铝板热连轧乳化液废水处理的实验研究

发布时间：2018-01-03 20:32

本文关键词：铝板热连轧乳化液废水处理的实验研究　出处：《重庆大学》2016年硕士论文　论文类型：学位论文

【摘要】：铝板带热连轧是铝加工的主要工艺之一,而在铝板带热连轧中使用的油-水乳化液则起着不可替代的重要作用,这种乳化液经一定的使用周期后将会变质失效,失效后的乳化液即为乳化液废水。乳化液废水由于具有较高浓度的有机物含量和油含量,直接排放会污染环境,必须经过处理以达到国家排放标准才可排放。我国铝板热连轧乳化液废水年排放量为0.57~1.54亿吨,如何合理地处理大量的乳化液废水以实现达标排放是铝加工领域内的重要课题。本文以铝板热连轧工艺产生的乳化液废水为研究对象,采用实验方法对静置—破乳絮凝—Fenton氧化工艺处理乳化液废水的工艺过程进行了研究,系统地探究了静置环节、破乳絮凝环节以及Fenton氧化环节中各工艺参数对乳化液废水处理效果的影响规律。通过实验研究分别确定了采用该工艺处理乳化液废水时各工艺环节合理的工艺条件,结果表明,对铝板热连轧工艺乳化液废水采用静置—破乳絮凝—Fenton氧化工艺处理可使乳化液废水的COD(化学需氧量)浓度达到104mg/L,符合国标二级排放对废水中COD浓度的要求,为废水经后续生化处理后实现安全排放创造了有利条件。具体研究内容和研究结果如下:(1)实验研究了静置处理过程中乳化液废水浮油层厚度与静置时间的变化关系。结果表明,静置处理能够去除乳化液废水中的游离油和悬浮油,使它们逐渐转化为浮油,在静置时间1~16min内,浮油层厚度增大,浮油层颜色变深,16~91min内,浮油层厚度不变,浮油层颜色变深,91min之后,浮油层厚度和颜色均不再变化,说明乳化液废水中能够静置上浮的悬浮油和游离油,已经完全实现向浮油的转化。(2)对经静置处理后的乳化液废水进行破乳处理,实验研究了破乳处理过程中浓硫酸投加量、反应温度、静置时间对废水中乳化油油水分离的影响。结果显示,硫酸的酸化作用破坏了废水中乳化油的状态,使乳化油一部分转化成可自发上浮的游离油和悬浮油,一部分转化为不可自发上浮的油滴胶粒,通过测定废水中层液的COD,得出在浓硫酸投加量15ml/L、反应温度50℃、静置时间180min条件下,废水COD去除率达到48.30%,是废水中乳化油油水分离的合理工艺条件。(3)对经静置—破乳处理后的乳化液废水进行絮凝处理,实验研究了絮凝处理过程中废水pH值、絮凝剂Al2(SO4)3或FeCl3的投加量对废水中油滴聚结的影响。结果表明,Al2(SO4)3和FeCl3的絮凝聚结作用都能够去除废水中由乳化油转化成的油滴胶粒,Al2(SO4)3絮凝作用比FeCl3大,在Al2(SO4)3投加量4g/L、废水pH值为7.20、静置时间180min的条件下,COD去除率达到85.70%,乳化液废水的COD浓度由8480mg/L降低到了1212mg/L,是废水中油滴胶粒聚结的合理工艺条件。(4)对经静置—破乳絮凝处理后的乳化液废水进行Fenton氧化处理,实验研究了Fenton氧化处理过程中H_2O_2投加量、FeSO_4·7H_2O投加量、废水pH值对废水有机物去除率的影响,用COD表征废水中有机物的含量,分析了各因素的单独影响及其交互影响。结果显示,H_2O_2的投加量比FeSO_4?7H_2O投加量和废水pH值对废水COD的去除率的影响更显著,而后两者影响力相当,结合废水处理的有效性和经济性考虑,得出在废水pH值为3.5、H_2O_2的投加量45ml/L,FeSO_4?7H_2O投加量1.75g/L,氧化反应时间120min的条件下,废水COD去除率达到98.77%,是Fenton氧化处理乳化液废水的合理工艺条件。(5)采用静置—破乳絮凝—Fenton氧化工艺处理乳化液废水,各工艺环节都在合理的工艺条件下时,可使乳化液废水的COD浓度达到104mg/L,符合国标二级排放对废水中COD浓度的要求,为废水经后续生化处理后实现安全排放创造了有利条件。
[Abstract]:Aluminum strip hot rolling is one of the main process of aluminum processing, and used in hot rolling oil on aluminum water emulsion plays an irreplaceable important role. This kind of emulsion by periodicity will metamorphic failure after failure, the emulsion for emulsion wastewater emulsion wastewater. The content of organic matter and oil content in higher concentration, direct emissions will pollute the environment, must be processed to meet the national emission standards before discharge. The annual emissions of China's aluminum hot rolling emulsion wastewater is 0.57~1.54 million tons, how to reasonably large number of emulsion wastewater treatment to achieve discharge standards is an important topic in aluminum processing field in the emulsion wastewater produced by aluminum hot rolling process as the research object, using the experiment method to process the static - demulsification flocculation Fenton oxidation process of emulsion wastewater treatment Study systematically explores the static link, influence of various process parameters of demulsification flocculation and Fenton oxidation process on the part of emulsion wastewater treatment. The process conditions of emulsion wastewater when each process reasonable were determined through the experimental results show that the aluminum hot rolling process of emulsified liquid waste water with static - demulsification flocculation Fenton oxidation process can make the emulsion wastewater COD (chemical oxygen demand) concentration reached 104mg/L, with two GB emission requirements on COD concentration in the wastewater, and create favorable conditions for the wastewater after the follow-up biochemical treatment to achieve safe discharge. The specific research contents and results are as follows: (1) experimental study on the relationship between the static process of emulsion wastewater from the floating oil thickness and change the static time. The results show that the static treatment can remove emulsion in Wastewater Free of oil and suspended oil, make them gradually into the oil slick, in static 1~16min, oil layer thickness increases, the oil layer become darker in color, 16~91min, oil layer thickness and oil layer become darker in color, 91min, thickness of oil layer and color have no change, said suspension emulsion waste oil the water can be static and free floating oil, has been fully realized to the oil slick transformation. (2) of the demulsification of emulsion wastewater from static treatment, experimental study on the demulsification process of sulfuric acid dosage, reaction temperature and time on the effect of oil-water separation of emulsified oil in wastewater by static. The results showed that the acidification effect of sulfuric acid destroys the emulsified oil wastewater in the state, the emulsified oil is partially transformed into free oil and suspended oil can spontaneously go up, a part can not be transformed into spontaneous floating oil droplet particles, through the determination of waste water layer liquid COD, too The dosage of concentrated sulfuric acid 15ml/L, reaction temperature is 50 DEG C, the static time 180min conditions, the removal rate of COD reached 48.30%, is the reasonable process conditions of oil-water separation of emulsified oil in wastewater. (3) on the flocculation treatment by static - emulsion wastewater demulsification treatment, experimental study on the wastewater pH in the process of flocculation, flocculant Al2 (SO4) 3 or FeCl3 dosage of wastewater of oil droplet coalescence. The results showed that Al2 (SO4) 3 and FeCl3 flocculation and coalescence effect to removal of wastewater by emulsified oil into the oil droplet particles, Al2 (SO4) 3 flocculation more than FeCl3, in Al2 (SO4) 3 dosage is 4g/L, wastewater pH value is 7.20, the static time under the condition of 180min, the removal rate of COD reached 85.70%, the concentration of COD emulsion wastewater is decreased from 8480mg/L to 1212mg/L, is the reasonable process conditions of wastewater of oil droplet coalescence of particles of (4). The static - demulsification flocculation treatment Fenton oxidation treatment of emulsion wastewater, experimental study of Fenton oxidation process in H_2O_2 dosage, FeSO_4 dosage of 7H_2O wastewater, effects of pH on removal of organic wastewater, with the content of organic matter in wastewater characterization of COD, analyzes the influence of various factors alone and interactive effects. The results showed H_2O_2, the dosage ratio of FeSO_4? 7H_2O dosage and pH value of wastewater on the removal rate of wastewater COD effect is more significant, the latter two influence, combined with effective and economical wastewater treatment, the wastewater in pH was 3.5, the dosage of H_2O_2 45ml/L, FeSO_4 7H_2O dosage? The amount of 1.75g/L, reaction time 120min, the removal rate of COD reached 98.77%, is the reasonable process conditions of emulsion wastewater treatment. The oxidation of Fenton (5) with static - demulsification flocculation Fenton oxidation process of emulsion wastewater treatment, each process Under the reasonable process conditions, the COD concentration of emulsion wastewater can reach 104mg/L, which is in line with the requirements of the national standard two level discharge to the COD concentration of wastewater. It creates favorable conditions for the safe discharge of wastewater after subsequent biochemical treatment.

【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X76

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