热处理修复对土壤胡敏酸含量及光谱特征的影响  

Effects of Heating on Spectral Characteristics and Humic Acid Content of Soil

作　　者：黄兆琴[1] 吉栋梁 庞燕华 胡林潮[2] HUANG Zhaoqin;JI Dongliang;PANG Yanhua;HU Linchao(College of Environment and Ecology,Jiangsu Open University,Nanjing 210017,China;School of Environmental Sciences and Engineering,Changzhou University,Changzhou 213164,Jiangsu,China)

机构地区：[1]江苏开放大学环境生态学院,南京210017 [2]常州大学环境科学与工程学院,江苏常州213164

出　　处：《有色金属（冶炼部分）》2023年第12期104-114,共11页Nonferrous Metals（Extractive Metallurgy)

基　　金：江苏省科技厅产学研合作项目(BY2022669);江苏省高校青蓝工程项目(2021SZJS-003)。

摘　　要：为研究热处理修复对土壤胡敏酸含量和结构特征的影响,将3种土壤样品于200、250、300℃下分别加热2、4、6 h,对热处理前后土壤的胡敏酸(HA)进行了紫外光谱、三维荧光和红外光谱分析。结果表明:随着加热温度和时间的增加,HA的含量逐渐减少,HA与富里酸(FA)的比值(HA FA,胡富比)则逐渐增加;热处理使胡敏酸的芳香部分比例、腐殖化程度、平均分子量均增加,使胡敏酸更趋于稳定。供试土壤HA的三维荧光光谱也显示,HA荧光峰强度随加热温度增加而增加,表明HA中芳香类物质增加。热处理对土壤胡敏酸官能团数量有明显的影响,200℃或250℃加热时间少于6 h时,HA中具有更多的脂族成分,复杂结构减少,300℃加热时脂族结构成分减少,芳香结构物质增加;250℃加热6 h和300℃加热后碳水化合物或多糖则大量分解。因此,从不破坏土壤本身肥力和自净能力方面考虑,200℃或250℃加热时间不超过6 h是热修复最适宜的加热强度。In order to explore the effect of heating on content and structure of humic acid in soil,three soil samples were heated at 200,250,300℃for 2,4,6 h,respectively.UV-VIS spectra,3D fluorescence and infrared spectroscopy were used to demonstrate the changes of humic acid(HA)in soil before and after heating.The results show that the content of humic acid drops and ratio of HA to fulvic acid(FA)in soil after heating increases while the heating temperature and time increase.It indicates that heating can increase the proportion of aromatic parts,the degree of humification and the average molecular weight of humic acid,which makes humic acid more stable.For 3D fluorescence spectra,the fluorescence peak intensity of HA rises with the increase of heating temperature,which indicating that the aromatic substances in HA increase.The number of functional groups of HA is changed after heating.HA possesses more aliphatic components when the soil samples are heated on 200℃or 250℃for less than 6 h,but the aliphatic components decreases while the aromatic components increase when the soil samples are heated at 300℃.What′s more,after heating at 250℃for 6 h and 300℃,carbohydrates or polysaccharides are decomposed in large quantities.Therefore,in terms of never damaging the soil′s own fertility and self-purification capacity,the heating time of 200℃or 250℃for no more than 6 h may be the most suitable heating intensity for thermal remediation of soil.

关 键 词：胡敏酸 热处理 紫外光谱 三维荧光光谱 红外光谱 

分 类 号：X53[环境科学与工程—环境工程]