好氧颗粒污泥反应器快速启动及除碳脱氮试验

为快速启动好氧颗粒污泥反应器,在SBR反应器中同时接种硝化污泥和厌氧颗粒污泥,控制反应条件,温度23~25℃,pH值7.5~8.5,DO质量浓度1.5 mg/L左右,15 d即完成反应器快速启动。形成的好氧颗粒污泥粒径1.5~2.5 mm,SVI值54 mL/g。颗粒污泥结构紧密,沉降性能良好。反应器连续运行40多天,改变进水COD及NH4+-N浓度,COD和NH4+-N去除率均能稳定在80%以上,反应器内发生了同步硝化反硝化过程。     

潜流湿地短程硝化反硝化强化脱氮研究

为探索人工湿地系统短程硝化反硝化脱氮作用对微污染水体脱氮性能的提升效果及影响因素,构建两级垂直流潜流湿地系统,对比分析了间歇进水、同步回流、预曝气等运行方式下的净水效果及含氮污染物的转化规律,结果表明:进水低碳氮比条件下,系统对COD_Cr和NH■-N的去除率稳定在60.5%～64.3%和90%以上;通过水位/水量调节方式强化湿地内部自然富氧作用,实现TN去除效果增长8%～10%,亚硝化率呈升高趋势,NO■-N的累积现象有所改善;氨氧化细菌（AOB）和氨氧化古菌（AOA）群落分布一致性和优势群菌丰度显著提升,反硝化细菌（nirS）优势种群分布同时得到改善,水位/水量调控的运行方式可以提升短程硝化效率,为反硝化反应提供更充足的底质和溶解氧条件,强化湿地系统对微污染水体的短程硝化反硝化脱氮作用。     

DO对短程同步硝化反硝化除磷工艺的影响

针对碳源偏低的城市污水,采用序批式活性污泥法研究DO对短程同步硝化反硝化除磷工艺的影响,同时对短程同步硝化反硝化和反硝化除磷的机理进行探讨.试验表明:控制DO浓度可在同一个反应器内既实现短程同步硝化反硝化反应又达到反硝化除磷的效果.综合考虑COD、NH4+-N、TN、TP的出水浓度达到一级A排放标准,得出最佳的DO控制...     

好氧反硝化生物脱氮研究进展

好氧反硝化新型生物脱氮理论的诞生,克服了传统生物脱氮工艺存在的不足,简化了流程,节省了投资和运行费用,提高了脱氮效率.初步探讨了好氧反硝化机理,从不同角度做了理论分析;阐述了有关好氧反硝化脱氮的研究进展;并对好氧反硝化应用前景做了展望,提出了好氧反硝化今后的研究方向重点应放在对好氧反硝化菌的筛选和驯化上,对于好氧反硝化的发生条件、反应中间产物及其反应机理等方面需要进行深入研究.     

DO对短程同步硝化反硝化除磷工艺的影响

针对碳源偏低的城市污水,采用序批式活性污泥法研究D0对短程同步硝化反硝化除磷工艺的影响,同时对短程同步硝化反硝化和反硝化除磷的机理进行探讨。试验表明：控制DO浓度可在同一个反应器内既实现短程同步硝化反硝化反应又达到反硝化除磷的效果。综合考虑COD、NHg—N、TN、TP的出水浓度达到一级A排放标准,得出最佳的D0控制范围。当D0浓度在0．5～1．0mg／LU时．COD的去除率达到93％～94％,Nil,＋一N的去除率为97％～98％,TN的去除率达到85％一96％,TP的去除率为91％～93％。     

垃圾渗滤液曝气生物处理中好氧氧反硝化现象探讨

通过试验,对垃圾渗滤液间歇曝气(曝气时D0为5.5～7 mg/L;停止时DO为1.1～5.5 mg/L),在仅有有机碳、无机氮的条件下进行好氧反硝化脱氮研究.试验结果表明:间歇曝气条件下,渗滤液中存在的好氧反硝化土著微生物茵落会成为优势菌种,在溶解氧充足的条件下,能够发生好氧反硝化反应,使得硝化和反硝化可以真正同步进行;外加碳源不仅是厌氧反硝化所必须的,同样也是好氧反硝化的必要条件;好氧反硝化的最佳曝气方式为间歇曝气.     

污水处理厂反硝化除磷研究及实践

结合苏州娄江污水处理厂生产运行实践,研究了改良型一体化交替反应池在实现良好反硝化除磷条件下的运行工况.实践表明,提高反硝化除磷的关键是要有充足的硝酸盐氮为反硝化聚磷菌(DPB)提供电子受体,当NO-2N浓度在5 mg/L以上时,可以实现较好的反硝化除磷;当SRT为12～14 d时,反硝化除磷和系统脱氮除磷效果最好,生物除磷运行成本较低.此外,进水COD/TP、好氧池DO、厌氧池MLSS以及SRT也是影响一体化反应池生物除磷的主要因素.针对雨季低负荷运行除磷效果不理想的现象,提出了相应的工况运行措施.     

天然水体氮自净过程及硝化所需溶解氧源试验验证

通过试验验证了天然水体中确实存在氮的自然净化过程和同步硝化/反硝化途径。在氮与有机物浓度较低时,遮光阻断藻类光合作用试验表明,大气复氧足以使试验水质条件下的氮和有机物完全氧化。然而,有机物过早消耗对硝化后产生的硝酸氮再行反硝化作用不利。反硝化反应彻底进行可以通过外加碳源方式实现。COD初始浓度较高会引起异养菌对氧的大量消耗,使本来数量就处于劣势的硝化细菌的硝化反应受阻。     

氨氮废水处理过程中的好氧反硝化研究

采用序批式反应器处理氨氮废水 ,试验结果验证了好氧反硝化的存在 ,好氧反硝化脱氮能力随混合液溶解氧浓度的提高而降低 ,当溶解氧浓度为 0 5mg/L时 ,总氮去除率可达到 6 6 0 %。并结合理论分析 ,对好氧反硝化的机理进行了探讨     

一体式连续流A/O-MBR脱氮除磷试验研究

采用一体式厌氧/好氧膜生物反应器(A/O-MBR)处理模拟生活污水,溶解氧(DO)浓度分别控制在小于0.7mg/L,1±0.3mg/L,2±0.3mg/L和大于0.3mg/L下,以DO为2±0.3mg/L时,反应器对污染物的去除能力最强,COD、NH4+-N、TN、PO43--P的去除率分别可达91.4%,89.6%,88.7%和92.3%。在该DO条件下,对C/N和C/P对污染物去除效果的影响进行了研究。结果表明:当进水C/N在14～24之间C/P在70～120之间变化时,氨氮及总氮去除率随着C/N的增大而增大,而对COD及磷的影响不大。当进水C/N=8,C/P=40时,脱氮效果明显下降。说明即使控制适宜的溶解氧,在碳源不足的情况下对氮也无法达到较好的去除,表明碳源是否充足是影响同步硝化反硝化的关键因素。     

塔式生物滤池处理城市污水的研究

尽管目前塔式生物滤池在城市污水处理中运用较少 ,但在有可资利用的地形时它可达到少动力或无动力运行 ,有较大的优势。研究了塔式生物滤池的工作参数及其处理特点。     

Nitrogen removal in an upflow sludge blanket (USB) reactor combined by aerobic biofiltration systems.

A new nitrogen removal process (up-flow sludge blanket and aerobic filter, USB-AF) was proposed and tested with real sewage. In the USB reactor, the larger part of influent organic and nitrogen matters were removed, and ammonia was effectively oxidized in the subsequent aerobic filter. The role of the aerobic filter was to convert ammonia into nitrate, an electron acceptor that could convert soluble organic matters into volatile suspended solid (VSS) in the USB. The accumulated as well as influent VSS in the USB was finally degraded to fermented products that were another good carbon source for denitrification. Total COD, settleable COD and soluble COD in the raw sewage were 325, 80 and 140 mg/l, respectively. Most unsettleable COD as well as some SCOD in the influent was successfully removed in the USB. TCOD removal in the anoxic filter was by denitrification with the recycled nitrate. Low COD input to the aerobic filter could increase nitrification efficiency, reduce the start-up period and save the aeration energy in the USB-AF system. About 95% of ammonia was nitrified in the aerobic filter with no relation to the influent ammonia concentration. Denitrification efficiency of the recycled nitrate in the anoxic filter was about 85, 83, and 72% at recycle ratios of 100, 200, and 300%, respectively. T-N removal efficiency was 70% at recycle ratio of 300%.     

Feasibility study on the removal of nitrous compounds with a hollow-fiber membrane biofilm reactor.

The objective of this study was to develop an integrated nitrogen treatment system using autotrophic organisms. A treatment system consists of an aerobic hollow-fiber membrane biofilm reactor (HfMBR) and anaerobic HfMBR. In the aerobic HfMBR, a mixture gas of air and O2 was supplied through the fibers for nitrification. Denitrification occurred in the anaerobic HfMBR using H2 as the electron donor. The treatment system was continuously operated for 190 days. NH4-N removal efficiencies ranging from 95% to 97% were achieved at NH4-N concentrations of influent ranging from 50 to 100 mg N/L. When glucose was added to the influent, the simultaneous nitrification and denitrification occurred in the aerobic HfMBR, and nitrogen removal rates were changed according to the COD/NH4-N ratio of influent. In the anaerobic HfMBR, autotrophic denitrification using H2 occurred and the removal rates achieved in this study were 23-58 mg N/m2 d. In this study, the achieved removal efficiency was lower than other study findings; however, the result suggested that this hybrid HfMBR system can be used effectively for nitrogen removal in oligotrophic water.     

Multistage wastewater treatment using separated storage driven denitrification and nitrification biofilms.

The feasibility of combining a previously reported storage driven denitrification biofilm, where 80% of influent acetate can be converted to poly-beta-hydroxybutyrate (PHB), with a suitable nitrification reactor, either submerged or trickling filter design, to achieve complete biological nitrogen removal was tested. The reactor system showed the potential of complete biological nitrogen removal of waste streams with a C/N ratio as low as 3.93 kg COD/kg N-NH3 at an overall nitrogen removal rate of 1.1 mmole NH3/L/h. While the efficiency and the rates of nitrogen removal were higher than what is observed in traditional or simultaneous nitrification and denitrification (SND) systems, there were two problems that require further development: (a) the incomplete draining of the reactor caused ammonia retention and release in the effluent, limiting the overall N-removal and (b) pH drifts in the nitrification step slowed down the rate of nitrification if not corrected by appropriate pH adjustment or buffering.     

CASS工艺生物脱氮除磷效果分析

对CASS工艺脱氮除磷效果进行了试验研究,重点研究了温度和回流比对脱氮效果的影响,曝气量对除磷效果的影响。研究结果表明,水温在30℃时系统脱氮效果最好,此时NH3-N去除率在80%左右,TN去除率在70%左右;污泥回流比为25%、50%、100%和200%时,TN去除率分别为50%、58%、62%和70%,增加回流比可以提高脱氮效率;好氧区DO维持在2mg/L和4 mg/L时,TP去除率分别为82%和37%。     

Automatic control of external carbon source addition for nitrogen removal in sewage with low C/N ratios.

For cost-effective nitrogen removal from sewage with low C/N ratios, an automatic control system for the addition of external carbon based on oxidation-reduction potential (ORP) data in an anoxic reactor has been developed. In this study, it was carried out with a pilot-scale modified Bardenpho process. This consisted of anoxic1, aerobic1, anoxic2 and aerobic2 stages with an external recycle ratio of 150% (Q/Qinf), and a media packing ratio of 2.4%-2.9% (v/v) in the aerobic reactor. As a result of applying the automatic control system for the minimization of the external carbon source dosage, the dosage was decreased by about 20%. This estimate was based on ORP compared with a stable dosage of 75 mg/L based on the C/NOx-N ratio of the anoxic influent. It was necessary that the ORP set-value be regulated from -120 mV to -80 mV because influent NH4+-N concentration varied from 12 to 15 mg/L due to rainfall. Correspondingly, the demanded dosages were decreased. Drift of the the real-time value in control system was more stable after changing the ORP set-value from -120 mV to -80 mV.     

Optimisation of storage driven denitrification by using on-line specific oxygen uptake rate monitoring during SND in a SBR.

This study builds on previous experience of maximising the formation of COD as poly-hydroxybutyrate (PHB) and now describes a feedback technique of preserving the use of PHB for denitrification resulting in enhanced nitrogen removal rather than allowing its wasteful oxidation by oxygen. The feedback technique uses on-line SOUR monitoring for detecting the end-point of nitrification and controlling the aerobic phase length accordingly. The laboratory SBR was operated such that all organic substrate (acetate) was rapidly converted to PHB, which then served as the electron donor for nitrogen removal via simultaneous nitrification and denitrification (SND) during the aerobic phase (up to 70% SND). During SBR cycling with a fixed aeration length (240 minutes), PHB was unnecessarily oxidised after ammonium depletion, resulting in little denitrification and poor total nitrogen removal (69%). However, when the aerobic phase length was controlled via the SOUR, up to 1.8 CmM PHB (58 mg L(-1) COD) could be preserved, enabling improved total nitrogen removal (86%). The drop in the SOUR after ammonium depletion was a reproducible event that could be detected even when using raw wastewater and fresh activated sludge. The SOUR-control technique holds promise to build up PHB over a number of SBR cycles. While advanced oxygen-control is used for improved N-removal in several existing WWTPs, this study investigates the importance of oxygen control with relevance to PHB driven SND in sequencing batch reactors.     

倒置A2/O—MBR工艺处理低C/N生活污水脱氮性能研究

合肥塘西河再生水厂采用倒置A/O(缺氧/厌氧/好氧—预缺氧)—MBR工艺处理低C/N城市生活污水.研究了投加碳源前后各生化反应池中有机物及氮元素的变化规律,结果表明未投加外碳源时TN的去除率为52.3％,脱氮效果不理想.通过比较乙酸钠、甲醇和乙酸三种不同外加碳源的脱氮效果,可知乙酸钠反硝化速率最高,效果最好.当乙酸钠作外碳源,投加量为50 mgCOD/L时,TN的去除率明显提高,达到74.5％.此外,还分析了投加外碳源后整个工艺系统内COD、TN物质流动情况,结果表明,缺氧池和厌氧池是COD去除的主要单元体,好氧池对COD的去除贡献增强,体系中的TN去除总量在投加外碳源后有了明显的增加,较未投加外碳源时增加了26.5％.     

Combined partial nitritation/Anammox system for treatment of digester supernatant.

One-year (2004) comprehensive investigations in a semi-industrial pilot plant (5 m3) were carried out with the aim of assessing the influence of operational parameters on the partial nitritation/Anammox system performance. In the system designed as a moving-bed biofilm reactor, the influent nitrogen load to the Anammox reactor was progressively increased and a stable Anammox bacterial culture was obtained. Interaction between subsequent aerobic and anaerobic conditions in the partial nitritation and Anammox reactors, respectively, granted conditions to remove nitrogen through the nitrite route. It implies that the oxygen supply can be limited to a high extent. A control strategy for the partial nitritation step relied on concomitant adjustment of the air supply with a variable influent nitrogen load, which can be monitored by both pH and conductivity measurements. In the Anammox reactor, an influent nitrite-to-ammonium ratio plays a vital role in obtaining efficient nitrogen removal. During the 1-year experimental period, the Anammox reactor was operated steadily and average nitrogen removal efficiency was 84% with 97% as the maximum value.     

Effect of internal recycle rate on the high-strength nitrogen wastewater treatment in the combined UBF/MBR system.

An anaerobic/aerobic system combining an anaerobic upflow-sludge bed filter (UBF) and an aerobic membrane bioreactor (MBR) was operated to enhance organic and nitrogen removal efficiency. The internal recycle rate, which is one of the most important operation factors that affects overall removal efficiency, was varied from 100% to 300% of the influent flow. Under these conditions, the overall removal efficiencies of organic and nitrogen and characteristics of membrane fouling in the combined system treating the synthetic wastewater including high concentration of organics and nutrients were studied. As a result, nitrogen removal efficiency was increased to 67% when the internal recycle rate was 300% of influent flow rate. As the internal recycle ratio increased from 100% to 200%, protein content decreased by 17% and carbohydrate content increased by 12%. However, there was no remarkable difference in total extracellular polymeric substances (EPS) content. At the high recycle rate of 300%, the surface charge of sludge was decreased while hydrophobicity (specific ultraviolet absorbance, SUVA) was increased. The differences in SUVA and surface charge were 11% and 1%, respectively. It is concluded that SUVA and EPS composition were important parameters affecting membrane fouling in the combined system.