he proposed Disinfectants/Disinfection By-products (D/DBP) Rule and the Enhanced Surface Water Treatment Rule (ESWTR) have prompted an industrywide evaluation of disinfection and treatment practices.1,2 One of the least expensive methods of limiting DBP formation is to use monochloramine instead of free chlorine to maintain a distribution system residual. Monochloramine limits free chlorine con...

Background and aims: The main cause of many problems in developing countries is related to the provision of safe drinking water. Since the health of drinking water is important in the busy centers such as hospitals, clinics and health centers, this study was done to investigate the role of water coolers connected to the municipal system in microbial quality of drinking water in...

SYSTEMATIC INVESTIGATION of low and erratic results obtained in one laboratory on standard solutions of uric acid revealed the presence of considerable free residual chlorine in the supply of distilled water. A further study was made of the effect of free chlorine on the determination of uric acid and other substances susceptible to oxidation-reduction reactions. Collier and Stuart (1) previous...

We describe a glucuronidase bioassay for detecting residual bactericidal activity from the use of disinfectants on hard surfaces; in this assay we used formaldehyde, ethanol, isopropanol, chlorine, and a commercial preparation containing 2-bromo-2-nitro-1, 3-propanediol. Chlorine and the commercial preparation showed bactericidal activity (53.5% and 98.2%, respectively) for a week after disinfe...

This study investigated a small subset of the two community water-disinfection systems--hypochlorinators and tablet feeders-in rural Honduras. Levels of residual chlorine were assessed at three locations within the distribution system: the tank, the proximal house, and the distal house. The levels of residual chlorine were compared with the standard guidelines set by the Pan American Health Org...

Chlorine is widely used in public water supplies to provide a disinfection barrier. The effect of chlorine disinfection on the water-borne pathogen Burkholderia pseudomallei was assessed using multiple techniques. After exposure to chlorine viable bacteria were undetectable by conventional plate count techniques; however, persistence of B. pseudomallei was verified by flow cytometry and bacteri...

Poliovirus in fecal homogenates was used to determine the protection against inactivation by chlorination afforded virus that was occluded within particulates. Virus that was closely associated with or occluded within small fecal particulates was protected. A fourfold increase in combined residual chlorine was required to achieve the same degree of inactivation for occluded virus as for free or...

Environmental surfaces contaminated with pathogens can be sources of indirect transmission, and cleaning and disinfection are common interventions focused on reducing contamination levels. We determined the efficacy of cleaning and disinfection procedures for reducing contamination by noroviruses, rotavirus, poliovirus, parechovirus, adenovirus, influenza virus, Staphylococcus aureus, and Salmo...

We examined the in vitro bactericidal effects and efficacy on handwashing of water containing electrolytic products of sodium chloride (electrolytic water). The electrolytic water, whose pH and concentration of free residual chlorine were 6.7-6.9 and 20-22 ppm, respectively, showed equal reduction of both Staphylococcus aureus and Escherichia coli to dilution of commercially available sodium hy...