不同施肥方式下土壤颗粒稳定性及其对四环素吸附能力的影响

发布时间：2019-04-03 18:16

【摘要】：[目的]针对不同施肥方式的农田,分析土壤胶体的稳定性及其对四环素的吸附能力,探讨四环素在土壤中的胶体运移性变化。[方法]设置不施肥对照(CK)、单施化肥(NPK)和施用有机肥(OF)3种处理,湿筛沉降法筛分制备0.053~2 mm,0.002~0.053 mm和0.002 mm(土壤胶体)3个粒径组土壤颗粒,采用静置沉降和动态激光散射技术分析土壤颗粒的分散稳定性,探讨不同电解质条件下土壤胶体的凝聚动力学,用zeta电位测定仪测定不同电解质溶液下土壤胶体表面电位的变化。最后,通过吸附动力学和等温吸附试验分析不同粒径组土壤颗粒对四环素的吸附能力。[结果]CK处理中土壤胶体含量最高,且更容易凝聚,稳定性最差;施用有机肥显著提高了土壤中大颗粒(0.053~2 mm)含量,减少了土壤胶体的释放。土壤胶体临界凝絮浓度从大到小的处理分别为OF、NPK、CK。土壤颗粒对四环素的吸附能力在OF处理中最强;土壤胶体对四环素的吸附能力均远大于其他粒径的土壤颗粒和原土。[结论]施用有机肥更有利于土壤大颗粒的形成,未团聚土壤胶体粒级更小,zeta电位更负,在水体中稳定性更强,对四环素的吸附能力也更强。因此,施用有机肥可有效减少土壤中胶体的释放,并能提高胶体在水体中的稳定性及对污染物四环素的吸附,从而影响污染物四环素在土壤中的分布和迁移。
[Abstract]:[aim] to analyze the stability of soil colloid and its adsorption capacity for tetracycline in different fertilization fields, and to explore the change of colloid transport of tetracycline in soil. [methods] three groups of soil particles, 0.053 mm,0.002~0.053 mm and 0.002 mm (soil colloid), were prepared by wet sieving and precipitation, respectively, under the treatment of single application of chemical fertilizer (NPK) and organic fertilizer (OF) in non-fertilized control (CK), and the soil particles of 0.053 mm,0.002~0.053 mm and 0.002 mm (soil colloid) were prepared. The dispersion stability of soil particles was analyzed by static deposition and dynamic laser scattering, and the coagulation kinetics of soil colloids under different electrolyte conditions was discussed. The changes of soil colloid surface potential in different electrolyte solutions were measured by zeta potentiometer. Finally, the adsorption capacity of tetracycline was analyzed by adsorption kinetics and isothermal adsorption test. [results] the content of soil colloid in CK treatment was the highest, which was easier to coagulate and the stability was the worst, and the application of organic fertilizer significantly increased the content of large particles (0.053 ~ 2 mm) in soil and decreased the release of soil colloid. The critical flocculation concentration of soil colloid was OF,NPK,CK. from large to small. The adsorption ability of soil particles to tetracycline was the strongest in OF treatment, and the adsorption ability of soil colloid to tetracycline was much higher than that of other soil particles and original soil. [conclusion] the application of organic fertilizer is more favorable to the formation of large soil particles. The size of colloidal particles in unagglomerated soil is smaller, the zeta potential is more negative, the stability in water is stronger, and the adsorption capacity of tetracycline is stronger. Therefore, the application of organic fertilizer can effectively reduce the release of colloid in soil, and improve the stability of colloid in water and the adsorption of tetracycline, thus affecting the distribution and migration of tetracycline in soil.
【作者单位】：南京农业大学资源与环境科学学院;
【基金】：江苏省自然科学基金青年基金项目(BK20150682) 江苏省环保科研课题(2015005)
【分类号】：S153.3;X131.3

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