PTA生产废液在包气带中迁移的模拟研究

以一工厂PTA生产废液为研究对象,选择COD为PTA生产废液特征污染因子,通过静态吸附及土柱淋滤实验确定包气带土层粉质粘土对PTA生产废液中污染物质的吸附、生物降解及弥散系数,利用Hydrus-1D软件建立污染物在包气带中迁移的对流-弥散模型,预测其在包气带土层中的迁移规律.结果表明:包气带中粉质粘土对PTA生产废液中污染物质有吸附、降解等阻隔作用,但吸附、降解系数均很低,分别为0.256cm3/g 和0.0077d-1.因此当PTA生产废液的COD浓度为4000mg/L,蓄水池中废液深5m,定水头持续淋滤厚为10m的包气带时,11.76年潜水面处地下水中COD含量超标.

Simulation study of PTA production wastewater transport in vadose zone.

The PTA wastewater discharged from a factory is selected as the research object, COD is selected as the characteristic pollution factor of PTA wastewater. Static adsorption and soil column leaching experiment of silty clay were taken place to study the adsorption、bio-degradation and dispersion coefficient of PTA wastewater. The Hydrus-1D soft was used to build the Convection-Diffusion model to demonstrate the phenomena of PTA wastewater migration, to predict the regularity of PTA wastewater migration in vadose zone. The results indicated that the silty clay in vadose zone could adsorb、degrade and impede contaminant in PTA wastewater, but the coefficient of adsorption and degradation were very low, down to 0.256cm3/g and 0.0077d-1 respectively. When COD concentration is 4000mg/L, PTA wastewater is 5m deep in the tank and vadose zone is 10m thick, COD concentration will exceed standard after 11.76 years.