In water industry, the chlorine is mostly used as a disinfectant agent. The chlorine present in potable water as a disinfectant has been reported to reduce the lifetime of contact polymeric material. This occurs in po...In water industry, the chlorine is mostly used as a disinfectant agent. The chlorine present in potable water as a disinfectant has been reported to reduce the lifetime of contact polymeric material. This occurs in polymer pipes and it is now very common in plumbing and other parts of the drinking water distribution system. For more than 50 years, Polymer & Elastomeric materials have been used ubiquitously in drinking water distribution systems. Polymer & Elastomeric materials have successfully been used in a variety of applications ranging from rubber gaskets, to valves, to hydrants, to fittings. Polymer & Elastomers that degrade more quickly than expected create service problems, make it difficult for utilities to cost efficient plan preventive maintenance programs, and negatively affect customer relations. This review paper gives an insight idea to a reader about the selection of proper polymer & elastomer and predicting its performance in chlorinated water. Also the mechanism of degradation of Polymer & elastomer in chlorine environment and some model of life expectancy of in-service of Polymer & elastomer in various conditions and parameter in chlorinated water were discussed.展开更多
Background:Diarrheal disease is a leading cause of child mortality and morbidity worldwide.Household water treatment with chlorine significantly reduces morbidity due to waterborne diseases.However,the effect of point...Background:Diarrheal disease is a leading cause of child mortality and morbidity worldwide.Household water treatment with chlorine significantly reduces morbidity due to waterborne diseases.However,the effect of point-ofuse(POU)water treatment in improving the quality of water in areas where POU is not provided free of charge and the effectiveness of home visits in inspiring household members to use POU regularly have not been studied.The objective of this study was to evaluate the effectiveness of drinking water disinfection by chlorination on diarrheal disease reduction among children under the age of 5 years in rural eastern Ethiopia.Methods:A cluster randomized controlled trial was carried out in rural Dire Dawa from October 2018 through January 2019.The 405 households were randomized to intervention and control arms and intervention materials were distributed after conducting a baseline survey.This trial evaluated the effectiveness of household drinking water disinfection by chlorination in reducing incidence of diarrhea among children under the age of 5 years.Intervention households received 1.2%sodium hypochlorite with demonstration of its proper use.Participants in the control households continued with their usual habits of water collection and water storage.Generalized estimation equations(GEE)with log link Poisson distribution family and exchangeable correlation matrix was used to compute crude incidence rate ratio(IRR),adjusted IRR and the corresponding 95%confidence intervals.Results:In the intervention households,in total,281 cases of diarrhea were documented(8.7 cases per 100 personweeks observation);in the control households,in total 446 cases of diarrhea were documented(13.8 cases per 100 person-weeks observation).A 36.0%(adjusted IRR=0.64,95%CI:0.57–0.73)reduction in incidence of diarrhea was observed in the intervention arm when compared with the control arm.The highest and the lowest reductions were obtained in children of age ranges 1 to 2 years and 3 to 4 years,42.7 and 30.4%,respectively.Adherence to the intervention was 81.3%as measured by free residual chlorine test.Conclusions:In rural areas where diarrhea is the second leading cause of morbidity,water chlorination at the household level using liquid bleach considerably reduced episodes of diarrhea among children under the age of 5 years.Therefore,chlorinating drinking water at the household level may be a valuable interim solution for reducing the incidence of diarrheal diseases until potable water is made accessible to the majority of the population in Dire Dawa Administration and other Ethiopian communities.展开更多
文摘In water industry, the chlorine is mostly used as a disinfectant agent. The chlorine present in potable water as a disinfectant has been reported to reduce the lifetime of contact polymeric material. This occurs in polymer pipes and it is now very common in plumbing and other parts of the drinking water distribution system. For more than 50 years, Polymer & Elastomeric materials have been used ubiquitously in drinking water distribution systems. Polymer & Elastomeric materials have successfully been used in a variety of applications ranging from rubber gaskets, to valves, to hydrants, to fittings. Polymer & Elastomers that degrade more quickly than expected create service problems, make it difficult for utilities to cost efficient plan preventive maintenance programs, and negatively affect customer relations. This review paper gives an insight idea to a reader about the selection of proper polymer & elastomer and predicting its performance in chlorinated water. Also the mechanism of degradation of Polymer & elastomer in chlorine environment and some model of life expectancy of in-service of Polymer & elastomer in various conditions and parameter in chlorinated water were discussed.
文摘Background:Diarrheal disease is a leading cause of child mortality and morbidity worldwide.Household water treatment with chlorine significantly reduces morbidity due to waterborne diseases.However,the effect of point-ofuse(POU)water treatment in improving the quality of water in areas where POU is not provided free of charge and the effectiveness of home visits in inspiring household members to use POU regularly have not been studied.The objective of this study was to evaluate the effectiveness of drinking water disinfection by chlorination on diarrheal disease reduction among children under the age of 5 years in rural eastern Ethiopia.Methods:A cluster randomized controlled trial was carried out in rural Dire Dawa from October 2018 through January 2019.The 405 households were randomized to intervention and control arms and intervention materials were distributed after conducting a baseline survey.This trial evaluated the effectiveness of household drinking water disinfection by chlorination in reducing incidence of diarrhea among children under the age of 5 years.Intervention households received 1.2%sodium hypochlorite with demonstration of its proper use.Participants in the control households continued with their usual habits of water collection and water storage.Generalized estimation equations(GEE)with log link Poisson distribution family and exchangeable correlation matrix was used to compute crude incidence rate ratio(IRR),adjusted IRR and the corresponding 95%confidence intervals.Results:In the intervention households,in total,281 cases of diarrhea were documented(8.7 cases per 100 personweeks observation);in the control households,in total 446 cases of diarrhea were documented(13.8 cases per 100 person-weeks observation).A 36.0%(adjusted IRR=0.64,95%CI:0.57–0.73)reduction in incidence of diarrhea was observed in the intervention arm when compared with the control arm.The highest and the lowest reductions were obtained in children of age ranges 1 to 2 years and 3 to 4 years,42.7 and 30.4%,respectively.Adherence to the intervention was 81.3%as measured by free residual chlorine test.Conclusions:In rural areas where diarrhea is the second leading cause of morbidity,water chlorination at the household level using liquid bleach considerably reduced episodes of diarrhea among children under the age of 5 years.Therefore,chlorinating drinking water at the household level may be a valuable interim solution for reducing the incidence of diarrheal diseases until potable water is made accessible to the majority of the population in Dire Dawa Administration and other Ethiopian communities.
