Insight into the Soil Dissolved Organic Matter Ligand–Phenanthrene-Binding Properties Based on Parallel Faction Analysis Combined with Two-Dimensional Correlation Spectroscopy

Dissolved organic matter (DOM) can strongly bind to organic contaminants and control phenanthrene in soil. Herein, four individual parallel factor analysis (PARAFAC) components were found in soil DOM. Component C1 was the humic-like component ligand T, and component C2 was a combination of humic fluorophore ligands M1 and M2. Furthermore, components C3 and C4 were characterized as terrestrial and ubiquitous humic substances. Then, the modified Stern-Volmer complexation model was used to reveal soil DOM component-phenanthrene-binding properties. The overall binding characteristics of a PARAFAC component could not express the phenanthrene-binding properties. Therefore, two-dimensional correlation spectroscopy was used to reveal DOM ligand-phenanthrene-binding properties. After binding with phenanthrene, DOM ligands T, M2, A2, and C1 were quenched but DOM ligands M1, A1, and C2 were excited. The ligands with higher humification presented higher phenanthrene-binding ability. With these promising results, the DOM ligand-phenanthrene-binding characteristics offered theoretical support for soil pollution control.