The present invention relates to a method of generating chlorine dioxide from chlorite salts in the presence of an iron ion-containing complex, a method of treating a substrate with a chlorine-containing oxidant in the presence of an iron ion-containing complex and related aqueous media, kits and compositions.

Process for the delignification and bleaching of pulp, comprising a first bleaching stage with hydrogen peroxide in the presence of a molybdate or tungstate in an acidic aqueous mixture; subsequent to the first bleaching stage, a second bleaching stage with hydrogen peroxide in an alkaline aqueous mixture; and, subsequent to the second bleaching stage, a third bleaching stage with hydrogen peroxide in the presence of a molybdate or tungstate in an acidic aqueous mixture.

The present invention relates to compositions for use in an aqueous pulp bleaching process, comprising one or more alkaline earth metal oxides and/or one or more alkaline earth metal hydroxides; one or more alkaline earth metal salts; and optionally, one or more pitch control additives. Methods and kits for the formation of said compositions, are also part of the invention, as is the use of said compositions, methods and kits.

The present invention relates to a method of generating chlorine dioxide from chlorite salts in the presence of a manganese ion-containing complex, a method of treating a substrate with a chlorine-containing oxidant in the presence of a manganese ion-containing complex and related aqueous media, kits and compositions.

Compositions and methods that preserve and enhance the brightness of pulp, and also improve the color of pulp or paper, when applied during different stages of a papermaking process, are disclosed. The compositions and methods maintain or enhance brightness, prevent yellowing, and enhance the performance of paper products. The compositions can include a mixture of reducing agents and can also include optical brighteners, chelants, polycarboxylates, or other additives. The mixture of reducing agents can include a borohydride, such as sodium borohydride, and any other reducing agent, such as a sulfite or bisulfite.