冻融对东北黑土硒酸盐吸附解吸的影响  

Effects of initial water content and freeze-thawing cycles on adsorption and desorption of selenate in black soil of Northeast China

作　　者：行文静 牛浩 李娇[1,2] 吴福勇[1,2] XING Wen-jing;NIU Hao;LI Jiao;WU Fu-yong(College of Natural Resources and Environment,Northwest A&F University,Yangling 712100,Shaanxi,China;Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China,Ministry of Agriculture,Yangling 712100,Shaanxi,China)

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]农业部西北植物营养与农业环境重点实验室,陕西杨凌712100

出　　处：《土壤通报》2021年第2期338-345,共8页Chinese Journal of Soil Science

基　　金：国家重点研发计划战略性国际科技创新合作重点专项“黑土侵蚀防治机理与调控技术”(2016YFE0202900)资助。

摘　　要：为探究冻融过程对东北黑土硒酸盐(Se(Ⅵ))吸附、解吸的影响机理,通过室内不同初始含水率及冻融次数模拟冻融循环,随后利用冻融后土壤进行Se(Ⅵ)的吸附和解吸试验,分别采用Langumuir和Freundlich方程对Se(Ⅵ)吸附过程进行拟合。结果表明:冻融显著(P <0.05)改变了东北黑土pH值、有机质、球囊霉素相关土壤蛋白及各粒级团聚体含量,冻融后土壤Se(Ⅵ)吸附量显著高于未冻融土壤。通过拟合发现东北黑土对Se(Ⅵ)的吸附更符合Langmuir模型(R2> 0.967),高初始含水率及冻融循环次数均增加了冻融后黑土对Se(Ⅵ)的最大吸附量及缓冲容量,同时提高了Se(Ⅵ)的解吸率。70%含水率及多次冻融循环提高了黑土对Se(Ⅵ)的吸附潜能,促进Se(Ⅵ)的解吸,使得冻融后土壤硒的生物有效性增加,有利于作物根系对硒的吸收。In order to investigate the effects of freeze-thaw process on the adsorption and desorption of selenate(Se(Ⅵ)), black soil was subjected to freezing and thawing treatments with different moisture and cycles through indoor simulation. The soil after freezing and thawing was used for Se(Ⅵ) adsorption and desorption experiments. In addition Langumuir and Freundlich were respectively used to fit the process of Se(Ⅵ) adsorption. The results showed that both freezing and thawing significantly(P < 0.05) changed the pH value, organic matter, glomalin-related soil protein,and aggregate content of each particle size of the black soil in Northeast China.The amount of Se(Ⅵ) adsorption in the soil after freezing and thawing was significantly higher than that in the unfreezing and thawing soil. It is found that the adsorption of Se(Ⅵ) in black soil is more in line with the Langmuir model(R2 > 0.967). Both the high initial moisture content and the number of freeze-thaw cycles increased the maximum adsorption capacity, buffer capacity of black soil to Se(Ⅵ) and the desorption rate of Se(Ⅵ). The 70% of moisture content and multiple freeze-thaw cycles increased the adsorption potential of black soil for Se(Ⅵ), promoted the desorption of Se(Ⅵ), and increased the bioavailability of selenium in the soil, which would facilitate the absorption of selenium by crop roots.

关 键 词：初始含水量 冻融次数 黑土 硒酸盐 吸附解吸 

分 类 号：S147.2[农业科学—肥料学]