sea water due to its high salt , it can not directly be used, usually there are two ways of sea water desalination, they are distillation and reverse osmosis process

 pretreatment of seawater

no matter is the sea water desalination,  brackish water desalination, the pretreatment is the guarantee for the RO system long term stable process.....

when working out the sea water pretreatment, it is need double consider the  large microorganisms, bacteria and algae. Breeding of bacteria and algae in seawater and organisms grow.. these factors will affect badly the water intake facility and the normal operation or the Seawater desalination equipment and process piping

Cyclical high tide, low tide, the sea water is with a large number of sediment, the turbidity changes is bigg, it is easy to cause the seawater pretreatment system work is not stable. 

Sea water is corrosive, when choosing the device , Valves and piping, it will need high rotproofness.

reverse osmosis desalination device

Sea water,  high salt, high hardness, high corrosion to equipment, and large seasonal changes in water temperature makes it more complex for sea water desalination  reverse osmosis  system than the conventional brackish water desalination system, and the project investment and energy consumption is much higher too. Thus, it is need elaborate design and reasonable configuration to reduce the engineering investment and energy consumption, and then reducing water system of unit costs, and importantly ensure the system stable operating.