Abstract：
Understanding the influence of soil microstructure on light non-aqueous phase liquids (LNAPLs) behavior is critical for predicting the formation of residual LNAPLs under spill condition. However, the roles of soil particle and pore on LNAPLs migration and residue remains unclear. Here, the experiment simulated an LNAPLs (diesel) spill that was performed in fourteen types of soils, and the key factors affecting diesel behavior are revealed. There were significant differences between fourteen types of soils, with regard to the soil particle, soil pore, and diesel migration and residue. After 72 h of leakage, the migration distance of diesel ranged from 3.42 cm to 8.82 cm in the soils. Except for sandy soil, diesel was mainly distributed in the 0−3 cm soil layer, and the residual amounts were 7.85−26.66 g/kg. It was further confirmed from microstructure that the consistency of soil particle and volume of soil macropores (0.05−7.5 μm) are important for diesel residue in the 0−1 cm soil layer and migration distance. The large soil particles corresponding to 90% of volume fraction and volume of soil mesopores (<0.05 μm) are key factors affecting diesel residue in the 1−3 cm soil layer. The result helps to further comprehend the formation mechanism of residual LNAPLs in the soil.
摘要：
了解土壤微观结构对轻质非水相液体（LNAPL）行为的影响对于预测泄漏条件下残留LNAPL的形成至关重要。然而,土壤颗粒和孔隙对LNAPLs迁移和残留的作用尚不清楚。这里,实验模拟了在14种土壤中进行的LNAPL(柴油)泄漏，并揭示了影响柴油行为的关键因素。14种土壤类型之间存在显著差异，关于土壤颗粒，土壤孔隙,以及柴油迁移和残留。泄漏72小时后，柴油在土壤中的迁移距离为3.42cm至8.82cm。除了沙质土壤,柴油主要分布在0-3厘米的土层，残留量为7.85-26.66g/kg。从微观结构进一步证实，土壤颗粒的稠度和土壤大孔隙的体积（0.05-7.5μm）对于0-1cm土层中的柴油残留和迁移距离很重要。土壤中孔体积分数和体积的90％（<0.05μm）对应的大颗粒是影响1-3cm土层柴油残留的关键因素。研究结果有助于进一步理解土壤中残留LNAPLs的形成机理。
