Preparation of iron-impregnated tablet ceramic adsorbent for arsenate removal from aqueous solutions

A novel tablet ceramic adsorbent (TCA), developed with a mixture of Akadama mud, wheat starch, and Fe2O3, was used to remove excessive arsenate from its aqueous solution. To improve As (V) removal, iron impregnation was applied to modify the TCA. Detailed characterization has shown that the modified sorbent has a specific surface area of 45.6 m(2)/g, an iron content of 29.1%, and a pH(pzc) of 5.5. The sorbent possesses a rough surface and many macropores and mesopores developed on the surface. Moreover, it was revealed that the exterior roughness not only appeared on the modified TCA surface but also spread into open pores in each grain during the iron impregnation process. The As (V) adsorption capacity of the iron-impregnated TCA (ITCA, 8.49 mg/g) was approximately two times of that of the raw TCA (5.32 mg/g), estimate by the Langmuir-Freundlich (L-F) equation. Both batch and column results indicated that ITCA had the advantages of efficient arsenic removal, wide adaption pH range, sludge free and rapid separation, and it can be used as a promising adsorbent for arsenic removal. (C) 2011 Elsevier B.V. All rights reserved.