浒苔对NO3—N和PO4—P吸收动力学特征

The kinetics of PO4—P and NO3—N uptake by Ulva prolifera

摘要:

研究了浒苔（Ulva prolifera）对NO₃—N和PO₄—P吸收动力学特征。结果表明：（1）浒苔藻体密度与NO₃—N和PO₄—P的去除率成正比；（2）浒苔对氮、磷的吸收速率与介质中氮、磷含量可用MihcaelsiMenton方程来描述（R²>0.95）；（3）浒苔对NO₃—N和PO₄—P吸收速率与时间均呈幂函数关系（R^{2>0.96），并存在3个不同的生理阶段：在60 min内呈快速吸收阶段，最大吸收速率分别达到了250.43和5.82 μmol/(gh)，而在60~320 min内吸收速率变化相对缓慢，最大吸收速率为155.12和2.36 μmol/(gh)，在320~720 min内吸收速率基本接近平衡，此时浒苔对NO₃—N和PO₄—P的最大吸收速率为36.72和1.32 μmol/(gh)。该研究结果为探究浒苔爆发机制及其海洋生态效应评估提供了理论依据。}

Abstract:

This paper mainly studied the uptake kinetics of NO₃—N and PO₄—P by Ulva prolifera in laboratory. The results showed that: (1) The higher the density of algae, the higher removal efficiency on the NO₃—N and PO₄—P in Ulva prolifera is. When the algae density is 10g/L, the concentration of PO₄—P in the culture medium are 94.27 percent lower than the starting time after 6 h; (2) The absorption rates of U. prolifera on nitrogen and phosphorus can be described by the MihcaelsiMenton equation (R2> 0.95); The absorption rates of U. prolifera on nitrogen and phosphorus had a relationship with their contents in the medium. With increasing of NO₃ —N and PO₄—P concentrations in the medium, the absorption rates are at higher levels and eventually leveling off balance. When the concentrations of PO₄—P rise to 20 μmol/L, or NO₃—N rise to 45 μmol/L in the medium, the uptake rates both reached the maximum. (3) With the extension of time, there were three different stages for U. prolifera uptaking NO₃—N and PO₄—P: the first 60 min ,called rapid uptake stage , within the the maximum uptake rate of 250.43 and 5.82 μmol/(gh), respectively, while in the subsequent 60-320 min the changes of uptake rates are relatively slow, and with the maximum absorption rate of 155.12 and 2.36 μmol/(gh), respectively. After 320-720 min, the uptake rates are close to flat, the maximum absorption rates of U. prolifera are 36.72 and 1.32 μmol/(gh), respectively. This study provided a theoretical basis for exploring the mechanism of U. prolifera outbreak and its marine ecological effects assessment.