Fabrication of hydrochar functionalized Fe–Mn binary oxide nanocomposites: characterization and 17β-estradiol removal

Abstract

In this work, Fe–Mn binary oxide modified hydrochar (hydrochar-FMBO) was successfully prepared by deposition of Fe–Mn binary oxide (FMBO) nanoparticles on pristine hydrochar. The as-prepared sample was characterized for its physicochemical properties and employed as an adsorbent for 17β-estradiol (E2) removal from water. The characterization results indicated that nano-sized FMBO particles deposited on the hydrochar matrix. For bath experiments, hydrochar-FMBO showed an excellent E2 adsorption capacity (49.77 mg g⁻¹), which was much higher than the known reported-adsorbents. The adsorption kinetic studies demonstrated that the adsorption of E2 on hydrochar-FMBO was well fitted by the pseudo-second-order kinetic model. Besides, adsorption of E2 on hydrochar-FMBO was a rather complex process involving intraparticle diffusion. In addition, the exhausted hydrochar-FMBO could be regenerated and restored to 83% of its initial capacity in the fifth cycle. Relative mechanistic analyses for the adsorption processes were also provided in this article. These results demonstrated that the modified hydrochar could be efficiently utilized as a high-performance sustainable material for organic contaminants removal.