Reverse osmosis (RO) is currently the most mature membrane technology for desalination at a relatively low cost which is employed for approximately 50% of desalination plants in the world.

Reverse osmosis is a pressure-driven membrane separation technology with an operating pressure of 1.5–12 MPa and a cut-off limit of 0.1–1 nm, this can eliminate all suspended solids, dissolved matters, and colloid from the liquid mixture.

Reverse osmosis is the most sophisticated membrane liquid separation technology, which can block all the suspended solids, dissolved matters, colloids, all dissolved salts, and organic matters having a molecular weight greater than 100. However, leachate molecules can pass through. Taking the discharge standard into account, two stage reverse osmosis membrane treatment process is adopted in this project. The first stage reverse osmosis unit aims to treat NF effluent for leachate reuse. The second stage reverse osmosis unit treats the concentrate from the first stage to the level required for incineration. Concentrate of the second stage flows back to incinerator.