河流–地下水系统水体污染研究

Research on Water Pollution in River Groundwater Systems

摘要: 水资源作为生产生活的必需品，在地下水污染中最难治理和危害最大的是有机污染，因而对有机污染物在河流–地下水系统中的行为特征进行研究具有十分重要的理论意义和实际价值。首先使用雷诺平均Navier-Stokes方程建立并模拟河流–地下水系统中有机污染物的对流、弥散及吸附作用的数学模型，得出在河流–地下水系统中，随着时间的变化有机物对流、弥散及吸附速率越来越慢，逐渐趋于稳态；其次利用贪婪Gauss-Seidel方法求解有机污染物在河流–地下水系统中的迁移转化机理，得出吸附体系的吸附效果随着有机物初始浓度先增加后减小，在有机污染物初始浓度为0.18 ml/L时吸附效率最好；最后采用Chapman-Enskog方法来分析了描述微观的分子运动的BGK-波尔兹曼方程与宏观的水流运动以及水流中有机污染物浓度运动之间的关系，得出随着天数增加有机污染物浓度逐渐减小，有机污染物与微生物浓度之比逐渐减小，随着微生物浓度增加，有机物浓度逐渐减小，并在第八天时趋于稳定。并且本文所探讨与研究的有机污染物在河流–地下水系统中的迁移转化机理，还将为水资源保护、利用及管理提供了强有力的工具。

Abstract: As a necessity for production and life, water resources are the most difficult to control and the most harmful in groundwater pollution, so it is of great theoretical significance and practical value to study the behavior characteristics of organic pollutants in the river-groundwater system. Firstly, the Reynolds average Navier-Stokes equation is used to establish and simulate the mathematical model of convection, dispersion and adsorption of organic pollutants in the river-groundwater sys-tem, and it is concluded that the convection, dispersion and adsorption rates of organic matter in the river-groundwater system become slower and slower with time, and gradually tend to a steady state. Secondly, the greedy Gauss-Seidel method was used to solve the migration and transfor-mation mechanism of organic pollutants in the river-groundwater system, and it was concluded that the adsorption effect of the adsorption system first increased and then decreased with the initial concentration of organic matter, and the adsorption efficiency was the best when the initial concen-tration of organic pollutants was 0.18 ml/L. Finally, the Chapman-Enskog method was used to ana-lyze the relationship between the BGK-Boltzmann equation describing the microscopic molecular motion and the macroscopic water flow movement and the organic pollutant concentration move-ment in the water flow, and it was concluded that the organic pollutant concentration gradually de-creased with the increase of days, the ratio of organic pollutants to microbial concentration gradu-ally decreased, and the organic matter concentration gradually decreased with the increase of mi-crobial concentration, and tended to stabilize on the eighth day. In addition, the migration and transformation mechanism of organic pollutants in the river-groundwater system discussed and studied in this paper will also provide a powerful tool for the protection, utilization and manage-ment of water resources.