Quantitative structure-activity relationships for evaluating the influence of sorbate structure on sorption of organic compounds by soil
Quantitative structure-activity relationships for evaluating the influence of sorbate structure on sorption of organic compounds by soil
复制标题
用于评估山梨酸盐结构对土壤吸附有机化合物影响的定量构效关系
DOI：
10.1002/etc.5620140703
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发表时间：
1995
影响因子：
4.1
通讯作者：
M. Brusseau
中科院分区：
文献类型：
--
作者：
Q. Hu;Xiaojiang Wang;M. Brusseau
采用定量构效关系(QSAR)方法，研究了不同有机质含量的两种土壤对有机化合物吸附的影响。对代表六类非极性、非电离有机化学品的几种有机污染物进行了混相置换实验，这些有机污染物包括氯化脂肪烃、氯苯、多环芳烃(PAHs)、正烷基苯、甲基苯和多氯联苯(PCbs)。用双连续模型分析了穿透曲线，该模型假定对一部分吸附剂的吸附是瞬时的，而对其余的吸附剂是速率受限的。采用定量构效关系方法研究了平衡和非平衡吸附系数与代表溶质结构性质的拓扑参数之间的关系。对于平衡参数和非平衡参数，一阶价分子连接性(1XV)是最好的拓扑描述参数。大多数限速吸附行为可以用溶质分子的大小和结构来解释，如速率系数和1XV之间的良好相关性所表明的那样。这支持了这样一种观点，即这些体系中的限速吸附是由物理扩散机制控制的，这与聚合物扩散模型一致。在此模型的基础上，计算了波登山和山顶的扩散长度比。柠檬土壤在有机质含量上有很大的差异，与从测量的速率数据确定的值相比是有利的。
The purpose of this work was to investigate the effect of sorbate structure, by using the quantitative structure-activity relationship (QSAR) approach, on sorption of organic compounds by two soils with different amounts of organic matter. Miscible displacement experiments were performed with several organic contaminants representing six classes of nonpolar, nonionizable organic chemicals, including chlorinated aliphatics, chlorobenzenes, polycyclic aromatic hydrocarbons (PAHs), n-alkylbenzenes, methylated benzenes, and polychlorinated biphenyls (PCBs). The breakthrough curves were analyzed by using a bicontinuum model wherein sorption is assumed to be instantaneous for a fraction of the sorbent and rate limited for the remainder. The QSAR approach was used to investigate the dependency of both equilibrium and nonequilibrium sorption coefficients on topological descriptors representing structural properties of the solutes. For both equilibrium and nonequilibrium parameters, the first-order valence molecular connectivity (1Xv) was found to be the best topological descriptor. Most of the rate-limited sorption behavior could be explained by accounting for the size and structure of the solute molecule, as indicated by the good correlation between the rate coefficient and 1Xv. This supports the contention that rate-limited sorption in these systems is controlled by a physical diffusion mechanism, consistent with the polymer diffusion model. Based on this model, the calculated diffusion-length ratios for the Borden and Mt. Lemmon soils, which have a large difference in organic-matter contents, compare favorably to the values determined from the measured rate data.