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Chemical pulping involves dissolving lignin in order to extract the cellulose from the wood fiber. The different processes of chemical pulping include the Kraft process, which uses caustic soda and sodium sulfide and is the most common; alternatively, the use of sulfurous acid is known as the sulfite process, the neutral sulfite semichemical is treated as a third process separate from sulfite ...
The pulp produced up to this point in the process can be bleached to produce a white paper product. The chemicals used to bleach pulp have been a source of environmental concern, and recently the pulp industry has been using alternatives to chlorine, such as chlorine dioxide, oxygen, ozone and hydrogen peroxide.
It is used in topical medications for acne [19] and to bleach flour. [22] Ozone (O 3). While not properly a peroxide, its mechanism of action is similar. It is used in the manufacture of paper products, especially newsprint and white kraft paper. [23] Potassium persulfate (K 2 S 2 O 8) and other persulfate salts. It, alongside ammonium and ...
The kraft process involves treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na 2 S), known as white liquor, that breaks the bonds that link lignin, hemicellulose, and cellulose. The technology entails several steps, both mechanical and chemical. It is the dominant method for producing paper.
A new study from Belgian researchers found that paper straws had higher concentrations of long-lasting, water resistant "forever chemicals" than plastic or steel straws.
Sixty-nine percent of the brands contained PFAS, with paper straws more likely to contain the chemicals. The researchers found 90% of paper straws had PFAS, compared to 80% of bamboo straws, 75% ...
All bleaching agents used to delignify chemical pulp, with the exception of sodium dithionite, break lignin down into smaller, oxygen-containing molecules. These breakdown products are generally soluble in water, especially if the pH is greater than 7 (many of the products are carboxylic acids). These materials must be removed between bleaching ...
Researchers have identified nearly 200 chemicals used to make food packaging that could possibly increase the risk of breast cancer.. Found in plastics and paper, some of the potential mammary ...