粉绿狐尾藻和凤眼莲对不同形态氮吸收动力学研究

KINETICS OF AMMONIUM AND NITRATE UPTAKE BY MYRIOPHYLLUM AQUATICUM AND EICHHORNIA CRASSIPES

采用改进常规耗竭法,研究了粉绿狐尾藻(Myriophyllum aquaticum)、凤眼莲(Eichhornia crassipes)在抑菌和非抑菌两种处理中对NO3-、NH+4吸收的动力学特征。结果表明:两种植物对NO3-和NH+4的最大吸收速率(Imax)和亲和力(1/Km)有显著差异,凤眼莲对NO3-、N H+4的吸收速率显著高于狐尾藻,说明凤眼莲更适宜用于污染水体养分的去除;不同植物对NO3-、NH+4表现出吸收偏好性,凤眼莲对NO3-有较高的Imax值和亲和力,而狐尾藻对NH+4有较高的Imax值和亲和力;抑菌处理能显著增加凤眼莲对NH4+的吸收速率,NO3-浓度高于1.00 mmol/L时,抑菌处理能显著减小凤眼莲对NO3-的吸收速率,狐尾藻对NO3-、N H4+的吸收未受到抑菌处理的显著影响。

The nutrient uptake kinetics of M.aquaticum and E.crassipes were investigated by using the modified de-pletion method under nutrient solution of antimicrobial treatment and non-antimicrobial treatment.The maximum up-take rate（Imax） and Michaelis-Menten constant（Km） were estimated by iterative curve fitting.The Imax and Km for the plants was significantly different between two plants.The absorption rates of and in E.crassipes were significantly higher than that in M.aquaticum,illuminated that M.aquaticum was proper for treatment of the seriously polluted water.The Imax and 1/Km for was higher than that of in E.crassipes.In contrast,The Imax and 1/Km for was higher than that of in M.aquaticum.In E.crassipes,the absorption rates of in an timicrobial treatment were significantly higher than that in non-antimicrobial treatment,and the absorption rates of in antimicrobial treatment were significantly lower than that in non-antimicrobial treatment when the concentra tion of was higher than 1.00 mmol/L.There were no difference between antimicrobial treatment and non-antimicrobial treatment for the absorption rates of and in M.aquaticum.