摘要
以赤泥(RM)为原料,采用酸碱预处理方法制备了介孔赤泥材料(MRM),并以其为载体,利用浸渍法负载MgO以期增加碱性活性位点,通过BET,XRF,XRD,CO_(2)-TPD等手段对其结构和组成成分进行表征分析.研究表明,MRM的比表面积较RM提高了约28倍,孔结构丰富,物相组成分析表明以赤铁矿为主.负载MgO后,孔结构被堵塞,其比表面积和孔容随着Mg负载量的增加而减小,对5%MgO/MRM吸附剂通过XRD检测结果未发现MgO,表明Mg在吸附剂中分散性较好.当吸附温度为30℃,酸碱预处理赤泥的CO_(2)吸附容量为1.54mg/g,而5%MgO/MRM的吸附容量为2.26mg/g,说明负载MgO后,碱性活性位点数量明显增加,化学吸附作用增强,随着温度的升高,吸附容量逐渐降低.CO_(2)-TPD测试结果表明,MRM和5%MgO/MRM均以化学吸附为主,主要形成碳酸盐和碳酸氢盐结构.
Mesoporous modified red mud adsorbent(MRM)was prepared via acid digestion and alkali reprecipitation,red mud(RM)was used as raw material in our experiment.MgO was loaded on the MRM as the support by impregnation method in order to increase the alkaline active site.The structural properties and the composition of samples were characterized and analyzed by BET,XRF,XRD,CO_(2)-TPD.The results showed that the specific surface area of the MRM was about 28 times higher than the RM,the pore structure was rich,and hematite was the dominant mineral phase composition in MRM.It could be seen that the specific surface area and the pore volume decreased with the increase of the Mg loading,which was due to the occupation and the blockage of the pore structure of the MRM support by MgO.The XRD test results of 5%MgO/MRM did not show the peak shape of MgO,maybe because the loading was small or Mg dispersed on the pore channels of the MRM.When the adsorption temperature was 30℃,the CO_(2)adsorption capacity of the MRM was 1.54mg/g,the adsorption capacity of 5%MgO/MRM was 2.26mg/g,which indicated that the number of alkaline active sites increased significantly after MgO loading,and the chemical adsorption effect enhanced.With the increase of the temperature,the adsorption capacity gradually decreased.The results of the CO_(2)-TPD test showed that both MRM and 5%MgO/MRM were dominated by chemisorption,which formed the carbonate and bicarbonate structures.
作者
梁文俊
杨岚
张艳
方宏萍
刘佳
LIANG Wen-jun;YANG Lan;ZHANG Yan;FANG Hong-ping;LIU Jia(Key Laboratory of Beijing on Regional Air Pollution Control,Beijing University of Technology,Beijing 100124,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第6期2798-2805,共8页
China Environmental Science
