Hexagonal bipyramidal Fe-MIL confined grown on network magnetic P-doped biochar: Efficient co-adsorption of As(V) and meloxicam

With the increasingly serious water pollution, effectively removing heavy metal ions and drug residues from wastewater has become a key issue in environmental protection. A 3D network Fe-MIL/magnetic P-doped biochar material (Fe-MIL/Fe-PBC) has been constructed through the strategies of simultaneous heteroatom doping and morphology modulation, magnetization modification, charge modulation and confined recombination to achieve the co-adsorption of drug residues and anionic heavy metals within the pH range of 3-12. Therefore, in real water samples (pH 6-9), Fe-MIL/Fe-PBC can achieve good co-adsorption. The Fe-MIL/Fe-PBC showed excellent adsorption ability for As(V) (AsO₄^3-) and meloxicam (MLX) in the single and binary systems (single: q_As=250.00 mg g^-1, q_MLX=352.58 mg g^-1; binary: q_As=303.03 mg g^-1, q_MLX=400.00 mg g^-1). This is mainly due to the inert activation effect as well as the additional active sites brought by P doping and MIL recombination to the BC-based materials, aided by the charge regulation of the magnetic components. The sponge-packed column filled with Fe-MIL/Fe-PBC demonstrates the ability to continuously remove MLX (195 B.V.) and As(V) (85 B.V.) from water. Fe-MIL/Fe-PBC possesses strong water treatment capabilities and high resistance to interference. Furthermore, the removal efficiency of MLX and As for Fe-MIL/Fe-PBC in 7 cycles was both above 80 %, proving that the material has favorable reusability. The outcomes of the experiment and the characterization findings mutually validate one another, offering robust support for the hypothesized adsorption mechanism. In conclusion, the Fe-MIL/Fe-PBC exhibits extensive application potential in the realm of environmental remediation.