摘要
原始生物炭由于比表面积小、官能团含量低,吸附性能受到影响。为提高生物炭的吸附性能,以棉秆生物质为基质,采用生物质微生物发酵前处理结合低温热空气碳化(TAT)技术制备高比表面积、高含氧官能团的生物炭,并通过扫描电镜(SEM)对发酵前后棉秆生物质的形貌进行表征,采用N_(2)吸附-脱附实验、傅里叶红外变换(FT-IR)、拉曼光谱对所制备生物炭的比表面积、官能团进行分析。结果表明,微生物发酵前处理所得的棉秆生物质表面附着大量微生物,微生物的分解作用破坏了生物质形貌结构,使所制备的生物炭的比表面积由0.01 m^(2)/g提高至20.53 m^(2)/g,C—O及其他含氧官能团含量大幅增加。吸附实验表明,微生物发酵前处理所得的棉秆基生物炭对亚甲基蓝(MB)的吸附容量为64.9 mg/g,是直接碳化制备的生物炭吸附容量的8倍;发酵前后棉秆生物质所制备的2种生物炭对MB的吸附均符合准二级动力学模型,其吸附过程受生物炭活性位点数和生物炭层状结构的控制;羟基在生物炭和MB之间的相互作用中起着关键作用,是主要的活性吸附位点。
Due to the small specific surface area and low functional group content of biochar,its adsorption capacity is limited.In order to improve the adsorption performance of biochar,cotton stalk biochar was prepared by microbial pretreatment and low temperature hot air carbonization(TAT)technology.The prepared biochar has high specific surface area and high oxygen-containing functional groups.The morphology of cotton stalk biomass before and after fermentation was characterized by scanning electron microscopy(SEM).The specific surface area and functional groups of the biochar prepared were analyzed by N_(2)adsorption and desorption experiment,fourier transform infrared(FT-IR)and Raman spectroscopy.The results showed that a large number of microorganisms were attached to the surface of cotton stalk biomass obtained from microbial fermentation pretreatment,and the decomposition of microorganisms destroyed the biomass morphology,so that the specific surface area of the prepared biochar increased from 0.01 m^(2)/g to 20.53 m^(2)/g,and the contents of C—O and other orygen-containing functional groups increased greatly.The adsorption experiment showed that the adsorption capacity of cotton straw-based biochar obtained from microbial fermentation pretreatment for methylene blue(MB)was 64.9 mg/g,which was 8 times of that of biochar prepared by direct carbonization.The adsorption of MB by two kinds of biochar prepared from cotton stalk biomass before and after fermentation conformed to the quasi-second-order kinetic model.The adsorption process was controlled by the number of active sites of biochar and the layered structure of biochar.Hydroxyl played a key role in the interaction between biochar and MB,and was the main active adsorption site.
作者
蔡成坤
魏红福
刘希阳
王亚洲
CAI Chengkun;WEI Hongfu;LIU Xiyang;WANG Yazhou(School of Life Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;School of Materials and Chemistry,Southwest University of Science and Technology,Mianyang 621010,China;College of Resources,Sichuan Agricultural University,Chengdu 611130,China)
出处
《工业水处理》
CAS
CSCD
北大核心
2023年第3期80-86,共7页
Industrial Water Treatment
基金
全国大学生创新创业项目(S202110619107)
西南科技大学大学生创新基金项目精准资助专项(JZ21-071)。
关键词
亚甲基蓝
生物炭
发酵
棉秆
含氧官能团
methylene blue
biochar
fermentation
cotton stalk
oxygen-containing functional group
