Birnessite-Induced Binding of Phenolic Monomers to Soil Humic Substances and Nature of the Bound Residues

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• 作者：Chengliang Li ; Bin Zhang ; Tanya Ertunc ; Andreas Schaeffer ; Rong Ji
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：August 21, 2012
• 年：2012
• 卷：46
• 期：16
• 页码：8843-8850
• 全文大小：382K
• 年卷期：v.46,no.16(August 21, 2012)
• ISSN：1520-5851

文摘

The nature of the abiotic birnessite (未-MnO₂)-catalyzed transformation products of phenolic compounds in the presence of soil organic matter is crucial for understanding the fate and stability of ubiquitous phenolic carbon in the environment. ¹⁴C-radioactive and ¹³C-stable-isotope tracers were used to study the mineralization and transformation by 未-MnO₂ of two typical humus and lignin phenolic monomers鈥昪atechol and p-coumaric acid鈥昳n the presence and absence of agricultural and forest soil humic acids (HAs) at pH 5鈥?. Mineralization decreased with increasing solution pH, and catechol was markedly more mineralized than p-coumaric acid. In the presence of HAs, the mineralization was strongly reduced, and considerable amounts of phenolic residues were bound to the HAs, independent of the solution pH. The HA-bound residues were homogeneously distributed within the humic molecules, and most still contained the unchanged aromatic ring as revealed by ¹³C NMR analysis, indicating that the residues were probably bound via ester or ether bonds. The study provides important information on 未-MnO₂ stimulation of phenolic carbon binding to humic substances and the molecular distribution and chemical structure of the bound residues, which is essential for understanding the environmental fates of both naturally occurring and anthropogenic phenolic compounds.