Flores Cecilia, Morgante Verónica, González Myriam, Navia Rodrigo, Seeger Michael
Millennium Nucleus of Microbial Ecology and Environmental Microbiology and Biotechnology EMBA, Departamento de Química, Universidad Técnica Federico Santa María, Casilla 110-V, Avenida España 1680, Valparaíso, Chile.
Chemosphere. 2009 Mar;74(11):1544-9. doi: 10.1016/j.chemosphere.2008.10.060. Epub 2008 Dec 19.
Simazine is a s-triazine herbicide that has been applied worldwide for agriculture. This herbicide is the second most commonly detected pesticide in surface and groundwater in the United States, Europe and Australia. In this study, simazine adsorption behaviour was studied in two agricultural soils of the Aconcagua valley, central Chile. The two studied soils were soil A (loam, 8.5% organic matter content) and soil B (clay-loam, 3.5% organic matter content). Three times higher simazine adsorption capacity was observed in soil A (68.03 mg kg(-1)) compared to soil B (22.03 mg kg(-1)). The simazine adsorption distribution coefficients (K(d)) were 9.32 L kg(-1) for soil A and 7.74 L kg(-1) for soil B. The simazine adsorption enthalpy in soil A was -21.0 kJ mol(-1) while in soil B the adsorption enthalpy value was -11.5 kJ mol(-1). These results indicate that simazine adsorption process in these soils is exothermic, governing H bonds the adsorption process of simazine in both the loam and clay-loam soils. These results and the potentiometric profiles of both soils, suggest that simazine adsorption in soil A is mainly governed by simazine-organic matter interactions and in soil B by simazine-clay interactions. The understanding of simazine sorption-desorption processes is essential to determine the pesticide fate and availability in soil for pest control, biodegradation, runoff and leaching.
西玛津是一种均三嗪类除草剂，已在全球农业中广泛应用。这种除草剂是美国、欧洲和澳大利亚地表水和地下水中检测到的第二常见农药。在本研究中，对智利中部阿空加瓜山谷的两种农业土壤中西玛津的吸附行为进行了研究。所研究的两种土壤分别是土壤A（壤土，有机质含量8.5%）和土壤B（粘壤土，有机质含量3.5%）。与土壤B（22.03 mg kg⁻¹）相比，在土壤A中观察到的西玛津吸附容量高3倍（68.03 mg kg⁻¹）。土壤A的西玛津吸附分配系数（Kd）为9.32 L kg⁻¹，土壤B为7.74 L kg⁻¹。土壤A中西玛津的吸附焓为-21.0 kJ mol⁻¹，而土壤B中的吸附焓值为-11.5 kJ mol⁻¹。这些结果表明，这些土壤中西玛津的吸附过程是放热的，壤土和粘壤土中西玛津的吸附过程均受氢键控制。这些结果以及两种土壤的电位分布表明，土壤A中西玛津的吸附主要受西玛津与有机质的相互作用控制，而在土壤B中则受西玛津与粘土的相互作用控制。了解西玛津的吸附-解吸过程对于确定农药在土壤中的归宿以及用于害虫防治、生物降解、径流和淋溶的有效性至关重要。
