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，倍增速度快，因此适合于实验。我们曾多次尝试将浮萍作为检测水污染的指示物种。本项目对浮萍作为酸性水指示剂的利用进行了研究。不同pH条件下浮萍的生长和增殖研究表明，在调节pH值为4-6的条件下，浮萍的生长和增殖效果最好。当浮萍接种在pH值为3.6的培养基上时，浮萍不能生长并在24小时内死亡。不同pH条件下浮萍对重金属的吸附研究浮萍对重金属的敏感性受介质pH的影响。较高的pH值影响浮萍对重金属的敏感性。结果表明，浮萍对重金属的吸收和积累越多，对重金属的敏感性越高。浮萍在河水和雨水上的生长当在雨水上生长时，浮萍的生长速度很小。PH值越高，生长速率越大，河水和污水中的生长也受到介质pH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.