Degradation of Disinfection Byproducts in Drinking Water

Abstract

An investigation of the behavior of different categories of disinfection byproducts (DBPs) in ultrapure water and in spiked drinking water samples was performed. The influence of sunlight, pH, and time was examined. Several of the compounds were subject to degradation with time, while others showed increasing trends, possibly due to natural production by bacteria. Chloroform, monochloroacetonitrile, and monochloroacetic acid slightly increased in the presence of sunlight, while dichloroacetonitrile, dibromoacetic acid, tribromoacetic acid, and mixed bromo-chloro acetic acids were subject to decomposition, especially under sunlight. However, sunlight was found to decelerate decomposition of trichloropropanone and to prevent decomposition of bromochloro-acetonitrile and chloral hydrate. Trichloropropanone decomposed to chloroform, while mixed haloacetic acids decomposed to the corresponding trihalomethanes. Multiple regression equations were obtained for the concentrations of individual DBPs in drinking water as a function of time, pH, and sunlight. Most of the volatile DBPs decreased with increasing pH both in sunlight and in darkness, while haloacetic acids remained unaffected from pH. However, haloacetic acids seemed to be influenced by sunlight to a significantly greater extent than volatile DBPs. Knowledge of the behavior of individual compounds during exposure to sunlight is essential towards the development of photolysis-based removal techniques. pH influence needs to be considered, especially in the case of volatile DBPs.

What’s in the Pool? A Comprehensive Identification of Disinfection By-products and Assessment of Mutagenicity of Chlorinated and Brominated Swimming Pool Water

“…Consequently, this study expands considerably our knowledge of the chemical composition and mutagenicity of swimming pool water beyond the chemical analysis of two outdoor pools by Zwiener et al (2007) and the studies on pool water mutagenicity ( Honer et al 1980 ) and genotoxicity ( Glauner et al 2005 ; Liviac et al 2010 ). We found a greater number of DBPs in the chlorinated and brominated indoor pools studied here than have been found in chlorinated outdoor pools ( Zwiener et al 2007 ), which was not surprising, considering that DBPs can be volatilized or photolyzed ( Lekkas and Nikolaou 2004 ) in outdoor settings. In addition, although most people assume that chlorine levels in swimming pools are much higher than in chlorinated drinking water, the mean level of free chlorine (1.28 and 0.50 mg/L in the chlorinated and brominated pools, respectively) was similar to that found typically in drinking water.…”

Photolytic removal of DBPs by medium pressure UV in swimming pool water

“…2 and can be seen in Table 1. According to these values, the presence of bromine in the molecular structure of THM remarkably increased the removal rate, since these species are more photosensitive than their chlorinated analogues (Chen et al, 2010;De Laat and Berne 2009;Lekkas and Nikolaou 2004). Therefore, the kinetic constant corresponding to bromoform (0.390 min -1 ) was the highest and chloroform (0.020 min -1 ) the lowest.…”

The Behaviour of Haloacetic Acids in Distribution Zones in Scotland

“…DCAA has been classified as a group B 2 chemical (i.e., a probable human carcinogen) by the Integrated Risk Information System of the United States Environmental Protection Agency (U.S. EPA) and TCAA as a group C compound (possible human carcinogen) [18]. Furthermore, both of these compounds have been proven to be animal carcinogens [19]. The formation, control, and health effects of HAAs, THMs and other disinfection byproducts (DBPs) in drinking water are issues of international concern and a significant amount of research on them has been conducted in the last decades.…”