过硫酸盐氧化降解2,4-二硝基甲苯的光谱特征变化解析  

Spectroscopic Characterization of 2,4-Dinitrotoluene Degradation by Persulfate Activation with Zero-Valent Iron

作　　者：马志飞 孙海洋 杨天学[2] 熊卿 杨昱[2] 曹侃 曹华莉 吴代赦 MA Zhi-fei;SUN Hai-yang;YANG Tian-xue;XIONG Qing;YANG Yu;CAO Kan;CAO Hua-li;WU Dai-she(Key Laboratory of Poyang Lake Environment and Resource Utilization,Ministry of Education,School of Resources Environmental&Chemical Engineering,Nanchang University,Nanchang 330031,China;State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;Environmental Monitoring Department of Jiangxi Province,Nanchang 330077,China)

机构地区：[1]南昌大学资源环境与化工学院鄱阳湖环境与资源利用教育部重点实验室,江西南昌330031 [2]中国环境科学研究院环境保护地下水污染模拟与控制重点实验室,北京100012 [3]江西环境监测中心站,江西南昌330077

出　　处：《光谱学与光谱分析》2020年第3期849-854,共6页Spectroscopy and Spectral Analysis

基　　金：国家重大专项(2017ZX07301005-001-01);国家自然科学基金项目(51608499)资助

摘　　要：随着人类活动不断增加,难降解有机物已成为污染地下水主要物质之一。贫营养、厌氧的地下水环境将加剧难降解有机物的长期风险。2,4-二硝基甲苯(2,4-DNT)作为难降解的硝基苯类物质,对其污染地下水修复治理一直是环境领域的难点和热点问题。目前,零价铁活化过硫酸盐高级氧化技术被用于修复地下水中2,4-DNT,具有较高的效率。为了更好地识别降解过程,一般采用质谱识别氧化降解的中间产物和降解产物以及生成的顺序,但无法有效的识别氧化降解过程中有机物官能团的变化顺序。因此,采用三维荧光技术、傅里叶红外光谱技术以及二维相关分析技术耦合识别过硫酸盐氧化体系中2,4-DNT的光谱变化及官能团转化顺序。结果表明,未出现荧光峰的2,4-DNT降解生成的具有荧光基团的新产物,反应初期荧光产物的生成主要是因苯环上硝基的变化,而苯环未受到破坏。通过对5个区域体积积分可知,随着反应进行苯环破裂,生成不饱和脂肪酸,类富里酸结构的产物不断被降解,而类腐殖质结构的产物后期逐渐被降解,导致区域Ⅱ和区域Ⅳ中积分的荧光强度占比不断增加,后期产物中的2,4-二氨基甲苯(2,4-DAT)含量不断增加,导致体系中的荧光不断增强,其来源于过量的Fe0还原2,4-DNT反应;红外吸收峰主要有3334,2844,2954,2357,2126,1643,1410,1110和700 cm^-1,表明产物中主要官能团有氨基、亚甲基、羧基、酚羟基及烯烃类等,但不同反应阶段的红外吸收峰差异性较小,表明氧化体系中苯环上甲基被氧化为羧基或酚羟基,硝基被还原转化为氨基,苯环破坏生成不饱和脂肪酸和烯烃类结构物质。通过对时间变化过程中水相的FTIR数据进行二维相关分析,发现同步谱图中出现了4个自相关峰,其位置为λ1/λ2=3334/3334,1643/1643,1015/1015和700/700,同时在λ1/λ2=1643/3334,1015/3334,700/3334,1015/1634,700/1634和700/1015处出现With the intensification of human activities,refractory organic compounds have become one of the groundwater pollutants.groundwater is a nutrient-poor and anaerobic environment,which will aggravate the long-term risk of refractory organic matter.Therefore,the remediation of groundwater contaminated by 2,4-dinitrotoluene has been a difficult and hot issue in the field of environment.Currently,Fe0 activated persulfate technology is widely used to repair 2,4-DNT in groundwater.In order to identify the degradation process,mass spectrometry is generally used to identify the intermediate products and degradation products of oxidative degradation and the order of formation.However,it is unable to effectively identify the change order of organic functional groups in the process of oxidative degradation.Therefore,three-dimensional excitation emission matrix fluorescence spectroscopy(3 D-EEM),Fourier transform infrared spectroscopy(FTIR),and two-dimensional correlation analysis were applied to investigate the composition of products and the variation of functional groups over time in the persulfate oxidation system.The results showed that 2,4-dinitrotoluene showed no fluorescence peak,but its products with fluorescence groups were generated.As the benzene ring broken down in the reaction,the unsaturated fatty acids might generated.With the increase of reaction time,the products with the structure of fulvic acid degraded continuously,while the products with the structure of humic-like degraded gradually in the later stage.The proportion of zone II and IV increased,which was mainly due to the increasing content of 2,4-diaminotoluene in the products.Infrared absorption peaks were mainly 3334,2844,2954,2357,2126,1643,1410,1110 and 700 cm^-1.The functional groups of the products were mainly amino,methylene,carboxyl,phenol hydroxyl and olefin methyl.But the difference of infrared absorption peak was not significantly with time.Two-dimensional correlation analysis was performed on FTIR during the time change process.Four auto-pea

关 键 词：过硫酸盐 2 4-二硝基甲苯 三维荧光 傅里叶变换红外光谱 二维相关分析 光谱特征 

分 类 号：O656.4[理学—分析化学]