Department of Environment Energy Engineering, Seoul National University of Science & Technology, 232 Gongneung-ro, Seoul, 01811, South Korea.
Mass Spectrometer Laboratory, National Instrumentation Center for Environmental Management, 1 Gwanak-ro, Seoul, 08826, South Korea.
Environ Res. 2022 Aug;211:113037. doi: 10.1016/j.envres.2022.113037. Epub 2022 Mar 3.
Sediment humins are extremely important for binding hydrophobic organic contaminants in rivers and lakes. Nonetheless, little is known about their structure and binding. We, therefore, examined the structure and phenanthrene sorption affinity of sediment humin samples upstream, midstream, and downstream from two artificial lakes in South Korea by using the elemental C-NMR analysis, Freundlich model, and Langmuir model. The characteristics and phenanthrene sorption affinity of sediment humins were also compared with those of sediment humic acids from similar origins as well as soil humins/humic acids in South Korea from previous studies by using principal component analysis. In both lakes, downstream sediment humins exhibited lower N/C, O/C, and (N + O)/C ratios, lower internal oxidation, and higher aliphaticity due to the presence of long-chain aliphatic compounds generated during anaerobic decomposition. The principal component analysis results also showed that C,H-alkyl, O-alkyl, and polar organic carbon contents were significantly different when comparing the up-mid stream and downstream sediment samples in Daecheong Lake. In addition, midstream sediment humin in Andong Lake presented higher C,H-alkyl and lower polar organic carbon contents compared to those of up-downstream samples. In both lakes, the sorption coefficient and adsorption isotherm linearity were positively correlated with the C,H-alkyl content and negatively correlated with the O-aryl content. Similar to C,H-alkyl and POC, C,H-alkyl, and (N + O)/C had an extremely high correlation coefficient when predicting the sorption coefficient (Freundlich model) and the maximum adsorption capacity (Langmuir model) of sediment humins. Sediment humins had higher C,H-alkyl contents and lower sorption coefficients than those of sediment humic acids and soil humins/humic acids. These findings provide key information for monitoring water quality and polycyclic aromatic hydrocarbon contamination in South Korean lake sediments.
沉积物腐殖质对于结合河流和湖泊中的疏水性有机污染物非常重要。尽管如此，人们对其结构和结合方式知之甚少。因此，我们使用元素 C-NMR 分析、Freundlich 模型和 Langmuir 模型，研究了韩国两个人工湖中上游、中游和下游沉积物腐殖质样品的结构和菲的吸附亲和力。还通过主成分分析，将沉积物腐殖质与类似来源的沉积物腐殖酸以及韩国先前研究中的土壤腐殖质/腐殖酸的特性和菲吸附亲和力进行了比较。在两个湖泊中，由于厌氧分解过程中产生的长链脂肪化合物的存在，下游沉积物腐殖质表现出较低的 N/C、O/C 和 (N+O)/C 比、较低的内部氧化程度和较高的脂肪性。主成分分析结果还表明，在比较大青湖的上中游和下游沉积物样品时，C,H-烷基、O-烷基和极性有机碳含量存在显著差异。此外，与上下游样品相比，安洞湖的中游沉积物腐殖质具有较高的 C,H-烷基和较低的极性有机碳含量。在两个湖泊中，吸附系数和吸附等温线线性与 C,H-烷基含量呈正相关，与 O-芳基含量呈负相关。与 C,H-烷基和 POC 相似，C,H-烷基和 (N+O)/C 与沉积物腐殖质的吸附系数（Freundlich 模型）和最大吸附容量（Langmuir 模型）的相关性极高。与沉积物腐殖酸和土壤腐殖质/腐殖酸相比，沉积物腐殖质具有更高的 C,H-烷基含量和更低的吸附系数。这些发现为监测韩国湖泊沉积物的水质和多环芳烃污染提供了重要信息。
