Application of Membrane Electrolyzer
A membrane separation method for simultaneous electrodialysis and electrolysis using the anode and cathode of Membrane Electrolyzer.Depending on the properties of the diaphragm used, it can also be divided into non-selective ion through membrane electrolysis and selective ion through membrane (ion exchange membrane) electrolysis.
In recent years, some countries have used Membrane Electrolyzer to treat industrial waste water in order to protect the environment and recycle resources.Membrane Electrolyzer is mainly used in two areas:
1. Recycling heavy metals
Industrial wastewater is chemically treated, in which toxic heavy metal ions are converted into insoluble substances such as hydroxides, carbonates, oxides, sulfides, etc. and removed after precipitation.The sediment mud contains toxic heavy metals which can be recovered by Membrane Electrolyzer.
Put the mud into the anode chamber of Membrane Electrolyzer, and place the appropriate electrolyte into the cathode chamber to electrolyse using insoluble anodes.
In the anodic reaction of Meembrane Electrolyzer, free acids are used to dissolve the mud, so the pH of the electrolyte remains the same.Metal ions produced by mud dissolution are moved to the cathode chamber through the diaphragm and precipitated by reduction to metal at the cathode.The method of recovering metals using Membrane Electrolyzer is efficient.The recovery of nickel, copper, zinc and chromium from sediment slurry from electroplating wastewater was successful in Japan in 1971.
2. Recycled chrome plating waste liquid
Chromium plating is mainly made of chromium anhydride.The hexavalent chromium concentration decreases and the trivalent chromium concentration increases due to the accumulation of impurity cations.When trivalent chromium and impurity ions reach a certain concentration, the electroplating solution becomes invalid.If trivalent chromium is oxidized to hexavalent chromium and metal impurities are removed, the waste plating solution can be regenerated and reused.
Japan has been experimenting with the recovery of chrome plating wastes from Membrane Electrolyzer with diaphragms such as coarse ceramic plates since 1964.China has also carried out a series of studies in this field and has achieved very good results.