Colloid facilitated contaminant transport in soil.

胶体促进污染物在土壤中的迁移。

• 批准号: 11650562
• 负责人: KOMATSU Toshiko
• 金额: $ 2.3万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650562/
• 关键词: Soil colloid; Soil and groundwater pollution; Undisturbed soil; macropore; Pesticide adsorption; Parabolic diffusion model; Colloid Mobilization Index; Phosphorus leaching; 汚染物質輸送; 不攪乱土壌; Macropore; 土層厚; リンの流出

Until recently, it was believed that the tranport of chemicals to the groundwater would happen mainly in the form of chemicals dissolved in the soil-water. However, recent studies indicate that small inorganic and organic particles in the soil are relatively mobile and can be transported with the infiltrating water. These colloidal particles have a large surface area per gram of dry particles (typically in the order of 100-1000 m^2/g). In theory, the colloids may therefore be able to carry significant amounts of sorbing chemicals with them through the soil.The purpose of this research is to investigate the effcet of three factors, colloid-chemical interactions, colloid mobility, and soil structure on colloid-facillitated transport of chemicals.Concerning colloid-chemical interactions, we have shown that the small particle size fractions of the soil with high soil surface area have higher capacity to adsorb chemicals and that the colloidal-chemical reactions are strongly time-dependent. Also we found that when both a strongly-sorbing pesticide (glyphosate) and phosphorus are present in the soil, these two chemicals will compete for the total sorption capacity.Concerning colloid mobility and soil structure, a large measurement program on a loamy soil from Hiroshima prefecture showed the effect of several factors on colloid mobility during intermittent rainfall events. Large effects of both irrigation water composition and of soil structure (undisturbed or repacked soils and also soil with or without continuous macropores) were obseved. We found that accumulated colloid leaching from soils containing continuous macropores could be described by a parabolic diffusion type model. Also we developed models that can describe diffusion-controlled colloid transport through structured soils and that agree well with our measured data.

直到最近，人们还认为化学物质进入地下水的主要形式是溶解在土壤水中的化学物质。然而，近年来的研究表明，土壤中的无机和有机小颗粒具有相对的流动性，可以随着入渗水的迁移而迁移。这些胶体颗粒每克干燥颗粒具有很大的表面积（通常在100-1000 m^2/g的数量级）。理论上，胶体可能因此能够携带大量的吸收化学物质通过土壤。本研究的目的是探讨三个因素，胶体-化学相互作用，胶体流动性和土壤结构对胶体促进化学物质运输的影响。关于胶体-化学相互作用，我们已经表明，具有高土壤表面积的土壤的小粒度组分具有更高的吸附化学物质的能力，并且胶体-化学反应具有强烈的时间依赖性。我们还发现，当土壤中同时存在强吸附农药（草甘膦）和磷时，这两种化学物质将竞争总吸附能力。在胶体流动性和土壤结构方面，通过对广岛县壤土的大规模测量，揭示了间歇性降雨过程中多种因素对胶体流动性的影响。灌溉水组成和土壤结构（未扰动或重新填充的土壤以及有或没有连续大孔隙的土壤）都有很大的影响。研究发现，含连续大孔隙的土壤中胶体的累积淋滤可以用抛物扩散型模型来描述。此外，我们还开发了可以描述扩散控制的胶体在结构性土壤中的运移的模型，该模型与我们的测量数据吻合得很好。

项目成果

de Jonge,H.: "Glyphosate sorption in soils of different pH and Phosphorus content"Soil Science. (in press). (2001)

de Jonge, H.：“不同 pH 值和磷含量的土壤中草甘膦的吸附”土壤科学。

Schelde,K.: "Diffusion-limited mobilization and transport of natural colloids in macroporous soils"AGU Water Resources Research. (in press). (2001)

Schelde,K.：“大孔土壤中天然胶体的扩散限制动员和运输”AGU 水资源研究。

本下晶晴: "ダムサイト緑化試験区からのリンの流出におけるコロイド粒子の関与"環境工学研究フォーラム講演集. 37. 61-63 (2000)

本下秋晴：“坝址绿化试验区磷流出中胶体颗粒的参与”环境工程研究论坛讲座。 37. 61-63 (2000)

Motoshita, M.: "Contribution of soil colloid particles to phosphorus leaching from dam site green belts."Environmental Engineering Research Forum (short communication). 37. 61-63 (2000)

Motoshita, M.：“土壤胶体颗粒对坝址绿化带磷浸出的贡献。”环境工程研究论坛（短交流）。

Motoshita, M.: "Soil colloid mobilization and transport in intact and repacked soil columns during periods of irrigation"Journal of Japan Society of Civil Engineering (JSCE). (in press). (2001)

Motoshita, M.：“灌溉期间完整和重新填充的土壤柱中的土壤胶体动员和运输”日本土木工程学会 (JSCE) 杂志。