Zero discharge process for high-salt wastewater discharged from titanium dioxide production

Abstract

The invention relates to a zero discharge process for high-salt wastewater discharged from titanium dioxide production, and the steps are as follows: high-salt wastewater, removal of silicon by a magnesium agent, medicinal agent softening, high-density precipitation, immersion-type ultrafiltration, brackish water reverse osmosis membrane concentration, seawater desalination reverse osmosis membrane concentration, reduction of COD by catalytic oxidation, ion exchange softening, multi-stage nanofiltration salt separation, high pressure reverse osmosis membrane concentration, DTRO/ED electrodialysis concentration, and evaporation crystallization/freezing crystallization. The zero discharge process adopts corresponding treatment processes separately, realizes for the first time the zero discharge of the high-salt wastewater of titanium dioxide by a detailed control technology of each specific process in the system, ensures the normal and smooth operation of the system, and recovers a largeamount of fresh water resources and industrial salts. The purpose of resource recycling of the titanium dioxide production wastewater is realized, and on the basis of creating of certain economic benefits, significant environmental and social benefits are reflected.

Description

technical field [0001] The invention relates to a zero-discharge process for producing and discharging high-salt waste water from titanium dioxide production. Background technique [0002] With the increasing scarcity of water resources, in order to save energy and reduce consumption of large water-using enterprises, the state advocates waste water recycling, waste water reduction, and zero discharge, which not only greatly reduces sewage discharge, but also produces a large amount of industrial water and pure water for recycling. It is used in various production water links of enterprises to achieve the purpose of energy saving and emission reduction. [0003] In order to meet the needs of zero discharge and resource utilization, it is necessary to remove various ionic salts and impurities in the wastewater, that is, to separate the salt and impurities in the wastewater from water, so that the fresh water generated during the separation process can be reused in the producti...

AI Technical Summary

Problems solved by technology

However, for this kind of high-salt wastewater, due to the complexity of its water quality, there is currently no mature technical solution. Therefore, it is necessary to innovate on the basis of conventional water treatment processes, aiming at reducing turbidity, brine concentration, salt separation, and crystallization. A series of process innovations have been carried out to form a set of stable operation process

Images