Adsorption of tartaric acid and malic by active carbons

Adsorption of tartaric acid and malic acid by active carbons bas been tested with six samples of carbons. At acid pH ; the adsorbed amounts of tartaric acid and of malic acid are practically the same. For a solution concentration of 20 g/l, adsorbed amounts from 0.008 to 0.29 gramme for one gramme of carbon have been found, variation which may be due to various states of carbon surface oxidation. Increasing the pH of the solutions shows a dramatic decrease of adsorbed amounts, this decrease being more rapid for tartaric acid than for malic acid. At neutral pH, the adsoiption becomes negligible. With acidic solutions containing the two acids altogether, acid malic is more adsorbed than tartaric acid.