Brackish water desalination method and device

Abstract

The invention discloses a brackish water desalination method. The method comprises the following steps: introducing brackish water into a water collecting well; introducing brackish water in the watercollecting well into a filtering tank through a water pump, and filtering; enabling the filtered brackish water to enter a first capacitive deionization device, switching on a power supply of the first capacitive deionization device, and adsorbing positive ions and negative ions in the brackish water solution to an electrode of the first capacitive deionization device to achieve desalination andreduce the ion concentration in the brackish water solution; and enabling the desalted brackish water to pass through a reverse osmosis device under the action of a high-pressure pump to obtain freshwater. The first capacitive deionization device and a second capacitive deionization device are connected in parallel, and when the first capacitive deionization device performs reverse ion desorption, the second capacitive deionization device continues to perform desalination work, so that the desalination efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of brackish water desalination, and relates to a brackish water desalination method and device. Background technique [0002] Distillation, reverse osmosis and electrodialysis are mostly used in the desalination of brackish water at present. Distillation is the earliest desalination method. It has the advantages of simple structure, easy operation and good water quality, but the disadvantage is that , Distillation requires heat source, high energy consumption, high operating costs, and high equipment investment. The working principle of electrodialysis: Under the action of a direct current electric field, ions in water pass through a selective ion exchange membrane and migrate directionally, so that electrolyte ions are partially separated from the aqueous solution to produce fresh water, but the electrodialysis method consumes electricity and The amount of water is very high. Reverse osmosis (RO) is a memb...

AI Technical Summary

Problems solved by technology

[0002] Distillation, reverse osmosis and electrodialysis are mostly used in the desalination of brackish water at present. Distillation is the earliest desalination method. It has the advantages of simple structure, easy operation and good water quality, but the disadvantage is that , Distillation requires a heat source, high energy consumption, high operating costs, and high equipment investment

The working principle of electrodialysis: Under the action of a direct current electric field, ions in water pass through a selective ion exchange membrane and migrate directionally, so that electrolyte ions are partially separated from the aqueous solution to produce fresh water, but the electrodialysis method consumes electricity and The amount of water is very high. Reverse osmosis (RO) is a membrane separation process driven by pressure. In terms of comprehensive investment and operating costs, reverse osmosis has an absolute advantage. However, although reverse osmosis operates at room temperature, the equipment is simple, and the operation is convenient. And the energy consumption is less, but the desalination and desalination of brackish water requires higher operating pressure, which brings faster inorganic fouling on the membrane surface and frequent cleaning and replacement of membrane elements

[0003] Chinese patent CN108314121A discloses a brackish water desalination device and brackish water desalination method, including an inner circulation structure and an outer circulation structure, the inner circulation structure and the outer circulation structure form a double-layer structure; the inner circulation structure is used to desalinate brackish water The first water circulation network, the outer circulation structure forms the second water circulation network for desalinating brackish water; the inner circulation structure includes solar collectors, which are used to collect heat during the day and store it in the first water circulation network; During the circulation process of the first water circulation network, desalinated water is formed through evaporation and condensation, and the heat is transferred to the second water circulation network, so that the second water circulation network can obtain heat and store it; at night, the heat accumulated in the first water circulation network and the second water circulation network is released , so that the brackish water is condensed to form desalinated water in the circulation process of the second water circulation network. The disadvantage of this technical method is that the desalination of brackish water by solar heat collection is greatly affected by the climate, and the conversion efficiency is low. If a large amount of Desalination of brackish water requires a large area of ​​equipment

Images