Fullers earth with carbon

The Langmuir equation has been used to describe adsorption of p carotene from solution onto activated bleaching clays (8) and free fatty acid from isooctane solution by acid-washed rice hull ash (9). Likewise, isotherm analysis of the commercial bleaching of rubber and melon seed oil by Fullers earth, activated carbon, and Fullers earth/activated carbon mixture (10) followed Langmuir behavior at 55°C and 80°C, suggesting the possibility of monolayer adsorption with little competition. This behavior was not observed at 30°C where the isotherm no longer applies, because of desorption. The amount of adsorbent was kept constant while varying... 

Vitamin G (Riboflavin) Booher84 employed adsorbents to prepare a vitamin G concentrate from whey. In one procedure, the vitamin in the whey is adsorbed on fullers earth at low temperature and then eluted with hot water. The vitamin in the eluate from the fullers earth is further concentrated by adsorption on activated carbon from which it is subsequently desorbed with an ethanol-benzene mixture, the latter being separated from the vitamin concentrate by evaporation. 

Among the thermal processes, chemical incineration and molten metal reduction can efficiently destroy soman (see Section 39.2). It may be decomposed by oxidizing with A,A -dihalo-2-imidazolidinone in an aqueous emulsion containing tetrachloroethylene (Worley 1989). Hydrolysis with dilute alkalies should form products of low toxicity. Adsorbents such as Fuller s earth, activated carbon, alumina, or silica gel have been reported to remove soman from cleaning organic solvents (Fowler and Mcllvaine 1989). 

Indicated are points obtained in a 1000-atm. experiment with fuller s earth, without activator, as the catalyst, with decalin at 250 atm. one point was obtained with an active carbon-Cr-V catalyst. 

Cottonseed oil is refined by treatment with diluted alkali to neutralize acids, decolorized with fuller s earth or activated carbon, deodorized with steam under reduced pressure, and chilled to separate glycerides and resinous substances of higher melting point. 

Although other adsorbents such as activated carbon, bauxite, and Fuller s earth have been used to desulfurize naphtha, their adsorptiveness is generally thought to be inferior to silica gel with respect to their use for analytical purposes. Recent investigations have revealed that H-41 alumina (available from Aluminum Company of America, Chemicals Division) Ls superior to silica gel for concentrating the sulfur compounds in a Wasson distillate 82% of the total sulfur was concentrated into 1.8% of the naphtha (174). 

Activated clays and fuller s earth are used extensively for decolorizing fats and oils—animal, vegetable, and mineral. In a number of applications, they are used alone but for some fats and oils an admixture with activated carbon is required in order to attain a desired decolorization. Moreover, carbon will remove off-odors and tastes, whereas clays frequently impart a so-called earthy flavor and odor. Consequently, even when not needed for removal of color carbon is often admixed with clay to ensure freedom from any earthy flavor. 

Early studies for the purification of the antipernicious anemia factor used either minced liver preparations or proteolyzed liver extracts in which the concentration of the factor was of the order of one part per million. Adsorption chromatography, partition chromatography, and extraction were the methods of choice for purification. In the initial fractionation steps, the factor was adsorbed on either activated carbon or fuller s earth, and eluted with either aqueous ethanol, phenol, or p3U-idine. Intermediate purification steps were accomplished by partition chromatography adsorption chromatography on either silica or alumina was also effective. At various stages of these column procedures, the activity could be removed from aqueous solution by butanol extraction or with phenol or cresol in combination with solvents such as butanol or toluene. Final purification was usually accomplished by crystallization from aqueous acetone solution. 

The crude hyaluronidase has been purified further by adsorption on alumina C7 (110), on carbon (115), or on Fuller s earth (61) by fractionation with lead acetate (139) or with ethanol (33,37,38,186), or by flocculation with antiserum (17). Madinaveitia (111) has purified the crude ammonium sulfate fraction seven-fold by a lead acetate fractionation. However, this method is not suitable for work on a lai e scale. Tint and Bogash (186) applied a single ethanol fractionation and another ammonium sulfate precipitation and achieved a 20-fold increase in activity with an over-all yield of 30%. Freeman et al. (37-39) increased the activity of the crude enzyme 100-fold by employing a second ammonium sulfate precipitation and two or three ethanol fractionations. The yield was 15% of the crude enzyme. A further ammonium sulfate fractionation doubled the activity. 

The chief adsorptive medium used is granular or powdered carbon that has been activated by steam or chemical treatment to create a porous structure with very high surface area per unit weight of carbon. Fuller s earth, a naturally active clay, is also used as an adsorbent. 

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