协同空化效应降解水中咖啡因的研究
发布时间：2019-01-02 18:28
【摘要】：咖啡因(CAF)是世界上使用最广泛的药物之一,作为一种生物碱,它广泛存在于天然植物中,咖啡因对人体的神经系统有一定的作用,适度短期的使用它能驱除疲劳和兴奋神经,如果长期且过量的使用它不但对人体造成成瘾性,同时,对人体也有损害作用。海洋、湖水、河流等水体中的咖啡因的高频率出现,以致咖啡因被当为水污染的指示物。本文研究了两种不同体系对CAF降解的影响,包括超声空化协同钴离子活化过硫酸钠(US/Co2+/PS)体系与超声空化协同钴离子活化过硫酸氢钾(US/Co2+/PMS)体系。通过不同组合工艺对咖啡因溶液的降解确定了最佳反应条件,考察了单因素对咖啡因降解效率的影响,并且探究了咖啡因的矿化率,还研究了US/Co2+/PMS体系下水中共存物质对咖啡因降解率的影响。本文还通过模拟计算软件FLUENT对文丘里管、文丘里管-多孔板以及多孔板水力空化器展开模拟,探讨了结构参数及空化器类型对空化效果的影响。结果表明：(1) US/Co2+/PS体系可有效降解CAF,在初始咖啡因浓度为20 mg/L,超声功率为200W,过硫酸钠剂量为10mM,钴离子浓度为0.5 mM,溶液初始pH为2.2时反应8小时,咖啡因降解率为57.4%,并且超声空化与钴离子活化过硫酸钠有良好的协同效应,可以有效地加快反应速度,增加咖啡因的降解率。(2) US/Co2+/PMS体系可快速降解CAF,在过硫酸氢钾用量为0.5mM,钴离子浓度为0.02 mM,溶液初始pH为7.0,初始咖啡因浓度为50 mg/L,超声功率为200W,反应时间为40分钟时,咖啡因几乎被完全降解,其降解率达到了99.0%,并且超声空化与钴离子活化过硫酸氢钾的协同效果明显。增加钴离子与过硫酸氢钾的浓度,咖啡因的降解速率明显加快,在过硫酸氢钾用量为1.0 mM,钴离子浓度为0.1mM,溶液初始pH为7.0时反应4分钟,相同浓度的咖啡因被完全降解。水中共存无机物(Cl-、HCO3-、NO3-)与有机物(NaA)对咖啡因对咖啡因的降解有不同程度的抑制作用。(3)对于文丘里管空化器,当开孔率为0.025,出口锥角为6。时,空化效果最好；单孔文丘里管的空化效果好于文丘里管-多孔板的空化效果；相同开孔率下,孔数越少,多孔板空化器的空化效果越好；文丘里管-多孔板的空化效果比多孔板空化器的空化效果好。
[Abstract]:Caffeine (CAF) is one of the most widely used drugs in the world. As an alkaloid, caffeine widely exists in natural plants. Caffeine plays a certain role in the nervous system of human body. Moderate short-term use of it can remove fatigue and excitatory nerves, if it is used for a long time and excessive use, it will not only cause addiction to human body, but also damage human body. Caffeine occurs so frequently in oceans, lakes, rivers and other waters that caffeine is used as an indicator of water pollution. In this paper, the effects of two different systems on the degradation of CAF were studied, including ultrasonic cavitation and cobalt ion activated sodium persulfate (US/Co2 / PS) system and ultrasonic cavitation combined cobalt ion activated potassium persulfate (US/Co2 / PMS) system. The optimum reaction conditions for the degradation of caffeine solution were determined by different combination processes. The effect of single factor on the degradation efficiency of caffeine was investigated, and the mineralization rate of caffeine was explored. The effect of coexisting substances in water on the degradation rate of caffeine in US/Co2 / PMS system was also studied. The simulation software FLUENT is used to simulate Venturi tube, Venturi tube-perforated plate and perforated plate hydraulic cavitation device, and the influence of structure parameters and cavitation type on cavitation effect is discussed. The results show that: (1) US/Co2 / PS system can effectively degrade CAF, at the initial caffeine concentration of 20 mg/L, ultrasound power of 200W, sodium persulfate dose of 10mm, cobalt ion concentration of 0.5 mM,. When the initial pH of the solution was 2. 2, the reaction time was 8 hours, the degradation rate of caffeine was 57.4, and the ultrasonic cavitation had a good synergistic effect with cobalt ion activated sodium persulfate, which could effectively accelerate the reaction rate. (2) US/Co2 / PMS system can rapidly degrade CAF, with 0.5mm potassium persulfate, 0.02 mM, solution with initial pH of 7.0 and 50 mg/L, with initial caffeine concentration of 50 mg/L,. When ultrasonic power was 200W and reaction time was 40 minutes, caffeine was almost completely degraded, and the degradation rate reached 99.0. The synergistic effect of ultrasonic cavitation and cobalt ion activation on potassium persulfate was obvious. When the concentration of cobalt ion and potassium persulfate was increased, the degradation rate of caffeine was accelerated obviously. When the amount of potassium persulfate was 1.0 mM, the concentration of cobalt ion was 0.1 mm, and the initial pH of solution was 7.0, the reaction time was 4 minutes. Caffeine of the same concentration is completely degraded. Coexisting inorganic compounds (Cl-,HCO3-,NO3-) and organic compounds (NaA) inhibited the degradation of caffeine in different degrees. (3) for Venturi tube cavitators, when the opening ratio was 0.025, the outlet cone angle was 6. The cavitation effect of single-hole Venturi tube is better than that of Venturi tube-porous plate, and the cavitation effect of porous plate cavitation device is better when the number of holes is less under the same opening rate. The cavitation effect of Venturi tube-porous plate is better than that of perforated plate cavitation device.
【学位授予单位】：齐鲁工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52
本文编号：2398829
[Abstract]:Caffeine (CAF) is one of the most widely used drugs in the world. As an alkaloid, caffeine widely exists in natural plants. Caffeine plays a certain role in the nervous system of human body. Moderate short-term use of it can remove fatigue and excitatory nerves, if it is used for a long time and excessive use, it will not only cause addiction to human body, but also damage human body. Caffeine occurs so frequently in oceans, lakes, rivers and other waters that caffeine is used as an indicator of water pollution. In this paper, the effects of two different systems on the degradation of CAF were studied, including ultrasonic cavitation and cobalt ion activated sodium persulfate (US/Co2 / PS) system and ultrasonic cavitation combined cobalt ion activated potassium persulfate (US/Co2 / PMS) system. The optimum reaction conditions for the degradation of caffeine solution were determined by different combination processes. The effect of single factor on the degradation efficiency of caffeine was investigated, and the mineralization rate of caffeine was explored. The effect of coexisting substances in water on the degradation rate of caffeine in US/Co2 / PMS system was also studied. The simulation software FLUENT is used to simulate Venturi tube, Venturi tube-perforated plate and perforated plate hydraulic cavitation device, and the influence of structure parameters and cavitation type on cavitation effect is discussed. The results show that: (1) US/Co2 / PS system can effectively degrade CAF, at the initial caffeine concentration of 20 mg/L, ultrasound power of 200W, sodium persulfate dose of 10mm, cobalt ion concentration of 0.5 mM,. When the initial pH of the solution was 2. 2, the reaction time was 8 hours, the degradation rate of caffeine was 57.4, and the ultrasonic cavitation had a good synergistic effect with cobalt ion activated sodium persulfate, which could effectively accelerate the reaction rate. (2) US/Co2 / PMS system can rapidly degrade CAF, with 0.5mm potassium persulfate, 0.02 mM, solution with initial pH of 7.0 and 50 mg/L, with initial caffeine concentration of 50 mg/L,. When ultrasonic power was 200W and reaction time was 40 minutes, caffeine was almost completely degraded, and the degradation rate reached 99.0. The synergistic effect of ultrasonic cavitation and cobalt ion activation on potassium persulfate was obvious. When the concentration of cobalt ion and potassium persulfate was increased, the degradation rate of caffeine was accelerated obviously. When the amount of potassium persulfate was 1.0 mM, the concentration of cobalt ion was 0.1 mm, and the initial pH of solution was 7.0, the reaction time was 4 minutes. Caffeine of the same concentration is completely degraded. Coexisting inorganic compounds (Cl-,HCO3-,NO3-) and organic compounds (NaA) inhibited the degradation of caffeine in different degrees. (3) for Venturi tube cavitators, when the opening ratio was 0.025, the outlet cone angle was 6. The cavitation effect of single-hole Venturi tube is better than that of Venturi tube-porous plate, and the cavitation effect of porous plate cavitation device is better when the number of holes is less under the same opening rate. The cavitation effect of Venturi tube-porous plate is better than that of perforated plate cavitation device.
【学位授予单位】：齐鲁工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52
【参考文献】
相关期刊论文 前1条
1 施跃锦;;Fenton反应的应用及其影响因素的研究[J];贵州化工;2009年02期
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