Sequencing batch reactor system for nutrient removal: ORP and pH Profiles

The sequencing batch reactor (SBR) process is known for its flexibility to meet a wide range of treatment needs, including nutrient removal. However, information related to the operational stability of SBR nutrient removal systems and control parameters to adjust the cyclic duration is sparse. Consequently, this study was undertaken to identify process parameters (pH and oxidation reduction potential) that could be useful for monitoring and real-time control purposes. In general, the system achieved removal efficiencies of 91, 98 and 98%, respectively, for Chemical Oxygen Demand, total nitrogen and phosphate at the solids retention time of 10 days, with a cyclic duration of 6 h. Shock loadings of nitrogen (20 mg dm⁻³ of NH−N, four cycles) exhibited little impact on effluent quality, except for a higher nitrate content. Activated sludge settled well throughout the entire study period. Several significant points associated with different reactions within SBR cycle, e.g. end of nitrification, end of phosphate release and completion of phosphate uptake, were identified in pH profiles. Slope changes in pH profiles (dpH/dt, or d²pH/dt²) were found to better represent the corresponding biological reactions. The application of these significant points in pH profiles as real time control parameters appears promising.     

序批式反应器中反硝化除磷脱氮的研究

为了提高污水脱氮除磷的效率,研究采用序批式反应器(SBR工艺)厌氧、好氧和缺氧(AOA)的运行方式富集反硝化聚磷菌(DPB),实现同步脱氮除磷。结果表明:在好氧段投加甲醇作为碳源(25—40 mg/L)可有效抑制好氧吸磷,对硝化反应影响较小,能够在缺氧段实现同时反硝化脱氮除磷。SBR反应器稳定运行10个月,当进水NH4+-N、PO43--P分别为30,15 mg/L时,总氮(TN)和PO43--P的平均去除率分别为82.5%和92.1%。聚磷菌能够利用硝酸盐作为电子受体,DPB占总聚磷菌的比例达到44.8%。与A2O运行方式相比,AOA运行方式更有利于实现DPB的富集。     

Simultaneous removal of carbon,nitrogen and phosphorus from wastewater by coupling two-step anaerobic digestion with a sequencing batch reactor

The objective of this study was to develop an integrated process for simultaneous removal of carbon, nitrogen and phosphorus from industrial wastewaters. The process consisted of a-two step anaerobic digestion reactor, for carbon removal, coupled with a sequencing batch reactor (SBR) for nutrient removal. In the proposed process, carbon is eliminated into biogas by anaerobic digestion: acidogenesis and methanogenesis. The volatile fatty acids (VFA) produced during the first step of anaerobic digestion can be used as electron donors for both dephosphatation and denitrification. In the third reactor (SBR) dephosphatation and nitrification are induced through the application of an anaerobic–aerobic cycle. This paper describes the first trials and experiments on the SBR and a period of 210 days during which the SBR was connected to the acidogenic and methanogenic reactors. It was shown that nitrification of ammonia took place in the SBR reactor, during the aerobic phase. Furthermore, denitrification and VFA production were achieved together in the acidogenic reactor, when the efflux of nitrates from the SBR reactor was added to the first reactor influx. The proposed process was fed with a synthetic industrial wastewater, the composition of which was: total organic carbon (TOC)=2200 mg dm⁻³, total Kjeldahl nitrogen (TKN)=86 mg dm⁻³, phosphorus under phosphate form (P-PO₄)=20 mg dm⁻³. In these conditions, removals of carbon, nitrogen and phosphorus were 98%, 78% and 95% respectively. The results show that the combination of the two-step anaerobic digestion reactor and an SBR reactor is effective for simultaneous carbon, nitrogen and phosphorus removal. Reactor arrangements enabled zones of bacterial populations to exist. Complete denitrification occurred in the acidogenic reactor and hence the anaerobic activity was not reduced or inhibited by the presence of nitrate, thus allowing high TOC removal. Stable phosphorus release and phosphorus uptake took place in the SBR after coupling of the three reactors. A fast-settling compact sludge was generated in the SBR with the operational conditions applied, thus giving good separation of supernatant fluid. The benefits from this process are the saving of (i) an external carbon source for denitrification and phosphorus removal, (ii) a reactor for the denitrification step. © 1998 Society of Chemical Industry     

厌氧序批式反应器的特征与应用

厌氧序批式反应器(ASBR)作为一种新型的高效厌氧反应器具有污泥持留量高、水力停留时间短、处理效率高等优点,可以单独或与其他工艺相结合有效的处理食品加工废水、家畜饲养废水、屠宰场废水等高浓度有机废水．还可以应用于处理城市污水和低浓度工业废水。介绍ASBR的工艺特点,国内外研究概况,并对ASBR的应用现状和发展前景进行了分析．认为ASBR反应器在我国的废水处理中有良好的应用前景。     

Hydrogen production from sucrose using an anaerobic sequencing batch reactor process

Studies on hydrogen production in an anaerobic sequencing batch reactor (AnSBR) indicated that the anaerobic acidogenic conversion of sucrose could produce hydrogen. The hydrogen production of acclimated sewage sludge depended on hydraulic retention time (HRT) and reaction period/settling period (R/S) ratio. A short equivalent HRT, even up to 4 h, gave good hydrogen productivity and high hydrogen production rate (HPR) values. For each equivalent HRT, R/S ratio control also increased the hydrogen productivity and HPR. Reactor operation at an intimate control of HRT and R/S ratio was preferable for hydrogen production. At HRT 8 h, R/S ratio 5.6 and an organic loading rate of 0.23 mol‐sucrose dm^?3 day^?1, each mole of sucrose in the mesophilic hydrogenic reactor yielded 2.6 mole of hydrogen; each gram of biomass produced 0.069 mole of hydrogen per day. Copyright © 2003 Society of Chemical Industry     

厌氧序批式反应器的厌氧氨氧化工艺启动运行

在厌氧序批式反应器中接种好氧硝化污泥,进行了培养厌氧氨氧化污泥的研究。在进水pH值为7.2～7.8,温度为30±1℃的条件下运行142d,成功培养出厌氧氨氧化污泥。反应器内的污泥量(以VSS计)由原来的9.90g/L增加到18.99g/L,水力停留时间为1.20d,总氮容积负荷为0.4318kg/(m·3d)时,总氮去除率最高达到93.3%,平均为80.5%,氨氮和亚硝酸盐氮的去除率最高分别达到93.9%和99.8%,平均去除率分别为81.2%和85.7%,氨氮和亚硝酸盐氮去除的比例为1∶1.387±0.024。对该工艺优化实验研究表明,适宜pH值为7.2～7.8,最适宜温度为35℃;且适度强化反硝化作用有利于提高反应器的脱氮性能。     

Simultaneous removal of nitrogen and phosphorus from swine wastewater in a sequencing batch biofilm reactor

In this study, the performance of a sequencing batch biofilm reactor (SBBR) for removal of nitrogen and phosphorus from swine wastewater was evaluated. The replacement rate of wastewater was set at 12.5%throughout the exper-iment. The anaerobic and aerobic times were 3 h and 7 h, respectively, and the dissolved oxygen concentration of the aerobic phase was about 3.95 mg·L?1. The SBBR process demonstrated good performance in treating swine wastewater. The percentage removal of total chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), total nitrogen (TN), and total phosphorus (TP) was 98.2%, 95.7%, 95.6%, and 96.2%at effluent concentrations of COD 85.6 mg·L?1, NH4+-N 35.22 mg·L?1, TN 44.64 mg·L?1, and TP 1.13 mg·L?1, respectively. Simultaneous nitrification and denitrification phenomenon was observed. Further improvement in removal efficiency of NH4+-N and TN occurred at COD/TN ratio of 11:1, with effluent concentrations at NH4+-N 18.5 mg·L?1 and TN 34 mg·L?1, while no such improvement in COD and TP removal was found. Microbial electron microscopy analysis showed that the fil er surface was covered with a thick biofilm, forming an anaerobic–aerobic microenvironment and facilitating the removal of nitrogen, phosphorus and organic matters. A long-term experiment (15 weeks) showed that stable removal efficiency for N and P could be achieved in the SBBR system.     

厌氧序批式反应器快速形成颗粒污泥技术研究

厌氧序批式反应器(ASBR)初次启动用厌氧消化污泥接种,比较了投加聚季铵盐(A柱)与空白对照(B柱)2个反应器的颗粒污泥形成过程。启动后以每隔2 d投加1次的投加方式向反应器中不断补充聚季铵盐,聚季铵盐投加质量与污泥质量之比取1.6 mg/g。结果表明,A柱颗粒污泥平均粒径达到0.72 mm仅需73 d,比B柱提前了25 d。A柱在启动56 d后COD负荷达到10 g/(L.d),形成的颗粒污泥平均粒径大于B柱(0.55 mm),产甲烷活性也较高。所以投加聚季铵盐能有效促进污泥颗粒化进程。     

污泥固体停留时间对实时控制生物脱氮SBR中亚硝酸盐积累的影响

In this study,four sequencing batch reactors(SBR),with the sludge retention time(SRT)of 5,10,20 and 40 d,were used to treat domestic wastewater,and the effect of SRT on nitrite accumulation in the biological nitrogen removal SBR was investigated.The real-time control strategy based on online parameters,such as pH,dissolved oxygen(DO)and oxidation reduction potential(ORP),was used to regulate the nitrite accumulation in SBR. The model-based simulation and experimental results showed that with the increase of SRT,longer time was needed to achieve high level of nitritation.In addition,the nitrite accumulation rate(NAR)was higher when the SRT was relatively shorter during a 112-day operation.When the SRT was 5 d,the system was unstable with the mixed liquor suspended solids(MLSS)decreased day after day.When the SRT was 40 d,the nitrification process was significantly inhibited.SRT of 10 to 20 d was more suitable in this study.The real-time control strategy combined with SRT control in SBR is an effective method for biological nitrogen removal via nitrite from wastewater.     

SBR工艺研究进展

近年来，间歇式活性污泥法由于其工艺简单、运行灵活、基建和运行费用低，已成为国内外竞相研究和开发的热门污水生物处理工艺。在阐述了SBR反应器的工艺特点及计算的基础上，对近年来其主要的变形丁艺(ICEAS，CAST，IDEA，DAT—IAT，UNITANK等)和其他新型SBR工艺的发展进行了综述。同时指出随着对该工艺的研究和开发，它必将成为一种很有竞争力的污水处理工艺，拥有良好的发展前景。     

碳源在连续批式反应器中对生物养分移动的影响

连续批式操作用来研究利用不同的碳源从合成废水中移动养分(COD、 NH4-N、 NO3-N、 PO4-P)的过程,本操作包括缺氧症、缺氧的、有氧的、缺氧和有氧的(An、Ax、Ox、Ax、Ox)时期,分别持续2 h、1 h、4.5 h、1.5 h、1.5 h.葡萄糖、醋酸盐、葡萄糖和醋酸盐混合物作为碳源在机械中产生的COD∶N∶P为100∶5∶1.5,污泥稳定保存10 d.当葡萄糖和醋酸盐混合物比例是50∶50时,COD、NH4-N、NO3-N和PO4-P最大迁移率分别是96%、87%、81%和90%.     

The beneficial role of intermediate clarification in a novel MBR based process for biological nitrogen and phosphorus removal

BACKGROUND: A novel membrane bioreactor (MBR) is described, employing an intermediate clarifier. Unlike the established function of a final clarifier in a conventional biological nutrient removal system, the role of an intermediate clarifier has rarely been studied. Thus, this work focused on explaining the fate of nutrients in the intermediate clarifier, as influenced by the hydraulic retention time (HRT) of the preceding anaerobic bioreactor. RESULTS: The system was tested with two different anaerobic/anoxic/aerobic biomass fractions of 0.25/0.25/0.5 (run 1) and 0.15/0.35/0.45 (run 2) using synthetic wastewater. The major findings of the study were that phosphorus (P) removal was affected by the role of the intermediate clarifier. In run 1, P was removed at a rate 0.16 g d⁻¹ in the intermediate clarifier while in run 2, additional P was released at 0.49 g d⁻¹. The nitrogen (N) removal efficiencies were 74 and 75% for runs 1 and 2 respectively, while P removal was 91 and 96%. P uptake by denitrifying phosphate accumulating organisms (DPAOs) accounted for 41–52% of the total uptake in the MBR. CONCLUSIONS: This study found that the intermediate clarifier assisted chemical oxygen demand (COD), N, and P removal. With respect to the fate of P, the intermediate clarifier functioned as an extended anaerobic zone when the HRT of the preceding anaerobic zone was insufficient for P release, and as a pre‐anoxic zone when the anaerobic HRT was adequate for P release. Copyright © 2008 Society of Chemical Industry     

序批式膜生物反应器处理生活污水的特性

研究了中试规模序批式膜生物反应器处理生活污水的特性.发现其对COD_Cr、NH₃-N及TN的去除效果可分别达到95.0%、96.3%及38.0%;过膜阻力增加率为1.032 kPa•m^-1.TN去除率偏低的主要原因在于缺少搅拌装置,在静置阶段时,污泥大部分沉积在反应器底部（系统运行期间30 min沉降比均低于40%）,从而使反硝化细菌不能充分与水溶液中的NO_x-N接触.采用空间排阻液相色谱法对混合液及膜污染物进行分子量分布测定,发现大量大分子物质在反应器内、膜面及膜孔内积累,相对分子质量大于10⁴的有机物分别占64.0%、38.0%.经过物理及化学清洗,膜通量恢复了73.4%,多糖含量为清洗前的30.4%,说明多糖是造成不可逆污染的主要物质.     

厌氧序批式反应器快速启动的影响因素述评

厌氧序批式反应器是第三代新型高速厌氧反应器,其快速启动运行规律的研究相对较少。总结了目前国内外关于ASBR快速启动的研究进展情况,并结合试验成果,论述了ASBR快速启动的影响因素,包括运行方式、搅拌、种泥类型、投加物、反应器构型等方面,以及当前研究中存在的问题。     

进水碱度对厌氧序批式活性污泥法工艺的影响

厌氧序批式活性污泥法（ASBR）试验装置有效容积6 L,间歇运行,用葡萄糖人工合成废水为底物,进水COD₀浓度6700 mg·L^-1,进水中逐步减少碱度（Alk）投加量。考察了COD₀/Alk分别为1.0∶1、2.0∶1、2.5∶1、3.4∶1、4.2∶1和4.8∶1等6种碱度条件下的挥发性脂肪酸（VFA）、碳酸氢盐碱度（BAlk）、CO₂分压和pH的变化规律,以确定偏酸性条件下ASBR工艺的运行效果和稳定性。结果表明,进水碱度对VFA、BAlk、CO₂分压和pH均有影响,对反应初期的产酸速率的影响尤其突出。COD₀/Alk=1.0∶1时,消化液pH基本保持在7.20以上;COD₀/Alk=3.4∶1时,反应初期产酸速率增加,出现了pH＜6.5的时段,消化过程已经向偏酸性发酵状态发展;COD₀/Alk≥4.2∶1之后,反应期内大部分时段的pH低于6.5,最低pH为6.10,偏酸性程度增大,但进行的仍是典型的以CH₄为最终产物的厌氧消化过程。所有碱度条件下的COD去除率均≥97%,证明了ASBR工艺在低pH、低碱度下实现产甲烷过程的可行性。     

活性污泥强化生物除磷体系的进展研究

强化生物除磷在全世界诸多污水处理厂中已经得到广泛应用,在城镇污水排入水体环境之前,含高浓度磷的废水必须经过强化除磷处理。生物除磷方法比化学方法更加环保,经济,现在已经得到很大的认可和推广。这篇综述主要是对生物除磷的研究进展做比较系统的总结,并对生物除磷方法在实际污水处理中的应用的优势和难度做出评价,为将来相关问题的研究提供系统的依据。     

ASBR反应器稳态建立的研究

应用厌氧序批间歇式反应器(ASBR),以葡萄糖为唯一碳源,在中温(35℃)条件下对反应器进行启动,并建立稳态。实验表明,经过172 d的运行,ASBR反应器的容积负荷为5 kg COD/m3.d,COD的去除率在92%以上,出水的VFA稳定在250 mg/L左右,每周期的累积产气量为4.8 L左右,污泥的甲酸、乙酸、丙酸和丁酸活性分别为:0.334 8,1.258 0,1.094和0.746 40 g COD-CH4/g VSS.d。