Methods and systems for treating alkaline chemical nickel plating wastewater

Abstract

The invention discloses a method and a system for treating alkaline chemical nickel plating wastewater. The method and the system can reduce the treatment cost of nickel-containing wastewater, improvethe cyclic utilization rate of nickel resources and enable nickel in the alkaline chemical nickel plating wastewater to reach the standard. The method comprises the following steps: 1) pumping wastewater with the pH value of 8.0-10 into a collecting tank; 2) heating the wastewater to 80-90 DEG C; 3) carrying out an electrolytic reaction by adopting an electro-deposition reactor; and 4) carrying out an autocatalytic reaction on nickel ions released after anodic oxidation in the nickel-containing complex state by taking metallic nickel, generated by reduction on a cathode, as an initiator to quickly reduce the nickel ions into elemental metal nickel on the cathode. The system adopts a multistage reaction device, so that the alkaline chemical nickel plating wastewater with high nickel and high phosphorus content can be quickly treated, the treated wastewater reaches the discharge standard specified by national standards, the nickel content of the treated wastewater is less than 0.1 ppm,and the TP value of the treated wasteater is less than 0.5 ppm. The method can replace the existing processes such as a chemical precipitation method, an ion exchange resin method, a membrane separation technology and the like.

Description

technical field [0001] The invention relates to the technical field of electroplating wastewater treatment, in particular to a method and system for treating nickel in alkaline electroless nickel plating wastewater up to standard. Background technique [0002] The electroless nickel plating technology uses a reducing agent to reduce and deposit nickel ions in the solution on the surface with catalytic activity to form a coating. Due to the advantages of no external power supply and uniform coating, it has been rapidly developed in my country. Electroless nickel plating can be divided into acidic electroless nickel plating and alkaline electroless nickel plating. Among them, alkaline electroless nickel plating mainly uses sodium hypophosphite as a reducing agent, and there are also components such as sodium citrate, ammonium chloride, and ammonium hydroxide in the plating solution. , The pH value of the plating solution is around 10. In the production process, after using th...

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Problems solved by technology

Using the existing technology to treat alkaline electroless nickel plating wastewater, on the one hand, it is impossible to realize the resource utilization of nickel, and the treatment of nickel is not up to standard. In the alkaline electroless nickel plating waste liquid, all nickel ions are complexed with organic matter, and single treatment The method cannot achieve nickel compliance and resource utilization

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