含乳化油废水新型破乳处理方法实验研究

发布时间：2018-12-18 13:07

【摘要】：乳化油废水排放量大、性质稳定,难以去除,危害程度高。这是由于乳化剂分子在油-水界面上定向吸附并形成坚固的界面膜,同时增大了扩散双电层的有效厚度,并且使双电层的电位分布宽度和陡度增大,从而使油高度均匀而稳定的分散在水中,不易去除。因此要实现乳化油的分离去除,技术关键是破乳,即消除或减弱乳化剂的作用,破坏油-水界面上的吸附膜,减少分散粒子所带的同种电荷量,以实现乳化油和水的有效分离。实验以40mg/L乳化油水样为处理对象,分别采用硫酸铝、氯化铁、聚合氯化铝和聚丙烯酰胺四种常用絮凝剂进行破乳实验,探讨了絮凝剂破乳的可行性和乳化油去除效果的影响因素。在合适的絮凝破乳剂投加量的条件下,四种絮凝剂均具有一定的破乳能力,乳化油的去除率均受pH影响,且无机絮凝剂破乳效果受pH影响显著,即pH是絮凝剂破乳的重要影响因素。根据前期实验提出酸化曝气破乳处理方法,首先在pH为3-4条件下对乳化油水样进行曝气处理,然后投加适量的絮凝剂进行破乳反应,再经沉淀和投加浮选剂聚合硫酸铁进行浮选,可取得较好的乳化油去除效果：硫酸铝投加量0.6 mg/L,乳化油去除率为84.2%；氯化铁投加量0.6mg/L,乳化油去除率为88.9%；聚合氯化铝投加量0.5mg/L,乳化油去除率为92.5%；聚丙烯酰胺投加量0.6mg/L,乳化油去除率为95.5%。这是由于pH为3-4时,表面活性剂可以与酸作用生成不溶于水的脂肪酸或脂肪醇,从而破坏了乳化油系统的稳定性,实现破乳。酸化曝气破乳工艺设备简单,处理效果比较稳定,尤其适用于酸性含乳化油废水,有效提高了乳化油的去除率,为含乳化油废水的破乳处理提出了新的思路。
[Abstract]:Emulsified oil wastewater discharge is large, stable, difficult to remove, high degree of harm. This is because the emulsifier molecules adsorb on the oil-water interface and form a solid interfacial film, which increases the effective thickness of the diffusion double layer and increases the potential distribution width and steepness of the double electric layer. So that the oil highly uniform and stable dispersion in water, not easy to remove. Therefore, to realize the separation and removal of emulsified oil, the key technology is to demulsify, that is, to eliminate or weaken the effect of emulsifier, to destroy the adsorption membrane on the oil-water interface, to reduce the amount of the same charge carried by dispersed particles, and to realize the effective separation of emulsified oil and water. The demulsification experiments were carried out with four common flocculants, aluminum sulfate, ferric chloride, polyaluminum chloride and polyacrylamide, respectively. The feasibility of flocculant demulsification and the influencing factors of emulsified oil removal were discussed. Under the condition of proper dosage of flocculant demulsifier, all four flocculants have certain demulsification ability, the removal rate of emulsified oil is affected by pH, and the demulsifying effect of inorganic flocculant is influenced by pH. That is, pH is an important factor affecting the demulsification of flocculant. According to the previous experiments, the acidified aeration demulsification treatment method was put forward. Firstly, the emulsified oil and water samples were aerated under the condition of pH of 3-4, and then the demulsification reaction was carried out by adding appropriate amount of flocculant. After precipitation and floatation of polyferric sulfate, a better removal effect of emulsified oil can be obtained: the removal rate of emulsified oil by adding 0.6 mg/L, aluminum sulfate is 84.2; The removal rate of emulsified oil is 88.9, the dosage of polyaluminium chloride is 0.5 mg / L, the removal rate of emulsified oil is 92.5, the dosage of polyacrylamide is 0.6 mg / L, the removal rate of emulsified oil is 95.5g / L. This is because when pH is 3-4, surfactant can react with acid to form water-insoluble fatty acids or fatty alcohols, thus destroying the stability of emulsified oil system and realizing demulsification. The acidified aeration demulsification process has the advantages of simple equipment, stable treatment effect, especially suitable for acid emulsified oil wastewater, which effectively improves the removal rate of emulsified oil, and puts forward a new idea for the demulsification treatment of emulsified oil wastewater.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X74

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