| Portable soil colloid is one more active ingredient in underground water, which can facilitate the pollutant's migration. The migration rule can provide theoretical basis and technical support for the risk assessment and repair of contaminated sites. In this study, colloids samples were extracted from three kinds of typical soil in China ?black soil, moisture soil and red soil? and characterized including physical and chemical properties qualitatively and quantitatively. Through leaching experiments in the soil column, the transportation characteristics and the migration rule of the colloid were studied under the influence of different pH and ionic strength ?IS? condition, and its effect on enanthrene in soil column was also researched.The results showed that more than 90% extracted colloidal particle sizes were less than 1?m. The mineral type and content of three kinds of colloids were different. The species of chemical groups in different colloids are similar but the quantity was different. The pH and ionic strength of eluent had a more significant impact on colloid transport in soils. Take the black soil colloid as example, when the pH was increased from 4 to 9, k value was correspondingly reduced from 6.020× 10-4 to 3.858×10-4. When Ca2+, K+, Na+ ionic strength were changed from 0.5mM to 0.001mM, k values were reduced from 6.087×10-4,3.818×10-4 from 5.518× 10-4, and 4.109×10-4 from 5.401 ×10-4 to 4.024×10-4 respectively. The influence of pH and IS had the same effect trend on different types of colloid, but different on the degree. The order of pH influence on soil colloid transport was as below:black soil> red soil> moisture soil. The order of IS influence on soil colloid transport was as below: red soil> black soil> red soil. Three kinds of soil colloid on phenanthrene migration in soil column has effect, but the facilitation extent was different, the order was as below: moisture soil> red soil> black soil. |
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