Water Treatment ppt
Water Treatment ppt
Published on 08/02/2022
Why do we need to purify water?
there are many impurities in the raw water that can harm human health if the water is ingested without treatment. These impurities can be grouped into three categories:-
Physical materials that do not dissolve in water and make appear ” dirty”
Chemical:- substances dissolved in the water from both natural and man made processes.
Biological:- virus, bacteria, algae and other small living organisms.
Objective of water treatment
- To remove colour, objectionable taste and odour.
- To remove dissolved gases, dissolved and suspended impurities and harmful minerals.
- To remove suspended and dissolved organic impurities.
- To remove harmful bacteria.
- To make the water safe and attractive for drinking and domestic purpose
Sedimentation:-
It is the tendency for particles in suspension to settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them. These forces can be due to gravity, centrifugal acceleration or electromagnetism.
Sedimentation is a physical water treatment process using gravity to remove suspended solids from water. Solid particles entrained by the turbulence of moving water may be removed naturally by sedimentation in the still water of lakes and oceans.
Sedimentation aided with coagulation
Sedimentation added with comprises of three steps
- Adding of measured quantity of chemicals called coagulants to water and their through mixing ( rapid mixing)
- formation of precipitation which coagulates and forms a flow ( flocculation )
- sedimentation
Chlorination
Water chlorination is the process of adding chlorine or chlorine compounds such as sodium hypochlorite to water. This method is used to kill certain bacteria and other microbes in tap water as chlorine is highly toxic.
Solar water disinfection
Solar water disinfection, in short sodis, is a type of portable water purification that uses solar energy to make biologically-contaminated (e.g. bacteria, viruses, protozoa and worms) water safe to drink.