Efficient Removal of Cr(VI) from Water by Carbon-Based Composites Derived from Oil-Based Drill Cuttings

Oil-based drill cuttings (OBDCs) have received extensive attention for their environmental impacts and safe disposal. In this study, a high-performance sorbent material was prepared via the chelation and carbonization reaction for the high-value resource utilization of OBDCs. The coordination interaction between the organic acids and metal ions acted as a carbon source. Then, the metal elements were encapsulated into the formed carbon matrix. The results showed that the obtained composites exhibited abundant honeycomb-like pore structures. The addition of citric acid facilitated the formation of graphitized carbon materials and increased the specific surface area and surface functional groups. Impressively, the composites exhibited excellent adsorption performance for Cr(VI), with a maximum adsorption capacity of 56.84 mg/g. The adsorption process followed the pseudo-second-order kinetic model, and was mainly dominated by chemical adsorption. The excellent adsorption properties were attributed to the unique properties of the prepared carbon-based composites, including their large surface area, numerous pore structures, and abundant surface functional groups. This study provides new ideas related to the resource utilization of hazardous organic waste.