Singh R P, Kumari K, Singh D
Department of Botany, Faculty of Life Science, Aligarh Muslim University, India.
Ecotoxicol Environ Saf. 1994 Oct;29(1):70-9. doi: 10.1016/0147-6513(94)90031-0.
The effects of exchangeable cations (H+ and Na+), autoclaving, organic matter, cationic and anionic surfactants, and temperature on the adsorption of carbofuran on two different types of soils were studied. The adsorption isotherms for all effects/treatments were in close agreement with the Freundlich equation and yielded S-shaped isotherms. The amount of carbofuran adsorbed in all cases was higher in Jhansi red loam soil than in Pilibhit sandy loam soil and was related to organic matter content, clay content, CaCO3 content, surface area, and cation-exchange capacity of the soils. The adsorption on soils from both sites follows the order H soil-->Na soil-->natural soil at 25 degrees C-->autoclaved soil-->soil from which organic matter had been removed-->cationic surfactant-->anionic surfactant-->natural soil at 50 degrees C and was in accordance with Freundlich constant K values and distribution coefficient Kd values. The adsorptive capacity of carbofuran for organic matter and clay content for both the Jhansi and the Pilibhit soils was also evaluated by calculating Kom and Kc values, and it was found that the carbofuran adsorption was better correlated with clay content than with organic matter content of soils. On the basis of adsorption isotherms, various thermodynamic parameters such as the thermodynamic equilibrium constant Ko, standard free energy (delta G zero) changes standard ethalpy (delta H zero) changes, and standard entropy (delta S zero) changes have been calculated in order to predict the nature of isotherms.
研究了可交换阳离子（H⁺和Na⁺）、高压灭菌、有机质、阳离子和阴离子表面活性剂以及温度对两种不同类型土壤中呋喃丹吸附的影响。所有效应/处理的吸附等温线均与弗伦德利希方程高度吻合，并呈现出S形等温线。在所有情况下，占西红壤土中吸附的呋喃丹量均高于皮利比特砂壤土，且与土壤的有机质含量、粘土含量、碳酸钙含量、表面积和阳离子交换容量有关。在25℃时，两个地点土壤上的吸附顺序为：H型土壤＞Na型土壤＞天然土壤＞高压灭菌土壤＞去除有机质的土壤＞阳离子表面活性剂＞阴离子表面活性剂＞50℃时的天然土壤，且与弗伦德利希常数K值和分配系数Kd值一致。通过计算Kom和Kc值，还评估了占西和皮利比特土壤中呋喃丹对有机质和粘土含量的吸附能力，结果发现，呋喃丹的吸附与土壤粘土含量的相关性优于与有机质含量的相关性。基于吸附等温线，计算了各种热力学参数，如热力学平衡常数Ko、标准自由能（ΔG⁰）变化、标准焓（ΔH⁰）变化和标准熵（ΔS⁰）变化，以预测等温线的性质。
