10.3.1  Bishan Gari Water Purifier

The Bishan Gari Water Purifier (Figure 10.10) is a combined coagulant–flocculant–disinfectant powder mixture produced in Ethiopia for water treatment. Bishan Gari comes in a 2.5-g sachet, which is used to treat 20 litres of water. The sachet contains aluminium sulphate as coagulant and a flocculant for reducing turbidity, and calcium hypochlorite as a disinfectant to kill bacteria and viruses.

Figure 10.10  A Bishan Gari sachet.

The directions for using Bishan Gari powder are as follows:

  1. Put 20 litres of raw water into a clean bucket.
  2. Open the Bishan Gari sachet and add the contents to the bucket.
  3. Stir rapidly with a stick for 2 minutes (to disperse the chemicals) and then stir slowly for an additional 3–4 minutes (to help the solid particles come together to form larger particles or flocs).
  4. Wait for at least 20 minutes for the flocs to settle and the micro-organism to die. The longer you wait, the clearer the treated water will be.
  5. Strain the water through a thick cotton cloth into a safe water storage container, from which it can be consumed.
  6. Dispose of the material that settles at the bottom of the bucket by burying it.

10.3  Household water treatment using commercial products

10.3.2  Aquatabs