【作者】 崔博；

【导师】 邬红娟；

【作者基本信息】 华中科技大学 ， 环境科学， 2005， 硕士

【摘要】 水体富营养化已成为全球环境问题的研究热点,对富营养化水体的治理日益迫切。但富营养化防治是水污染治理中十分棘手而又代价昂贵的困难问题。在水生态系统,浮游植物的生长不仅受到营养盐等环境因子的影响,而且受到生物因素的控制。这提供了一种可能:可以通过改变水体生物群落结构来减少浮游植物的现存生物量(standing crop),从而避免富营养化的危害,达到改善水质的目的。这种方法叫做“生物操纵”(biomanipulation)。本试验应用生物操纵原理,研究了通过改变水体中大型无脊椎动物——三角帆蚌的数量和密度来操纵水体中浮游植物的数量和群落结构,进而降低水体中营养盐浓度,提高水体的透明度,改善水质。这部分研究工作隶属于国家863计划——武汉汉阳水专项“受污染城市水体修复技术与工程示范”项目,由于生物试验的周期较长,本次试验结论仅是部分阶段性的成果。主要研究结果如下: 1)以莲花湖湖水为试验水样,进行试验。投放一定量的三角帆蚌,利用水生态系统食物链,摄取浮游植物,改善水质。从室内试验结果可以看出,利用三角帆蚌净化富营养化水体是可行而有效的。2)从动态试验的结果可以看出,三角帆蚌对水体中TP以及叶绿素a含量有很高的去除率。3)三角帆蚌的投放使浮游植物群落结构发生变化。处理围隔中浮游植物不管是在属还是在种类方面都比空白围隔有所提高。优势种由微囊藻演变为其他种类,如月芽藻、栅藻、微小四角藻。处理围隔中大于150μm和50-150μm级别的种类所占总种类的百分比明显比空白围隔降低,10-50μm级别所占的百分比升高,而且出现了小于10μm级别的种类。经三角帆蚌处理后的水样,浮游植物有朝小型化发展的趋势。本研究的结果证明,通过放养适当密度的三角帆蚌的生物操纵方法对于控制湖泊水华是可行的。本研究结果为改进湖泊控藻措施,强化控藻效果提供了重要的参考资料。更多还原

【Abstract】 Eutrophication has become a hotspot for the research of worldwide environment. It’s urgent for remediation. However, prevention and cure of it is not only intractable but also expensive during the remediation of water pollution. In the water ecosystem,the growth of phytoplankton are not only influenced by environment factors, but also controlled by biotic factors. This shows a kind of possibility that the standing crop of phytoplankton can be decreased by changing biotic community structure. this way avoids the danger of eutrophication, and reaches the aim of improving the quality of water. It can be named as biomanipulation. On the base of classical biomanipulation principle, this experiment studied by changing quantity and density of benthos i.e. Hyriopsis cumingii to control the quantity and community structure of phytoplankton. It decreased the concentration of nutrient content, increased transparence, and improved water quality. This research subjected to National Plan 863-“The demonstration of restoration project to the eutrophicated water of Wuhan city”. Because of biotic tests usually need a long period, this results are partly phasic achievement of the research. Following are the main results: 1)Taking sample water from Lianhua lake, putting some Hyriopsis cumingiis into the water.The experiment shows that purifying eutrophiced water by Hyriopsis cumingii is feasible and effective. 2)In order to prove that Hyriopsis cumingii have remediation effects on the eutrophiced Lianhua lake, a medial-scale experiment was carried out on the surface of the lake. The results show that the removal rates of TP and chorophyll-a were high. 3)The medial-scale experiment showed that the species composition,the dominant genus,biomass and other parameters of phytoplankton have been greatly influenced upon the input of Hyriopsis cumingiis. Phytoplanktons in the treated enclosure are more than that in blank enclosure regarding to the species and genus. .the dominant genus changed from Microcystis to the others,such as Selenastrum Reinsch、Scenedesmus Mey、Tetraedron minimum(A.Br.)Hansg. evidently, the percentage of species in treated enclosure in class 150μm and 50-150μm is lower than that in blank enclosure, furthermore, it happens species small than class 10μm. phytoplankton in treated enclosure by using Hyriopsis cumingii seem to have miniaturization development trend. the experiment showed that the biomanipulation is applicable and effective with adequate density .the result of experiment offer a important reference data for controlling the phytoplankton.更多还原