Laboratorio de Fisicoquímica & Analítica (PachemLab), Departamento de Química, Facultad de Ciencias Básicas, Universidad Metropolitana de Ciencias de la Educación, Santiago 7760197, Chile.
Laboratorio de Química Inorgánica, Departamento de Química, Facultad de Ciencias Básicas, Universidad Metropolitana de Ciencias de la Educación, Santiago 7760197, Chile.
Int J Environ Res Public Health. 2021 Jun 9;18(12):6264. doi: 10.3390/ijerph18126264.
The sorption behavior of 2,4-dichlorophenoxyacetic acid (2,4-D) in the abundant agricultural volcanic ash-derived soils (VADS) is not well understood despite being widely used throughout the world, causing effects to the environment and human health. The environmental behavior and risk assessment of groundwater pollution by pesticides can be evaluated through kinetic models. This study evaluated the sorption kinetics and 2,4-D sorption-desorption in ten VADS through batch sorption experiments. Differences in the sorption extent for the fast and slow phases was observed through the IPD model where 2,4-D sorption kinetics was controlled by external mass transfer and intra organic matter diffusion in Andisols (C1 ≠ 0). We confirmed from the spectroscopic analysis that the carboxylate group directly drives the interaction of 2,4-D on Andisol soil. The MLR model showed that IEP, FeDCB, and pH×Silt are important soil descriptors in the 2,4-D sorption in VADS. The Freundlich model accurately represented sorption equilibrium data in all cases (Kf values between 1.1 and 24.1 µg mLg) with comparatively higher sorption capacity on Andisols, where the highest hysteresis was observed in soils that presented the highest and lowest OC content (H close to 0).
尽管 2,4-二氯苯氧乙酸(2,4-D)在世界范围内广泛使用,但它在丰富的农业火山灰土壤(VADS)中的吸附行为仍未得到很好的理解,这对环境和人类健康造成了影响。通过动力学模型可以评估农药对地下水污染的环境行为和风险评估。本研究通过批量吸附实验评估了十种 VADS 中 2,4-D 的吸附动力学和吸附-解吸。通过 IPD 模型观察到快速和慢速阶段的吸附程度存在差异,其中 2,4-D 的吸附动力学由外部传质和安山土中的有机质内扩散控制(C1 ≠ 0)。我们通过光谱分析证实,羧酸盐基团直接驱动 2,4-D 在安山土上的相互作用。MLR 模型表明,IEP、FeDCB 和 pH×Silt 是 VADS 中 2,4-D 吸附的重要土壤描述符。在所有情况下,Freundlich 模型都能准确地表示吸附平衡数据(Kf 值在 1.1 到 24.1 µg mLg 之间),并且在安山土上具有较高的吸附能力,其中在 OC 含量最高和最低的土壤中观察到最高的滞后(H 接近 0)。