Reverse osmosis filter applies to high saline and alkaline area and coastal areas and is generally used for water desalination treatment. Reverse osmosis is to take advantage of semipermeable spiral membrane separation technology to remove water microorganism, colloid particles, bacteria and organic matter. The membrane with selective permeability against water or solution is called as semipermeable membrane. If fresh water is separated from salt water with semipermeable membrane that can only be permeated through by water other than solute, water on the side of fresh water will permeate through the membrane into the side of salt water. Such phenomenon is called as penetration. By applying a pressure higher than the osmotic pressure difference, water from the side of salt water will permeate into the side of fresh water through the semipermeable membrane, and such phenomenon is called as reverse osmosis.
Driven by pressure, the reserve osmosis process has no phase change and the membrane only plays the role of “screening”. Therefore the reserve osmosis separation process requires low energy consumption. Among current methods for desalination of sea water and brackish water, reserve osmosis method is the most economical and energy-efficient.
With reserve osmosis method, more than 90% soluble salts and over 99% colloid microorganism and organism can be removed from the water. Compared with other water treatment methods, reserve osmosis method has many advantages, such as no phase variation, operation under normal temperature, simple to operate, high in efficiency, small floor area, convenient to operate, low energy consumption, wide application scope, high automation degree and better effluent water quality.
