Can anyone suggest a low cost water filter for individual household that can remove iron as well as arsenic?
A question from Sudip : In West Bengal (India) the problem of arsenic is huge and we are searching for low cost water filter for individual house hold that can remove iron as well as arsenic. Can you help? We found a model which was being promoted by unicef but that has been stopped two year back. can you provide us any light in this direction.
Another low cost option developed with Bangladesh in mind is arsenic phyto-extraction.
This method was developed by Stephen Goodwin Honan a PhD student from Oxford University. His "Clean Water" uses plastic containers and local ferns to extract the arsenic, although I'm not sure whether it has any impacts on iron levels.
Unfortunately there is no specific website on the technology, but a short overview can be found here. a 500 strong field testing was ongoing in 2014,. http://www.dezeen.com/2013/09/17/plan...
There has been substantial research into different technologies for arsenic removal, which the Practical Action paper that Binaya has provided covers very comprehensively. I carried out some research on different technologies a couple of years ago and one of the most practical household systems I came across was the Kanchan Arsenic Filter or KAF. A paper reporting the results from field tests on the KAF in Cambodia is here: http://web.mit.edu/watsan/Docs/Other%20Documents/KAF/Cambodia%20KAF%20Phase%20I%20Technical%20Report%20FINAL%20Sep08.pdf
The most common household technologies for arsenic and iron removal use filtration/sedimentation techniques of their insoluble compounds. A word of caution, therefore, needs to be given as at some point the waste products from the filters must be disposed of. It is imperative that thought is given to where a suitable disposal site is located which should not be close to an area that could further contaminate the groundwater. The subsurface aerated water injection process gets around this problem by oxidising the arsenic to an insoluble form within the borehole, so leaving it behind when the water is extracted. But this technology is perhaps more community based than household.
One of the greatest challenges of arsenic removal at household level is also ensuring that the technology is indeed working. There are no simple indicators, such as colour, smell or even taste, to show that the arsenic has been removed and using any handheld technologies is too expensive for day to day use. This is perhaps the next big challenge for research.
Got one response from Katy Alexander via Facebook: A Simple household device to remove arsenic from groundwater and two years performance report of arsenic removal plant for treating ground water with community participation: http://users.physics.harvard.edu/~wil...
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