湍流水体中表面活性剂对硝基苯挥发的影响

研究了在湍流水体中表面活性剂SDS、CTMAB、Tween20、Tween40、Tween60、Tween80对硝基苯挥发的影响。其规律表明:湍流(扰动)促进了硝基苯的挥发,原因是水体表面更新速度剧增和溶液的混合度增加;湍流强度和硝基苯的挥发速率常数成较好的线性关系,各线性方程的R2均大于0.97。表面活性剂对硝基苯的挥发具有抑制作用,原因是硝基苯分子与表面活性剂胶束结合的几率增加和水体表面处的表面活性剂浓度梯度的形成,不同类型的表面活性剂对硝基苯的挥发抑制能力的顺序为Tween>CTMAB>SDS;同类型Tween系列非离子表面活性剂对硝基苯挥发的抑制作用与其亲水亲油平衡值HLB呈正相关。

Influence of surfactants in turbulent waters on volatility of nitrobenzene

The influence of surfactants SDS, CTMAB, Tween20, Tween40, Tween60 and Tween80 in turbulent waters on the volatility of nitrobenzene was studied. The results indicate that the turbulence （perturbation） improves the volatility of nitrobenzene because of the sharp increases of its renewal speed at the water surface and mixing in the solution. The nitrobenzene volatility speed is linearly related to the turbulence intensity （R^2 〉 0.97）. The surfactants inhibit the nitrobenzene volatility because of the increasing probability of combination of the nitrobenzene molecule and the surfactant micelle and the formation of a concentration gradient of surfactants at the water surface. Of the surfactants, Tween has the greatest ability to inhibit nitrobenzene volatility, followed by CTMAB, and, finally, SDS. The inhibitory effect on nitrobenzene volatility of the similar Tween series non-ionic surfactants is positively related to their hydrophilic and lipophilic balance （HLB） value.