| Summary: | 碩士 === 大仁科技大學 === 環境管理研究所 === 105 === In this study, the sediments collected from sampling locations in Gaoping River and Donggang River basins were sampled from August, 2016 to May, 2017. The collected sediments sieved were was extracted by deionized water and acid or alkaline solution. The extract was neutralized by acid or alkaline solution and analyzed by filtration through 0.45μm membrane filter. The filtrate was analyzed by fluorescence spectrometry, ultraviolet light absorption spectroscopy and total organic carbon analyzer, which was used to investigate the variation of content and property of organic matter attached on the sediment in both basins. In addition, the parameters including fluorescence emission spectra (EEFM), humification index (HIX) and biological index (BIX) were used to explore the characteristics and origins of organic matter.
The results showed that according to UV absorption and EEFM, there were differences in the property of organic matter between acid extracts and alkaline extracts, which indicated that organic matter existing in sediment could dissolve in acid solution and alkaline solution. For acid extraction, the main components of organic matter in acid extract from sediment in Gaoping River basin were fulvic-like and himic-like organic matter, and for Donggang River basin, in addition to fulvic-like and himic-like organic matter, soluble microbial by-product-like organic matter was also the major component, which revealed the difference of organic matter of sediment in two basins. For alkaline extraction, the main component of organic matter of alkaline extract from sediment in two basins was himic-like substance, and the additional peak obviously appeared at 350-550 nm/350-650 nm in EEFM, which was little reported in other papers. In addition, HIX value was explored in alkaline extracts from sediment in two basins, the results showed that it appeared high humification in Gaoping River basin, and the upstream of Donggang River basin, Longdon Bridge and Chaozhou Bridge, also appeared high humification, but the downstream of Donggang River basin was low humification. According to BIX value in acid extracts from sediment in two basins, the organic matter of sediment in Gaoping River and Donggang River basins was mainly from the metabolic newborn organics of protozoa or bacteria in water.
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