Tween20在海洋沉积物上的吸附行为

Sorption Behavior of Tween20 on Marine Sediments

研究非离子表面活性剂Tween20在海洋沉积物上的吸附行为。发现沉积物中有机质和粘土矿物的含量对其吸附起主要作用。在实验浓度范围内,Tween20在HCl和H2O处理沉积物上的吸附行为可用线性等温式描述,而在H2O2处理样上的吸附行为可用Freundlich等温式来描述。海水的离子强度和温度都影响其吸附行为:离子强度增加,温度降低,会使沉积物的吸附能力增加。根据热力学函数关系计算出吸附焓ΔHθ为-32.98 kJ/mol,吉布斯自由能ΔGθ为-16.01^-16.99kJ/mol,吸附熵ΔSθ<0。Tween20在海洋沉积物上的吸附是一自发放热的过程。

In this study, the sorption behavior of Tween20 on marine sediments was investigated. It was found that sediment organic carbon and clay content played a critical role on the sorption of Tween20. Sorption behavior of Tween20 on HC1 and H2O-treated sediments was fit with linear isotherms very well over the concentration range at 298 K, while the sorption on H2O2-treated sediments was fit with the Freundlich isotherm model. The sorption was favorably influenced by decreasing temperature and increasing ionic strength of seawater. On the basis of thermodynamic function calculation it was obtained that the change of Gibbs free energy △G^θ=-16.01— -16.99 kJ/mol, the enthalpy change △H^θ = - 32.98 kJ/mol and the entropy change △S^θ〈 0 for the sorption. The negative AGo value obtained indicated that the sorption was a spontaneous and exothermic process which accompanied a decrease in the degree of freedom.