1. Sodium metabisulfite is a reducing agent, which is used to treat chromium-containing wastewater in sewage treatment.
2. Chromium-containing wastewater must be treated separately according to national standards, and it cannot be discharged to the integrated pool, and the hexavalent chromium concentration must not be higher than 0.1.
3. Therefore, the dropping point of sodium metabisulfite is in the raw water of chromium-containing wastewater to reduce hexavalent chromium to trivalent chromium and then precipitate