| Summary: | 碩士 === 嘉南藥理大學 === 環境資源管理系 === 105 === Imidacloprid (IMD) is a new type of the insecticides widely used in agriculture and residential properties. Wastewater containing IMD can harm human and aquatic lives. This study applied the fluidized-bed Fenton process to remove IMD because of its low capital cost, easy operating, non-toxic by products. Degradation of IMD was investigated in a lab-scale reactor with synthetic wastewater. Studied conditions were pH 3, 1.0-10.0 mM of Fe2+, 1.0-20.0 mM of H2O2, 1.0 mM of IMD, and 100 g SiO2. It was found that the Fe2+:H2O2 ratio was a significant operating factor on IMD degradation and the optimum ratio was 3:5. Increasing H2O2 concentration could improve IMD degradation; however, excessive H2O2 caused scavenging effects and decreased IMD degradation as a consequence. When the initial Fe2+ concentration increased, the IMD and H2O2 degradation efficiency also increased rapidly. Scavenging of OH•, which is indicated by a negative effect of Fe2+ concentration, was not observed in all the Fe2+ dosages used in this study. Under the appropriate conditions, the degradation efficiency of IMD of 97.07% IMD, 41.38% COD and 12.04% TOC, while the removal efficiencies were in the following order: IMD > COD > TOC could be obtained in 45 minutes of the reaction time. Overall kinetic equation for IMD degradation by fluidized-bed Fenton process can be dedcribed as:
(d[IMD])/dt = 〖-0.2323〖 [H_2 O_2]〗^0.1065 [〖Fe〗^(2+)]〗^0.3618
Increasing bed expansion did not a significant difference in Fe2+ removal and IMD degradation but have an effect on iron while it reducing ferric hydroxide sludge.
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