Abstract: The invention described in the specification is a method for removing hydrogen sulfide, volatile mercaptans and methyl sulfides from a paper mill condensate stream. In the method, carbon dioxide is injected into the condensate stream under pressure and the pressure of the resulting CO.sub.2 -enriched condensate is reduced rapidly to a pressure sufficient to cause hydrogen sulfide and volatile mercaptans to pass from the CO.sub.2 -enriched condensate to a gas phase. The gas phase containing hydrogen sulfide and mercaptans may then be recycled or burned and the treated condensate may be recycled for pulp washing. The method is very cost effective and can be easily retrofitted into existing paper mill systems without significant capital expenditures or production down time.