Adsorption of 17β-estradiol from aqueous solutions by a novel hierarchically nitrogen-doped porous carbon.

A novel interconnected hierarchically nitrogen-doped porous carbon (IHNPC) derived from metal-organic framework-based composites was obtained via a facile method and applied as a superior material for the capture of 17β-estradiol (E2) from aqueous solution. The adsorption kinetic and isotherm behaviors were well described by the pseudo-second-order and Langmuir models. Various thermodynamic parameters uncovered that E2 adsorption onto IHNPC was spontaneous and exothermic. Moreover, the adsorption rate of E2 by IHNPC didn't decrease with increasing water salinity in the presence of electrolyte ions and humic acids. Naturally occurring aquatic particles can enhance (i.e., Al2O3), decrease (i.e., kaolin and SiO2) or have no obvious effects (i.e., montmorillonite) on the adsorption rate of E2 by IHNPC. The high adsorption capacity and remarkable adsorption selectivity of IHNPC highlighted the application of IHNPC for the capture of E2 and provided understanding of the fate and transport of E2 in natural aquatic environments.