Electroplating integrated wastewater treatment method

Abstract

The invention relates to an electroplating integrated wastewater treatment method which is characterized by comprising the following steps: electroplating integrated wastewater flows through an adjustment tank, reductant is added in a reduction tank to fully reduce the Cr<6+> in wastewater to Cr<3+>, then electroplating wastewater treatment agent is added in a reaction tank until the pH value of the wastewater in the reaction tank is 8; the wastewater enters a precipitation tank to precipitate, the sludge in the precipitation tank is squeezed, and the supernatant in the precipitation tank and the filtrate obtained through the squeezing of sludge are reused or directly discharged. The electroplating wastewater treatment agent comprises the following components in parts by weight: 50-90 parts of alkaline substance, 10-30 parts of oxidant, 1-10 parts of trapping agent and 1-2 parts of coal gangue, wherein the alkaline substance consists of one or more of NaOH, KOH or Ca(OH)2; the oxidant consists of NaClO3, Ca(ClO)2 and CaO2, and the trapping agent consists of Na2S and Al(OH)3. The method is convenient to operate; the treatment process is simplified, the treatment cost is reduced, the floor area and labor are reduced, the investment is saved; the qualification rate of discharge water is more than 99.9%; and wastewater treatment can be performed continuously and stably.

Description

Technical field [0001] The invention is the field of industrial electroplating wastewater treatment, which involves a comprehensive wastewater treatment method such as acid -alkaline wastewater, chrome -plated wastewater, nickel -plated wastewater, galvanized wastewater, and copper -plated wastewater. Background technique [0002] The electroplating comprehensive wastewater generated by the electroplating industrial park generally contains acid -base wastewater, chrome -plated wastewater, nickel -plated wastewater, galvanized wastewater, copper -plated wastewater, etc. The pH value of its ionic form is complex, the colloid shape is not easy to precipitate, and the pH values of various metal ions precipitate are different.And it is difficult to separate the solid liquid after the metal ions are precipitated.At present, there are many comprehensive treatment methods used in electroplating industrial parks, such as chemical method, ion exchange method, electrolytic interpretation me...

AI Technical Summary

Problems solved by technology

At present, there are many comprehensive wastewater treatment methods used in electroplating industrial parks, such as chemical methods, ion exchange methods, electrodialysis methods, electrolytic methods, etc. Among them, chemical methods are more commonly used methods, which are added to wastewater containing hexavalent chromium ions. Reducing agent (such as ferrous sulfate, sodium sulfite, iron powder, sulfur dioxide, etc.), reducing hexavalent chromium to trivalent chromium, then adding sodium hydroxide, a wastewater treatment agent, to adjust the pH value of wastewater, and graded precipitation of heavy metal ions in wastewater (electroplating The pH value of the precipitate formed by the heavy metal ions in the wastewater is different, especially the zinc ion can only be precipitated under the condition of pH>9), and finally it is necessary to adjust the pH value of the supernatant after precipitation by adding acid before it can be discharged. There are many facilities, large land occupation, high cost and operation management difficulties, long treatment process, large investment, large energy consumption, high labor intensity of workers, high operating costs, and difficulties in the stable operation of wastewater treatment and standard discharge.

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