含氮表面活性剂促进矿物润滑油生物降解的作用与机制

Effect and Mechanism of Nitrogenous Surfactants on Biodegradation of Mineral Lubricating Oil

以液体石蜡模拟矿物润滑油基础油,通过生物降解实验考察了脂肪酸乙醇胺、脂肪酸酰胺、羟乙基咪唑啉、酰基氧化胺4种含氮表面活性剂对其生物降解性的影响,分别采用紫外-可见光分光光度计和表面张力仪测定了液体石蜡生物降解体系在600nm波长处的光密度和油-水界面张力。结果表明,4种含氮表面活性剂均可显著提高液体石蜡的生物降解性,其中酰基氧化胺的效果最好;当其以质量分数1.0%加入液体石蜡时,可使后者的生物降解率由33.76%提高至72.13%。生物降解过程中,含氮表面活性剂显著降低体系的油-水界面张力并加速微生物生长,从而起到促进润滑油生物降解之作用。

Impacts of four nitrogenous surfactants,viz.fatty acidic ethanolamine,fatty acidic amide and hydroxyl imidazoline,and acyl amine oxide,as additives on biodegradation of liquid paraffin were tested by a biodegradation tester.Thereafter,the optical density at 600 nm wavelength and oil-water interfacial tension of the biodegradation system were determined by ultraviolet-visible spectrophotometer and interfacial tension instrument,respectively.The results indicated that the biodegradability of liquid paraffin was markedly enhanced by nitrogenous surfactants,among which acyl amine oxide was the best candidate.The biodegradability of liquid paraffin increased from33.76% to 72.13% after formulated with acyl amine oxide at mass fraction of 1.0%.The stimulation of nitrogenous surfactants to liquid paraffin biodegradation was ascribed to the dramatic decrease of oil-water interfacial tension and the obvious increase of microbial populations in the biodegradation system.