研究论文
李丽,于志强,冉勇,盛国英,傅家谟,彭平安,黄伟林.Pahokee泥炭腐殖酸的相对分子量分布特征及其对菲的吸附影响[J].环境科学学报,2004,24(4):587-594
Pahokee泥炭腐殖酸的相对分子量分布特征及其对菲的吸附影响
- Characteristics for the molecular weight distribution of the Pahokee peat humic acids and the effects on the sorption of phenanthrene
- 基金项目：国家自然科学基金项目(4007209440172105)
- 作者
- 单位
- 李丽
- 1. 中国科学院广州地球化学研究所,有机地球化学国家重点实验室,广州 510640; 2. 同济大学,海洋地质教育部重点实验室,上海 200092
- 于志强
- 中国科学院广州地球化学研究所,有机地球化学国家重点实验室,广州 510640
- 冉勇
- 中国科学院广州地球化学研究所,有机地球化学国家重点实验室,广州 510640
- 盛国英
- 中国科学院广州地球化学研究所,有机地球化学国家重点实验室,广州 510640
- 傅家谟
- 中国科学院广州地球化学研究所,有机地球化学国家重点实验室,广州 510640
- 彭平安
- 中国科学院广州地球化学研究所,有机地球化学国家重点实验室,广州 510640
- 黄伟林
- 土木与环境工程系,Drexel大学,费城 19104
- 摘要：使用切面流超滤方法,将Pahokee泥炭中分离出的腐殖酸分为具有不同相对分子质量的8个级分(UF1:<1k;UF2:1～3k;UF3:3～5k;UF4:5～10k;UF5:10～30k;UF6:30～50k;UF7:50～100k:UF8:>300k),表明该泥炭中的腐殖酸主要分布于几个高相对分子量级分中(UF5,UF6和UF8),可占所提取的腐殖酸质量的835%.体积排阻色谱的流出曲线说明可以通过超滤手段将腐殖酸这种复杂的、非均匀性的大分子物质分成相对均一的、窄相对分子量分布的分子.而两种方法所测相对分子量的差异可能与两个操作系统间不同的操作条件有关.各超滤级分的腐殖酸对菲的吸附实验说明相对分子量是影响腐殖酸吸附的一个重要参数;随相对分子量的增加,腐殖酸对菲的吸附及其非线性特征均增强.
- Abstract：The humic acids extracted from the Pahokee peat were separated into eight fractions by the tangential flow ultrafiltration with membranes of different pore size cutoffs (UF1:<1k; UF2:1～3k; UF3:3～5k; UF4:5～10k; UF5:10～30k; UF6:30～50k; UF7:50～100k; UF8:>300k). The results showed that the Pahokee humic acids were mainly composed of three high molecular weight fractions(UF5, UF6, UF8), accounting for 83.5% of the extracted humic acids. From the size exclusion chromatogram of the eight ultrafiltration fractions, it indicated that the heterogeneous humic macromolecules can be separated into relative narrow size and homogeneous molecules. The difference in the measured molecular weights by the tangential flow filtration and the size exclusion chromatogram may be resulted from the differences in operation conditions. From the isotherm sorption experiment of the eight humic acid fractions for phenanthrene, it showed that the molecular weights of the fractionated humic acids were an important factor in controlling the sorption of phenanthrene by the humic acid fractions. As the molecular weights increased, the sorption potential of phenanthrene by the humic acid fractions increased and exhibited more nonlinearity. This research will help to understand the role of humic substances in the environment, especially the movements and fates of hydrophobic organic pollutants.
- Key words：humic acid relative molecular weight tangential flow ultrafiltration size exclusion chromatography sorption
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