Water softening and hardness removal

hardness remoaval process and different methods

1. WATER SOFTENING Removal of hardness of water PeRmanent hardness Temporary hardness Permissible limit 75 to 115 mg/l BY-KRISHNA MURARI

2. METHODS OF REMOVAL OF TEMPORARY HARDNESS 1 BOILING : MAGNESIUM BICABONATE AND MAGNESIUM CARBONATE CANNOT BE REMOVED. LARGE SCALE IS PRACTICALLY UNFEASIBLE.

3. 2 ADDITION OF LIME : LIME OR HYDRATED LIME IS ADDED TO WATER. CALCIUM CARBONATE AND MAGENESIUM HYDROXIDE IS PRECIPITATED.

4. METHODS OF REMOVAL OF PERMANENT HARDNESS LIME SODA PROCESS BASE EXCHANGE PROCESS OR ZEOLITE PROCESS DEMINERALISATION PROCESS

5. LIME SODA PROCESS LIME AND SODA ASH are added to water CALCIUM CARBONATE AND MAGENESIUM HYDROXIDE PPT ARE FORMED AND SEDIMENTED OUT IN A TANK CARBONATE HARDNESS IS REMOVED BY LIME NON CARBONATE HARDNESS IS REMOVED BY SODA

6. RECABONATION PROCESS IN LIME SODA PROCESS LITTLE QUANTITY OF CAL. CARBONATE AND Mg HYDROXIDE REMAIN AS FINELY DIVIDED PARTICLES AND MAY CAUSE TROUBLESV BY GETTING DEPOSITED ON THE FILTER TO CAUSE ENLARGEMENT OF SAND GRAINS CALLED INCRUSTATION OF FILTER MEDIA

7. DEMINERALISATION PROCESS FOR REMOVING HARDNESS REMOVAL OF MINERALS FROM WATER EITHER COMPLETELY OR REDUCING THE MINERAL CONTENT DEMINERALISED WATER CALLED DEIONISED WATER AND IS VERY SUITABLE FOR INDUSTRIAL PURPOSE SPECIALLY FOR STEAM RAISI NG IN HIGH PRESSURE BOILER WATER IS PASSED THROUGH BED OF CATION EXCHANGE RESIN AND THEN ANION EXCHANGE RESIN HYDROGEN IS EXCHANGED IN EXCEED OF SODIUM . THE CATION EXCHANGE RESIN ARE PHENOLALDEHYDE CONDENSATION PRODUCTS.