| 周垂帆,林静雯,李莹,刘爱琴.磷与草甘膦在酸性土壤中吸附解吸交互作用机制[J].农业环境科学学报,2016,35(12):2367-2376. |
| 磷与草甘膦在酸性土壤中吸附解吸交互作用机制 |
| Competitive adsorption and desorption of glyphosate and phosphate on acid soil |
| 投稿时间：2016-06-29 |
| DOI：10.11654/jaes.2016-0862 |
| 中文关键词: 草甘膦 磷 吸附竞争 解吸 |
| 英文关键词: glyphosate phosphate competitive adsorption disorption |
| 基金项目:国家自然科学基金项目（31400465）；福建省自然科学基金青年基金项目（2015J05050）；中国博士后科学基金项目（2015M570550） |
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| 中文摘要: |
| 过量的磷肥和草甘膦是我国南方土壤中两种共存污染物，通常伴随着水土流失引起面源污染，为揭示土壤中草甘膦和磷的保持、释放规律及其相互影响机制，通过等温吸附-解吸试验，研究了红壤和黄壤经草甘膦处理后对磷的吸附解吸规律以及磷对草甘膦在红壤和黄壤中吸附解吸行为的影响。结果表明，草甘膦作用下磷在供试土壤上的吸附行为可用Langmuir方程描述，红壤和黄壤对磷的吸附反应均是自发进行的吸热反应，两种土壤对磷的吸附量均随草甘膦浓度增加而下降。与对照相比，红壤经草甘膦处理后，对高浓度磷的解吸具有明显抑制作用，而黄壤磷解吸量在草甘膦作用下变化不明显，但解吸率随草甘膦浓度增加有所上升。此外，Freundlich方程对磷作用下草甘膦在供试土壤上的吸附行为拟合效果较好。未添加磷时，草甘膦在黄壤上的吸附量大于其在红壤上的吸附量，然而随着磷浓度增加，黄壤对草甘膦的吸附量减少。草甘膦在两种土壤上的解吸率均呈下降趋势，随着外源磷浓度增加，草甘膦在红壤上的解吸量和解吸率均显著降低，而不同磷处理下黄壤草甘膦解吸量变化一般在1.83~8.42 mmol·kg-1之间，外源磷对草甘膦在黄壤上的解吸影响较小。以上研究表明，土壤中草甘膦和磷存在着吸附行为的竞争，草甘膦能够降低土壤对磷的吸附，同时磷也能够抑制土壤对草甘膦的吸附。 |
| 英文摘要: |
| The interaction of adsorption and desorption of glyphosate and phosphoate was investigated by conducting an isothermal adsorption-desorption experiment using red soil and yellow soil from Fujian Province. The results showed that the Langmuir equation best explained the phosphate adsorption behavior in red soil and yellow soil affected by glyphosate. Phosphate adsorption was a spontaneous endothermic reaction in both red soil and yellow soil, and the spontaneous tendency of glyphosate absorption was lower as the concentration of glyphosate increased. The phosphate adsorption quantity declined with increasing glyphosate levels in red and yellow soil. Compared to control, glyphosate inhibited desorption of high concentration phosphate. Moreover, the Freundlich and Langmuir adsorption isotherm equations explained the glyphosate adsorption process in both soils, and the Freundlich fitted better. In the absence of phosphate treatment, the adsorption of glyphosate in yellow soil was higher than red soil, but the adsorption quantity decreased with increasing concentration of phosphate in yellow soil. The glyphosate desorption quantity did not have noticeable regularity in red soil and yellow soil, and the desorption ratio declined, which was mainly influenced by adsorption quantity. However, with increasing phosphate concentration, desorption quantity of glyphosate decreased in red soil, and the desorption ratio also accordingly declined. Under different phosphate treatments, the variation of glyphosate desorption quantity ranged from 1.83~1.83 mmol·kg-1 in yellow soil, so phosphate did not strongly affect the desorption of glyphosate in yellow soil. Therefore, glyphosate and inorganic phosphate appear to compete for the same sorption sites, hence the applications of glyphosate and phosphorus may influence the bioavailability and transport potential of each other in the soil. |
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