污水生物处理脱氮工艺的温室气体排放比较

污水生物处理是一个较大的温室气体(greenhouse gas,GHG)分散排放源,其中生物脱氮过程对GHG排放的贡献较多。根据污水处理脱氮过程的机理及物料平衡,分别分析比较了传统硝化反硝化、同步硝化反硝化、短程硝化反硝化、厌氧氨氧化4种污水生物处理脱氮工艺中GHG产生的机理与排放量。结果表明,短程硝化反硝化工艺的N2O产量较高,厌氧氨氧化工艺及同步硝化反硝化工艺的GHG排放量较低。     

垃圾渗滤液对厌氧氨氧化混培菌活性的影响研究

采用厌氧复合床,经自养型反硝化过程转化,成功启动了厌氧氨氧化反应器,共耗时165d。反应器启动成功后,容积负荷达到了0.17kg总氮/(m3.d),NO2--N与NH+4-N去除率分别为100%和93%。在此基础上,研究了垃圾渗滤液的亚硝化出水对厌氧氨氧化混培菌活性的影响。研究结果表明:在低质量浓度基质(NH+4-N～60mg/L,NO2--N～60mg/L)条件下,垃圾渗滤液亚硝化出水对厌氧氨氧化反应产生了微弱的影响,氨氮的平均抑制率为10.73%,亚氮的平均抑制率为11.71%。     

亚硝酸型硝化-厌氧氨氧化联合工艺处理"中老龄"垃圾渗滤液

亚硝酸型硝化和厌氧氨氧化有机结合构成的新型全程自养生物脱氮技术为处理高氨氮和低C/N的"中老龄"渗滤液提供了新的思路.主要针对系统内部能否实现稳定的亚硝酸氮自给和厌氧氨氧化反应器的启动这两个关键条件进行研究.结果表明,在氨氮负荷率(ALR)为0.069～0.284 3 gNH3-N/(gVSS·d)条件下,前置亚硝酸型硝化反应器(SBR)能实现稳定的亚硝酸氮积累,出水NO-2-N/NH3-N在1.45左右,NO-2-N/NO-x-N大于90%.而且,接种前置SBR中具有硝化活性的污泥用作厌氧氨氧化反应器(UASB)的接种污泥,可以加快反应器的成功启动.在进水氨氮和亚硝酸氮浓度不超过250 mg/L的条件下,厌氧氨氧化反应器稳定运行时NH3-N和NO-2-N的去除率分别可达到80%和90%左右.     

碳氮比对分段进水多级A/O工艺脱氮效果的影响研究

以实际生活污水为处理对象,考察了进水碳氮比(C/N)为4～8时对多级A/O系统生物脱氮效果的影响,研究了多级A/O系统中COD、NH3-N、NO3--N、NO2--N、TN的沿程变化规律.结果表明,进水C/N对多级A/O系统去除COD及NH3-N影响不明显,COD去除率稳定在 85.2％～94.6％,平均去除率为89.2％,氨氮去除率始终保持在93.0％～99.4％,平均去除率为96.5％,系统具有良好的硝化能力.进水C/N对反硝化脱氮影响明显,系统的反硝化作用随C/N的增大有所增强,在C/N为8时,第一级反硝化程度达到91.1％,接近完全反硝化,硝化程度逐级降低,第三级时为39.3％ ;TN去除率在C/N为4、6、8的工况下分别为44.7％、68.9％和87.3％.     

水解酸化—两级接触氧化—砂滤工艺处理氮肥生产废水

氮肥生产废水氨氮含量高、C:N低,采用水解酸化-两级接触氧化工艺对其进行处理.为了提高氮的去除率,投加甲醇的同时按回流比1:1将接触氧化池出水回流至水解酸化池.工程实践表明,CODCr去除率可达92.1%,氨氮去除率可达98.7%,各项出水指标均达到<城镇污水处理厂污染物排放标准>(Gt3 18918-2002)二级标准.     

基于能源循环利用的污水处理工艺研究

从城市污水处理技术的革新和污水自身能源的开发利用两方面入手,开发了一套能源自给型自养脱氮污水处理新工艺,即厌氧消化-短程硝化-厌氧氨氧化组合工艺,并对该工艺处理生活污水过程中碳的回收利用和氮的去除进行了详细的试验研究。结果表明,该工艺在回收利用污水中碳源、自养脱氮等方面均具有较强的优势。试验过程中以城市生活污水为原水,可实现COD和TN的去除率达89.9%和90.1%,甲烷产率达0.122 L/g COD,系统出水COD和TN低至31.4mg/L和2.5mg/L。原污水中85.1%的COD在厌氧消化段被甲烷化,89.6%的氮被自养去除。研究过程中跟踪监测了系统中碳素和氮素的全程变化及转化,并对各处理单元的影响及关键控制因素进行了详细的分析。     

基于短程反硝化和厌氧氨氧化的城镇污水处理新工艺

厌氧氨氧化（ANAMMox）是迄今为止最具有可持续性的污水脱氮途径。但厌氧氨氧化用于城镇污水时却遭遇到亚硝酸盐难以获取的困境。为此提出将反硝化进行到一半,积累亚硝酸盐作为厌氧氨氧化反应电子受体。据此提出了以短程反硝化和厌氧氨氧化联用为核心的城镇污水脱氮除磷新工艺。对该工艺的可行性进行了分析并提出了今后的研究方向。     

多级生物滤池工艺脱氮效能研究

为实现BAF工艺的高效稳定脱氮,采用了外加碳源的后置反硝化三级BAF工艺(C+N+DN).研究了水温、污染物负荷、硝化液回流等条件下低碳氮比生活污水的脱氮效果.结果表明,在无硝化液回流的条件下,水温高于23℃时,系统具有高效稳定的脱氮效果,出水NH3-N稳定低于5 mg/L;水温低于23℃时,系统出水NH3-N明显升高.当水温为12～23℃时,采取50%硝化液回流并降低负荷后,硝化和反硝化效果明显提高,C柱和N柱对NH3-N和TN的去除率分别提高了19%和22%,最终出水中NH3-N与TN稳定达到<城镇污水处理厂污染物排放标准>(GB18918-2002)一级A标准.     

常温亚硝化—厌氧氨氧化工艺对淀粉废水生物脱氮的研究

采用常温亚硝化—厌氧氨氧化工艺对淀粉废水生物处理出水进行生物脱氮处理,在SBR亚硝化反应器和气提式亚硝化反应器中均实现了稳定的半亚硝化反应。亚硝化—厌氧氨氧化工艺正常运行时,全流程总氮去除率基本维持在80%左右,最高达85.5%。一级亚硝化反应进水容积负荷为0.20kg/(m3·d),平均HRT为1.11d。厌氧氨氧化平均总氮进水容积负荷为1.11kg/(m3·d),最高达1.61kg/(m3·d);平均总氮去除负荷为0.83kg/(m3·d),最高去除负荷达1.29kg/(m3·d);平均HRT为0.20d。淀粉工业废水生物处理后出水中的有机物对亚硝化和厌氧氨氧化反应均未产生显著影响,所含过多的悬浮物和胶体物对亚硝化—厌氧氨氧化反应器存在潜在影响。     

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。     

Anaerobic digestion elutriated phased treatment of piggery waste.

The performance of a novel high-rate anaerobic process, the anaerobic digestion elutriated phased treatment (ADEPT) process, for treating a slurry-type piggery waste (55 g COD/L and 37 g TS/L) was investigated. The ADEPT process consists of an acid elutriation slurry reactor for hydrolysis and acidification, followed by an upflow anaerobic sludge bed reactor for methanification. This process provides stable and high system performance with short HRT (7.4 d) and better effluent quality (2 g SCOD/L and 0.68 g VSS/L) due to the alkaline pH condition for hydrolysis/acidification phase, high refractory solids removal and ammonia toxicity reduction. The optimum pH and HRT for hydrolysis/acidogenesis of the piggery waste were 9 and 5 days at both 35 degrees C and 55 degrees C conditions. The hydrolysis and acidification rate in the mesophilic reactor were 0.05 d(-1) and 0.11 d(-1), meaning that hydrolysis was a limiting step. SCOD production by the hydrolysis was about 0.26 g SCOD/g VS(fed) (3.6 g SCOD/g VS reduction). Methane production and content in the system were 0.3 L CH4/g VS(fed) (0.67 L CH4/g VS destroyed) and 80%, respectively, corresponding to 0.23 L CH4/g COD removal (@STP).     

Sequenced anaerobic-aerobic treatment of high strength, strong nitrogenous landfill leachates.

As a first step in treatment of high strength, strong nitrogenous landfill leachates (total COD--9.66-20.56 g/l, total nitrogen 780-1,080 mg/l), the performance of laboratory UASB reactors has been investigated under sub-mesophilic (19+/-3 degrees C) and psychrophilic (10+/-2 degrees C) conditions. Under hydraulic retention time (HRT) of around 1.2 days, when the average organic loading rate (OLR) was around 8.5 g COD/l/day, the total COD removal accounted for 71% (on average) for sub-mesophilic regime. The psychrophilic treatment conducted under the average HRT of 2.44 days and the average OLR of 4.2 g COD/l/day showed an average total COD removal of 58% giving effluents more suitable for subsequent biological nitrogen removal. Both anaerobic regimes were quite efficient for elimination of heavy metals by concomitant precipitation in the form of insoluble sulphides inside the sludge. The subsequent submesophilic aerobic-anoxic treatment of submesophilic anaerobic effluents led to only 75% of total inorganic N removal due to COD deficiency for denitrification created by too efficient anaerobic step. On the contrary, psychrophilic anaerobic effluents (richer in COD compared to the submesophilic ones) were more suitable for subsequent aerobic-anoxic treatment giving the total N removal of 95 and 92% at 19 and 10 degrees C, respectively.     

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％.     

深度处理维生素制药废水的中试研究

维生素制药废水经过初步生化处理后,出水水质无法满足要求,具有难降解、COD和氨氮浓度高的特点,针对这些特点,本文采用"强化复合曝气水解酸化→高效厌氧复合反应→流离生物接触氧化"连续工艺深度处理维生素制药废水,研究其可行性。处理规模为7.2 m3/d的中型试验结果表明:强化复合曝气水解酸化能使进水B/C值由0.33提高到0.48,提高下一步生化反应的处理效率,当进水CODCr的浓度为150～641 mg/L,氨氮浓度为6～115 mg/L时,平均去除率分别达到84.28%、93.8%,出水COD浓度小于50mg/L,氨氮浓度小于5 mg/L,出水水质能够达到《城镇污水处理厂污染物排放标准》GB18918-2002中的一级A指标,该连续工艺深度处理此类废水具有可行性和稳定性。     

内循环生物流化床处理N、P废水的试验研究

采用内循环生物流化床系统,进行N、P废水的试验研究,通过控制曝气时间和溶解氧浓度,能同时达到脱氮除磷的效果.对于N、P废水,COD在352～1048 mg/L,TN在46.9～76.4 mg/L,TP在5.8～14.4 mg/L时,COD、TN、TP去除率分别为92%、80%、93%,处理后的水可达到国家二级排放标准.     

Development and optimisation of VFA driven DEAMOX process for treatment of strong nitrogenous anaerobic effluents.

The recently proposed DEAMOX (DEnitrifying AMmonium OXidation) process combines the anammox reaction with autotrophic denitrifying conditions using sulphide as an electron donor for the production of nitrite from nitrate within an anaerobic biofilm. This paper firstly presents a feasibility study of the DEAMOX process using synthetic (ammonia + nitrate) wastewater where sulphide is replaced by volatile fatty acids (VFA) as a more widespread electron donor for partial denitrification. Under the influent N-NH+4/N-NO3(-) and COD/N-NO3(-) ratios of 1 and 2.3, respectively, the typical efficiencies of ammonia removal were around 40% (no matter whether a VFA mixture or only acetate were used) for nitrogen loading rates (NLR) up to 1236 mg N/l/d. This parameter increased to 80% by increasing the influent COD/N-NO3(-) ratio to 3.48 and decreasing the influent N-NH4 +/N-NO3(-) ratio to 0.29. As a result, the total nitrogen removal increased to 95%. The proposed process was further tested with typical strong nitrogenous effluent such as reject water (total N, 530-566 mg N/l; total COD, 1530-1780 mg/l) after thermophilic sludge anaerobic digestion. For this, the raw wastewater was split and partially ( approximately 50%) fed to a nitrifying reactor (to generate nitrate) and the remaining part ( approximately 50%) was directed to the DEAMOX reactor where this stream was mixed with the nitrified effluent. Stable process performance up to NLR of 1,243 mg N/l/d in the DEAMOX reactor was achieved resulting in 40, 100, and 66% removal of ammonia, NOx(-), and total nitrogen, respectively.     

ABR反应器对垃圾渗滤液的处理试验研究

ABR工艺在处理垃圾渗滤液中具有其他厌氧生物反应器所达不到的优点。尤其是对B/C低、氨氮浓度高、COD浓度高的废水处理,通过调节回流比、HRT、碱度等参数后,可以取得很好的处理效果。在本次实验中,HRT控制在18h后明显提高的垃圾渗滤液的可生化性及C/N,使ABR出水CODcr去除率达到75%,C/N为6.72,对后续好氧反应起到了重要作用。在调控一定回流比后,为提供厌氧氨氧化所需的电子受体NO-3和NO-2实现脱氮。反应器在经过120d的培养驯化,氨氮进水为460mg/L,ABR对氨氮的去除率稳定在80%。不同格室的厌氧颗粒污泥都得到很好的驯化并在其合适的环境中发挥各自的功能。     

Simultaneous removal of ammonium-nitrogen and sulphate from wastewaters with an anaerobic attached-growth bioreactor.

Some industrial wastewaters may contain ammonium-nitrogen and/or sulphate, which need to be removed before their discharge into natural water bodies to eliminate their severe pollution. In this paper, simultaneous removal of ammonium-nitrogen and sulphate with an anaerobic attached-growth bioreactor of 3.8 L incubated with sulphate reducing bacteria (SRB) was investigated. Artificial wastewater containing sodium sulphate as electron acceptor, ammonium chlorine as electron donor and glucose as carbon source for bacteria growth was used as the feed for the bioreactor. The loading rates of ammonium-nitrogen, sulphate and COD were 2.08 gN/m3 x d, 2.38 gS/m3 x d, 104.17 gCOD/m3 x d, respectively, with a N/S ratio of 1:1.14. The results demonstrated that removal rates of ammonium-nitrogen, sulphate and COD could reach 43.35%, 58.74% and 91.34%, respectively. Meanwhile, sulphur production was observed in effluent as well as molecular nitrogen in biogas, whose amounts increased with time substantially, suggesting the occurrence of simultaneous removal of ammonium-nitrogen and sulphate. This novel reaction provided the possibility to eliminate ammonium-nitrogen and sulphate simultaneously with accomplishment of COD removal from wastewater, making wastewater treatment more economical and sustainable.     

Performance evaluation of the BioCAST technology: a new multi-zone wastewater treatment system

A new wastewater treatment technology, called BioCAST, has been designed and developed for high rate and simultaneous removal of organic carbonaceous compounds as well as nitrogen and phosphorus, along with reduced sludge generation. The treatment system has two interlinked reactors containing four independent zones with different environmental conditions of aerobic, microaerophilic, anoxic and anaerobic for the biological treatment of wastewater, as well as two clarification zones and a filtration unit for solid-liquid separation. The treatment system contains suspended as well as fixed-film microorganisms. The performance evaluation of the BioCAST system was carried out at organic loading rates of 0.95 to 1.86 kg/m(3) d, and nitrogen and phosphorus loading rates of 0.02 to 0.08 kg/m(3) d and 0.014 to 0.02 kg/m(3) d, respectively. The results demonstrated high removal efficiencies of carbon and nitrogen throughout the operation period, reaching 98.9 and 98.3%, respectively. Phosphorus removal efficiency was lower than 50% during the first 160 days of operation but it increased with the increase of nitrogen loading rate above 0.05 kg/m(3) day and concomitant reduction of C/N ratio below 15. Phosphorus removal efficiency reached 94.1%, producing an effluent concentration of 1.4 mg/L after 225 days of operation. The overall biomass yield based on the consumed COD was 3.7%.     

Upgrading of Florence wastewater treatment plant: co-digestion and nitrogen autotrophic removal.

In recent years a completely autotrophic nitrogen removal process based on Anammox biomass has been tested in a few European countries in order to treat anaerobic supernatant and to increase the COD/N ratio in municipal wastewater. This work reports experimental results on a possible technical solution to upgrade the S. Colombano treatment plant which treats wastewater from the Florentine urban area. The idea is to use 50% of the volume of the anaerobic digester in order to treat external sewage sludge (as septic tank sludge) together with waste activated sludge and to treat the resulting effluent on a SHARON-ANAMMOX process in order to remove nitrogen from the anaerobic supernatant. Anaerobic co-digestion, tested in a 200 L pilot plant, enables low cost treatment of septic tank sludge and increases biogas production; however, it also increases the nitrogen load re-circulated to the WWTP, where nitrogen removal efficiency is already low (<50%), due to the low COD/N ratio, which limits predenitrification efficiency. Experimental results from a SHARON process tested in a lab-scale pilot plant show that nitrite oxidising bacteria are washed-out and steady nitrite production can be achieved at retention times in the range 1 - 1.5 days, at 35 degrees C. In a lab-scale SBR reactor, coupled with a nitration bioreactor, maximum specific nitrogen removal rate under nitrite-limiting conditions (with doubling time equal to about 26 days at 35 degrees C) was equal to 0.22 kgN/kgSSV/d, about 44 times the rate measured in inoculum Anammox sludge. Finally, a cost analysis of the proposed upgrade is reported.