Synthesis of a novel three-dimensional porous carbon material and its highly selective Cr(VI) removal in wastewater

Abstract

Cr(VI) in water severely affects human health. In this study, a kind of novel 3D porous carbon material (3D-PCM) was prepared using glucose and urea via two-stage-hydrothermal and activation method for Cr(VI) removal in wastewater. The SEM demonstrate that 3D-PCM has a developed pore structure, and BET test shows that its specific surface area reaches 1554.77 m2/g. Batch adsorption experiments showed that the best pH is about 2.0 The Cr(VI) adsorption process on 3D-PCM follows pseudo-second-order kinetics and Freundlich model, and the maximum adsorption capacity reaches 837.19–951.65 mg/g (25–45 °C), which is higher than those of similar adsorbents in the world. Through the combination of chemical characterization and adsorption model analysis indicate that the main adsorption mechanisms on 3D-PCM include electrostatic interactions, ion complexation, physical adsorption, reduction and hydrogen bonding. Moreover, the multi-ion competitive simulation and adsorption and regeneration experiments showed that 3D-PCM has excellent selectivity and regenerative performance for Cr(VI) adsorption. Economic analysis shows that the manufacturing cost of 3D-PCM is low. Therefore, 3D-PCM is an effective and reusable material for Cr(VI) removal, and its preparation method is green and sustainable, which is expected to improve the problem of Cr(VI) pollution in water.