Reverse osmosis uses pressure to force water through a semi-permeable membrane that allows water to pass but blocks dissolved salts and other molecules. In reverse osmosis, a pressurized saline solution is pumped through a membrane, separating it into a purified water stream and a concentrated brine stream. Higher pressure increases water flux through the membrane while lowering salt passage. Reverse osmosis is used to desalinate seawater, purify water, and separate dissolved materials in industrial processes.

1. Introduction to Reverse Osmosis

3. Two Compartments A Semi-permeable membrane Placed in between Concentration Solution in Left side, Dilute Solution in Right Side Dilute Solution Concentrated Solution Pressure Equilibrium Case Applied Force in Concentration Side

5. Vessel Feed Water Feed Valve Permeate Water Reverse Osmosis Process

6. Reverse Osmosis Process Recovery (%) = Permeate Flow Feed Flow Salt Passage (%) = Permeate Salt Concentration Feed Salt Concentration Salt Rejection (%) = 100 – Salt Passage

12. Range of filtration Processes Electron Microscopy Optical Microscopy Visible to Naked Eye Human Hair Sand Blood Cells Colloid Proteins / Enzymes Metal ion Bacteria Virus Yeast Cells Oil Emulsions Reverse Osmosis Nano-filtration Ultra-filtration Micro-filtration Particle Filtration Note: 1 Angstrom = 10 -10 Meters = 10 -4 Micron Ionic Range Molecular Range Micro Molecular Micro Particle Range Macro Particle Range 10 -3 10 -2 10 -1 1 10 100 Micrometer 10 10 2 10 3 10 4 10 5 10 6 Angstrom

13. Factors Influencing With increasing effective pressure The permeate flux will increase Permeate Flux Salt Rejection Pressure The permeate TDS will decrease

14. Factors Influencing With increasing Temperature The permeate flux will increase Permeate Flux Salt Rejection Temperature The salt passage will increase

15. Factors Influencing With increasing Recovery ratio The permeate flux will decreasing Permeate Flux Salt Rejection Recovery The salt rejection will decreasing

16. Factors Influencing With increasing Feed Water Salt Concentration The permeate flux will decreasing Permeate Flux Salt Rejection Feed Concentration The salt rejection will decreasing