The objective of this manuscript was to assess the toxicity formation on biological treated wastewater from a municipal wastewater treatment plant, after a chlorination-dechlorination disinfection process. Water was monitored by means of physicochemical and ecotoxicological parameters, with the use of Vibrio fischeri bioassay. Since a dechlorination process removed residual chlorine, the positi...

The occurrences of trihalomethanes (THMs), haloacetic acids (HAAs) and heterotrophic bacteria were monitored in five small water systems over a nine-month period to investigate the association between HAA degradation and heterotrophic bacteria populations. The sampling sites were chosen to cover the entire distribution network for each system. An inverse association between heterotrophic bacter...

OBJECTIVE To introduce a new sequential chlorination disinfection process in which short-term free chlorine and chloramine are sequentially added. METHODS Pilot tests of this sequential chlorination were carried out in a drinking water plant. RESULTS The sequential chlorination disinfection process had the same or better efficiency on microbe (including virus) inactivation compared with the...

Disinfection of produce is principally used to inactivate spoilage microbes and may also reduce the risk of consumer exposure to enteric pathogens. However, the rate and extent of enteric virus inactivation by free chlorine on produce has not been adequately characterized. Experiments were performed to determine the kinetics of free chlorine inactivation of hepatitis A virus (HAV) and the indic...

fungi are found in different environments with variable distribution patterns depending on various factors. the aim of this study was determination of fungal contaminants in public swimming pools in uromia, iran. the fungal contaminations of four indoor swimming pools were studied by using membrane filtration and swab sampling method. samples were collected by a manual plastic pump, in a 200 ml...

Free chlorine has been used extensively as a primary and secondary disinfectant for potable water. Where it is difficult to maintain a free chlorine residual or when disinfection by-products (DBPs) are of concern, monochloramine has been used to provide a stable disinfectant residual in distributions systems. Reactions of disinfectants, free chlorine or monochloramine, with natural organic matt...

Point-of-use (POU) water treatment with sodium hypochlorite (NaOCl) has been proven to reduce diarrheal disease in developing countries. However, program implementation is complicated by unclear free chlorine residual guidelines for POU water treatment and difficulties in determining appropriate dosage recommendations. The author presents evidence supporting proposed criteria for household wate...

Inhalation of potable water presents a potential route of exposure to opportunistic pathogens and hence warrants significant public health concern. This study used qPCR to detect opportunistic pathogens Legionella spp., L. pneumophila and MAC at multiple points along two potable water distribution pipelines. One used chlorine disinfection and the other chloramine disinfection. Samples were coll...

The aim of this study was to investigate the effects of the use of chlorine or ozone as sanitizing agents in the water of chicken immersion chilling, using the residual levels usually applied in Brazil (1.5 ppm), comparing the effects of these treatments on the microbiological, physicochemical, and sensory characteristics of carcasses. Chicken carcasses were chilled in water (4°C) with similar ...