纳米碳对扰动黄绵土水分入渗过程的影响

将纳米材料应用于土壤物理学领域对减少土壤水分流失、提高土壤水肥利用效率、优化土壤物理结构有着重要的意义。基于扰动黄绵土土柱室内一维入渗试验,研究了纳米碳含量(质量含量分别为0、0.001、0.005、0.007、0.010 g g-1)对扰动黄绵土的水分入渗过程及饱和导水率的影响。结果表明:(1)纳米碳对扰动黄绵土水分入渗有显著影响。一定入渗历时内,随着纳米碳含量增大,累积入渗量及湿润锋推进速率均呈显著减小趋势。(2)Kostiakov公式和Philip方程均能较好地描述添加纳米碳的扰动黄绵土累积入渗量随时间的变化过程。其中,Kostiakov公式拟合精度更高。(3)湿润锋随时间变化符合幂函数关系。(4)纳米碳对扰动黄绵土的饱和质量含水量和饱和导水率影响同样显著。随纳米碳含量增加,前者增大,后者减小,与纳米碳含量变化分别符合二项式和指数函数关系。

Effects of nano-carbon on water infiltration process in disturbed loessal soil

Application of nano-materials to soil physics is a new breakthrough in the field, and its effects are significant in reducing soil water loss and improving soil water and fertilizer utilization efficiency and soil physical structure. A one-dimensional water infiltration experiment was carried out in disturbed loessal soil columns in laboratory for analysis of effects of content of nano-carbon (0 g g-1, 0.001 g g-1, 0.005 g g-1, 0.007 g g-1 and 0.01g g-1) on soil water infiltration process and saturated hydraulic conductivity. Results show that (1) the influence of nano-carbon on water infiltration in the disturbed loessal soil was significant, and within a certain infiltration time period, cumulative infiltration and wetting front moving rate tended to decrease with the increasing content of nano-carbon; (2) Kostiakov formula and Philip equation could both be used to describe how cumulative water infiltration varied with time in the disturbed loessal soil treated with nano-carbon and the former fitted better; (3) variation of the wetting front with time demonstrated a power function relationship; and (4) nano-carbon also affected significantly saturated mass water content and saturated hydraulic conductivity in the disturbed loessal soil, and with the increasing content of nano-carbon, the former tended to increase,while the later decrease, which fitted well the binomial expression and exponential function, respectively. Key words Nano-carbon; Cumulative infiltration; Wetting front; Saturated mass water content; Saturated hydraulic conductivity