Electroplating comprehensive wastewater zero-discharge treatment system and process thereof

Abstract

The invention provides a treatment system for zero discharge of comprehensive electroplating wastewater and a treatment process thereof. The invention belongs to the technical field of sewage treatment, and relates to a zero-discharge treatment system for comprehensive electroplating wastewater. Comprising a physicochemical system, a biochemical system, a membrane concentration system, a special pretreatment system and an evaporation system which are connected in sequence. According to the invention, the high-salt concentrated water subjected to membrane concentration can be treated by the pretreatment system before entering the evaporation system, so that pollutants influencing evaporation in the high-salt concentrated water are removed, the viscosity of the concentrated water is reduced, the evaporation and crystallinity of the concentrated water are improved, and the concentrated water enters the evaporation crystallization system to obtain a byproduct salt; the evaporated and crystallized mother liquor is returned to the pretreatment system to be mixed with the membrane concentration high-salt concentrated water for circular treatment, pollutants enriched in the mother liquor are removed, and the mother liquor can be continuously evaporated and desalted, so that zero mother liquor of the evaporation system is realized, and zero emission of the electroplating comprehensive wastewater is realized.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, and relates to a zero-discharge treatment system for comprehensive electroplating wastewater and a process thereof. Background technique [0002] Electroplating is the process of plating a thin layer of other metals or alloys on some metal surfaces by using the principle of electrolysis. It is a commonly used treatment process in industrial production and is widely used in aviation, aerospace, electrical appliances, decorative materials and other industries. Before electroplating, metal parts need to be degreased and derusted with acid and alkali, and then washed with a large amount of water for many times before they can enter the electroplating process; in addition, a plating solution containing heavy metal ions such as chromium, zinc, copper, nickel, etc. is used in the electroplating process. This makes the electroplating industry not only consume a lot of water, but also has a very ...

AI Technical Summary

Problems solved by technology

Advanced oxidation is not selective, and it will preferentially oxidize easily oxidizable and easily degradable organic matter in wastewater. Therefore, although the COD value of wastewater treated by advanced oxidation method may be significantly reduced on the surface, there will still be a large amount of refractory organic matter in the wastewater. , these refractory organic substances will be enriched after entering the evaporation system, and will cause problems such as scaling and blockage, large foam volume, and non-crystallization of salt in the evaporation system; single-effect evaporation + drying method, low-temperature evaporation method, and solidification method are all only Concentrating the pollutants in the electroplating wastewater does not treat the pollutants contained in the wastewater. Only a small amount of electroplating wastewater can be transitionally treated, which cannot fundamentally solve the pollution problem of electroplating wastewater; in addition, the above treatment methods still exist With the problems of large equipment investment and high treatment costs, a large amount of hazardous waste will be generated after treatment, and the cost of hazardous waste disposal will be higher, further increasing the burden on enterprises

Images