| Summary: | 碩士 === 國立臺中教育大學 === 科學應用與推廣學系科學教育碩士班 === 100 === The research aimed to investigate dye degradation using the advanced oxidation treatments, including Fenton, Photo-Fenton, Photo-Fenton-like, and Fenton-like systems. There were eight homogeneous catalytic experiments containing the interactions between two types of dyes, Acid Blue 1 (AB1) and Ethyl Violet (EV), and four oxidation treatments. These methods apply the homogeneous catalytic experiments which yield powerful oxidization to degrade various types of dyes. The purpose is to evaluate the ability of degradation of AB1 and EV and assess the effects of different levels of reagent concentration and pH ratio from these four oxidation treatments respectively. In addition, the HPLC–PDA-ESI-MS is applied to separating and identifying the impact of ABI and EV on the degradation of generated intermediates. As a result, the possible degradation pathways can be inferred and argued in order to provide a stylized fact for the industrial dye wastewater.
The experimental results are shown as follows. (1) The optimum AB1 degradation are 0.5mM FeSO4 and 10m MH2O2 during Photo-Fenton and Fenton; and 2mM Fe(NO3)3 and160m MH2O2 during Photo-Fenton-like and Fenton-like. (2) The optimum EV degradation are 0.5mM FeSO4 and 5mM H2O2 during Photo-Fenton and Fenton; and 2mM Fe(NO3)3 and 160mM H2O2 during Photo-Fenton-like and Fenton-like. (3) The optimum pH is about 3 regardless of different oxidation treatments.
Regardless of AB1 or EV in the Photo-Fenton, Fenton (Photo-Fenton-like, Fenton-like), requiring very high wattage 254nm UV irradiation effect, can be significantly presentedin the light. Generally speaking, the degradationexperiments show that Photo-Fenton and Fenton treatments are more efficient than the Photo-Fenton-like and Fenton-like.
This research also utilizes the HPLC–PDA-ESI-MS for separating and identifying the impact of AB1 and EV in order to uncover the dye degradationpathways. The intermediates are generated by the degradation of AB1 and EV under Photo-Fenton. However, the AB1 with a very small amount of oxidant (H2O2) efficiently accelerates the degradation, leading to rapid Benzene ring-opening reactions, such that few intermediates are found. In addition, the results indicate that the probable degradation pathways are Dealkylation and Hydroxy-lation of chromophore, and cleavage of the conjugated chromophore structure. The findings provide the fundamental applications of photocatalyst to dye degradation.
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