固体废物处理厂地下水污染预测及控制模拟

[目的]以江苏省镇江市新区大港片区某固体废物处理厂为研究对象,对地下水污染情况进行模拟研究,为同类建设项目及企业的地下水污染预测和防治提供参考。[方法]通过系统分析该固体废物处理厂野外水位和水质观测数据以及水文地质条件等资料,利用Visual Modflow软件构建了地下水水流和溶质运移模型。[结果]对厂区污水处理站防渗破损后特征污染物CODMn和氨氮运移情况以及地表硬化污染控制措施对污染物的阻隔效果进行预测评价,数值模拟预测污染物的影响范围、超标范围和最大运移距离。预测时间20a后,污染物影响范围最大,运移距离最远,且CODMn影响范围较氨氮大,运移距离较远;地表硬化后,20a后污染羽未超出评价范围。[结论]污染物主要沿水流方向迁移,对水环境的影响随时间逐渐增大,污染物浓度随着迁移距离的增加而减小,不同污染物在地下水含水层中的溶质运移范围和迁移距离不同。地表硬化措施能有效控制污染物扩散。

Simulation on Contamination Forecast and Control of Groundwater in a Solid Waste Treatment Plant

[Objective] Taking a solid waste treatment plant in Dagang Area of Zhenjiang New Area in Jiangsu Province as the research object, the groundwater pollution was simulated to provide a reference for the prediction and control of groundwater pollution of similar construction projects and enterprises.[Methods] By systematically analyzing field water level, water quality observation data and hydrogeological conditions of the solid waste treatment plant, the groundwater flow and solute transport model were established by Visual Modflow software.[Results] We simulated the migrations of COD_Mn and NH₃-N characteristic pollutants after seepage damage of the factory sewage treatment station, predicted the barrier effect of surface hardening pollution control measures on pollutants, and predicted the pollutant influenced range, over standard range and maximal migration distance by numerical simulation. It was predicted that after 20 years, the pollutant would have the largest influence range and the farthest migration distance, and the influence range of COD_Mn would be larger than that of NH₃-N, and the migration distance be more than that of NH₃-N. After the surface hardening, the pollution feather would not exceed the scope of this assessment.[Conclusion] The pollutants mainly migrate in the direction of water flow, the impact on water environment increases with time, the pollutant concentration decreases with the increase of migration distance. Different contaminants have different solute transport ranges and migration distances in groundwater aquifers. And surface hardening measures can effectively control the spread of pollutants.