribution shows that hydrophilic compounds of low molecular weight (MW) are dominant in natural water, whereas in the Aldrich humic acid solution and in the eluates after each resin, large MW hydrophobic compounds are predominant.