【作者】 杜飞；

【导师】 张爱丽；

【作者基本信息】 大连理工大学 ， 环境工程， 2011， 硕士

【摘要】 膜萃取是膜过程和液-液萃取相结合的一种新型萃取分离技术。该技术具有效率高、能耗低、过程简单、运行稳定等优点。生物法是污水处理中应用最广、最为经济的方法。它具有效率高、工艺操作管理方便、运转维护费用低等优点,目前己成为环境污染治理与控制中最为常用的技术。但对于高盐有机废水,高盐度和极端环境条件使得微生物难以生存,生物法的应用受到限制。基于膜萃取技术和生物处理法各自在水处理领域的优点——膜分离的高效性和生物降解的经济性,本文构建了萃取膜生物反应器,以水杨酸为目标污染物,开展了膜萃取分离／生物降解处理高盐水杨酸废水的膜传质特性和生物降解特性研究。主要的研究工作：(1)水杨酸的生物降解研究。对水杨酸降解菌进行了驯化培养,考察了不同盐度对菌降解水杨酸的影响。实验表明：盐度达到60 g/L时,水杨酸降解菌不能生存。(2)高盐水杨酸模拟废水的渗透萃取研究。探讨了进水流量F、运行温度T、萃取液pH值、料液进水浓度Cf,in等操作条件对膜传质特性、水杨酸去除效果和水杨酸回收特性的影响。实验表明：总传质系数Kov随进水流量的增大而近似呈指数关系上升,随运行温度、萃取液pH值、料液初始浓度的增大而升高。膜阻是影响传质的决定因素,Kov的数量级均为10-7m/s。在Cf,in=854.2±19.7 mg/L、F=3 L/d、T=323 K、萃取液侧pH=11.5±0.2、膜管长L=50 m的条件下,水杨酸去除率达到97%。膜萃取过程中,各操作条件下膜管中有不同量的水杨酸残留,水杨酸回收率在40～145%之间。(3)萃取膜生物反应器处理高盐水杨酸模拟废水的研究。在适宜生物生长的条件下,改变料液进水浓度Cf,in,考察了膜传质特性和生物降解特性。实验表明：随着进水浓度的不断降低,传质推动力不断减小,总传质系数Kov整体上呈现下降趋势。反应器生物相中经过27 d的培养,膜管外壁上的生物膜逐渐形成。生物相中微生物在适宜的环境条件下可以充分利用透过膜的水杨酸,生物相中水杨酸浓度基本维持在18.7+6.0 mg/L之间。(4)萃取膜生物反应器和膜萃取反应器传质特性的对比。与膜萃取反应器相比,在温度和进水流量相同而pH不同的操作条件下,萃取膜生物反应器中总传质系数Kov在不同进水浓度下有不同程度的提高,萃取膜生物反应器中的膜传质性能优于单独的膜萃取反应器。更多还原

【Abstract】 Membrane extraction is a new separation technology which combines membrane process with liquid-liquid extraction. It has advantages in high efficiency, low energy consumption, simple process, stable running, and so on. Biological process is the most widely used and economical technology in the treatment of wastewater. It has advantages in high efficiency, simpleness and conveniency in operation and management, low cost in maintenance. It has been to the most widely used technology in the treatment and control of environmental pollution. But for the hyper-saline organic wastewater, it is hard for microorganisms to survive under the conditions of high salinity and extreme environment. The application of biological process is limited. Based on the respective advantages of membrane extraction and biological process in the field of wastewater treatment, high efficiency in membrane separation and economics in biological process, an extractive membrane bioreactor was constructed. Salicylic acid (SA) was chosen to be the target compound. The research on a new treatment process that a membrane separation combined with biodegradation was carried out. The characteristics of membrane mass transfer and biodegradation were investigated. The following studies were carried out:(1) The research on biodegradation of SA. SA-degrading bacteria were acclimated by serial batch culture. The effects of salinity on biodegradation of SA were investigated. The results showed that:If the salinity came to 60 g/L, the SA-degrading bacteria can not survive.(2) The research on membrane extraction of hyper-saline SA simulation wastewater. In the membrane extraction reactor, the effects of influent flow rate, system temperature, pH in the stripping solution and initial SA concentration in the influence on mass transfer process, the SA removal efficiency, and the SA recovery efficiency were investigated. The results showed that:The Kov is exponentially related to influent flow rate. And Kov increased as the influent flow rate, system temperature, pH in the stripping solution or initial SA concentration increased. Membrane resistance was determined to be the major factors affecting mass transfer process. The order of magnitude of Kov was 10-7 m/s. Around 97% SA removal was obtained under conditions of influent SA concentration of 854.2±19.7 mg/L, flow rate of 3 L/d, system temperature of 323 K, pH of 11.5±0.2 in the stripping solution and membrane length of 50 m. In the membrane extraction process, different amounts of SA residues were left in the membrane under different operating conditions. The SA recovery efficiency was basically between 40～145%.(3) The research on treatment of hyper-saline SA simulation wastewater in an extractive membrane bioreactor. Under appropriate conditions for microorganisms to grow, influent SA concentration was changed to investigate the characteristics of membrane transfer and biodegradation. The results showed that:With the continuous decrease of influent SA concentration, the mass transfer driving force decreased, and Kov mainly showed a downward trend. After 27 d of cultivation in the biological zone in the reactor, the biofilm gradually formed on the outside of membrane tube. SA extracted through the membrane was effectively utilized by microorganisms in the biological zone under appropriate environmental conditions. The SA concentration in the biological zone was basically maintained at 18.7±6.0 mg/L.(4) The research on contrast of the characteristics of membrane transfer between the extractive membrane bioreactor and the membrane extraction reactor. Compared with the membrane extraction reactor, under the same system temperature and influent flow rate, but different pH conditions, Kov in the extractive membrane bioreactor increased in different degrees as different influent SA concentration. The mass transfer process in the extractive membrane bioreactor was better than that in the membrane extraction reactor.更多还原