香根草对不同形态氮吸收动力学特性研究

Study on uptake kinetic characteristics of different ammonium and nitrate by vetiveria zizanioides

对香根草不同形态氮素吸收动力学特性进行了研究,其吸附曲线均符合Michaelis-Menten酶动力学方程,采用Hofstee转化式对实验数据进行处理,得出以下结论:1)香根草对铵态氮的亲和力小于对硝态氮的亲和力(Km铵态氮<Km硝态氮),说明香根草有优先吸收硝态氮的趋势;2)香根草对铵态氮的最大吸收速率Vmax为6.3479μmol·g-1·h-1,对硝态氮的最大吸收速率Vmax为2.2219μmol·g-1·h-1,Vmax铵态氮>Vmax硝态氮,表明香根草对铵态氮的净化速率大于对硝态氮的净化速率;3)对于富营养化水平较高的水体修复,香根草具有更高的效率,可以将Michaelis-Menten动力学模型应用于不同营养化水体修复植物的选择.

This paper studies on uptake kinetic characteristics of different ammonium and nitrate by vetiveria zizanioides.The results showed that：（1）the kmvalue of ammnium uptake was bigger than that of nitrate uptake by vetiveria zizanioides（Km ammonium＞Km nitrate）,which indicated that the vetiveria zizanioides prefer ential uptake and clean up nitrate; （2）The maximum rate of ammonium uptake by vetiveria zizanioides was larger than that of nitrate uptake and the maximum rate of ammonium was 6.3479 μmol · g-1 · h-1 and the maximum rate of nitrate was 2.2219 μmol · g-1 · h-1,which indicated that the purification rate of the ammonium was bigger than nitrate; （3） The vetiveria zizanioides has higher efficiency for high eutrophication level of water body restoration,and Michaelis-Menten model is applied in plant selection.