Seawater desalination treatment technology _ method

Seawater desalination treatment technology _ method

Original Title: Treatment Technology of Seawater Desalination Since the 1950s, seawater desalination technology has become one of the important ways to develop new water sources. Different departments and fields have different requirements for water quality. Let's take a look at the desalination technology: 1. Distillation method of seawater desalination treatment technology: A method of heating water to 105 ° C to vaporize and then condensing the vapor to obtain distilled water. The device has the advantages of simple structure, easy operation and good fresh water quality. Disadvantages: high energy consumption. 2. Method of seawater desalination treatment technology-electrodialysis method: By utilizing the selective permeability of anion and cation exchange membranes to anions and cations in water, a part of ions in water is transferred to another part of water under the action of an external direct current electric field to achieve the purpose of desalting. The key technology of this method is the development of a new type of ion exchange membrane. The ion exchange membrane is a functional membrane with a thickness of 0.5-1.0mm, and is divided into a positive ion exchange membrane (positive membrane) and a negative ion exchange membrane (negative membrane) according to the selective permeability. Electrodialysis is a process in which selectively permeable cation membranes and anion membranes are alternately arranged to form a plurality of mutually independent compartments for desalination of seawater, and the seawater in adjacent compartments is concentrated to separate fresh water from concentrated water. Electrodialysis can not only desalinate seawater, thin film distillation ,wiped film distillation, but also be used as a means of water quality treatment to contribute to the reuse of sewage. 3. Method of seawater desalination treatment technology-ion exchange method: A method for removing anions and cations in water by exchanging ions on ion exchange resin with ions in water. 4. Seawater desalination treatment technology — — reverse osmosis membrane method: Reverse osmosis, also known as ultrafiltration, is a membrane separation desalination method adopted in 1953. Seawater is separated from fresh water by a semipermeable membrane that allows only the solvent to pass through and not the solute. Under normal circumstances, fresh water diffuses to the seawater side through the semi-permeable membrane, so that the liquid level on the seawater side gradually rises until a certain height, which is called osmosis. 5. Method of seawater desalination treatment technology-membrane distillation desalination technology: Membrane distillation is a process of retrograde evaporation of heated seawater through a porous hydrophobic membrane (sometimes called a distillation membrane), with the evaporated vapor condensing on the other side of the membrane. The hydrophobic film acts as an interface between the liquid and the vapor. This distillation method is different from the conventional distillation apparatus, which greatly reduces or even eliminates the vapor space, but the hydrophobic membrane can not replace the heat exchange surface, and in the membrane distillation device,decarboxylation after extraction, the heat exchange surface with the same area as the membrane needs to be designed. At present, there are three kinds of membrane distillation devices: air gap type, direct contact type and scavenging type. Return to Sohu to see more Responsible Editor:. toptiontech.com


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