乌梁素海周边土壤溶解性有机质荧光特性及其与Cu(Ⅱ)的配位研究  

THE FLUORESCENCE PROPERTIES AND COMPLEXATION WITH Cu(Ⅱ) OF DISSOLVED ORGANIC MATTER IN SOIL AROUND WULIANGSUHAI LAKE

作　　者：郭旭晶[1,2] 席北斗[2] 何小松[1,2] 于会彬[1,2] 马文超[2,3] 

机构地区：[1]北京师范大学环境学院,北京100875 [2]中国环境科学研究院水环境系统工程研究室,北京100012 [3]中国地质大学(北京)工程技术学院,北京100083

出　　处：《环境化学》2010年第6期1121-1126,共6页Environmental Chemistry

基　　金：国家水体污染控制与治理科技重大专项(2008ZX07106-001);国家科技支撑计划课题项目(2006BAC06B04)

摘　　要：应用三维荧光光谱研究了乌梁素海周边4种土壤的溶解性有机质荧光特性以及与Cu(Ⅱ)的相互作用.研究结果表明,土壤溶解性有机质具有两个明显的荧光峰(峰A和峰C),且峰A和峰C具有明显的相关性(R2=0.980,P<0.001),表明它们具有类似的结构或相同的来源;土壤阳离子交换量(CEC)影响DOM的荧光强度,随着CEC的增加,荧光强度有逐渐增强的趋势.同时,CEC还与有机质的成熟度和结构有关,随着CEC的增加,土壤有机质的腐殖化程度增强;有机质的荧光指数f450/500值分布在1.55—1.79之间,总体而言,f450/500的值接近于1.6,说明土壤中的腐殖质既有生物源也有陆源,但主要来源为陆源;土壤溶解性有机质的两个类富里酸(峰A和峰C)与Cu(Ⅱ)的络合常数依次为lgKA=5.3107—5.8303,lgKC=5.0721—5.7924,配位荧光基团比例fA为44.20%—69.82%,fC为52.25%—81.88%,显示土壤溶解性有机质中荧光基因与Cu(Ⅱ)络合能力较大,能与Cu(Ⅱ)配位的配位基较多。Four soil samples were collected from the surrounding areas of Wuliangsuhai Lake for our study：RF,an abandoned farmland;RH,agricultural soils planted wheat;YB,a soil with vegetation named Salicornia europaea,and YZD,grown Kalidium foliatum community.Three depths of sample were chosen（0—20cm,20—40cm,40—60cm） for each soil at the four locations.Excitation-emission matrix fluorescence spectroscopy（EEMs） was applied to measure the fluorescence properties of dissolved organic matter（DOM） and DOMCu（Ⅱ） complexation.The results indicate that dissolved organic matter extroeted from soil has two fulvic acid-like fluorescence peaks（peak A and peak C）.The fluorescence intensity of peak A and peak C has significant correlation,suggesting similar structure or source.The cation exchange capacity is a factor for influencing humification degree.At the excitation wavelength of 370nm,the value of f450/500 is 1.55—1.79,indicating that soil DOM originated form both biogenic and terrigenous sources.DOM-Cu（Ⅱ） complexation constants（lgKA = 5.3107—5.8303,lgKC = 5.0721—5.7924） show that the complexation ability of the four soil DOMs is similar.The proportion of complexation fluorescence group（fA = 44.20% —69.82%,fC = 52.25% —81.88%） demonstrated that the fluorescent groups interacted more strongly with Cu（Ⅱ） more.

关 键 词：土壤溶解性有机质 三维荧光光谱 配位 

分 类 号：X131.3[环境科学与工程—环境科学]