Abstract

An electro-catalytic ozonation process with ZnO nano-granules as a catalyst (CFR-EC/O3-UV@ZnO process) was developed to treat raw landfill leachate. LC-MS analysis was applied to determine organic compounds. After CFR-EC/O3-UV@ZnO process, COD, TOC, BOD5, NH4+-N, P-PO4−3, color, and turbidity were reduced to 90.9, 89.4, 89.1, 89.5, 87.7, 99.1, and 99.7, respectively under the optimum conditions of 10 g.hr−1 O3 dosage, pH 11.0, and 0.006 L.min−1 flowrate. At the same conditions removal efficiencies of heavy metals (HMs): Cr6+, Pb2+, As3+, Mg2+, B3+, Mn3+, Ni2+, Ba2+, Hg2+, Co2+, Fe2+, and Li+ were obtained 90, 84.7, 90, 99, 83.7, 95, 20, 75, 91, 90, 78 and 60, respectively. In spite of high COD and BOD5 removal efficiencies, the process could not remove two organic substances including diphenylamine and 2,2,4-trimethyl-1,3-pentanediol. A high R2 value of 0.99 demonstrated the accuracy of the selected model. Economic evaluation depicted that the current process cost 0.95 .m−3. Finally, this process is suggested for the treatment of landfill leachate with relatively high efficiency. © 2024 Elsevier B.V.