7-ACA发酵药渣生物炭对水体中Pb(Ⅱ)和Cd(Ⅱ)的吸附特性  

Adsorption Characteristics of Pb(Ⅱ)and Cd(Ⅱ)in Water Bodies onto Biochars Derived from 7-ACA Fermented Residue

作　　者：张威[1,2] 陈志 韩占涛 王平 王妍妍[1,2] 马丽莎[1,2] 李红超[3] 孔祥科 ZHANG Wei;CHEN Zhi;HAN Zhantao;WANG Ping;WANG Yanyan;MA Lisha;LI Hongchao;KONG Xiangke(Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang 050061,China;Key Laboratory of Groundijuater Contamination and Remediation of Hebei Province,China Geological Survey,Shijiazhuang 050061,China;Hebei Geo-Environmenrt Monitoring,Shijiazhuang 050021,China;Technical Centre for Soil,Agriculture and Rural Ecology and Environment,Ministry of Ecology and Environment,Beijing 100012,China)

机构地区：[1]中国地质科学院水文地质环境地质研究所,河北石家庄050061 [2]中国地质调查局/河北省地下水污染机理与修复重点实验室,河北石家庄050061 [3]河北省地质环境监测院,河北石家庄050021 [4]生态环境部土壤与农业农村生态环境监管技术中心,北京100012

出　　处：《安全与环境工程》2022年第6期208-216,共9页Safety and Environmental Engineering

基　　金：国家重点研发计划项目子课题(2019YFC1805303);国家自然科学基金面上项目(4207071759)。

摘　　要：以7-氨基头孢烷酸(7-ACA)发酵药渣为原材料,采用限氧热解法在不同热解温度(300℃、500℃、700℃)条件下制备了7-ACA发酵药渣生物炭(简称药渣生物炭),在利用扫描电镜、比表面积分析、X射线衍射和红外光谱对反应前后的药渣生物炭进行物理化学性质表征基础上,通过吸附动力学和平衡吸附试验,探究了该药渣生物炭对水体中重金属Pb(Ⅱ)和Cd(Ⅱ)的吸附特征与机理。结果表明:(1)随着热解温度的升高,所制备的药渣生物炭表面官能团不断减少,芳香化程度增加,比表面积增大,对水体中Pb(Ⅱ)和Cd(Ⅱ)平衡吸附量和吸附速率也随之增加;(2)药渣生物炭对水体中Pb(Ⅱ)和Cd(Ⅱ)的吸附动力学均符合Lagergren准二级动力学方程,具有快速吸附、缓慢平衡的特点,吸附速率主要受化学作用控制;(3)Langmuir模型能很好地描述药渣生物炭对水体中Pb(Ⅱ)和Cd(Ⅱ)的等温吸附过程,吸附特征近似单分子层吸附,药渣生物炭对水体中Pb(Ⅱ)和Cd(Ⅱ)的最大吸附量分别达到434.78 mg/g和181.81 mg/g;(4)药渣生物炭对水体中Pb(Ⅱ)和Cd(Ⅱ)的吸附机理主要包括沉淀作用、络合作用、离子交换作用和阳离子-π键作用。In order to solve the problem of heavy metal-contaminated wastewater and find a novel application for antibiotic medicine residues,the 7-ACA fermented residues(abbreviated as residue biochar)are selected as the raw materials to prepare the biochars using the oxygen-limited pyrolysis method at different tempe-ratures(300℃,500℃,700℃).The scanning electron microscope(SEM),specific surface area analysis(BET),X-ray diffraction(XRD)and flourier transform infrared spectrum(FTIR)techniques are used to characterize the physicochemical properties of the biochars before and after reaction.The adsorption mechanisms of Pb(Ⅱ)and Cd(Ⅱ)in water bodies onto biochars are investigated by adsorption kinetics experiment and equilibrium adsorption experiment.The results show that the functional groups of the biochars decrease with an increase in pyrolysis temperature,while the aromatization and BET values of the biochars increase with pyrolysis temperature rise.The equilibrium adsorption capacity and adsorption rate of Pb(Ⅱ)and Cd(Ⅱ)in water bodies both increase with increasing pyrolysis temperature.The adsorption process can be characterized by rapid absorption and slow balance.The adsorption kinetics of Pb(Ⅱ)and Cd(Ⅱ)in water bodies fit better with the pseudo-second-order model,indicating that the chemical sorption might be rate-limiting in the sorption of Pb(Ⅱ)and Cd(Ⅱ)in water bodies by the biochars.The Pb(Ⅱ)and Cd(Ⅱ)in water bodies isotherm adsorption data are well fitted with the Langmuir adsorption isotherm model,and the adsorption capacity of Pb(Ⅱ)and Cd(Ⅱ)in water bodies are as high as 434.78 mg/g and 181.81 mg/g,respectively.The adsorption mechanisms of Pb(Ⅱ)and Cd(Ⅱ)by the biochars are syste-matically described as follows:(1)forming a precipitate with CO;(2)complexation;(3)Ion exchange;(4)Pb-πand Cd-πmetal bonding interaction.

关 键 词：7-ACA发酵药渣 生物炭 重金属 Pb(Ⅱ)和Cd(Ⅱ) 热解温度 吸附机理 

分 类 号：X703[环境科学与工程—环境工程] X787