عنوان مقاله [English]
Natural organic matter (NOM) forms the group of principal precursors to organic disinfection by-products (DBPS), which have been recognized to be human carcinogens. In fact, a high TOC concentration, used as an indicator of NOM, indicates a high potential for DBP formation. The aim of the present work was to investigate the effects of nanofiltration with and without preozonation on TOC removal. Nanofiltration alone at operating pressures of 4 and 8 bars could reduce TOC levels to slightly less than 2 mgL-1, which recorded a profile of success for all the experiments. This is while preozonation at a concentration of 2 mgL-1 recorded an effluent TOC level of 3.3 mgL-1, which is not an acceptable record. Preozonation at a concentration of 4 mgL-1 increased effluent TOC to 4.2 mgL-1, which indicates that preozonation could convert NOM from higher- to lower-MW fractions, thus increasing effluent TOC. It was also shown that preozonation-nanofiltration increased effluent TOC, as compared to nanofiltration alone.