scholarly journals Field Investigation and Economic Benefit of a Novel Method of Silver Application to Ceramic Water Filters for Point-Of-Use Water Treatment in Low-Income Settings

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.

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

2009 ◽  
Vol 7 (3) ◽  
pp. 404-412 ◽  
Author(s):  
Joe Brown ◽  
S. Proum ◽  
M. D. Sobsey

The effectiveness of point-of-use water treatment may be limited by declining use over time, particularly when water treatment is introduced via targeted intervention programmes. In order to evaluate the long-term uptake and use of locally produced ceramic water filters in rural Cambodia, we visited households that had received filters as part of NGO-subsidized distribution programmes over a 4 year period from 2002 to 2006. Of the more than 2,000 filters distributed, we visited 506 randomly selected households in 13 villages spanning three provinces to assess filter time in use and to collect data on factors potentially correlated with long-term use. Results indicate that filter use declined at the rate of approximately 2% per month after implementation, largely owing to breakages, and that, controlling for time since implementation, continued filter use over time was most closely positively associated with: related water, sanitation and hygiene practices in the home; cash investment in the technology by the household; and use of surface water as a primary drinking water source.


2019 ◽  
Vol 4 (3) ◽  
pp. 315-321 ◽  
Author(s):  
Akuemaho Virgile Onésime Akowanou ◽  
Hontonho Espérance Justine Deguenon ◽  
Leo Groendijk ◽  
Martin Pépin Aina ◽  
Benjamin Kouassi Yao ◽  
...  

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.


2019 ◽  
Vol 20 (2) ◽  
pp. 633-643
Author(s):  
Xiaopeng Qi ◽  
Junwei Chen ◽  
Qian Li ◽  
Hui Yang ◽  
Honghui Jiang ◽  
...  

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.


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.


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