【作者】 颜廷燕；

【导师】 孙津生；

【作者基本信息】 天津大学 ， 化学工程， 2008， 硕士

【摘要】 水是生命之源,是地球上唯一不可替代的自然资源。随着我国经济的快速增长,水体污染和水环境生态日益恶化已严重制约了我国经济发展,水资源的保护及废(污)水的有效治理己成为我国面临的最严峻的挑战之一。作为污水处理技术的一种强化措施,磁处理技术与活性污泥法、厌氧流化床技术、人工生态法等的藕合,在实际应用中均取得了可喜的效果。为了探索磁场强化废水生物降解机理,并为下一步磁技术在废水处理中的应用打下基础,本文采用磁场强化——高梯度磁分离复合工艺,在实验中对实际废水处理进行了深入研究,为此技术废水处理工艺过程的开发和应用研究提供技术储备。研究中先对待处理污水中取的活性污泥进行磁场驯化、培养和分离纯化,利用所得菌群,对磁场强化生物降解过程进行了详细的实验研究。确定了三种废水(合成废水、青年湖水和卫津河水)的最佳降解条件,包括降解时间、磁感强度、温度、pH值、初始CODCr浓度等。另外,分析认为磁场对物质能量变化、自由基反应、生物体内酶活性、生物膜通透性的影响是磁场强化生物降解的机理。在高梯度磁分离实验中,利用自制高梯度磁分离器,考察了不同镍丝形式、磁感强度、镍丝填充率、液体流速、温度和填料使用次数对分离的影响,研究表明,镍丝与水流方向平行时处理效果最好,温度对分离没有影响,磁感强度越大、流速越小、镍丝填充率越大、使用次数越少分离效果越好。另外,通过对细菌或悬浮物在高梯度磁场中的受力计算和分析,确定其被分离出来所需要的最小磁感强度为188Gs。细菌在磁场中运动时会产生感应电流,电流达到一定阈值会使细胞破坏,或者改变离子通过细胞膜的途径,使蛋白质变性及破坏酶的活动。最后根据此前得到的最佳操作条件:强化阶段为磁感强度200Gs处理48h,分离阶段为磁感强度6000Gs、流速4.25 cm/min、镍丝12.0%处理7d,应用复合工艺连续处理实际废水。实现出水CODCr16.38mg/L ,总磷0.047 mg/L ,达到国家地表水环境质量Ⅲ类标准,满足非人体接触游乐区的水质要求,符合景观娱乐用水C类标准。更多还原

【Abstract】 Water is the source of life on earth and the only irreplaceable natural resources. With the rapid development of economy, water pollution and environmental deterioration had been seriously constrained the development of our country, protection and effective management of water have become the most serious challenges of our country.As a strengthen measure of sewage treatment technology, the coupling of magnetic technology with activated sludge, anaerobic fluidized bed technology and artificial ecosystems, in practical applications achieved gratifying results.In order to explore the mechanism of magnetic fields enhanced degradation and apply magnetic technology for the next step in wastewater treatment, in this paper Magnetic Fields Enhanced Biodegradation-High Gradient Magnetic Separation (shorted by MFEB-HGMS) complex process is initiated. The treatment scheme is discussed and probed in detail, in which the magnetic field can enhance the degradation efficiency of microbion in the actual wastewater treatment. This research gives firsthand data supporting the consequent research of the development and application of the magnetic field technology in waste water treatment process.In the research, the activated sludge taken from the sewage is acclimated and cultivated in magnetic field, and then isolated and purified. By mixed bacterium, the magnetic field enhanced biodegradation process carried out in a detailed experimental study. Three wastewater samples which come from: Synthetic sewage, Qing Nianhu and Wei Jinhe are studied.The optimum biodegradation conditions for wastewater such as time, intensity of magnetization, temperature, pH and initial concentration of CODCr, are confirmed. In addition, theoretical analysis finds that the influence of the magnetic field about the changes of material energy, free radical reaction, enzyme activity and biofilm permeability will be the mechanism of magnetic enhanced biodegradation.Separation of bacteria and suspended substance from waste liquid was studied using high-intensity high-gradient magnetic separator with nickel wires. The result indicates that the higher the magnetic field strength and the longer the duration, the better separation effect.The optimum separation conditions for the wastewater such as the different forms of nickel wire, magnetic induction, packed ratio of nickel wire, liquid flow rate, temperature and reuse frequency of nickel wire are confirmed. The result also indicates that the treatment effect is the best when the nickel wire paralleled the direction of water flow, the temperature has no impact on the separation, the higher the magnetic induction, the slower the velocity , the greater packed ratio of nickel wire, the fewer reuse times, the better separation effect. In addition, calculation and analysis find that it needs 188Gs to separate the bacteria or suspension in the high gradient magnetic separator. There will be induction current in the bacteria triggered by electromagnetic induction. When the current reached a certain threshold it will damage cells, change the way that ions through the cell membrane or denature protein, and then bacteria won’t be survived.At last, the actual wastewater is treated by the MFEB-HGMS comprehensive technology continuously under the optimum operation condition. Wastewater is treated in the enhanced stage for 48 hours with 200Gs and in the separation stage for 7 days with 6000Gs, 4.25cm/min and packed ratio of nickel wire is 12.0%. Use the MFEB-HGMS processes.The quality of purified liquid is CODCr16.38mg/L and TP 0.047 mg/L, which meet theⅢcategory of the state environmental quality standards for surface water and C standards of water quality standard for scenery and recreation area.更多还原