微曝气垂直流湿地污染物去除动力学模型分析

通过对自主研发的微曝气垂直流湿地系统长期运行观测数据的统计分析,在参考填充塔模型基础上,利用质量衡算方程建立了微曝气垂直流湿地污染物去除动力学模型,并利用该模型对湿地在气水比分别为0.5:1、1:1、2:1和3:1时的污染物去除效果和去除动力学常数k值进行了计算和分析.结果表明,在处理水质稳定、水量恒定的情况下,微曝气垂直流湿地对各种污染物的去除过程动力学常数k值均随工艺参数气水比的增大而增大,即对污染物的去除能力随气水比的增大而增强;各水质指标的反应动力学常数变化曲线形状有所不同,动力学常数与气水比的关系主要有线性关系和对数关系.综合各个水质指标的曲线形式与变化规律可以得到微曝气垂直流湿地的最佳气水比设计值为2:1,对应BOD5和NH4+-N的k值分别为3.8d-1和4.1d-1.

Dynamics Model Analysis of Pollutants Removal in Aerated Vertical-flow Wetland

Based on the dynamic model building of pollutants removal in aerated vertical-flow constructed wetland, data of the wetland under different aeration conditions were analysed. Different aeration conditions' k values were calculated, which represented the pollutants removal kinetic constants. The results demonstrate that the efficiency of pollutants removal is higher with the increasing gas-water ratio. The most favorable designing gas-water ratio of the aerated vertical-flow constructed wetland was chosen as 2 : 1 through analysis of curve fits by regression with kinetic constants values and gas-water ratio values. The corresponding k values of BOD5 and NH4(+) -N are 3.8 d(-1) and 4.1 d(-1) respectively.