河流底泥潜在硝化速率模型研究

为深入认识河流NH₄+-N的转化降解过程，以生物量、温度和c（NH₄+-N）这3项因子为对象，开展河流底泥潜在硝化速率模型研究.采集典型污染河流底泥样品，设置3个生物量梯度（高、中、低）、5个c（NH₄+-N）梯度（0.13、0.63、1.13、2.13、4.13 mmol/L）、4个温度梯度（15、20、30、40℃），测定不同条件下河流底泥潜在硝化速率，并进一步构建了潜在硝化速率模型，定量分析了生物量、温度和c（NH₄+-N）对潜在硝化速率的影响.结果表明:①生物量对底泥的潜在硝化速率有显著影响，高、中、低生物量条件下，河流底泥潜在硝化速率范围分别为0.10~0.26、0.03~0.16和0.02~0.07 μmol/h.②底泥潜在硝化速率随温度呈现指数增长，但高温具有抑制作用，各温度梯度下k（硝化速率常数）分别为5.9、9.3、18.1、10.6 μmol/（g·h），15~30℃范围内θ（温度校正系数）为1.074.③c（NH₄+-N）对潜在硝化速率的限制作用符合Monod方程，高、中、低生物量条件下K_s（半饱和浓度）的平均值分别为0.02、0.05、0.13 mmol/L.研究显示，潜在硝化速率模型较好反映了生物量、温度和c（NH₄+-N）对河流底泥潜在硝化速率的影响，为定量认识底泥硝化能力提供了有效手段. 

Study of Potential Nitrification Rate Model of the River Sediments

In order to understand the transformation and degradation process of NH₄+-N in rivers, the influence of biomass, temperature and c(NH₄+-N) on the potential nitrification rate were studied quantitatively through potential nitrification rate model of the river sediment. Sediment samples from typical polluted rivers were collected. Three biomass gradients (high, medium, low), 5 c(NH₄+-N) gradients (0.13, 0.63, 1.13, 2.13, 4.13 mmol/L) and 4 temperature gradients (15, 20, 30, 40℃) were set, and the potential nitrification rates were determined. The potential nitrification rate model was established, and the effects of biomass, temperature and c(NH₄+-N) on nitrification rate were quantitatively analyzed. The results showed that:(1) under the conditions of high, medium and low biomass, the potential nitrification rate ranged from 0.10 to 0.26 μmol/h, from 0.03 to 0.16 μmol/h and from 0.02 to 0.07 μmol/h respectively. (2) The potential nitrification rate of sediment increased exponentially with temperature. However, high temperature shows obvious inhibition effect. The nitrification rate constant k was 5.9, 9.3, 18.1 and 10.6 μmol/(g·h) at 15, 20, 30 and 40℃ respectively, and the temperature correction factor θ was 1.074 at the range of 15 to 30℃. (3) The limiting effect of c(NH₄+-N) on nitrification rate conformed to the Monod equation. The half-saturation concentration K_s was 0.02, 0.05 and 0.13 mmol/L under high, medium and low biomass respectively. The research suggested that the potential nitrification rate model can well reflect the influence of biomass, temperature and c(NH₄+-N) on the potential nitrification rate of river sediment, and can provide an effective means for quantification of nitrification capacity of sediments.