Water treatment techniques

Water treatment techniques:

• ·       Sedimentation
• ·       Clarification
• ·       Disinfection
• ·       Filtration
• ·       Reverse osmosis process
• ·       Demineralization

Water treatment

Sedimentation: First the water is received in settling basin and allowed to settle down where mud, suspended solids, silts etc. gradually separate from water and deposit at the bottom.

Clarification: The clarification is a technique for purification. It is a process for removal of suspended solids, finer solids appearing as turbidity and color, also other colloidal materials.

Chemical used in clarification:

·       Aluminum sulphate A12(SO₄)₃.18H₂O as coagulant.

·       Na₂CO₃ to increase the _pH value of treated water if it is acidic.

·       Liq.C12 for removal of bacteria and algae.

Disinfection: It is accomplished both by filtering out harmful micro-organism and also by adding disinfectant chemicals.

For disinfection any of the following operations are used:

• ·       Ozonation
• ·       Ultraviolet radiation
• ·       Chlorination

Filtration: At this stage only fine soluble materials are left which are typical suspended solids less than 10 ppm. So filtration is required to remove this residual material. The top layer removes organic compounds which contribute to test and odour.

Reverse osmosis process: It is used to remove dissolved organic and inorganic materials as well as microorganism.

Demineralization: In demineralization plant ion exchange resins are used to demineralize the water. Otherwise following problems occur in boilers: scale formation, corrosion, loss of heat transfer, excess fuel consumption etc.