The nature and concentration of impurities and objectionable constituents of water determine the methods to be employed for the treatment of water. Different techniques are used for removal of mechanical impurities, Clayey turbidities, Colloidal, dissolved impurities, organic matter, detergents, polycyclic aromatics, colouring substances, oils and aliphatic hydrocarbons etc. which impart taste or odour, polyvalent heavy-metal compounds, germs and bacteria
» Typical Scheme For Pre Treatment Plants
Raw water is pumped to an Aerator, which oxidizes soluble iron in the Raw Water from Ferrous to Ferric State.
Water flows to the Stilling Chamber to break the turbulence.
Water is then taken into the Flash Mixer for intimate mixing of chemicals with the raw water.
- The raw water is dosed with Alum, Lime and Polyelectrolyte to coagulate and flocculate
- the suspended / colloidal matter and form floc of higher nuclei thereby enhancing the efficiency of sedimentation.
- Chemically dosed raw water is then fed into the clariflocculator unit wherein flocculation and clarification of raw water takes place.
- The sludge generated in the clariflocculator is bled via Telescopic Bleeds to an underground Sludge Pit.
- The sludge collected from the plant is finally pumped out.
- Clarified water is collected in the launder of the clarifier located on the top periphery from where it flows to the clarified water reservoir.
- Water collected in clearified water reservoir is then pumped to various consuming points.