Removal of organic compounds by alginate gel beads with entrapped activated carbon

The adsorption of alginate gel (AG) beads and AG with activated carbon entrapped (AG-AC) beads prepared using different types of metal ions were investigated by measuring the removal of several organic compounds with different charges and size. AG-AC beads prepared in a CaCl2 solution adsorbed strongly positively charged compounds as well as electrically neutral and low molecular weight compounds such as p-chlorophenol. However, a high molecular weight humic acid was not adsorbed by AG-AC. The AG-AC selectively adsorbed p-chlorophenol from a humic acid solution. The adsorption capacity obtained from the adsorption isotherm of AC entrapped in AG was compared with that of AC. The AG-AC beads prepared in a solution of FeCl3 were able to specifically adsorb negatively charged gallic acid. Thus, entrapping AC into AG resulted in the selective adsorption. (c) 2005 Elsevier B.V. All rights reserved.