Characterisation of the biosand filter for E. coli reductions from household drinking water under controlled laboratory and field use conditions

2006 ◽  
Vol 54 (3) ◽  
pp. 1-7 ◽  
Author(s):  
C.E. Stauber ◽  
M.A. Elliott ◽  
F. Koksal ◽  
G.M. Ortiz ◽  
F.A. DiGiano ◽  
...  

More than a billion people in the developing world lack access to safe and reliable sources of drinking water. Point of use (POU) household water treatment technology allows people to improve the quality of their water by treating it in the home. One emerging POU technology is the biosand filter (BSF), a household-scale, intermittently operated slow sand filter. Laboratory and field studies examined Escherichia coli reductions achieved by the BSF. During two laboratory studies, mean E. coli reductions were 94% and they improved over the period of filter use, reaching a maximum of 99%. Field analysis conducted on 55 household filters near Bonao, Dominican Republic averaged E. coli reductions of 93%. E. coli reductions by the BSF in laboratory and field studies were less than those typically observed for traditional slow sand filters (SSFs), although as for SSFs microbial reductions improved over the period of filter use. Further study is needed to determine the factors contributing to microbial reductions in BSFs and why reductions are lower than those of conventional SSFs.

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1094
Author(s):  
Emily S. Bailey ◽  
Nikki Beetsch ◽  
Douglas A. Wait ◽  
Hemali H. Oza ◽  
Nirmala Ronnie ◽  
...  

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.


2018 ◽  
Vol 13 (1) ◽  
pp. 60
Author(s):  
Nurul Ismillayli ◽  
Laili Mardiana ◽  
Rina Kurnianingsih ◽  
Dhony Hermanto ◽  
Fahrurazi Fahrurazi

Penerapan teknologi tepat guna tentang proses pengolahan air siap minum dengan menggunakan metode filtrasi, adsorpsi dan reverse osmosis telah dilakukan. Rancangan alat  pengelolaan air siap minum menggunakan kombinasi filtrasi-adsorpsi meliputi saringan pasir lambat (terdiri dari pasir silika, arang aktif, ijuk, kapas, dan kerikil) membran selulosa, granula karbon, karbon aktif, membran RO (reverse osmosis), dan lampu ultraviolet untuk desinfikasi. Penentuan beberapa parameter fisik (bau, warna), kimia (pH, Fe, nitrit, amonia, BOD5, COD, DO) dan biologi (bakteri E-coli) dari sumber air (irigasi) dan air hasil pemurnian dilakukan di Laboratorium Kimia Universitas Mataram dan Balai Laboratorium Kesehatan Pengujian dan Kalibrasi Provinsi NTB. Air siap minum yang dihasilkan memiliki kualitas sesuai dengan baku mutu air minum Peraturan Menteri Kesehatan Nomor 492/Menkes/Per/IV/2010 Tanggal 19 April 2010. Hasil uji organoleptik menunjukkan bahwa masyarakat menyukai air hasil pengolahan dan merespon positif terhadap alih teknologi pengolahan air. Pembangunan sentra pengelohan air siap minum diharapkan menjadi edukasi bagi masyarakat mengenai perilaku hidup bersih dan sehat. Implementation of appropriate technology on the process of potable water using filtration, adsorption and reverse osmosis methods has been done. Its design used a combination of filtration-adsorption includes slow sand filters (consisting of silica sand, activated charcoal, palm fiber, cotton, and gravel) cellulosic membranes, carbon granules, activated carbon, RO (reverse osmosis) membranes, and ultraviolet for disinfection. Determination of several physical (odor, color), chemical (pH, Fe, nitrite, ammonia, BOD5, COD, DO) and biological parameters (E-coli) of purified water were conducted at Chemical Laboratory of Mataram University and Health Laboratory Testing and Calibration Center of West Nusa Tenggara Province. The potable water produced has quality according to the quality standard of drinking water Regulation of the Minister of Health No. 492/Menkes/Per/IV/2010 Date April 19, 2010. The organoleptic test showed that the community responds positively to the knowledge transfer of water treatment technology. The construction of potable water center is expected to educate the public about clean and healthy living behaviorKata kunci: filtrasi, adsorpsi, reverse osmosis, air sungai, air siap minum


2017 ◽  
Vol 16 (1) ◽  
pp. 112-125 ◽  
Author(s):  
Natalie Wilhelm ◽  
Anya Kaufmann ◽  
Elizabeth Blanton ◽  
Daniele Lantagne

Abstract Household water treatment with chlorine can improve the microbiological quality of household water and reduce diarrheal disease. We conducted laboratory and field studies to inform chlorine dosage recommendations. In the laboratory, reactors of varying turbidity (10–300 NTU) and total organic carbon (0–25 mg/L addition) were created, spiked with Escherichia coli, and dosed with 3.75 mg/L sodium hypochlorite. All reactors had >4 log reduction of E. coli 24 hours after chlorine addition. In the field, we tested 158 sources in 22 countries for chlorine demand. A 1.88 mg/L dosage for water from improved sources of <5 or <10 NTU turbidity met free chlorine residual criteria (≤2.0 mg/L at 1 hour, ≥0.2 mg/L at 24 hours) 91–94% and 82–87% of the time at 8 and 24 hours, respectively. In unimproved water source samples, a 3.75 mg/L dosage met relaxed criteria (≤4.0 mg/L at 1 hour, ≥0.2 mg/L after 24 hours) 83% and 65% of the time after 8 and 24 hours, respectively. We recommend water from improved/low turbidity sources be dosed at 1.88 mg/L and used within 24 hours, and from unimproved/higher turbidity sources be dosed at 3.75 mg/L and consumed within 8 hours. Further research on field effectiveness of chlorination is recommended.


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2302
Author(s):  
Daniela A. Duran Romero ◽  
Maria Cristina de Almeida Silva ◽  
Beni J. M. Chaúque ◽  
Antônio D. Benetti

The number of people living without access to clean water can be reduced by the implementation of point-of-use (POU) water treatment. Among POU treatment systems, the domestic biosand filter (BSF) stands out as a viable technology. However, the performance of the BSF varies with the inflow water quality characteristics, especially turbidity. In some locations, people have no choice but to treat raw water that has turbidity above recommended levels for the technology. This study aimed to measure the efficiency with which the BSF removes microorganisms from well water and from fecal-contaminated water with turbidity levels of 3, 25, and 50 NTU. Turbidity was controlled by the addition of kaolin to water. Turbidity removal varied from 88% to 99%. Reductions in total coliform (TC) and Escherichia coli ranged from 0.54–2.01 and 1.2–2.2 log removal values (LRV), respectively. The BSF that received water with a higher level of turbidity showed the greatest reduction in the concentration of microorganisms. Additional testing with water contaminated with four bacterial pure cultures showed reductions between 2.7 and 3.6 LRV. A higher reduction in microorganisms was achieved after 30–35 days in operation. Despite the filter’s high efficiency, the filtrates still had some microorganisms, and a disinfection POU treatment could be added to increase water safety.


Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 872
Author(s):  
Resoketswe Charlotte Moropeng ◽  
Maggy Ndombo Benteke Momba

The current study investigated the acceptance rate and long-term effectiveness of cost-effective household water treatment systems deployed in Makwane Village. A structured questionnaire was used prior to implementation to collect information such as level of education, level of employment, and knowledge about point-of-use water treatment systems in the target area. The long-term effectiveness was determined by factors such as the Escherichia coli removal efficiency, turbidity reduction, silver leached, and flow rate of the household water treatment devices. The results of the survey prior to deployment revealed that only 4.3% of the community had a tertiary qualification. Moreover, 54.3% of the community were unemployed. The results further revealed that 65.9% of the community were knowledgeable about other point-of-use water treatment methods. The acceptance rate, which was found to be initially higher (100%), reduced after three months of implantation (biosand filter with zeolite-silver clay granular—82.9%; silver-impregnated porous pot filters—97.1%). Moreover, the long-term effectiveness was determined, taking into consideration the adoption rate, and it was found that silver-impregnated porous pot filters have a long life compared to biosand filter with zeolite-silver clay granular. Although household water treatment systems can effectively reduce the burden of waterborne diseases in impoverished communities, the success of adoption is dependent on the targeted group. This study highlights the significance of involving community members when making the decision to scale up household water treatment devices in rural areas for successful adoption.


2015 ◽  
Vol 3 (4) ◽  
pp. 343-353
Author(s):  
Jonathan N. Hogarh ◽  
Fatai A. Sowunmi ◽  
Agbola P. Oluwafemi ◽  
Philip Antwi-Agyei ◽  
Daniel Nukpezah ◽  
...  

2006 ◽  
Vol 1 (2) ◽  
Author(s):  
Stephen W. Gundry ◽  
James A. Wright ◽  
Ronan Conroy ◽  
Martella Du Preez ◽  
Bettina Genthe ◽  
...  

Aims: To assess contamination of drinking water in rural Zimbabwe and South Africa Methods: We conducted a cohort study of 254 children aged 12-24 months in rural South Africa and Zimbabwe. In dry and wet seasons, we measured water quality, using the indicator organism E. coli, at improved and unimproved sources, in household storage and drinking cups. We also recorded hygiene and socio-economic factors for each household. Results: For improved sources, samples with E. coli counts less than 10 cfu/100ml were as follows: at source: 165 (88%); in household storage 137 (59%); in drinking cups 91 (49%). The corresponding values for unimproved sources were: source 47 (29%); household storage 32 (19%); drinking cups 21 (18%). This significant deterioration in microbial quality of water from improved sources was seen in both countries and both survey rounds. Conclusion: Although improved sources generally delivered ‘safe’ water at the point-of-supply, 12% of source samples were contaminated and as such were ‘unsafe’. Furthermore, in household storage, more than 40% of samples were ‘unsafe’. For monitoring the Millennium Development Goal for water, UNICEF-WHO are assuming an equivalence between ‘improved’ sources and ‘safe’ water. Our findings suggest that this equivalence may be unsound.


2017 ◽  
Vol 23 (2) ◽  
pp. 150-167 ◽  
Author(s):  
Morgan Callender MacDonald ◽  
Luke Juran ◽  
Sekar Srinivasan ◽  
Jincy Jose ◽  
Syed Imran Ali ◽  
...  

Field studies on household water treatment and safe storage (HWTS) suggest that positive health outcomes are strongly linked to user compliance. We investigated factors that influenced compliance in a marginalized community of South India where residents worked with researchers to develop a water treatment intervention in absence of government water utilities. Survey and water quality data were collected during a 12-month randomized controlled trial of 124 households. Data were used to construct indices for social, technical, and institutional predictors of compliance including technological effectiveness, gender, community capacity, perceived benefit, and inherent demand. Perceived benefit was the only parameter to be significantly associated with compliance. Households in which participants had “very high” levels of perceived benefit were over 4 times more likely to comply with instructions on water treatment and maintenance with the HWTS. These findings suggest that compliance, and therefore disease prevention, can be improved by enhancing perceived benefit to the user.


2011 ◽  
Vol 1 (2) ◽  
pp. 102-111 ◽  
Author(s):  
Amanda R. Kaufman ◽  
Lisa M. Casanova ◽  
Mark D. Sobsey

Treatment of drinking water at the point of use (POU) has demonstrated health benefits for people who have access only to microbially contaminated drinking water. In this work, the ceramic siphon POU water filter was evaluated for its ability to reduce indicator microorganisms in test waters. During batch challenge tests, the filter reduced Escherichia coli in filtered water by 7 log10 (99.999987%) and bacteriophage MS2 by 0.12 log10 (24.0%). Next, a novel continuous flow dosing system allowing sewage-amended feed water to constantly pass through the filters allowed for determination of changes in microbial reductions over time and total volume of water filtered. E. coli B, MS2 and fluorescent microspheres (as a surrogate for Cryptosporidium oocysts) were seeded into test water and dosed to filters at 10, 25 and 50% of the filter's volume lifespan. Microbial removal efficacy decreased as the volume of water filtered increased and test filters did not achieve their volume lifespan before physically failing. The ceramic siphon household water filter is effective in reducing E. coli and surrogates for Cryptosporidium in water, but filter modifications may be needed to achieve acceptable levels of virus removal and to reach the target 7,000 L volume lifespan of the filter.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gillian E. Clayton ◽  
Robin M. S. Thorn ◽  
Darren M. Reynolds

AbstractChlorine solutions are used extensively for the production of biologically safe drinking water. The capability of point-of-use [POU] drinking water treatment systems has gained interest in locations where centralised treatment systems and distribution networks are not practical. This study investigated the antimicrobial and anti-biofilm activity of three chlorine-based disinfectants (hypochlorite ions [OCl-], hypochlorous acid [HOCl] and electrochemically activated solutions [ECAS]) for use in POU drinking water applications. The relative antimicrobial activity was compared within bactericidal suspension assays (BS EN 1040 and BS EN 1276) using Escherichia coli. The anti-biofilm activity was compared utilising established sessile Pseudomonas aeruginosa within a Centre for Disease Control [CDC] biofilm reactor. HOCl exhibited the greatest antimicrobial activity against planktonic E. coli at >50 mg L−1 free chlorine, in the presence of organic loading (bovine serum albumen). However, ECAS exhibited significantly greater anti-biofilm activity compared to OCl- and HOCl against P. aeruginosa biofilms at ≥50 mg L−1 free chlorine. Based on this evidence disinfectants where HOCl is the dominant chlorine species (HOCl and ECAS) would be appropriate alternative chlorine-based disinfectants for POU drinking water applications.


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