水溶性有机物与多环芳烃结合特征的红外光谱学研究

水溶性有机物（DOM）与多环芳烃（PAHs）之间的相互作用一直是尚未弄清的理论问题。对其正确阐释有利于更好地理解DOM对PAHs环境行为与生态效应的影响及科学地评估PAHs的环境风险，并对PAHs污染土壤的修复具有极其重要的意义。本研究以有机物料猪粪、污水污泥和带根茬水稻土作为DOM的提取材料，以菲（Phenanthrene，Phe）和芘（Pyrene，Pyr）为PAHs代表，采用红外光谱学技术研究DOM与PAHs的相互作用。红外图谱显示，供试DOM在4000—3000cm^-1、2969—2900cm^-1、1700-1375cm^-1、1300—1000cm^1和900-600cm^-1存在明显的吸收峰，这说明DOM中含有-OH或酚-OH、-NH、苯环、-C-O及-CH2等功能团。对比DOM与DOM—Phe／Pyr的图谱发现，DOM—Phe／Pyr在4000—3000cm^-1、1700—1375cm^-1和900—600cm^-1的吸收峰发生不同程度的朝长波方向飘移，表明NH-π和π-π作用参与了DOM与Phe及Pyr结合物的形成。

INFRARED SPECTROSCOPY OF DOM-PAHs COMPLEXES

The complexes of dissolved organic matter(DOM)and polycyclic aromatic hydrocarbons(PAHs)play an important role in environmental behaviors of PAHs.Interactions between DOM and PAHs are involved in forming complexes of DOM and PAHs.However,besides partitioning and hydrophobic effects,little is known of the interact ions between DOM and PAHs. In the paper,the interactions of DOMs derived from paddy soil,pig manure and sewage sludge respectively with phenanthrene (Phe)and pyrene(Pyr)were investigated with Fourier transform infrared(FT-IR)spectroscopy.With all the DOMs tested,asorption peaks were found in the bands of 4 000~3 000 cm^-1,2 969~2 900 cm^-1,1 700~1 375 cm^-1,1 300~1 000 cm^-1,and 900~600 cm^-1,suggesting that DOM contained O-H(hydrogen bonded alcohols,phenols and carboxylic acids),NH(amines),aromatic ring,C-O(polysacchrides,carboxyl),and-CH₂ function groups.Comparison of the FT-IR spectra of DOM and DOM-Phe/Pyr revealed that absorption peaks of DOM-Phe/Pyr in the bands of 4 000~3 000 cm^-1,1 700~1 375 cm^-1,and 900~600 cm^-1 shifted to longer wavelengths,indicating that there existed NH-π and π-π interact ions in the formation of complexes of PAHs and DOM.