The poster and the treatment stages

For those of you that don't already know, here is a brief run down of the stages of water treatment used by Teuk Saat (and us in our demonstration model) and the relevant posters to go with each stage:



1) Raw water - this contains a whole host of different particle sizes as well as bacteria and viruses

2) Sedimentation and Flocculation - here we add a flocculant which 'sticks on' or adsorps the suspended particles in the water and causes them to stick together thus becoming heavier and sinking to the bottom. Here the larger suspended solids are removed.

3) Sand filtration - the sand traps the suspended solids thus reducing turbidity (cloudiness) of the water. Most if not all of the visible suspended solids are removed here.

4) Microfiltration - they use 60, 10, 5 and 1 micron filters to remove very small dirt particles which are not visible to the naked eye and to remove bacteria as it is larger than 1 micron and gets caught by the filters.

5) UV filtration - the UV light damages the DNA of the viruses which are left in the water (because they are smaller than 1 micron in size) and means that they cannot cause infection and the water is safe to drink.

6) Finally the treated water is used with chlorine to wash out the bottles to ensure the water does not get re-contaminated and then these washed bottles can be filled with clean Teuk PisSaat (drinking) water and distributed.