A purification treatment process for circuit board etching waste liquid

Abstract

The invention provides a purification treatment process of circuit board etching waste liquid. According to the purification treatment process, a two-step pH value regulation process comprising a pre-settling process is utilized, so that high-concentration organic matters can be effectively removed, and a relatively good purification treatment effect is achieved; furthermore, treatment temperature gradually increases in two settling treatment processes, and therefore the problem that an adsorption effect is affected by the re-accumulation of decomposed organic matter particles can be effectively avoided; flocculating settling materials of different properties and parameters are selected with a clear target in different settling stages, so that a relatively effective organic matter removal effect is achieved; by reasonably setting the pH value during the settling, the organic matters is well decomposed; the pH value is adjusted by virtue of a special acid solution, so that the decomposing adsorption effect of the organic matters is achieved; a proper amount of hydrogen peroxide is added to further decompose the organic matters, so that the organic matters can be well adsorbed and settled.

Description

technical field [0001] The invention relates to a treatment process for industrial waste liquid, in particular to a purification treatment process for circuit board etching waste liquid. Background technique [0002] In recent years, with the rapid development of my country's electronics industry, the manufacturing consumption of circuit board products as the basis of the electronics industry has also increased sharply. As of 2005, my country has become the world's largest production base of printed circuit boards, and there are a large number of The printed circuit boards of electronic products will be produced and assembled in my country, and the annual output of PCBs exceeds 200 million m 3 , and in the manufacturing process of circuit boards, it will produce a large amount of alkaline and acidic etching waste liquid. These etching waste liquids have the characteristics of various types, high toxicity, and strong corrosion. If it is treated and discharged at will, it will...

AI Technical Summary

Problems solved by technology

[0003] Since these etching waste liquids usually have high COD (Chemical Oxygen Demand) and BOD (Biochemical Oxygen Demand), a very complicated waste liquid treatment system is required to treat these waste liquids to obtain harmless liquids that are allowed to discharge up to standards. and high processing costs

The more common treatment methods now mainly include the following two types: one is the comprehensive biological treatment technology through several steps such as adding acid-activated carbon adsorption-biological treatment. There is a large amount of organic matter in the waste liquid, and then the decomposed organic matter is adsorbed and settled, and then other methods such as biological treatment are used to further reduce COD and BOD, and then the solution is neutralized with alkali, and the solution is diluted to continue to reduce the concentration of organic matter to meet the emission requirements. This process requires a large amount of dilution water, whose volume is even more than 10 times that of the waste liquid to be treated, and requires large-scale treatment equipment, which undoubtedly greatly increases the treatment cost. At the same time, the efficiency of biological treatment is very low, and it is difficult to reduce COD to degree of satisfaction

The other is to use a reverse osmosis membrane to separate, but this treatment method is difficult to concentrate the concentration of organic matter in the concentrated waste liquid to a very high degree, and its limit concentration ratio can only make the concentration of the concentrated waste liquid to be The treatment concentration is about 5 times that of the raw liquid, so one-fifth of the concentrated waste liquid cannot be treated and is discarded and difficult to discharge. At the same time, the reverse osmosis membrane treatment system is more expensive and difficult to meet the growing treatment demand