氧化镁掺杂改性活性炭的制备及其对彩板印刷VOCs废气的吸附性能及机理  

Preparation of magnesium oxide doped modified activated carbon and its adsorption properties and mechanism toward color plates printing VOCs

作　　者：寇永康 党小庆[1,2] 曹利 屈嘉鑫[1,2] 任一彤 董静 KOU Yongkang;DANG Xiaoqing;CAO Li;QU Jiaxin;REN Yitong;DONG Jing(School of Environmental and Municipal Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Shaanxi Provincial Key Laboratory of Environmental Engineering,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学环境与市政工程学院,西安710055 [2]陕西省环境工程重点实验室,西安710055

出　　处：《环境工程学报》2024年第6期1559-1569,共11页Chinese Journal of Environmental Engineering

基　　金：国家重点研发计划(2017YFC0212204);陕西省重点研发计划(2018ZDCXL-SF-02-04,2024SF-YBXM-569)。

摘　　要：针对实际工业应用中活性炭吸附VOCs存在的竞争吸附导致吸附量减少的问题,以彩板印刷过程产生的甲苯、乙酸乙酯、异丙醇为代表,采用浸渍法对煤基活性炭进行掺杂氧化镁改性,提高活性炭在实际应用中多组分吸附体系的吸附容量。结果表明,氧化镁的最佳掺杂比和焙烧温度分别为1%和450℃,相比原始活性炭,AC/MgO-1%在单组分吸附实验中对甲苯、乙酸乙酯、异丙醇的吸附容量分别提高了42%、18%、25%,在二元吸附实验中,弱吸附质在AC/MgO-1%的被取代量由51%、55%、38%下降至24%、44%、33%,二元竞争作用减弱,吸附容量提高34%~80%;经五次吸脱附循环实验后,AC/MgO-1%的吸附容量仍维持在92.68%以上。DFT计算结果表明,甲苯、乙酸乙酯、异丙醇在AC上吸附的过程中,甲苯为强吸附质,在氧化镁上吸附时异丙醇为强吸附质,氧化镁掺杂可在一定程度上减少二元竞争作用;SEM、BET、FTIR及XRD表征结果表明,掺杂氧化镁虽会减少比表面积,但会增加其极性官能团和活性位点,提高吸附容量。Aiming at the adsorption capacity reduction of VOCs on activated carbon due to the competitive adsorption in industrial applications,coal-based activated carbon was modified with magnesium oxide doped by impregnation to improve the adsorption capacity for multicomponent adsorption,taking toluene,ethyl acetate,and isopropanol as the representatives of VOCs in color plates printing.The results showed that the optimal doping ratio and calcination temperature of magnesium oxide were 1%and 450℃,respectively.Compared with the original activated carbon,the adsorption capacity of modified activated carbon to toluene,ethyl acetate and isopropanol in single-component adsorption experiments increased by 42%,18%and 25%,respectively,the substitution amount of weak adsorbates in the binary adsorption experiments decreased from 51%,55%and 38%to 24%,44%and 33%,respectively,and the adsorption capacity increased by 34%~80%,indicating that the binary competition was weakened.The adsorption capacity of AC/MgO-1%remained above 92.68%after five regeneration cycles.DFT calculations showed that the adsorption process of toluene,ethyl acetate,and isopropanol,toluene was a type of strong adsorbate adsorbed on AC,while on magnesium oxide,isopropanol was a type of strong adsorbate,and magnesium oxide doping could reduce the binary competition effect to a certain extent.SEM,BET,FTIR,and XRD characterization results indicated that doping of magnesium oxide decreased the specific surface area,but it increased the polar functional groups and active sites,and improved the adsorption capacity.

关 键 词：活性炭 改性 吸附 VOCS DFT 

分 类 号：X703[环境科学与工程—环境工程]