Our inland surface water is getting contaminated and ground water level is going down day by day. So it is required to re-use the industrial water in to the process and ensure the zero liquid discharge from every significant source of the liquid discharge. For that RO (Reverse Osmosis) Treatment is required.
When two fluids are separated by a semi permeable membrane (which lets the fluid flow through, while dissolved solids stay behind), a fluid containing a lower concentration will move through the membrane into the fluids containing a higher concentration of dissolved solids. After a while the water level will be higher on one side of the membrane. The difference in height is called the osmotic pressure. By pursuing pressure upon the fluid column, which exceeds the osmotic pressure, one will get a reversed effect. Fluids are pressed back through the membrane, while dissolved solids stay behind in the column. Using this technique, a larger part the salt content of the water can be removed.
Next to pre-treatment one can perform a chemical dosage (acid, anti-scalent), to prevent scaling and precipitation of insoluble solids to the RO membrane, such as calcium carbonate and barium sulphate on the membrane surface. The applied acids are hydrochloric acid (HCl) or sulphuric acid (H2SO4) to maintain the pH 5.5 – 6.5.
Two unit of RO (Reverse Osmosis) is employed as RO -01 & RO-02 to increase the percentage of RO permeate and make the process more efficient. This will subsequently decrease the volume percentage of RO reject and increase the salt concentration of RO reject.