污染河水对地下水化学环境的影响

The Impact of Polluted River Upon Groundwater Chemical Environment

地表浅部岩土层对水中有机物、悬浮物、胶体等杂质的过滤截留作用是显著的 ,具有随岩土颗粒由粗到细 ,对杂质的去除率逐渐增强的特点。污水补给地下水后 ,地下水化学环境在距河流一段距离先呈厌氧环境 ,其NH+4稳定 ,SO2 -4 减少 ,HCO-3 升高 ,随后逐渐向喜氧环境转化 ,导致NH+4 降低 ,NO-3 和NO-2 增加 ,HCO-3 减少 ,SO2 -4骤然增多 ,即出现强烈的硫化及硝化作用。厌氧环境沿河道在补给地下水方向呈条带状分布 ,其宽度受水力坡度、岩土颗粒大小。

The organic material, suspension material and colloid can be filtered when water permeats through the surface soil. The efficiency of filter depends on the size of soil particles. The smaller the size of particles, the higher the efficiency of removing impurity. The environment of groundwater is anaerobic as supplied by polluted river water. The concentration of NH + 4 is very stable, SO 2- 4 reduces,and HCO - 3 increases. An anaerobic environment exits in the shape of belt along the river. The width of the ribbon is affected by the slope of hydraulic-power,the size of particles,the concentration of wastewater and time.