Processing technology of electroplating wastewater

Abstract

The invention discloses a processing technology of electroplating wastewater; the processing technology comprises the following steps: step 1, collecting chromium-containing electroplating wastewater and cyanide-containing electroplating wastewater; step 2, reducing chromic acid in the chromium-containing electroplating wastewater by virtue of cyanide in the cyanide-containing electroplating wastewater, to obtain comprehensive electroplating wastewater; step 3, adding an alkaline solution into the comprehensive electroplating wastewater, and adjusting the pH value of the comprehensive electroplating wastewater to 7-8, to obtain a primary precipitate; step 4, filtering the primary precipitate to obtain a supernatant; step 5, adding a ferrous salt solution and hydrogen peroxide into the supernatant, and respectively carrying out reaction to remove the remaining chromic acid and cyanide; step 6, adding the alkaline solution again, and adjusting the pH value of the supernatant to 9-10, to obtain a secondary precipitate; and step 7, removing the secondary precipitate. The processing technology is optimized, the purification efficiency is improved, the investment cost is reduced, the resource waste is saved, and the effects of treatment of wastes with wastes and resource utilization are realized.

Description

technical field [0001] The invention relates to a wastewater purification process, in particular to a treatment process for electroplating wastewater. Background technique [0002] The electroplating industry is an indispensable link in my country's national economy, involving various fields such as national defense, industry, and life. The phenomenon of large demand has also caused the excessive development of the electroplating industry, and a large number of electroplating factories have been built. Waste water and waste liquid discharged from electroplating factories (or workshops), such as rinsing water for plating parts, waste tank liquid, cooling water for equipment, and water for flushing the ground, etc. Due to many types of plating, cumbersome process, complex water quality, and difficult control of components, electroplating wastewater mainly contains heavy metal ions such as chromium, cadmium, nickel, copper, zinc, gold, silver and cyanide, etc. These electroplat...

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Problems solved by technology

[0004] 1. The process is complex. Not only does it need to classify and separate the wastewater during pretreatment, but also has higher requirements for process parameters and process environment in the subsequent treatment process;

[0005] 2. The purification efficiency is not high, the purification effect is not good, and it is difficult to meet the national electroplating wastewater discharge standard. If it is not handled properly, the heavy metals in the sludge will easily cause secondary pollution to the environment.

[0006] 3. The input cost is extremely high, more treatment steps and treatment devices are required, and a lot of chemicals are needed in the treatment process. The heavy metals in the wastewater are easy to waste. The treatment process so far cannot realize the transformation of waste into treasure. The effect of resource regeneration and efficient use;

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