水库泄洪闸下溪流深潭氮磷营养盐滞留特征及动力学模拟

为解析水库泄洪闸下溪流深潭氮磷营养盐滞留特征，选择NaBr为保守示踪剂，分别以NH₄Cl和KH₂PO₄为添加营养盐，在合肥板桥河源头溪流开展野外示踪实验，据此估算氨氮（NH₄⁺）、磷酸盐（PO₄^3-）营养螺旋指标，识别主流区和暂态存储区NH₄⁺、PO₄^3-滞留贡献水平，模拟深潭地貌的氮磷吸收动力学特征.结果表明，深潭具有较好的氮磷滞留潜力，且对PO₄^3-的滞留潜力超过NH₄⁺；暂态存储区对NH₄⁺的滞留贡献率平均为91.49%，表明NH₄⁺滞留主要发生在暂态存储区；主流区对PO₄^3-的滞留贡献率平均为96.09%，意味着主流区是PO₄^3-滞留的主要场所；Michaelis-Menten（M-M）方程可以较好的模拟深潭氮磷滞留动力学效应，模拟得到的最大吸收速率U_max-NH₄、U_max-PO₄均值分别为0.48、0.08 mg·m^-2·s^-1，半饱和常数K_m-NH₄、K_m-PO₄均值分别为0.26、0.19 mg·L^-1.

Retention characteristics and kinetics simulation of nitrogen and phosphorus in a stream pool under the sluice gate of a small reservoir

To investigate the retention characteristics of nitrogen and phosphorus in natural deep pool geomorphic pattern of streams, several field tracer experiments by taking NH₄Cl and KH₂PO₄ as nutrient additions, and NaBr as a conservative tracer were performed in the headwater stream of Banqiao River, Hefei district. The nitrogen and phosphorus spiraling metrics were measured, and the contribution of main channel and transient storage zone to NH₄⁺ and PO₄^3- retention were estimated, respectively. Moreover, dynamics simulation for nitrogen and phosphorus retention was conducted as well. Results showed that the deep pool had a good potential for nitrogen and phosphorus retention, and retention potential for PO₄^3- was higher than that of NH₄⁺. NH₄⁺ retention in transient storage zone was taken up to 91.49%, indicating that NH₄⁺ retention mainly occurred in the transient storage zone. PO₄^3- retention in main channel zone was up to 96.09%. In addition, Michaelis-Menten (M-M) equation could well simulate the dynamics of NH₄⁺ and PO₄^3- retention in the deep pool. The mean maximum uptake rates of U_max-NH₄ and U_max-PO₄ obtained from the M-M equation were 0.48 and 0.08 mg·m^-2·s^-1, respectively. And the half-saturation constants K_m-NH₄ and K_m-PO₄ were 0.26 and 0.19 mg·L^-1, respectively.