生物炭中溶解性有机质与Cu(Ⅱ)的络合机制研究  

Complexation Between Cu(Ⅱ)and Dissolved Organic Matter from Biochar

作　　者：张军[1,2] 王薇 储刚 周丹丹[1,2] 赵婧 王琳[1,2] 李芳芳 ZHANG Jun;WANG Wei;CHU Gang;ZHOU Dandan;ZHAO Jing;WANG Lin;LI Fangfang(Faculty of Environmental Science and Engineering,Kunming University of Science and Technonlogy,Kunming 650500,China;Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control,Kunming 650500,China)

机构地区：[1]昆明理工大学环境科学与工程学院,昆明650500 [2]云南省土壤固碳与污染控制重点实验室,昆明650500

出　　处：《材料导报》2021年第22期22160-22165,共6页Materials Reports

基　　金：国家自然科学基金(41703121,41703111);昆明理工大学人才启动项目(KKSY201722006,KKSY201506058);云南省重点研发计划资助(2018BC004)。

摘　　要：生物炭是废弃生物质在厌氧条件下热解产生的固体产物,因其具有多孔、含氧官能团、比表面积较大及矿物质较为丰富等优点而在重金属污染土壤修复方面具有良好的应用前景。生物炭对重金属迁移性的影响因素有重金属特性、生物炭固体颗粒及其所含溶解性有机质(DOM)的特性。生物炭进入环境后,生物炭中的DOM易随环境介质发生迁移转化且DOM含有较丰富的含氧官能团,其与重金属的相互作用对重金属的迁移转化有重要影响。然而,生物炭DOM的特性受生物炭母质来源和热解温度的影响,不同源生物炭中DOM与重金属相互作用机制尚不明确。因此,深入研究生物炭DOM与重金属之间的相互作用机制对评估生物炭对重金属的迁移影响至关重要。本研究采用多种光谱技术,探讨了生物炭中DOM的组成及其与Cu(Ⅱ)的络合特性。结果表明,SUVA_(254) DOM和SUVA_(260) DOM属于芳香性很低的亲水性材料,且玉米秸秆生物炭DOM(MDOM)浓度高于松木生物炭DOM(PDOM)浓度;三维荧光光谱鉴定出DOM主要由类腐殖酸和类富里酸构成;与PDOM相比,MDOM中含有更多的荧光物质(类富里酸和类腐殖酸),为其与Cu(Ⅱ)的络合提供了结合位点,因此其络合稳定常数高于PDOM;^(1)H-NMR证明DOM中酚羟基官能团与Cu(Ⅱ)发生了明显的络合作用。本研究将为生物炭作为功能性材料在环境修复中的应用提供筛选依据以减低其环境风险。Biochar is a solid product produced by pyrolysis of waste biomass under anaerobic oxygen conditions.Because of its porosity,large specific surface area,rich oxygen-containing functional groups,rich minerals and so on,biochar has been widely used in the remediation of heavy metal contaminated soils.The migration effect of biochar on heavy metals is affected by not only the properties of heavy metals and the solid particles of biochar,but also the dissolved organic matter from biochar.Dissolved organic matter(DOM)from biochars has significant mobility after the application of biochars in the environment.The interaction between functional groups of DOM and heavy metals is an important mechanism of heavy metal migration and transformation.The characteristics of DOM are determined by the raw materials of biochars and pyrolysis temperature.However,DOM characteristics as affected by the interaction between DOM and heavy metals were not extensively studies.Therefore,in-depth study of the interaction between biochar DOM and heavy metals is essential to assess the impact of biochar on the migration of heavy metals.In this study,a variety of spectroscopic techniques were used to explore the composition of DOM in biochar and its complexing characteristics with Cu(Ⅱ).The results showed that the SUVA_(254) DOM and SUVA_(260) DOM belonged to hydrophilic materials with very low aromaticity,and the concentration of MDOM was higher than that of PDOM.The EEM identified that the mainly composed of DOM were fulvic-like acid and humic-like acid.The MDOM has more fluorescent substances(fulvic-like acid and humic-like acid)that provide binding sites for Cu(Ⅱ),thus making the complexation stability constant higher than PDOM.^(1)H-NMR proved that the phenolic hydroxyl groups of DOM have obvious complexation with Cu(Ⅱ).This study will provide a screening basis for the application of biochar as a functional material in environmental remediation,and reduce its environmental risk.

关 键 词：生物炭 溶解性有机质(DOM) Cu(Ⅱ) 荧光淬灭 结合能力 

分 类 号：X131.2[环境科学与工程—环境科学]