New Method for the Deposition of Metallic Silver and Metallic Copper on Full-Size Porous Ceramic Water Filters

2019 ◽  
Vol 36 (1) ◽  
pp. 2-11 ◽  
Author(s):  
Kathryn N. Jackson ◽  
James A. Smith ◽  
Joshua N. Edokpayi
Keyword(s):  
Porous Ceramic ◽  
Metallic Copper ◽  
New Method ◽  
Metallic Silver ◽  
Full Size ◽  
Ceramic Water Filters ◽  
Water Filters

scholarly journals Does Activated Silver Reduce Recontamination Risks in the Reservoirs of Ceramic Water Filters?

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1108
Author(s):  
Regula Meierhofer ◽  
Pascal Rubli ◽  
Jared Oremo ◽  
Alloyce Odhiambo
Keyword(s):  
Water Storage ◽  
Water Reservoir ◽  
Silver Ions ◽  
Field Trials ◽  
Metallic Silver ◽  
Silver Coating ◽  
Filter Performance ◽  
Ceramic Water Filters ◽  
Significant Difference ◽  
Water Filters

Efforts to provide safe water are challenged by recontamination and regrowth of pathogens in treated water during storage. This study evaluated the potential of metallic silver with a chemically etched surface to reduce recontamination risks during water storage in ceramic water filters. Batch experiments were conducted in the laboratory with water storage buckets containing three configurations of varying amounts of silver. Field trials in a rural area in Kenya assessed the effect of the same configurations in the storage buckets of locally produced ceramic pot filters without colloidal silver coating. The tests revealed that the etched silver slightly reduced microbiological recontamination risks during water storage despite the low diffusion of silver ions (<5 µg Ag/L). The effect was strongly influenced by water chemistry parameters. A statistically significant difference in the removal of E. coli (Δ Log Removal Value (LRV) = 0.6) and total coliforms (Δ LRV = 1.7) was found between households using a filter with silver in the water reservoir and those using a filter without silver. Multivariate regression of water handling factors and hygiene practices on filter performance revealed that the presence of silver in the reservoir and cleaning the filter element with a brush were associated with a better filter performance.

A New Method for Nanosilver Application in Ceramic Water Filters

2016 ◽  
Author(s):  
Kathryn Nunnelley ◽  
James A. Smith ◽  
Matthew Y. Smith ◽  
Amidou Samie
Keyword(s):  
New Method ◽  
Ceramic Water Filters ◽  
Water Filters

scholarly journals A New Method for the Deposition of Metallic Silver on Porous Ceramic Water Filters

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Kathryn N. Jackson ◽  
James A. Smith
Keyword(s):  
Silver Nanoparticles ◽  
Silver Nitrate ◽  
Removal Rate ◽  
Aqueous Suspension ◽  
Porous Ceramic ◽  
New Method ◽  
Metallic Silver ◽  
E Coli ◽  
Filter Performance ◽  
Continuous Feed

A new method of silver application to a porous ceramic water filter used for point-of-use water treatment is developed. We evaluated filter performance for filters manufactured by the conventional method of painting an aqueous suspension of silver nanoparticles onto the filter and filters manufactured with a new method that applies silver nitrate to the clay-water-sawdust mixture prior to pressing and firing the filter. Filters were evaluated using miscible displacement flow-through experiments with pulse and continuous-feed injections of E. coli. Flow characteristics were quantified by tracer experiments using [3H]H2O. Experiments using pulse injections of E. coli showed similar performance in breakthrough curves between the two application methods. Long-term challenge tests performed with a continuous feed of E. coli and growth medium resulted in similar log removal rates, but the removal rate by nanosilver filters decreased over time. Silver nitrate filters provided consistent removal with lower silver levels in the effluent and effective bacterial disinfection. Results from continued use with synthetic groundwater over 4 weeks, with a pulse injection of E. coli at 2 and 4 weeks, support similar conclusions—nanosilver filters perform better initially, but after 4 weeks of use, nanosilver filters suffer larger decreases in performance. Results show that including silver nitrate in the mixing step may effectively reduce costs, improve silver retention in the filter, increase effective lifespan, and maintain effective pathogen removal while also eliminating the risk of exposure to inhalation of silver nanoparticles by workers in developing-world filter production facilities.

Ceramic Water Filters as a Response Technology to Geo-Hazards

2018 ◽  
Vol 5 (1) ◽  
pp. 1-8
Author(s):  
E. McBean ◽  
◽  
G. Huang ◽  
Yongping Li ◽  
Yanfeng Li ◽  
...  
Keyword(s):  
Ceramic Water Filters ◽  
Water Filters

Virus removal efficiency of ceramic water filters: effects of bentonite turbidity

2013 ◽  
Vol 14 (2) ◽  
pp. 304-311 ◽  
Author(s):  
Cameron Farrow ◽  
Edward McBean ◽  
Hamidreza Salsali
Keyword(s):  
Removal Efficiency ◽  
Potable Water ◽  
Source Water ◽  
Virus Removal ◽  
Ceramic Water Filters ◽  
Point Of Use ◽  
Cake Layer ◽  
Human Enteric Viruses ◽  
Removal Efficiencies ◽  
Water Filters

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 (&lt;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.

scholarly journals Performance of black ceramic water filters and their implementation in rural Ecuador

2019 ◽  
Vol 9 (4) ◽  
pp. 694-702 ◽  
Author(s):  
Laura Guerrero-Latorre ◽  
Priscila Balseca-Enriquez ◽  
Carlos Moyota-Tello ◽  
Ronald Bravo-Camino ◽  
Stephanie Davila-Chavez ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
New Technology ◽  
Classical Model ◽  
International Standards ◽  
Household Water Treatment ◽  
Household Level ◽  
Ceramic Water Filters ◽  
Field Level ◽  
Water Filters

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.

Development of improved low-cost ceramic water filters for viral removal in the Haitian context

2014 ◽  
Vol 5 (1) ◽  
pp. 28-38 ◽  
Author(s):  
L. Guerrero-Latorre ◽  
M. Rusiñol ◽  
A. Hundesa ◽  
M. Garcia-Valles ◽  
S. Martinez ◽  
...  
Keyword(s):  
Low Income ◽  
Low Cost ◽  
World Health ◽  
Low Income Countries ◽  
Virus Removal ◽  
Ceramic Water Filters ◽  
Removal Efficiencies ◽  
Reductive Atmosphere ◽  
Health Organization ◽  
Water Filters

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.

Impact of chlorination on silver elution from ceramic water filters

2018 ◽  
Vol 142 ◽  
pp. 471-479 ◽  
Author(s):  
Bonnie A. Lyon-Marion ◽  
Anjuliee M. Mittelman ◽  
Justine Rayner ◽  
Daniele S. Lantagne ◽  
Kurt D. Pennell
Keyword(s):  
Ceramic Water Filters ◽  
Water Filters

scholarly journals Effect of Chloride Ions on the Point-of-Use Drinking Water Disinfection Performance of Porous Ceramic Media Embedded with Metallic Silver and Copper

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1625
Author(s):  
Rekha Singh ◽  
Woohang Kim ◽  
James A. Smith
Keyword(s):  
Drinking Water ◽  
Porous Ceramic ◽  
Chloride Ion ◽  
Silver Ions ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Metallic Silver ◽  
E Coli ◽  
Ion Concentrations ◽  
Copper Release

This study quantifies the effects of chloride ions on silver and copper release from porous ceramic cubes embedded with silver and copper and its effect on E. coli disinfection in drinking water. Log-reduction of E. coli by silver ions decreased after 4 h of contact time as the chloride ion concentration increased from 0 to 250 mg/L but, it was not changed by copper ions under the same conditions. For silver addition by silver-ceramic cubes, log reductions of E. coli decreased sharply from 7.2 to 1.6 after 12 h as the chloride concentration increased from 0 to 250 mg/L. For the silver-ceramic cube experiments, chloride ion also reduced the total silver concentration in solution. After 24 h, total silver concentrations in solution decreased from 61 µg/L to 20 µg/L for corresponding chloride ion concentrations. According to the MINTEQ equilibrium model analysis, the decrease in disinfection ability with silver embedded ceramic cubes could be the result of precipitation of silver ions as silver chloride. This suggests that AgCl was precipitating within the pore space of the ceramic. These results indicate that, although ionic silver is a highly effective disinfectant for E. coli, the presence of chloride ions can significantly reduce disinfection efficacy. For copper-ceramic cubes, log reductions of E. coli by copper embedded cubes increased from 1.2 to 1.5 when chloride ion concentration increased from 0 to 250 mg/L. Total copper concentrations in solution increased from 4 µg/L to 14 µg/L for corresponding chloride ion concentrations. These results point towards the synergistic effect of chloride ions on copper oxidation as an increased concentration of chloride enhances copper release.

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