Parolo María Eugenia, Savini Mónica Claudia, Loewy Ruth Miriam
LIBIQUIMA, Departamento de Química, Facultad de Ingeniería, Universidad Nacional del Comahue, Buenos Aires 1400, 8300, Neuquen, Argentina.
LIBIQUIMA, Departamento de Química, Facultad de Ingeniería, Universidad Nacional del Comahue, Buenos Aires 1400, 8300, Neuquen, Argentina.
J Environ Manage. 2017 Jul 1;196:316-322. doi: 10.1016/j.jenvman.2017.03.018. Epub 2017 Mar 14.
Sorption of non-ionic organic compounds to soil is usually expressed as the carbon-normalized partition coefficient (K) assuming that the main factor that influences the amount sorbed is the organic carbon content (OC) of the soil. However, K can vary across a range of soils. The influence of certain soil characteristics on the chlorpyrifos K values variation for 12 representative soils of the Northpatagonian Argentinian region with different physicochemical properties was investigated for this study. The chlorpyrifos sorption coefficients normalized by the OC content were experimentally obtained using the batch equilibrium method; the K values ranged between 9000-20,000 L kg. The soil characteristics assessed were pH, clay content and spectral data indicative of soil organic matter (SOM) quality measured by FT-IR on the whole soil. The bands considered in the spectroscopic analyses were those corresponding to the aliphatic components, 2947-2858 cm (band A) and the hydrophilic components, 1647-1633 cm (band B). A significant relationship was found (R = 0.66) between chlorpyrifos sorption (K) and the variables pH and A/B height band ratio. The correlation between the values predicted by the derived model and the experimental data was significant (r = 0.89 p < 0.05). Thus, this methodology could be used to estimate chlorpyrifos sorption coefficient through the use of a simple, rapid, and environmentally-friendly measurement. K analysis in relation to soil properties represents a valuable contribution to the understanding of the attenuation phenomena of the organic contaminants off-site migration in the environment.
非离子有机化合物在土壤中的吸附作用通常用碳归一化分配系数（K）来表示，前提是假定影响吸附量的主要因素是土壤的有机碳含量（OC）。然而，K值在不同土壤间会有所变化。本研究调查了阿根廷北巴塔哥尼亚地区12种具有不同理化性质的代表性土壤的某些特性对毒死蜱K值变化的影响。通过批次平衡法实验得出了经OC含量归一化的毒死蜱吸附系数；K值范围在9000 - 20,000 L/kg之间。所评估的土壤特性包括pH值、粘土含量以及通过对整个土壤进行傅里叶变换红外光谱（FT - IR）测量得到的指示土壤有机质（SOM）质量的光谱数据。光谱分析中考虑的谱带是对应脂肪族成分的2947 - 2858 cm（谱带A）和亲水成分的1647 - 1633 cm（谱带B）。研究发现毒死蜱吸附量（K）与变量pH值和A/B谱带高度比之间存在显著关系（R = 0.66）。推导模型预测值与实验数据之间的相关性显著（r = 0.89，p < 0.05）。因此，该方法可用于通过简单、快速且环保的测量来估算毒死蜱吸附系数。与土壤性质相关的K分析对于理解环境中有机污染物场外迁移的衰减现象具有重要意义。
