巯基改性褐煤的制备及其对Fe^(2+)、Mn^(2+)的吸附特性研究  

Preparation of mercapto modified lignite and its adsorption characteristics for Fe^(2+),Mn^(2+)

作　　者：狄军贞[1] 曹洋 赵文琦 DI Junzhen;CAO Yang;ZHAO Wenqi(School of Civil Engineering,Liaoning Technical University,Fuxin 123000,China)

机构地区：[1]辽宁工程技术大学土木工程学院,辽宁阜新123000

出　　处：《煤炭科学技术》2023年第3期261-270,共10页Coal Science and Technology

基　　金：国家自然科学基金资助项目(41672247,41102157);辽宁省“兴辽英才”青年拔尖人才计划资助项目(XLYC1807159);。

摘　　要：针对酸性矿山废水中Fe^(2+)、Mn^(2+)含量高,褐煤吸附能力有限等问题,以褐煤为基料,选取硅烷偶联剂3-巯基丙基三甲氧基硅烷(MPTMS)作为改性试剂对褐煤进行改性处理。通过单因素试验单独考察各影响因子变化对响应值的影响,应用响应面法(RSM)进一步确定了各影响因子的交互作用,利用EDS能谱、扫描电镜(SEM)、傅立叶变换红外吸收光谱仪(FTIR)等手段对复合材料进行了表征。结果表明,单因素试验确定巯基改性褐煤较优制备条件为褐煤粒径0.18 mm(80目)、褐煤与甲醇质量比为1∶3、反应温度40℃。利用Design-Expert软件进行优化配比,综合考虑去除率与成本后,提出本试验巯基改性褐煤的最佳配比为:褐煤粒径0.18 mm(80目),褐煤与甲醇质量比为1∶4,反应温度为40℃,其Fe^(2+)、Mn^(2+)去除率分别为84.2%、88.9%,饱和吸附容量分别为6.715、2.295 mg/g,较原褐煤Mn^(2+)去除率提升44.9%,Fe^(2+)吸附容量提高27.42%,Mn^(2+)吸附容量提高29.01%。改性褐煤吸附Fe^(2+)、Mn^(2+)的等温吸附线均符合Langmuir模型,吸附符合单分子层吸附过程。由表征结果可知,褐煤经巯基改性后表面结构遭到破坏,出现大量孔道结构,极大增加了比表面积;同时,MPYMS分子结构中含有硅氧基和巯基,硅氧基易与含有巯基的载体物质发生水解反应,形成—C—Si—O—键,从而将巯基接枝到载体物质表面,且重金属离子与吸附剂表面集团的结合可能会促进其骨架变形或断裂,生成碎片分子,暴露更多的羟基,增加吸附点位,提高褐煤吸附能力。In order to solve the problems of high Fe^(2+)and Mn^(2+)content and limited adsorption capacity of lignite in acid mine wastewater(AMD),lignite was selected as the base material and silane coupling agent 3-mercaptopropyl trimethoxy silane(MPTMS)was selected as the modification reagent to modify the lignite.The influence of the change of each influencing factor on the response value was investigated by single factor test.and the interaction of each influence factor was further determined by response surface methodology(RSM).The composites were characterized by energy dispersive spectroscopy(EDS),scanning electron microscopy(SEM)and Fourier transform infrared absorption spectrometer(FTIR).The results show that the optimal preparation conditions of sulfhydryl modified lignite were determined by single factor test as follows:lignite particle size 0.18 mm(80 mesh),mass ratio of lignite to methanol 1∶3,reaction temperature of 40℃.The Design-Expert software is used to optimize the ratio,after comprehensively considering the removal rate and cost,the optimal ratio of mercapto-modified lignite in this experiment is proposed as follows:the particle size of lignite is 0.18 mm(80 mesh),the mass ratio of lignite to methanol is 1∶4,and the reaction temperature is 40℃,the Fe^(2+)and Mn^(2+)removal rates are 84.2%and 88.9%,respectively.The saturated adsorption capacity is 6.715mg/g and 2.295 mg/g,respectively.Compared with the original lignite,the Mn^(2+)removal rate,Fe^(2+)adsorption capacity and Mn^(2+)adsorption capacity increase by 44.9%,27.42%and 29.01%,respectively.The isothermal adsorption lines of Fe^(2+)and Mn^(2+)adsorbed by modified lignite all conform to Langmuir model,and the adsorption conforms to monolayer adsorption process.It can be seen from the characterization results that the surface structure of lignite after modification with sulfhydryl group is destroyed and a large number of pore structures appear,and the specific surface area is greatly increased.At the same time,the molecular structure of MPYM

关 键 词：酸性矿山废水 褐煤 巯基改性 响应曲面法 离子吸附 能量色散X-射线光谱(EDS) 扫描电子显微镜(SEM) 傅里叶变换红外光谱(FTIR) 

分 类 号：X703[环境科学与工程—环境工程]