Zero-drainage technology and equipment for treatment of wastewater with high salt content

Abstract

The invention discloses a zero-drainage technology for treatment of wastewater with high salt content. The zero-drainage technology sequentially comprises the following steps of removing of suspension matters, reducing of hardness in wastewater, separating of solid and liquid by a tubular membrane, removing of residual hardness by ion exchange resin, freshening of concentrated salt water by a microelectrolysis bipolar membrane device, and removing of salt by a reverse osmosis device, so as to obtain desalted water and acid and sodium hydroxide commodities. The invention also discloses equipment. The equipment comprises a wastewater collecting tank, a quick clarifying and separating device, a primary softening device, a secondary softening device, a TMF (tubular micro-filtration membrane) concentrated water tank, a TMF lifting pump, a TMF system, a TMF water production tank, an exchange lifting pump, an ion exchange resin device, an intermediate water production tank, an electrolysis water supply pump, the microelectrolysis bipolar membrane device, and a product water tank. The zero-drainage technology and the system have the advantages that the suspension matters in the wastewater with high salt content can be quickly removed; the hardness in the wastewater is removed; the wastewater of concentrated salt water is freshened by the microelectrolysis bipolar membrane device; the acid and sodium hydroxide commodities are produced in the wastewater freshening process; the running cost is low, the wastewater with high salt content can reach zero-drainage effect, and the additional economic value is produced.

Description

technical field [0001] The invention belongs to the technical field of waste water zero discharge and resource treatment, and specifically relates to a zero discharge process and equipment for treating high-salt waste water, which are used to turn pollutants in high-salt waste water into useful resources. Background technique [0002] Highly saline wastewater refers to wastewater with a total saline mass fraction of at least 1%. It mainly comes from chemical plants and the collection and processing of oil and natural gas. This wastewater contains a variety of substances (including salt, oil, organic heavy metals and radioactive substances). [0003] Saline wastewater is produced in a wide range of ways, and the water volume is increasing year by year. If the wastewater is discharged directly, the substances in the wastewater will have a great impact on the environment. Facing the increasing shortage of water resources today, how to comprehensively treat and reuse high-salt w...

AI Technical Summary

Problems solved by technology

For the treatment of a large amount of high-salt wastewater, in order to reduce the amount of high-salt wastewater entering the evaporation crystallizer, it is necessary to concentrate the high-salt wastewater, but because the wastewater contains a large salinity, direct concentration will have many problems. Therefore, it is necessary to pretreat the wastewater to ensure the stable operation of the membrane concentration device. However, even if there is sufficient pretreatment for high-salt water, there is still a risk of fouling on the concentrated water side of the membrane concentration. In addition, the process of membrane concentration is easy. Fouling and easy to clog, requiring frequent chemical cleaning of the membrane, which reduces the service life of the membrane

[0005] This method of treating high-salt wastewater not only has high investment costs, but also high operating costs, and will eventually produce solid waste—miscellaneous salt

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