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活性污泥模型的发展及在SBR工艺中的应用 总被引:1,自引:0,他引:1
概述了活性污泥模型(ASM)的发展,对比了ASM各人模型对污水处理反应过程的理论描述。介绍了ASM在SBR工艺中的应用,这些研究表明,应用ASM进行系统的模拟和状态的调整可以辅助SBR工艺的设计,提高污水处理系统的处理效果。但是,由于模型本身和我国实际情况之间存在的问题,应用这些模型仍然有很多困难。 相似文献
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聚糖菌(GAOs)作为强化生物除磷(EBPR)系统中重要的微生物组成部分,具有反硝化脱氮的作用,但目前国内外关于GAOs的富集培养及反硝化代谢机理的研究尚不完善。综述了GAOs的种群类型以及反硝化聚糖菌(DGAOs)的代谢机理,着重归纳了碳源、pH、温度等因素对GAOs富集生长的影响,并在此基础上,对GAOs的研究现状及其研究方向进行了总结和展望,以期对GAOs的生理性能及强化生物除磷系统的稳定运行提供理论参考。 相似文献
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废水强化生物除磷(EBPR)系统中,聚磷菌(PAOs)是主要的除磷微生物,其中Accumulibacter是目前公认的主要一类PAOs,含有多个进化枝,且代谢特性存在差异。虽然PAOs尚无法独立培养,但可以在某些条件下选择性富集某一类进化枝的Accumulibacter。对废水EBPR系统内检测到的Accumulibacter具体分枝及其富集的条件进行了总结,并归纳了不同分枝的代谢特性;还分析了Accumulibacter主要分枝与其它菌群在EBPR系统中的相互关系,可为深入了解废水生物除磷微生理生态学、解决同步脱氮除磷污水处理系统的除磷性能恶化、出水水质波动等问题提供支持。 相似文献
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探究了新污染物利巴韦林(RBV)对强化生物除磷(EBPR)的影响,构建了强化生物除磷系统,分析了RBV浓度对EBPR的影响行为,并揭示了相关作用机制。结果证实RBV对EBPR的影响具有剂量依赖性,低于0.05 mg/L RBV对EBPR影响不明显,而超过0.1 mg/L RBV降低了除磷性能,在3.0 mg/L RBV组别内,COD和溶解性磷酸盐(SOP)去除效率分别下降至80.2%~84.1%和71.3%~75.6%。高浓度RBV降低了污泥浓度及有机质占比。短期内,高浓度RBV促进了胞外聚合物的分泌,但长期暴露发下RBV降低了EPS含量并主要降低了蛋白质和多糖含量。RBV能降低EBPR系统内胞内聚合物聚羟基脂肪酸酯(PHA)含量,进而后续产能不足降低除磷效率,但高浓度RBV刺激了糖原质的代谢。酶活性分析表明高浓度RBV降低了多聚磷酸盐激酶(PPK)和外切聚磷酸酶(PPX)的活性。研究结果为EBPR处理含RBV的废水提供一定的数据支撑和理论依据。 相似文献
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A full second-order moment(FSM) model and an algebraic stress (ASM) two-phase turbulence model are proposed and applied to predict turbulent bubble-liquid flows in a 2D rectangular bubble column.Predication gives the bubble and liquid velocities,bubble volume fraction,bubble and liquid Reynolds stresses and bubble-liquid velocity correlation.For predicted two-phase velocities and bubble volume fraction the is only silight difference between these two models,and the simulation results using both two models are in good agreement with the particle image velocimetry(PIV) measurements.Although the predicted two-phase Reynolds stresses using the FSM are in somewhat better agreement with the PIV measurements than those predicted using the ASM,the Reynolds stresses predicted using both two models are in general agreement with the experiments.Therefore,it is suggested to use the ASM two-phase turbulence model in engineering application for saving the computation time. 相似文献
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Here, we present the main features of human acid sphingomyelinase (ASM), its biosynthesis, processing and intracellular trafficking, its structure, its broad substrate specificity, and the proposed mode of action at the surface of the phospholipid substrate carrying intraendolysosomal luminal vesicles. In addition, we discuss the complex regulation of its phospholipid cleaving activity by membrane lipids and lipid-binding proteins. The majority of the literature implies that ASM hydrolyses solely sphingomyelin to generate ceramide and ignores its ability to degrade further substrates. Indeed, more than twenty different phospholipids are cleaved by ASM in vitro, including some minor but functionally important phospholipids such as the growth factor ceramide-1-phosphate and the unique lysosomal lysolipid bis(monoacylglycero)phosphate. The inherited ASM deficiency, Niemann-Pick disease type A and B, impairs mainly, but not only, cellular sphingomyelin catabolism, causing a progressive sphingomyelin accumulation, which furthermore triggers a secondary accumulation of lipids (cholesterol, glucosylceramide, GM2) by inhibiting their turnover in late endosomes and lysosomes. However, ASM appears to be involved in a variety of major cellular functions with a regulatory significance for an increasing number of metabolic disorders. The biochemical characteristics of ASM, their potential effect on cellular lipid turnover, as well as a potential impact on physiological processes will be discussed. 相似文献