초록 ▼

A process for the biological treatment of a spent caustic solution containing sulphides is disclosed, wherein the solution is introduced into an aerobic reactor containing sulphide-oxidising bacteria, and the sulphides are partly converted to elemental sulphur and partly to sulphate by controlling t

A process for the biological treatment of a spent caustic solution containing sulphides is disclosed, wherein the solution is introduced into an aerobic reactor containing sulphide-oxidising bacteria, and the sulphides are partly converted to elemental sulphur and partly to sulphate by controlling the redox potential in the reactor at a value below -300 mV (against an Ag/AgCl reference electrode), or below -97 (against a H.sub.2 reference electrode). Also disclosed is process for the biological treatment of an aqueous solution containing sulphides and/or mercaptans in an aerobic reactor, wherein the solution is treated in the presence of bacteria of the new species Methylophaga sulfidovorans.

대표청구항 ▼

[ We claim:] [1.] Process for the biological treatment of a spent caustic solution having a pH of at least 11 and containing sulphides, wherein the solution is subjected to sulphide-oxidising bacteria in an aerobic reactor, characterised in that the sulphides are partly converted to elemental sulphu

[ We claim:] [1.] Process for the biological treatment of a spent caustic solution having a pH of at least 11 and containing sulphides, wherein the solution is subjected to sulphide-oxidising bacteria in an aerobic reactor, characterised in that the sulphides are partly converted to elemental sulphur and partly to sulphate, the sulphate production resulting in a pH lowering to between 6 and 9, by controlling the redox potential in the reactor at a value between -300 and -360 mV (against an Ag/AgCl reference electrode). [7.] Process for the biological treatment of an aqueous solution containing sulphides and/or mercaptans wherein the solution is subjected to sulphide-oxidising bacteria in an aerobic reactor, characterised in that the solution is subjected to bacteria of the species Methylophaga sulfidovorans.