Author:
Ren Liufen,Lin Daohui,Yang Kun
Abstract
Abstract
The debate on whether the nonlinear sorption of nonionic organic compounds (NOCs) by soil organic matter (SOM) is captured by nonlinear partition or adsorption has been going on for decades because the used SOM samples are complex mixtures from various precursors with varied humification degrees in natural environment. Therefore, in this study, hydrothermal method was employed to prepare humus-like substances from a sole precursor (i.e., rice straw) with various humification degrees for nonlinear sorption of 25 aromatic compounds, then to have an insight into the underlying mechanisms of the nonlinear sorption of NOCs by SOM. It was observed that the increasing humification degree of humus-like substances, i.e., decreasing in the polarity ((O + N)/C) and increasing in the aromaticity, result in the increase of isotherm nonlinearity and sorption capacity/affinity of NOCs. Sorption capacity of NOCs, obtained by isotherm fitting using Dubinin-Astakhov (DA) model and Dual-Mode (DM) model, are positively correlated with their solubility in water and octanol, indicating the nonlinear sorption could be captured by nonlinear partition mechanism. Specific interactions including hydrogen-bonding interaction and π-π interaction between aromatic structures of humus-like substances and organic molecules could be responsible for the nonlinear partition and the increase of sorption affinity with the enhancement of humification degree. These obtained correlations are valuable for understanding the underlying mechanisms of nonlinear sorption and elucidating the transport of NOCs in the environment.
Publisher
Springer Science and Business Media LLC
Reference46 articles.
1. Yu, H. Y.; Li, T. J.; Liu, Y. & Ma, L. M. Spatial distribution of polycyclic aromatic hydrocarbon contamination in urban soil of China. Chemosphere. 230, 498–509 (2019).
2. Alba, A. S. et al. Indentificaton of contaminants of concern in the upper tagus river basin (central Spain). Part 2: Spatio-temporal analysis and ecological risk assessment. Sci. Total. Environ. 667, 222–233 (2019).
3. Li, J. et al. Diversity of the active phenanthrene degraders in PAH-polluted soil is shaped by ryegrass rhizosphere and root exudates. Soil. Biol. Biochem. 128, 100–110 (2019).
4. Ding, Y. et al. Polycyclic aromatic hydrocarbons in agricultural soils from Northwest Fujian, Southeast China: Spatial distribution, source apportionment, and toxicity evaluation. J. Geochem. Explor. 195, 121–129 (2018).
5. Yang, K. & Xing, B. S. Soil Physicochemical and Biological Interfacial Processes Governing the Fate of Anthropogenic Organic Pollutants. In: Handbook of Soil Sciences, Second Edition, Chapter 9, Panming Huang (eds), CRC Press (2011).
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