Recyclable porous materials for the uptake of bisphenol A

Abstract

The presence of pollutants in the environment, food, drinking water and other compounds in direct or indirect contact with humans is a major environmental issue. In this regard, a privileged place reverts to the capture or decomposition of pollutants without producing traces of residual toxins. An interesting approach for depollution is the use of natural, non-toxic, recyclable materials as adsorbents and catalysts. The aim of this work was to study the ozonation of bisphenol-A in water in the presence of Bentonite and its acid-activated counterparts AAB1, AAB4, AAB8, AAB15 and AAB24 obtained after 1, 4, 15 and 24 h of acid treatment. For comparison, one also used two deriving montmorillonite-rich materials ion-exchanged with Na+ and Fe2+ cation, namely, NaMT, Fe(II)MT. The kinetic and thermodynamic parameters of the process were assessed through UV-Vis spectrophotometric measurements, and were discussed in correlation with thermo-programmed desorption technique (TPD) data. Calculations of the retention capacities of CO2 and H2O (CRC and WRC) revealed high basic character (high CRC) for NaMT but lower hydrophilic character (low WRC) as compared to Fe(II)MT. This explains the higher catalytic activity of Fe(II)Mt by enhanced interaction with basic bisphenol (pka = 9.2 at 25oC), which favors adsorption, and higher dispersion in water, which offer higher contact surface as compared to NaMt. This provides valuable date for designing effective oxidative water treatments using clay materials and other natural’s counterpart.