Degradation of sulfamerazine using ultrasonic horn and pilot scale US reactor in combination with different oxidation approaches

Abstract

The present study aimed at utilizing ultrasonic horn (USH) and ultrasonic reactor (USR) having provision for dual frequency operation for the successful and cost-effective degradation of sulfamerazine (SMZ). USH and USR were combined with UV, persulfate (PS), peroxymonosulfate (PMS), Fenton (Fe2+/H2O2) and Fenton like (Fe3+/H2O2) process in detailed investigation to establish the optimal loading for obtaining the improved degradation of SMZ quantified in terms of the synergistic index values. A mathematical model was also developed to explain the complex SMZ degradation kinetics for all the AOPs. Significantly higher SMZ degradation (>99 %) was achieved for various combined approaches as USH/PS, USH/PMS, USH/Fe2+/H2O2, USH/Fe3+/H2O2, USH/PS/UV, USH/PMS/UV, USH/Fe2+/H2O2/UV, and USH/Fe3+/H2O2/UV, demonstrating the significant role of SO4¯ and OH radicals in intensifying the oxidation of the SMZ molecules. The pilot scale study with USR also demonstrated effective SMZ degradation using combined AOPs with maximum removal as 94.14 % for USR (22 + 44 kHz)/Fe3+/H2O2/UV. The dual frequency mode of operation was observed to be more efficient than the single frequencies. The cost estimation study based on of cavitational yield revealed that the most cost-effective system was the USR (22 + 44 kHz)/Fe3+/H2O2/UV with a degradation cost of 0.57 ₹/L (0.0069 $/L).