Treatment method of electroplating rinsewater

Abstract

The invention relates to a treatment method of electroplating rinsewater which is treated by adopting an electrodeionization membrane stacking device. An electrodeionization membrane stack comprises five chambers which are sequentially separated by an anion exchange membrane, a cation exchange membrane, a bipolar membrane, an anion exchange membrane from a negative electrode to a positive electrode and the five chambers include an electrode chamber, a concentration chamber, a first desalting chamber, a second desalting chamber and a positive electrode chamber in sequence. The concentration chamber and the first desalting chamber are filled with macroporous strong-acid cation exchange resin, and the second desalting chamber is filled with macroporous strong-basic anion exchange resin. The rinsewater to be treated flows through the first desalting chamber and the second desalting chamber sequentially to obtain desalted pure water by cation and anion removing processes; and cations are transferred to the concentration chamber via the first desalting chamber and anions are transferred to the concentration chamber via the second desalting chamber, the positive electrode chamber and the negative electrode chamber in sequence, thus, concentrated water current is obtained. H+ and OH- ions which are products of bipolar membrane water dissociation respectively carry on high-efficiency real-time dynamic regeneration on the cation / anion exchange resin filled in the two desalting chambers. The wastewater treatment technology avoids scaling inside the electrodeionization membrane stack, does not need acid-alkali regeneration ion exchange resin in the treatment process, has no secondary pollution, and is beneficial to realizing the harmless and reclamation treatment.

Description

technical field [0001] The invention relates to a treatment method for electroplating and rinsing wastewater, in particular to an electrodeionized water purification method with a bipolar membrane, which belongs to the wastewater treatment technology. Background technique [0002] Electroplating wastewater is a major heavy metal wastewater, of which more than 80% belong to electroplating rinse wastewater, and its typical concentration of heavy metal ions is tens to hundreds of mg·L -1 . Traditional heavy metal wastewater treatment methods include chemical methods (including chemical precipitation and electrolysis), ion exchange methods, and membrane separation technologies such as electrodialysis and reverse osmosis. Chemical methods, electrodialysis and reverse osmosis are mostly used to treat wastewater containing high concentrations of heavy metal ions. The quality of the produced water is still low, and it is difficult to directly meet the industrial discharge standards...

AI Technical Summary

Problems solved by technology

Since the anions and cations in the desalination chamber will respectively migrate towards the positive and negative electrodes and enter the concentration chamber, setting up such a single resin layer section at different parts of the same desalination chamber will promote the formation of corresponding charged ions. migration, but at the same time it also hinders the migration of another ion with the opposite charge in the resin layer

This not only increases the resistance of the membrane stack, but also easily forms heavy metal hydroxide scale deposits in the concentration chamber and electrode chamber, which is not conducive to the stable operation of the process

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