Method for processing waste water generated by extracting copper oxide from acidic corrosion waste fluid

Abstract

The invention discloses a method for processing waste water generated by extracting copper oxide from acidic corrosion waste fluid. The processing method comprises the following steps of: (1) extracting the copper oxide from the acidic corrosion waste fluid through strong alkaline solution, and generating waste water; (2) adopting cationic resin to carry out initial treatment; (3) adding sodium hypochlorite to remove ammonia nitrogen; (4) conveying to a first reaction pond, adding aluminium polychlorid to remove heavy metal ions, then conveying to a second reaction pond, and adding polyacrylamide to carry out sedimentation; and (5) in a settling pond, setting and layering suspending matters in waste water, conveying clear water on an upper layer into an air floating machine to remove the suspending matters, and discharging. According to the processing method, not only can the content of copper ions and ammonia nitrogen in the waste water can be reduced, but also COD (Chemical Oxygen Demand) can be greatly reduced, the processing effect for waste water with low COD content is good, and continuous processing of waste water generated by extracting the copper oxide from the acidic corrosion waste fluid can be realized.

Description

technical field [0001] The invention belongs to the field of wastewater treatment, and in particular relates to a method for treating wastewater after extracting copper oxide from acidic etching waste liquid. Background technique [0002] The acidic or alkaline etching waste liquid of the PCB circuit board factory contains about 10% copper by mass. In order to save resources and reduce the pressure of post-processing, the copper in the etching waste liquid is usually recycled. Recycled forms include copper salts such as copper oxide, copper sulfate, and copper chloride. However, waste water will still be produced after copper recovery, which contains a small amount of copper and a relatively large amount of ammonia nitrogen, which must be further treated before being discharged. [0003] Traditional ammonia nitrogen wastewater treatment mainly adopts alkali stripping method, evaporation concentration method, resin exchange method, biochemical method and so on. Because a la...

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Problems solved by technology

However, during the treatment process, hydrogen sulfide gas is easily generated due to the addition of sodium sulfide in the copper precipitation process, and a small amount of sulfide will still remain in the wastewater after copper precipitation

During the biochemical treatment of the treated wastewater to reduce the ammonia nitrogen content, due to the high content of sodium salts in the wastewater, the bacterial population is extremely easy to die during the biochemical process

This two-step method of treating wastewater not only increases the exhaust gas emission of the wastewater treatment workshop, but also consumes more manpower and material resources, which increases the cost

And in the ammonia nitrogen treatment stage, due to the death of the bacterial flora, the ammonia nitrogen treatment of the wastewater cannot meet the standard

[0005] Existing recovery of copper oxide from acidic etching waste liquid usually involves adding a strong base such as potassium hydroxide or sodium hydroxide, or a mixture thereof with a base such as sodium carbonate or sodium bicarbonate, see (JP8012327 or CN201110396253.1) After copper oxide is recovered by this method, the copper content in the wastewater is about 10-20mg / L, and the ammonia nitrogen content is about 60-500mg / L, which fails to meet the discharge standard and must be treated before it can be discharged. From the existing methods, all There are problems such as high cost and poor adaptability. Therefore, it is necessary to study a new post-treatment method to treat the waste water after copper oxide is extracted from acidic etching waste liquid.

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