Peroxide, hydrogen discharge

Other Polymerization Methods. Experimental allemalives include the use of peroxides, hydrogen fluoride, a sulfonic acid ion-exchange resin, and corona discharge. 

From the defence glands of bombardier beetles a mixture of hydroquinones and hydrogen peroxide is discharged into an extracellular reservoir. There it is piled up and, if the animal is irritated, is released in the so-called reaction chamber, containing catalase and peroxidase. A sudden reaction takes place, the mixture heats up to 100 °C and is ejected by the evolved oxygen gas with a blow. The secretion is very corrosive. It terrifies and injures the aggressor. 

The purple colour of this ion alone is a sufficient test for its presence addition of sulphuric acid and hydrogen peroxide discharges ihe colour. 

Comparison to the Raschig Process. The economics of this peroxide process in comparison to the Raschig or hypochlorite—ketazine processes depend on the relative costs of chlorine, caustic, and hydrogen peroxide. An inexpensive source of peroxide would make this process attractive. Its energy consumption could be somewhat less, because the ketazine in the peroxide process is recovered by decantation rather than by distillation as in the hypcochlorite process. A big advantage of the peroxide process is the elimination of sodium chloride as a by-product this is important where salt discharge is an environmental concern. In addition to Elf Atochem, Mitsubishi Gas (Japan) uses a peroxide process. 

Other Polymerization Methods. Although none has achieved commercial success, there are a number of experimental alternatives to clay-catalyzed or thermal oligomeriza tion of dimer acids. These iaclude the use of peroxides (69), hydrogen fluoride (70), a sulfonic acid ion-exchange resia (71), and corona discharge (72) (see Initiators). 

Disinfection. Chlorine, as gaseous chlorine or as the hypochlorite ion, is widely used as a disinfectant. However, its use in some cases can lead to the formation of toxic organic chlorides and the discharge of excess chlorine can be harmful. Hydrogen peroxide and ozone are alternative disinfectants that lead to products that have a lower toxic potential. Treatment is enhanced by ultraviolet light. Indeed, disinfection can be achieved by ultraviolet light on its own. 

Strong evidence in favor of mechanism B was obtained when it was discovered that singlet oxygen produced chemically by the reaction of hydrogen peroxide and sodium hydrochlorite or from gaseous oxygen excited by an electrodeless discharge yields the same products as the direct photolysis/85-8 ... 

Moore [355] used the solvent extraction procedure of Danielson et al. [119] to determine iron in frozen seawater. To a 200 ml aliquot of sample was added lml of a solution containing sodium diethyldithiocarbamate (1% w/v) and ammonium pyrrolidine dithiocarbamate (1 % w/v) at pH to 4. The solution was extracted three times with 5 ml volumes of 1,1,2 trichloro-1,2,2 trifluoroethane, and the organic phase evaporated to dryness in a silica vial and treated with 0.1 ml Ultrex hydrogen peroxide (30%) to initiate the decomposition of organic matter present. After an hour or more, 0.5 ml 0.1 M hydrochloric acid was added and the solution irradiated with a 1000 W Hanovia medium pressure mercury vapour discharge tube at a distance of 4 cm for 18 minutes. The iron in the concentrate was then compared with standards in 0.1 M hydrochloric acid using a Perkin-Elmer Model 403 Spectrophotometer fitted with a Perkin-Elmer graphite furnace (HGA 2200). 

Joshi, AA Locke, BR Arce, P Finney, WC. Formation of hydroxyl radicals, hydrogen peroxide and aqueous electrons by pulsed streamer corona discharge in aqueous solution. Journal of Hazardous Materials, 1995 41,3-30. 

Lukes, P Appleton, AT Locke, BR. Hydrogen peroxide and ozone formation in hybrid gas-liquid electrical discharge reactors. IEEE Trans. Industrial. Applications, 2004 40 (1), 60-67. 

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