土壤学报2023，Vol.60Issue(5)：1468-1479,12.DOI:10.11766/trxb202212050673
田间老化生物质炭结构表征及吸附铵态氮效应
Structural Characterization of Field-aging Biochar and Its Adsorption Effect on Ammonia Nitrogen
摘要
Abstract
[Objective]Biochar application in soil has a positive effect on reducing nitrogen loss and improving nitrogen utilization efficiency.However,information on the interaction between naturally aged biochar and nutrients in the field is limited.Exploring the influence mechanism of aged biochar on soil nitrogen retention is helpful to further understand the environmental and chemical process of biochar in soil.[Method]The method of in-situ embedding of biochar in nylon bags in the field and batch equilibrium adsorption experiment in the laboratory were carried out.The field experiment included four treatments,namely fresh biochar(A0),aged biochar for one year(A1),two years(A2)and three years(A3).The dynamic changes of surface structure characteristics and physicochemical properties of aged biochar and their effects on NH4-N adsorption were investigated using scanning electron microscopy,BET-specific surface,differential thermal and thermogravimetric analysis techniques.[Result]The results showed that the surface pore structure of biochar after naturally aging for three years in the field collapsed.With the increase of field aging time,the BET-specific surface area,total pore volume,mesoporous pore volume and average pore size of biochar increased,while the micropore surface area decreased.Compared with the A0 treatment,the BET-specific surface area,total pore volume and average pore size of biochar in the A3 treatment increased by 18.93％,42.31％and 20.71％,respectively,and the micropore surface area decreased by 26.17％.With respect to the chemical structure of aged biochar,the contents of C and N elements increased by 7.92％and 95.61％,respectively,and the aromatization degree and thermal stability of biochar decreased.With the increase of field aging time,the amount of NH4+-N adsorbed by biochar decreased in the order A0＞A1＞A2＞A3,although aged biochar maintained a strong adsorption capacity.Also,batch equilibrium adsorption experiments showed that the adsorption rate of biochar to NH4+-N complied with the pseudo-second-order adsorption kinetics and Langmuir models.[Conclusion]The present study suggests that the adsorption of NH4+-N to biochar mainly occurred through the single-molecular layer mechanism,followed by physical adsorption.Therefore,studies on the enrichment effect of biochar on carbon and nitrogen and the adsorption mechanism of NH4+-N are significant in exerting carbon sequestration and improving nitrogen utilization efficiency in the soil ecosystem for biochar.关键词
生物质炭/老化/结构表征/铵态氮/吸附机制Key words
Biochar/Aging/Structural characterization/Ammonium nitrogen/Adsorption mechanism分类
农业科技引用本文复制引用
黄家威,白嘉骏,关松,窦森,张家麟,王曦若..田间老化生物质炭结构表征及吸附铵态氮效应[J].土壤学报,2023,60(5):1468-1479,12.基金项目
国家重点研发计划项目(2022YFD1500304,2017YFD0200801)和国家自然科学基金项目(42077022)资助 Supported by the National Key Research and Development Program of China(Nos.2022YFD1500304,2017YFD0200801)and the National Natural Science Foundation of China(No.42077022) （2022YFD1500304,2017YFD0200801）
