垃圾渗滤液水溶性有机物荧光谱特性研究

选取不同填埋年限的垃圾渗滤液样品，利用荧光检测技术，分析了渗滤液水溶性有机物(DOM)组成变化。DOM荧光同步扫描光谱表明，在填埋的0～5年，结构简单的化合物在较短波长(335，385 nm)的特征峰荧光强度急剧降低，而在5～10年的降低幅度较小。DOM三维荧光光谱显示，填埋0年，垃圾渗滤液DOM产生2个类蛋白荧光峰(Ex/Em = 270 nm/355.5 nm和Ex/Em=220 nm/350 nm)；而填埋5年后，类蛋白荧光峰消失，形成2个分子结构复杂的类富里酸荧光峰(Ex/Em=330 nm/412.5 nm和Ex/Em=250 nm/416.5 nm)，表明DOM分子中简单化合物减少，缩合度高的化合物增加。而后随着填埋时间的推移，DOM成分相对稳定，以富里酸类物质为主，但其数量及芳构化程度则呈增加的趋势。以上结果证实，随着填埋年限的增加，DOM分子呈复杂化趋势。

Study on Fluorescence Characteristic of Dissolved Organic Matter from Municipal Solid Waste Landfill Leachate

In the present study,the samples of leachate of 0,5,10-years-old landfill were respectively taken from landfill plant,the dissolved organic matter(DOM) was extracted from landfill leachate,and the fluorescence spectra of DOM were determined.The fluorescence synchronous scan spectra of DOM in 0-year-old leachate exhibited a primary peak at 335 nm,a secondary peak at 455 nm,and a shoulder peak at 385 nm.While the fluorescence intensities of DOM at different peaks were decreased for 5-year-old leachate,especially those of the peaks at shorter wavelengths(335 and 385 nm) which may be ascribed that the simpler structural components were decreased sharply.Compared with 5-year-old leachate,the fluorescence intensity of DOM in 10-year-old leachate decreased slightly.Three-dimensional excitation emission matrix fluorescence spectra(3DEEM) of DOM in 0-year-old leachate exhibited two peaks at Ex/Em wavelength pairs of 270/355 and 220/350,respectively,which were all associated with protein-derived compounds,while the peaks of protein-like disappeared in 5-year-old leachate,and new peaks of complex structural fulvic acid-like were formed at Ex/Em wavelength pair of 330/412.5 and 250/416.5,respectively.This indicated the component of DOM in the leachate of 5-year-old landfill led to a decrease in low molecular compound,and an increase in high molecular compound compared to that of the 0-year-old.3DEEM of DOM of 10-year-old leachate was similar to that of DOM in the 5-year-old,but the fluorescence intensity of the peaks of fulvic acid-like in DOM was different,and compared with that of 5-year-old leachate,the peak of DOM in 10-year-old leachate shifted from Ex/Em wavelength pair of 250/416.5 to 250/427.5.This indicated that the DOM formed similar structures,but the structure of fulvic acid-like in DOM of 10-year-old leachate had a greater degree of aromatization and quantity than that of 5-year-old leachate.The results obtained from fluorescence synchronous scan spectroscopy and 3DEEM indicate that aromatic structures of DOM are enriched with the age of landfill leachate.