Search results
Results from the WOW.Com Content Network
The traditional ECF sequence is DEopDEpD [1]: 14 using the common letter symbols for bleaching stages, [2] though many improved sequences are available. [ 1 ] : 15 Totally chlorine free (TCF) is paper that does not use any chlorine compounds for wood pulp bleaching.
Most TCF pulp is produced in Sweden and Finland for sale in Germany, [31] all markets with a high level of environmental awareness. In 1999, TCF pulp represented 25% of the European market. [32] TCF bleaching, by removing chlorine from the process, reduces chlorinated organic compounds to background levels in pulp-mill effluent. [33]
The principal example is tert-butyl hypochlorite, which is a useful chlorinating agent. [3] Most hypochlorite salts are handled as aqueous solutions. Their primary applications are as bleaching, disinfection, and water treatment agents. They are also used in chemistry for chlorination and oxidation reactions.
Percent active chlorine in these materials ranges from 20% for bleaching powder to 70% for HTH. Potassium hypochlorite, KOCl. This was the first chlorine-based bleaching agent, which became available around 1785 under the name Eau de Javel or "Javel water". It is no longer commonly used, having been superseded by the cheaper sodium analog.
Trichloroisocyanuric acid is an organic compound with the formula (CONCl) 3.It is used as an industrial disinfectant, bleaching agent and a reagent in organic synthesis. [1] [2] [3] This white crystalline powder, which has a strong "chlorine odour," is sometimes sold in tablet or granule form for domestic and industrial use.
Dichloroisocyanuric acid is an oxidizer, reacting with water to form chlorine gas. [2]Although the bleaching agent in most chlorine based bleach is sodium hypochlorite, the sodium salt of dichloroisocyanuric acid, sodium dichloroisocyanurate, is the active ingredient in commercial disinfectant bacteriocides, algicides, and cleaning agents [3] such as the pulverized cleanser Comet.
On the one hand, paper and chemical industry-funded studies have generally found that there is no environmental difference between ECF and TCF effluents. [42] On the other hand, an independent peer-reviewed study has found that, comparing conventional, ECF and TCF effluents before and after secondary treatment, "TCF effluents are the least toxic."
Calcium hypochlorite is an inorganic compound with chemical formula Ca(Cl O) 2, also written as Ca(OCl) 2.It is a white solid, although commercial samples appear yellow. It strongly smells of chlorine, owing to its slow decomposition in moist air.