土壤湿度对土壤中对硝基氯苯提取率的影响

在"固–气–液"三相体系中,通过土壤加标污染物并控制湿度的实验,研究了土壤湿度对p-NCB在土壤及其成分中提取率的影响。结果表明:土壤湿度造成p-NCB在两种土样上的提取率较干燥土样显著减小。土壤成分实验中,高岭石中p-NCB的提取率受样品湿度的影响较大,腐殖酸的存在大大减小了土壤湿度对高岭石中p-NCB老化过程的影响。土壤湿样中p-NCB提取率在反应21天后开始变缓,说明p-NCB在土壤湿样上的老化过程分可为两个阶段:自反应开始至进行到第21天是快速老化阶段,之后为缓慢老化阶段。p-NCB在土壤干样上的老化过程不明显,在实验周期下未发现提取率随反应时间有明显下降。

Effect of Soil Moisture on Extraction Rate of p-NCB in Soil

In the "solid-gas-liquid" system, the effects of soil moisture on the extractability of p-NCB in two soils and soil components (e.g. Gaolinite, Humic acids and their complex) were studied to explore the inner mechanisms. The effect of soil moisture on the extractability of p-NCB was conducted by spiking and subsequent moisture control of the soil samples. The results showed that soil moisture decreased the extractability of p-NCB on soils considerably. In the soil constituents-simulation experiments, the effect of sample moisture on the extractability of p-NCB in gaolinite was the maximum. Humic acids eliminated the effect of sample moisture on the extractability. The extractability decreased little after 21 days reaction suggested that aging of p-NCB on soils could be divided into two stage: from the beginning to less than 21 days was the fast aging stage, and after that was the stabilization stage. The extractability of p-NCB on the dry samples was almost unchanged after 120 days experiment, suggesting aging of p-NCB was not obvious on the dry soil samples.