Effect of humic acid on adsorption of methylparaben from aqueous solutions onto commercially available granular activated carbons

Abstract

Adsorption of methylparaben (MP) on Calgon carbon (F400) and Norit-type Granular Activated Carbons (GACs) from aqueous solutions was examined. The influence of Humic Acid (HA) on the adsorption of MP under different pH conditions was evaluated. The adsorption isotherm results are well described by the Freundlich model. The MP adsorption capacity on F400 and Norit GACs was found 150 mg/g. In the presence of Total Organic Carbon (TOC) with 2.357 mg/L HA, the maximum MP adsorption capacity on F400 G AC at pH 7 increased 2.2 folds. The Norit-type G AC had a comparatively higher uptake capacity for MP than F400 GAC. The key mechanism for MP adsorption onto the F400 G AC was through the hydrogen interaction between the -OH functional groups of the MP molecules. The MP adsorption capacity on Norit GAC increased from 5 to 100 mg/g at pH 7.