Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
Environ Sci Technol. 2011 Mar 15;45(6):2124-30. doi: 10.1021/es102468z. Epub 2011 Feb 22.
The sorption behavior of organic compounds (phenanthrene, lindane, and atrazine) to sequentially extracted humic acids and humin from a peat soil was examined. The elemental composition, XPS and (13)C NMR data of sorbents combined with sorption isotherm data of the tested compounds show that nonspecific interactions govern sorption of phenanthrene and lindane by humic substances. Their sorption is dependent on surface and bulk alkyl carbon contents of the sorbents, rather than aromatic carbon. Sorption of atrazine by these sorbents, however, is regulated by polar interactions (e.g., hydrogen bonding). Carboxylic and phenolic moieties are key components for H-bonding formation. Thermal analysis reveals that sorption of apolar (i.e., phenanthrene and lindane) and polar (i.e., atrazine) compounds by humic substances exhibit dissimilar relationships with condensation and thermal stability of sorption domains, emphasizing the major influence of domain spatial arrangement on sorption of organic compounds with distinct polarity. Results of pH-dependent sorption indicate that reduction in sorption of atrazine by the tested sorbents is more evident than phenanthrene with increasing pH, supporting the dependence of organic compound sorption on its polarity and structure. This study highlights the different interaction mechanisms of apolar and polar organic compounds with humic substances.
研究了有机化合物（菲、林丹和莠去津）对泥炭土壤中顺序提取的腐殖酸和腐殖质的吸附行为。吸附剂的元素组成、XPS 和（13）C NMR 数据以及测试化合物的吸附等温线数据表明，非特异性相互作用控制着腐殖质对菲和林丹的吸附。它们的吸附取决于吸附剂的表面和体烷基碳含量，而不是芳香碳。然而，这些吸附剂对莠去津的吸附受极性相互作用（如氢键）的调节。羧酸和酚基部分是氢键形成的关键组成部分。热分析表明，腐殖质对非极性（即菲和林丹）和极性（即莠去津）化合物的吸附与吸附域的缩合和热稳定性之间呈不同的关系，这强调了域空间排列对具有不同极性的有机化合物吸附的主要影响。pH 值依赖性吸附的结果表明，随着 pH 值的增加，测试吸附剂对莠去津的吸附减少更为明显，这支持了有机化合物吸附与其极性和结构的依赖性。本研究强调了非极性和极性有机化合物与腐殖质之间不同的相互作用机制。
