首页|NaHCO3前处理对生物炭性质及其磷吸附能力的影响

NaHCO3前处理对生物炭性质及其磷吸附能力的影响

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  • 国家科技期刊平台
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为探究NaHCO3前处理对不同种类生物炭性质及其磷吸附能力的影响，借助元素分析、光电子能谱、孔径分析、扫描电镜等手段对比处理前后秸秆、壳核及其他 3类生物炭表面特性和孔结构的差异，基于吸附等温线和Freundlich与Dubinin-Radushkevich模型拟合，探讨生物炭性质控制磷吸附的机理。结果表明:NaHCO3前处理总体提高了各类生物炭的比表面积和孔体积，增幅分别为2。70％～110。84％和1。42％～123。80％，提高其芳香性(C=C)，H/C增幅为5。56％～29。41％，同时降低了极性官能团(C-O和C=O)含量，极性指数[(O+N)/C]降幅为13。18％～46。34％。原始生物炭的磷释放量范围为78。33～568。33 mg·kg-1，NaHCO3前处理显著增加各类生物炭对磷的吸附，使其表现出近似的磷吸附能力(Freundlich吸附系数KF范围为119～254 mg1-n·Ln·kg-1)，且以物理吸附为主(吸附自由能范围为5。85～7。29 kJ·mol-1)。生物炭表面特性对其磷吸附能力的影响大于孔结构，其中C-O官能团含量是关键因素。研究表明，NaHCO3前处理通过温和地改变生物炭性质，显著提高其磷吸附能力，是生物炭环境应用的另一种预处理方法。
Effects of NaHCO3 pretreatment on the properties and phosphorus adsorption capacity of biochar
In order to explore the effect of NaHCO3 pretreatment on the properties of different types of biochar and its phosphorus(P)adsorption capacity,the differences in the surface characteristics and pore structures of three types of biochar including straw,shell or kernel,and other types before and after NaHCO3 pretreatment were compared by using elemental analysis,photoelectron spectroscopy,pore size analysis,and scanning electron microscopy.The mechanisms of biochar properties affecting P adsorption were discussed based on the adsorption isotherms and related fitting results of Freundlich and Dubinin-Radushkevich models.The results showed that:After NaHCO3 pretreatment,the specific surface area and pore volume of all types of biochar were increased by 2.70％-110.84％and 1.42％-123.80％,respectively.The aromaticity(C=C)of biochar was increased with H/C increased by 5.56％-29.41％,whereas the contents of polar functional groups(C-O and C=O)were decreased with polar index(O+N)/C decreased by 13.18％-46.34％.The release amount of P from pristine biochar ranged from 78.33 mg·kg-1 to 568.33 mg·kg-1.NaHCO3 pretreatment significantly increased the adsorption capacity of P to all types of biochar,which showed similar affinities with adsorption coefficient of Freundlich,which ranged from 119 mg1-n·Ln·kg-1 to 254 mg1-n·Ln·kg-1.Furthermore,physical adsorption was the dominant effect based on the fact that all the adsorption-free energy ranged from 5.85 kJ·mol-1 to 7.29 kJ·mol-1.The contribution of biochar surface characteristics to P adsorption capacity outweighed that of pore structure,in which the content of C-O group was the key factor.This study indicated that NaHCO3 pretreatment could significantly increase P adsorption capacity of biochar through moderately changing its properties and is an alternative pretreatment approach for the environmental application of biochar.

adsorption of phosphorus on biocharNaHCO3 pretreatmentsurface characteristicpore structurepolar functional group

孟祥志、袁杰、王克勤、侯磊

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西南林业大学生态与环境学院,昆明 650224

生物炭吸附磷 NaHCO3前处理 表面特性 孔结构 极性官能团

云南省科技计划重点研发专项

202203AC100001-03

2024

10.11654/jaes.2023-0623

农业环境科学学报
农业部环境保护科研监测所 中国农业生态环境保护协会

农业环境科学学报

CSTPCD北大核心
影响因子：1.52
ISSN：1672-2043
年,卷(期)：2024.43(4)
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