Disclosed is a method for controlling microbial growth in an aqueous
system containing sulfite and/or bisulfite residues by addition of a
peroxy compound at a pH of greater than 5. Also disclosed is a method for
stabilizing an active halogen biocide in an aqueous system containing
peroxide residues by addition of an N-hydrogen compound to the active
halogen biocide before combining it with the peroxide containing aqueous
system. Further disclosed is an optimized papermaking biocide program
consisting of initially treating sulfite bleached pulp with peroxide
followed by application of an N-hydrogen-stabilized active halogen
compound to the paper producing white waters and an analytical method for
determining peroxide concentrations in aqueous systems in the presence of
sulfite and/or bisulfite.