Fenton

Fenton s reagent. To a solution of tartaric acid or a tartrate add 1 drop of freshly prepared ferrous sulphate solution, i drop of hydrogen peroxide solution and then excess of NaOH solution an intense violet coloration is produced, due to the ferric salt of dihydroxyfumaric acid, HOOC C(OH) C(OH)COOH. 

No coloration with Fenton s reagent cf. tartaric acid). 

Water loss in operating an HDR faciUty may result from either increased storage within the body of the reservoir or diffusion into the rock body beyond the periphery of the reservoir (38). When a reservoir is created, the joints which are opened immediately fill with water. Micropores or microcracks may fill much more slowly, however. Figure 11 shows water consumption during an extended pressurization experiment at the HDR faciUty operated by the Los Alamos National Laboratory at Fenton Hill, New Mexico. As the microcracks within the reservoir become saturated, the water consumption at a set pressure declines. It does not go to zero because diffusion at the reservoir boundary can never be completely elirninated. Of course, if a reservoir joint should intersect a natural open fault, water losses may be high under any conditions. 

Fig. 12. HDR reservoir flow test at Fenton Hill, New Mexico (1992) (39). (a) Injection pressure profile ( ) and a sismic limit (-------) (b) injection ( )...

N. E. V. Rodrigues, B. A. Robinson, and E. Counce, "Tracer Experiment Results During the Long-Term Flow Test of the Fenton Hill Reservoir", Proceedings of the Eighteenth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, Calif., 1994, in press. 

D. W. Brown and R. DuTeau, "Progress Report on the Long-Term Flow Testing of the HDR Reservoir at Fenton Hill, New Mexico", in Ref. 37. 

Hydrogen peroxide may react directiy or after it has first ionized or dissociated into free radicals. Often, the reaction mechanism is extremely complex and may involve catalysis or be dependent on the environment. Enhancement of the relatively mild oxidizing action of hydrogen peroxide is accompHshed in the presence of certain metal catalysts (4). The redox system Fe(II)—Fe(III) is the most widely used catalyst, which, in combination with hydrogen peroxide, is known as Fenton s reagent (5). 

Fenton chemistry is dependent on the formation of free radicals. 

Oxidation. Coumarin is not readily oxidized by chromic acid but, by action of the Fenton s reagent, it is converted into 7-hydroxycoumarin (umbeUiferone) [93-35-6] (28). 

Oxidation. Oxidation is one of the main chemical methods to treat and decompose dyes in wastewater. The oxidation agents used ate chlorine, bleach, ozone, hydrogen peroxide, Fenton s reagent, and potassium permanganate. 

One method of generating hydroxyl radicals is by a dding a soluble iron salt to an acid solution of hydrogen peroxide (Fenton s reagent) (176—180), ie ... 

Several papers and patents describe treating dye-containing wastewaters with Fenton s reagent with and without other methods such as coagulation, incineration, biodegradation, etc (130,181—187). 

The uv—hydrogen peroxide system has advantages over the iron—hydrogen peroxide (Fenton s reagent) procedures, eg, the reaction is not limited to an acid pH range and the iron catalyst and resulting sludges are eliminated. However, the system to date is not effective for dye wastewaters because of absorption of uv by colored effluent. 

RUFF - FENTON Degradation Oxidative degradation of aldoses via a-hydroxy acids to lower chain aldoses. 

Fenton, W.A., et al. Residues in chaperonin GroEL required for polypeptide binding and release. 

Later, Du Pont in America developed its own ionically conducting membrane, mainly for large-scale electrolysis of sodium chloride to manufacture chlorine, Nafion , (the US Navy also used it on board submarines to generate oxygen by electrolysis of water), while Dow Chemical, also in America, developed its own even more efficient version in the 1980s, while another version will be described below in connection with fuel cells. Meanwhile, Fenton et al. (1973) discovered the first of a... 

---