Three-stage biological comprehensive treatment method for printed circuit board waste water

Abstract

The present invention discloses a three-stage biological comprehensive treatment method for printed circuit board (PCB) waste water. The method comprises a three-stage biological treatment process, and is characterized in that: the method is performed by the following steps that: (1) PCB mixing waste water is poured into a reaction tank 1, the pH value is adjusted to 2.7-3.2 with sulfuric acid, ferrous sulfate is added, the waste water is transferred to a flocculation tank 1, the pH value is adjusted to more than 7 by an alkali solution, a flocculating agent is added to carry out precipitation, and the waste water and the resulting precipitation are transferred into a precipitation tank; (2) the waste water is poured into a neutralization tank, a nitrogen source is added, the pH value is adjusted to 6.8-7.2, the resulting waste water enters an aeration tank to carry out biodegradation, and flows through a precipitation tank 2; (3) the waste water is poured into a reaction tank 2, the pH value is adjusted to 8.8-9.2, the flocculating agent is added, the waste water is introduced to a precipitation tank 3, and then is discharged. With the present invention, the grinding plate waste water, the printing ink waste water, the copper-containing waste water and the electroplating waste water can be simultaneously treated, the treatment efficiency of the organic compound with high complex copper is high, and the cost is low.

Description

technical field [0001] The invention relates to a treatment method for industrial waste water produced in the process of producing printed circuit boards, in particular to a three-stage biological comprehensive treatment method for printed circuit board waste water. Background technique [0002] The production of printed circuit boards is mainly to remove excess copper on the copper clad laminates and form circuits. As the circuit boards become more and more fine and small, the processing precision is increasing day by day, which makes the production of printed circuit boards more and more complicated. The production process has dozens of Each process has chemical substances entering the wastewater. The types of circuit board wastewater are complex and the pH changes greatly. According to the nature of the wastewater discharged from each production process, it can be divided into the following five categories: (1) Board grinding wastewater: it comes from the cutting and grin...

AI Technical Summary

Problems solved by technology

In the production process of printed boards, sulfuric acid, hydrochloric acid, nitric acid, sodium hydroxide, and various commercial liquids such as etching solutions, chemical plating solutions, electroplating solutions, activation solutions, pre-dipping solutions, etc. are used. Most of the components are known, and there are a small amount of unknown components, which makes wastewater treatment more complicated and difficult

[0004] At present, there are two main problems in the treatment of printed circuit board wastewater: one is the poor removal effect of wastewater containing complexed copper; the other is poor biodegradability of high-concentration organic wastewater

At present, most water treatment processes adopt a classified treatment method for circuit board wastewater, such as ink wastewater containing high concentrations of organic matter, complex copper wastewater, electroplating wastewater, etc., which will undoubtedly greatly increase the treatment cost.

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