富营养化与污染物间的相互作用及其生态效应

1　引　言进入 90年代 ,为了改善水环境条件 ,越来越多的国家认识到必须减少养分、稳定的有机物和金属元素的输入。富营养化和持续污染物 (Ｃｈｒｏｎｉｃｐｏｌｌｕｔａｎｔｓ)是当前全球水生态系统的两个主要问题1 ,2 ]。尽管对富营养化和污染物已有很多研究 ,但很少调查二者之间的相互关系。有证据表明两者之间可能存在相互作用过程5～ 7],但在自然的水生态系统中其作用的大小和关系尚不清楚。滇池是我国典型的遭受富营养化和重金属污染双重胁迫的高原湖泊 ,本研究以滇池富营养化和重金属污染为背景 ,通过室内模拟 ,初步探索富营养化和…

Mechanism and Ecological Effects of the Joint Action of Eutrophication and Heavy Metals

Orthogonal experimental methods were applied to study effects of the joint action of eutrophication(nitrogen and phosphorus) and heavy metals(cadmium, lead and copper, zinc,chromium, arsenic etc.) pollution on growth and accumulation of the elements in Lemna minor L. and the desorption of elements in sediment by the cultivating test. And it is tried to find the principle of the combined pollution of eutrophication and heavy metals. The results showed that accumulation of the heavy metals in the plant mainly depended on the concentration in the water, and also depended on the nutrient level and co-existing elements of the water. High level of the nutrients could increase the primary production and partly low the toxicity of the heavy metals. The desorption of heavy metals in sediment obviously varied with the nutrient level in the water and with effctive order of Cd>As>Pb>Zn>Cr>Cu. There were certain correlations among the elements.