Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants that widely distribute in the environment.The biodegradation half-life times (t1/2) of PAHs is a key activity parameter for describing the persistency of PAHs in environmental phases.Quantum chemical parameters computed using density functional theory (DFT) methods at the B3LYP/6-31G(d) level,and stepwise multiple linear regression (MLR) analysis with an optimized procedure were used to generate quantitative structure-activity relationship (QSAR) models for lg t1/2 of 11 PAHs.The correlation coefficient of the optimal model was 0.960,moreover,the results of the test and external test showed that this optimal model display a high fitting precision and good prediction.The lg t1/2 values predicted by the optimal model are very close to those observed in experiments.The MLR analysis also indicated that PAHs in soils with larger electronic spatial extent (Re) tend to more readily biodegraded by microorganism.%多环芳烃(PAHs)是一类在环境中广泛分布的持久性有机污染物,其微生物降解半衰期t1/2是描述PAHs的微生物降解性能的一个关键参数,对于评估PAHs在环境中的持久性具有重要意义.在B3 LYP/6-31G (d)理论水平下对11种PAHs分子进行量子化学计算并提取量子化学参数,运用逐步多元线性回归分析建立了PAHs量子化学参数与土壤中PAHs微生物降解半衰期的定量预测模型.该模型的相关系数的二次方达到0.960,并且内部检验和外部检验结果都显示所获得的模型具有较高的拟合精度和较好的预测稳定性,可有效评估PAHs在土壤中的分配能力.模型变量重要性分析表明电子空间广度对PAHs在土壤中的持久性起着关键作用,具有较大Re值的PAHs分子在土壤中更容易被微生物降解.
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