scholarly journals Virus removal efficiency of Cambodian ceramic pot water purifiers

2011 ◽  
Vol 9 (2) ◽  
pp. 306-311 ◽  
Author(s):  
Hamidreza Salsali ◽  
Edward McBean ◽  
Joseph Brunsting

Virus removal efficiency is described for three types of silver-impregnated, ceramic water filters (CWFs) produced in Cambodia. The tests were completed using freshly scrubbed filters and de-ionized (DI) water as an evaluation of the removal efficiency of the virus in isolation with no other interacting water quality variables. Removal efficiencies between 0.21 and 0.45 log are evidenced, which is significantly lower than results obtained in testing of similar filters by other investigators utilizing surface or rain water and a less frequent cleaning regime. Other experiments generally found virus removal efficiencies greater than 1.0 log. This difference may be because of the association of viruses with suspended solids, and subsequent removal of these solids during filtration. Variability in virus removal efficiencies between pots of the same manufacturer, and observed flow rates outside the manufacturer's specifications, suggest tighter quality control and consistency may be needed during production.

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.


2014 ◽  
Vol 5 (1) ◽  
pp. 28-38 ◽  
Author(s):  
L. Guerrero-Latorre ◽  
M. Rusiñol ◽  
A. Hundesa ◽  
M. Garcia-Valles ◽  
S. Martinez ◽  
...  

Household-based water treatment (HWT) is increasingly being promoted to improve water quality and, therefore, health status in low-income countries. Ceramic water filters (CWFs) are used in many regions as sustainable HWT and have been proven to meet World Health Organization (WHO) microbiological performance targets for bacterial removal (2–4 log); however, the described viral removal efficiencies are insufficient to significantly reduce the associated risk of viral infection. With the objective of improving the viral removal efficiencies of ceramic water filters, new prototypes with different oxide compositions and firing atmospheres have been developed and evaluated. For removal efficiencies human adenoviruses, MS2 bacteriophage and Escherichia coli were quantified in all prototypes. A new model of CWF that was fired in a reductive atmosphere presented virus and bacteria removal efficiencies greater than 3.0 log and 2.5 log, respectively, which would fulfill the viral targets that are recommended by the WHO. Ceramic characterization of the selected filters, which were fired in a reductive atmosphere, showed that a larger specific surface area than those of control filters and higher fraction of a positive Z-potential fraction are the most likely explanations for this increase in virus removal.


Author(s):  
S. A. Osemeahon ◽  
J. O. Okechukwu ◽  
B. J. Dimas

The lack of clean water sources due to pollution and industrialisation is a major problem in many countries including Nigeria. To overcome this challenge, various methods have been adopted including phytoremediation treatment. This study evaluates dried duckweed an aquatic plant and its removal efficiency in comparison with other locally available treatment materials. This was achieved by formulating ceramic water filters (C.W.F) categorized into four different types- clay and kaolin(P1), clay, kaolin and sawdust(P2), clay, kaolin and charcoal(P3) and clay, kaolin and duckweed(P4). These filters were subjected to contaminated water and the following physicochemical parameters Colour, pH, Conductivity(Ec), Fluoride(F-), Magnesium(Mg2+), Nitrites(NO2-), Sulphates (SO42-), Ammonia (NH3) and Total Suspended Solids (TSS) and Total Nitrogen were determined before and after filtration. In all the ceramic water filters, the filter improved by duckweed showed the best removal efficiency of Colour – 100%, Conductivity(Ec) -72.60%, Fluoride(F)- 99.82%, Magnesium(Mg2+)- 51.68% Nitrites(NO2-)-92.34, Sulphates (SO42-)- 46.09%, Ammonia (NH3)-98.75%, and Total Suspended Solids (TSS)- 85.43% and Total Nitrogen (TN) -83.79% indicating that duckweed is capable of adsorbing inorganic and organic pollutants from water.


2009 ◽  
Vol 9 (4) ◽  
pp. 469-475
Author(s):  
T. Turtiainen

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.


1995 ◽  
Vol 31 (12) ◽  
pp. 171-183 ◽  
Author(s):  
M. M. Saqqar ◽  
M. B. Pescod

The performance of the primary anaerobic pond at the Alsamra Wastewater Treatment Plant in Jordan was monitored over 48 months. Overall averages for the removal efficiencies of BOD5, COD and suspended solids were 53%, 53% and 74%, respectively. An improvement in removal efficiency with increase in pond water temperature was demonstrated. A model, which takes into account the variability of raw wastewater at different locations, has been developed to describe the performance of a primary anaerobic pond in terms of a settleability ratio for the raw wastewater. The model has been verified by illustrating the high correlation between actual and predicted pond performance.


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.


2018 ◽  
Vol 78 (9) ◽  
pp. 1879-1892 ◽  
Author(s):  
Md Khalekuzzaman ◽  
Muhammed Alamgir ◽  
Mehedi Hasan ◽  
Md Nahid Hasan

Abstract In this research, a hybrid anaerobic baffled reactor (HABR) configuration was proposed consisting of a front sedimentation chamber and four regular baffled chambers followed by two floated filter media chambers for the treatment of domestic wastewater. Performance comparison of uninsulated and insulated HABRs was carried out operating at warm temperature (18.6–37.6 °C) under variable HRTs (30 h and 20 h). The study suggests that almost similar chemical oxygen demand (91% vs 88%), total suspended solids (90% vs 95%), turbidity (98% vs 97%), and volatile suspended solids (90% vs 93%) removal efficiencies were obtained for uninsulated and insulated HABRs. Higher removal of total nitrogen (TN) of 41%, NH4+-N of 44%, and NO3−-N of 91% were achieved by the insulated HABR compared to TN of 37%, NH4+-N of 36%, and NO3−-N of 84% by the uninsulated HABR, whereas lower PO43− removal efficiency of 17% was found in the insulated HABR compared to 24% in the uninsulated HABR. This indicated insulation increased nitrogen removal efficiencies by 4% for TN, 8% for NH4+-N and 7% for NO3−-N, but decreased PO43−removal efficiency by 7%.


2014 ◽  
Vol 1030-1032 ◽  
pp. 391-395
Author(s):  
Chao Jia ◽  
Guo Ren Xu

Biomass change and removal efficiencies of suspended solids (SS) along the process in the filter were investigated. As the normal operation of the biofilter process was often influenced by the blockage, the SS and the particle size of the backwash sludge along the process were also analysed, in order to find at which position the filter is easily blocked and what causes the blockage. The results showed that the bottom of upward flow biofilter had a higher removal efficiency of SS, with the removal rate of over 70%. The biomass and the height of the filter had an obvious regularity and the biomass increased as height of the filter increased, but the biomass at the lower middle of the filter decreased with the increasing height of the filter. At the same time, the SS and the particle size of the backwash sludge along the process in the filter also indicated the similar results.


2012 ◽  
Vol 10 (2) ◽  
pp. 209-220 ◽  
Author(s):  
Lisa M. Casanova ◽  
Adam Walters ◽  
Ajith Naghawatte ◽  
Mark D. Sobsey

Sri Lanka was devastated by the 2004 Indian Ocean tsunami. During recovery, the Red Cross distributed approximately 12,000 free ceramic water filters. This cross-sectional study was an independent post-implementation assessment of 452 households that received filters, to determine the proportion still using filters, household characteristics associated with use, and quality of household drinking water. The proportion of continued users was high (76%). The most common household water sources were taps or shallow wells. The majority (82%) of users used filtered water for drinking only. Mean filter flow rate was 1.12 L/hr (0.80 L/hr for households with taps and 0.71 for those with wells). Water quality varied by source; households using tap water had source water of high microbial quality. Filters improved water quality, reducing Escherichia coli for households (largely well users) with high levels in their source water. Households were satisfied with filters and are potentially long-term users. To promote sustained use, recovery filter distribution efforts should try to identify households at greatest long-term risk, particularly those who have not moved to safer water sources during recovery. They should be joined with long-term commitment to building supply chains and local production capacity to ensure safe water access.


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