Mercury removal from effluents - by dissolving with chlorine and pptg in sulphide form

摘要

Purificn. of effluents from chlorine-alkali electrolysis, paper prodn., etc. is improved in that the residual Hg remaining in the effluents after a mechanical coarse sepn. is dissolved with chlorine (gaseous, or in the form of hypochlorite); the excess chlorine is reacted with a reducing agent (pref. NaHSO3 or Na2SO3); Hg is pptd. as sulphide, the sulphide is sepd. by filtration and roasted and the resulting Hg vapour is condensed. Hg contamination of effluents is reduced to 0.1 ppm.