Removal of Some Carboxylic Acids from Aqueous Solutions by Hydrogels

Abstract

Carboxylic acids are biotechnological substances that are used extensively in many industries, thus production and separation of carboxylic acids from product mixtures are important scientific and economic problems. The aim of this work was to investigate the removal of acetic, citric, lactic, and tartaric acids from aqueous solutions. With this aim, first the effects of time, temperature, and mixing on separation of the carboxylic acids from aqueous solutions were investigated by experimental work. After the experimental conditions were determined, separation was undertaken for different initial acid concentrations at constant hydrogel concentration. The effect of different gel-acid mass ratios on adsorption at constant initial acid concentrations was determined. The removal of acetic acid was 59.74 %, of lactic acid was 55.45 %, of citric acid was 54.22 %, and of tartaric acid was 56.85 % with a 1.5 hydrogel/acid mass ratio at the lowest concentration of each acid. Results obtained from the experimental work have been used with the Freundlich isotherm.