Electroplating wastewater zero-discharge or low-discharge handling method

Abstract

The invention provides a processing method for zero draining or low draining of electroplating wastewater. The method adopts an integrative technique, such as barrier concentration, barrier separation, ion exchange, and ultraviolet light catalytic oxidation, etc. The following steps are adopted: the pretreatment of the electroplating wastewater; the treatment for the three types of wastewater including pickling wastewater, wastewater containing cyanide and passivating and electroplating rinsing composite wastewater; and the treatment for the wastewater in an acid-soluble pool. Compared with the wastewater in an integrative electroplating plant with universal generic multi-plating species, only the prior water separation method with no need to control the troubled water strictly can realize : first, zero draining of the electroplating wastewater is performed; second, when operating in the low energy consumption way, 65 to 85 percent of water recovery is realized, the left wastewater which can not be recovered is discharged when reaching the primary discharge standard of National Standard; third, the processing cost is reduced; fourth, the metallic ion in the wastewater can be effectively recovered and utilized, at the same time, the benefit disinvestment cost is produced; fifth, the amount for causing solid waste is reduced; sixth, the invention is advantageous to realize the automatic control and the operation.

Description

technical field

[0001] The invention relates to a treatment method for wastewater, in particular to a treatment method for electroplating wastewater. Background technique

[0002] Electroplating wastewater treatment often uses chemical precipitation method, electrolysis method, common ion exchange method and other treatment methods in the treatment process. However, the above systems have certain limitations and cannot achieve zero emissions.

[0003] The chemical precipitation method is now widely used in electroplating factories. In the production process, a large amount of acid and alkali needs to be added, as well as ferrous sulfate and polyaluminum chloride. As a result, the salinity rate of water discharge is increased, and the residual heavy metal ions in the water are still difficult to meet the discharge standard. Since the content of controlled substances specified in the waste water discharge standard is extremely low, excessive chemicals need to be invested to m...

Examples

Embodiment 1

[0073] A large-scale electroplating enterprise produces about 700 cubic meters of wastewater every day. The wastewater is classified into three routes. The first wastewater is pickling wastewater. The total amount is 200 cubic meters per day. The main components are: iron 362mg / l, pH value 2.9, Total dissolved solids 2200mg / L, grease 332mg / L, calcium and magnesium 446mg / L, total chlorine 917mg / L. The second waste water is cyanide-containing waste water, with a total amount of 200 cubic meters per day. The composition is: CN - 60mg / L, copper 6.1mg / L, zinc 117mg / L, iron 0.1mg / L, pH8.6. The third waste water is electroplating mixed waste water and passivation waste water, the total amount is 300 cubic meters per day, and the composition is: total chromium 73.6mg / L, hexavalent chromium 59.8mg / L, copper 11.34mg / L, nickel 34.5mg / L , Zinc 64.6mg / L, Iron 6.1mg / L, CN - 10mg / L, pH1.8.

[0074] Fig. 1 is the technical process of the present embodiment, and its processing steps are:

...

technical field

[0001] The invention relates to a treatment method for wastewater, in particular to a treatment method for electroplating wastewater. Background technique

[0002] Electroplating wastewater treatment often uses chemical precipitation method, electrolysis method, common ion exchange method and other treatment methods in the treatment process. However, the above systems have certain limitations and cannot achieve zero emissions.

[0003] The chemical precipitation method is now widely used in electroplating factories. In the production process, a large amount of acid and alkali needs to be added, as well as ferrous sulfate and polyaluminum chloride. As a result, the salinity rate of water discharge is increased, and the residual heavy metal ions in the water are still difficult to meet the discharge standard. Since the content of controlled substances specified in the waste water discharge standard is extremely low, excessive chemicals need to be invested to m...

Examples

Embodiment 1

[0073] A large-scale electroplating enterprise produces about 700 cubic meters of wastewater every day. The wastewater is classified into three routes. The first wastewater is pickling wastewater. The total amount is 200 cubic meters per day. The main components are: iron 362mg / l, pH value 2.9, Total dissolved solids 2200mg / L, grease 332mg / L, calcium and magnesium 446mg / L, total chlorine 917mg / L. The second waste water is cyanide-containing waste water, with a total amount of 200 cubic meters per day. The composition is: CN - 60mg / L, copper 6.1mg / L, zinc 117mg / L, iron 0.1mg / L, pH8.6. The third waste water is electroplating mixed waste water and passivation waste water, the total amount is 300 cubic meters per day, and the composition is: total chromium 73.6mg / L, hexavalent chromium 59.8mg / L, copper 11.34mg / L, nickel 34.5mg / L , Zinc 64.6mg / L, Iron 6.1mg / L, CN - 10mg / L, pH1.8.

[0074] Fig. 1 is the technical process of the present embodiment, and its processing steps are:

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