| 摘要 |
In a process of treating liquids with activated carbon for purification decolorization, deodorization, &c., at least two different types of activated carbon are successively used, the type first used having a relatively steep absorption isotherm whilst the type or types subsequently used has or have a flatter isotherm or progressively flatter isotherms. The carbons may be used in granular form, for example as filters in layers, the first filter adsorbing impurities of higher molecular weight or present at greater concentrations in the liquid, and the second filter adsorbing impurities of lower molecular weight or as lower concentrations. The carbons may also be used in powdered form either deposited on filtering material through which the liquid to be treated is passed, or mixed with the liquid. In the latter case the liquid may be filtered after having been in contact with a carbon of the first type for sufficient time, and before being mixed with carbon of the second type, or the different types of carbon may be added to the liquid without intermediate filtration, sufficient time being allowed for a carbon of one type to react fully with the liquid before carbon of another type is added. The liquid may be treated partly with granular activated carbon and partly with powdered activated carbon. The carbons may be added to the liquid wholly or partly in counter-current.ALSO:In a process of treating liquids with activated carbon at least two different types of activated carbon are used in succession the type first used having a relatively steep adsorption isotherm whilst the type or types subsequently used has or have a flatter isotherm or progressively flatter isotherms. Examples are given of the treatment of a sugar solution and a glucose juice. The carbons may be used in granular form for example as filters in layers, or may be used in powdered form, either deposited on filtering material through which the liquid to be treated is passed, or mixed with the liquid. In the latter case the liquid may be filtered after having been in contact with a carbon of the first type for sufficient time, and before being mixed with carbon of the second type, or the different types of carbon may be added to the liquid without intermediate filtration, sufficient time being allowed for a carbon of one type to react fully with the liquid before carbon of another type is added. The liquid may also be treated partly with granular activated carbon and partly with powdered activated carbon. The carbons may be added to the liquid wholly or partly in countercurrent.
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