Data were gathered on the presence of disinfection by-products (DBPs) in drinking water and picrin (CHP); chloral hydrate (CH); on the impact of treatment processes on DBP formation and control. Thirty-five water cyanogen chloride (CNCI); 2,4,6-trichlotreatment facilities were selected to provide a broad range of source water qualities and rophenol; formaldehyde; and acetaldetreatment processes. Trihalomethanes were the largest class of DBPs detected (on a weight hyde (Figure 1). This article focuses on basis) in this study, with haloacetic acids being the next most significant DBP fraction. some of the significant preliminary Formaldehyde and acetaldehyde, by-products of ozonation, were also demonstrated to be findings of these DBP studies. produced by chlorination. Cyanogen chloride was found to be preferentially produced in Experimental procedures chloraminaied water.The sampling and analytical proceof this project, baseline data were gath-dures utilized in these studies are deered on all 35 water utilities.
Little information regarding the effectiveness of UV radiation on the inactivation of caliciviruses and enteric adenoviruses is available. Analysis of human calicivirus resistance to disinfectants is hampered by the lack of animal or cell culture methods that can determine the viruses' infectivity. The inactivation kinetics of enteric adenovirus type 40 (AD40), coliphage MS-2, and feline calicivirus (FCV), closely related to the human caliciviruses based on nucleic acid organization and capsid architecture, were determined after exposure to low-pressure UV radiation in buffered demand-free (BDF) water at room temperature. In addition, UV disinfection experiments were also carried out in treated groundwater with FCV and AD40. AD40 was more resistant than either FCV or coliphage MS-2 in both BDF water and groundwater. The doses of UV required to achieve 99% inactivation of AD40, coliphage MS-2, and FCV in BDF water were 109, 55, and 16 mJ/cm 2 , respectively. The doses of UV required to achieve 99% inactivation of AD40, coliphage MS-2, and FCV in groundwater were slightly lower than those in BDF water. FCV was inactivated by 99% by 13 mJ/cm 2 in treated groundwater. A dose of 103 mJ/cm 2 was required for 99% inactivation of AD40 in treated groundwater. The results of this study indicate that if FCV is an adequate surrogate for human caliciviruses, then their inactivation by UV radiation is similar to those of other single-stranded RNA enteric viruses, such as poliovirus. In addition, AD40 appears to be more resistant to UV disinfection than previously reported.
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.