玉米秸秆还田方式对土壤吸附草甘膦的影响及作用机理  

Effect of Corn Straw Returning Mode on the Adsorption of Glyphosate by Soil and Its Mechanisms

作　　者：谭渝 刘红林 于水莲[1] 李松岩 邓翠雯 黄应平[1,3] 田海林 刘慧刚[1,2] TAN Yu;LIU Honglin;YU Shuilian;LI Songyan;DENG Cuiwen;HUANG Yingping;TIAN Hailin;LIU Huigang(Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region,Ministry of Education,China Three Gorges University,Yichang 443002,Hubei,China;College of Basic Medical Science,China Three Gorges University,Yichang 443002,Hubei,China;College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,Hubei,China)

机构地区：[1]三峡大学三峡库区生态环境教育部工程研究中心,湖北宜昌443002 [2]三峡大学基础医学院,湖北宜昌443002 [3]三峡大学水利与环境学院,湖北宜昌443002

出　　处：《武汉大学学报（理学版）》2024年第5期629-637,共9页Journal of Wuhan University:Natural Science Edition

基　　金：国家自然科学基金(21972073,22206108)。

摘　　要：以农业废弃物玉米秸秆为原料,分别通过自然焚烧和隔氧热解的方式制备玉米秸秆草木灰(CSA)和玉米秸秆生物炭(CSB),将其按质量分数1%添加至土壤(S)中制成S-CSA和S-CSB。研究了吸附剂(S、S-CSA和S-CSB)对草甘膦的吸附性能及作用机理。结果表明:与S相比,S-CSA对草甘膦的吸附量降低,S-CSB对草甘膦的吸附量升高;相同质量玉米秸秆制备的S-CSB对草甘膦的吸附量是S-CSA的15.22倍,玉米秸秆以生物炭的方式还田更有利于土壤对草甘膦的吸附。吸附剂对草甘膦的吸附过程均符合准二级动力学模型和Langmuir单分子层化学吸附模型,且吸附过程是自发的、吸热的。S-CSB对草甘膦吸附量的增加源于比表面积的增大和含氧官能团的增多,S-CSA对草甘膦吸附量的减少归因于静电斥力的增大和磷酸盐竞争吸附。Corn straw ash(CSA)and corn straw biochar(CSB)were produced from agricultural waste corn straw through natural incineration and oxygen separation pyrolysis techniques.CSA and CSB were added to the soil(S)at a mass fraction of 1%to form S-CSA and S-CSB,respectively.A comprehensive investigation was conducted to analyze the adsorption performances and mechanisms of glyphosate by absorbents(S,S-CSA,S-CSB).The results show that the adsorption capacity of glyphosate by S-CSA decreases,while the adsorption capacity of glyphosate by S-CSB increases compared with S.Notably,the adsorption capacity of S-CSB is 15.22 times as higher as that of S-CSA by the same mass of corn straw,and the return of corn straw to the field in the form of biochar is more conducive to the adsorption of glyphosate by the soil.The adsorption processes of glyphosate by adsorbents conform to the quasi-secondorder kinetic model and Langmuir monolayer chemisorption model,and the adsorption process is spontaneous and endothermic.The increase in glyphosate adsorption by S-CSB is due to the amplified specific surface area and oxygen-containing functional groups.In contrast,the decrease in glyphosate adsorption by S-CSA is attributed to the enhancement of electrostatic repulsion and phosphate competition.

关 键 词：草甘膦 秸秆还田 草木灰 生物炭 吸附 

分 类 号：X53[环境科学与工程—环境工程]