【作者】 李君；

【导师】 官宝红；

【作者基本信息】 浙江大学 ， 环境工程， 2006， 硕士

【摘要】 运河水系是杭州的文化、景观、交通脉络。1980’s以来，由于忽视运河的保护，致使其水质退化。进入1990’s，大规模的运河整治活动持续不断，有机污染有了明显的好转，但是富营养化污染却没有得到遏制。运河水系的环保治理必将从有机污染控制转向富营养化污染的控制与治理。而底泥作为河流的组成部分，是营养物质氮磷的重要蓄积库，在一定条件下，内源氮磷负荷可释放到水体中，加剧富营养化程度或者延缓水体功能的恢复。本文通过大量的实地调查和分析，评价了运河水系水体氮磷的污染状况和沉积物磷污染情况，并以内源磷为研究对象，在模拟河道中研究了水力条件对内源磷释放及各形态磷稳定性的影响，建立了相关的模型。 对运河水系水体的调查表明，氮磷污染严重，特别是氮污染远超出了Ⅳ类水质标准；磷污染情况虽有所减轻，但氮磷比值远超过7.2，说明磷是影响杭州市内河富营养化的限制性营养物质。 以东新河为例，底泥底泥中磷富集浓度较高，平均值为1.5g／kg，无机磷的主要存在形式都是与铝或钙结合状态的无机磷；污染源多为生产污水的底泥中金属附着态的磷较多，无机磷无机磷占TP比例大；而排污口接纳生活污水较多的底泥中钙结合态的磷较多，且无机磷比例较小。 利用地统计学方法和GIS相结合生成排污口和采样点空间分布的点状矢量图，说明点源污染对底泥磷负荷的贡献明显，底泥中磷浓度与排污口多少、污水中磷浓度及接纳污水性质都有明显的关系。 底泥释磷的水动力学研究表明，水流速度对释磷起主导作用，随流速增大，释磷量增大，但释磷量最大的模型流速出现在0.008m／s时；上覆水深、污染物本底值高的上覆水均能促进底泥释磷；释放的主要形态依次是铁磷、铝磷和钙磷；最后通过模型测算出底泥磷浓度在原型流速下向水体释放磷的速率。 研究表明，杭州运河水体的氮、磷污染比较严重，底泥中磷浓度高且磷的存在状态与排污口水质有一定关系；河道的水流速影响底泥释磷，可以根据本文提出的控制流速来抑制底泥释磷或者强化底泥释磷。更多还原

【Abstract】 The Great Canal is the culture lightscape and traffic venation of Hangzhou city. Since the 1980’s, water quality of the Great Canal had degenerated as a result of the long-term negligence of environment protection. Thanks to the environment protection for the Great Canal since the 1990’s, organic pollution has been decreased obviously, but the eutrophication has not been controlled effectively. Eutrophication control will take the place of organic pollutant removal to become the most important way of the Great Canal treatment. As a substaintial component of river, the sediments are important storeroom of N and P. Under certain conditions, the internal Phosphorus can be released into water which can deteriorate the eutrophication or hamper the restoration process. Coupled with analysis of historical data and field survey, the evaluation of the N and P pollution in water and P pollution in sediments were undertaken. At the same time, taking internal P as object, hydrodynamics effect on the release and stability of different P forms was studied and a relative model was established based on it.The investigation results of pollution status of N and P in the Great Canal indicated that the pollution was serious, especially for N, whose indicator far exceeded the standard of IV water quality classification. Although P pollution was lightened to a certain extent, the N/P index went beyond 7.2 far away which demonstrated P as a restricted factor for eutrophication in Hangzhou city’s rivers.The P accumulation of sediments in Dongxin river was at a high value, whose average value was 1.5g/kg. The major forms of inorganic P were Al-P or Ca-P. More Fe-P or Al-P was found in the sediment with the productive waste water as the major input, but for the sediment with the domestic waste water as the major input, Ca-P was the main form.Geostatistics and GIS were integrated to produce point vector graphs for spatial out-fall and sediment samples distribution. The results showed that point-pollution made significant contribution to P loading in sediment whose concentration has notable relationship with the number of out-fall, P concentration in polluted water and更多还原