Catalytic ozonation of 2, 4-dichlorophenoxyacetic acid wastewater by Fe-La@ZE catalyst

This study developed a salt-tolerant multimetal ozone catalyst Fe-La@Zeolite (Fe-La@ZE) and effectively catalyzed the ozone depletion of high-salinity 2,4-dichlorophenoxyacetic acid wastewater (2,4-D) and an entropy to evaluate the comprehensive gray cluster analysis model was created using catalytic ozonation conditions. Characterization results show that Fe-La@ZE has a developed pore structure and Fe and La are successfully loaded into the interior and surface of the zeolite support, which are in the form of α-Fe₂O₃ and La₂O₃. The COD removal rate of zeolite adsorption, ozone oxidation alone and catalyzed ozone oxidation with empty zeolite support are 4.9 %, 46.5 % and 57.5 %. The removal rates of COD, total phenol and 2,4-dichlorophenol by catalytic ozonation under the conditions of pH = 0.89, ozone dose of 0.2 g/L, catalyst filling rate of 10 % and height to diameter ratio of the reactor 6:1 are 84.2 %, 87.8 % and 99.0 % respectively. Hydroxy radicals (OH) and superoxide radicals (O2) are the main active substances that catalyze the degradation of 2,4-dichlorophenol in the ozone oxidation system. Water quality characterization shows that most phenolic organic compounds and macromolecular organic acids are broken down and converted into intermediate products. The comprehensive analysis model of entropy gray clustering is used to evaluate the operating condition data of the catalytic ozonation treatment of 2,4-dichlorophenoxyacetic acid wastewater with the Fe-La@ZE catalyst and determine the optimal operating condition.