Flexible preparation of nanoporous SiO₂ aerogel as novel adsorbent for efficient adsorption of Zearalenone

Zearalenone (ZEN) is a form of mycotoxin in the animal feed that is a carcinogen causing pathological changes after entering animal and human body. In the paper, SiO₂ aerogels were prepared using sol-gel method adopting atmospheric pressure drying, vacuum drying and combustion drying. The aerogels were characterized and subjected to assess the sorption potential of ZEN. It was found that the atmospheric pressure drying aerogel (ADSA) had the highest surface area and micropore content, while the vacuum drying aerogel (VDSA) was completely mesoporous with the smallest surface area. The combustion drying aerogel (CDSA) was also dominantly mesoporous with fractional micropores. The ZEN equilibrium adsorption capacity for ADSA was the highest while its adsorption rate was the lowest. The adsorption rate of VDSA was the highest, while its equilibrium adsorption capacity was significantly lower than ADSA. The adsorption capacities of VDSA and CDSA were of comparable magnitude owing to the similarity in pore structure. The adsorption isotherms and kinetics were modeled with semiempirical theoretical models. The ZEN adsorption process of all the aerogels was governed by both physisorption and chemisorption. Experimental result suggested a flexible option of SiO₂ aerogels as promising low cost absorbent for ZEN removal.