Clay Water Filters for Ghana

Posted on May 13, 2013  Comments (6)

Pure Home Water, Ghana manufactures and distributes AfriClay Filters in an effort to bring clean water to 1 million people. So far they have delivered filters to provide 100,000 people clean water.

The process is simple. Water is placed in a clay filter and gravity pulls the water through the pores left in the clay during firing.

Sediment and bacteria are filtered out in several ways:

  • Physical straining: the particles are too large to fit through the pores in the clay
  • Sedimentation or adsorption: particles come to rest on or stick to the clay
  • Inertia: friction in the pores keeps the particles from passing through

Bacteria are also killed by a coating of colloidal silver (a disinfectant), which we apply to all filters that pass our quality control tests. While sediment and bacteria are filtered out, the molecules of water are small enough to pass through the pores in the clay.

The filters are sold to those who will use them. The effort has shown a willingness to pay by villagers in remote Northern Ghana (those earning < US$1/day). I imagine (I am just guessing) the prices are subsidized; in the last decade more (most?) appropriate technology solutions will have those benefiting pay something for the benefits they receive. My nephews are working on a similar effort in India, using bio sand filters, I plan to post more on that later. There is current a campaign to help fund the delivery of water filters to Indian villages.

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6 Responses to “Clay Water Filters for Ghana”

  1. Eric Yin
    May 18th, 2013 @ 9:37 am

    I think it’s the same idea just implemented slightly differently. All these filters use the small pore size of ceramics to filter out dirt and bacteria. This massively improves the water quality but won’t get rid of harmful chemicals (so don’t use the water downstream of the illegal mining operation…) or viruses. This filter plus boiling should give completely safe water.

  2. james sahn
    May 18th, 2013 @ 12:30 pm

    What a great idea! I love the idea of these efforts that give a practical solution to serious problems. As opposed to shipping in tons of bottled water, which is impractical, this gives a wonderful solution.

  3. Carl
    May 24th, 2013 @ 12:15 am

    I’ve had a chance to watch the video few days ago. Generally a good invention that might be really helpful, in any area around the world.

  4. Phil Drysdale
    June 6th, 2013 @ 5:31 pm

    Thanks for sharing this video.

    Given how big a problem getting clean water is still to much of the world it really is exciting to see many simple (and local) solutions to this problem!

  5. updates (weekly) | Sci Tech Learning
    June 8th, 2013 @ 9:05 pm

    […] Clay Water Filters for Ghana ยป Curious Cat Science and Engineering Blog […]

  6. Anonymous
    December 4th, 2020 @ 2:02 am

    Old thread but very interesting! Always interested to see comparisons between cheap point of use devices vs centralized large scale water treatment. Wonder if that was considered in these places.

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