The passivator of potassium dichromate is one of the main electrolysis manganese passivation technologies in China. The biggest problem of hexavalent chromium passivation is chromium emission. The end-pipe treatment of Cr-containing effluents can be understood as detoxification and precipitation. Here the highly toxicity Cr(Ⅵ) is reduced to low toxicity Cr(Ⅲ) . In alkaline conditions, Cr (Ⅲ)is precipitated in the type of chromium hydroxide and produce chromium residue. The landfill of Chromium residue is a big problem to environment safety. The measures of clean process were reviewed around with emission reduction of Cr.