Electroplating chromium-containing wastewater treatment system and treatment technology thereof

Abstract

The invention discloses an electroplating chromium-containing wastewater treatment system and a treatment technology thereof. The treatment system comprises a chromium-containing wastewater collectingsystem, a first pH adjusting system, a second pH adjusting system, a shallow air-floatation system, a temporary storage system, a sand filter system and an ultrafiltration system which are sequentially connected, wherein the shallow air-floatation system is further connected with a plate-frame pressure filtration system. According to the electroplating chromium-containing wastewater treatment system, electroplating chromium-containing wastewater is subjected to full treatment and up-to-standard discharge, chromium ions and other pollutants in the wastewater are effectively treated, damage ofdirect discharge to the environment and the ecosystem is avoided, the technology process is simple, a treatment effect is stable, the treatment investment cost is low, and discharge standards are met.

Description

technical field [0001] The invention belongs to the field of waste water treatment, and in particular relates to an electroplating chromium-containing waste water treatment system and a treatment process thereof. Background technique [0002] The electroplating industry is an important processing industry in my country, and the chromium-containing wastewater is a stream of wastewater that produces a large amount of water in the electroplating industry. The main component of chromium-containing wastewater is Cr 6+ , is the first type of pollutant, the most toxic, and the chromium-containing wastewater also includes a small amount of other metal ions such as Cu 2+ 、Co 2+ 、Ni 2+ , Fe 2+ , Ca 2+ 、Cr 3+ If one or more impurities are discharged directly without treatment, it will cause great harm to the environment and ecology. [0003] At present, for the treatment of chromium-containing wastewater, the commonly used treatment methods include chemical reduction, ion exchan...

AI Technical Summary

Problems solved by technology

The main component of chromium-containing wastewater is Cr 6+ , is the first type of pollutant, the most toxic, and the chromium-containing wastewater also includes a small amount of other metal ions such as Cu 2+ 、Co 2+ 、Ni 2+ , Fe 2+ , Ca 2+ 、Cr 3+ One or more impurities, if discharged directly without treatment, will cause great harm to the environment and ecology

[0003] At present, for the treatment of chromium-containing wastewater, the commonly used treatment methods include chemical reduction, ion exchange, and electrolysis. 6+ reduced to Cr 3 + , adding alkali to generate insoluble Cr(OH) 3 , and then removed by precipitation; the ion exchange method is to remove impurities and heavy metals in chromium-containing wastewater through the adsorption and regeneration of ion-exchange resins; Oxidation and reduction reactions occur on the two electrodes of the cathode to convert them into harmless substances, or use the electrode oxidation and reduction products to chemically react with harmful substances in the wastewater to form water-insoluble precipitates, and then achieve the purpose of separation and removal. Although the chromium-containing wastewater can be treated well, the effluent index is difficult to meet the Cr specified in Table 3 of the "Electroplating Pollutant Discharge Standard" (GB21900-2008). 6+ ≤0.1mg / L, total Cr≤0.5mg / L

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