Principle and method of wastewater treatment for aluminum profile surface treatment
Source：Jiangyin New Sulv Technology Co., Ltd. Release time：2022-11-14 10:49:20 Author：136
The wastewater generated by the surface treatment of aluminum profiles is mainly acid-base wastewater, containing a small amount of harmful anions and cations such as Ni2+, Sn2+, F-, etc. The treatment method is acid-base neutralization. The wastewater is generally acidic, and it must be neutralized with alkali, and the pH value should be adjusted to about 7-8.5. At the same time, cations Al3+, Ni2+, Sn2+, Cr3+, etc. all form hydroxide precipitation during the neutralization process. The neutralized and precipitated wastewater is pumped into the coagulation tank, and at the same time, the dissolved polyamide flocculant is injected with a quantitative pump to coagulate the wastewater. After the coagulation, the wastewater enters the sedimentation tank. The precipitation methods include inclined plate sedimentation, air flotation The author believes that the centrifugal precipitation method is relatively stable in use. After precipitation, the clear liquid overflows from the upper overflow port and enters the discharge tank or reprocessing reservoir.
The wastewater after the above treatment can be discharged up to the standard. If the wastewater is to be reused, the wastewater at this time can be processed by the RO device after rough filtration to remove excess anions, cations and organic matter. The pH value of the water at this time may be low. , can be adjusted by the anion and cation exchange device to reach the reuse standard. The sludge produced by precipitation is regularly discharged into the sludge tank, and after being processed by a plate cake press or a belt dehydrator, it becomes industrial waste and sent to an industrial waste treatment plant.