海绵负载锰氧化物/氮掺杂碳纳米纤维对亚甲基蓝的吸附-催化协同去除性能与机理  

Performance and mechanism of adsorption-catalytic cooperative removal of methylene blue by sponge supported manganese oxide/nitrogen doped carbon nanofibers

作　　者：李语炎 吴连永 贾志刚[1,2] 未冉 王浩宇 LI Yuyan;WU Lianyong;JIA Zhigang;WEI Ran;WANG Haoyu(Engineering Research Center of Biofilm Water Purification and Utilization Technology of Ministry of Education,Anhui University of Technology,Ma’anshan 243002;School of Chemistry and Chemical Engineering,Anhui University of Technology,Ma’anshan 243002)

机构地区：[1]安徽工业大学生物膜法水质净化及利用技术教育部工程研究中心,马鞍山243002 [2]安徽工业大学化学与化工学院,马鞍山243002

出　　处：《环境科学学报》2024年第11期123-135,共13页Acta Scientiae Circumstantiae

基　　金：生物膜法水质净化及利用技术教育部工程研究中心开放课题(No.22378417);国家自然科学基金(No.20907001)。

摘　　要：首先采用水热-煅烧法制备了锰氧化物/氮掺杂碳纳米纤维粉体催化剂(MnO_(x)/C),随后以三维多孔结构的三聚氰胺海绵(MS)为载体,聚乙烯醇(PVA)为粘合剂,将MnO_(x)/C粉体锚固于多孔MS框架结构上,制得三维块体状催化材料(MnO_(x)/C-700/PVA@MS).通过X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)等手段对产物结构进行了表征和分析.以亚甲基蓝(MB)溶液为模拟染料废水,评估了MnO_(x)/C-700/PVA@MS对亚甲基蓝的去除性能.结果表明:制备的MnO_(x)/C-700/PVA@MS对亚甲基蓝具有良好的吸附-催化协同去除效应.对MB的吸附过程符合准二级吸附动力学模型.等温吸附过程属于单分子层(Langmuir)吸附,最大吸附容量为4.93 mg·g^(-1).在pH为7、催化剂用量为0.2 g·L^(-1)、过一硫酸盐(PMS)添加量为10 mg的条件下,50 mL的10 mg·L^(-1)亚甲基蓝溶液15 min内降解率达99.6%.电子顺磁共振(EPR)证实反应体系中有SO_(4)^(•–)、•OH、•O_(2)-、^(1)O_(2)等多种活性自由基产生,淬灭实验表明非自由基途径在降解体系中占据主导地位,同时介导的电子转移途径参与了MB降解过程.Manganese oxide/nitrogen doped carbon nanofiber powder catalysts(MnO_(x)/C)were synthesized by hydrothermal-calcination method.Subsequently,a three-dimensional porous melamine sponge(MS)was employed as a carrier,with polyvinyl alcohol(PVA)as a binder to anchor the MnO_(x)/C powder onto the porous MS framework,resulting in a three-dimensional block-shaped catalytic material(MnO_(x)/C-700/PVA@MS).The structure of the product was characterized and analyzed using X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and Fourier transform infrared spectroscopy(FTIR).The removal performance of MnO_(x)/C-700/PVA@MS for methylene blue(MB)was evaluated in simulated dye wastewater.The results show that the prepared MnO_(x)/C-700/PVA@MS exhibits good synergistic adsorption-catalytic removal for MB.The adsorption kinetics of MB follows a pseudo-second-order adsorption model.The isothermal adsorption process belongs to monolayer(Langmuir)adsorption,with a maximum adsorption capacity of 4.93 mg·g^(-1).Under conditions of pH 7,catalyst dosage of 0.2 mg·L^(-1),and peroxydisulfate(PMS)addition of 10 mg,the degradation rate of a 10 mg·L^(-1)MB solution(50 mL)reaches 99.6%within 15 minutes.Electron paramagnetic resonance(EPR)confirms the generation of various reactive free radicals such as SO_(4)^(•–),•OH,•O_(2)-and ^(1)O_(2)in the reaction system.Results of Quenching experiments indicate that the non-radical pathway predominates in the degradation system,while the mediated electron transfer pathway also contributes in the MB degradation process.

关 键 词：锰氧化物 氮掺杂碳纤维 亚甲基蓝 吸附 催化降解 

分 类 号：X703[环境科学与工程—环境工程]