EGSB反应器微氧颗粒污泥醛快速培养及其除污效能研究

常温条件下以生活污水为基质,采用EGSB反应器培养微氧颗粒污泥,考察了颗粒污泥的特性及其除污效能。结果表明,厌氧颗粒污泥经过逐步加氧驯化能培养出性能稳定的高活性微氧颗粒污泥,其结构密实,粒径集中在0．63～2mm,沉速为14～85m／h,同时具备产甲烷和脱氮能力;反应器出水COD低于50mg／L,去除率可稳定在90％以上;脱氮效果受溶氧条件和回流稀释的影响;水力停留时间为10h,反应器出水D0为0．2～0．3mg／L,回流比为10时,TN和NH—LN平均去除率分别达到81％和85％,平均出水浓度低至13．2mg／L和7．7mg／L。     

EGSB反应器微氧颗粒污泥醛快速培养及其除污效能研究

常温条件下以生活污水为基质,采用EGSB反应器培养微氧颗粒污泥,考察了颗粒污泥的特性及其除污效能。结果表明,厌氧颗粒污泥经过逐步加氧驯化能培养出性能稳定的高活性微氧颗粒污泥,其结构密实,粒径集中在0．63～2mm,沉速为14～85m／h,同时具备产甲烷和脱氮能力;反应器出水COD低于50mg／L,去除率可稳定在90％以上;脱氮效果受溶氧条件和回流稀释的影响;水力停留时间为10h,反应器出水D0为0．2～0．3mg／L,回流比为10时,TN和NH—LN平均去除率分别达到81％和85％,平均出水浓度低至13．2mg／L和7．7mg／L。     

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。     

好氧颗粒污泥技术用于味精废水处理的研究

以厌氧颗粒污泥为接种污泥,采用人工模拟废水在SBR反应器内培养好氧颗粒污泥,35 d后颗粒污泥成熟,反应器对COD和NH4+-N的去除率分别高于95%和99%。采用该反应器处理味精废水,当COD、NH4+-N的容积负荷分别为2.4、0.24 kg/(m3.d)时,对COD、NH4+-N和TN的去除率分别在90%、99%和85%左右,且颗粒污泥未出现解体的现象。以厌氧颗粒污泥为接种污泥、味精废水为进水,在与上述相同条件下培养好氧颗粒污泥,经过60 d的培养,反应器内的污泥以絮状污泥为主,该系统对COD、NH4+-N和TN的去除率分别为85%、99%和70%。     

以农田灌溉为目的的酒糟污水厌氧——脱硫处理新工艺

以试验为根据报导了采用高负荷上流式厌氧污泥床(UASB)反应器对酒糟污水进行中温(35℃)厌氧处理,厌氧出水进行空气氧化脱硫,最终出水用于农田灌溉的酒糟污水处理新工艺。试验还对UASB反应器中颗粒污泥的培养和高于中温时温度对UASB反应器工艺性能的影响作了较系统的研究。     

基于好氧颗粒污泥的三槽交替反应器的运行效能与微生物菌群分析

在新开发的三槽交替反应器基础上接种厌氧反应器中的颗粒污泥,采用较高的进水负荷快速培养好氧颗粒污泥,考察了三槽交替反应器的运行效能,并进行微生物菌群结构分析.结果表明:在PLC自动控制条件下,反应器实现了周期性独立控制.经过32 d的培养,好氧颗粒污泥在厌氧颗粒污泥的基础上培养成功.在人工配水的条件下,氮、磷去除效能较低...     

SBR好氧颗粒污泥的理化性质研究

以厌氧颗粒污泥为接种污泥,以葡萄糖为碳源,采用SBR反应器培养出了好氧颗粒污泥,对其外观、理化性质及除污效果进行了考察。结果表明,好氧颗粒污泥呈黄色或黄褐色,外观呈球状或椭球状,其表面和内部存在孔隙。好氧颗粒污泥的湿密度平均为1.057 g/cm^3,高于普通活性污泥的;含水率为96.7%～98.4%,低于普通活性污泥的;完整系数（IC）为97%～100%,具有较好的物理强度。好氧颗粒污泥的平均粒径为1.3 mm,小于厌氧颗粒污泥的;MLVSS/MLSS值为0.78～0.91,具有良好的生物活性;SVI值〈70 mL/g,沉降速度为12～78 m/h,具有良好的沉降性能。反应器稳定运行初期,对COD的去除率〉80%,对NH3-N的去除率为54.8%～75.7%,表明好氧颗粒污泥具有良好的除污效果。     

颗粒活性炭加速厌氧反应器污泥颗粒化的研究

为克服厌氧反应器启动慢和启动难的问题,以UASB反应器为代表,向反应器内投加颗粒活性炭以加快厌氧污泥颗粒化进程,并采用扫描电子显微镜观察颗粒污泥的生长情况.结果表明,在试验的第64天即完成了厌氧污泥颗粒化的全部过程,培养出的颗粒污泥具有厌氧颗粒污泥的基本特征和典型的生化特性,并对啤酒废水有很好的处理效果.可见,投加颗粒活性炭可加速厌氧污泥颗粒化进程,并能有效维持厌氧反应器的稳定运行.     

MBR中磁种好氧颗粒污泥的培养及对膜污染的影响

以人工合成模拟废水为处理对象,在膜生物反应器(MBR)中培养磁种好氧颗粒污泥,并考察了其对膜污染的影响。结果表明,由絮状活性污泥培养磁种好氧颗粒污泥,开始污泥中大量繁殖丝状菌,然后丝状菌缠绕成细小的颗粒,最后慢慢形成颗粒污泥,其外表光滑,近似呈圆球形或椭球状。培养成熟的磁种好氧颗粒污泥的粒径为0.47~4.1 mm,平均为1.7 mm;SVI70mL/g,远低于普通活性污泥的(100~150 mL/g);沉降速度随粒径的增加而增大,范围为30~91m/h,而普通活性污泥的只有8~10 m/h。同时,比较了絮状污泥MBR和磁种好氧颗粒污泥MBR在运行过程中膜通量的变化趋势,结果表明:磁种好氧颗粒污泥MBR的膜通量下降速度低于普通絮状活性污泥MBR的,这是磁种好氧颗粒污泥和反应器的流态共同作用的结果。     

A/O SBR中同步硝化反硝化除磷颗粒污泥的富集

以聚糖菌颗粒污泥为接种污泥，在厌氧／好氧SBR中成功富集了具有同步硝化反硝化除磷效果的颗粒污泥。结果表明，培养过程中，污泥总磷含量、厌氧释磷量及磷酸盐去除率的提高表明反应器中聚磷菌逐渐替代聚糖菌成为优势菌种；培养末期颗粒污泥的粒径为600～1000μm，SVI为48mL／g，有机物主要在厌氧阶段被去除并以胞内聚合物（PHB）的形式储存，厌氧阶段对TOC的去除率为87％，对TOC的总去除率为90％，对磷酸盐的去除率为95．6％；氮的去除是在好氧条件下经同步硝化反硝化完成的，且PHB为主要的反硝化碳源，对氨氮的去除率为99．3％，对总氮的去除率为85．5％。     

好氧SBR反应器中污泥颗粒化过程的成核研究

采用人工配制的模拟生活污水,以好氧絮状污泥为接种污泥,通过调控运行条件,在低高径比、纯好氧曝气的序批式反应器(SBR)中成功培养出了高活性的好氧颗粒污泥晶核,并对其性能、除污效果和成核影响因素进行了研究.结果表明:成熟好氧颗粒污泥晶核平均粒径为0.5mm,沉降性能较好,SVI为77mL/g;成熟好氧颗粒污泥晶核对COD和NH3-N都有较高的去除率,分别达到了90%和97%;水力剪切力是影响污泥成核的关键因素.     

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％。     

SBR系统同步脱氮除磷好氧颗粒污泥的培养

以普通絮状活性污泥为种泥,采用人工配制的模拟生活污水,在序批式反应器(SBR)中成功地培养出了具有同步脱氮除磷功能的好氧颗粒污泥.研究表明,通过提高COD负荷和逐步减少污泥沉降时间以造成选择压,可促进颗粒污泥的形成.成熟的颗粒污泥形态完整、结构致密、表面光滑、外观呈橙黄色,为近似球形或椭球形,粒径大多在0.5～1.0 mm之间,污泥体积指数为27.0 mL/g,MLSS为6 800 mg/L.该颗粒污泥对NH4 -N的去除率接近100%,对COD和PO3-4-P的平均去除率均在80%以上,而且颗粒污泥中的微生物种群具有多样性,所形成的微生态系统更稳定,抗外界干扰及自身恢复调节能力较强.     

2-fluorophenol degradation by aerobic granular sludge in a sequencing batch reactor

Aerobic granular sludge is extremely promising for the treatment of effluents containing toxic compounds, and it can economically compete with conventional activated sludge systems. A laboratory scale granular sequencing batch reactor (SBR) was established and operated during 444 days for the treatment of an aqueous stream containing a toxic compound, 2-fluorophenol (2-FP), in successive phases. Initially during ca. 3 months, the SBR was intermittently fed with 0.22 mM of 2-FP added to an acetate containing medium. No biodegradation of the target compound was observed. Bioaugmentation with a specialized bacterial strain able to degrade 2-FP was subsequently performed. The reactor was thereafter continuously fed with 0.22 and 0.44 mM of 2-FP and with 5.9 mM of acetate (used as co-substrate), for 15 months. Full degradation of the compound was reached with a stoichiometric fluoride release. The 2-FP degrading strain was successfully retained by aerobic granules, as shown through the recovering of the strain from the granular sludge at the end of the experiment. Overall, the granular SBR has shown to be robust, exhibiting a high performance after bioaugmentation with the 2-FP degrading strain. This study corroborates the fact that bioaugmentation is often needed in cases where biodegradation of highly recalcitrant compounds is targeted.     

Alternating anoxic feast/aerobic famine condition for improving granular sludge formation in sequencing batch airlift reactor at reduced aeration rate

In this study the influence of a pre-anoxic feast period on granular sludge formation in a sequencing batch airlift reactor is evaluated. Whereas a purely aerobic SBR was operated as a reference (reactor R2), another reactor (R1) was run with a reduced aeration rate and an alternating anoxic-aerobic cycle reinforced by nitrate feeding. The presence of pre-anoxic phase clearly improved the densification of aggregates and allowed granular sludge formation at reduced air flow rate (superficial air velocity (SAV) = 0.63 cm s⁻¹). A low sludge volume index (SVI₃₀ = 45 mL g⁻¹) and a high MLSS concentration (9–10 g L⁻¹) were obtained in the anoxic/aerobic system compared to more conventional results for the aerobic reactor. A granular sludge was observed in the anoxic/aerobic system whilst only flocs were observed in the aerobic reference even when operated at a high aeration rate (SAV = 2.83 cm s⁻¹). Nitrification was maintained efficiently in the anoxic/aerobic system even when organic loading rate (OLR) was increased up to 2.8 kg COD m⁻³ d⁻¹. In the contrary nitrification was unstable in the aerobic system and dropped at high OLR due to competition between autotrophic and heterotrophic growth. The presence of a pre-anoxic period positively affected granulation process via different mechanisms: enhancing heterotrophic growth/storage deeper in the internal anoxic layer of granule, reducing the competition between autotrophic and heterotrophic growth. These processes help to develop dense granular sludge at a moderate aeration rate. This tends to confirm that oxygen transfer is the most limiting factor for granulation at reduced aeration. Hence the use of an alternative electron acceptor (nitrate or nitrite) should be encouraged during feast period for reducing energy demand of the granular sludge process.     

Biomass characteristics in three sequencing batch reactors treating a wastewater containing synthetic organic chemicals

The physical and biochemical characteristics of the biomass in three lab-scale sequencing batch reactors (SBR) treating a synthetic wastewater at a 20-day target solids retention time (SRT) were investigated. The synthetic wastewater feed contained biogenic compounds and 22 organic priming compounds, chosen to represent a wide variety of chemical structures with different N, P and S functional groups. At a two-day hydraulic retention time (HRT), the oxidation-reduction potential (ORP) cycled between -100 (anoxic) and 100 mV (aerobic) in the anoxic/aerobic SBR, while it remained in a range of 126+/-18 and 249+/-18 mV in the aerobic sequencing batch biofilm reactor (SBBR) and the aerobic SBR reactor, respectively. A granular activated sludge with excellent settleability (SVI=98+/-31 L mg(-1)) developed only in the anoxic/aerobic SBR, compared to a bulky sludge with poor settling characteristics in the aerobic SBR and SBBR. While all reactors had very good COD removal (>90%) and displayed nitrification, substantial nitrogen removal (74%) was only achieved in the anoxic/aerobic SBR. During the entire operational period, benzoate, theophylline and 4-chlorophenol were completely removed in all reactors. In contrast, effluent 3-nitrobenzoate was recorded when its influent concentration was increased to 5 mg L(-1) and dropped only to below 1 mg L(-1) after 300 days of operation. The competent (active) biomass fractions for these compounds were between 0.04% and 5.52% of the total biomass inferred from substrate-specific microbial enumerations. The measured competent biomass fractions for 4-chlorophenol and 3-nitrobenzoate degradation were significantly lower than the influent COD fractions of these compounds. Correspondent to the highest competent biomass fraction for benzoate degradation among the test SOCs, benzoate oxidation could be quantified with an extant respirometric technique, with the highest specific oxygen uptake rate (SOUR(benzoate), 0.026 g O2 h(-1) g(-1) XCOD) in the anoxic/aerobic SBR. These combined results suggest that operating SBRs with alternative anoxic/aerobic cycles might facilitate the formation of granular sludge with good settleability, and retain comparable removal of nitrogen and synthetic organic compounds. Hence, the practice of anoxic/aerobic cycling should be considered in wastewater treatment systems whenever possible.     

Development of a 2-sludge, 3-stage system for nitrogen and phosphorous removal from nutrient-rich wastewater using granular sludge and biofilms

A novel 2-sludge 3-stage process using a combination of granular sludge and biofilm was developed to achieve biological removal of nitrogen and phosphorus from nutrient-rich wastewater. The system consists of a granular sequencing batch reactor (SBR) working under alternating anaerobic/anoxic conditions supplemented with a short aerobic phase and an aerobic biofilm SBR. The wastewater is first fed to the granular SBR reactor, where easily biodegradable carbon sources are taken up primarily by polyphosphate accumulating organisms (PAOs). The supernatant resulting from quick settling of the granular sludge is then fed to the biofilm SBR for nitrification, which produces oxidized nitrogen that is returned to the granular reactor for simultaneous denitrification and phosphorus removal. While maximizing the utilization of organic substrates and reducing operational costs, as do other 2-sludge processes previously reported in literature, the proposed system solves the bottleneck problem of traditional 2-sludge systems, namely high effluent ammonia concentration, due to its high-volume exchange ratios. An ammonia oxidation rate of 32 mg N/Lh was achieved in the biofilm SBR, which produced nitrite as the final product. This nitrite stream was found to cause major inhibition on the anoxic P uptake and also to result in the accumulation of N(2)O. These problems were solved by feeding the nitrite-containing stream continuously to the granular reactor in the anoxic phase. With a nitrogen and phosphorus removal efficiency of 81% and 94%, respectively, the system produces an effluent that is suitable for land irrigation from a wastewater stream containing 270 mg N/L of total nitrogen and 40 mg P/L of total phosphorus.     

Development of granular sludge for textile wastewater treatment

Microbial granular sludge that is capable to treat textile wastewater in a single reactor under intermittent anaerobic and aerobic conditions was developed in this study. The granules were cultivated using mixed sewage and textile mill sludge in combination with anaerobic granules collected from an anaerobic sludge blanket reactor as seed. The granules were developed in a single sequential batch reactor (SBR) system under alternating anaerobic and aerobic condition fed with synthetic textile wastewater. The characteristics of the microbial granular sludge were monitored throughout the study period. During this period, the average size of the granules increased from 0.02 ± 0.01 mm to 2.3 ± 1.0 mm and the average settling velocity increased from 9.9 ± 0.7 m h⁻¹ to 80 ± 8 m h⁻¹. This resulted in an increased biomass concentration (from 2.9 ± 0.8 g L⁻¹ to 7.3 ± 0.9 g L⁻¹) and mean cell residence time (from 1.4 days to 8.3 days). The strength of the granules, expressed as the integrity coefficient also improved. The sequential batch reactor system demonstrated good removal of COD and ammonia of 94% and 95%, respectively, at the end of the study. However, only 62% of color removal was observed. The findings of this study show that granular sludge could be developed in a single reactor with an intermittent anaerobic-aerobic reaction phase and is capable in treating the textile wastewater.