Wolters Kluwer - Medknow Wolters Kluwer India Pvt. Ltd. International Journal of Environmental Health Engineering (IJEHE) AWAITED 1 August 2012 08 01 Performance of the catalytic ozonation process with pumice in removal of humic acids from aqueous solutions 1 7 27274 10.4103/2277-9183.99327 EN Ghorban Asgari Department of Environmental Health Engineering, Faculty of Health, Hamadan University of Medical Sciences, Hamadan, Iran Abdolmotaleb Seyd Mohammadi Department of Environmental Health Engineering, Faculty of Health, Hamadan University of Medical Sciences, Hamadan, Iran Afshin Ebrahimi Environment Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Journal Article 2023 02 05 <strong>Aims:</strong> This study was conducted to evaluate the feasibility of applying pumice as a catalyst in the ozonation process for removal of humic acids from aqueous solutions. <strong>Materials and Methods:</strong> The molecular structure and chemical composition of pumice were determined using X-ray fluorescence (XRF) and X-ray diffraction (XRD). The catalytic ozonation experiments were performed in a semi-batch reactor and the mass of ozone produced was measured by means of iodometric titration methods. Concentration changes in humic acid were determined using a spectrophotometer, at an absorption wavelength of 254 nm. To evaluate the performance of catalytic ozonation in humic acid removal, effects of different parameters including pH, contact time, pumice dosage, and t-butyl alcohol (TBA) were examined. <strong>Results:</strong> The catalytic ozonation results showed that the use of pumice as a catalyst increased the decomposition of humic acid eight times, and the removal efficiency increased as the pH changed from 4 to 12 and catalyst dosage changed from 0.25 to 10 g/l. The catalytic ozonation with considerable efficiency (90%) removed humic acid in less time (10 minutes) than the sole ozonation process (SOP). Moreover; the results indicated that the catalytic ozonation process (COP), compared to conventional SOP, was less affected by the radical scavenger. <strong>Conclusions:</strong> Due to the low cost, easy access, and remarkable performance of pumice as a catalyst, it can be used in conventional sole ozonation processes for removing organic pollutants. https://ijehe.mui.ac.ir/article_27274_c712cafa19f7f3dfbd8a72abeac78ec8.pdf