Characterization of nitrifying granules produced in an aerobic upflow fluidized bed reactor

Since nitrification is the rate-determining step in the biological nitrogen removal from wastewater, many research studies have been conducted on the immobilization of nitrifying bacteria. In this research, granulation of nitrifying bacteria in an aerobic upflow fluidized bed (AUFB) reactor in a nitrification process for inorganic wastewater containing 500 g/m³ of NH₄⁺-N was investigated. It was observed that spherical, pseudocubic and elliptical granules with a diameter of 346 μm were produced at the bottom of the reactor after 300 days. Denaturing gradient gel electrophoresis analysis revealed that Nitrosomonas-like bacteria were the dominant ammonia-oxidizing species in the granules. Many colonies of Nitrosomonas-like bacteria were found in the outer part of the granules based on the spatial distribution analysis by fluorescence in situ hybridization. By stepwise reduction of the hydraulic retention time, the ammonia removal rate of the AUFB reactor containing these nitrifying granules finally reached 1.5 kg-N/m³/day. Results suggested that the use of granules realizes the retention of a large amount of nitrifying bacteria in the reactor, which guarantees a highly efficient nitrification.     

生物活性炭滤池预处理微污染原水运行方式比较

在考察生物活性炭滤池不同运行方式对其处理效果的影响时，试验表明，下向流运行时滤池对各项污染指标的去除效果均优于上向流，但上向流的反洗周期比下向流更长，两种方式的选取要根据实际情况具体分析。     

气浮提取蛋白-UASB & SBR工艺处理淀粉废水

采用气浮提取蛋白 -UASB&SBR工艺处理淀粉废水 ,工程运行表明在进水SS、CODCr、BOD5分别为6 86 2mg/L、14 4 6 7mg/L、86 72mg/L的条件下 ,出水SS、CODCr、BOD5分别为 86mg/L、12 7mg/L、2 2 .5mg/L ,处理水质稳定达到《污水综合排放标准》(GB8978— 1996 )二级标准 ;同时在处理过程中能够制取蛋白饲料和沼气 ,具有显著的环境效益和经济效益     

二氯吡啶生产废水的处理应用研究

江西某化工厂采用高级氧化-厌氧-好氧-混凝处理相结合的主体工艺处理2,3-二氯吡啶生产过程中产生的废水。对工艺选择的依据、工艺流程、工艺参数及运行效果进行了介绍。运行结果表明,废水经该工艺处理后,出水水质达到《污水综合排放标准》(GB 8978—1996)的三级标准,达到当地污水处理厂进水水质要求。     

气固并流系统中弥散颗粒混合行为的研究

采用磷光瞩拉瞬态点源注入示踪技术，研究了气固并流系统中弥散颗粒的轴、径向混合行为，并引入二维扩散模型加以描述，收到了良好的效果。对在气固并流上行和下行系统中的研究进行对比表明：在两种系统中弥散颗粒的轴、径向混合行为类似．研究还给出了在实验条件下气固并流上行系统弥散颗粒的轴、径向Peclet数的关联式．     

UASB+CASS组合工艺处理啤酒废水工程实例

通过对啤酒生产制作废水特点的综合分析,结合原有污水处理站工艺及多家同类污水站的实践经验,提出采用UASB+CASS组合工艺处理啤酒废水。运行结果表明:出水COD、BOD5、SS、NH3-N均满足《啤酒工业污染物排放标准》(GB 19821—2005)一级标准,出水动植物油、阴离子表面活性剂满足《污水综合排放标准》(GB 8978—1996)一级标准,采用该组合工艺处理啤酒生产废水,在技术和经济上可行。     

Model of simultaneous denitrification and methanogenesis in an Upflow Packed‐Bed Biofilm Reactor: Nitrogen compounds' inhibition and pseudo two‐dimensional biofilm model

BACKGROUND: The modelling of simultaneous denitrification and methanogenesis (DM) in upflow packed‐bed biofilm reactors (UPBR) and the effect of inhibition by nitrogen compounds on methanogenesis has received little attention. This study evaluated the effect using a model that incorporates a pseudo‐two‐dimensional biofilm model. RESULTS: The model was validated through comparison with experimental data, and achieved deviations below 5% for the liquid and gas phases. The model indicated that biomass stratification exists throughout the reactor and within the biofilm interior. At C/N ratios close to the stoichiometric C/N ratio, the process achieves efficiencies greater than 70% for nitrogen load rate (NLR) < 270 mg NO₃^?‐N dm^?3 h^?1. At high C/N ratios (50 mg total organic carbon (TOC) mg^?1 NO₃^?‐N), the process achieves efficiencies greater than 70% for organic load rate (OLR) < 83 mg TOC dm^?3 h^?1. CONCLUSION: The inclusion of the inhibition of methanogenesis by nitrogen compounds did not improve the predictions. Indeed, mass transfer in the biofilm was the phenomenon that most influenced the process. At C/N ratios close to the stoichiometric C/N ratio, process efficiency depends on the NLR; while at high C/N ratios, process efficiency depends on the OLR. Copyright © 2008 Society of Chemical Industry     

Experimental Investigation of Pressure Drop Hysteresis in a Cocurrent Gas–Liquid Upflow Packed Bed

Extensive experimental work on hysteresis in a cocurrent gas–liquid upflow packed bed was carried out with three kinds of packings and the air–water system. However, only when packed with small glass beads (f1.4 mm) was the bed pressure drop hysteresis observed. Two more liquids with different liquid properties were employed to further examine the influence of parameters on pressure drop hysteresis. The similarity of pressure drop hysteresis in packed beds was concluded in combination of experimental evidence reported in literature.     

钢厂污水的斜窄流沉渣除油设备

阐述了斜窄流沉渣浮油过程与原理，设备结构与材质，以及在钢厂污水处理中的应用及前景，其单位占地产能，为普通重力沉降设备的4倍，斜板或斜管设备的2倍，提出了深度净化少部分出水以防微细渣或油恶性积累，及充分及污水所含铁皮渣吸附油的必要与可能性。     

果汁废水处理技术的研究进展

果汁加工废水属于高浓度有机废水,具有固体杂质多、有机物浓度高、水质水量变化大等特点。相对于酒精废水、淀粉废水、印染废水、造纸废水等其他高浓度有机废水,对果汁废水的处理技术的研究有些滞后。目前国内外关于果汁废水处理的相关研究和工程实例报道较少。作者主要对果汁废水处理工艺进行系统的总结。