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Prediction of Carbofuran Degradation Based on the Hydroxyl Radical’s Generation using the FeIII impregnated N doped-TiO2/H2O2/Visible LED Photo-Fenton-like Process
摘要： Hydroxyl radicals (?OH) are the dominant reactive species during most photocatalytic reactions. Therefore, ?OH generation as an index could be beneficial in comparing the obtained results in different experimental setup designs, thereby providing new insights for understanding the photocatalytic mechanism. Heterogeneous Photo-Fenton like processes are one of the most effective technologies for degradation of organic pollutants through ?OH production. Nevertheless, kinetic models that take into account the dependence of the contaminant degradation on ?OH generation under homogeneous oxidant supply, are still limited in such processes. In this paper, a photo-Fenton like reagent (FeIII impregnated N-doped TiO2 (FeNT)/H2O2) involving both heterogeneous and homogeneous phases was employed for carbofuran (CBF) degradation, frequently used pesticide in many developing countries from the carbamate group. In addition, a commercial visible LED lamp (Vis LED) with high power output was utilized as an innovative and efficient visible light source to simulate solar energy. Accordingly, a new kinetic model was proposed to predict CBF degradation in the FeNT/H2O2/Vis LED process under high Vis LED light intensities based on intrinsic reaction parameters, including the Vis LED light intensity, FeNT dosage, initial H2O2 concentration, and ?OH generation. The developed model was verified and validated successfully under various reaction conditions. However, a standard error ranging from 3 % to 15% was observed at extreme cases such as high [FeNT] and I or low [H2O2]0 when comparing model predictions and experimental results. This is due to the use of averaged conditions to forecast the rate constants.
关键词： Fe-N doped TiO2,Hydroxyl radicals,kinetic modeling,Carbofuran,Visible LED,impregnation
更新于2025-09-16 10:30:52
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Removal of Carbofuran in aqueous solution by using UV-irradiation/hydrogen peroxide
摘要： Pesticide residues in natural water are one of the biggest environmental problems. carbofuran is an insecticide widely used in agricultural activities and it is easily biodegradable. Although this compound has a relatively short lifetime in soils and its persistence in the environment varies from one to several weeks. For this reason, the elimination of carbofuran residual from contaminated waters using suitable technique is of environmental interest. The aim of this study to investigate the synergetic effect of UV and UV with hydrogen peroxide on the degradation of carbofuran in aqueous solution. 50 mgL-1 aqueous solutions of carbofuran (CBF) were prepared. The solutions were exposed to various UV irradiation times. The irradiation time varied from (15-240 min). Hydrogen peroxide was set at 4.8 mM as a minimum concentration level. To follow the degradation percent, formaldehyde concentration, and to identify the intermediates by-products, GC-MS, IC, and UV-Visible spectrophotometer were used. The pH, total acidity, and dissolved oxygen values were determined before and after treatment with UV irradiation with/without hydrogen peroxide. Depending on the results obtained the mechanism pathway (degradation) was suggested. The complete removal of carbofuran in aqueous solution took place at 180 min in the presence of H2O2.
关键词： advanced oxidation processes (AOP’s),hydrogen peroxide effect,Carbofuran,UV/H2O2
更新于2025-09-10 09:29:36