Combined treatment device and process for acid-washing wastewater of stainless steel

Abstract

The invention relates to combined treatment device and process for acid-washing wastewater of stainless steel, and belongs to the technical field of environment engineering, and solves the problem of environmental pollution and resource waste. The device comprises a wastewater pond, a filter connected with the wastewater pond, a primary cation exchanger connected with the filter, a secondary cation exchanger connected with the primary cation exchanger, a safety filter connected with the secondary cation exchanger and a reverse osmosis device connected with the safety filter. The first and second cation exchangers are provided with regenerated acid liquor adding ports. The device further comprises a heavy metal gas remover connected with the first and second cation exchangers. The heavy metal gas remover is provided with a settling agent adding port. A circulating pipeline for transporting filtered water in the heavy metal gas remover to the wastewater pond is arranged between the heavy metal gas remover and the wastewater pond. Wastewater meets the standard and is discharged, and wastes are recycled, so that the resources are greatly saved.

Description

technical field [0001] The invention relates to the technical field of environmental engineering, in particular to a combined treatment device and process for stainless steel pickling wastewater. Background technique [0002] In the manufacture of stainless steel, in order to remove the scale on the surface of the steel after annealing, a mixed acid made of nitric acid and hydrofluoric acid is generally used for surface cleaning, which is called pickling. With the development of the iron and steel industry and the surface treatment industry, the annual production of pickling waste liquid in the country exceeds one million cubic meters, and its pollution hazard is obvious. The main hazard of acid-containing wastewater is to corrode hydraulic structures such as sewer pipes and reinforced concrete. Acid-containing wastewater seeps into the soil. After a long time, it will cause soil calcification and damage the loose state of the soil layer, thus affecting the growth of crops; ...

AI Technical Summary

Problems solved by technology

The main hazard of acid-containing wastewater is to corrode hydraulic structures such as sewer pipes and reinforced concrete. Acid-containing wastewater seeps into the soil. After a long time, it will cause soil calcification and damage the loose state of the soil layer, thus affecting the growth of crops; acid-containing wastewater is discharged into the water body When the oxygen is taken away from the water, the living conditions of the fish and the self-purifying microorganisms participating in the self-purification of the water are destroyed, causing the death of the fish; the pickling wastewater contains heavy metals such as chromium, and excessive chromium is human carcinogenic

[0003] The traditional treatment of pickling wastewater is generally treated by lime neutralization and precipitation. The disadvantages of this treatment process are: 1) For wastewater with high chromium and fluorine content, the first-level neutralization and sedimentation treatment generally cannot meet the discharge standards ; 2) Cannot effectively recycle pickling wastewater, which is a great waste of resources

Images