Assessment of Halonitromethanes Formation Potentials Under Different Disinfection Scenarios in Low SUVA Water

The main objective of this project is to investigate the formation of halonitromethanes, an emerging class of disinfection by-products (DBPs) identified in drinking waters in recent years, which are currently unregulated but highly toxic. Halonitromethanes formation potentials tests were investigated under five different disinfection conditions in Egirdir Lake with low specific ultraviolet absorbance (SUVA) value. The results showed that ozone/chlorine formed the highest halonitromethanes followed by in the order of ozone/chloramine and chlorine only. When chloramine or ozone were used alone, the halonitromethanes concentration was below the minimum detection limits. The highest halonitromethanes was determined 2.5 µg/L for ozone /chlorine scenario and the lowest halonitromethanes concentration was 1.7 µg/L in ozone /chlorine scenario. In the ozone/chlorine scenario, a dramatic decrease for halonitromethane formation was detected from spring to winter. Chloropicrin has been the only measurable halonitromethanes species. In the correlation analysis between halonitromethanes and water quality parameters, the highest correlation was found between halonitromethanes and dissolved organic nitrogen. Besides dissolved organic nitrogen, different organic/inorganic compounds and disinfectants also contribute to the formation of halonitromethanes. These results can be used to control the formation of N-DBPs in the disinfection of low SUVA waters.