Research On The Advanced Treatment Of Tetracycline Wastewater By Catalytic Oxidation Technology

China has become a global power of the production of pharmaceutical raw materials, while the rapid development of pharmacy industry leads to the severe environmental pollution increasingly which results from the release of "Three wastes".In this study,Various weight percentages of zero valent iron particles ?NZVI? were impregnated into the framework of zeolite X to synthesize a series of novel magnetic zeolites ?n?FeX, which were applied to remove teracycline?TC? from water. The result showed that:?l?as the weight percentage of NZVI increased, the aluminum in the framework of zeolite was substituted by iron while the content of sodium ions increased. The TC removal efficiency of ?n?FeX samples enhanced as the weight percentage of NZVI increased ?0-5%?. As the weight percentage of NZVI was 5%, the TC removal efficiency of ?n?FeX was maximum which reached 97%. ?2?The TC removal effciency decreased as the pH of TC solution increased. ?3?The TC adsorption isotherms were fitted well by the Langmuir model. The adsorption kinetics were well described by pseudo-second order equation. It was speculatd that the ?n?FeX can combine with TC mainly through the way of electrostatic adsorption and cation exchange.During the study, the photocatalytic oxidation effects of TC by two catalysts which were silver-halide photocatalytic system ?Ag-?0.05? FeX? and the silver-titanium dioxide ?Ag-TiO2? were compared at the xenon lamp ?500W? light. The result showed that:?1?When the concentration of the catalyst Ag-?0.05? FeX was 1 g·L^-1 and the pH value of TC solution was 3, the removal rate of TC was maximum which reached 85%. ?2?When the catalyst Ag-?0.05?FeX was added at lg/L and the pH value of TC solution was 6, the removal rate of TC was highest which was obtained at 60%. ?3?Ag-?0.05? FeX was utilized as a catalyst for advanced treatment of pharmaceutical wastewater which has been treatment by A-A-O biological treatment process. The result showed that when the CODcr concentration of wastewater was around 200-600 mg·L^-1, the CODcr and the ammonia concentration could be stabilized at 80-100 mg·L^-1 and 10 mg·L^-1 respectively after the photocatalytic process, the photocatalytic degradation rate of CODcr was about 80%.