Abstract
Mutagenicity test of humics after chlorination was carried out according to the liquid-cultivation method of Bacillus subtilis rec-assay.
An increase in mutagenic activity was observed with the increase of Cl2/TOC in the range of Cl2/ TOC = 1 10.
The DEAE Sephadex A-25 anionic exchange chromatography was employed for the fractionation of humic water before and after chlorination to characterize the mutagenic compounds. Chlorinated humics were fractionated into the nonanionic fraction (Group 1), the weak anionic fraction (Group 2), and the strong anionic fraction retained in column (Group 3). It was found out that mutagenic compounds are hydrophobic compounds extractable by dichloromethane in non-anionic fraction (Group 1).
