【作者】 邓焕广；

【导师】 陈振楼； 许世远；

【作者基本信息】 华东师范大学 ， 环境科学， 2005， 硕士

【摘要】 近年来,我国滨岸环境状况不容乐观,赤潮频繁发生并且发生的规模不断变大(在河口海洋地区赤潮的主要限制因素是氮)。除每年由河流从内陆带来大量营养盐外,滨岸带建设的大量排污口(如污水排放口、垃圾填埋后产生的垃圾渗滤液的排放口)向海洋排放的污染物质中含有营养盐的量也不容忽视。随着城市的发展,人口不断的增长和人民生活水平提高,生活垃圾年产量以5%～10%的速度增长,而大部分垃圾处理是以填埋为主,在垃圾填埋过程中及填毕封场后产生的一种高浓度、多组分难处理的废液——垃圾渗滤液,处理不当会引起地表水、地下水、土壤等的严重污染。 垃圾渗滤液的排放对滨岸带的水体环境和环境介质间的物质循环有着重要影响。潮滩沉积物是河口生态系统中氮、磷和重金属的主要归宿,在河口营养状况的控制和营养盐循环过程中均扮演着重要的角色,垃圾渗滤液中携带的污染物质累积在沉积物中。潮滩通过物理、化学和生物过程,对进入上覆水体和沉积物中的营养盐进行净化,而重金属则积累在沉积物中。在一定条件下这些污染物质被释放出来,造成二次污染。潮滩生态环境脆弱,大量污水的排放会对生态环境造成严重的影响。因此,通过研究渗滤液的排放对潮滩产生的环境效应及通过老港潮滩营养盐界面通量估算出潮滩对受污海水的净化能力,具有重要的现实意义和科学意义。 选择经济发达的长江口附近的垃圾填埋场处潮滩为研究对象,开展垃圾渗滤液对潮滩环境的影响及潮滩对垃圾渗滤液净化的研究,不仅可以丰富和发展河口滨岸生物地球化学理论,而且可为长江口及我国其他河口环境保护和富营养化控制管理提供可靠的科学依据。 通过大量的野外采样、观测和实验室模拟、分析工作,本论文主要在以下几个方面取得了主要的研究进展: 1.垃圾渗滤液的排放老港潮滩上覆水和沉积物中营养盐含量明显高于对照点,成为长江口滨岸营养盐的高蓄积区;局部污染表现为由排污口向外呈辐射状降低,但在高中潮滩交界和低潮滩污染又有加重的趋势。 2.老港潮滩沉积物中重金属含量均明显高于环境背景值,也明显高于崇明东滩。从高潮滩到低潮滩,沉积物中重金属的含量依次降低,但在高、中潮滩交界处出现重金属污染的严重区域。老港和白龙港潮滩沉积物中重金属随深度变化可以体现污水排放的状况及沉积物重金属的污染状况。经过初步的判源发现:老港潮滩沉积物中重金属主要垃圾渗滤液的影响。更多还原

【Abstract】 In recent years, the coastal environment in our country is getting worse: red tide breaks out frequently and its scale is continuing becoming larger, as it’s known, nitrogen is the main limit factor of the eutrophication in estuaries and coastal seas. Besides the large amount of nutrient brought by rivers from the continent, the content of nutrient in the sewage discharged by the sewage outfalls which are constructed along the coastal area can’t be neglected. With the development of cities, increase of the population and the rising of the living standard of people, the annual production of the garbage are increasing at a speed of 5% to 10%. Garbage fill and deposit is the popular and main way to deal with the garbage. But a kind of waste liquid named as garbage leachate will be produced during this process and also after the garbage is filled and deposited. The garbage leachate will pollute the surface water, groundwater and soil significantly if it can’t be treated properly.Constructing garbage landfill near coastal area is very prevalent due to its great economic profit, but the garbage leachate let off from the landfill has a significant influence on the coastal water quality and the substantial cycling between different environmental medium. As the main sink of N, P and heavy metals in the estuary ecosystem, intertidal sediment play an important role in the eutrophication control and nutrient cycling process in the estuary. Various kinds of pollutants including N, P, and heavy metal et al. in the garbage leachate accumulate in the sediment, in which the intertidal sediment will decontaminate the nutrient through different physical, chemical and biological processes, while the heavy metals will accumulate in the sediment gradually, and will release to the environment under some specific conditions, leading to the secondary pollution. So it has important realistic and scientific meanings to study the environment effect on the tideland caused by the discharged sewage and calculate the decontamination capability of the tidal sediment to the polluted sea waters through the computation of the nutrient interface exchange fluxes of the tideland near the sewage outfalls.Choosing the tideland near the leachate outfalls in the developed Yangtze estuary, the influence of the leachate outfalls on the tidal environment and the decontamination mechanism of the tideland to the garbage leachate have been studied in this dissertation. This research will not only enrich and develop thebiogeochemistry theories in the estuary and coastal zone, but also provide reliable scientific basis for the environment protection, the eutrophication control and management of the Yangtze estuary as well as other estuary in our country. Through a large amount of field sampling and observation, experimental simulation and analysis, we get several main conclusions as follows:1. Due to the influence of the discharged leachate along the coastal zone the nutrient content in water and sediment of LG are higher than that in CM, and these tidelands have become a high deposition area of pollutants in Yangtze estuary. The partial pollution generally decreases with the distance to the sewage outfall, except that in low-tideland the pollution has a rising trend.2. The concentrations of the heavy metals in the sediment of LG which are influenced by leachate are higher than the environmental background values, and also higher than CM. The heavy metal pollution is serious in LG. The content of heavy metals in superficial sediment of LG decreases with the distance to the sewage leachate outfall, except that in the area between high-tideland and mid-tideland, the heavy metal pollution in the sediment is very serious. The content of heavy metals in the core sediment of tideland near the sewage outfall changes with the depth regularly to some extent, which can reflect the discharge situation of the sewage in a short period and the heavy metal pollution levels in sediment. By primary analysis, it’s found that the heavy metals and nutrient in the sed更多还原