摘要
为探索农林废弃物的资源化利用途径及对水体中重金属的处理应用,以花生壳和玉米芯为原料,于600℃下热解制备生物炭,就两种生物炭对Pb^(2+)的吸附性能进行研究,利用等温吸附模型和吸附动力学模型研究了花生壳和玉米芯生物炭对Pb^(2+)的吸附行为,分析了花生壳生物炭和玉米芯生物炭对Pb^(2+)的吸附特性差异及其影响因素。同时,结合FTIR红外表征了生物炭吸附前后官能团的变化,探讨了两种生物炭吸附Pb^(2+)的机制。结果表明:1)花生壳生物炭和玉米芯生物炭吸附Pb^(2+)分别在480和360 min达到吸附平衡,理论最大吸附量分别为20.85、28.51 mg/g;2)Langmuir-Freundlich模型能够很好地描述两种生物炭对Pb^(2+)的等温吸附规律,表明吸附过程包括单分子层和多分子层的多相吸附;花生壳生物炭和玉米芯生物炭对Pb^(2+)的吸附动力学均符合二级动力学模型,表明其对Pb^(2+)的吸附主要是以化学吸附为主,Pb^(2+)与花生壳生物炭和玉米芯生物炭之间的表面吸附和颗粒内扩散是主要影响因素;3)吸附机制主要是阳离子-π键和络合作用。
In order to explore the resource utilization of agricultural and forestry wastes and the treatment of heavy metals in water,in this experiment,peanut shell and corncob granules were used as raw materials to prepare biochar by pyrolysis at 600℃.The adsorption performance of the two biochar on Pb^(2+)was studied.The adsorption behavior of peanut shell and corn cob biochar on Pb^(2+)was studied by isothermal adsorption model and adsorption kinetic model.The difference of Pb^(2+)adsorption characteristics between peanut shell biochar and corncob biochar and its influencing factors were analyzed.At the same time,FTIR infrared spectroscopy was used to characterize the changes of functional groups before and after biochar adsorption,and the adsorption mechanism of Pb^(2+)by the two biochar was discussed.The results showed that:1)The adsorption equilibrium of Pb^(2+)by peanut shell biochar and corncob biochar was reached at 480 and 360 min,respectively,and the theoretical maximum adsorption capacities were 20.85 and 28.51 mg/g,respectively;2)The Langmuir-Freundlich model can well describe the isothermal adsorption of Pb^(2+)by two biochar species,indicating that the adsorption process includes the multiphase adsorption of monolayer and multilayer.The adsorption kinetics of Pb^(2+)by peanut shell biochar and corncob biochar were consistent with the Pseudo second-order kinetic model,indicating that the adsorption of Pb^(2+)on peanut shell biochar and corncob biochar was mainly chemisorption,and the surface adsorption and intra particle diffusion between Pb^(2+)and peanut shell biochar and corn cob biochar were the main influencing factors,3)The adsorption mechanism mainly includes cationic-πbond and complexation.
作者
石晓磊
安焱
王章鸿
杨成
王雅洁
范百龄
SHI Xiaolei;AN Yan;WANG Zhanghong;YANG Cheng;WANG Yajie;FAN Bailing(College of Ecological and Environmental Engineering,Guizhou Minzu University,Guiyang 550025,China)
出处
《有色金属工程》
CAS
北大核心
2023年第4期127-135,共9页
Nonferrous Metals Engineering
基金
国家自然科学基金资助项目(52260018)。
关键词
生物炭
花生壳
玉米芯
吸附特性
铅
biochar
peanut shel
corncob granules
adsorption characteristics
lead
作者简介
石晓磊(1997-),男,硕士研究生,主要从事固体废弃物资源化利用及矿区污染治理修复;通信作者:范百龄(1986-),男,博士,副教授,主要从事表生环境物质循环及生态环境效应。
