Risk Assessment on Groudwater Contamination Accompanying with Soil Adsorption

主要研究内容如下：(1)土壤颗粒、孔结构和吸附容量。(2)各污染物的吸附特性；(3)环境风险评价的质量控制。活动一得出结论：(1)土壤对土壤的吸附与含水饱和度无关，但分散性随含水饱和度的降低而增加。(2)提出了一种利用透气性试验估算砂土孔隙大小的新方法，第二种方法的结果是：(1)随着其他共存组分浓度的增加，溶质组分的分配系数变小；(2)竞争吸附模拟表明，由于少量污染物的吸附，背景组分的吸附特性没有发生变化，但背景组分吸附后，少量污染物的吸附减少了。模拟结果表明，与土壤吸附和生物反应有关的参数对环境风险评价中肥料的运移有重要影响。

Research projects were accomplishied according to the following studies ; (1) Soil Particle, Pore Structure and Adsorption Capacity. (2) Adsorption Characteristics of Each Contaminants, and (3) Quality control for Environmental Risk Assessment.The first activity gave the conclusions ; (1) Soil adsorption took a constant value independent on water saturation, on the other hand, dispersibility increased with decreasing water saturation. (2) A new method was proposed to estimate the pore size of sand using an air permeability test with air injection.The results of the second activity were that ; (1) Distribution coefficient for a solute components took a small value with increasing the concentration of the other coexisting components, and (2) Modeling of competitive adsorption indicates that no change took place in adsorption characteristics of background components due to a small amount of contaminants adsorption, however, a small amount of contaminants adsorption decreased after background components adsorption.The third was performed by water quantity estimation of tank model and water quality of soil compartment model. The simulation results showed that the parameter relating to soil adsorption and biological reaction play an important role on transport of fertilizer for the environmental risk assessment.