Nickel cyanide-containing wastewater treatment technology

Abstract

The invention discloses a nickel cyanide-containing electroplating wastewater treatment technology and aims at providing an electroplating wastewater treatment method which has the advantages of reasonable flow, concise process, effective elimination of cyanide ions in wastewater, strong treatment ability and smooth and efficient treatment process. The nickel cyanide-containing electroplating wastewater treatment technology comprises the following steps: firstly adding acid or alkali to adjust the pH value according to the acid-base property of the wastewater; adding hydrogen peroxide; performing oxidation breaking of cyanide ions in a weak-alkali condition; after 20min of reaction, adding appropriate sodium pyrosulfite to reduce the excess hydrogen peroxide; reducing the bubbles generated by the decomposition of residual hydrogen peroxide and stirring the wastewater so that the sludge floats upward and is hard to precipitate; adding alkali to adjust the pH value; enabling the treated wastewater to enter a collection tank and then a coagulation tank, and adding a coagulation drug for coagulation; enabling the coagulated wastewater to enter a flocculation tank, and adding a flocculation drug for flocculation; and removing the flocculated particles in the flocculated wastewater by a flocculation removal device, wherein the wastewater can be directly discharged. In the invention, the hydrogen peroxide is adopted for cyanogen breaking instead of traditional sodium hypochlorite, so that the oxidation of nickel is avoided, the drug consumption is reduced, and the salt content in the finally discharged wastewater is greatly reduced correspondingly.

Description

technical field [0001] The invention belongs to the technical field of waste water treatment, in particular to a process for treating waste water containing nickel cyanide. Background technique [0002] The sources of electroplating wastewater are generally: (1) plating cleaning water; (2) waste electroplating solution; (3) other wastewater, including washing the floor of the workshop, scrubbing plate washing water, condensed water from ventilation equipment, and leakage from plating tanks. Or various baths and drains of "running, popping, dripping, and leaking" caused by 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 methods and other factors. The water quality of electroplating wastewater is complex, and the cyanide ions in it are highly toxic substances that are carcinogenic, teratogenic, and mutagenic. They m...

AI Technical Summary

Problems solved by technology

The water quality of electroplating wastewater is complex, and the cyanide ions in it are highly toxic substances that are carcinogenic, teratogenic, and mutagenic. They must be properly treated so that their content reaches the standard before they can be discharged into wastewater

[0003] Nickel cyanide wastewater belongs to electroplating wastewater that is difficult to dispose of. Because cyanide ions are highly toxic, the cyanide ions must be oxidized and broken first. However, the current electroplating wastewater treatment methods often use sodium hypochlorite to break cyanide under alkaline conditions. However, for nickel cyanide wastewater, sodium hypochlorite can not only oxidize cyanide, but also oxidize divalent nickel ions into trivalent nickel, which not only leads to unreasonable consumption of sodium hypochlorite, but also produces high nickel hydroxide which is fine particles and difficult to precipitate. It causes the wastewater to turn black and affects the quality of the effluent. There are still obvious deficiencies and deficiencies in the thoroughness, efficiency, and convenience of the treatment.