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- Removes most pathogens and suspended solids<br>
- The silver coating ensures disinfection, so further disinfection is not needed. <br>
- Simple and cheap <br>
- Water tastes good <br>
| convalign= "top" | - Low flow rate (1-3 litres per hour)<br>
- Set up is fragile, breaks easily, allowing bad water through undetectable cracks. <br>
- Turid water plugs filter <br>
- Quality control difficult to ensure. <br>
- Dissolved compounds are not removed (same as other filters) <br>
{{Potential_Treatment_Capacity_table
}}
==Technical specification=Construction, operations and maintenance===[[Image:CPF2.png|thumb|right|200px| Cross section through a Ceramic Pot Filter.]]Ceramic pot filters usually have a diameter of about 30 cm by 25 cm deep, with an 8 litre capacity. Two variations of ceramic filters, flat-bottom and round-bottom, are currently manufactured. The ceramic pot typically sits or hangs in the top of a larger plastic or ceramic container (20-30 litres), which is fitted with a tap at the bottom. A lid is placed on top of the filter to prevent contamination. Ceramic pots are usually made from local clay mixed with a combustible material like sawdust, rice husks or coffee husks. The clay and combustible material are sieved through a fine mesh, and then mixed together with water until it forms a homogeneous mixture. The mixture is pressed into shape using a mold. When the pot is fired in a kiln, the combustible material burns out, leaving a network of fine pores through which the water can flow through. Colloidal silver is sometimes applied to the ceramic pot after firing or added to the clay mixture prior to firing. Colloidal silver is an antibacterial which: * Disables the enzyme that pathogenic bacteria and fungi use for oxygen metabolism, thus suffocating them. <br>* Destroys pathogens with an electric charge, causing their internal protoplast to collapse. <br>* Renders pathogens unable to reproduce. <br>* Kills parasites while in their egg stage. Pathogens and suspended material are removed from water through a combination of biological and physical processes. Quality control on the size of the combustible materials used in the clay mix ensures that the filter pore size is small enough to prevent contaminants from passing through the filter. Colloidal silver aids treatment by breaking down pathogens’ cell membranes, causing them to die.
====Operation====
The estimated flow rate is 1-3 litres/hour. This is highest when the pot is full. It declines with use and accumulation of contaminants within the filter pores.
====Manufacturing====
[[Image:CPF3.jpg|thumb|right|200px| Hydraulic press used to make the filters.]]
[[Image:CPF4.jpg|thumb|right|200px| Small local filter factory.]]
Local production of the filters is common and preferable. A quality control process to ensure filter effectiveness is required. The lower container, lid and tap can usually be purchased locally.
Materials and facilities required are:
* Clay
* Combustible material (e.g. sawdust, rice husks, coffee husks)
* Colloidal silver (optional)
* Lid
* 20-30 litre ceramic or plastic container with tap
* A ceramic factory requires at least 100 m<sup>2</sup> of covered area
* 15 to 20 ton hydraulic press (can be fabricated locally)
* Filter molds (can be fabricated locally)
* Mixer for clay and combustible material (can be fabricated locally)
* Hammer mill (can be fabricated locally)
* Kiln with an internal area of at least 1 cubic metre (can be fabricated locally)
* Racks
* Work benches
* Miscellaneous tools (e.g. traditional pottery tools)
A professional potter with experience in collecting clay, making ceramic articles, semi-industrial or mass production is required. Assistants, preferably potters are required. Skill and quality control in manufacturing is essential to ensure optimum pore size, flow rate and effectiveness.
Working with presses and kilns is potentially hazardous and adequate safety precautions should be used.
====Treatment Efficiency====
{{Treatment_Efficiency
|lab:bacteria=>98-100 % <ref name=Lantagne>[[#Lantagne01|Lantagne]] (2001)</ref><ref name=Smith>[[#Smith04|Smith]] (2004)</ref>
|lab:viruses=19-99% <ref name=Lantagne/> <ref name=Halem>[[#Halem06|Van Halem]](2006)</ref><ref name=additives>Some additives to the clay may increase virus removal. </ref>
|lab:protozoa= Up to 100% <ref name=helminth/>
|lab:helminths=up to 100% <ref name=helminth> Not researched, however helminths and protazoa are too large to pass between the 0.6-3 μm pores. Therefore, up to 100% removal efficiency can be assumed.</ref>
|lab:turbidity=83-99% <ref name=Lantagne/><ref name=low>[[#Low02|Low]](2002)</ref>
|lab:iron=not available
|field:bacteria=88 - >95.1% <ref name=Smith/><ref name=Sobsey>[[#Brown and Sobsey06|Brown and Sobsey]](2006)</ref>
|field:viruses=not available
|field:protozoa=Up to 100% <ref name=helminth/>
====Maintenance====
It is recommended that the filter pot be replaced every 1-2 years. This is in part to protect against fine cracks which may have developed and are not be visible. Any cracks will reduce the effectiveness since water can short-circuit through the crack without being filtered through the ceramic pores.
Filters are cleaned by lightly scrubbing the surface when the flow rate is reduced. Some manufacturers recommend to boil the filter every three months to ensure effectiveness. Some manufacturers recommend that soap and chlorine should not be used to clean the filter. The lower container, tap and lid should be cleaned on a regular basis.
====Estimated Lifespan====
The estimated lifespan of the filer element and the receptacle is up to 5 years, but is . But generally it lasts for 1-2 yearsuntil partial replacement (exhausted/ broken filter element, broken plastic taps, or plastic bucket) is needed. The filter needs to be replaced if Replacement is strictly needed when there are any visible cracksholes that allows pathogens to enter.
====Suppliers====
Free press and kiln designs are available from Potters for Peace.
==Cost=Costs===
{{Treatment_Cost
|CapCost=US$ 1210-25
|OpCost=US$ 0
|ReplCost=US$ 4
Cost of introduction: US$ 15,000 - 30,000 for project incl. training, machinery and a first production of 500 filters. US$ 50,000 - 100,000 for project incl. production shop, training, first promotion, and 5,000 filters.
==Country =Field experiences===<br>{|style="border: 2px solid #e0e0e0; width: 20%; text-align: justify; background-color: #e9f5fd;" cellpadding="2"<!--rsr logo here-->|- style="vertical-align: top"|[[Image:akvorsr logo_lite.png|center|60px|link=http://akvo.org/products/rsr/]]<!--project blocks here-->|- style="vertical-align: bottom"|[[Image:rsr 351.jpg |thumb|center|140px|<font size="2"><center>[http://rsr.akvo.org/project/351/ RSR Project 351]<br>Cost effective means of financing WASH</center></font>|link=http://rsr.akvo.org/project/351/ ]] |} <br>
===Manuals, videos and links==* [http://s189535770.onlinehome.us/pottersforpeace/?page_id=125 Complete production manual is available from Potters for Peace]
{| style==Movies=="font-size: 125%"|-|{{#ev:youtube|JSBU-MLwDmk|200|auto|<center>ClaySure Filter Construction</center>}}|{{#ev:youtube|-2c2bmg7yCM|200|auto|<center>Filtro Atabey, por Ideac</center>}}|{{#ev:youtube|EU3rRiWsRE0|200|auto|<center>The Pot with the <br>Silver Lining - Part 1</center>}}|{{#ev:youtube|puUid4LZCwM|200|auto|<center>The Pot with the <br>Silver Lining - Part 2</center>}}|} * construction video MANUAL: [http://nldocs.youtubewatsan.comnet/watch?v=JSBUDownloaded_Files/PDF/Brown-2007-MLwDmk&feature=related nlUse.youtubepdf Use of Ceramic Water Filters in Cambodia.com/watch?v=JSBU-MLwDmk&feature=related ]Water and Sanitation Program (WSP) and UNICEF.* Explanation Espanol MANUAL: Michael Roberts. [http://www.youtubepractica.comorg/watch?v=wp-2c2bmg7yCM wwwcontent/uploads/PDF/Cambodia%20Study.youtubepdf CERAMIC WATER PURIFIER CAMBODIA FIELD TESTS: IDE Working Paper No.com/watch?v=-2c2bmg7yCM 1]. Practica Foundation. October 2003.* Panel Discussion English MANUAL: [httphttps://videowww.googleengineeringforchange.comorg/static/content/Water/S00067/videoplay?docid=6838040406197916953&hl=en videoCeramic%20filter%20manual%20no-appendices.pdf Ceramic Water Filter Handbook].googleRDIC, February 2009.com/videoplay?docid=6838040406197916953&hl=en ]
==Footnotes=References===
<references/>
==References=Acknowledgements===* Brown, J. and M. Sobsey (2006) [http://www.potterswithoutborders.com/wp-content/uploads/2012/12/Brown_and_Sobsey_2006_-_UNICEF_ceramic_filter_final_report.pdf Independent Appraisal of Ceramic Water Filtration Interventions in Cambodia: Final Report], Department of Environmental Sciences and Engineering, School of Public Health, University of North Carolina, USA.* Lantagne, D. (2001) [http://potterswithoutborders.com/wp-content/uploads/2011/06/alethia-report-2.pdf Investigation of the Potters for Peace Colloidal Silver Impregnated Ceramic Filter Report 2: Field Investigations]. Alethia Environmental for USAID, USA. Also, [http://docs.watsan.net/Downloaded_Files/PDF/Fahlin-2003-Hydraulic.pdf Report 1, 2003].* Low, J. (2002). [http://www.sswm.info/sites/default/files/reference_attachments/LOW%202001%20Appropriate%20Microbial%20Indicator%20Tests%20for%20Drinking%20Water%20in%20Developing%20Countries%20and%20Assessment%20of%20Ceramic%20Water%20Filters.pdf Appropriate Microbial Indicator Tests for Drinking Water in Developing Countries and Assessment of Ceramic Water Filters’Filters], Master of Engineering thesis. Department of Civil and Environmental Engineering, Massachusetts Institute of Technology. Cambridge, Massachusetts, USA.* Napotnik, J., Mayer, A., Lantagne, D. and K. Jellison ([http://www.sswm.info/sites/default/files/reference_attachments/NAPOTNIK%202009%20Efficacy%20of%20Silver-Treated%20Ceramic%20Filters%20for%20Household%20Water%20Treatment.pdf Efficacy of Silver-Treated Ceramic Filters for Household Water Treatment]. Department of Civil and Environmental Engineering, Lehigh University, USA. Available at: www.filterpurefilters.org/files/pdf/silver.pdf
* Smith, L. (2004) Ceramic Water Filter Use in Takeo, Cambodia – Operational Issues and Health Promotion Recommendations. Submitted in partial fulfilment as a requirement for a Master of Science in Control of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, England.
* Van Halem, D. (2006) [http://potterswithoutborders.com/wp-content/uploads/2011/06/finalcsfreport_29-10-2-van-dalem1.pdf Ceramic silver impregnated pot filters for household drinking water treatment in developing countries]. Masters of Science in Civil Engineering Thesis, Department of Water Resources, Delft University of Technology, Netherlands.* Vinka, A. et al. (2007) [http://potterswithoutborders.com/wp-content/uploads/2011/06/oyanedel-craver-and-smith-est-2008.pdf Sustainable Colloidal-Silver-Impregnated Ceramic Filter for Point-of-Use Water Treatment], Environmental Science & Technology, Vol. 42, No. 3, 927–933 {{Joinus}}