The formation of disinfection by-products (DBPs) from chlorination and monochloramination of treated drinking waters was determined. Samples were collected after treatment at 11 water treatment works but before exposure to chlorine or monochloramine. Formation potential tests were carried out to determine the DBPs formed by chlorination and monochloramination. DBPs measured were trihalomethanes (THMs), haloacetic acids (HAAs), halonitromethanes (HNMs), haloacetonitriles (HANs), haloaldehydes (HAs), haloketones (HKs) and iodo-THMs (i-THMs). All waters had the potential to form significant levels of all the DBPs measured. Compared to chlorine, monochloramination generally resulted in lower concentrations of DBPs with the exception of 1,1-dichloropropanone. The concentrations of THMs correlated well with the HAAs formed. The impact of bromine on the speciation of the DBPs was determined. The literature findings that higher bromide levels lead to higher concentrations of brominated DBPS were confirmed.
Parameters (pH, bromide, and temperature) affecting the formation of trihalomethanes (THMs) and haloacetic acids (HAAs) were investigated by chlorinating two geographically different waters in the UK: lowland and upland water. It was expected that THM levels would increase as pH increased whereas HAA levels would decrease with an increase in pH. The lowland water reacted as expected to changes in pH but the upland water did not. The greatest impact of pH was observed in the formation of THMs in the lowland water. The difference in natural organic matter (NOM) structure may account for such differences. Concentration of bromide had a greater impact in the upland water. Reducing the temperature from 20°C to 7°C resulted in a mean decrease of DBP concentration by 50%.Natural organic matter (NOM) is described as an intricate mixture of organic compounds that occurs universally in ground and surface waters. Whilst NOM itself is not problematic, it can be converted to disinfection by-products (DBPs) when disinfectants are used during water treatment (7). In the UK, regulated DBPs include trihalomethanes (THMs -chloroform, bromoform,
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.