污泥回流比对A_2N反硝化除磷工艺脱氮除磷的影响

以城市生活污水为研究对象,探讨了不同的超越污泥和回流污泥回流比对A2N工艺脱氮除磷的影响.在超越污泥回流比与回流污泥回流比相同且分别为0.3、0.4和0.6的条件下,A2N工艺对COD的平均去除率分别为92.5%、90.3%、91.6%,相应的出水COD为20.3、28.4、25.3 mg/L;对总氮的平均去除率分别为87.1%、90%、84.9%,出水总氮分别为6.75、5.43、6.95mg/L;对磷的平均去除率分别为99.5%、99.6%和99.0%,出水磷浓度分别为0.02、0.02、0.05mg/L.当回流比为0.4时,A2N系统的除污效果最好.研究还发现,超越污泥流量直接决定了未经硝化而直接进入缺氧池的氨氮量,进而影响出水氨氮浓度.因此,在保证缺氧池有足够污泥的前提下,应尽可能减小超越污泥流量,以降低出水氨氮浓度.     

Treatment in municipal plants: Innovations for removal of phosphorus

The paper provides a background of a variety of different phosphorus removal techniques which have been reported in the literature. Forty-nine different references which may be described under the general headings of “biological”, “chemical”, “chemical-biological”, and “chemical-physical”, have been abstracted and described under a series of salient headings. The manner in which they are described considers the point of application of the process, the percentage removal of phosphorus which was experienced, the cost of the process where this was given, and whether or not the process is related to a concentrated sub-stream within the waste water treatment plant.The main emphasis of the paper deals with the concept of removing phosphorus from waste water by using a sub-stream within the plant which naturally has phosphorus concentrated considerably above the ambient (influent) concentration.A continuous laboratory-scale plant was studied, operating under contact stabilization conditions, and using an anaerobic holding technique on the return activated sludge, phosphorus was removed from the supernatant of the return sludge stream. The plant was operated with and without the anaerobic holding modification, and the results of the operation are reported in the paper. Both before and after the modification, the organic carbon as measured by COD removal was of the order of 90 per cent; and after modification of the plant to release the phosphorus from the return sludge stream, phosphorus removals jumped from 10 to 30 per cent up to a high of 75 to 90 per cent removal. A very slight decrease in sludge activity could be observed due to the anaerobic holding, but the very slight reduction in COD removal was more than offset by the increased removal of soluble phosphorus through the supernatant of the return sludge line.Development of this process onto a full-scale basis is considered as the next stage of this research programme.     

多点交替进水五箱一体式工艺污泥回流比研究

介绍了多点交替进水五箱一体式工艺的流程与特点，研究了不同污泥回流比下反应器对氮、磷的去除效果。结果表明，在运行周期为16h、污泥回流比为55％的条件下，反应器对COD、BOD5、NH4^＋-N、TN、TP的去除率分别达到78％、84％、86％、70％、89％。此外，建立了反应池内污泥浓度的分布模型，并计算得出不同回流比下污泥浓度的变化规律，通过对计算值与试验检测结果的比较，提出了后期工艺的改进方向。     

Development of an innovative vertical submerged membrane bioreactor (VSMBR) for simultaneous removal of organic matter and nutrients

A novel vertical submerged membrane bioreactor (VSMBR) composed of anoxic and oxic zones in one reactor was developed in an attempt to reduce the problems concerning effective removal of pollutants from synthetic wastewater including glucose as a sole carbon source as well as membrane fouling. The optimal volume ratio of anoxic zone/oxic zone was found as 0.6. The desirable internal recycle rate and hydraulic retention time (HRT) for effective nutrient removal were 400% and 8h, respectively. Under these conditions, the average removal efficiencies of total nitrogen (T-N) and total phosphorus (T-P) were 75% and 71%, respectively, at the total chemical oxygen demand (T-COD)/T-N ratio of 10. In addition, the VSMBR showed high specific removal rates of nitrogen and phosphorus while the biomass growth yield from the reactor was about 20% of the conventional activated sludge process.     

(AO)2-SBBR反硝化除磷工艺处理低碳城市污水

低碳源浓度城市污水的脱氮除磷一直是个难题，为此在AO-SBBR工艺中引入一个缺氧段而形成（AO）2-SBBR工艺，研究了AO-SBBR和（AO）2-SBBR对低碳源浓度城市污水中氮、磷的去除效果。试验结果表明：在进水BOD5／TN=3、BOD5／TP=17的情况下，（AO）2-SB．BR工艺比AO-SBBR工艺具有更好的同步脱氮除磷效果，对总磷的去除率达到了79．8％，对总氮的去除率从25．83％提高到51．26％，出水水质达到了《城镇污水处理厂污染物排放标准》的一级标准。该工艺有效解决了低碳源浓度城市污水在同步脱氮除磷过程中有机物不足的问题，并在单一反应器中实现了反硝化除磷菌的增殖过程，反硝化除磷菌占聚磷菌的比例从14．82％增长到63．04％；反硝化除磷菌能够以低浓度的亚硝酸盐氮作为电子受体进行缺氧吸磷，如亚硝酸盐氮〉10mg／L则会抑制反硝化除磷菌的活性，而且这种抑制作用并不是瞬时的，至少要持续一段时间其活性才能恢复。     

改良型Carrousel氧化沟的运行与改造

改良型Carrousel氧化沟在实际运行过程中存在污泥沉积严重、脱氮除磷效果不佳、污泥回流比的控制不够灵活等问题，采用扩容选择池、氧化沟内增加潜水推流器、安装回流污泥计量装置等方式进行技术改造，彻底解决了积泥问题，提高了脱氮除磷效率，并节省了大量能源，降低了生产成本，使系统实现良好的运行状态。     

剩余污泥生态稳定化研究

利用中试规模的人工湿地对污泥进行了为期4 a的生态稳定化处理。系统占地80 m 2,填料层厚度为0.6 m,超高0.5 m,湿地植物选用芦苇。系统前2 a为污泥负荷期,后2 a自然稳定期。进泥TS、VS、含水率分别为平均22.34 g/L、7.76 g/L和97%,污泥负荷平均0.691 kg(TS）/m 2·d。在第1 a的系统调整期内,渗滤液COD去除率在60%～80%;而第2 aCOD去除率低于第1 a,为40％～50%;出水COD在100～200 mg/L之间。在负荷期内,随着运行时间的延长,也即随着污泥积存厚度的增加,渗滤液透过积泥层的时间变化不定,即渗滤液并非均匀下渗,而是部分渗滤液优先沿阻力最小的植物茎壁、根系以及积存污泥中大的孔隙向下流动。在第3 a和第4 a的自然稳定期内,污泥脱水较为充分,含水率分别降至平均34.3%和30.5%;污泥有机质含量分别降至平均16.8%和10.24%;稳定化污泥的全氮和全磷含量分别为平均0.98%和0.27%。对比发现,系统内植物量和植物营养成分都比野生植物高。     

Aerobic moving bed biofilm reactor treating thermomechanical pulping whitewater under thermophilic conditions

The continuously operated laboratory scale Kaldnes moving bed biofilm reactor (MBBR) was used for thermophilic (55 degrees C) aerobic treatment of TMP whitewater. In the MBBR, the biomass is grown on carrier elements that move along with the water in the reactor. Inoculation with mesophilic activated sludge gave 60-65% SCOD removal from the first day onwards. During the 107 days of experiment, the 60-65% SCOD removals were achieved at organic loading rates of 2.5-3.5 kg SCODm(-3) d(-1), the highest loading rates applied during the run and HRT of 13-22h. Carbohydrates, which contributed to 50-60% of the influent SCOD. were removed by 90-95%, while less than 15% of the lignin-like material (30-35% of SCODin) was removed. The sludge yield was 0.23g VSSg SCOD(-1)removed. The results show that the aerobic biofilm process can be successfully operated under thermophilic conditions.     

序批式复合反应器强化同步脱氮除磷

利用序批式复合反应器(SBHR)中同时存在的活性污泥和悬浮生物膜混合生物体系,进行了强化脱氮除磷的试验研究。连续稳定运行3个月后,系统对TN、TP和COD的平均去除率分别达到90%、95%和95%,处理效果稳定。该系统的悬浮生物膜与活性污泥的混合体系中生物种群具有多样化特征,所形成的微生物生态系统较稳定,抗外界干扰及恢复调节能力强;悬浮微生物体系能与水体形成复杂的整体螺旋上升、局部紊流的流态,有利于在空间形成有机污染物浓度梯度分布,使氧气和硝酸盐氮等电子受体和有机底物的传质效果良好。     

The effect of water hardness on nitrilotriacetate removal and microbial acclimation in activated sludge

The effect of water hardness on microbial acclimation to the removal of nitrilotriacetate (NTA) in the wastewater treatment process was examined in 4 laboratory-scale activated sludge reactors. Consistent high removal (i.e. >90%) was observed in all 4 reactors after acclimation occurred. Removals of greater than 60% of added NTA after 8 days and greater than 90% after 15 days were observed in a continuously fed, hard water (250 mg l⁻¹ as CaCO₃) reactor. In soft water (50 mg l⁻¹ as CaCO₃) comparable removals were observed after 20 and 28 days respectively. In 24 h, semi-continuous activated sludge reactors (24 h, fill-and-draw type) removal was greater in hard water than in soft water initially, but was greater than 95% in both hard and soft water after 4 weeks.The proportion of bacteria in the activated sludge with the ability to utilize NTA increased approx. 100-fold during the acclimation period. This proportion increased faster in hard water than in soft water and faster in semi-continuous activated sludge reactors than continuous activated sludge reactors.Ultimate biodegradation of ¹⁴C[U]NTA was greater than 85% in both hard and soft water acclimated units. Accumulation of ¹⁴C in the sludge solids was negligible (<1%).     

A/A/MBBR工艺处理混合污水的脱氮除磷中试研究

采用A/A/MBBR工艺处理由粪便液和生活污水组成的混合污水,试验条件:填料投配比为20%,好氧池1和好氧池2中的填料体积比为1:3,好氧池的水力停留时间为5 h,混合液回流比为120%,污泥回流比为60%,泥龄为6 d,好氧池的溶解氧为3.0 mg/L,温度为16～20℃.系统稳定运行一个月的结果表明:脱氮除磷效果及对有机物的去除效果均稳定而良好,出水氨氮、总氮、总磷和COD平均浓度分别为0.3、12.9、0.35和36.22 mg/L,均达到了国家一级A排放标准.     

多点交替进水五箱一体化活性污泥法脱氮除磷研究

为了获得较高的氮、磷去除效率，在UNITANK工艺的基础上，开发了一种新型的城市污水脱氮除磷工艺——多点交替进水五箱一体化活性污泥法，并在南京某污水处理厂开展了中试研究。连续一年的稳定运行表明，在进水COD、BOD5、TP、NH3-N、TN分别为110～430、52～130、2．2-6．1、15～41、17-50mg／L的情况下，出水水质可稳定地达到《城镇污水处理厂污染物排放标准》（GB 18918-2002）的一级A标准．除磷率和脱氧率分别可达90％和70％以上．     

25 years of the AMTREAT® process treating high‐strength ammonia liquors

Over the last 30 years, a number of biological treatment processes have emerged for treating high‐strength ammonia liquors arising from the dewatering of anaerobic digestate. The AMTREAT® process was the first process to become established and recognised as a viable and reliable process to treat these high‐strength ammonia liquors. The process is a high‐rate activated sludge plant supplied by ACWA Services Ltd. The first full‐scale plant was installed in 1995, treating centrate produced when dewatering anaerobically digested sludge. The process is a compact, high‐rate ammonia treatment system, which has a relatively small footprint compared to conventional activated sludge treatment processes. Originally designed to fully nitrify dewatering ammonia liquors by controlling the environmental conditions of the treatment reactor, the process has evolved first to include alkalinity recovery and subsequently to offer total nitrogen removal. This paper discusses the development of the AMTREAT® process from its initial development in 1992, to the modern day third generation plants which achieve typical achieve ammonia removal exceeding 99% and total nitrogen removal in excess of 80%.     

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.     

Effectiveness of an alternating aerobic, anoxic/anaerobic strategy for maintaining biomass activity of BNR sludge during long-term starvation

The effectiveness of an aerobic, anoxic/anaerobic strategy for maintaining the activity of activated sludge performing biological nitrogen and phosphorus removal during long-term starvation is investigated. A lab-scale sequencing batch reactor (SBR) treating abattoir wastewater and achieving high-levels (>95%) of nitrogen, phosphorus and COD removal was used. The reactor was put twice into a so-called "sleeping mode" for a period of 5-6 weeks when the abattoir, where the wastewater was sourced, was closed down for annual maintenance. The "sleeping mode" operation consisted of 15 min aeration in a 6 h SBR cycle. The sludge was allowed to settle in the remaining time of the cycle. The decay rates for ammonia oxidising bacteria (AOB) and nitrite oxidising bacteria (NOB) were determined to be 0.017 and 0.004 d(-1), respectively. These decay rates correlated well with AOB and NOB population quantified using molecular techniques (FISH). There was negligible phosphate accumulation in the reactor during the first 1-2 weeks of starvation, which was followed by a linear net release of phosphate in the remaining 4-5 weeks at a very slow rate of 1-2 mgP gVSS(-1)d(-1). A sudden decrease in the aerobic activities of polyphosphate accumulating organisms (PAOs), observed via anaerobic/aerobic batch tests, occurred after 2 weeks of starvation. This correlated with a dramatic increase of several metal ions in the liquid phase. The underlying reasons are not clear. A resuscitation period with a gradual increase of the wastewater load was applied during the re-startup of the reactor after both "sleeping mode" periods. Each time, the performance of the reactor in terms of nitrogen and phosphorus removal fully recovered in 4 days.     

高浓度氨氮生活污水对UCT工艺系统的影响及对策

研究了高浓度氨氮城市生活污水对UCT工艺的影响及相应对策。结果表明,采用UCT工艺处理高浓度氨氮城市生活污水,经过较长时间的污泥驯化和运行调节,系统能达到最佳运行状态,CODcrBOD5NH3-N、TN和TP去除率分别达到88．8％,97．2％,96．2％,85．7％和51．1％,TP需要进一步进行物化处理;UCT工艺的脱氮除磷效率较高,对高浓度氨氮城市生活污水基本可以达到理想的处理效果;高浓度氨氮城市生活污水对活性污泥有明显的冲击,污泥驯化培养需要较长的时间;为提高系统的处理效率可增加好氧区的曝气量,但会对活性污泥产生明显的影响,使出水CODcr和SS含量偏高;高浓度氨氮城市生活污水对UCT工艺脱氮除磷效果有明显的影响,好氧区停留时间、曝气量、硝化液回流比和碳源成为影响因素,可在这些方面加以调节。     

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.     

二级串联人工湿地处理农村污水的脱氮除磷研究

采用二级串联潜流式人工湿地系统对太湖地区农村生活污水进行了脱氮除磷的试验研究。结果表明，在夏季，当进水容积负荷为400L／d时，人工湿地系统对NH4^＋ -N、TN和TP的去除率分别为83％、80％和83％，相应的污染物削减量分别为4772、5463和524mg／d；在冬季，当进水容积负荷为240L／d时，人工湿地系统对NH4^＋ -N、TN和TP的去除率分别为90％、90％和94％，相应的污染物削减量分别为7751、8893和732mg／d；降低进水容积负荷可延长系统的水力停留时间，有利于保持人工湿地系统的除污效率；二级湿地采用粒径较小的填料有助于维持系统对NH4^＋ -N、TN和TP去除效果的稳定性，该工艺可有效去除太湖流域农村生活污水中的氮、磷污染物。     

Simultaneous methanogenesis and denitrification of pretreated effluents from a fish canning industry

A lab-scale hybrid upflow sludge bed-filter (USBF) reactor was employed to carry out methanogenesis and denitrification of the effluent from an anaerobic industrial reactor (EAIR) in a fish canning industry. The reactor was initially inoculated with methanogenic sludge and there were two different operational steps. During the first step (Step I: days 1-61), the methanogenic process was carried out at organic loading rates (OLR) of 1.0-1.25 g COD l-1 d-1 reaching COD removal percentages of 80%. During the second step (Step II: days 62-109) nitrate was added as KNO3 to the industrial effluent and the OLR was varied between 1.0 and 1.25 g COD l-1 d-1. Two different nitrogen loads of 0.10 and 0.22 g NO3(-)-N l-1 d-1 were applied and these led to nitrogen removal percentages of around 100% in both cases and COD removal percentages of around 80%. Carbon to nitrogen ratio (C:N) in the influent was maintained at 2.0 and eventually it was increased to 3.0, by means of glucose addition, to control the denitrification process. From these results it is possible to establish that wastewater produced in a fish canning industry can be used as a carbon source for denitrification and that denitrifying microorganisms were present in the initially methanogenic sludge. Biomass productions of 0.23 and 0.61 g VSS:g TOC fed for Steps I and II, respectively, were calculated from carbon global balances, showing an increase in biomass growth due to denitrification.     

The luxury uptake phenomenon for removal of phosphates from municipal wastewater

Batch experimental studies were conducted to qualitatively assess the Luxury Uptake mechanism and relevant parameters for removal of phosphates from municipal wastewaters by activated sludge. The experiments were conducted with return activated sludge and primary effluent samples from the Bonnybrook Sewage Treatment Plant. Calgary. Alberta. Canada.Aeration rates. aeration time and return sludge/primary effluent ratio were shown to be important parameters affecting biological phosphate removal. High phosphate removals in excess of growth requirements, demonstrated in the laboratory indicate Luxury Uptake by sludge microorganisms. The controversial findings of the Carbon Limitation and Calcium Precipitation Theories were not applicable in this case.