摘要
硝基苯是水中广泛存在的污染物,生物炭是一种很有前途的去除有机污染物的材料,但其吸附能力较低。改性可以用于改善其吸附性能,但关于改性生物炭吸附硝基苯的研究较少。为了研究改性生物炭对硝基苯吸附的影响,文章制备了不同温度下的小麦秸秆生物炭,通过KOH改性处理,分析了改性对生物炭结构和形貌的影响,研究了KOH改性对生物炭吸附硝基苯的影响,采用等温吸附模型、吸附-分配双模型等方法,探讨了改性对生物炭吸附硝基苯作用机制的影响。结果表明,改性提高了500℃和700℃生物炭的比表面积和微孔面积,降低了介孔面积。改性降低了300℃生物炭的芳香性,提高了500℃和700℃生物炭的芳香性。生物炭对硝基苯的等温吸附拟合Freundlich好于Langmuir模型,改性降低了300℃生物炭的吸附性能,提高了500℃和700℃生物炭的吸附性能,其中BC-700-KOH吸附性能最好。吸附-分配模型拟合结果表明,300℃生物炭以分配为主,改性抑制了生物炭的表面吸附能力。500℃和700℃生物炭以表面吸附为主,改性提高了生物炭的表面吸附能力。改性通过提高500℃和700℃生物炭的芳香化程度,增加比表面积和微孔面积,增强表面吸附作用,促进生物炭对硝基苯的吸附。
Nitrobenzene is a widespread contaminant in water.Biochar(BC)is a promising material for removing organic pollutants,but the adsorption capacity of pristine BC is low.Chemical modification is often used to improve the adsorption performance,but information on the sorption of nitrobenzene by modified BC is rare.To explore the effect of modified biochar on nitrobenzene adsorption,wheat straw biochar was prepared with different pyrolysis temperatures,and modified by KOH.The effect of modification on the structure and morphology of biochar was analyzed.The effect of modification on adsorption of biochar for nitrobenzene in water was investigated.The effect of modification on the adsorption mechanism of nitrobenzene by biochar was discussed via isothermal adsorption model and Dual-model.The results showed that modification could increase specific surface area and microporous area of BC-500 and BC-700,decrease the mesoporous area.Modification decreased the aromatization of BC-300,while increased the aromatization of BC-500 and BC-700.The adsorption isotherms of naphthalene by biochar were better fitted by Freundlich model,modification inhibited the sorption ability of BC-300,while prompted the sorption ability of BC-500 and BC-700.Dual-model results showed that partitioning was the dominant mechanism of nitrobenzene sorption on BC-300,modification inhibited the adsorption ability of BC-300.The adsorption was the dominant mechanism of nitrobenzene sorption on BC-500 and BC-700.Modification increased the adsorption ability of BC-500 and BC-700,probably due to the increase in aromatization,specific surface area and microporous area,resulting in enhancement of adsorption of BC-500 and BC-700.
作者
陆海楠
LU Hainan(Shanghai Academy of Environmental Science,Shanghai 200233,China;State Environmental Protection Engineering Center for Urban Soil Contamination Control and Remediation;School of Environmental Science and Engineering,Shanghai Jiaotong University,Shanghai 200240,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2022年第7期169-176,共8页
Environmental Science & Technology
基金
上海市科技人才计划(19XD1434900)
上海市“超级博士后”计划(2019152)。
关键词
生物炭
硝基苯
改性
吸附
分配
biochar
nitrobenzene
modification
adsorption
partition
