Treatment method for electroplating industrial wastewater

Abstract

The embodiment of the invention discloses a treatment method for electroplating industrial wastewater, which comprises the following steps: pretreating nickel-containing wastewater; pretreating chromium-containing wastewater; pretreating copper-containing wastewater in a manner the same with the nickel-containing wastewater pretreatment manner; pretreating cyanide-containing wastewater; treating electroplating mixed wastewater, wherein the electroplating mixed wastewater comprises pretreatment wastewater, cleaning wastewater, electroplating wastewater and the like generated in a workshop production process and also comprises the pretreated nickel-containing wastewater, chromium-containing wastewater, copper-containing wastewater and cyanide-containing wastewater; discharging these pretreated four wastewater to a comprehensive wastewater collection tank together with other pretreatment wastewater, cleaning wastewater and the like, wherein a stirring system is arranged in the comprehensive collection tank; and finally, performing comprehensive electroplating wastewater treatment. According to the invention, non-toxic and harmless chemical reaction treatment is performed on the heavy metals and virulent cyanide, thus realizing one-stop circular electroplating wastewater treatment, improving the treatment efficiency of the electroplating industrial wastewater and reducing the water pollution.

Description

technical field [0001] The invention belongs to the field of industrial wastewater treatment, in particular to a treatment method for electroplating industrial wastewater. Background technique [0002] Electroplating wastewater usually contains highly toxic substances such as copper Cu, nickel Ni, chromium Cr, and cyanide, which are mainly divided into the following categories: (1) Chromium-containing wastewater: pH=2~6, [Cr6+]≤80mg / L; (2) Copper-containing wastewater: pH=7.5~8.5, [Cu2+]=30~45mg / L; (3) Nickel-containing wastewater: pH=3~5, [Ni2+]=40~65mg / L; (4) Cyanide wastewater: pH=5~8, [CN2+]=30~50mg / L; (5) Pretreatment wastewater: pH=6~7, [Ni2+]=5~10mg / L, [Zn2+]=30~40mg / L L, [Cu2+]=3~5mg / L, petroleum=50-75mg / L. (6) Comprehensive wastewater: CODcr=100-300mg / L, SS=100-400mg / L. The treatment of electroplating wastewater is generally valued at home and abroad, and a variety of treatment technologies have been developed to eliminate and reduce the discharge of heavy metals...

AI Technical Summary

Problems solved by technology

But at present, there are certain disadvantages or serious irrationality, which make the treatment of electroplating wastewater insufficient, fail to meet the national standard discharge requirements, and pollute the environment.

[0004] Especially for the chemical precipitation method, there are mainly the following problems in the treatment of electroplating wastewater: (1) the existing technological process uses sodium hypochlorite to reduce, and the cyanide complex cannot be separated, so that the treated water cannot be discharged up to the standard

(2) Since the existing technological process cannot break the complexes in the water body, each wastewater of electroplating wastewater is mixed with different complexes. If only a single chemical treatment is used, all the complexes cannot be completely decomposed. In the absence of reduction of the complex, it is useless to use more chemicals, and the toxic and harmful substances cannot be removed by precipitation. It can only be diluted and discharged with a large amount of clean water, which still causes damage to the environment while wasting water resources.

[0005] Therefore, in view of the above-mentioned defects existing in the current prior art, it is necessary to carry out research to provide a solution to solve the defects existing in the prior art, avoiding the incomplete treatment of electroplating wastewater and failing to meet the discharge requirements of environmental protection standards

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