不同生态混凝土坡岸中溶解性有机质与镉的相互作用机理研究  

Interaction Mechanism of Dissolved Organic Matter and Cadmium in Different Ecological Concrete Slopes

作　　者：梁明欣 寇莹莹[2] 王京刚[1] 何连生[3] 张琪 徐红灯 袁冬海[2] LIANG Mingxin;KOU Yingying;WANG Jinggang;HE Liansheng;ZHANG Qi;XU Hongdeng;YUAN Donghai(College of Chemical Engineering,Beijing University of Chemical Technology,Beijing 100029,China;Key Laboratory of Urban Stormwater System and Water Environment,Ministry of Education,Beijing University of Civil,Engineering and Architecture,Beijing 102616,China;Chinese Research Academy of Environmental Sciences,Beijing 100012,China;China Railway 11th Bureau Group No.5 Engineering Co.,Ltd.,Chongqing 400037,China)

机构地区：[1]北京化工大学化学工程学院,北京100029 [2]北京建筑大学,城市雨水系统与水环境教育部重点实验室,北京102616 [3]中国环境科学研究院,北京100012 [4]中铁十一局集团第五工程有限公司,重庆400037

出　　处：《环境科学研究》2020年第8期1857-1868,共12页Research of Environmental Sciences

基　　金：北京建筑大学市属高校基本科研业务费专项资金(No.X18288,X18289);中铁十一局集团第五工程有限公司科研项目(No.18-AII-08)。

摘　　要：为研究生态混凝土坡岸中DOM (dissolved organic matter,溶解性有机质)与重金属离子的相互作用,通过FQT(fluorescence quenching titration,荧光淬灭滴定)试验配合3D-EEMs (three-dimensional fluorescence spectroscopy,三维荧光光谱)、PARAFAC (parallel factor,平行因子分析)和2D-COS (two-dimensional correlation spectroscopy,二维相关光谱)探究了AEC(applied eco-concrete,应用型生态混凝土)和IEC (improved eco-concrete,改良型生态混凝土)坡岸中DOM与Cd^2+的相互作用机理.结果表明:①3D-EEMs结果显示,AECow(AEC坡岸出水)类蛋白组分荧光强度降低,水体腐殖化程度升高,而IECow(IEC坡岸出水) DOM各组分荧光强度均降低;Cd^2+能与DOM中所有组分发生络合,且随c(Cd^2+)增加,各组分的荧光强度最终趋于稳定.②PARAFAC将所有样品中DOM分离出类蛋白、类富里酸和类腐殖质3个独立组分,其中类富里酸组分随c(Cd^2+)增加表现稳定的荧光淬灭效果.③通过Ryan and Weber模型计算Cd^2+与DOM中各组分的络合常数(lg K)发现,所有样品中Cd2+与DOM中类富里酸组分的lg K值均大于类蛋白组分.进一步发现,不同坡岸出水lg K值大小依次为RW(原水)>AECow>IECow;④2D-COS分析得出,DOM中类蛋白组分对Cd^2+的敏感度最大.RW中Cd^2+与DOM位点的络合顺序为340 nm→273 nm→282 nm,AECow中络合顺序为410 nm→330 nm.研究显示:Cd^2+率先与DOM中类富里酸、腐殖质类物质络合,且络合能力强,类蛋白物质最容易受Cd^2+的干扰;AECow增加了下游水生态系统中Cd^2+的迁移风险和生物有效性,相反IECow则降低了Cd^2+的迁移风险,两种坡岸均能降低DOM组分与Cd^2+的络合能力,其中IEC坡岸最优.In order to study the interaction of DOM (dissolved organic matter) with heavy metals in ecological concrete slopes,the interaction between DOM and Cd2+ in AEC (applied ecological concrete) and IEC (improved ecological concrete) slopes was explored by FQT (fluorescence quenching titration) experiment,3D-EEMs (three-dimensional fluorescence spectroscopy),PARAFAC (parallel factor) and 2D-COS (two-dimensional correlation spectroscopy). The results indicated that: (1) 3D-EEMs showed that the fluorescence intensity of the protein-like components in the effluent of the AEC slope decreased,and the degree of humification of the water increased,while the fluorescence intensity of the DOM components in the effluent from the IEC slope decreased. Cd2+ could complex with all components in DOM,and as the cadmium ion concentration increased,the fluorescence intensity of each complexation tended to be stable. (2) PARAFAC separated DOM from all samples into three independent components,namely proteinoid,humic acid and fulvic acid. The fulvic acid showed stable fluorescence quenching with increasing Cd^2+ concentration. (3) Through the complex stability constant (lg K value) calculated by Ryan and Weber model,it was found that the lg K value of fulvic acid-like components and Cd^2+ in DOM was higher than that of protein-like components. It was further found that the lg K value was RW (raw water) > AECow> IECowin different sloping waters. (4) 2D-COS analysis showed that the protein-like components in DOM were most sensitive to Cd2+. The complexation order of Cd2+and DOM sites in RW was 340 nm→273 nm→282 nm,and the complexation order of AECow slope effluent was 410 nm→330 nm.The research shows that,Cd^2+ has the highest complexing affinity with fulvic acid like and humus like substances in DOM,and has strong complexing ability,while protein-like substances are most susceptible to interference by Cd^2+. The effluent of the AECow slope increases the migration risk and bioavailability of Cd^2+ in the downstream water ecosystem,wh

关 键 词：生态混凝土 三维荧光光谱(3D-EEMs) 二维相关光谱(2D-COS) 溶解性有机质(DOM) CD^2+ 

分 类 号：X52[环境科学与工程—环境工程]