Lemna (duckweed) as an indicator of acid water.

浮萍是一种对重金属和其他水污染物非常敏感的植物。此外，由于它的体积小，增殖速度快，它是有用的实验。我们已经做了很多尝试，使用浮萍作为指示物种检测水污染。本课题对浮萍作为酸性水体指示剂的应用进行了研究.浮萍在不同pH值下的生长和增殖研究表明，浮萍在pH值为4 - 6的培养基上生长和增殖最有效。浮萍在pH3.6的培养基上不能生长，24小时内死亡.不同pH条件下浮萍对重金属的吸收作用浮萍对重金属的敏感性受介质pH的影响，高pH值的介质使浮萍对重金属更敏感。浮萍属植物对重金属的吸收和积累能力强，对重金属的敏感性高.浮萍在河水和雨水上的生长当浮萍生长在雨水上时，浮萍的生长速度是如此之小。在pH值较高的培养基上生长速率较大，在河水和污水中的生长也受中等pH值的影响。

Lemna is a plant very sensitive to heavy metals and other water pollutants. Furthermore, it is useful for experiments because of its small size and rapid multiplication rate. We have made many attempts to use Lemna as an indicator species for the detection of water pollution. In this project, the study on the utilization of Lemna as an indicator of acid water was made.1. The Growth and the Multiplication of Lemna under various pHIt was made clear that the growth and the multiplication of Lemna were made most effectively on the medium adjusted to pH4 - 6. When Lemna was planted on the medium of pH3.6, it couldn't grow and died within 24hrs.2. The Absorption of Heavy Metals under Various pHThe sensitivity of Lemna to heavy metals was affected by medium pH. The high pH value of the medium affected Lemna more sensitive to heavy metals. And it was shown that more absorption and accumulation of heavy metals resulted in the high sensitivity to heavy metals of Lemna.3. The Growth of Lemna on the River Water and on the Rain WaterWhen grown on the rain water, the growth rate of Lemna was so little. The growth rate was larger on the medium of higher pH value.Growth on the river water and on the sewage water were also affected by medium pH.