Hydrogen peroxide in bleaching

Amperometric detection of hydrogen peroxide in bleaching and washing processes... 

The influence of the concentration of iron ions on decomposition of hydrogen peroxide in bleaching liquor is shown in Fig. 12-11. The influence of the concentration of complexing agent on decomposition of iron complexing peroxide bleaching liquor and cellulose is shown in Fig. 12-12. The rapid release of large amount... 

Hydrogen peroxide in aqueous solution has many uses, because the products from its reaction are either water or oxygen, which are generally innocuous. The chief use is bleaching of textiles, both natural and synthetic, and of wood pulp for paper. Other uses are the oxidation of dyestuffs, in photography and in the production of... 

Bleaching. The largest single use for hydrogen peroxide in the United States and North America is wood pulp bleaching, but consumption for the manufacture of chemicals, environmental appHcations, and for bleaching cotton (qv), wool (qv), and other textiles (qv) is significant. 

Sodium peroxoborate hexahydrate is an important ingredient of many household detergents, working best at temperatures above 60°C. It is also used in dishwasher detergents, denture cleaners, as well as foot and bath salts. The textile industry generally uses hydrogen peroxide for bleaching, but there are a few areas in which sodium peroxoborate hexahydrate is preferred. 

The perhydroxyl ion, OOH , derived from the dissociation of hydrogen peroxide in alkaline solution, is generally considered the active agent in the bleaching of wood pulp using hydrogen peroxide. This ionization may be expressed by the following reversible reaction ... 

Whiter fabrics are produced if an oxidative bleaching is followed by a reductive one this is often referred to as full bleaching. One such process involves a hydrogen peroxide oxidative bleaching, followed by addition of thiourea to the Hquor to generate thiourea dioxide for a reductive bleach in situ (115). 

Increased usage of recycled fiber in combination with system closure and Hydrogen Peroxide (HP) bleaching at moderate temperatures, has developed microbe cultures that are very effective in decomposing (HP). As this problem often comes slowly when the mills are closing their water loops and reuses their wastewater it is sometimes difficult to say when it needs to be treated. 

Semichemical pulps are typically bleached with hydrogen peroxide in a bleach tower. 

Figure 10.21 Relative stain removal after 60 min bleaching at 60 °C [233] 6.5 x 10 3 mol/l hydrogen peroxide in buffer solution. Relative share (%) of the protolytic forms of hydrogen peroxide in the total amount at 60 °C ( 0-0 negligible in this range)...

It is possible to use an enzyme with hydrogen peroxide in a combined desize-bleach but great care is needed in selection of the enzyme and optimisation of the concentrations [319]. 

Peracetic acid or its anion, produced in situ from A, A, A, A -tetraacetylethylenediamine, in the presence of hydrogen peroxide, in slightly alkaline solution (equation 14), is an effective bleaching agent used in pulp manufacture and laundering. Household washing solution formulations contain perborate and activators that produce peracetic acid of bleaching effect . ... 

The device was a chemical scrubber in which chemicals were added to the water passing counter-current to the air flow to react with the pollutants. Typical oxidizing agents used included hypochlorites, peroxides, and permanganates. Caustic, hydrogen peroxide, and bleach were all used at different times. The OCSD was interested in exploring conversion of the scrubbers to biofilters in order to reduce the operating costs and the costs of chemicals. 

When using peroxidase and DAB, it is sometimes necessary to bleach the brown pigment found in fixed tissue sections, e.g., in formol saline fixed red blood cells. Bleach with 7.5% hydrogen peroxide in distilled water for 5 min. Wash well in tap water. 

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