Zhang Tao, Lu Jinfeng, Ma Jun, Qiang Zhimin
School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
Chemosphere. 2008 Mar;71(5):911-21. doi: 10.1016/j.chemosphere.2007.11.030. Epub 2008 Jan 10.
Fluorescence spectra were applied to investigate the structural changes of four dominant dissolved natural organic matter (DOM) fractions of a filtered river water before and after ozonation and catalytic ozonation. The ozonation and catalytic ozonation with synthetic goethite (FeOOH) and cerium dioxide (CeO(2)) were carried out under normal conditions, i.e. pH 7, reaction time of 10 min, and ozone/DOC ratio of about 1. The fluorescence spectra were recorded at both excitation-emission matrix (EEM) and synchronous scanning modes. EEM results reveal that ozonation of these DOM fractions causes a significant decrease of the aromaticity of humic-like structures and an increase of electron withdrawing groups, e.g., carboxylic groups. The catalysts can further improve the destruction of the humic-like structures in catalytic ozonation. Synchronous spectra reveal that ozonation of hydrophobic acid and hydrophilic acid (HIA) yields a significant amount of by-products with low aromaticity and low molecular weight. Catalytic ozonation enhances substantially the formation of these by-products from HIA and improves the destruction of highly polycyclic aromatic structures for all examined DOM fractions.
利用荧光光谱研究了过滤后河水中四种主要溶解性天然有机物（DOM）组分在臭氧化和催化臭氧化前后的结构变化。在正常条件下进行臭氧化以及用合成针铁矿（FeOOH）和二氧化铈（CeO₂）进行催化臭氧化，即pH值为7、反应时间为10分钟、臭氧与DOC的比例约为1。在激发 - 发射矩阵（EEM）和同步扫描模式下记录荧光光谱。EEM结果表明，这些DOM组分的臭氧化导致类腐殖质结构的芳香性显著降低，吸电子基团（如羧基）增加。催化剂可在催化臭氧化中进一步促进类腐殖质结构的破坏。同步光谱表明，疏水酸和亲水酸（HIA）的臭氧化产生大量低芳香性和低分子量的副产物。催化臭氧化大大增强了HIA中这些副产物的形成，并改善了所有检测的DOM组分中高度多环芳烃结构的破坏。
