北方某组合人工湿地冬季水体溶解性有机质的光谱特征

SPECTRA CHARACTERISTICS OF DISSOLVED ORGANIC MATTER OF THE COMBINED CONSTRUCTED WETLANDS IN WINTER IN NORTHER CHINA

采用紫外可见吸收光谱(UV-Vis)和三维荧光光谱结合平行因子(EEM-PARAFAC)分析方法,对北方某组合人工湿地(表流-水平流-垂直流)冬季水体溶解性有机质(DOM)的来源、光谱特性和演变过程进行研究,以期为深入理解冬季人工湿地对有机物的去除过程和作用机理提供科学依据。结果表明:冬季人工湿地对于有机物的去除具有一定作用,但去除效果不明显。UV-Vis和EEM-PARAFAC都表明人工湿地水体DOM中类腐殖物质浓度要高于类蛋白质物质,平行因子分析解析出人工湿地水体DOM含有3个主要的荧光组分,分别为陆源类腐殖质(400,525 nm)、可见区类富里酸(325,420 nm)和类色氨酸(210,330 nm),且3个组分具有显著的同源性。光谱指数表明该湿地水体DOM的来源以生物来源为主,且腐殖化特征较为微弱。

The source,optical properties,and evolution process of dissolved organic matter(DOM)of the combined constructed wetlands(surface flow-subsurface flow)in winter in northern China were studied by using ultraviolet-visible spectroscopy(UV-Vis)and three-dimensional fluorescence spectroscopy coupled with parallel factor analysis(EEMPARAFAC).This study provides an important scientific basis for further understanding the removal process and mechanism of organic matter in the constructed wetlands in winter.The results show that the constructed wetland has a certain effect on the removal of organic matter in winter,but the removal efficiency is not obvious.Both UV-Vis and EEM-PARAFAC indicate the amounts of humic-like substances in the constructed wetland water DOM were higher than that of protein-like substances.According to the parallel factor analysis,three main fluorescent components were identified in the constructed wetlands DOM,including terrestrial humus components(400/525 nm),fulvic acid-like components(325/420 nm),and tryptophan-like components(210/330 nm),and the three components had significant homology.In addition,the fluorescence indexes showed that DOM in the constructed wetlands was mainly from biological sources,and with weak humification characteristics.