Applications of Novel Composite Support Materials Capable Of Incorporating In-Situ Dual Effect for Degradation of Isoproturon

Abstract

An unprecedented concept of integrated process by coupling photocatalysis and photo-Fenton especially in fixed mode has been presented in the current study for the removal of contaminants like isoproturon from aqueous solution in reduced treatment time. For fixed-bed studies spherical beads were prepared by combining definite proportions of clay, foundry sand (FS) which was utilized as an iron source and fly ash (FA) for TiO2 immobilization. The parametric optimization was carried out using Box–Behnken design model (BBD) and response surface methodology. The process of degradation followed the first order kinetics with optimized condition for the integrated degradation of isoproturon with 0.444 ml dosage of H2O2, 42 spherical beads and 190ml of solution for duration of 176 min at pH 3.7. Approximately 80.96% reduction in the concentration of compound was observed after inducing the optimized conditions. The experiment was performed both in the presence of artificial UV light and natural sunlight to check the comparative efficiency of both the processes. The integrated treatment was also carried out in solar batch reactor under optimized conditions to expand its application to the industries for treating bio-recalcitrant compounds. The mineralization of isoproturon was validated through generation of nitrite, nitrate and nitrogen along with a definite reduction in COD. The recyclability of catalyst was confirmed by recycling the spherical beads characterized by the SEM/EDAX. The presence of iron along with TiO2 on the surface of beads was confirmed through SEM-EDS, UV, DRS and FTIR. A tentative pathway for the degradation of isoproturon was also proposed based on the identification of intermediates through GC–MS analysis.