【作者】 张瑾；

【导师】 司友斌； 岳永德；

【作者基本信息】 安徽农业大学 ， 农药学， 2003， 硕士

【摘要】 农药在土壤中的淋溶行为是农药在土壤中发生的重要环境行为之一，是地下水中农药污染的重要途径，通过对它们的研究可以了解农药在土壤中的存在状态和规律，并以此作为农药环境安全性评价的一个重要依据。 胺苯磺隆是一种新型、高效的油菜田磺酰脲类除草剂，其环境行为的研究相对较少。本论文系统介绍了胺苯磺隆在土壤中的吸附、淋溶及影响淋溶的因素以及胺苯磺隆在土壤溶液中的降解及降解产物的结构鉴定，为该除草剂使用后的环境安全性评价提供了依据。 通过研究胺苯磺隆在土壤中的吸附，用Freundlich方程描述了胺苯磺隆在3种不同类型土壤上的吸附情况，并比较了理化性质对胺苯磺隆吸附量的影响，结果表明：(1)土壤的类型不同，胺苯磺隆的吸附量不同，红壤中最大，黄褐土次之，砂姜黑土最小；(2)胺苯磺隆在土壤中的吸附能很好地与Freundlich方程相吻合，胺苯磺隆在土壤中的吸附常数K_f与土壤的有机质、粘粒含量呈正相关，与土壤pH值负相关；(3)胺苯磺隆在不同pH条件下的红壤和砂姜黑土中的吸附研究表明，随着pH值的增大，胺苯磺隆的吸附量减小，尤以在红壤中的效应最明显；(4)胺苯磺隆在土壤中的吸附以物理作用为主；(5)胺苯磺隆在红壤和黄褐土中具有中等移动性，在砂姜黑土中具有较高移动性。 通过室内模拟土柱试验，研究了人工模拟降水对胺苯磺隆在土壤中淋溶迁移的影响，结果表明：(1)胺苯磺隆淋出量与降水量的大小和降水的强度正相关；(2)降水量相同，土壤的类型不同，胺苯磺隆的淋出量也不同，淋出量的大小顺序：砂姜黑土>黄褐土>红壤；(3)胺苯磺隆的淋出量与土壤性质以及降水量之间的多元线性拟合方程显示，胺苯磺隆的淋出量与降水量的大小及降水的强度正相关，与土壤pH值正相关，与有机质含量负相关，与CEC的大小负相关，与粘粒含量的大小负相关，其中土壤pH与有机质含量的大小影响较大，而粘粒含量与降水量的大小影响次之；(4)土壤类型不同，胺苯磺隆在土壤中的分布情况随降水量的不同而不同：在黄褐土和砂姜黑土中，随降水的增多和增强，胺苯磺隆的分布深度的下移速度较快；而在吸附能力强的红壤中，胺苯磺隆在土壤中分布深度随降水的增多和增强，下移的速度较慢，即表现出了滞后现象。 以三种不同的表面活性剂(CTAB、SLBS、T-60)为对象，研究了其对胺苯磺隆在土壤中的淋溶迁移行为的影响，结果表明表面活性剂的影响效应与表面活性剂的类型和浓度有关：(1)阳离子表面活性剂CTAB阻止了胺苯磺隆在土壤中的淋溶，阴离子表面活性剂SLBS和非离子表面活性剂T-60则促进了胺苯磺隆在土壤中的淋溶，而SLBS的影响效应较T-60明显，尤其是在红壤中；(2)不同浓度的阴离子表面活性剂SLBS对胺苯磺隆在红壤中淋溶影响的结果表明，胺苯磺隆的淋出量与SLBS的浓度呈显著的正相关；（）阳离子表面活性剂CTAB改性的粘土矿物大大增强了对胺苯磺隆的吸附能力，将改性后的粘土矿物添加到砂姜黑土中，胺苯磺隆吸附量和持留量大大增加，其中Na－蒙脱石使其增加的量最多，沸石次之，膨润土最小。 通过对胺苯磺隆在腐殖质上的吸附和腐殖质对胺苯磺隆在红壤中淋溶迁移的影响的研究，并借助双光束紫外扫描和 FT二R技术，阐明了胺苯磺隆与腐殖质 （腐殖酸、泥炭、腐殖酸钠）相互作用的机理，结果表明（l）腐殖酸对胺苯磺隆的吸附较腐殖酸钠强，其吸附常数 Kf是腐殖酸钠的 100多倍：（）腐殖质对胺苯磺隆在土壤中淋溶迁移的影响与腐殖质在土壤中存在的形态和浓度有关，腐殖酸钠溶液对胺苯磺隆在红壤中的淋溶具有促进作用，在红壤中添加腐殖酸和泥炭则增大了胺苯磺隆在红壤中的持留量，腐殖质对胺苯磺隆的影响的效应均与所使用的浓度呈正相关；（3）腐殖质与胺苯磺隆之间通过氢键等作用形成了络合物，而后发生共吸附和共迁移现象。 胺苯磺隆在不同初始含水量的土壤中的淋溶研究结果表明（1）土壤初始含水量的大小直接影响胺苯磺隆淋出量的大小，即除草剂胺苯磺隆的淋出量与土壤初始含水量呈显著的正相关；（2）土壤类型不同，含水量相同时，胺苯磺隆的淋出量大小顺序为：红壤＜黄褐土＜砂姜黑土；（）土壤类型不同，胺苯磺隆在不同初始含水量的土壤中的淋溶迁移情况也不同，在黄褐土和砂姜黑土中，胺苯磺隆的分布随初始含水量的增大，胺苯磺隆的分布深度下移速度较快，而在红壤中，胺苯磺隆的分布深度下移表现出了滞后现象。 胺苯磺隆在pH缓冲液以及在土壤溶液中的水解研究结果表明门）胺苯磺隆的降解符合一级动力学方程；（2）胺苯磺隆在pH缓冲液和土壤中的降解速率与pH值的大小呈负相关，pH越小，降解越快，反之，则越慢；门）胺苯磺隆在土壤溶液中的降解半衰期与邻近pH缓冲液中的降解半衰期相近，但稍长于pH缓冲液中的降解半衰期；（4）通过对胺苯磺隆水解产物的分离和鉴定，得出10个降解产物的分子结构，并由此推出其水解历程。胺苯磺隆水解可按三条途径发生：一是胺苯磺隆的腺桥发生断裂，生成三嗓环和苯磺酚胺，三喷环和苯磺酚胺再进一步脱烷基、环化成衍生物；二是胺苯磺隆分子上竣甲基水?更多还原

【Abstract】 Leaching in soil is one of important environmental behaviors of pesticides, which is most important source of pollutants in underground water. Assessing the leaching of new pesticides has become an integrated part of studies concerning the environmental safety of pesticides.Ethametsulfuron-methyl is the sulfonylurea herbicide, which is relatively new class of compounds and effective for the control of both simple-leaf and double-leaf weeds and certain grasses in rape field. Although the investigation of leaching of ethametsulfuron-methyl in soils is required by registration authorities, knowledge of the relevant processes is limited.In this paper, adsorption, leaching and the effect of the simulated rainfall, SAA (surface active agent), humus (humic acid and its sodioum salt, peat) on the leaching of the herbicide ethametsulfuron-methyl in three kinds of soils (red soil, yellow cinnamon soil, and black soil) were studied with soil column. Hydrolysis of ethametsulfuron-methyl and its products were also provided in detail. The main results were summarized as follows:Adsorption of ethametsulfuron-methyl in soils was studied using batch equilibration technique , and the results showed that (1) the amount of ethametsulfuron-methyl adsorbed by soils varied with different soils, and followed the order: red soil > yellow Cinnamon soil > black soil; (2) adsorption of ethametsulfuron-methyl in soils fitted well the Freundlich equation, and the adsorption constant Kf, which stands for the absorbability, decreased with increasing of pH and increased with increasing of contents of OM (organic matter) and clay of soils; (3) the amount of adsorption of ethametsulfuron-methyl was negatively correlated with pH values of soils, especially in red soil; (4) free energy of sorption for ethametsulfuron-methyl on soils indicated that the adsorption belonged to physical reaction; (5) adsorption constant Koc for ethametsufruron-methyl in soils indicated that ethametsulfruon-methyl was of medium leachability in both red soil and yellow Cinnamon soil, and higher leachability in black soil.Rainfall had a great effect on the leaching of ethametsulfuron-methyl in soils:(1) The amount of ethametsufuron-methyl reclaimed in leachate increased with the rainfall increasing and followed the order: 1500mm > 1000mm > 500mm. (2)Underthe same rainfall, leaching of ethametsulfuron-methyl in different soils varied greatly, and the amount of ethametsulfuron leached in leachate followed the order: black soil >yellow cinnamon soil > red soil. (3) The relative equation of amount of ethametsulfuron-methyl in leachate with rainfall, physical and chemical parameters of soils indicated that the leaching of ethametsulfuron-methyl was consanguineously correlated with rainfall, soil characteristics such as organic matter content, clay content, and pH, i.e. the amount of ethametsufuron-methyl in leachate increased with rainfall and pH values increasing and decreased with increasing of contents of clay and OM. The distribution of ethametsulfuron-methyl varied greatly in different soils: the distribution depth of ethametsulfuron-methyl in black and yellow cinnamon soils increased instantly with rainfall increasing, while increased slowly with rainfall increasing in red soil.Three kinds of SAA were selected to observe the impact of SAA on the leaching of ethametsulfuron-methyl in soils, the results showed that the impact of SAA on the leaching of ethametsulfuron-methyl was well correlated with the kind of SAA and the concentration used. (1) cationic surfactant CTAB (cetyltrimethyl ammonium bromide) delayed the leaching of ethametsulfuron-methyl downward, whereas both nonionic surfactant T-60 (Tween-60) and anionic SLBS (sodium lauryl benzene sulfonate) accelerated the leaching of ethametsulfuron-methyl in soils. Moreover, the impact of SLBS was more remarkable than T-60, especially in red soil. (2) The amount of ethametsulfuron-methyl reclaimed in leachate increased remarkably with the concentration of SLBS increasing in elution in red soil. (3) A更多还原