Cr wastewater treatment
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Hello everyone! I would like to ask about the treatment method of chromium-containing wastewater and what are the products produced after treatment? Is it Cr(HO)3 s?
Ion exchange resin can be used to absorb chromium, and then acid and alkali regeneration can be used to recover chromium.
Domestic and foreign chromium-containing wastewater treatment methods that are widely used in industry include chemical reduction, ion exchange, adsorption, electrolysis, countercurrent rinsing-evaporation concentration and other methods. In recent years, methods such as biological methods, membrane separation methods, xanthate ester methods, photocatalytic methods, and tank-side circulation chemical rinsing have developed rapidly and become the focus of everyone's attention. Using different methods, the final product is different.
Adjust the pH value to 2-3 and add sodium bisulfite to reduce it to a redox potential of less than 300 mv. Add alkali to adjust the pH value to 8-9.
Is Cr in electroplating wastewater? Generally, Cr in electroplating wastewater exists in the form of +6 valence. It is generally reduced by using reducing agents (such as ferrous iron, sodium bisulfite, sodium metabisulfite, etc.) under acidic (pH-2-3) conditions, and then using alkali to adjust the pH to about 9 for precipitation. If ferrous iron is not used for reduction, the precipitation should be Cr(OH)3 precipitation. ； If ferrous iron is used for reduction, then chromium ferrite may be precipitated, and the specific molecular formula cannot be written in upper and lower subscripts.