流化床制备玉米秸秆生物炭的Pb^(2+)吸附特性及机理  

Pb^(2+)adsorption characteristics and mechanism of corn stalk biochar produced by fluidized bed

作　　者：刘凌沁[1] 黄亚继[1] 胡华军[1] 曹健华 Liu Lingqin;Huang Yaji;Hu Huajun;Cao Jianhua(Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education,Southeast University,Nanjing 210096,China)

机构地区：[1]东南大学能源热转换及其过程控制教育部重点实验室,南京210096

出　　处：《东南大学学报（自然科学版）》2022年第4期666-675,共10页Journal of Southeast University：Natural Science Edition

基　　金：国家重点研发计划资助项目(2018YFC1901205).

摘　　要：选取玉米秸秆作为原料,在流化床反应器中进行热解以获得不同热解温度以及不同低氧氛围下的生物炭,研究其理化特性及Pb^(2+)吸附性能,并定性及定量分析了吸附过程的吸附机理.实验结果表明:玉米秸秆生物炭对Pb^(2+)的吸附在12 h后达到平衡,吸附过程符合Langmuir模型和准二级动力学模型,说明吸附为发生在生物炭均质表面的单分子层吸附并以化学吸附为主;在较高热解温度下,离子交换和官能团络合的吸附作用贡献降低34.38%,而矿物沉淀作用贡献增加了38.09%;在热解含氧量增加至6%时,离子交换作用的贡献从34.47%增加到56.20%;矿物质吸附贡献包括阳离子交换和沉淀,占81.38%~85.99%,是玉米秸秆生物炭的主要吸附机理,其次是络合反应和π电子配位作用.Corn stalks were selected as raw materials and pyrolyzed in a fluidized bed reactor to obtain biochars at different pyrolysis temperatures and different low-oxygen atmospheres.The physical and chemical properties of biochar and the Pb^(2+)adsorption performance were studied,and the qualitative and quantitative analysis of the adsorption mechanism was conducted.Experimental results show that the adsorption of Pb^(2+)by the corn stalk biochars reaches equilibrium after 12 h.The adsorption process can be preferably described by the Langmuir model and the Pseudo-second-order model,indicating that the adsorption occurs on the homogenous surface and acts as monolayer adsorption,and the adsorption process is mainly subject to chemisorption.At higher pyrolysis temperatures,the adsorption contribution of metal ion exchange and functional group complexation is decreased by 34.38%,while the contribution of precipitation is increased by 38.09%.When the oxygen content of pyrolysis is increased to 6%,the contribution of metal ion exchange is increased from 34.47%to 56.20%.The contributions of mineral adsorption includ metal ion exchange and precipitation,accounting for 81.38%to 85.99%.It is the dominating adsorption mechanism of corn stalk biochar,followed by complexation and coordination withπelectrons.

关 键 词：生物质 流化床 吸附 废水 铅 定量分析 

分 类 号：X52[环境科学与工程—环境工程]