Cristóbal Chaidez1, Juan R Ibarra-Rodríguez2, José Benigno Valdez-Torres1, Marcela Soto3, Charles P Gerba4, Nohelia Castro-Del Campo5. 1. Laboratory of Environmental and Food Microbiology, Centro de Investigación en Alimentación y Desarrollo, A.C., Unidad Culiacán, Sinaloa, México (Drs Chaidez, Valdez-Torres, and Castro-del Campo). 2. Consejo Nacional de Ciencia y Tecnología-Centro de Investigación en Alimentación y Desarrollo, A.C. (Dr. Ibarra-Rodríguez). 3. Facultad de Ciencias Químico-Biológicas, Universidad Autónoma de Sinaloa, Ciudad Universitaria, Culiacán, Sinaloa, México (Dr Soto). 4. Soil, Water and Environmental Science Department, University of Arizona, Tucson, Arizona (Dr Gerba). 5. Laboratory of Environmental and Food Microbiology, Centro de Investigación en Alimentación y Desarrollo, A.C., Unidad Culiacán, Sinaloa, México (Drs Chaidez, Valdez-Torres, and Castro-del Campo). Electronic address: ncastro@ciad.mx.
Abstract
OBJECTIVE: In developing countries, rural communities often face the lack of potable water infrastructure and must rely on untreated sources for drinking, which are often contaminated with waterborne pathogens. The use of home water treatment devices is seen as one means of reducing the risk of exposure to waterborne pathogens. The aim of this study was to evaluate the microbiological and physicochemical performance of a simple in-home point-of-use device based on gravity ultrafiltration through an ultrafilter membrane. METHODS: Twenty-five randomly selected households from 2 rural communities in Culiacán, Mexico, were enrolled. Water samples were collected before and after treatment and during storage for a period of 8 weeks. Heterotrophic bacteria, total coliforms, fecal coliforms, Escherichia coli, and Giardia spp were quantified, as well as various physicochemical parameters. RESULTS: All of the untreated water samples contained high levels of indicator bacteria, but none were detected in the treated water fulfilling the requirements set by the Mexican Norm (NOM-127-SSA1-1994) and the World Health Organization guidelines for drinking water. However, indicator bacteria (fecal coliforms and E coli) were detected in every sample from water stored 24 hours after treatment. CONCLUSION: This study demonstrated that point-of-use filters using gravity-fed ultrafilters are a low-cost, effective water treatment technology for water of poor microbial quality. However, further identification of the sources and mechanisms by which water is contaminated when stored after treatment will help with designing and implementing better strategies for keeping water safe for domestic use.
OBJECTIVE: In developing countries, rural communities often face the lack of potable water infrastructure and must rely on untreated sources for drinking, which are often contaminated with waterborne pathogens. The use of home water treatment devices is seen as one means of reducing the risk of exposure to waterborne pathogens. The aim of this study was to evaluate the microbiological and physicochemical performance of a simple in-home point-of-use device based on gravity ultrafiltration through an ultrafilter membrane. METHODS: Twenty-five randomly selected households from 2 rural communities in Culiacán, Mexico, were enrolled. Water samples were collected before and after treatment and during storage for a period of 8 weeks. Heterotrophic bacteria, total coliforms, fecal coliforms, Escherichia coli, and Giardia spp were quantified, as well as various physicochemical parameters. RESULTS: All of the untreated water samples contained high levels of indicator bacteria, but none were detected in the treated water fulfilling the requirements set by the Mexican Norm (NOM-127-SSA1-1994) and the World Health Organization guidelines for drinking water. However, indicator bacteria (fecal coliforms and E coli) were detected in every sample from water stored 24 hours after treatment. CONCLUSION: This study demonstrated that point-of-use filters using gravity-fed ultrafilters are a low-cost, effective water treatment technology for water of poor microbial quality. However, further identification of the sources and mechanisms by which water is contaminated when stored after treatment will help with designing and implementing better strategies for keeping water safe for domestic use.
Authors: Nur Hidayati Othman; Nur Hashimah Alias; Nurul Syazana Fuzil; Fauziah Marpani; Munawar Zaman Shahruddin; Chun Ming Chew; Kam Meng David Ng; Woei Jye Lau; Ahmad Fauzi Ismail Journal: Membranes (Basel) Date: 2021-12-27