改性风化煤铅修复剂的制备及其吸附机制  

Preparation and adsorption mechanism of modified weathered coal lead remediating agent

作　　者：焦子乐 李林 陈潇晶 卢晋晶 郜春花 徐明岗 李建华 Jiao Zile;Li Lin;Chen Xiaojing;Lu Jinjing;Gao Chunhua;Xu Minggang;Li Jianhua(College of Resources and Environment,Shanxi Agricultural University,Taiyuan 030031,China;Shanxi Province Key Laboratory of Soil Environment and Nutrient Resources,Taiyuan 030031,China;Institute of Loess Plateau,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西农业大学资源与环境学院,山西太原030031 [2]土壤环境与养分资源山西省重点实验室,山西太原030031 [3]山西大学黄土高原研究所,山西太原030006

出　　处：《山西农业大学学报（自然科学版）》2024年第2期99-109,共11页Journal of Shanxi Agricultural University(Natural Science Edition)

基　　金：国家重点研发项目(2020YFC1806504-03);山西省自然科学基金面上项目(202103021224137);山西省博士来晋奖励项目(SX⁃BYKY2021089);山西农大博士科研启动项目(2021BQ48,2021BQ49)。

摘　　要：[目的]风化煤来源广泛,价格低廉,且具有孔径分布合理、活性官能团丰富的特点,可通过改性提高其吸附性能,处理高浓度重金属废水,具有较大的开发价值。本文旨在以风化煤为原料制备一种高效的铅修复剂并对其吸附机制进行探究,以期为含铅废水的净化提供材料基础和理论支撑,同时为风化煤的高值化利用提供方向。[方法]采用乙烯胺改性、响应曲面法制备和优化风化煤修复剂的制备工艺,在批量吸附实验的基础上结合扫描电镜(SEM)、比表面及孔隙度分析仪(BET)、傅里叶变换红外光谱仪(FT-IR)、X射线衍射仪(XPS)等表征技术,对该材料的吸附机理进行探究。[结果]确定了三乙烯四胺改性风化煤制备铅修复剂的工艺参数:体系pH=4.98、乙烯胺用量2.58 mL·g^(-1)风化煤、超声时间为64.34 min、超声功率为350 W;该修复剂对铅的吸附过程符合拟二级动力学模型和Langmuir模型,表明该过程是以化学吸附为主的单分子层吸附,最大吸附容量达228 mg·g^(-1),较原煤提高了48%;热力学分析显示,ΔG<0、ΔH>0、ΔS>0,即该反应是自发的吸热反应,且温度升高促进反应的发生;超声改性的破坏作用和三乙烯四胺的接枝使该修复剂的介孔面积减小了63.14%、微孔面积增大了126%,同时表面丰富的羟基、羧基、羰基、酰胺基等活性基团与铅发生配位或络合反应,促进了其对铅的捕获。[结论]本研究获得了一种高效的铅修复材料,乙烯胺用量和超声温度是影响该材料吸附性能的显著因素,微孔面积增大以及丰富的活性基团(羟基、羧基、羰基、酰胺基)是其主要的铅吸附机制。[Objective]Weathered coal is widely available and inexpensive,and has the characteristics of reasonable pore size distribution and rich in active functional groups.Its adsorption performance can be improved through modification,and it can be used for treating high concentration heavy metal wastewater and thus is of great developmental value.The purpose of this paper was to prepare an efficient lead remediation agent with weathered coal as the raw material and to explore its adsorption mechanism,providing a material basis and theoretical support for the purification of lead-containing wastewater direction for the highvalue utilization of weathered coal.[Method]Vinylamine modification and response surface methods were used to prepare and optimize the preparation process of weathered coal remediation agent.The adsorption mechanism of the material was investigated using batch adsorption experiments combined with characterization techniques such as Scanning Electron Microscopy(SEM),Specific Surface and Porosity Analyzer(BET),Fourier Transform Infrared Spectroscopy(FT-IR),X-ray Diffraction(XPS).[Result]The process parameters for preparing the lead remediation agent with triethylenetetramine-modified weathered were determined:System pH=4.98,ethylene amine dosage 2.58 mL·g^(-1)weathered coal,ultrasonic time 64.34 min,ultrasonic power 350 W.The adsorption process of the remediation agent on lead was in accordance with the pseudo-second-order kinetic model and Langmuir model,indicating that the process was predominantly monolayer adsorption through chemisorption,with a maximum adsorption capacity of 228 mg·g^(-1),which was a 48%increase over the raw coal.Thermodynamic analysis showed thatΔG<0,ΔH>0,ΔS>0,indicating that the reaction was a spontaneous endothermic process,and the increase in temperature promoted the reaction.The disruption effect of ultrasonic modification and the grafting of polyethylene polyamines reduced the mesopore area by 63.14%and increased the micropore area by 126%,while the surface-rich hydroxyl

关 键 词：风化煤 乙烯胺改性 铅污染 响应曲面法 

分 类 号：X172[环境科学与工程—环境科学] X703