Supporting Oxides on Charcoal via Wet Impregnation for Nitrate Removal from Water

Abstract

This work investigates the synthesis of M-oxides (M = aluminum, iron, magnesium, zinc) supported on charcoal by wet impregnation and using these materials in removing nitrate from water. On the one hand, it studies the incorporation of the solid and the modification that the carbonaceous support undergoes, and on the other hand, it investigates the performance of the material produced in the synthesis compared to charcoal acting as a control group. In the first part, the incorporation of the solid material was characterized structurally (SEM, Hg porosimetry) and compositionally (XRD, elemental analysis), and the modification of the carbonaceous support was characterized by the yield and the amount of solid incorporated in the synthesis product (TGA). The results show that the synthesis by wet impregnation produces a composite material formed by a porous matrix of carbon-containing solid in an amount, with a distribution and precursor-dependent crystallinity. The synthesis also results in the loss of a significant amount of carbonaceous support, which varies from precursor to precursor. The results also show that only the material with zinc oxide outperforms the material with no added solid in removing nitrate from water. Finally, this work´s results show that wet impregnation allows obtaining materials that improve the ability to remove nitrate from water. However, they show that the carbonaceous support undergoes a significant change whose influence on nitrate removal remains unknown.