生物炭对黄绵土中NO_(3)^(-)-N运移过程影响及模拟  

Effect of Biochar on NO_(3)^(-)−-N Transport in Loessial Soil and Its Simulation

作　　者：白一茹 刘旭 张钰涵 张睿媛 马艳[1] 王幼奇 BAI Yi-ru;LIU Xu;ZHANG Yu-han;ZHANG Rui-yuan;MA Yan;WANG You-qi(School of Geography and Planning,Ningxia University,Yinchuan 750021,China;School of Ecology and Environment,Ningxia University,Yinchuan 750021,China;Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwestern China,Yinchuan 750021,China)

机构地区：[1]宁夏大学地理科学与规划学院,银川750021 [2]宁夏大学生态环境学院,银川750021 [3]西北土地退化与生态恢复国家重点实验室培育基地,银川750021

出　　处：《环境科学》2024年第5期2905-2912,共8页Environmental Science

基　　金：宁夏自然科学基金项目(2023AAC03046);国家自然科学基金项目(41867003);宁夏回族自治区重点研发计划项目(2021BEG02011)。

摘　　要：为探究不同施加量生物炭对黄绵土NO_(3)^(-)-N运移过程及特征的影响,以生物炭与黄绵土质量比分别为0%(T0)、1%(T1)、2%(T2)、3%(T3)、4%(T4)和5%(T5)的6组混合土样为研究对象,以NO_(3)^(-)-N为示踪物质,通过室内土柱溶质运移模拟试验,研究了不同生物炭施加量对黄绵土中NO_(3)^(-)-N运移过程影响并进行模型模拟.结果表明,NO_(3)^(-)-N在黄绵土中的穿透曲线随生物炭施加量增加明显右移,峰值逐渐降低.初始穿透时间、完全穿透时间及穿透总历时均随生物炭施加量增大而增加,T1、T2、T3、T4和T5处理NO_(3)^(-)穿透总历时分别是T0的1.26、2.31、2.72、3.22和3.57倍.两区模型(TRM)的R2>0.997,RMSE<2.083,相较于对流-弥散方程(CDE),TRM模型拟合精度更高,能较好地模拟不同含量生物炭施加后的黄绵土中NO_(3)^(-)-N运移过程.对TRM模型拟合参数进行分析发现,随生物炭施加量增加,平均孔隙流速、水动力弥散系数和可动区含水比率均逐渐减小,而弥散度和质量交换系数呈现增加的趋势.研究显示,生物炭有效增强了黄绵土对NO_(3)^(-)-N的固持能力,减少了NO_(3)^(-)-N向地下水体的渗漏,对保持土壤肥力与防止地下水污染具有重要作用.The objective of this study was to explore the effects of different amounts of biochar on the migration process and characteristics of NO_(3)^(-)-N in loessial soil.In this study,six groups of mixed soil samples with biochar and loessial soil mass ratios of 0%(T0),1%(T1),2%(T2),3%(T3),4%(T4),and 5%(T5)were used as research objects.NO_(3)^(-)-N was used as the tracer.Through the indoor soil column solute transport simulation tests,the effects of different biochar application amounts on the NO_(3)^(-)-N transport process in loessial soil were simulated and studied.The results showed that the breakthrough curve of NO_(3)^(-)-N in loessial soil shifted to the right with the increasing of biochar application,and the peak value gradually decreased.The initial penetration time,complete penetration time,and total penetration time increased with the increasing of biochar application amount.The total penetration time of NO_(3)^(-) in the T1,T2,T3,T4,and T5 treatments was 1.26,2.31,2.72,3.22,and 3.57 times that of T0,respectively.The R2 was>0.997 and RMSE was<2.083 of the two-zone model(TRM).Compared with the convection-dispersion equation(CDE),the TRM model had higher fitting accuracy and could better simulate the NO_(3)^(-)-N migration process in loessial soil after the application of different contents of biochar.The analysis of the fitting parameters of the TRM model showed that the average pore velocity,hydrodynamic dispersion coefficient,and water content ratio in the movable zone gradually decreased with the increasing of biochar application,whereas the dispersion and mass exchange coefficient showed an increasing trend.The results showed that biochar application could effectively enhance the ability of loessial soil to fix NO_(3)^(-)-N,reduce the leakage of NO_(3)^(-)-N to groundwater,and play an important role in maintaining soil fertility and preventing groundwater pollution.

关 键 词：生物炭 硝态氮 穿透曲线 对流-弥散方程(CDE) 两区模型(TRM) 

分 类 号：X144[环境科学与工程—环境科学]