Method for purifying waste water and recovering waste materials on line in electroplating and chemical plating processes

Abstract

The invention provides a method for purifying waste water and recovering waste materials on line in electroplating and chemical plating processes. The method comprises the following steps of: directly arranging a capacitance deionizer in a water washing device on a production line to adsorb various negative ions and positive ions in waste water during charging a battery so as to purify the waste water; and then releasing and recovering waste materials through electrode discharge so as to realize zero release of pollutants. The invention ensures that the capacitance deionization method is suitable for the manufacturing processes of various electroplating or chemical plating products through the optimization of process parameters. Through on-line purification and recycle of washing water, the burden of the traditional waste water treatment system is obviously reduced, meanwhile, the quality of plating pieces is guaranteed because the water quality of the washing water is obviously improved, and the classified recovery of waste materials can be achieved. The method can also obviously reduce the COD in the waste water and has wide application prospect in the fields of electroplating and chemical plating.

Description

technical field [0001] The invention belongs to the technical field of water treatment, and in particular relates to a method for on-line purification of wastewater generated in electroplating or chemical plating processes and recovery of useful substances in the wastewater by using a capacitive deionization method. Background technique [0002] As a surface treatment technology with a long history of development, electroplating and chemical plating technology not only play an important role in traditional industries, but also in many modern high-tech industries, such as electronics, microelectronics, communications, information technology, aerospace and other fields is also essential. But on the other hand, electroplating and electroless plating are recognized as a high-pollution industry. Although they produce less wastewater than many other industries, such as papermaking, printing and dyeing, and chemical industry, they still produce Wastewater often contains a large am...

AI Technical Summary

Problems solved by technology

However, the treatment and recovery technology adopted in this patent has the following defects: (1) what this technology adopts is that ion exchange resins are used to adsorb heavy metal cyanides, and its principle is to utilize ion exchange resins to have fixed charged groups. Therefore, it has great restrictions on the types of pollutants that can be adsorbed and the combination of pollutant mixtures in the system. For example, it is limited to the treatment of wastewater containing cyanide and heavy metals, and cannot be widely used. Treat various types of electroplating or electroless plating wastewater; (2) The ion exchange resin used in this technology has a small adsorption capacity and needs to be regenerated more frequently, and the regeneration process needs to be added with a regenerant, so the regeneration process cannot be completed in the same system , the operation is inconvenient, which is not conducive to the application of the online purification process; (3) the use of ion exchange resins for adsorption often requires the consumption of acid or alkali, and the regeneration process after adsorption requires the application of electric current, which consumes a lot of resources, and the addition of other substances prone to secondary pollution

But all these patents are aimed at how to improve the CDI device itself, without analyzing and explaining how these devices treat different sources of wastewater

Although scientifically speaking, CDI technology can adsorb any form of anions and cations, but the types of anions and cations and other pollutants contained in different wastewater are very different, so a "universal" CDI device for all wastewater is a fact above is difficult to achieve

At present, CDI technology is mostly used for desalination. There is no report on whether it can be applied to wastewater treatment of electroplating or electroless plating, and how to apply this technology in wastewater treatment of electroplating or electroless plating.