Device and method for mineralizing desalinated seawater

Abstract

The invention provides a device and a method for mineralizing desalinated seawater, and belongs to the technical field of desalinated seawater production. The device comprises a strong brine device 100, a bipolar membrane device 200 and a mineralization device 300 which are communicated in sequence, wherein the strong brine device 100 comprises a sodium sulfate concentrated solution tank 101. According to the invention, desalted water is made into a sodium sulfate solution, so that the risk of scaling and blocking is avoided during bipolar membrane electrodialysis, the operation safety of thebipolar membrane device 200 is ensured, and the corrosivity of sulfate radicals to a pipe network is reduced compared with that of chloride ions. The mineralization device 300 comprises a dilute acidtank 301 capable of controlling the pH value of acid liquor before mineralization; the dilute sulfuric acid solution enters a mineralization tower 302, so that the acidity of the solution can be effectively converted into alkalinity, and the hardness is increased; alkali generated by the bipolar membrane alkali chamber 201 enters a mineralized water mixing tank 303, so that the pH value of water produced by the mineralization tower can be adjusted, and the mineralized produced water of the seawater desalinated water meets the drinking standard.

Description

technical field [0001] The invention relates to the technical field of seawater desalination water production, in particular to a device and method for mineralizing seawater desalination water. Background technique [0002] Due to the global shortage of fresh water resources, seawater desalination, as a water resource increment technology, has developed rapidly in recent years, and some coastal water-scarce cities have already used a large amount of seawater desalination as a necessary supplement for urban water use. However, because the desalinated water basically has no buffer capacity, it will dissolve the protective scale layer on the inner wall of cast iron pipes and steel pipes, resulting in corrosion of the municipal pipe network. At the same time, the turbidity, chroma, iron content, etc. Decrease and thus fail to meet drinking water standards. Therefore, before the desalinated water enters the network, post-mineralization treatment is required to improve the buffer...

AI Technical Summary

Problems solved by technology

However, sodium chloride brine or seawater desalination reverse osmosis concentrated water used in bipolar membrane electrodialysis can cause chloride ions to enter the mineralized product water, which is easy to corrode pipe network facilities and does not meet the requirements for safe transmission and distribution; and seawater desalination reverse osmosis concentrated water The content of impurity ions is high, and it is easy to cause bipolar membrane blockage when directly used in bipolar membrane electrodialysis; at the same time, in the process of preparing acid and alkali by bipolar membrane electrodialysis, it is impossible to accurately control the acid concentration, which affects the mineralization effect and eventually leads to Substandard mineralized water and waste of production capacity

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