Spark K M, Swift R S
Department of Soil Science, University of Reading, Berkshire, UK.
Sci Total Environ. 2002 Oct 21;298(1-3):147-61. doi: 10.1016/s0048-9697(02)00213-9.
The effect of the solid and dissolved organic matter fractions, mineral composition and ionic strength of the soil solution on the sorption behaviour of pesticides were studied. A number of soils, chosen so as to have different clay mineral and organic carbon content, were used to study the sorption of the pesticides atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine), 2,4-D ((2,4-dichlorophenoxy)acetic acid), isoproturon (3-(4-isopropylphenyl)-1,1-dimethylurea) and paraquat (1,1'-dimethyl-4,4'-bipyridinium) in the presence of low and high levels of dissolved organic carbon and different background electrolytes. The sorption behaviour of atrazine, isoproturon and paraquat was dominated by the solid state soil components and the presence of dissolved organic matter had little effect. The sorption of 2,4-D was slightly affected by the soluble organic matter in the soil. However, this effect may be due to competition for adsorption sites between the pesticide and the soluble organic matter rather than due to a positive interaction between the pesticide and the soluble fraction of soil organic matter. It is concluded that the major factor governing the sorption of these pesticides is the solid state organic fraction with the clay mineral content also making a significant contribution. The dissolved organic carbon fraction of the total organic carbon in the soil and the ionic strength of the soil solution appear to have little or no effect on the sorption/transport characteristics of these pesticides over the range of concentrations studied.
研究了土壤溶液中固体和溶解有机物组分、矿物组成及离子强度对农药吸附行为的影响。选用了一些具有不同粘土矿物和有机碳含量的土壤，用于研究在低水平和高水平溶解有机碳以及不同背景电解质存在下，农药阿特拉津（6-氯-N2-乙基-N4-异丙基-1,3,5-三嗪-2,4-二胺）、2,4-滴（(2,4-二氯苯氧基)乙酸）、异丙隆（3-(4-异丙基苯基)-1,1-二甲基脲）和百草枯（1,1'-二甲基-4,4'-联吡啶鎓）的吸附情况。阿特拉津、异丙隆和百草枯的吸附行为主要由土壤固态组分主导，溶解有机物的存在影响不大。2,4-滴的吸附受到土壤中可溶性有机物的轻微影响。然而这种影响可能是由于农药与可溶性有机物之间对吸附位点的竞争，而非农药与土壤有机质可溶性部分之间的正向相互作用。得出的结论是，控制这些农药吸附的主要因素是固态有机组分，粘土矿物含量也有显著贡献。在所研究的浓度范围内，土壤总有机碳中的溶解有机碳组分以及土壤溶液的离子强度似乎对这些农药的吸附/迁移特性影响很小或没有影响。
