Evaluation of the potential of coal fly ash produced by gasification as hexavalent chromium adsorbent.

The aim of this work was to characterize the coal fly ash from gasification process (G-CFA) and to analyze its potential as hexavalent chromium Cr (VI) adsorbent. The G-CFA was characterized in terms of physical, chemical, mineralogical, and morphological analyses. Bach adsorption studies were carried out in order to evaluate the influence of pH on the adsorption capacity and removal efficiency of Cr (VI). The G-CFA characterization demonstrated that the material possessed potential to be applied as an effective low-cost adsorbent, once it presents 18.82 m2 g-1, 0.036 cm3 g-1, and 7.56 nm of surface area, pore volume, and average pore diameter, respectively. The results also showed well-defined mineralogical phases and high content of siliceous material. The adsorption experiments demonstrated that the material has potential to be used as a chromium adsorbent with high removal efficiencies.