摘要
为探明生物质热解烟雾衍生的溶解性有机质(BSDOM)在水铁矿上的分馏特征及机制,本研究选取3种生物质来源(杉木、水稻秸秆和苜蓿)的BSDOM开展水铁矿吸附实验,通过紫外、红外和三维荧光光谱等技术分析了分馏前后溶液中BSDOM的有机组成和分子变化特征.研究发现BSDOM主要由类蛋白物质(57%~75%)构成,吸附机制以阳离子-π相互作用为主.分子量大、高芳香性物质更易吸附在水铁矿上,且多酚类物质优先被吸附.酸性条件可增强水铁矿与BSDOM之间的阳离子-π相互作用和配体交换,有利于吸附.而在高pH值(10.0~12.0)下,多酚类和短波类蛋白物质的吸附比增加,归因于氢键作用,长波类蛋白物质和类腐殖酸的吸附比降低是由于静电斥力的增强.本研究从分子角度揭示了BSDOM在水铁矿表面的分馏特征,有助于深入了解BSDOM在地表环境中的跨介质环境行为.
In order to explore the fractionation characteristics and mechanisms of biomass-pyrogenic smoke-derived dissolved organic matter(BSDOM)on ferrihydrite,this study selected BSDOM derived from three biomass sources(fir-wood chips,rice straw,and alfalfa)to investigate its adsorption on ferrihydrite.The organic compositions and molecular variations of BSDOM in the solution before and after fractionation were characterized using ultraviolet-visible(UV-Vis)spectroscopy,Fourier transform infrared(FTIR)spectroscopy and three-dimensional excitation-emission matrix(3D-EEM)fluorescence spectroscopy.The results indicated that BSDOM primarily consisted of protein-like substances(57%~75%),with cation-πinteractions identified as the dominant adsorption mechanism.High molecular weight and highly aromatic compounds exhibited stronger adsorption affinity to ferrihydrite,with polyphenols being preferentially adsorbed.The results demonstrated that acidic conditions enhanced cation-πinteractions and ligand exchange between ferrihydrite and BSDOM,thereby promoting adsorption.At high pH(10.0~12.0),the adsorption of polyphenols and short-wave protein-like substances increased,likely due to hydrogen bonding.In contrast,the adsorption of long-wave protein-like substances and humic-like substances decreased,primarily because of increased electrostatic repulsion.This study elucidates the fractionation characteristics of BSDOM on ferrihydrite surfaces at a molecular level,providing insights into the cross-media environmental behavior of BSDOM in surface environments.
作者
姚舒馨
钟寅华
徐忆欣
张慧颖
陈卫锋
倪进治
魏然
YAO Shu-xin;ZHONG Yin-hua;XU Yi-xin;ZHANG Hui-ying;CHEN Wei-feng;NI Jin-zhi;WEI Ran(School of Geographical Science,Fujian Normal University,Fuzhou 350007,China;Institute of Geography,Fujian Provincial Key Laboratory for Plant Eco-physiology,Fujian Normal University,Fuzhou 350007,China;Key Laboratory for Humid Subtropical Eco-Geographical Processes of the Ministry of Education,Fujian Normal University,Fuzhou 350007,China)
出处
《中国环境科学》
北大核心
2025年第10期5422-5434,共13页
China Environmental Science
基金
国家自然科学基金资助项目(42077130)
福建省自然科学基金资助项目(2024J01447)。
