Denitrification process of stainless steel cold rolling mixed acid wastewater

Abstract

The invention relates to a denitrification process of stainless steel cold rolling mixed acid wastewater, which comprises the following steps of: neutralization treatment: enabling the stainless steel cold rolling mixed acid wastewater to enter a neutralization treatment facility for carrying out neutralization treatment; denitrification pretreatment: enabling the wastewater subjected to neutralization treatment to enter a denitrification pretreatment facility for carrying out the denitrification pretreatment; biological denitrification treatment: enabling the wastewater subjected to the denitrification pretreatment to enter a biological denitrification treatment facility for carrying out the biological denitrification treatment; contact oxidization treatment: enabling the wastewater subjected to the biological denitrification treatment to enter an MBR (Membrane Biological Reactor) treatment facility for carrying out contact oxidization treatment; and desalination treatment: enabling the wastewater subjected to contact oxidization treatment to enter a desalination facility for carrying out desalination treatment to obtain desalinated water subjected to treatment. In the whole treatment process of the denitrification process of the stainless steel cold rolling mixed acid wastewater, provided by the invention, wastewater emission barely exists and the treated wastewater is completely recycled.

Description

technical field [0001] The invention relates to a wastewater treatment process, in particular to a stainless steel cold-rolled mixed-acid wastewater denitrification process, which belongs to the technical field of environmental engineering water treatment. Background technique [0002] A large amount of high-concentration mixed acid (HNO 3 +HF) wastewater. At present, this part of wastewater has been directly discharged after neutralization treatment, and the high-concentration nitrate wastewater after neutralization treatment has not been denitrified. The discharged wastewater has caused serious pollution to the water environment. Therefore, this part of wastewater must be further denitrified before discharge. [0003] Wastewater biological denitrification treatment technology is widely used in municipal sewage treatment projects, and the technology is mature. However, the total nitrogen concentration of municipal wastewater is generally <300mg / L, and the BOD content in...

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Problems solved by technology

[0004] Mixed acid (HNO 3 +HF) The content of nitrate nitrogen in wastewater is high, generally 1500-10000mg / L, up to 36000mg / L, which is not conducive to the use of biological denitrification treatment, which adds great difficulty to the standard treatment of biological denitrification, and almost Does not contain BOD, the carbon source and phosphorus source required for biological denitrification must all be added additionally, and the operating cost is high

At the same time, the biological denitrification process also needs to add a pH value regulator equivalent to nitrate equivalent in the wastewater, so that the discharged wastewater still maintains a high salt content, which not only wastes a lot of pH value regulators, but also reuses the wastewater of the entire plant. Increase the difficulty

[0005] Obviously, it is difficult to adapt to the denitrification treatment requirements of stainless steel cold rolling mixed acid wastewater by using general sewage denitrification treatment technology

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