添加改性生物炭对黑土氮素吸附及淋溶特性的影响  

Effect of metal ion-modified biochar on nitrogen adsorption and migration features of black soil

作　　者：顾芳宁 韩守新 王瀚标 王玉军[1,2] 马秀兰 李莉[1,2] GU Fangning;HAN Shouxin;WANG Hanbiao;WANG Yujun;MA Xiulan;LI Li(College of Resources and Environment,Jilin Agricultural University,Changchun,Jilin 130118,China;Jilin Provincial Key Laboratory of Soil Resource Sustainable Utilization for Commodity Grain Bases,Changchun,Jilin 130118,China;Jilin Agricultural Mechanization Management Center,Changchun,Jilin 130062,China)

机构地区：[1]吉林农业大学资源与环境学院,吉林长春130118 [2]吉林省商品粮基地土壤资源可持续利用重点实验室,吉林长春130118 [3]吉林省农业机械化管理中心,吉林长春130062

出　　处：《西北农林科技大学学报（自然科学版）》2023年第10期97-106,117,共11页Journal of Northwest A&F University(Natural Science Edition)

基　　金：国家重点研发计划项目(2021YFD1500805)。

摘　　要：【目的】探究金属离子改性生物炭对黑土氮素吸附和迁移特性的影响。【方法】以玉米秸秆为原材料,在450℃煅烧1.5 h条件下制备生物炭(BC),分别用KCl、ZnCl_(2)、FeCl_(3)溶液对其进行金属离子负载改性(分别命名为K-BC、Zn-BC和Fe-BC),并进行表征分析和氮素吸附试验,筛选出最佳改性生物炭;然后在黑土中添加质量分数0.3%的最佳改性生物炭(TB),以黑土作为对照(CK),探究这2个吸附体系的氮素吸附和迁移特性。【结果】Fe-BC对NO_(3)^(-)-N和NH_(4)^(+)-N的吸附量分别为24632.79和5253.68 mg/kg,确定Fe-BC为最佳金属离子改性生物炭。Fe-BC的比表面积和平均孔径较BC提升了9.35和6.67倍。CK和TB在pH为3时对NO_(3)^(-)-N的吸附量最大,CK在pH为9时对NH_(4)^(+)-N的吸附量最大,TB在pH为5时对NH_(4)^(+)-N的吸附量最大。相较于准二级动力学方程,Elovich方程均能更好地描述CK、TB对NO_(3)^(-)-N和NH_(4)^(+)-N的吸附动力学特征;相较于Freundlich方程,Langmuir方程均能更好地描述CK、TB对NO_(3)^(-)-N和NH_(4)^(+)-N的吸附等温线;CK、TB对NO_(3)^(-)-N的吸附反应是自发、放热且无序的,对NH_(4)^(+)-N的吸附反应是自发、吸热且无序的。在氮素迁移试验中,TB对NO_(3)^(-)-N和NH_(4)^(+)-N的累积淋失量分别比CK减少53.19%和30.54%。【结论】黑土中添加Fe-BC可以有效增加对NO_(3)^(-)-N和NH_(4)^(+)-N的吸附量,降低黑土中NO_(3)^(-)-N和NH_(4)^(+)-N的淋失量,从而有效减少黑土中氮素的流失。【Objective】This study investigated the effect of metal ion modified biochar(BC)on nitrogen adsorption and transport in black soil.【Method】The corn stalk was taken as raw material to prepare BC by calcining at 450℃for 1.5 h.KCl,ZnCl_(2)and FeCl_(3)solutions were used to conduct the metal ion-loading modification(named K-BC,Zn-BC and Fe-BC,respectively).The characterization analysis and nitrogen adsorption test were conducted to determine optimum conditions.Then,0.3%(mass fraction)optimal BC(TB)was added to black soil to investigate nitrogen adsorption and migration characteristics using the black soil as control(CK).【Result】With the highest adsorption capacity of 24632.79 and 5253.68 mg/kg for NO_(3)^(-)-N and NH_(4)^(+)-N,Fe-BC was determined as the optimal metal ion-modified biochar.The specific surface area and average pore diameter of Fe-BC were 9.35 and 6.67 times higher than those of BC.CK and TB had the largest adsorption capacity for NO_(3)^(-)-N at pH of 3,CK had the largest adsorption capa-city for NH_(4)^(+)-N at pH of 9,and TB had the largest adsorption capacity for NH_(4)^(+)-N at pH of 5.Compared with the pseudo-second-order kinetic model,Elovich model better described the adsorption kinetic characteristics of CK and TB for NO 3--N and NH_(4)^(+)-N.Compared with Freundlich function,Langmuir function better described the adsorption isotherms of CK and TB for NO_(3)^(-)-N and NH_(4)^(+)-N.The adsorption reaction of CK and TB to NO_(3)^(-)-N was spontaneous,exothermic and disordered,and the adsorption reaction of CK and TB to NH_(4)^(+)-N was spontaneous,endothermic and disordered.In the nitrogen migration test,the total cumulative amounts of NO_(3)^(-)-N and NH_(4)^(+)-N leaching by TB were reduced by 53.19%and 30.54%,respectively.【Conclusion】The addition of Fe-BC to black soil effectively reduced the loss of nitrogen in black soil by enhancing the nitrogen adsorption capacity of black soil and reducing the leaching loss of NO_(3)^(-)-N and NH_(4)^(+)-N.

关 键 词：金属改性生物炭 黑土 氮素吸附特性 氮素淋溶特性 

分 类 号：S156.2[农业科学—土壤学]