Role of Silica on Clay-Catalyzed Ozonation for Total Mineralization of Bisphenol-A.

Catalytic ozonation for the total mineralization of bisphenol-A (BPA) from aqueous solution was investigated in the presence of various silica-based catalysts such as mesoporous silica, acid-activated bentonite (HMt) and montmorillonite-rich materials (Mt) ion-exchanged with Na and Fe cations (NaMt and Fe(II)Mt). The effects of the catalyst surface were studied by correlating the hydrophilic character and catalyst dispersion in the aqueous media to the silica content and BPA conversion. To the best of our knowledge, this approach has barely been tackled so far.

Silica-catalyzed ozonation of 17α -ethinyl-estradiol in aqueous media-to better understand the role of silica in soils.

A promising route for thorough removal of 17α-ethinyl estradiol (EE2) from aqueous media was achieved through ozonation using mesoporous silicas such SBA-15, SBA-16, MCM-41 and MCM-48 as catalysts. Comparison with aluminosilicates along with Zeta potential and particle size measurements allowed demonstrating that EE2 interaction with silanols and hydrophobic -Si-O-Si- groups are essential requirements for the catalytic activity. Acid-base interactions, if any, should have minor contribution.

Clay-catalyzed ozonation of endocrine-disrupting compounds in solvent-free media - to better understand soil catalytic capacity.

An original approach never tackled so far allowed correlating the basicity and hydrophilic character of clay catalysts to surface interaction with 17α-Ethinylestradiol (EE2) during ozonation in water. The clay catalysts were found to behave specifically according to their silica/alumina ratio like soils in natural oxidative processes. Acid-activated bentonites (HMt) and ion-exchanged montmorillonite (NaMt and Fe(ii)Mt) showed catalytic activity in the ozonation of 17α-ethinylestradiol (EE2) in aqueous media.