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膜孔参数及表面活性剂对微孔曝气器充氧性能的影响研究 总被引:1,自引:0,他引:1
《环境污染与防治》2015,(10)
污水处理厂曝气设备的性能及水质条件是影响曝气充氧性能的重要因素,比较了清水及不同表面活性剂浓度下橡胶膜曝气器的曝气充氧性能,以标准氧传质效率(SOTE)为评价指标,得出了不同工况及膜孔参数下曝气充氧性能的变化规律。结果表明:在清水条件下,SOTE随着通气量、膜孔间距、膜孔孔径的增大而降低;表面活性剂条件下的SOTE(αSOTE)随着表面活性剂浓度的增大而降低;修正系数(α,αSOTE与SOTE的比值)随着膜孔孔径的增大而增大,膜孔孔径越小,表面活性剂对橡胶膜曝气器充氧性能的抑制作用越大。 相似文献
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不同填料对反应器充氧能力影响的比较研究 总被引:3,自引:0,他引:3
填料是生物接触氧化工和进气量的情况下DO的变化,分析填料对曝气池DO的转移速率有无影响.实验结果表明:对悬浮式填料而言,选择合适的曝气量,投加率在一定的范围内时,随着投加率的增加,曝气池充氧能力增强;对悬挂式填料而言,弹性立体填料的放射状细条结构对气泡起到较强的切割作用,提高了充氧效率.曝气池充氧能力受填料投加率的影响程度顺序为:弹性立体填料>立体块式悬浮填料>内置悬浮球形填料>盾式填料. 相似文献
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以上海竹园第二污水处理厂2号生物好氧处理单元为研究对象,采用工艺状态曝气充氧性能测定仪对曝气器性能进行现场测定,通过核算氧利用率、曝气均匀性指数、曝气效率综合影响因子等指标,评价该厂曝气器日常运行状态,分析曝气系统在控制上的不足,并针对性地提出优化方案。结果表明,工艺状态下曝气器氧利用率与清水条件下相比下降19.22%~23.78%,曝气均匀性指数在0.80~1.34的范围内,曝气效率综合影响因子偏低,充分表明2号生物好氧处理单元部分曝气器存在污染或老化的问题。该厂的曝气系统具有较大的优化潜力,性能评价结果可以为曝气器科学管理维护及水厂的运行优化提供指导。 相似文献
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盘式曝气器是目前城市污水处理厂主要采用的曝气设备之一。但目前盘式曝气器存在充氧能力低、阻力损失大、使用寿命短等技术问题,增加了城市污水处理厂运行成本,降低了运行效能。针对这些问题,对盘式曝气器进行了结构优化设计。通过结构优化,既改善了曝气器的抗撕裂性和自闭性,同时叉提高了充氧能力,降低了曝气阻力损失。 相似文献
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低压供气式射流器工业化性能研究 总被引:1,自引:0,他引:1
简要介绍了低压供气式射流器的工作原理和作用,对其在氧化沟污水处理工艺中的氧利用率和动力效率等因素做了测试和分析,比较了不同水深对充氧性能的影响。结果表明,低压供气式射流曝气器氧利用率达23.17%,动力效率达2.43 kg O2/(kW.h),优于其他形式的曝气设备,可以有效降低能耗。 相似文献
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填料材质、结构等影响到生物膜的性状和水力学特性 ,是决定生物接触氧化工艺处理效果的关键因素。本文分别选取了悬挂式填料和悬浮式填料各 2种填料 ,分别从COD与NH3 N的去除、充氧效率和出水浊度等方面对各种填料处理城市污水进行了比较研究。实验结果表明 ,悬挂式填料具有挂膜快、处理效果稳定 ,受环境变化影响较小 ;悬浮式填料受气水作用能够悬浮转动而具有较强的布水、布气功能 ;生物量的差异导致悬浮式填料和悬挂式填料处理效果和充氧效率不同 ,悬浮式填料生物膜容易脱落导致系统受负荷冲击时生物量流失而处理效果变差 ;软性填料生物膜容易板结成球 ,容易导致其处理效果降低 相似文献
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针对分散填料曝气塔中多相流的流态与传氧过程,实验了布气方式以及海绵和陶粒2种填料对于体系的气含率εg、流态以及气-液传质性能的影响。在表观气速U范围(0.01~0.18 m/s)内观察到81孔布气板(Φ1 mm)体系出现3个明显相区,孔数过少(25孔),或者孔间距较小(225孔)均没有明显过渡区,在湍流区(U>0.118 m/s)3种布气板的气含率没有明显差别。海绵填料体积分数εs<25%时体系的气含率没有明显变化,35%时气含率下降且过渡区提前出现。在非均相区,海绵填料明显提高了体系的传质系数KLa。陶粒填料降低了气含率,固含率对εg的影响差别不明显,同时降低了多相流体系的KLa,且随着固含率的增加KLa降低。对比多种操作条件,单位体积空气传氧能力KLa/εg无明显差别,但在81孔布气板的过渡区KLa/εg出现一个明显的极小区间,说明过渡区传氧效率较低。在特定的实验操作条件下,KLa/εg较为稳定,这为深入理解两种气泡群体的共存体系在传氧性能方面各自的权重,提供了重要的量化参考。 相似文献
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Adama Ndao Balasubramanian Sellamuthu Jean R. Gnepe Rajeshwar D. Tyagi Jose R. Valero 《Journal of environmental science and health. Part. B》2017,52(9):623-630
Pilot-scale Bacillus thuringiensis based biopesticide production (2000 L bioreactor) was conducted using starch industry wastewater (SIW) as a raw material using optimized operational parameters obtained in 15 L and 150 L fermenters. In pilot scale fermentation process the oxygen transfer rate is a major limiting factor for high product yield. Thus, the volumetric mass transfer coefficient (KLa) remains a tool to determine the oxygen transfer capacity [oxygen utilization rate (OUR) and oxygen transfer rate (OTR)] to obtain better bacterial growth rate and entomotoxicity in new bioreactor process optimization and scale-up. This study results demonstrated that the oxygen transfer rate in 2000 L bioreactor was better than 15 L and 150 L fermenters. The better oxygen transfer in 2000 L bioreactor augmented the bacterial growth [total cell (TC) and viable spore count (SC)] and delta-endotoxin yield. Prepared a stable biopesticide formulation for field use and its entomotoxicity was also evaluated. This study result corroborates the feasibility of industrial scale operation of biopesticide production using starch industry wastewater as raw material. 相似文献
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《国际环境与污染杂志》2011,21(5):511-518
The purification capacity of the contact stabilisation system at Birzeit University campus has been studied for two years. The oxidation capacity of organic matter, ammonium oxidation, and denitrification potential were determined. The reduction of chemical oxygen demand (COD) was 85%, and the effluent COD concentration was less than 110 mg/l (the average value was 88 mg/l). Suspended solids were removed with equal efficiency. The aerobic stabilization of organic solids was efficient, and no excess biosolids (sludge) had to be removed. High nitrification (70% of the influent nitrogen were nitrified) could be maintained at 15°C, and 42% of the oxidised nitrogen was denitrified. The specific oxygenation capacity of the treatment system is relatively high and reached about 5 kwh/kg COD. The specific wastewater treatment cost is about 0.52 US$/m3 or about 58 US$ per population equivalent per year. Based on the results obtained, batch operation and intermittent aeration of the biological process are suggested to achieve high effluent quality and to reduce power consumption. 相似文献
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Majda Nashashibi-Rabah Christos Christodoulatos George P Korfiatis 《Water environment research》2005,77(2):138-145
Operation of aerobic biological reactors in space is controlled by a number of challenging constraints, mainly stemming from mass transfer limitations and phase separation. Immobilized-cell packed-bed bioreactors, specially designed to function in the absence of gravity, offer a viable solution for the treatment of gray water generated in space stations and spacecrafts. A novel gravity-independent wastewater biological processor, capable of carbon oxidation and nitrification of high-strength aqueous waste streams, is presented. The system, consisting of a fully saturated pressurized packed bed and a membrane oxygenation module attached to an external recirculation loop, operated continuously for over one year. The system attained high carbon oxidation efficiencies often exceeding 90% and ammonia oxidation reaching approximately 60%. The oxygen supply module relies on hydrophobic, nonporous, oxygen selective membranes, in a shell and tube configuration, for transferring oxygen to the packed bed, while keeping the gaseous and liquid phases separated. This reactor configuration and operating mode render the system gravity-independent and suitable for space applications. 相似文献
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Photoinductive activity of humic acid fractions with the presence of Fe(III): the role of aromaticity and oxygen groups involved in fractions 总被引:1,自引:0,他引:1
Relationship between the photoinductive activity and the properties of humic acids (HA) fractions were investigated with and without Fe(III). Three fractions were separated based on the molecular weight (M(w)) and were obtained following the order of M(w): F(A)>F(B)>F(C). Compared to F(A) and F(B), photodegradation of atrazine under simulated sunlight was much faster in solution containing F(C), whose structure was dominated by greater aromaticity, more oxygen groups and fluorophores. The interaction of HA fractions and Fe(III) was studied using fluorescence spectrometry and F(C) had the largest quenching constant. The capacity of electron transfer, estimated from the amount of photoformed Fe(II), was also highest for F(C). Thus, the Fe(III)-F(C) complex was efficient in phototransformation of atrazine in nearly neutral aqueous solutions. These results suggest that the aromaticity and oxygen groups content of HA exert great influence on the binding ability of metals and on the fate of pollutants in natural waters. 相似文献