Solar Disinfection – an Appropriate Water Treatment Method to Inactivate Faecal Bacteria in Cold Climates

Abstract - Project design and implementation of water treatment technologies in the developing world often overlooks potential pitfalls because: 1) technical experts focus on technologies without considering cultural acceptability and 2) projects lack monitoring, evaluation, and project revision. Over the past five years, Engineers Without Borders (EWB) at the UC-Davis partnered with the Rural Agency for Sustainable Development (RASD) in Nkokonjeru, Uganda, to implement sustainable point of use (POU) water systems. POU systems (i.e. Filtron clay pot filters, solar disinfection, chlorine treatment, and colloidal silver) were tested and implemented at RASD’s training center in Nkokonjeru. While all of the systems effectively removed pathogens, cultural appropriateness and education were the most important drivers of project acceptance. After a one-year assessment, it was determined that community preference was driven by transparency of treatment method, cost, stigma, and ease of use. Clay pot filters were preferred because of ease of use and physical particle removal capabilities. However, high cost, lack of local production and transportation difficulties dictated that their use was not sustainable. Biosand filters were introduced as an alternative and although originally deemed to be too complicated, they have been accepted by the community and continue to be manufactured by RASD in Nkokonjeru.

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The effectiveness of solar disinfection water treatment method for reducing childhood diarrhea: a systematic review and meta-analysis protocol

Systematic Reviews ◽

10.1186/s13643-020-01288-8 ◽

2020 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Negasa Eshete Soboksa ◽

Sirak Robele Gari ◽

Abebe Beyene Hailu ◽

Dereje Oljira Donacho ◽

Bezatu Mengistie Alemu

Keyword(s):

Systematic Review ◽

Water Treatment ◽

Meta Analysis ◽

Treatment Method ◽

Childhood Diarrhea ◽

Solar Disinfection ◽

Analysis Protocol

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Effectiveness of solar disinfection water treatment method for reducing childhood diarrhoea: a systematic review and meta-analysis

BMJ Open ◽

10.1136/bmjopen-2020-038255 ◽

2020 ◽

Vol 10 (12) ◽

pp. e038255

Author(s):

Negasa Eshete Soboksa ◽

Sirak Robele Gari ◽

Abebe Beyene Hailu ◽

Dereje Oljira Donacho ◽

Bezatu Mengistie Alemu

Keyword(s):

Systematic Review ◽

Water Treatment ◽

Meta Analysis ◽

Intervention Group ◽

Treatment Method ◽

Cochrane Library ◽

Control Group ◽

Solar Disinfection ◽

Childhood Diarrhoea ◽

Registration Number

ObjectiveThis study aimed to pool out the available evidence on the effectiveness of the solar disinfection water treatment method for reducing childhood diarrhoea.DesignSystematic review and meta-analysis.SettingGlobal.MethodsSearches were conducted in Medline/PubMed, Scopus, Google Scholar, Cochrane Library databases and references to other studies. The review included all children living anywhere in the world regardless of sex, ethnicity and socioeconomic status published in English until December 2019. Studies that compared the diarrhoea incidence between the intervention group who were exposed to solar disinfection water treatment and the control group who were not exposed to such water treatment were included. The outcome of interest was the change in observed diarrhoea incidence and the risk from baseline to postintervention. Two independent reviewers critically appraised the selected studies. Effect sizes were expressed as risk ratios, and their 95% CIs were calculated for analysis.ResultsWe identified 10 eligible studies conducted in Africa, Latin America and Asia that included 5795 children aged from 1 to 15 years. In all identified studies, solar disinfection reduced the risk of diarrhoea in children, and the effect was statistically significant in eight of the studies. The estimated pooled risk ratio of childhood diarrhoea among participants that used the solar disinfection water treatment method was 0.62 (95% CI 0.53 to 0.72). The overall pooled results indicated that the intervention of solar disinfection water treatment had reduced the risk of childhood diarrhoea by 38%.ConclusionsThe intervention of solar disinfection water treatment significantly reduced the risk of childhood diarrhoea. However, the risk of bias and marked heterogeneity of the included studies precluded definitive conclusions. Further high-quality studies are needed to determine whether solar disinfection water treatment is an important method to reduce childhood diarrhoea.PROSPERO registration numberCRD42020159243

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The Vyredox and Nitredox Methods of in situ Treatment of Groundwater

Water Science & Technology ◽

10.2166/wst.1988.0093 ◽

1988 ◽

Vol 20 (3) ◽

pp. 149-163 ◽

Cited By ~ 30

Author(s):

Carol Braester ◽

Rudolf Martinell

Keyword(s):

Water Treatment ◽

Surface Water ◽

Traditional Method ◽

Treatment Method ◽

Nitrate Treatment ◽

The Past ◽

The World ◽

Nitrate And Nitrite ◽

Iron And Manganese

Nearly one fifth of all water used in the world is obtained from groundwater. The protection of water has become a high priority goal. During the last decades pollution of water has become more and more severe. Today groundwater is more and more used in comparison with surface water. Recently we have seen accidents, which can pollute nearly all surface water very quickly. Generally the groundwater is easier to protect, as well as cheaper to purify, and above all it is of better quality than the surface water. During the past two decades, alternatives to the traditional method of treating the water in filters have been developed, that is in situ water treatment i.e. the VYREDOX and NITREDOX methods. The most common problem regarding groundwater is too high content of iron and manganese, which can be reduced with the VYREDOX method. In some areas today there are severe problems with pollution by hydrocarbons and nitrate as well, and with modification of the VYREDOX treatment method it is used for hydrocarbon and nitrate treatment as well. The method to reduce the nitrate and nitrite is known as the NITREDOX method.

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Use of a stable carbon isotope to assess the efficiency of a drinking water treatment method with CO2

Water Science & Technology ◽

10.2166/wst.2012.008 ◽

2012 ◽

Vol 65 (6) ◽

pp. 983-988 ◽

Cited By ~ 1

Author(s):

M. Poberžnik ◽

A. Leis ◽

A. Lobnik

Keyword(s):

Drinking Water ◽

Water Treatment ◽

Dissolved Inorganic Carbon ◽

Tap Water ◽

Stable Carbon Isotope ◽

Research Work ◽

Drinking Water Treatment ◽

Treatment Method ◽

Water Supply Systems ◽

Co2 Gas

CO2 gas with a special isotopic signature (δ13C = −35.2‰ vs. VPDB) was used as a marker to evaluate the efficiency of a drinking water treatment method and the effect of an ultrasonic (US) stirrer. This treatment was developed to prevent precipitation and corrosion effects in water–supply systems. The research work was performed using a laboratory-scale pilot plant that was filled with tap water. The stable isotope analyses of δ13C-DIC (Dissolved Inorganic Carbon) in the water samples indicated that the maximum content of added CO2 gas in DIC was in the range of 35 to 45%. The use of the US stirrer during the entire experiment decreased the method's overall efficiency by 10%, due to degassing at a late stage of the experiment but accelerated the dissolution process in the early experimental stage.

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Nanomaterials Based Drinking Water Purification: Comparative Study with a Conventional Water Purification Process

Periodica Polytechnica Chemical Engineering ◽

10.3311/ppch.12458 ◽

2018 ◽

Vol 63 (1) ◽

pp. 96-112 ◽

Cited By ~ 1

Author(s):

Barış Şimşek ◽

İnci Sevgili ◽

Özge Bildi Ceran ◽

Haluk Korucu ◽

Osman Nuri Şara

Keyword(s):

Silver Nanoparticles ◽

Drinking Water ◽

Graphene Oxide ◽

Water Treatment ◽

Water Purification ◽

Drinking Water Treatment ◽

Treatment Method ◽

Salmonella Typhi ◽

Liquid Ratio ◽

Solid Liquid

One of the ways of fully securing the presence of fresh water is water treatment process. Nanomaterials and nanotechnology offers an innovative solution for water treatment. In this study, physical, chemical and microbiological improvement rates of raw water were analyzed after filtration with graphene oxide. Graphene oxide's water treatment performance; silver nanoparticles, silver nanoparticles & graphene oxide composites that are commonly used in water treatment were compared with a traditional treatment method. When compared to the traditional method, there were improvements of 50 %, 40.7 %, 86.8 % and 45.5 % for color, TIC, TOC and hardness properties, respectively in water treatment by GO-based filtration with solid liquid ratio of 0.7 % (v/v). In water treatment with GO-Ag based filtration, 39.8 %, 69.8 %, 10.3 % and 28.6 % of improvements were obtained for TIC, TOC, hardness and LSI value compared to the conventional method. Both GO at 0.7 % (v/v) solid-liquid ratio and GO-Ag nanocomposites were successful in the number of total viable microorganisms and inhibiting microorganisms such as Escherichia coli fecal (gaita-infected), Salmonella typhi, Enterococcus faecalis, Pseudomona aeruginosa and Staphylococcus aureus. Among the studied parameters GO-Ag nanocomposites found to be the most suitable for drinking water treatment.

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Zinc Oxide Nanostructures Synthesized by a Simple Hot Water Treatment Method for Photocatalytic Degradation of Organic Pollutants in Water

MRS Advances ◽

10.1557/adv.2020.290 ◽

2020 ◽

pp. 1-9

Author(s):

Ranjitha Kumarapuram Hariharalakshmanan ◽

Nawzat S. Saadi ◽

Busra Ergul-Yilmaz ◽

Khalidah H. Al – Mayalee ◽

Tansel Karabacak

Keyword(s):

Water Treatment ◽

Uv Light ◽

Treatment Method ◽

Zinc Powder ◽

Hot Water ◽

Hot Water Treatment ◽

Zno Nanostructures ◽

Zno Nanostructure ◽

Oxide Nanostructures ◽

Metal Oxide Nanostructures

Abstract The use of zinc oxide (ZnO) nanostructures as a photocatalyst for the degradation of organic pollutants in water has received significant attention over the recent years. However, synthesis methods for producing ZnO nanostructures are generally costly, complicated, and hazardous to the environment. In this work, we demonstrate the synthesis of ZnO nanostructures by a simple hot water treatment (HWT) method and the photocatalytic activity of the hence produced nanostructures. HWT is a one-step, low-cost, eco-friendly, and scalable nanostructure growth method. By HWT, various metal-oxide nanostructures can be produced simply by the interaction of metals with hot water without the need for any chemical additives in the solution. Growth of metal-oxide nanostructures by HWT involves the formation of metal-oxides and their release from the surface of the metal into water, the migration of the metal-oxides in water, and their re-deposition at a different part of the metallic surface, which initiates the growth of nanostructures. In this study, we used zinc powder and plates for producing the ZnO nanostructures by HWT in DI water at 75°C. Scanning electron microscopy and X-ray diffraction were utilized to verify the formation of ZnO nanostructures. Zinc plates produced a suspension of ZnO nanostructures in water, while on the other hand, zinc powder resulted in ZnO nanostructures grown on the powder surface as well as standalone ZnO nanostructures also mixed in water. We used these nanostructures + water suspensions for our photocatalytic degradation studies. Methylene blue (MB) was used as a model organic pollutant. We mixed the ZnO nanostructure suspension with MB and exposed it to UV light. The degradation of MB was observed by measuring its absorbance values using a UV-Visible spectrophotometer over a period of 4 hours. We observed a 20% decrease in the concentration of MB in 4 hours when nanostructured Zn/ZnO powder suspension was used, and a 30% decrease was achieved when ZnO nanostructure-only suspension produced from zinc plates was used. MB alone was also exposed to UV light for the same period as a control experiment, and we did not observe any significant decrease in its concentration. These results indicate that the hot water treatment method presents a very simple, cost-effective, scalable, and eco–friendly alternative for the synthesis of ZnO nanostructures for photocatalytic water treatment applications.

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