微生物陈化可提升麦秆水热炭对Cd^2+吸附性能  

Microbial aging can improve the Cd^2+ adsorption performance of wheat straw hydrochar in aqueous solution

作　　者：花昀 刘杨[3] 冯彦房[2,4] 何华勇 杨梖 杨林章 薛利红[2,4] HUA Yun;LIU Yang;FENG Yan-fang;HE Hua-yong;YANG Bei;YANG Lin-zhang;XUE Li-hong(College of Resources and Environmental Sciences,Nanjing Agricultural University,Nanjing 210095,China;Key Laboratory of Agro-Environment in Downstream of Yangtze Plain,Ministry of Agriculture and Rural Affairs,Institute of Agricultural Resources and Environment,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China;Institute of Agricultural Information,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China;School of Environmental and Safety Engineering,Jiangsu University,Zhenjiang 212001,China)

机构地区：[1]南京农业大学资源与环境科学学院,南京210095 [2]江苏省农业科学院农业资源与环境研究所,农业农村部长江下游平原农业环境重点实验室,南京210014 [3]江苏省农业科学院农业信息研究所,南京210014 [4]江苏大学环境与安全工程学院,江苏镇江212001

出　　处：《农业环境科学学报》2020年第7期1613-1622,共10页Journal of Agro-Environment Science

基　　金：国家自然科学基金项目(41877090);国家水体污染控制与治理科技重大专项(2017ZX07202004-003);长江下游平原农业环境重点实验室开放基金(AE2018006);省部共建国家重点实验室培育基地——江苏省食品质量安全重点实验室自主研究课题(2019zh001)。

摘　　要：为提升水热炭对Cd^2+的吸附性能,使用麦秆水热炭,在厌氧发酵条件下对其进行微生物陈化改良,通过扫描电镜(SEM)、比表面积和孔分析(BET)、红外光谱分析(FTIR)、X射线光电子能谱分析(XPS)等现代技术手段对水热炭微生物改良前后的表面特性进行了系统表征,并通过吸附实验考察了微生物陈化过程对水热炭吸附Cd^2+的过程及机制。结果表明:随陈化时间的增加,水热炭的比表面积提升近5倍;pH由酸性逐渐接近中性;水热炭陈化后表面负电荷增多;O/C增加、H/C减少;表面C-C键强度降低,而含氧官能团相对强度增加。微生物陈化过程显著提升了水热炭对Cd^2+的吸附能力。微生物陈化水热炭对Cd^2+的吸附能力与体系pH值和温度呈正相关。微生物陈化水热炭对Cd^2+的吸附机制以化学吸附为主导,主要为单分子层均相吸附;官能团络合、表面静电作用、离子交换、π键配位作用对Cd^2+的吸附起到了重要作用。研究表明,微生物陈化处理可显著改变水热炭的孔隙结构并提升对Cd^2+的吸附性能。Hydrochar has good prospects for agricultural and environmental application.However,modifications are required to improve the Cd^2+ adsorption performance of wheat straw hydrochar in aqueous solution.In this study,microbial aging was conducted under anaerobic fermentation conditions to improve the hydrochar derived from wheat straw(WHC).The surface characteristics before and after hydrothermal charcoal microbial treatment were systematically characterized by means of scanning electron microscopy(SEM),specific surface area and pore analysis(BET),infrared spectroscopy(FTIR),and X-ray photoelectron spectroscopy(XPS).Moreover,the process and mechanisms of Cd^2+ adsorption by hydrochar were studied using adsorption experiments.The following results were obtained:The specific surface area of hydrochar increased nearly 5 times as the duration of microbial aging increased.The pH changed from acidic to neutral.The surface negative charges increased after aging.The O/C increased,but H/C decreased as aging progressed.The strength of surface C-C bonds decreased,while the relative intensity of oxygen-containing functional groups increased.The microbial aging process significantly increased the Cd^2+adsorption capacity of hydrochar.The Cd^2+ adsorption capacity of microbially aged hydrochar showed positive correlations with the pH and temperature in the system.Chemical adsorption was the major Cd^2+ adsorption mechanism of microbially aged hydrochar;it consisted mainly of monolayer homogeneous adsorption,while the complexation of functional groups,surface electrostatic interactions,ion exchange,and π bond coordination also played significant roles in Cd^2+ adsorption.This study illustrates that microbial aging can significantly change the pore structure of hydrochars and improve the Cd^2+ adsorption performance of wheat straw hydrochar in aqueous solution.

关 键 词：水热炭 微生物陈化 CD^2+ 吸附机制 

分 类 号：X703[环境科学与工程—环境工程]