膨化预处理提升软木生物炭的染料吸附性能及其作用机制  

Expansion pretreatment enhancing dye adsorption performance of cork biochar and its mechanism

作　　者：李承禹 方佳颖 王启航 曾令顺 母军[1] Li Chengyu;Fang Jiaying;Wang Qihang;Zeng Lingshun;Mu Jun(Key Laboratory of Wooden Material Science and Application of Ministry of Education,School of Materials Science and Technology,Beijing Forestry University,Beijing 100083,China;Center for Water and Ecology,Tsinghua University,State Key Joint Laboratory of Environment Simulation and Pollution Control,School of Environment,Tsinghua University,Beijing 100084,China)

机构地区：[1]木质材料科学与应用教育部重点实验室,北京林业大学材料科学与技术学院,北京100083 [2]清华大学环境学院环境模拟与污染控制国家重点联合实验室,北京100084

出　　处：《北京林业大学学报》2025年第2期163-174,共12页Journal of Beijing Forestry University

基　　金：国家自然科学基金项目(32371794);国家资助博士后研究人员计划(GZB20240367)。

摘　　要：【目的】生物炭在处理染料废水方面具有巨大的应用潜力。为制备具有高效染料吸附性能的吸附剂,同时提升生物质资源的综合利用,采用膨化预处理软木制备生物炭。【方法】采用水煮法和微波法对软木进行膨化预处理,然后置于管式炉内550℃热解60 min得到软木生物炭,利用SEM、FTIR和BET分析软木生物炭的微观结构和化学特性,通过批量吸附实验研究软木生物炭对亚甲基蓝(MB)和刚果红(CR)两种阴阳离子染料的吸附性能,并联合动力学、等温线、热力学模型拟合以及结构表征解析吸附机理。【结果】微波膨化预处理得到的软木生物炭(MBC-90)表现出更加粗糙的表面和丰富的微孔和介孔,同时伴随着—OH官能团的减少和芳香性结构的增强,这使得MBC-90更适合吸附小分子染料MB;而水煮膨化预处理得到的软木生物炭(WBC-90)具有更大的孔隙和不规则的孔壁结构,并保留了更多的—OH官能团,这使得WBC-90更适合吸附大分子染料CR。MBC-90对MB的最大吸附容量达到193.63 mg/g,WBC-90对CR的最大吸附容量达到203.55 mg/g,均优于未膨化软木生物炭对MB(129.18 mg/g)和CR(121.44 mg/g)的最大吸附容量。MBC-90对MB和WBC-90对CR的吸附表现出优异的pH适应性,在pH为2~10的范围内保持较高的吸附容量。在经过5次吸附-脱附实验后,MBC-90对MB(95.43 mg/g)和WBC-90对CR(138.17 mg/g)仍具有良好的吸附稳定性和再生性能。吸附过程符合准一级动力学模型和Langmuir等温线模型,表明吸附过程以物理吸附为主导,并在生物炭表面形成单分子层覆盖。热力学分析进一步证实了吸附过程为自发进行的吸热反应,且膨化处理显著提高了吸附的自发性。综合分析表明,软木生物炭对染料分子的吸附机理涉及多重作用力,包括静电引力、氢键相互作用、π-π堆积效应以及孔隙填充。【结论】本研究通过微波和水煮膨化预处理提升了软木生物�[Objective] Biochar demonstrates significant potential for dye wastewater treatment.To prepare adsorbent with high dye adsorption performance and enhance the comprehensive utilization of biomass resources,biochar was prepared by expansion pretreatment of cork.[Method] Cork was subjected to expansion pretreatment using water-boiling and microwave methods,followed by pyrolysis in a tubular furnace at 550 ℃ for 60 min to produce cork biochar.The microstructure and chemical properties of cork biochar were characterized using SEM,FTIR,and BET analyses.Batch adsorption experiments were conducted to evaluate the adsorption performance of cork biochar for methylene blue(MB) and Congo red(CR),two cationic and anionic dyes.The adsorption mechanisms were elucidated through kinetic,isotherm,and thermodynamic model fitting,combined with structural characterization.[Result] The cork biochar obtained through microwave expansion pretreatment(MBC-90) exhibited a rougher surface with abundant micropores and mesopores,alongside a reduction in —OH functional groups and an enhancement of aromatic structures.These characteristics made MBC-90 more suitable for adsorbing small dye molecules MB.In contrast,the cork biochar produced via water-boiling expansion pretreatment(WBC-90) displayed larger pores and irregular pore wall structures,while retaining more —OH functional groups,making it better suited for adsorbing larger dye molecules CR.The maximum adsorption capacity of MBC-90 for MB reached 193.63 mg/g and that of WBC-90 for CR reached 203.55 mg/g,which were better than the maximum adsorption capacity of unexpanded cork biochar for MB(129.18 mg/g) and CR(121.44 mg/g).The adsorption of MBC-90 on MB and WBC-90 on CR showed excellent pH adaptability,maintaining high adsorption capacity in pH range of 2-10.After five adsorption-desorption experiments,the adsorption stability and regeneration performance of MBC-90 on MB(95.43 mg/g) and WBC-90 on CR(138.17 mg/g)remained good.The adsorption process followed a pseudo-first-order kinet

关 键 词：废水处理 染料 吸附剂 软木生物炭 膨化预处理 动力学 吸附等温线 

分 类 号：TQ424.3[化学工程]