| Summary: | 碩士 === 長庚大學 === 化工與材料工程學系 === 101 === In this research, nanoscale zero-valent iron (nZVI) was synthesized by sodium borohydride (NaBH4) and chloride tetrahydrate (FeCl2‧H2O) in a rotating packed bed (RPB) equipped with blade packings. The differences of physical properties between RPB-nZVI and commercial nZVI (AF-nZVI) were investigated. To compare the chemical properties, two kinds of nZVI used to degrade polyvinyl alcohol (PVA) with H2O2.
The FE-SEM and TEM images showed that AF-nZVI and RPB-nZVI were almost spherical and existed as chain-like aggregates. The average sizes of AF-nZVI and RPB-nZVI were 25.2 nm and 49.6 nm, respectively. The BET surface areas of AF-nZVI and RPB-nZVI were 24.2 m2/g and 16.3 m2/g, respectively. In addition, the XRD analysis revealed that AF-nZVI consisted of Fe0 and FeO crystal structures. However, only Fe0 crystal structure was observed in RPB-nZVI. The EDX analysis indicated that AF-nZVI and RPB-nZVI had Fe of 35.2% and 62.1%, respectively.
The experimental results of PVA degradation showed that the highest degradation efficiency of 93.8% using RPB-nZVI was achieved at pH 3, an nZVI dosage of 0.005 g/L, H2O2 concentration of 110-4 M, and 25℃. However, the same degradation efficiency using AF-ZVI was achieved at an nZVI dosage of 0.5 g/L with other same operating conditions. Therefore, RPB-nZVI exhibited a higher activity than AF-nZVI.
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