Electroplating pre-treatment technology of cyanide-containing wastewater

Abstract

The invention discloses an electroplating pre-treatment technology of cyanide-containing wastewater and belongs to the technical field of sewage treatment. The electroplating pre-treatment technologyof the cyanide-containing wastewater comprises the following steps: carrying out stagnation and flow distribution on electroplating wastewater, carrying out suspension complex breaking treatment, carrying out turbid liquid cyanide breaking pre-treatment, carrying out turbid liquid dispersion and cyanide breaking, filtering cyanide breaking wastewater, and neutralizing treated wastewater. The stepof carrying out the stagnation and flow distribution on the electroplating wastewater comprises the steps of discharging the electroplating wastewater into a primary sedimentation tank and carrying out the stagnation and flow distribution; one end of the sedimentation tank is connected with wastewater drainage equipment, so that primary treatment on the electroplating wastewater to be subjected topurification treatment can be realized and the concentration of cyanide in the electroplating wastewater is reduced; meanwhile, the electroplating wastewater containing the cyanide is conveniently combined with a neutralization reaction agent, the reaction effect of neutralization reaction is enhanced and the reaction waiting time of the neutralization reaction agent is reduced, so that the treatment efficiency of the wastewater is improved; and meanwhile, the equipment cost and operation cost for breaking the cyanide by adopting an electrolysis treatment technology are reduced.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a pretreatment process for electroplating wastewater containing cyanide. Background technique [0002] The sources of electroplating wastewater are generally: plating cleaning water, waste electroplating solution, washing workshop floor, scrubbing plate washing water, ventilation equipment condensate, and various bath liquids and drainage caused by plating tank leakage or improper operation and management. The water quality and quantity of electroplating wastewater are related to the process conditions of electroplating production, production load, operation management and water use methods and other factors. The water quality of electroplating wastewater is complex, and its composition is difficult to control. It contains heavy metal ions such as chromium, cadmium, nickel, copper, zinc, gold, silver, and cyanide, etc. Some of them are highly toxic substances that ar...

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Problems solved by technology

[0003] In the process of treating electroplating wastewater in existing factories, all these invalid bath solutions are generally discarded. These discarded solutions of various concentrations generally have a high concentration of heavy metal ions and a lot of accumulated impurities. Not only the types of pollutants are different , and the concentration of the main pollutants, the concentration of other metal impurity ions and the solution medium also often have larger differences. These methods all need to use the reaction tank to carry out reaction neutralization when carrying out the wastewater treatment of cyanide. In the prior art In order to fully react in the neutralization reaction, it is necessary to wait for a long time for the neutralizer added to the reaction tank to fully volatilize and react. This process needs to wait for a long time, resulting in extremely low wastewater treatment efficiency. Higher, not suitable for the secondary alkaline chlorination method to break cyanide, generally need to use electrolytic treatment technology to break cyanide, and then the wastewater containing cyanide can be treated, which requires high investment in equipment construction and operation

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