| Veterinary antibiotics were not only helpful to disease prevention and treatment but also helpful to growth. They were widely used in large scale and intensive animal husbandry industry. At present, the phenomenon of abuse antibiotics was very serious, so that antibiotics residual content in livestock meat and egg exceeded the standard. Only 30% ~ 70% antibiotics were used in body, the remaining entered surrounding water, soil and other environmental media with the waste. Compared with other pollutants, content of antibiotics was very low. But lasting exposure and difficult biodegradable properties made antibiotics producing continuing potential environmental risk to water, soil and biology. The conventional treatments of antibiotics included activated carbon adsorption method, membrane filtration method, the conventional activated sludge process(conventional activated sludge, CAS), membrane bioreactor(membrane bioreactor, MBR), and so on. Activated carbon adsorption method and membrane filtration method could not really remove antibiotics in the environment. The removal antibiotics effect of common activated sludge was general. MBR combined biological treatment technology with membrane separation technology, and separate control of hydraulic retention time(hydraulic retention time, HRT) and sludge retention time(sludge residence time, SRT) to obtain longer sludge age, keep generation bacteria and obtain a better antibiotics removal effect. The Yangtze River Delta Region was an important pig breeding base. Its water quality was poor because of aquaculture industry and upstream drainage. Little was known about removal effect of veterinary antibiotics in treating swine wastewater in MBR, and antibiotic removal pathways. The aim of this study was to research removal characteristics of veterinary antibiotics in treating swine wastewater in intermittent membrane bioreactor.Method of solid phase extraction and high performance liquid chromatography-tandem mass spectrometry was developed in order to determine eleven commonly used veterinary antibiotics(including four tetracyclines, two sulfonamides, three quinolones and two macrolides) of wastewater and activated sludge in the Yangtze River Delta Region. The research adopted intermittent aeration membrane bioreactor(IAMBR) to treat swine wastewater, and was focus on different conditions of HRT, SRT to affect removal antibiotics rates and accumulation contents of sludge. Mass balance was used to know the antibiotics removal ways and removal ratio. Shake flask test analyzed degradation activity influence of TOC and ammonia nitrogen by the presence of antibiotics in sludge.The results showed that the optimized SPE-HPLC/MS/MS method, which was applicable to test 11 antibiotics in swine wastewater and sludge, was low detection limit and high sensitivity; HRT was through changed organic load to affect antibiotics removal. SRT and COD/TN were not the important influence factors of antibiotics removal. Sludge accumulations of tetracycline, sulfonamide antibiotics were related to longer SRT. Content and composition of antibiotics in water impacted greatly antibiotics in sludge; Mass balance showed that tetracycline antibiotics mainly removed by adsorption and degradation, sulfonamide antibiotics removal mainly relied on degradation; Shake flask test showed there was no obvious influence in degradation of TOC and ammonia nitrogen in current antibiotics pollution level of activated sludge. |
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