Tongji University, Shanghai 200092, China.
J Hazard Mater. 2011 Jun 15;190(1-3):214-21. doi: 10.1016/j.jhazmat.2011.03.028. Epub 2011 Mar 15.
The long-term destabilization process of a water-in-oil emulsion was investigated with two different biodemulsifiers produced under different culture conditions by Alcaligenes sp. S-XJ-1. Biodemulsifier I was obtained by using paraffin as substrate at initial culture pH of 10 and biodemulsifier II was produced with waste frying oils at pH of 7. The former exhibited higher demulsifying ability and interfacial activity than the latter. Bottle test, microscopy and Turbiscan Lab(®) Expert were used to investigate the biological demulsification process. It was found that biodemulsifiers' ability to decrease the interfacial tension played a more important role in demulsification than their ability to decrease the surface tension. Owing to their amphiphilic nature, demulsification process began with the adsorption of the biodemulsifiers onto the water-oil interface. Then the biodemulsifiers reacted with the emulsifiers because of their interfacial activity. As a result, thin liquid film was removed from the surface of dispersed droplets and coalescence occurred. This led to the settling of the dispersed droplets and the clarification of the continuous phase. Turbiscan Lab(®) Expert can be used to evaluate the demulsification efficiency and to analyze the destabilization process of different biodemulsifiers. It is a rapid and accurate method to screen high-efficiency demulsifiers from other bioproducts.
采用不同培养条件下的 Alcaligenes sp. S-XJ-1 产生的两种生物破乳剂研究了水包油乳液的长期不稳定性过程。生物破乳剂 I 是在初始培养 pH 值为 10 时使用石蜡作为底物获得的，生物破乳剂 II 是在 pH 值为 7 时用废煎炸油生产的。前者表现出比后者更高的破乳能力和界面活性。采用瓶试、显微镜和 Turbiscan Lab(®) Expert 研究了生物破乳过程。结果表明，生物破乳剂降低界面张力的能力比降低表面张力的能力在破乳中起着更重要的作用。由于其两亲性，破乳过程首先是生物破乳剂吸附在油水界面上。然后，由于其界面活性，生物破乳剂与乳化剂发生反应。结果，从分散液滴的表面除去了薄的液膜，并且发生聚结。这导致分散液滴的沉降和连续相的澄清。Turbiscan Lab(®) Expert 可用于评估破乳效率并分析不同生物破乳剂的失稳过程。这是从其他生物产物中筛选高效破乳剂的快速准确方法。
