Crude oil may block soil pores, affect soil water repellency, and change soil water movement. In this study, soil column simulation was used to study the effects of different crude oil pollution levels (0, 0.5%, 1%, 2%, 4%) on the water infiltration processes in loessial soil and aeolian sandy soil. The results showed that soil wetting front speed and infiltration rate of those two soils decreased with increasing crude oil content. The time needed for wetting front reaching the bottom of the soil column was the longest under 4% crude oil polluted soil, which was 4 times and 48 times longer than that of no crude oil polluted soil for loessial soil and aeolian sandy soil, respectively. The cumulative infiltration of loessial soil decreased with increasing crude oil content, while it increased to the max and then decreased as the crude oil content increased in aeolian sandy soil. The cumulative infiltration curves of aeolian sandy soil with high crude oil contents (2% and 4%) presented "up-tail" phenomenon. Kostiakov infiltration model and Philip infiltration model could better fit the infiltration process than Green-Ampt model for loessial soil with different crude oil content. However, the two models could only well fit the infiltration process for aeolian sandy soil with low crude oil content (0, 0.5%, 1%). Crude oil pollution could significantly affect soil water infiltration process, especiall in aeolian sandy soil.
原油进入土壤后会堵塞土壤孔隙,影响土壤斥水性,改变土壤水分运动状况。本研究利用土柱模拟的方法,研究了不同原油污染程度(0、0.5%、1%、2%、4%)对黄绵土和风沙土水分入渗过程的影响。结果表明: 随着原油含量的增加,两种土壤湿润锋的推进速度和入渗速率均减小,土壤原油污染程度为4%时湿润锋运移到土柱底部的所需时间最长,污染程度为0时湿润锋运移到土柱底部的所需时间最短,黄绵土湿润锋达到土柱底部所需最长时间是最短时间的5倍,风沙土最长时间是最短时间的48倍;当湿润锋运移到土柱底部时,黄绵土的累积入渗量随原油含量的增加而减小,而风沙土的累积入渗量先增大后减小;在高浓度(2%、4%)原油处理下,风沙土的累积入渗量曲线出现“翘尾”现象。Kostiakov入渗模型和Philip入渗模型比Green-Ampt模型能更好地模拟不同原油处理下的黄绵土土壤水分入渗过程,但对风沙土而言,两种模型对低浓度(0、0.5%、1%)原油处理的土壤水分入渗过程拟合较好。原油污染能够显著影响土壤水分入渗过程,且对风沙土的影响更大。.
Keywords: model simulation; oil; soil texture; soil water infiltration.