ENVIRONMENTAL PREDICTION FOR MUNICIPAL RIVER WASTEWATER INFILTRATION ON GROUNDWATER POLLUTION AND ITS APPLICATION

摘要

The quality characteristics and pollution degree of groundwater directly represent its environment quality. The discharge of municipal wastewater leads to the groundwater quality seriously polluted. The interrelation between the pollution of Xihe River and offshore groundwater are analyzed based on inspecting water quality results. Some groundwater chemical indices exceed the national drinking water quality standards. Taking Chromium (Ⅵ) as an example, a coupled dynamic model forecasting the impacts of rive wastewater infiltration on its offshore soil and groundwater pollution has been developed based on the infiltration process and the transportation and transformation process of groundwater contaminants in vadose zone and aquifers in the region of Xihe River are analyzed. Numerical results show that unsaturated soil properties has a large impact on wastewater leakage on groundwater pollution, and the pollution range of municipal wastewater to groundwater is presented. One-dimensional column experiment of wastewater containing Chromium (Ⅵ) is conducted in the laboratory. Experiment results presented that soil texture has a direct connection with soil leaching height, also exerting an influence on leaching concentration. The maximum leaching depth is 60 cm in clay soil, whereas for 30 cm in sand soil. It indicates reasonable agreement between model simulation and measured data. It provides theoretical evidence for quantitative assessment of potential effects of contaminant in municipal wastewater on groundwater pollution, and the science evidence are provided for government agencies for regulatory purpose and planners for making management decision.