SETT ATT BEHANDLA AVLOPPSVATTEN INNEHALLANDE CYANIDER, FORMIATER OCH HALOGENID AV METALL ELLER AMMONIAK OCH ANVENDNING AV SETTET FOR ATT BEHANDLA AVLOPPSVATTEN FRAN VATTENKYLNINGSSTEGET I EN PROCESS FOR FRAMSTELLNING AV

摘要

A method is provided for the treatment of a waste water stream characterized by having toxic and corrosive properties due to the presence of a cyanides formates and a halide of a metal or ammonia comprising adding a ferrous ion to said waste water to convert the cyanides to iron cyanides, adding a base to said waste water until the pH of said waste water is adjusted to the range from about 9 to 11 to precipitate a sludge containing said iron cyanides, feeding said waste water to a biological reactor to convert said formates to carbon dioxide and a biological residue and recovering an environmentally upgraded waste water stream from said biological reactor.