Sorption of n-valeric acid

Experimental conditions 20 x 1.4 cm ED glass column, 5g/L n-valeric acid solution, 1 ml/min. Reprinted from [34] with permission of Elsevier. 

Under dynamic conditions the capacity of microporous Styrosorbs at 5% breakthrough amounts to 0.4—0.5g/g, which relates to 30—40 bed volumes of treated solution with a concentration of 5 g/L. In contrast, dynamic breakthrough volumes for Amberlite XAD-4 and XAD-1180 resins turned out to be lower by a factor of 2. 

Large-scale production of optically active a-amino acids has usually been performed by microbiological synthesis or through hydrolysis of waste proteins. In both cases, a serious problem is the isolation of pure crystalline amino acids because numerous by-products are present in solutions. In 

Under dynamic conditions the breakthrough of some colored bodies takes place rather soon, possibly that of the most hydrophiUc or most voluminous fractions of melanoidins. However, even the last portion of 150 mL cultural liquid percolated through 3g of the biporous sorbent shows a 70% degree of clarification here the dynamic sorption capacity achieves a very high value of 670 mg/g. Of several regeneration tests, the best results were achieved when using mixtures of sodium hydroxide solution with isopropanol 3—5 bed volumes were found to be sufficient to regenerate the sorbent comprehensively. Three consequent cycles of sorption-desorption do not deteriorate the performance of the hypercrosslinked Styrosorb IBP. 

Complex colored bodies present in L-tryptophan fermentation solutions readily adsorb onto industrial biporous MN-200. One bed volume of the latter clarifies approximately 30 volumes of the cultural liquid or 17—18 vol. of its concentrate. The sorption capacity of other industrial 

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