The pre-treatment technology may need desalted water during the treatment operation. Certain chemicals also need to be solved in desalted water so the basis of the system is desalted water. Water supply is generally also done by means of desalted water and it is also worth flushing the output zones with desalted water in order to reach a better surface condition. For generating desalted water, the RO unit operating in the principle of reverse osmosis is recommended. Reverse osmosis is an environmentally friendly and economical process of desalting water.

Equipment working in the principle of reverse osmosis operates with semi-permeable membranes. These transmit the solvent through their pores, preventing the flow of the solved materials. If some type of salty solution and fresh water are separated in such a semi-permeable film, then the molecules of clear water migrate through the membrane without intervention needed to the salty solution which becomes diluted and its capacity increases. That is the process of osmosis. The process reaches its rest point once the osmotic balance sets in.

If the process is reversed and put pressure on the salty solution of higher concentration, then, after elimination of the osmotic pressure (in a reverse direction), clear water flows through the membrane. That is the process of reverse osmosis.

The equipment needs to be dimensioned always according to the generation of the necessary amount of desalted water. The necessary refreshments and desalted wet zones (they should be the standard) as well as the fact that at certain tubs desalted water may be needed for filling need to be considered.

An RO also includes a container tank which forwards the generated desalted water. The pre-treatment equipment will be supplied with the necessary amount of desalted water from that tank. The unit is controlled by a small PLC which may be handled from an attached control board.