基于光催化—膜分离技术的印染废水回用装置设计及其性能实验
发布时间：2019-01-02 14:41
【摘要】：全国约有61%的城市缺水,其中约31%为严重缺水。因此,寻找其它水源供应或回用废水已成为当务之急。近年来,有关应用光催化技术和膜分离技术处理印染废水的研究较少,且基本上使用悬浮型的光催化反应器,但纳米级的光催化剂粒径极小易于流失且回收困难,不利于推广。因此,本文提出联合负载型纳米Ti02三维泡沫镍光催化网和膜分离技术回用印染废水,并对其实验条件、工艺参数、回用水质和材料的失活与再生进行研究,结合数值模拟方法及其在实际工程应用的基础上,开发设计出印染废水深度净化回用装置,并利用Fluent 14.5软件优化其关键部件,为印染废水的回用提供有价值的科学理论依据和工业化应用参考。首先,采用复合电镀技术制备出负载型纳米Ti02三维泡沫镍光催化网,联合制备出的光催化网和膜分离技术回用印染废水,考察了辐照时间、pH值、压力等条件对实验的影响,并且对回用水质及膜污染进行分析。结果表明：在光催化降解实验中,pH=4,辐照90 min时,光催化的降解效率最高。在膜分离实验中,pH=10,超滤膜的通量衰退较缓；pH=4,反渗透膜的通量衰退较缓；考虑节省电耗和提高效率,反渗透压力选为0.5MPa。使用光催化技术辐照2小时,可以减缓超滤膜和反渗透膜通量衰退分别约为12%和8%,有效控制膜污染。联合光催化-膜分离技术回用印染废水后,刚果红的去除率达99.2%,色度(稀释倍数)小于3,COD含量约为20.12 mg/L,硬度约为28.03mg/L和电导率约为883 μs/cm,各水质指标不仅优于染整行业回用生产标准值,也远远优于中央空调循环系统补给水标准值。其次,对失活后的光催化网、超滤膜和反渗透膜进行再生工艺研究。实验结果表明：采用乳酸+超声波清洗后的光催化网再生效果最好,对刚果红的去除率和全新光催化网的相当。采用碱洗+氧化法对污染后的超滤膜进行清洗,积累在膜表面绝大部分的絮状污染物已经基本消失,膜通量恢复率达95%。采用碱洗+酸洗法对污染后的反渗透膜进行清洗,积累在膜表面绝大部分的晶粒污染物已经基本消失,通量恢复率可达90%以上,脱盐率恢复到97%。最后,优化光催化-膜分离技术回用印染废水的工艺流程,开发设计出印染废水深度净化回用装置,并利用数值模拟方法优化其关键部件。应用Fluent14.5软件对光催化反应器和卷式膜组件进行优化设计,为以后的实际应用打下基础。光催化反应器优化模拟结果显示：增加挡板一方面可使其内部流场的混乱度增加,在一定程度上破坏了流场的稳定性；另一方面可以增加流体的停留时间,使污染物得到进一步降解,从而降低光催化反应器的循环次数,节省电耗。挡板间距为120 mm时,在每个独立的光催化反应器空间内可以形成两个涡流。卷式膜组件优化模拟结果显示：三角形隔网比圆形隔网和正方形隔网产生了更大尺寸的旋涡。当Δ1/h=3时,隔网间距较合适,旋涡得到较充分发展,运输颗粒的作用得到较有效发挥,因此强化传质效率最为明显；当Al/h=5、8时,由于隔网的间距过长,旋涡的尾流区过度发展,从而削弱了旋涡运输颗粒的作用。
[Abstract]:About 61% of the country's cities are short of water, of which about 31% are serious water shortages. Therefore, it is imperative to find other water supply or reuse wastewater. in recent year, that research on the application of photocatalytic technology and membrane separation technology to the treatment of printing and dyeing wastewater is less, and the suspension type photo-catalytic reactor is basically used, but the nano-scale photocatalyst particle size is extremely small and is easy to drain and the recovery is difficult, and is not conducive to popularization. in this paper, a combined load-type nano-Ti02 three-dimensional foam nickel photocatalytic net and a membrane separation technology are proposed to be used for printing and dyeing wastewater, and the experimental conditions, process parameters, water quality and material loss and regeneration are studied, and the numerical simulation method and the application thereof are based on the practical engineering application. The device for deep purification of printing and dyeing wastewater is developed and its key components are optimized by Fluent 14.5 software, which provides valuable scientific theoretical basis and reference for industrial application for the return of printing and dyeing wastewater. firstly, a load-type nano Ti02 three-dimensional foam nickel photocatalytic network is prepared by adopting a composite electroplating technology, a photocatalytic net and a membrane separation technology are combined to be used for recycling the printing and dyeing wastewater, and the influence of the irradiation time, the pH value, the pressure and the like on the experiment is investigated, and the water quality and membrane pollution are analyzed. The results showed that the photocatalytic degradation efficiency was the highest in the photocatalytic degradation experiment. In the membrane separation experiment, the pH = 10, the flux of the ultrafiltration membrane is slow, the pH value is 4, the flux of the reverse osmosis membrane is slow, the power consumption and the efficiency are saved, and the reverse osmosis pressure is selected to be 0.5MPa. The degradation of the membrane and the reverse osmosis membrane flux can be reduced by about 12% and 8%, respectively, and the membrane fouling can be effectively controlled by using the photocatalytic technology for 2 hours. After the combined photocatalytic-membrane separation technology is used for the printing and dyeing wastewater, the removal rate of the Congo red is up to 99.2%, the chroma (dilution ratio) is less than 3, the COD content is about 20. 12 mg/ L, the hardness is about 28. 03mg/ L and the electric conductivity is about 883.mu. s/ cm, and the water quality indexes are not only better than the standard standard for the production of the dyeing and finishing industry, and is far superior to the standard value of the make-up water of the central air-conditioning circulating system. Secondly, the process of regeneration of the lost photocatalytic net, the ultrafiltration membrane and the reverse osmosis membrane was studied. The results of the experiment show that the photocatalytic net has the best regeneration effect after the use of the lactic acid + ultrasonic cleaning, and the removal rate of the Congo red and the equivalent of the new photocatalytic net are the best. The polluted ultrafiltration membrane was cleaned by the alkaline-washing + oxidation method, and most of the flocculent pollutants accumulated on the surface of the membrane had disappeared, and the recovery rate of the membrane flux was up to 95%. The reverse osmosis membrane after the pollution is cleaned by the alkali washing + acid washing method, the most of the grain contaminants accumulated on the surface of the membrane have disappeared, the recovery rate of the flux can reach more than 90 percent, and the desalination rate is restored to 97 percent. and finally, optimizing the process flow of the photo-catalytic-membrane separation technology to recycle the printing and dyeing wastewater, developing a device for designing and designing the depth of the printing and dyeing wastewater, and optimizing the key components by using the numerical simulation method. Fluent 14.5 software was used to optimize the photocatalytic reactor and roll-type membrane module and lay the foundation for future practical application. the optimization of the simulation results of the photo-catalytic reactor results in that the increased turbulence of the internal flow field can be increased on the one hand, and the stability of the flow field is destroyed to a certain extent; on the other hand, the residence time of the fluid can be increased, so that the pollutants can be further degraded, so that the number of cycles of the photocatalytic reactor is reduced, and the power consumption is saved. When the baffle spacing is 120 mm, two vortices can be formed in each separate photo-catalytic reactor space. The results of the optimized simulation of the roll-type membrane module show that the triangular barrier has a larger size of the vortex than the circular and square networks. When the space is 1/ h = 3, the separation distance is suitable, the vortex is fully developed, the effect of the transportation particles is more effective, and therefore, the enhancement and mass transfer efficiency is the most obvious; when Al/ h = 5, 8, the vortex wake region is over developed due to the excessively long interval of the separation net, thereby weakening the effect of the vortex transport particles.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X791
[Abstract]:About 61% of the country's cities are short of water, of which about 31% are serious water shortages. Therefore, it is imperative to find other water supply or reuse wastewater. in recent year, that research on the application of photocatalytic technology and membrane separation technology to the treatment of printing and dyeing wastewater is less, and the suspension type photo-catalytic reactor is basically used, but the nano-scale photocatalyst particle size is extremely small and is easy to drain and the recovery is difficult, and is not conducive to popularization. in this paper, a combined load-type nano-Ti02 three-dimensional foam nickel photocatalytic net and a membrane separation technology are proposed to be used for printing and dyeing wastewater, and the experimental conditions, process parameters, water quality and material loss and regeneration are studied, and the numerical simulation method and the application thereof are based on the practical engineering application. The device for deep purification of printing and dyeing wastewater is developed and its key components are optimized by Fluent 14.5 software, which provides valuable scientific theoretical basis and reference for industrial application for the return of printing and dyeing wastewater. firstly, a load-type nano Ti02 three-dimensional foam nickel photocatalytic network is prepared by adopting a composite electroplating technology, a photocatalytic net and a membrane separation technology are combined to be used for recycling the printing and dyeing wastewater, and the influence of the irradiation time, the pH value, the pressure and the like on the experiment is investigated, and the water quality and membrane pollution are analyzed. The results showed that the photocatalytic degradation efficiency was the highest in the photocatalytic degradation experiment. In the membrane separation experiment, the pH = 10, the flux of the ultrafiltration membrane is slow, the pH value is 4, the flux of the reverse osmosis membrane is slow, the power consumption and the efficiency are saved, and the reverse osmosis pressure is selected to be 0.5MPa. The degradation of the membrane and the reverse osmosis membrane flux can be reduced by about 12% and 8%, respectively, and the membrane fouling can be effectively controlled by using the photocatalytic technology for 2 hours. After the combined photocatalytic-membrane separation technology is used for the printing and dyeing wastewater, the removal rate of the Congo red is up to 99.2%, the chroma (dilution ratio) is less than 3, the COD content is about 20. 12 mg/ L, the hardness is about 28. 03mg/ L and the electric conductivity is about 883.mu. s/ cm, and the water quality indexes are not only better than the standard standard for the production of the dyeing and finishing industry, and is far superior to the standard value of the make-up water of the central air-conditioning circulating system. Secondly, the process of regeneration of the lost photocatalytic net, the ultrafiltration membrane and the reverse osmosis membrane was studied. The results of the experiment show that the photocatalytic net has the best regeneration effect after the use of the lactic acid + ultrasonic cleaning, and the removal rate of the Congo red and the equivalent of the new photocatalytic net are the best. The polluted ultrafiltration membrane was cleaned by the alkaline-washing + oxidation method, and most of the flocculent pollutants accumulated on the surface of the membrane had disappeared, and the recovery rate of the membrane flux was up to 95%. The reverse osmosis membrane after the pollution is cleaned by the alkali washing + acid washing method, the most of the grain contaminants accumulated on the surface of the membrane have disappeared, the recovery rate of the flux can reach more than 90 percent, and the desalination rate is restored to 97 percent. and finally, optimizing the process flow of the photo-catalytic-membrane separation technology to recycle the printing and dyeing wastewater, developing a device for designing and designing the depth of the printing and dyeing wastewater, and optimizing the key components by using the numerical simulation method. Fluent 14.5 software was used to optimize the photocatalytic reactor and roll-type membrane module and lay the foundation for future practical application. the optimization of the simulation results of the photo-catalytic reactor results in that the increased turbulence of the internal flow field can be increased on the one hand, and the stability of the flow field is destroyed to a certain extent; on the other hand, the residence time of the fluid can be increased, so that the pollutants can be further degraded, so that the number of cycles of the photocatalytic reactor is reduced, and the power consumption is saved. When the baffle spacing is 120 mm, two vortices can be formed in each separate photo-catalytic reactor space. The results of the optimized simulation of the roll-type membrane module show that the triangular barrier has a larger size of the vortex than the circular and square networks. When the space is 1/ h = 3, the separation distance is suitable, the vortex is fully developed, the effect of the transportation particles is more effective, and therefore, the enhancement and mass transfer efficiency is the most obvious; when Al/ h = 5, 8, the vortex wake region is over developed due to the excessively long interval of the separation net, thereby weakening the effect of the vortex transport particles.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X791
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相关期刊论文 前10条
1 李小军;;曝气生物滤池技术在污水及中水处理中的应用[J];中国高新技术企业;2015年18期
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