The wastewater generated from the surface treatment of aluminum profiles is mainly acid-base wastewater, which contains a small amount of harmful anions and cations such as Ni2 +, Sn2 +, and F-. The treatment method is acid-base neutralization. Wastewater is generally acidic, and alkali must be added to neutralize it, and the pH value should be adjusted to about 7-8.5. At the same time, during the neutralization process, the cations Al3 +, Ni2 +, Sn2 +, Cr3 +, etc. all form hydroxide precipitates. The neutralized and precipitated wastewater is pumped into the coagulation tank by a pump, and the dissolved polyamide flocculant is pumped into the coagulation tank with a quantitative pump. After the coagulation, the wastewater enters the coagulation tank. Method, centrifugal sedimentation method, etc., the author believes that the centrifugal sedimentation method is more stable. After sedimentation, the supernatant liquid overflows from the upper overflow port and enters the drainage tank or reprocessing reservoir.

After the above treatment, the wastewater can be discharged up to standard. If the wastewater is to be reused, the wastewater at this time can be processed into the RO device after rough filtration to remove excess anions, organic matter, and the pH of the water at this time may be low. It can reach the reuse standard after being adjusted by anion and cation exchange device. The sludge produced by the precipitation is regularly discharged into the sludge tank, and is processed into industrial waste residue after being processed by a plate cake press or a belt dehydrator, and sent to an industrial waste residue treatment plant.