菲(C14H10)在东北黑土中的吸附及冷冻-消融对其可提取性影响

Adsorption of Phenanthrene in Black Soil and Effect of Freeze-thawing Cycles on Its Extraction

疏水性有机物进入土壤后,随着与土壤的接触时间延长,发生老化现象,导致其可提取性和生物可利用性下降。以菲为目标污染物,考察了其在黑土原土及三种不同粒组土样上的吸附行为,并采用加标法考察了不同的冷冻-消融周期对菲的可浸提性影响。研究结果表明：菲在黑土及不同粒组土样的吸附等温线可用Freundlich方程较好地拟合（R2≥0.953 0）,1/n值为0.769 5~1.083 6。冷冻-消融处理可显著降低菲在黑土及不同粒组土样中的可浸提率,且经第1次冷冻-消融老化后的可浸提率降低最多。因此,在评价有机污染物的环境风险时应充分考虑其在土壤中的老化作用。

When the Hydrophobic organic compounds leak into the soil, with the contact time increase between the hydrophobic organic compounds and the soil, it can lead to the extraction rate and the bioavailability decrease. We used phenanthrene as target pollutant to study the adsorption behavior of phenanthrene in original black soil and three different fractions soil. The effect of different freeze- thawing cycles on its extraction was also studied by using standard addition method. The results shown that the adsorption isotherm fit Freundlich equation well （R2 ≥0. 953 0） and 1/n was in the range of 0. 7695 ~ 1. 083 6. The extraction of phenanthrene in black soil and its different fractions can be significantly reduced by freeze-thaw treatment, and the extraction rate decreased the most after the first time of freeze-thawing cycles. So, the aging effect should be considered to evaluate the environmental risks of organic pollutants in soil.