Microbial and chemical assessment of ceramic and BioSand water filters in rural Cambodia

2010 ◽  
Vol 10 (3) ◽  
pp. 286-295 ◽  
Author(s):  
H. M. Murphy ◽  
M. Sampson ◽  
K. Farahbakhsh ◽  
E. McBean

Unless significant advances are made in the water and sanitation sector, it is unlikely that Cambodia will meet the United Nations Millennium Development Goal (MDG) target #7 for water and sanitation. Point-of-use technologies (POU), also termed “household water treatment technologies”, have been identified as successful options for providing safe water to rural households. Ceramic water filters and BioSand filters are two major POU technologies that are currently implemented across Cambodia. This paper presents data on the microbial performance of these two technologies in the field on various Cambodian source waters. In addition, data are presented on the occurrence of nitrite in treated water. Results showed that 61% and 88% of BioSand filters and ceramic filters, respectively, produced water in the low risk range for E. coli as defined by the WHO (0–10 CFU/100 mL). In addition, 83% of BioSand filters and 75% of ceramic filters were not meeting the WHO guideline value for chronic exposure to nitrite in drinking water (0.2 mg/L).

2018 ◽  
Vol 6 (3) ◽  
Author(s):  
Ed McBean ◽  
Aili Yang ◽  
Huiyan Cheng ◽  
YiCheng Wu ◽  
Zheng Liu ◽  
...  

‘Geo-hazards’ is a collective term to describe hazards causing huge problems with human settlements, where the hazards are many and varied, including earthquakes, floods, windstorms, and drought, all of which are intensifying over time in large part due to climate change and population growth.  In particular, issues of availability of ‘safe’ water are major disruptive elements frequently causing widespread incidence of diarrheal diseases both during and post, geo-hazard events. In response, arguments are described which demonstrate ceramic water filters (CWFs) have credible potential to effectively remove E.-coli (and, by similar attribute characterization), are effective in the removal of cholera. Field experience in terms of removal have been demonstrated as 94.7% removal of E-coli and all users in some applications have expressed interest in continuing use of ceramic filters beyond the trial period. Arguments are put forth, for CWFs as a Point-of-Use (POU) technology by which they can be stored and rapidly disseminated given occurrence of geo-hazards, thereby providing the opportunity to respond quickly. CWFs can be effectively stored without deterioration, are inexpensive, and easy to train recipients for their post-geo-hazard occurrence.


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.


2013 ◽  
Vol 14 (2) ◽  
pp. 304-311 ◽  
Author(s):  
Cameron Farrow ◽  
Edward McBean ◽  
Hamidreza Salsali

Ceramic water filters (CWFs) are utilized in many developing countries as point-of-use (POU) water treatment devices, to reduce waterborne pathogens in potable water. Virus removal efficiencies of several CWFs are investigated under various influent conditions using MS2 (ATCC: 15597-B1) as a surrogate phage for human enteric viruses. The addition of bentonite turbidity (6–8 NTU) in the influent source water showed increased viral removal efficiency of CWFs by 0.1–0.2 log compared to tests involving clear (<1 NTU) influents. Trials employing an applied clay cake layer, formed using highly turbid influent source water (100 NTU) and no cleaning regime between trials, resulted in viral removal efficiency values of 1.5–2.5 log, compared to 0.2–0.5 log during non-obstructed trials.


2019 ◽  
Vol 9 (4) ◽  
pp. 694-702 ◽  
Author(s):  
Laura Guerrero-Latorre ◽  
Priscila Balseca-Enriquez ◽  
Carlos Moyota-Tello ◽  
Ronald Bravo-Camino ◽  
Stephanie Davila-Chavez ◽  
...  

Abstract In rural Ecuador, microbial water contamination is associated with child morbidity mainly due to gastroenteritis. Black ceramic water filters (BCWF) are a new household water treatment recently developed to improve microbial removal from the classical model implemented worldwide. This study has assessed BCWF microbial performance at laboratory level by continuous filtering of spiked water with microbial surrogates (Escherichia coli and MS2 bacteriophage) and highly contaminated surface water to evaluate physicochemical pollutants' removal. At field level, baseline studies in Nanegal and Gualea districts have been performed to evaluate water quality and hygiene practices among communities and a six-month BCWF field implementation study in the Santa Marianita community. Results revealed poor drinking water quality in communities studied. Water treatment practices at household level were reported in low percentages. Conversely, results in BCWF filter assays at laboratory level for 600 litres of usage have shown 5.36 logarithms of bacterial removal and 3.83 logarithms for viral removal and significant reductions of physicochemical pollutants considering international standards. BCWF implementation in the Santa Marianita community reveals promising results on microbial water quality in households using this new technology. However, it is important to reinforce correct BCWF maintenance for better performance at field level.


2016 ◽  
Vol 6 (2) ◽  
pp. 195-204 ◽  
Author(s):  
Ansley Lemons ◽  
Ariel Branz ◽  
Mesiaki Kimirei ◽  
Tracy Hawkins ◽  
Daniele Lantagne

Globally, approximately two billion people drink contaminated water. Use of household water treatment (HWT) methods, such as locally manufactured ceramic filters, reduces the diarrheal disease burden associated with unclean water. We evaluated the quality, effectiveness, and acceptability of ceramic filters in two communities in Arusha, Tanzania, by conducting: 1) baseline household surveys with 50 families; 2) filter flow rate testing; 3) filter distribution with training sessions; 4) follow-up surveys at 2, 4, and 6 weeks after distribution; and 5) project end focus group discussions. We tested Escherichia coli (E. coli) and turbidity at baseline and the first two follow-ups. We found: 1) filter quality was low, as only 46% of filters met recommended flow rate guidelines and 18% of filters broke during the 6-week study; 2) filter effectiveness was moderate, with 8% and 35% of filters effectively reducing E. coli to <1 CFU/100 mL and <10 CFU/100 mL, respectively, at follow-ups; and, 3) filter acceptability was high, with 94% overall satisfaction and 96–100% reported use in the previous day. These results highlight the importance of mixed methods research as HWT product quality, effectiveness, and acceptability all impact product efficacy, and the need for quality assurance/quality control and certification schemes for locally manufactured HWT products.


2018 ◽  
Vol 17 (2) ◽  
pp. 266-273 ◽  
Author(s):  
D. Brown ◽  
C. Farrow ◽  
E. A. McBean ◽  
B. Gharabaghi ◽  
J. Beauchamp

Abstract Diarrheal illnesses and fatalities continue to be major issues in many regions throughout the world. Household water treatment (HWT) technologies (including both point-of-use (POU) and point-of-entry (POE) treatment solutions) have been shown as able to deliver safe water in many low-income communities. However, as shown herein, there are important inconsistencies in protocols employed for validating performance of HWTs. The WHO does not stipulate influent concentration as a parameter that could influence removal efficacy, nor does it indicate an influent concentration range that should be used during technology evaluations. A correlation between influent concentration and removal is evidenced herein (R2 = 0.88) with higher influent concentrations resulting in higher log-removal values (LRVs). The absence of a recommended standard influent concentration of bacteria (as well as for viruses and protozoa) could have negative consequences in intervention efforts. Recommendations are provided that regulatory bodies should specify an influent concentration range for testing and verification of HWT technologies.


2009 ◽  
Vol 43 (14) ◽  
pp. 3559-3565 ◽  
Author(s):  
Angela R. Bielefeldt ◽  
Kate Kowalski ◽  
R. Scott Summers

2012 ◽  
Vol 47 (1) ◽  
pp. 429-435 ◽  
Author(s):  
Ryan W. Schweitzer ◽  
Jeffrey A. Cunningham ◽  
James R. Mihelcic

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 285
Author(s):  
Nkosinobubelo Ndebele ◽  
Joshua N. Edokpayi ◽  
John O. Odiyo ◽  
James A. Smith

In this study, we report on field testing of ceramic water filters (CWFs) fabricated using a new method of silver application (using silver nitrate as a raw material) compared to conventionally manufactured CWFs (fabricated with silver nanoparticles). Both types of filters were manufactured at the PureMadi ceramic filter production facility in Dertig, South Africa. Thirty households received filters fabricated with silver nitrate (AgNO3), and ten of those households were given an extra filter fabricated with silver nanoparticles. Filter performance was quantified by measurement of total coliform and Escherichia coli (E. coli) removal and silver residual concentration in the effluent. Silver-nitrate CWFs had removal efficiencies for total coliforms and E. coli of 95% and 99%, respectively. A comparison of the performance of silver-nitrate and silver-nanoparticle filters showed that the different filters had similar levels of total coliform and E. coli removal, although the silver nitrate filters produced the highest average removal of 97% while silver nanoparticles filters recorded an average removal of 85%. Average effluent silver levels were below 10 ppb for the silver-nitrate and silver-nanoparticle filters, which was significantly below the Environmental Protection Agencies of the United States (EPA) and World Health Organization (WHO) secondary guidelines of 100 ppb. Silver-nitrate filters resulted in the lowest effluent silver concentrations, which could potentially increase the effective life span of the filter. A cost analysis shows that it is more economical to produce CWFs using silver nitrate due to a reduction in raw-material costs and reduced labor costs for production. Furthermore, the production of silver-nitrate filters reduces inhalation exposure of silver by workers. The results obtained from this study will be applied to improve the ceramic filtration technology as a point-of-use (POU) water treatment device and hence reduce health problems associated with microbial contamination of water stored at the household level.


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