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Arsenic filter

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There are at least five ways to remove arsenic from drinking water. The adsorption method, the coagulation-flocculation method, the surface complexation method, a Kanchan arsenic filter, or removal by oxidation.
'''Adsorption: Magc-Alcan Filteror the Shapla filter'''<br>The Magc-Alcan is a two bucket filter. The buckets are in series and both filled with an American-made activated alumina media. The media has been developed by MAGC Technologies and Alcanof US; and it is produced by thermal dehydration (at 250-1150°C) of an aluminium hydroxide. The Magc-Alcan filter removes arsenic by adsorption (adhesion or sticking together) of the arsenic to the enhanced activated alumina which is porous and has a high surface area. Removal rates can be sensitive to varying pH levels, so additional equipment may be required to control pH levels. A similar filter called “Nirmal Filter” also exists in India. It uses arsenic adsorption on an Indian-made activated alumina and it is followed by filtration through a ceramic candle. It is less expensive than a Magc-Alcan filter ($10-15 capital cost) but it needs to be regenerated every 6 months.Efficiency: 80-90% arsenic removal. The Shapla filter is an earthen household arsenic removal technology developed by International Development Enterprises (IDE), Bangladesh. It is based on adsorption (adhesion or sticking together) of the arsenic to the iron on the coated brick chips, which works as well as iron coated sand. The bricks are coated by treatment with a ferrous sulphate solution (Ahmed, 2005). The filter can hold up to 30 litres of water. As water passes through the filter, arsenic from the water is rapidly adsorbed by the iron on the brick chips. The media (20 kg) filters 4,000 litres of arsenic-contaminated water reducing arsenic concentrations to undetectable levels and supplying an average family with 25-32 litres of safe drinking water per day.
'''Coagulation-Flocculation: Bucket Treatment Unit (BTU)'''<br>
==Construction, operations and maintenance==
'''Adsorption: Magc-Alcan Filter'''<br>
* Place two buckets (with taps) filled with activated alumina media in series using a stand.
* Place a safe water container after the second tap.
* Pour water in the top bucket with all of the taps open.
 
'''Adsorption: Shapla filter'''<br>
* Pour the water into the filter and allow it to pass through the filter medium.
* The used filter media is non-toxic and can be disposed of safely without danger to the environment or human health.
* The media container is re-useable and easily maintained.
 
'''Coagulation-Flocculation: Bucket Treatment Unit (BTU)'''<br>
'''Surface complexation: Sono Filter'''<br>
 
'''Kanchan Arsenic Filter'''<br>
 
 
'''Passive Oxidation'''<br>
 
==Costs==
{|border="1" cellspacing="0"
|-
! scope="col" |Treatment Efficiency
! scope="col" |Production
! scope="col" |Cost
! scope="col" |Lifespan
|-
|Magc-Alcan: 80-85% arsenic removal. Nirmal: 80-90% arsenic removal
|100 litres/hour
|$35-50 capital cost
|6 months to 1 year
|}
==Acknowledgements==
* [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0CHMQFjAC&url=http%3A%2F%2Fwww.cawst.org%2Ffr%2Fresources%2Fpubs%2Fcategory%2F25-fact-sheets-academic%3Fdownload%3D40%253Ahwts-fact-sheetarsenic-removalpdfoct09&ei=oi32T5bROeWW2AWl-fDCBg&usg=AFQjCNHtsMduzuzEZMNKHgbl2BN1dHjr2g&sig2=VgGZabK2qsBHhJQkLL2TKQ Household Water Treatment for Arsenic Removal Fact Sheet: Adsorption.] CAWST.
 
* [http://www.cawst.org/en/resources/pubs/category/24-fact-sheets-simplified Household Water Treatment Fact Sheets.] CAWST.
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