投加微粉强化低浓度生活污水活性污泥好氧颗粒化

以教工生活区实际生活污水为底物,考察了分别投加硅藻土和粉末活性炭对活性污泥好氧颗粒化的强化作用。结果表明:硅藻土和粉末活性炭均能有效缩短好氧颗粒污泥形成时间;投加硅藻土、粉末活性炭形成的颗粒污泥外观及内部细菌种类存在明显差别,投加微粉会降低好氧颗粒污泥中微生物种群的多样性,相对于硅藻土粉末活性炭更适于微生物附着生长;未投加微粉和投加硅藻土的反应器处理污水的效果较差;投加粉末活性炭的反应器在快速形成好氧颗粒污泥的同时还能保留更多生物量,对COD、NH_4~+-N的去除率分别为85. 3%和87. 2%。当处理低浓度生活污水时,投加粉末活性炭是促进活性污泥好氧颗粒化的有效策略。     

SBR中好氧颗粒污泥的培养与除污效能

以普通絮状活性污泥为种泥，采用人工配水，通过控制运行条件在SBR中成功地培养出了好氧颗粒污泥。研究表明，该好氧颗粒污泥具有良好的同步硝化反硝化和去除COD的性能。好氧颗粒污泥成熟后平均直径为4～5mm，沉速为72～90m／h，反应器中MLSS为7．8g／L，使反应器对COD和NH3-N的去除率分别达到了95％～98％和75％～90％。     

污泥接种量对复合生物膜反应器启动的影响

为实现复合生物膜反应器的快速启动,采用4种污泥接种量,分别在4个反应器中进行平行试验。结果表明,污泥接种量最大的反应器和采用快速排泥法反应器的启动时间并非最短,而最佳接种量的反应器仅12 d就可成功启动,与其他三个反应器相比,其生物膜的微生物活性最好,对COD、NH3-N的去除效果最佳,去除率分别为93%和100%,生物膜的生物量为1.2 g/L,生物膜平均厚度和微生物活性分别稳定在约290μm和58 mgO2/(gMLSS.h)。因此,在启动复合生物膜反应器时,控制合理的污泥接种量,可以在悬浮污泥微生物和生物膜微生物之间形成有效的竞争关系,有助于形成良好的生物膜结构和加快启动过程。     

铁碳微电解填料对好氧污泥颗粒化的强化作用

好氧颗粒污泥难以快速、稳定形成是限制其大规模工程化应用的重要原因,鉴于此,以大学校园生活区污水为底物,利用序批式反应器（SBR）研究了投加铁碳微电解填料对好氧污泥颗粒化的强化作用。结果表明,铁碳微电解填料能提高活性污泥的沉降性、有效缩短好氧颗粒污泥的形成时间,同时铁碳原电池反应生成的惰性碳粒晶核有助于更多世代时间较长的微生物（硝化菌）附着生长。投加铁碳微电解填料是实现铁碳微粉缓释、强化好氧污泥颗粒化的有效策略。     

低温好氧颗粒污泥反应器的启动特性研究

好氧颗粒污泥技术具有良好的应用前景,但是当温度波动较大时颗粒污泥会发生解体,因此研究低温好氧颗粒污泥反应器的运行对推动好氧颗粒污泥技术的发展具有重要意义。研究了低温条件下好氧颗粒污泥反应器的启动过程及其特性,结果表明:经过约40 d的培养,形成了沉降性能良好和生物量较高的好氧颗粒污泥。污泥胞外聚合物内蛋白质类物质含量提高了1.8倍,蛋白质类物质浓度的升高与稳定存在是絮状活性污泥颗粒化的重要因素。低温好氧颗粒污泥对生活污水中的污染物具有较好的去除效能,但是其反硝化效果较差,反应器内溶解氧含量较高以及反硝化细菌与聚磷菌对外碳源的竞争劣势是造成硝酸盐氮积累的主要原因。红外光谱分析结果显示絮状污泥颗粒化之后,污泥的主要官能团没有发生变化,污泥性质稳定。胞外聚合物内蛋白质类物质和溶解性微生物产物的荧光强度升高,表明低温好氧颗粒污泥的强度增加,颗粒污泥内部结构更加稳定,污泥微生物对低温的适应性逐渐加强,污泥活性提高。     

基质匮乏对好氧污泥颗粒化的影响研究

分别采用人工模拟废水和实际生活污水接种污泥指数为51mL/g的普通活性污泥,并在SBR反应器中培养好氧颗粒污泥,反应器的运行周期为4h、表面气体流速为3.48cm/s。结果表明,在前72个周期的运行中,反应器的出水COD浓度均较高,即模拟废水系统的出水COD100mg/L、生活污水系统的出水COD200mg/L,反应器内均没有出现基质匮乏现象。运行72个周期后,反应器内形成了粒径为0.1～0.3mm的好氧颗粒污泥。由此可见,基质匮乏并不是好氧颗粒污泥形成的必要条件。     

序批式生物膜反应器的生物膜特性研究

通过扫描电镜对具有除磷功能的序批式生物膜反应器中生物膜的形态结构进行了观察，并考察了容积负荷、曝气量和厌氧循环水量对生物膜量的影响。结果发现，生物膜主要由微生物及其胞外多聚物组成，大量的微生物及其胞外多聚物相互连结，形成稳定的缠结结构。平均每片填料上附着的生物膜质量为4．088g，挥发性生物膜质量与生物膜干质量的比值为0．861，表明活性生物量较高。填料上的生物膜量主要受曝气量和厌氧循环水量的影响，而容积负荷对填料上的生物膜量基本没有影响。     

SBR中生物膜促进好氧颗粒化研究

利用弹性填料附着生物膜,在选择压法培养好氧颗粒污泥(AGS)的过程中研究人工刮膜使其进入混合液对好氧颗粒化进程的影响。前23 d内颗粒化率随着生物膜刮落进入混合液中而不断增加,24 d后将弹性填料上附着的生物膜全部刮入混合液中,颗粒化率大幅度提高。游离态生物膜在颗粒化过程中发挥了前驱物或晶核作用,而在较高水力选择压下微生物分泌的胞外聚合物促进了松散的生物膜转化为结构密实的AGS,因而在冬季较低温度下于30 d内成功实现了好氧颗粒化。弹性填料有效地提高了系统的稳定性,即使选择压法操作不当时仍可以抵抗污泥膨胀造成的影响,这一设置有效地降低了系统崩溃的风险。运行过程中反应器表现出较好的污染物去除效果,对COD、TIN及TP的去除率常在90%、82%及80%以上。     

厌、好氧周期循环下的污泥颗粒化过程

为研究厌氧／好氧周期循环条件下厌氧快速吸收工艺中的污泥颗粒化过程、成因及影响因素，分别采用葡萄糖、乙酸钠人工配水及实际城市污水进行了试验。结果发现，形成的好氧颗粒污泥呈球形或椭球形，致密且边界清晰，其中葡萄糖配水的污泥粒径为0．5～0．8mm，最大可达1．0mm，SVI值为25～30mL／g；乙酸钠配水的污泥粒径为0．2～0．4mm，SVI值为40mL／g左右；实际城市污水的污泥经过短期运行即开始出现小颗粒，SVI值为60mL／g左右。3种污泥均具有良好的厌氧COD吸收活性。     

树脂载体厌氧附着膜膨胀床的启动及运行研究

采用载体吸附法培养高活性的厌氧生物膜颗粒,并对反应器的启动及运行进行了研究,探索用生物膜颗粒取代厌氧颗粒污泥的可行性.试验以树脂为载体,用厌氧附着膜膨胀床(AAFEB)处理高浓度有机废水,经过启动、中等负荷稳定运行及高负荷稳定运行等阶段,成功地培养出高效生物膜颗粒,反应器仅需24 d就可完成启动,最高容积负荷达到了46 kgCOD/(m3·d),对COD的去除率为80%～95%.     

生物活性炭滤池初期运行效果评价

结合相城水厂活性炭滤池的初期投运过程,研究了生物膜的自然生长情况及其对水中有机污染物的去除效果.通过对比气、水反冲和单水冲两种模式的实际效果,探讨了不同冲洗方式对生物膜恢复净水效果的影响.结果表明:环境温度偏低和较好的水质将在一定程度上延长炭粒表面的自然挂膜速度,生物膜一旦有效形成,可在常规净水工艺基础上进一步提高对氨氮、耗氧量和TOC等指标的去除效果,切实保证出厂水的生物稳定性.     

Modelling the consumption of dissolved contaminants by biofilm periphyton in open-channel flow

An analytical model of the decrease in dissolved contaminant concentration in an open channel flow through the consumption by a botton biofilm is presented. This idealized model considers the flux of the contaminant by diffusion through the concentration boundary layer into the biofilm, with diffusion and reaction within the biofilm. Solutions for zero-order as well as first-order kinetics are derived which show that the rate of change of the concentration in the main flow is directly related to the kinetics in the biofilm. The thickness of the concentration boundary layer is shown to have a significant influence on the rate of decrease of concentration in the main flow.     

Effect of turbulence on nitrifying biofilms at non-limiting substrate conditions

The effect of turbulence on nitrifying biofilms was studied in five cylindrical PVC (polyvinyl chloride) reactors, each having ten biofilm sampling taps, over a period of 196 days. Bulk water in the reactors was stirred by paddles at 32, 92, 140, 278 and 500 rpm and the turbulent intensities measured at 10 mm from the wall were 0.6, 1.5, 2.6, 4.4 and 8.9 cm/s. Biofilms appeared as isolated colonies and continued to grow as filament-type biofilms. Higher turbulence resulted in higher NH₄-N flux and higher areal biomass density. Turbulent diffusion of substrates and by-products in the vicinity of filament-type biofilms must have resulted in the above phenomena. Photographic observation of the biofilm surfaces on sampling taps showed uniform biofilm filaments at higher turbulent intensities and large variation in the height of filaments at low turbulent intensities. Substrate flux and biofilm structure (areal density, filament height and cross-sectional area of filament) are inter-related parameters and are strongly affected by turbulence near the biofilm. Substrate flux is expressed as a power function of turbulent intensity, volumetric density and substrate concentration for filament-type biofilm when substrates are non-limiting.     

Methanogenic bacteria adhered to solid supports

Adhesion of methanogenic bacteria and acidogenic bacteria to solid supports has been studied by using various solid materials. Three kinds of bacteria slurries were prepared for the experiments. These were cultured by feeding them acetic acid, an acid mixture and a mixture of glucose and pepton respectively. Test specimens were submerged into the bacteria slurries for different periods of time. The overall process of biofilm development was divided into 3 phases: induction, accumulation and dynamic balance between production and shearing. The quantity of adhered biomass varied with the characteristics of the solid supports. Bacteria adhered to the moderately rough surfaces that have pores measuring a few tenths of a micron in diameter more than the polished surfaces and rough surfaces and preferably adhered to the solid supports made of carbon material. The formation of the biofilm depends not only on the characteristics of the bacteria and fluid regimes but also on the characteristics of the solid supports.     

pH-decrease in nitrifying biofilms

Nitrification is an acidity producing process. It has been shown theoretically that the diffusional resistance to the transport in the biofilm of the inorganic carbon species as affected by the acidity production in a nitrifying biofilm gives rise to a decreased pH in the interior of the biofilm. These theoretical results have been verified on biofilms developed on the surfaces of a rotating drum under well controlled laboratory conditions. The results show clearly the drop in pH as predicted by theory. The phenomenon can give rise to unexpected effects on the performance of nitrifying biofilms, when most of the bacteria work under a much lower pH than the pH measured in the bulk water.     

Characterization of biofilm through an inhibitive kinetic function

Several results have been obtained for biofilm under inhibitive substrate. The first result gives the conditions that the existence of protective effect in biofilm depends on the bulk liquid substrate concentration. The second adds one boundary condition to obtain a biofilm thickness such that the whole range of biofilm has higher substrate consumption rates than the rate in the bulk liquid. The third shows the maximum range of two intervals for both substrate concentration at the wall and biofilm thickness, and equations for two conservative biofilm thicknesses that may be useful for practical applications.     

生物砂滤池不同挂膜方法的试验研究

根据生物砂滤池的运行特点，通过试验对自然挂膜和接种挂膜两种不同挂膜方法下，各滤柱中的生物量和生物活性，对CODMn、NH4^＋ -N和UV254的去除效果以及运行周期进行了分析研究。结果表明，接种挂膜的启动时间比自然挂膜缩短了6～8d，同时生物量较多，但生物活性比自然挂膜法低12．03％～14．29％；各柱对CODMn、NH4^＋ -N均有很好的去除效果，平均去除率在35％和80％以上；但采用自然挂膜法对污染物的去除效果更佳，特别是对UV254的去除率较接种挂膜法提高了5．01％～10．8％，并且运行周期延长了6～10h，运行更为稳定。     

下水道污水处理研究进展及展望

下水道在水污染控制系统中一直扮演着污水收集及输送的角色,并且对下水道的相关研究也处于"黑箱"状态。随着人们环保意识的增强以及科学研究手段和测试技术的发展,对下水道的研究逐渐成为水污染控制领域的热点之一,但时至今日仍未形成系统的理论与技术。介绍了国内外研究者对下水道处理污水方面的研究现状,并从"排水管道作为反应器"的视角出发,针对今后下水道处理污水需要开展的研究工作提出了展望。     

MBBR和传统活性污泥法组合的BAS工艺

介绍了MBBR移动床生物膜和活性污泥组合工艺（BAS工艺），该工艺可处理进水COD较高或营养物缺乏的污水，占地省、运行稳定、污染物处理效率高、可大幅度降低生物污泥产量和减少出水营养物的排放。     

Anaerobic fixed-film reactors treating carbohydrate wastewater

Anaerobic downflow stationary fixed-film reactors operated at 35°C, successfully treated synthetic (sucrose-based) wastewater of different concentrations at high organic loading rates and short hydraulic residence times. Waste stabilization was due to the high concentration of active biomass retained in the biofilm. Biofilm biomass concentration increased with organic loading rate reaching a maximum of 8.7 kg VFS m⁻³ of reactor volume (0.112 kg VFS m⁻² support surface). The biofilm was found to be completely active and unaffected by diffusional limitations up to an average thickness of 2.6 mm.