Jnl Health Pop Nutr, Dec 2011
Storing Drinking-water in Copper-pots Kills Contaminating Diarrhoeagenic Bacteria
V.B. Preethi Sudha et al.
Microbially-unsafe water is still a major concern in most developing countries. Although many water-purification methods exist, these are expensive and beyond the reach of many people, especially in rural areas. Ayurveda recommends the use of copper for storing drinking-water. Therefore, the objective of this study was to evaluate the effect of copper-pot on microbially-contaminated drinking-water. The antibacterial effect of copper-pot against important diarrhoeagenic bacteria, including Vibrio cholerae O1, Shigella flexneri 2a, enterotoxigenic Escherichia coli, enteropathogenic E. coli, Salmonella enterica Typhi, and Salmonella Paratyphi is reported. When drinking-water (pH 7.83±0.4; source: ground) was contaminated with 500 CFU/mL of the above bacteria and stored in copper-pots for 16 hours at room temperature, no bacteria could be recovered on the culture medium.
This is the first report on the effect of copper on S. flexneri 2a, enteropathogenic E. coli, and Salmonella Paratyphi. After 16 hours, there was a slight increase in the pH of water from 7.83 to 7.93 in the copper-pots while the other physicochemical parameters remained unchanged. Copper content (177±16 ppb) in water stored in copper-pots was well within the permissible limits of the World Health Organization. Copper holds promise as a point-of-use solution for microbial purification of drinking-water, especially in developing countries.
International Journal of Water Resources and Environmental Engineering Vol. 3(14), pp. 385-392, 21 December, 2011
A study of solar disinfection for rural water supply
Olatunde Ayoola Ajayi, et al.
Drinking water available to rural communities in many developing countries contains disease germs. Solar disinfection of water is becoming increasingly appreciated because of the feasibility of its application. This study investigated the level of transmission of ultraviolet light by bottles made of glass, poly vinyl chloride (PVC) and polyethlene terephthalate (PET) in relation to their ability to disinfect water samples in them; two brands of PET bottles, Ragolis and Voltic, were used. Ragolis bottle was the best both in ultraviolet light transmission and microbial inactivation. There was no microbial re-growth during 11 weeks storage of solar–treated water. Rural dwellers in Nigeria have easy access to large quantities of used PET bottles and can use the 1.5 L size to produce solar-disinfected water for drinking.
Environ Sci Technol. 2011 Dec 20.
Cluster Randomized Controlled Trial of the Plastic BioSand Water Filter in Cambodia.
Stauber CE, Printy ER, McCarty FA, Liang KR, Sobsey MD.
Institute of Public Health, Georgia State University , P.O. Box 3995, Atlanta, Georgia 30302-3995, United States.
About half of the rural population of Cambodia lacks access to improved water; an even higher percentage lacks access to latrines. More than 35,000 concrete BioSand Water filters (BSF) have been installed in the country. However, the concrete BSF takes time to produce and weighs hundreds of pounds. A plastic BSF has been developed but may not perform to the same benchmarks established by its predecessor. To evaluate plastic BSF performance and health impact, we performed a cluster randomized controlled trial in 13 communities including 189 households and 1147 participants in the Angk Snoul district of Kandal Province from May to December 2008.
The results suggest that villages with plastic BSFs had significantly lower concentrations of E. coli in drinking water and lower diarrheal disease (incidence rate ratio 0.41, 95% confidence interval: 0.24-0.69) compared to control villages. As one of the first studies on the plastic BSF in Cambodia, these are important findings, especially in a setting where the concrete BSF has seen high rates of continued use years after installation. The study suggests the plastic BSF may play an important role in scaling up the distribution/implementation of the BSF, potentially improving water quality and health in the region.
Journal of Water and Health Vol 9 No 4 2011
Away-from-home drinking water consumption practices and the microbiological quality of water consumed in rural western Kenya
W. Onyango-Ouma and Charles P. GerbaInstitute of Anthropology, Gender and African Studies, University of Nairobi, PO Box 30197, Nairobi, 00100, Kenya
Department of Soil, Water and Environmental Science, University of Arizona, Tucson, AZ 85721, USA E-mail: gerba@ag.arizona.edu
A cross-sectional descriptive study was conducted to examine away-from-home drinking water consumption practices and the microbiological quality of water consumed in rural western Kenya. The study involved adults and schoolchildren. Data were collected using focus group discussions, questionnaire survey, observations, diaries and interviews. The findings suggest that away-from-home drinking water consumption is a common practice in the study area; however, the microbiological quality of the water consumed is poor.
While some respondents perceive the water to be safe for drinking mainly because of the clear colour of the water, others are forced by circumstances to drink the water as it is owing to a lack of alternative safe sources. It is concluded that there is a need for new innovative approaches to address away-from-home drinking water consumption in resource-poor settings in order to complement and maximize the benefits of point-of-use water treatment at the household level.
Risk Anal. 2012 Jan;32(1):67-80.
Risk Management in a Developing Country Context: Improving Decisions About Point-of-Use Water Treatment Among the Rural Poor in Africa.
Arvai J, Post K.
Haskayne School of Business, and the Institute for Sustainable Energy, Environment, and Economy, University of Calgary, 440 Scurfield Hall, Calgary, Alberta, Canada. Decision Research, 1201 Oak Street, Eugene, OR 97401, USA. Center for the Advanced Study of International Development, Michigan State University, 305 Natural Resources Building, East Lansing, MI 48824, USA.
More than 1 billion people, the vast majority of which live in the developing world, lack basic access to clean water for domestic use. For this reason, finding and promoting effective and sustainable solutions for the provision of reliable clean water in developing nations has become a focus of several public health and international development efforts. Even though several means of providing centrally located sources of clean water in developing communities exist, the severity and widespread nature of the water problem has led most development agencies and sanitation experts to strongly advocate the use of point-of-use treatment systems alongside whatever source of water people regularly use.
In doing so, however, development practitioners have been careful to point out that any interventions or infrastructure regarding water safety and human health must also adhere to one of the central principles of international development: to facilitate more democratic and participatory models of decision making and governance. To this end, the research reported here focused on the development of a deliberative risk management framework for involving affected stakeholders in decisions about POU water treatment systems. This research, which was grounded in previous studies of structured decision making, took place in two rural villages in the East African nation of Tanzania.
Public-Private Partnership Model for Point-of-Use Water Disinfection among Lower Income Households: A demonstration project In Uttar Pradesh, India. October 2010. Washington, DC: Point-of-Use Water Disinfection and Zinc Treatment (POUZN) Project.
This report focuses on the POU program in India, which was launched in 2006 and was initially envisioned as just a year-long demonstration. USAID field supportcontinued through September 2010, and activities eventually reached four million people. The program was carried out in Uttar Pradesh (UP), India’s poorest state, with a population of 180 million and among the country’s highest rates of childhood mortality.
The goal of POUZN in India was to demonstrate a comprehensive strategy addressing barriers related to awareness, acceptance, availability, and affordability of POU water treatment methods in order to increase their use among poor urban and rural populations and thereby reduce childhood diarrhea. The at-scale goal was to achieve 30 percent rural and 40 percent urban use of an effective POU method.
Plastic bags for water treatment : a new approach to solar disinfection of drinking water, 2011.
Pierik, Bradley, Thesis, University of British Columbia
In remote regions plastic bottles are often unavailable, or are prohibitively expensive. For this reason there exists a need for an alternative to plastic bottles for SODIS use in remote regions of the world. In this study, real and artificial sunlight exposures, standard microbiological enumeration methods, and tensile strength and optical transmittance measurement methods, were used to evaluate whether a plastic SODIS bag is a potential alternative to SODIS bottles. SODIS bags were found to yield as much as 74% higher treatment efficiencies than SODIS bottles, which may be because the bags were able to reach the elevated temperatures that are shown to cause accelerated treatment. The physical wear of hanging SODIS was approximately half the rate (47%) of SODIS bags’ wear and this suggests that hanging SODIS bags may have a longer useful life. A curve relating water depth and the efficiency of the water treatment process in SODIS bags under certain representative treatment conditions was generated and used to predict the optimal geometry of SODIS bags. Additionally, a new method was proposed for calculating the solar UV dose, which may be more appropriate than conventional methods. These findings suggest that SODIS bags may be an appropriate alternative to SODIS bottles. The findings further provide information to guide the design and implementation of SODIS bags.
Environ Sci Technol. 2011 Dec 15.
Virus removal in ceramic depth filters based on diatomaceous earth.
Michen B, Meder F, Rust A, Fritsch J, Aneziris C, Graule T.
Ceramic filter candles, based on the natural material diatomaceous earth (DE), are widely used to purify water at the point-of-use (POU). Although such depth filters are known to improve drinking water quality by removing human pathogenic protozoa and bacteria, their removal regarding viruses has been rarely investigated. These filters have relatively large pore diameters compared to the physical dimension of viruses. However, viruses may be retained by adsorption mechanisms due to intermolecular and surface forces.
Here, we use three types of bacteriophages to investigate their removal during filtration and batch experiments conducted at different pH values and ionic strengths. Theoretical models based on DLVO-theory are applied in order to verify experimental results and assess surface forces involved in the adsorptive process. This was done by calculation of interaction energies between the filter surface and the viruses. For two small spherically-shaped viruses (MS2 and PhiX174) these filters showed no significant removal. In the case of phage PhiX174, where attractive interactions were expected, due to electrostatic attraction of oppositely charged surfaces, only little adsorption was reported in the presence of divalent ions.
Thus, we postulate the existence of an additional repulsive force between PhiX174 and the filter surface. It is hypothesized that such an additional energy barrier originates from either the phage’s specific knobs that protrude from the viral capsid, enabling steric interactions, or hydration forces between the two hydrophilic interfaces of virus and filter. On the other hand, a larger-sized, tailed bacteriophage of the family Siphoviridae was removed by 2 to 3 log which is explained by postulating hydrophobic interactions.
Int. J. Environ. Res. Public Health 2012, 9(1), 139-170; doi:10.3390/ijerph9010139
Removal of Escherichia coli and Faecal Coliforms from Surface Water and Groundwater by Household Water Treatment Devices/Systems: A Sustainable Solution for Improving Water Quality in Rural Communities of the Southern African Development Community Region
Jocelyne K. Mwabi
There is significant evidence that household water treatment devices/systems (HWTS) are capable of dramatically improving microbially contaminated water quality. The purpose of this study was to examine five filters [(biosand filter-standard (BSF-S); biosand filter-zeolite (BSF-Z); bucket filter (BF); ceramic candle filter (CCF); and silver-impregnated porous pot (SIPP)] and evaluate their ability to improve the quality of drinking water at the household level. These HWTS were manufactured in the workshop of the Tshwane University of Technology and evaluated for efficiency to remove turbidity, faecal coliforms and Escherichia coli from multiple water source samples, using standard methods.
The flow rates ranged from 0.05 L/h to 2.49 L/h for SIPP, 1 L/h to 4 L/h for CCF, 0.81 L/h to 6.84 L/h for BSF-S, 1.74 L/h to 19.2 L/h and 106.5 L/h to 160.5 L/h for BF The turbidity of the raw water samples ranged between 2.17 and 40.4 NTU. The average turbidity obtained after filtration ranged from 0.6 to 8 NTU (BSF-S), 1 to 4 NTU (BSF-Z), 2 to 11 NTU (BF), and from 0.6 to 7 NTU (CCF) and 0.7 to 1 NTU for SIPP. The BSF-S, BSF-Z and CCF removed 2 to 4 log10 (99% to 100%) of coliform bacteria, while the BF removed 1 to 3 log (90% to 99.9%) of these bacteria.
The performance of the SIPP in removing turbidity and indicator bacteria (>5 log10, 100%) was significantly higher compared to that of the other HWTS (p < 0.05). The findings of this study indicate that the SIPP can be an effective and sustainable HWTS for the Southern African Development Community (SADC) rural communities, as it removed the total concentration of bacteria from test water, can be manufactured using locally available materials, and is easy to operate and to maintain.
Drinking Water Equity, Safety and Sustainability: Thematic report on drinking water, 2011.
UNICEF, WHO.
The primary purpose of the report is to investigate access to and use of drinking water in greater detail than is possible in the regular JMP progress reports. The report includes multiple disaggregation of water service levels and analyses of trends across countries and regions. These illustrate in detail how people access drinking water and what changes have occurred since 1990. The report focuses on the three key challenges of equity, safety and sustainability. Disparities in terms of geography, wealth and gender are explored, which highlight the need to target water service delivery towards specific populations.
Water safety concerns are highlighted and the scope of household water treatment is investigated. The challenges involved in sustaining water services and ensuring reliable supplies, in both rural and urban contexts, are also explored, including the unique threats posed by climate change.
