In-situ immobilization of MIL-100(Fe) on the microchannels in wood aerogel: Efficient persulfate activation toward antibiotic removal

Abstract

Metal-organic frameworks (MOFs) are potential catalysts for persulfate exciting in antibiotic wastewater treatment while are limited in large-scale application given their powder state. Herein, benefiting from the compatibility and functionalization of natural wood supports, MIL-100(Fe) decorated wood aerogel composites (MIL-100(Fe)/WA) were constructed by chemical treatment and in-situ solvothermal synthesis. Na2SO3/NaOH-H2O2 chemical treatment could effectively achieve the partial removal of lignification and hemicellulose in wood, resulting in improved porous characteristics. The corresponding porosity and surface area of WA increased by more than 40% compared with the original wood. Accordingly, after immobilizing MIL-100(Fe) on the microchannels in WA, MIL-100(Fe)/WA-PDS system could efficiently degrade tetracycline (TC), with a satisfied mineralization rate of 64.01% owing to the open porous structure of WA with high accessibility, and its kinetic constant (0.0520 L⋅mg−1⋅min−1) was 6.19 times that of MIL-100(Fe)/wood (0.0084). Quenching results and EPR analysis made clear that TC degradation mainly contributed to the produced O2−, 1O2 and surface-bound radicals (SO4−, OH). LC-MS further uncovered the possible degradative pathways for TC. Moreover, it was found that MIL-100(Fe)/WA could behave well at pH of 2–10 and towards multiple antibiotics. This work may provide a facial way to apply MOFs-based/wood composites in water treatment.