A treatment process for high-concentration waste liquid in the circuit board industry

Abstract

The invention provides a processing technology for a high-concentration waste liquid in circuit board industry. Considering from the point of wastewater resource recovery and final processing, nickel-containing wastewater, a nickel-containing waste liquid and a micro-etching solution are in early-stage processing for recovering valuable metals copper and nickel to obtain the waste liquor, the waste liquor is mixed into an acidized waste liquid; the acidic waste liquid, an alkaline waste liquid and an organic waste liquid are subjected to acid-precipitation coagulation sedimentation in a reaction pool, and a waste liquid discharged by a production workshop is fully utilized for self neutralization, so that a water-processing agent is saved, and the operation cost is reduced; and the acid-precipitation coagulation supernatant is subjected to high-grade oxidation for decomposing macromolecular organics and destroying complexes, sodium sulfide, sodium hydroxide and lime are added for coagulation sedimentation for removing heavy metals, the supernatant is subjected to hydrolysis acidification and biological oxidation, and obtained water reaches the standard and is discharged.

Description

Technical field [0001] The invention belongs to the field of wastewater treatment, and specifically relates to a high-concentration waste liquid treatment process in the circuit board industry. Background technique [0002] The circuit board industry will produce a large amount of high-concentration waste liquid in the production process, mainly including high-concentration alkaline organic waste liquid in the development and de-filming process, de-glue tank waste liquid in the copper sinking process, and acidic waste liquid in the pickling tank for surface treatment. And the micro-erosion waste liquid discharged from the micro-erosion tank and nickel-containing waste liquid. This kind of waste liquid has complex composition and high concentration. Although it only accounts for 3 to 5% of the total wastewater volume of the circuit board factory, it concentrates more than 70% of COD and Cu in the waste water discharged by the circuit board factory, and more than 90% of Ni and TP p...

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Problems solved by technology

The disadvantage is that the one-time investment cost is high, the operation cost is high, and the energy consumption is large

[0019] (4) Physical crystallization method, which uses the property that the solubility of copper sulfate decreases with the decrease of temperature, and uses the heat exchange system outside the tank to reduce the temperature of the micro-etching solution so that the copper ions in the micro-etching solution crystallize and precipitate in the form of copper sulfate. After filtration, the micro-etching solution is returned to the production line for reuse. This method does not change the composition of the micro-etching solution. The main disadvantages of this method are high energy consumption and low efficiency. Strictly speaking, the recycled copper sulfate product is also a hazardous waste. Not very feasible

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