基于光谱法的城市道路沉积物中DOM时空分布特征研究  

Research on the spatiotemporal distribution characteristics of DOM in urban road sediments based on spectral method

作　　者：王蔚洲 王渲 董妍 高琦 卢金锁[1] WANG Weizhou;WANG Xuan;DONG Yan;GAO Qi;LU Jinsuo(School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710043)

机构地区：[1]西安建筑科技大学,环境与市政工程学院,西安710043

出　　处：《环境科学学报》2025年第3期350-360,共11页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.51978558)。

摘　　要：选取西安市典型采样点18个,采集人行道和车行道两类道路沉积物,基于紫外-可见光谱和三维荧光光谱耦合平行因子分析方法,解析DOM组分,探究道路沉积物中DOM的时空分布特征.结果表明:①道路沉积物DOM解析出3种荧光组分:UVC类腐殖酸物质(C1)、一种生物可利用性较高的腐殖酸物质(C2)和类色氨酸物质(C3).车行道以C1组分为主,人行道以C3组分为主,显示了不同的源输入特征.②基于紫外-可见吸收光谱特征参数和三维荧光光谱特征参数的时空差异性可知:季节上,道路沉积物DOM浓度在春季达到峰值(79.1 mg·L^(-1)),冬季DOM的芳香化程度最高,夏季DOM分子量最大,成分构成相比于冬、春两季更稳定,微生物活动和分解产生的DOM占主导地位;空间上,车行道陆源外源输入特征强于人行道,车流量较大的地区和人口密度较高的区域,受到更多的外来人为因素影响,沉积物DOM浓度较高,陆源外源输入占比更大.此外,道路沉积物DOM受到周围环境特征因素的影响,如植被覆盖和土壤背景值等因素.This study investigated the spatial and temporal distribution characteristics of dissolved organic matter(DOM)in road sediments by selecting 18 typical sampling points in Xi'an city,focusing on two types of sediments:those from sidewalks and roadways.The analysis utilized ultraviolet-visible(UV-Vis)spectroscopy and three-dimensional fluorescence spectroscopy to characterize DOM components.The results revealed the following:①Three fluorescent components were identified in the road sediment DOM:UVC humic acid substance(C1),a highly bioavailable humic acid substance(C2),and tryptophan like substance(C3).Roadways were predominantly composed of C1 components,while sidewalks were primarily composed of C3 components,indicating distinct source input characteristics.②The spatiotemporal variation analysis based on UV-Vis absorption spectrum parameters and 3D fluorescence spectrum parameters showed that the DOM concentration in road sediments peaked in spring(79.1 mg·L^(-1)).The highest degree of DOM aromatization was observed in winter,while the molecular weight of DOM was largest in summer.During summer,the composition of DOM was more stable compared to winter and spring,with microbial activity and decomposition processes contributing predominantly to DOM production.Spatially,vehicular lanes exhibited stronger characteristics of external land-source inputs compared to sidewalks.Areas with higher traffic volume and population density were more influenced by external anthropogenic factors,resulting in higher DOM concentrations in sediments and a greater proportion of land-source inputs.Additionally,the study highlighted that the DOM in road sediments is also affected by surrounding environmental factors,such as vegetation cover and soil background values.

关 键 词：溶解性有机物 时空分布特征 紫外-可见吸收光谱 三维荧光光谱 城市道路沉积物 

分 类 号：X830[环境科学与工程—环境工程]