scholarly journals Field trial of an automated batch chlorinator system at shared water points in an urban community of Dhaka, Bangladesh

2016 ◽  
Vol 6 (1) ◽  
pp. 32-41 ◽  
Author(s):  
Nuhu Amin ◽  
Yoshika S. Crider ◽  
Leanne Unicomb ◽  
Kishor K. Das ◽  
Partha Sarathi Gope ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Low Income ◽  
Technology Development ◽  
User Preferences ◽  
Intermittent Flow ◽  
Small Scale ◽  
E Coli ◽  
Point Of Use ◽  
Colony Forming Units

Point-of-use water treatment with chlorine is underutilized in low-income households. The Zimba, an automated batch chlorinator, requires no electricity or moving parts, and can be installed at shared water points with intermittent flow. We conducted a small-scale trial to assess the acceptability and quality of Zimba-treated municipal water. Fieldworkers collected stored drinking water over a 10-week period from control (n = 24 households) and treatment (n = 30 households) compounds to assess levels of free chlorine and E. coli contamination. Overall, 80% of stored drinking water samples had a safe chlorine residual among treatment households, compared to 29% among control households (P < 0.001). Concentrations of E. coli were lower (mean difference = 0.4 log colony-forming units/100 mL, P = 0.004) in treatment compared to control households. Fifty-three percent of mothers (n = 17), thought the Zimba was easy to use and 76% were satisfied with the taste. The majority of mothers mentioned that collecting water from the Zimba took more time and created a long queue at the handpump. The Zimba successfully chlorinated household stored drinking water; however, further technology development is required to address user preferences. The Zimba may be a good option for point-of-collection water treatment in areas where queuing for water is uncommon.

scholarly journals Decentralized solar-powered drinking water ozonation in Western Kenya: an evaluation of disinfection efficacy

2020 ◽  
Vol 4 ◽  
pp. 56
Author(s):  
Colin Hendrickson ◽  
Jared Oremo ◽  
Oscar Oluoch Akello ◽  
Simon Bunde ◽  
Isaac Rayola ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Surface Water ◽  
Drinking Water Treatment ◽  
Treatment System ◽  
Coliform Bacteria ◽  
Small Scale ◽  
Water Treatment System ◽  
E Coli ◽  
Solar Powered

 Background: Decentralized drinking water treatment methods generally apply membrane-based treatment approaches. Ozonation of drinking water, which previously has only been possible at large centralized facilities, can now be accomplished on a small-scale using microplasma technology. The efficacy of decentralized solar-powered drinking water treatment systems has not previously been described. Methods: We established a 1,000L decentralized solar-powered water treatment system located in Kisumu County, Kenya. Highly contaminated surface water is pumped to the treatment system, which includes flocculation and filtration steps prior to ozonation. Turbidity, total coliform bacteria, and E. coli were measured at various stages of water treatment, and bacterial log reduction values (LRVs) were calculated. Results: Forty-seven trials were conducted in which1000L of water were flocculated, filtered, and ozonated for 180 minutes. Baseline turbidity and E. coli concentrations were reduced from a median of 238 nephelometric turbidity units (NTU) and 2,419.7 most probable number/100mL, respectively, in surface water to 1.0 NTU and undetectable E. coli after ozonation for 180 minutes. The median E. coli LRV was 3.99. Conclusions: The solar-powered, decentralized water treatment system that utilizes ozonation for disinfection was founded to reduce E. coli by more than 3 log-orders of magnitude despite the high turbidity of the raw water. Further research is needed to characterize limitations, scalability, economic viability, and community perspectives that could help determine the role for similar systems in other settings.

Bacteriological quality of drinking water at point of use and hand hygiene of primary food preparers: implications for household food safety

2016 ◽  
Vol 6 (2) ◽  
pp. 224-230
Author(s):  
S. G. D. N. Lakshmi Reddi ◽  
R. Naveen Kumar ◽  
G. M. SubbaRao ◽  
M. Vishnu Vardhana Rao ◽  
R. V. Sudershan
Keyword(s):  
Drinking Water ◽  
Food Safety ◽  
Hand Hygiene ◽  
Low Income ◽  
Water Samples ◽  
Faecal Coliforms ◽  
E Coli ◽  
Point Of Use ◽  
Drinking Water Samples

Quality of water for consumption and food processing activities is universally accepted as an essential component to ensure food safety at household (HH) level. Along with safe water, hand hygiene is also an important factor for reducing diarrheal illnesses. This was a cross-sectional study conducted in rural and urban HHs to detect hygiene indicators in drinking water samples at point of use (PoU) (n = 150) and their association with the hand hygiene of primary food preparers (n = 150). Overall, 24.7% and 9.3% of drinking water samples (PoU), 48% and 20% of hand rinse samples were contaminated by faecal coliforms and E. coli, respectively. Both drinking water (PoU) and hand rinse samples collected from rural HHs showed higher contamination, followed by those from urban slums and low income HHs. Significant association (p < 0.05) and probable risk with faecal coliforms (OR. 2.5; 95% CI: 1.1–5.4) and E. coli (OR. 14.5; 95% CI: 4.1–50.7) was found between hand rinses and drinking water samples that had bacteriological contamination. These results suggest that there was an extensive cross contamination at HH level. So, targeted education is essential on safe food/water handling practices in HHs to prevent food safety risks.

scholarly journals Decentralized solar-powered drinking water ozonation in Western Kenya: an evaluation of disinfection efficacy

2020 ◽  
Vol 4 ◽  
pp. 56
Author(s):  
Colin Hendrickson ◽  
Jared Oremo ◽  
Oscar Oluoch Akello ◽  
Simon Bunde ◽  
Isaac Rayola ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Surface Water ◽  
Drinking Water Treatment ◽  
Treatment System ◽  
Coliform Bacteria ◽  
Small Scale ◽  
Probable Number ◽  
E Coli ◽  
Solar Powered

Background: Decentralized drinking water treatment methods generally apply membrane-based treatment approaches. Ozonation of drinking water, which previously has only been possible at large centralized facilities, can now be accomplished on a small-scale using microplasma technology. The efficacy of decentralized solar-powered ozonation for drinking water treatment is not known. Methods: We established a 1,000L decentralized solar-powered water treatment system located in Kisumu County, Kenya. Highly contaminated surface water is pumped to the treatment system, which includes flocculation and filtration steps prior to ozonation. Turbidity, total coliform bacteria, and E. coli were measured at various stages of water treatment, and bacterial log reduction values (LRVs) were calculated. Results: Nine trials were conducted treating 1000L of water in three hours. Baseline turbidity and E. coli concentrations were reduced from a median of 238 nephelometric turbidity units (NTU) and 2,752 most probable number/100mL, respectively, in surface water to 1.0 NTU and undetectable E. coli per100mL in finished drinking water. The nine trials yielded a mean E. coli LRV of 3.36 (2.71-4.00, 95% CI). Conclusions: Based on the observed reduction of E. coli, the solar-powered system shows promise as a means for producing safe drinking water. Further research is needed to characterize limitations, scalability, economic viability, and community perspectives that could help determine the role for similar systems in other settings.

scholarly journals Solar Powered Microplasma-Generated Ozone: Assessment of a Novel Point-of-Use Drinking Water Treatment Method

2020 ◽  
Vol 17 (6) ◽  
pp. 1858 ◽  
Author(s):  
Samuel Dorevitch ◽  
Kendall Anderson ◽  
Abhilasha Shrestha ◽  
Dorothy Wright ◽  
Aloyce Odhiambo ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
System Optimization ◽  
Treatment Method ◽  
Probable Number ◽  
Western Kenya ◽  
E Coli ◽  
Point Of Use ◽  
Solar Powered

Ozonation is widely used in high-income countries for water disinfection in centralized treatment facilities. New microplasma technology has reduced the energy requirements for ozone generation dramatically, such that a 15-watt solar panel is sufficient to produce small quantities of ozone. This technology has not been used previously for point-of-use drinking water treatment. We conducted a series of assessments of this technology, both in the laboratory and in homes of residents of a village in western Kenya, to estimate system efficacy and to determine if the solar-powered point-of-use water ozonation system appears safe and acceptable to end-users. In the laboratory, two hours of point-of-use ozonation reduced E. coli in 120 L of wastewater by a mean (standard deviation) of 2.3 (0.84) log-orders of magnitude and F+ coliphage by 1.54 (0.72). Based on laboratory efficacy, 10 families in Western Kenya used the system to treat 20 L of household stored water for two hours on a daily basis for eight weeks. Household stored water E. coli concentrations of >1000 most probable number (MPN)/100 mL were reduced by 1.56 (0.96) log removal value (LRV). No participants experienced symptoms of respiratory or mucous membrane irritation. Focus group research indicated that families who used the system for eight weeks had very favorable perceptions of the system, in part because it allowed them to charge mobile phones. Drinking water ozonation using microplasma technology may be a sustainable point-of-use treatment method, although system optimization and evaluations in other settings would be needed.

Antibacterial silver-diatomite nanocomposite ceramic with low silver release

2019 ◽  
Vol 20 (2) ◽  
pp. 633-643
Author(s):  
Xiaopeng Qi ◽  
Junwei Chen ◽  
Qian Li ◽  
Hui Yang ◽  
Honghui Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Water Treatment ◽  
Photoelectron Spectroscopy ◽  
Bactericidal Effect ◽  
Ceramic Filter ◽  
Ceramic Filters ◽  
X Ray ◽  
E Coli ◽  
Point Of Use ◽  
Silver Release

Abstract There is an urgent need for an effective and long-lasting ceramic filter for point-of-use water treatment. In this study, silver-diatomite nanocomposite ceramic filters were developed by an easy and effective method. The ceramic filters have a three-dimensional interconnected pore structure and porosity of 50.85%. Characterizations of the silver-diatomite nanocomposite ceramic filters were performed using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Silver nanoparticles were confirmed to be formed in situ in the ceramic filter. The highest silver concentration in water was 0.24 μg/L and 2.1 μg/L in short- and long-term experiments, indicating very low silver-release properties of silver-diatomite nanocomposite ceramic filter. The nanocomposite ceramics show strong bactericidal activity. When contact time with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) of 105 colony forming units (CFU)/mL exceeded 3 h, the bactericidal rates of the four different silver content ceramics against E. coli and S. aureus were all 100%. Strong bactericidal effect against E. coli with initial concentration of 109 CFU/mL were also observed in ceramic newly obtained and ceramic immersed in water for 270 days, demonstrating its high stability. The silver-diatomite nanocomposite ceramic filters could be a promising candidate for point-of-use water treatment.

scholarly journals Methods, Protocols, Guidance and Standards for Performance Evaluation for Point-of-Use Water Treatment Technologies: History, Current Status, Future Needs and Directions

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1094
Author(s):  
Emily S. Bailey ◽  
Nikki Beetsch ◽  
Douglas A. Wait ◽  
Hemali H. Oza ◽  
Nirmala Ronnie ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Enteric Bacteria ◽  
Current Status ◽  
Household Water Treatment ◽  
Produce Water ◽  
Point Of Use ◽  
Treatment Technologies ◽  
Injury And Repair ◽  
Testing Protocols

It is estimated that 780 million people do not have access to improved drinking water sources and approximately 2 billion people use fecally contaminated drinking water. Effective point-of-use water treatment systems (POU) can provide water with sufficiently reduced concentrations of pathogenic enteric microorganisms to not pose significant health risks to consumers. Household water treatment (HWT) systems utilize various technologies that physically remove and/or inactivate pathogens. A limited number of governmental and other institutional entities have developed testing protocols to evaluate the performance of POU water treatment systems. Such testing protocols are essential to documenting effective performance because inferior and ineffective POU treatment technologies are thought to be in widespread use. This critical review examines specific practices, procedures and specification of widely available POU system evaluation protocols. Testing protocols should provide standardized and detailed instructions yet be sufficiently flexible to deal with different treatment technologies, test microbe priorities and choices, testing facility capabilities and public health needs. Appropriate infectivity or culture assays should be used to quantify test enteric bacteria, viruses and protozoan parasites, or other appropriate surrogates or substitutes for them, although processes based on physical removal can be tested by methods that detect microbes as particles. Recommendations include further research of stock microbe production and handling methods to consistently yield test microbes in a realistic state of aggregation and, in the case of bacteria, appropriately physiologically stressed. Bacterial quantification methods should address the phenomenon of bacterial injury and repair in order to maximally recover those that are culturable and potentially infectious. It is only with harmonized national and international testing protocols and performance targets that independent and unbiased testing can be done to assure consumers that POU treatment technologies are able to produce water of high microbial quality and low health risk.

Experiences with the practical implementation and operation of biological nitrification for a small-scale drinking water treatment plant

2016 ◽  
Vol 16 (4) ◽  
pp. 922-930 ◽  
Author(s):  
L. Richard ◽  
E. Mayr ◽  
M. Zunabovic ◽  
R. Allabashi ◽  
R. Perfler
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Water Supply ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Drinking Water Supply ◽  
Small Scale ◽  
Treatment Performance ◽  
Biological Nitrification

The implementation and evaluation of biological nitrification as a possible treatment option for the small-scale drinking water supply of a rural Upper Austrian community was investigated. The drinking water supply of this community (average system input volume: 20 m3/d) is based on the use of deep anaerobic groundwater with a high ammonium content of geogenic origin (up to 5 mg/l) which must be treated to prevent the formation of nitrites in the drinking water supply system. This paper describes the implementation and operation of biological nitrification despite several constraints including space availability, location and financial and manpower resources. A pilot drinking water treatment plant, including biological nitrification implemented in sand filters, was designed and constructed for a maximum treatment capacity of 1.2 m3/h. Online monitoring of selected physicochemical parameters has provided continuous treatment performance data. Treatment performance of the plant was evaluated under standard operation as well as in the case of selected malfunction events.

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