Desalination & Membrane Treatment
As populations grow and our natural resources are stretched, we must use innovation to conserve, as well as find alternatives to our limited resources. Fresh water is considered to be one of the world’s most precious resources. Unfortunately, the availability of fresh water for the future is uncertain; which is why we are looking to the oceans and brackish water to produce our drinking water.
Doosan is a world leader in desalination with a 40 percent global market share of total installed plant capacity. We are currently moving forward with research and development of new treatment technologies and improving the efficiency of existing systems. Our overall goal is to make desalination an affordable and feasible option for our clients.
Desalination of seawater can be achieved through thermal distillation as in Multi-Stage Flash (MSF), Multi-Effect Distillation (MED) and Vapor Compression. Doosan is an industry leader in large-scale thermal distillation projects through use of their single-module evaporators. Doosan-supplied desalination plants currently produce 480 million gallons per day of potable water.
Dissolved salts and minerals in water can also be removed using a semi-permeable membrane in a reverse osmosis system. During reverse osmosis (RO), pressurized water is pushed through a membrane module via a high pressure pump. The pure water or permeate comes through the membrane and is collected in the permeate tube. The solution of concentrated salts and brine water is rejected by the membrane and is collected for disposal. The amount of untreated water fed to the system versus the amount of pure, permeate water that is produced is expressed as the system recovery. The raw water feeding the RO system must be free of suspended solids and will be chemically treated to prevent the precipitation of soluble salts onto the membrane surface. Reverse osmosis can treat lake, river, ground, and seawater sources as well as tertiary treated wastewater effluent.