Fe₃C/Fe/C Magnetic Hierarchical Porous Carbon with Micromesopores for Highly Efficient Chloramphenicol Adsorption: Magnetization, Graphitization, and Adsorption Properties Investigation

Here, the magnetic hierarchical porous carbon (MHPC) with micromesopores was first prepared using ethylenediaminetetraacetic acid tripotassium (EDTA-3K) and iron nitrate by simultaneous magnetization/activation method. The optimal product was MHPC-20 with a high graphitization, which possessed a large <i>S</i>_BET (1688 m² g^–1) and saturation magnetization (3.679 emu g^–1). As expected, MHPC-20 had a very high maximum adsorption capacity (534.2 mg g^–1) toward chloramphenicol (CAP) from water solution at 298 K with a positive correlation between <i>S</i>_BET and adsorption amount. Additionally, MHPC-20 had a fast adsorption kinetic, only 250 min, and isothermal and kinetics data were well fitted by Langmuir and pseudo-second-order kinetic models, respectively. Moreover, the effect of ion strength, solution pH, and humic acid on CAP adsorption onto MHPC-20 were investigated, indicating a better stability. Besides, MHPC-20 showed good reusability and excellent magnetic separation performance, which implied MHPC-20 as a candidate could be applied in various complex wastewater environments

From Lignin to Three-Dimensional Interconnected Hierarchically Porous Carbon with High Surface Area for Fast and Superhigh-Efficiency Adsorption of Sulfamethazine

A novel three-dimensional lignin-based interconnected hierarchical porous carbon (3DLHPC) with very high specific surface areas (2784 m² g^–1) and large pore volumes (1.382 cm³ g^–1) was prepared using sodium lignin sulfonate as carbon precursor, via confinement carbonization, etching silica-template, and <i>in situ</i> alkali activation, for fast and super highly efficient removal of sulfamethazine (SMZ) antibiotics from water. By batch adsorption experiments test, 3DLHPC showed a strong adsorption affinity for SMZ with the maximum monolayer adsorption capacity of 869.6 mg g^–1 at 308 K. Owing to this well-defined 3D interconnected hierarchical porous structure, the adsorption equilibrium could be reached within 30 min at 298 K. The adsorption mechanism might be involved in van der Waals force, π–π EDA interaction, electronic interaction, and hydrophobic interaction, as well as hydrogen bonding interaction. Meanwhile, it was demonstrated that 3DLHPC exhibited excellent regeneration ability, showing the potential possibility for antibiotic wastewater treatments