鉴湖底泥及其在环境中的作用

Bottom Mud in Jian Lake and Its Effect on the Environment

用来酿造绍兴黄酒的鉴湖湖水是洁净的,对厚度>2m的鉴湖底泥污染物含量及其变化规律的现状研究,发现底泥的存在是保证鉴湖洁净的一个重要因素。鉴湖底泥是一种淤泥质粘土,粘土矿物成分伊利石、绿泥石、高岭石等的吸附性能正决定了它具有净化水环境的作用。长年累月,鉴湖底泥表层积聚了大量的污染物,但是沿湖居住的农民一年一度“捻湖泥”(即把最表层底泥取上岸、作为肥料之用)的习惯做法,客观上恰排除了底泥在其表面含污染物过量、从而成为水体二次污染源的可能性。

In Jian Lake, there is thick-bedded bottom mud, which is a kind of puddly clay consisting of illite, chlorite, kaolinite and a tiny minority of peat fragment. These clay minerals possess the properties of surface absorption and ion exchange for heavy metal ions and other poisonous pollutants. Therefore, the bottom mud plays an important role in removing pollutants in Jian Lake and purifying the natural environment. The pollutant content in the bottom mud decreases with the increment of its depth in Jian Lake except chromium. However, the farmers living around Jian Lake scoop up every year the polluted surface layer of bottom mud and use it as fertilizer which hereby becomes no doubt the second polluted source to the water.