| Summary: | 碩士 === 明志科技大學 === 環境與資源工程研究所 === 100 === Tetrachloroethylene (PCE) and toluene are some of the most commonly found pollutants in soil and groundwater. Due to their hydrophobic characteristics, they tend to accumulate in soil. Hence, they could be removed through soil washing methods by enhancing their solubility in solution. This study attempts to access whether the solubility of PCE and toluene could be enhanced by aqueous compost with different maturity. Three different samples, 0-month bagasse raw material (0C), 3-month bagasse compost (3C), and 6-month bagasse compost (6C) were selected in this study. The characteristics of these three samples, such as dissolved organic carbon, molecular weight, the E4/E6 ratio of fulvic acid and humic acid, Fourier transform infrared spectroscopy (FTIR), and 13carbon nuclear magnetic resonance (13C-NMR) data were examined. The results show that the dissolved organic carbon and E4/E6 ratio decreased, while the molecular weight increased with compost maturity. The data of FTIR and 13C-NMR indicated that the carbohydrates and aliphatic compound were abundance at the early stage of composting process. In contrast, the aromatic compounds and carboxylic acid were dominant in the more matured compost. The solubility study demonstrated that 3-month compost sample enhance the PCE solubility most significantly, because 3-month sample had largest dissolved organic carbon content among three tested samples. The 6-month sample contained the greatest aromatic structure, and hence showed the greatest toluene solubility enhancement effect, because toluene had aromatic structure. The two compost samples could dissolve more PCE and toluene when compared with 0-month bagasse raw material, and the solubility enhancement effect increase with aqueous compost concentration. Overall, the results of this study demonstrated that aqueous compost solution could be used as cheap materials to enhance the solubility of hydrophobic pollutants in soil.
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