摘要
废弃生物质的再利用对减污降碳有较大意义.本文采用垂序商陆的茎为原料,经高锰酸钾溶液浸泡后,氮气保护下分别于700、850℃焙烧得到锰改性生物炭(Mn-700BC、Mn-850BC),并以同温度下未改性的生物炭(700BC、850BC)作为参照,探讨改性材料活化过二硫酸盐(PDS)降解苯酚的性能.SEM-EDS、XRD和XPS的结果表明,锰氧化物成功负载于生物炭上,锰的价态为Mn(Ⅱ)、Mn(Ⅲ)和Mn(Ⅳ)的混合价;850℃焙烧所得生物炭的石墨化程度、孔容及比表面积比700℃的生物炭高,官能团含量低.Mn-700BC和Mn-850BC对苯酚的去除率可达到89%和91%,且负载的锰氧化物对苯酚的降解起主要活化作用,碳的石墨化结构对活化有一定作用;EPR和自由基捕获实验结果显示,锰改性生物炭活化PDS降解苯酚以自由基氧化路径为主,同时伴有非自由基氧化途径.苯酚和PDS初始浓度对催化反应初活性的影响可以用Langmuir-Hinshelwood模型描述,降解反应速率受苯酚及PDS的吸附控制.在初始pH 3—9范围内,提高pH有利于苯酚的降解;共存的Cl^(−)、NO_(3)^(−)、SO_(4)^(2-)对苯酚降解均有一定抑制作用.锰改性生物炭活化PDS降解苯酚效果优良,揭示了这种改性材料用于活化过硫酸盐处理水中有机物的潜在前景.
The reuse of biomass waste is helpful for pollution and carbon dioxide emissions.In this study,the stem of phytolacca americana L was chosen as the biomass,which was then soaked in potassium permanganate solution and calcined under N2 atmosphere at 700 ℃ or 850 ℃.The obtained Mn-modified biochars(Mn-700BC and Mn-850BC)and the unmodified biochars(700BC and 850BC)as their references were used to evaluate their catalytic peroxydisulfate(PDS)activation performances for phenol degradation.The SEM-EDS,XRD and XPS results unveil that manganese oxides,mainly Mn(Ⅱ),Mn(Ⅲ)and Mn(Ⅳ),were loaded on the biochars successfully.The biochars prepared at 850 ℃ possess higher graphitization extent,bigger pore volume and larger specific surface area compared with those at 700 ℃.However,the former materials have functional groups than the latter.Mn-700BC and Mn-850BC exhibited high phenol removal efficiencies of 89%and 91%,respectively.The loaded manganese oxides played a major role in the activation of phenol degradation,while the graphitic structure of carbon also played a certain role.Based on the results of radical tapping experiments and EPR spectra,the radical reaction pathway is the main mechanism,while the nonradical process is included for phenol degradation,too.The relationships between the initial concentration of phenol or PDS and the catalytic activity can be well described by Langmuir-Hinshelwood model,indicating that the adsorption of phenol or PDS is the rate-controlling step during PDS activation by Mn-modified biochars for phenol degradation.Increasing pH can enhance phenol degradation with pH ranging from 3 to 9.The coexistence of Cl^(−)、NO_(3)^(−) and SO_(4)^(2-)is harmful to phenol degradation.Its excellent catalytic performance of PDS activation for phenol degradation reveals that these Mn-modified biochars have a good potential prospect in activating PDS for aqueous organic pollutants removal.
作者
刘晨曦
王晓波
刘凤玲
刘杰
郭照冰
仇鹏翔
杨圆圆
LIU Chenxi;WANG Xiaobo;LIU Fengling;LIU Jie;GUO Zhaobing;QIU Pengxiang;YANG Yuanyuan(School of Environmental Science and Engineering,Nanjing University of Information Science and Technology,Nanjing,210044,China;Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technologies,Nanjing,210044,China;Peking University Shenzhen Graduate School,School of Environment and Energy,Shenzhen,518055,China;Guangdong Nantian Institute of Forensic Science,Shenzhen,518016,China)
出处
《环境化学》
CAS
CSCD
北大核心
2024年第6期1954-1965,共12页
Environmental Chemistry
基金
国家自然科学基金(51608277)资助.
关键词
锰改性
生物炭
过硫酸盐
活化
manganese modification
biochar
persulfate
activation
作者简介
通信联系人:刘凤玲,E-mail:liufl@nuist.edu.cn。
