Water Conditioning Methods which are used for the treatment of Raw Water

Based on raw available in nature, and the impurities present in it will give an idea regarding the selection of treatment methods to be employed in water conditioning. For example, the methods which are used are:
  • Lime soda process
  • Filtration
  • Decolorisation and deodorization
  • Chlorination
  • Ion exchange  [a) Zeolite softening for cation removal  b) Synthetic resins used for cation and anion exchange]
Free software to calculate the properties of water 
The principal processes involved in most of the municipal water conditioning unit are:
1. Lime soda to precipitate calcium and magnesium as well as decolourized and remove turbidity agents
2. Activated carbon treatment
3. Filtration
4. Chlorination
Three chemical required for the lime soda process is quicklime (>90% CaO) or hydrated lime, light soda ash (98% Na2CO3) and alum [Al2(SO4)3. xH2O]. The small amount of activated carbon and chlorine or chlorine compounds such as sodium hypochlorite (NaOCl)are essential for complete conditioning of most raw water supplies.

Process description:

Raw water inflow is measured and fed to the continuous mixing unit here the water is mixed with the specified amount of the chemical ingredients which react with the component present in raw water. Initially deflocculating of turbidity components will take place. Than a precipitate of slug and mud formation is done by adding alum and soda. 

Now the treated water is called supernatant water is removed from clarifiers which follow the mixer.Bacteria can be terminated by the presence of OH- present in the water due to the removal of Mg as Mg(OH2), this effluent water will re-carbonated to neutralize the excess alkalinity, which is done by spraying combustion gas.
And finally with the addition of activated carbon which acts as adsorbent will adsorb heavy metals, chemical compound and forms into thick sludge which is then filtered by the help of filter press, with limited addition of chlorine will make water free from microorganisms.