化学破乳-Fenton氧化处理乳化液废水

采用化学破乳-Fenton试剂处理乳化液废水,考察了相关因素对处理效果的影响特点和规律.实验结果表明,酸化作用中,静电作用对破乳有着关键性影响,降低乳化液废水pH值,有利于乳化液废水的油水分离;混凝剂投加量和废水pH值直接决定着破乳效果,油滴分散体系脱稳的适宜pH值既能使油滴间静电斥力较小,又能使大分子量的、大比表面积的多核络合离子通过电中和、吸附架桥、卷扫的作用来强化油水分散体系脱稳.Fenton氧化中,对于特定的Fe2+浓度,随着n(H2O2)/n(Fe2+)增加,COD去除程度增加,但增加的幅度越来越小,同时COD去除率达到稳定所需要的时间相应增加,适宜的摩尔比为20;废水Fenton体系H2O2开始阶段急速降低然后趋于平缓,体系Fe2+反应开始很短时间内急剧降低并趋于某一稳定值,H2O2浓度、Fe2+浓度随时间变化遵循一级反应动力学模型.

Chemical demulsification-Fenton oxidation of emulsion wastewater

The chemical demulsification-Fenton oxidation was used for the treatment of emulsion wastewater. The characteristics and laws of related factors on treatment effect were investigated. The results showed that electrostatic effect had a critical impact on demulsification, and low pH was advantageous to the oil-water separation of emulsion wastewater in acidification. The dosing amount of coagulant and the pH value of wastewater had a critical impact on demulsification. The appropriate pH value condition of unstability of oil droplets dispersed system should be as follows: smaller electrostatic repulsion between oil droplets, the existence of multi-core complexing ions having large molecular weight and specific surface. The multi-core complexing ions could strengthen the unstability of oil-water dispersions by charge neutralization, adsorption bridging and furl mechanism. In the Fenton oxidation system, the COD removal rate increased with the increase of H2O2/Fe2+ ratio for a certain Fe2+ dosage,but the increase rate tended to be reduced. Meanwhile, the required time of COD removal rate reaching stability increased correspondingly, and the suitable molar ratio of the H2O2/Fe2+ was 20. In the wastewater Fenton system, H2O2 concentration decreased drastically and then began to flatten, and Fe2+ concentration fell sharply in a very short time and tended to be a stable value. The change of H2O2, Fe2+ concentration with time conformed to the first order reaction kinetics model.