An X-ray photoelectron study of the reaction of metal ions with borohydride under reductive bleaching conditions

Metal ions in mechanical pulp brightening systems affect hydrogen peroxide bleaching by accelerating decomposition of H 2 O 2 and by forming colored metal complexes with pulp. The authors have examined the effect of borohydride on Fe(III), Cu(II) and Mn(II), the predominant ions found in mechanical pulp and the associated white water. X-ray photoelectron spectroscopy was applied to determine the oxidation states of the metal ions in the precipitates.