挥发性污染物苯在水气界面耦合扩散的浓度分布

Distribution of concentration of volatile pollutant benzene in water-air interface coupled diffusion

为研究苯水体泄漏后水气污染的浓度时空分布,利用挥发性污染物水气耦合扩散模型进行预测计算,预测结果与水槽实验相结合,准确地描述了苯在水气界面耦合扩散的浓度分布规律:沿水流方向(x轴)浓度随时间向前推移,距离投放点越远,浓度峰值越小,出现时刻越晚;沿水流深度方向(y轴)浓度分布关于投放点z=0.20 m纵断面对称,在水气界面和空间变化界面(水槽边缘)浓度出现极小值,随着挥发量的增加,浓度峰值出现的位置由水中推移至大气中;沿水流宽度方向(z轴)浓度由投放点向两侧推移。分析了亨利常数、水流速度及风速对苯耦合扩散浓度分布的影响。

To study the spatial and temporal concentration distribution after the spill of Benzene,the coupling diffusion model was used. Based on the experimental simulation and the coupling diffusion model,the law of concentration distribution was described. With an increasing of time, the concentration of Benzene was reduced along the flow direction. The farther away from the release point, the concentration peak appeared later and became lower. The concentration distribution was symmetrical on both sides of the z = 0.20 m vertical section and it appeared the minimum value in the water-air interface and at sink edge. With the increasing in the amount of volatiles,the concentration peak appeared from the water to the air. The concentration went to both sides along the flow width direction from the release point. The influences of Henry constant, water velocity and wind velocity were analyzed.