New methods to measure and predict fate of chemicals in soil

本研究的目的是获得一个更好的理解，并能够更好地预测环境化学品在城市或农业土壤system.We的吸附，运输和命运已经表明，小的土壤颗粒（胶体）吸附相对更多的化学品（农药）比散装土壤，从而给胶体促进化学浸出的风险增加。这两种化学品表现出明显的吸附-解吸非奇异性（吸附滞后），因此在土壤修复和清理过程中有被固定在土壤中的趋势。此外，我们还开发和测试了一种新的，快速的方法（[HPLC]微柱法），用于直接测量溶解有机化学品在土壤中的迁移和吸附在自然水流条件下，我们描述了蒸汽吸附如何与土壤-空气湿度和土壤-水含量，土壤比表面积和土壤质地。这些研究涉及挥发性农药（二嗪农）和其他经常使用的有毒农药， ...更多信息 挥发性有机化合物（苯、甲苯和三氯乙烯）。我们进一步使用我们的气相色谱[GC]微柱法直接测量VOC在非饱和土壤中的迁移，并分析了相应的条件下，土壤蒸汽提取基于污染土壤场地的清理的结果。结果表明，蒸汽吸附空气和水的渗透性和气体扩散率可以显着影响清理时间。我们已经开发了一个孔隙尺寸依赖模型的空气和气体渗透性在原状土。我们已经开发了新的，更准确的模型，在原状土壤中的饱和和非饱和导水率，作为土壤水分含量和孔径分布的函数。我们已经开发了第一个现实的气体扩散系数在原状土壤中的空气渗透率，孔径分布，和土壤宏观孔隙度的模型。所有的新模型进行了测试，对日本，欧洲和美国的土壤数据，并显示出比以前现有的模型更准确。少

The objective of this research is to obtain a better understanding and better be able to predict sorption, transport and fate of environmental chemicals in urban or agricultural soil systems.We have shown that small soil particles (colloids) adsorbed relative more chemical (pesticide) than the bulk soil, thus giving an increased risk of colloid-facilitated chemical leaching. Both chemicals showed pronounced adsorption-desorption non-singularity (sorption hysteresis) and thus has a tendency to be immobilized in the soil during soil remediation and clean-up. Also, we have developed and tested a new, rapid method ( [HPLC] Micro-column Method) for direct measurement of dissolved organic chemical transport and sorption in soil during natural water flow conditions.We have described how the vapor sorption relates to soil-air humidity and soil-water content to soil specific surface area and soil texture. The studies concerns both volatile pesticides (diazinon) and other frequently used toxic v … More olatile organic compounds (benzene, toluene, and trichloroethylene). We have further used our Gas Chromatography [GC] Micro-column Method for direct measurement of VOC transport in unsaturated soil and analyzed the results under conditions corresponding to soil vapor extraction based clean-up of a polluted soil site. It was shown that both vapor sorption air and water permeability and gas diffusivity can significantly affect clean-up time.We have developed a pore-size dependent model for air and gas permeability in undisturbed soil. We have developed new, more accurate models for saturated and unsaturated hydraulic conductivity in undisturbed soils, as functions of soil-water content and pore-size distribution. We have developed the first realistic models for gas diffusion coefficients in undisturbed soil as related to air permeability, pore-size distribution, and soil macro-porosity. All the new models were tested against the data for Japanese, European and American soils and showed to be more accurate than previously existing models. Less