The degradation and mineralization of hydrochlorothiazide (HCTZ) using catalytic ozonation process (COP) with Al2O3/granular activated carbon composite

In this study, Al2O3/GAC (granular activated carbon) composite was prepared and used in the catalytic ozone process (COP) to degrade hydrochlorothiazide (HCTZ). Regarding SEM, EDAX, XRF, FTIR, and BET analysis, the coated alumina on the GAC surface was identified and confirmed. The Al2O3/GAC composite is completely resistant to ozone, and its efficiency in the degradation of HCTZ is almost constant after 20 uses in the catalytic ozonation process COP (93 ± 1%). The Al2O3/GAC composite has increased the efficiency of the ozonation process by 48% under optimal operating conditions and a reaction time of 5 min. Also, Al2O3/GAC under optimal operating conditions and reaction time of 15 min has increased the efficiency of the ozonation process in removing HCTZ, degradation of HCTZ, and removing COD and TOC by 23%, 19%, 24%, and 15%. The kinetics of HCTZ degradation in COP and the single ozonation process (SOP) were consistent with pseudo-first-order kinetics (R2 > 0.99). The rate of HCTZ degradation reactions in COP with Al2O3/GAC is about 2.78 times faster than the rate of SOP. The formation of free radicals in ozone catalysts with alumina is confirmed in addition to surface radicals. For the first time in this study, the degradation pathways of HCTZ in COP were identified. The Al2O3/GAC composite can be used as an inexpensive, recyclable, and efficient catalyst in the chemical degradation of various drug compounds in COP.