Study On The Kinetic Model Of PCE Degradation In Fenton-like System Based On Iron Ore/H₂O₂

Chlorinated hydrocarbons are the most common volatile organic compounds in the environment that are more harmful and difficult to be biodegraded.Vinyl chloride is a key removal target because of its high toxicity and high content.In recent years,advanced oxidation technology has attracted the attention of many scholars due to its efficient degradation of target pollutants.Fenton technology has received extensive attention because of its low cost,low environmental toxicity,and efficient removal of pollutants.However,traditional homogeneous Fenton Due to strict application conditions and difficulty in recycling,Fenton-like technology has gradually been developed and applied.From the perspective of the development of solid catalysts,Fenton-like systems range from the initial single iron-based catalysis,improved bimetallic catalysis,synthetic metal-organic framework catalysis,adding non-metallic component catalysis,etc.,to the application of aluminum,copper and other non-iron-based catalysis In recent years,the improvement of materials science has developed a single atom catalytic form.In this project,PCE was selected as the target degradation product.The experimental results of PCE degradation by classic iron-based Fenton-like reaction,combined with data processing and mechanism analysis,were used to construct a kinetic model of PCE degradation for engineering in practical application.The selection of parameters provides the basis.First,goethite and wurtzite were prepared as catalysts under laboratory conditions,and the specific surface area and pore size of iron ore were determined through characterization experiments.Subsequent experiments on the influencing factors of PCE adsorption by iron ore and the adsorption rate fitting under different conditions show that PCE adsorption at iron ore sites belongs to quasi-second-order kinetic adsorption,and the surface complex theory should be used for the analysis of adsorption behavior.The CD-MUSIC model is used to describe the surface active adsorption sites of iron ore containing single and triple coordination O（H）groups(≡FeOH^-0.5,≡Fe₃O^-0.5),and the single coordination group can be considered as PCE The main reason for adsorption is to construct the relationship between the concentration of PCE in the water-phase adsorption phase through the principle of mass balance,and use the SS/SF mixed theory model to make a mathematical description of the kinetic behavior of iron ore adsorption of PCE.In the experiment of the factors affecting the degradation of PCE by iron ore/ H₂O₂ Fenton system,the effect of PCE on the kinetic parameters of PCE degradation under different iron ore dosage,initial p H value and H₂O₂ dosage concentration can be seen The degradation conforms to the quasi-second-order kinetic law,and the reliability of the regression model under different conditions is proved by residual analysis.PCE had the highest removal rate when the iron ore dosage was 3.34g/L,p H=6,and H₂O₂ concentration was 6.67g/L.The removal effect was positively correlated with the oxidant concentration and iron ore dosage within a certain range.Through the study of the mechanism of catalytic decomposition of H₂O₂ and degradation of PCE by Fenton-like system,the generation process and concentration calculation formula of free radicals were analyzed.Through experimental comparison,it can be seen that adsorption and iron ion dissolution have little effect on the degradation of PCE.Finally,the degradation kinetic model of PCE in Fenton-like system is constructed,and the fitting degree is more than 98% compared with the experimental data,which proves the correctness of the model.