Effect of active hydroxylamine intermediates on improving cellulose protection and mass transfer in ozone bleaching of low-consistency pulp

•Active hydroxylamine intermediate (AHI) neutralizing HO· and HOO· to protect pulp viscosity in ozone bleaching.•AHI reduced cellulose decomposition and improved ozone selectivity by 16% and 38.9%, respectively.•AHI promoted mass-transfer rate of ozone in water.