In situ investigation of intrinsic relationship between protonation behavior and HA characteristics in sediments
| Autor: | Zhongwu Li, Ninglin Luo, Xiang Ding, Ming Chen, Mei Huang, Jiajun Wen, Wenle Xing, Weihua Xu, Ren Yang |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
In situ Environmental Engineering 010504 meteorology & atmospheric sciences Proton binding Chemistry Inorganic chemistry Sediment Protonation 010501 environmental sciences 01 natural sciences Pollution Environmental Chemistry Humic acid Titration Binding site Waste Management and Disposal Two-dimensional nuclear magnetic resonance spectroscopy 0105 earth and related environmental sciences |
| Zdroj: | Science of The Total Environment. 683:258-266 |
| ISSN: | 0048-9697 |
| Popis: | Proton-binding study of humic acid (HA) is critical for describing and modeling the binding mechanism of HA with heavy metals. However, little is known about the intrinsic relationship between protonation behavior and HA characteristics, especially in sediments. In this study, HA was extracted from sediments and combination of spectrographic titration with parallel factor analysis, Gaussian fitting model and two-dimensional correlation spectroscopy analysis was developed as a novel in-situ tool. Results indicated that the intensity changes of fluorophores of sediment HA might be dependent on the structure characteristics (fused or non-fused ring) of phenolic species in the protonation process. Compared with phenolic groups (A1, 5.27 ± 0.05 eV; A3, 3.91 ± 0.02 eV), the carboxyl groups (A2, 4.65 ± 0.03 eV) exhibited greater contribution in the response of chromophores to the protonation process of sediment HA. Furthermore, proton binding to sediment HA first occurred in carboxyl groups and then in phenolic groups. The combined technique is a promising approach for the examination of the binding sites, binding capacities, and binding order in proton-HA binding process under environmental concentrations. Importantly, this method is a sensitive, effective and non-destructive technique without any need pre-concentrate. |
| Databáze: | OpenAIRE |
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