Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Sergio Livingstone Pohlhammer 1007, Casilla 233, Santiago, Chile.
J Agric Food Chem. 2013 Jul 3;61(26):6150-60. doi: 10.1021/jf400950d. Epub 2013 Jun 19.
Atrazine sorption was studied in six Andisol and Ultisol soils. Humic and fulvic acids and humin contributions were established. Sorption on soils was well described by the Freundlich model. Kf values ranged from 2.2-15.6 μg(1-1/n)mL(1/n)g⁻¹. The relevance of humic acid and humin was deduced from isotherm and kinetics experiments. KOC values varied between 221 and 679 mLg⁻¹ for these fractions. Fulvic acid presented low binding capacity. Sorption was controlled by instantaneous equilibrium followed by a time-dependent phase. The Elovich equation, intraparticle diffusion model, and a two-site nonequilibrium model allowed us to conclude that (i) there are two rate-limited phases in Andisols related to intrasorbent diffusion in organic matter and retarded intraparticle diffusion in the organo-mineral complex and that (ii) there is one rate-limited phase in Ultisols attributed to the mineral composition. The lower organic matter content of Ultisols and the slower sorption rate and mechanisms involved must be considered to assess the leaching behavior of atrazine.
莠去津在六种旱地土壤和腐殖土中的吸附作用研究。确定了腐殖酸和富里酸以及腐殖质的贡献。土壤对莠去津的吸附作用很好地用 Freundlich 模型描述。Kf 值范围为 2.2-15.6μg(1-1/n)mL(1/n)g⁻¹。从等温线和动力学实验中推导出了腐殖质和腐殖质的相关性。这些分数的 KOC 值在 221 和 679 mLg⁻¹ 之间变化。富里酸的结合能力较低。吸附受瞬时平衡控制，然后是时间相关的阶段。Elovich 方程、内扩散模型和双位非平衡模型使我们能够得出结论：（i）在与有机质中内扩散和有机-矿物复合物中延迟内扩散有关的旱地土壤中存在两个速率限制阶段；（ii）在腐殖土中存在一个速率限制阶段归因于矿物组成。必须考虑腐殖土中较低的有机质含量以及较慢的吸附速率和相关机制，以评估莠去津的淋溶行为。
