小氮肥企业高氨氮废水处理的试验研究

针对小氮肥厂生产废水的排放现状及其对城市污水处理厂的影响 ,在试验的基础上提出了处理高含氨氮废水的空气吹脱—好氧硝化处理工艺 .空气吹脱可有效地去除解吸液中的氨氮 ,氨氮浓度由 1869.3mg/L降至 40 8.3mg/L ,去除率为 78% ;好氧生物硝化可有效地去除混合生产废水中的氨氮 ,氨氮浓度由 2 41mg/L降低为 2 3 .2mg/L ,去除率达 90 % ,达到国家二级排放标准     

Simultaneous carbon and nitrogen removal from high strength domestic wastewater in an aerobic RBC biofilm

High strength domestic wastewater discharges after no/partial treatment through sewage treatment plants or septic tank seepage field systems have resulted in a large build-up of groundwater nitrates in Rajasthan, India. The groundwater table is very deep and nitrate concentrations of 500-750 mg/l (113-169 as NO3(-)-N) are commonly found. A novel biofilm in a 3-stage lab-scale rotating biological contactor (RBC) was developed by the incorporation of a sulphur oxidising bacterium Thiosphaera pantotropha which exhibited high simultaneous removal of carbon and nitrogen in fully aerobic conditions. T. pantotropha has been shown to be capable of simultaneous heterotrophic nitrification and aerobic denitrification thereby helping the steps of carbon oxidation, nitrification and denitrification to be carried out concurrently. The first stage having T. pantotropha dominated biofilm showed high carbon and NH4(+)-N removal rates of 8.7-25.9 g COD/m2 d and 0.81-1.85 g N/m2 d for the corresponding loadings of 10.0-32.0 g COD/m2 d and 1.0-3.35 g N/m2 d. The ratio of carbon removed to nitrogen removed was close to 12.0. The nitrification rate increased from 0.81 to 1.8 g N/m2 d with the increasing nitrogen loading rates despite a high simultaneous organic loading rate. However, it fell to 1.53 g N/m2 d at a high load of 3.35 g N/m2 d and 32 g COD/m2 d showing a possible inhibition of the process. A simultaneous 44-63% removal of nitrogen was also achieved without any significant NO2(-)-N or NO3(-)-N build-up. The second and third stages, almost devoid of any organic carbon, acted only as autotrophic nitrification units, converting the NH4(+)-N from stage 1 to nitrite and nitrate. Such a system would not need a separate carbon oxidation step to increase nitrification rates and no external carbon source for denitrification. The alkalinity compensation during denitrification for that destroyed in nitrification may also result in a high economy.     

Biological nitrogen removal from municipal landfill leachate: low-cost nitrification in biofilters and laboratory scale in-situ denitrification

The slow leaching of nitrogen from solid waste in landfills, resulting in high concentrations of ammonia in the landfill leachate, may last for several decades. The removal of nitrogen from leachate is desirable as nitrogen can trigger eutrophication in lakes and rivers. In the present study, a low-cost nitrification-denitrification process was developed to reduce nitrogen load especially in leachates from small landfills. Nitrification was studied in laboratory and on-site pilot aerobic biofilters with waste materials as filter media (crushed brick in upflow filters and bulking agent of compost in a downflow filter) while denitrification was studied in a laboratory anoxic/anaerobic column filled with landfill waste. In the laboratory nitrification filters, start-up of nitrification took less than 3 weeks and over 90% nitrification of leachate (NH4-N between 60 and 170mg N l(-1), COD between 230 and 1,300 mg l(-1)) was obtained with loading rates between 100 and 130 mgNH4-N l(-1) d at 25 degrees C. In an on-site pilot study a level of nitrification of leachate (NH4-N between 160 and 270 mg N l(-1), COD between 1,300 and 1,600 mg l(-1)) above 90% was achieved in a crushed brick biofilter with a loading rate of 50mg NH4-N l(-1) d even at temperatures as low as 5-10 degrees C. Ammonium concentrations in all biofilter effluents were usually below the detection limit. In the denitrification column. denitrification started within 2 weeks and total oxidised nitrogen in nitrified leachate (TON between 50 and 150mg N l(-1)) usually declined below the detection limit at 25 degrees C, whereas some ammonium, probably originating from the landfill waste used in the column, was detected in the effluent. No adverse effect was observed on the methanation of waste in the denitrification column with a loading rate of 3.8 g TON-N/t-TS(waste) d. In conclusion, nitrification in a low-cost biofilter followed by denitrification in a landfill body appears applicable for the removal of nitrogen in landfill leachate in colder climates.     

应用SBR实现有机废水厌氧氨氧化生物脱氮的研究

采用SBR反应器,以硝化污泥和厌氧氨氧化(ANAMMOX)颗粒污泥的混合污泥为接种污泥,以有机模拟废水为研究对象,进行了厌氧氨氧化生物脱氮工艺研究。结果表明,在控制温度为25℃,水力停留时间为12 d,pH值为7.2～8.5,进水NH4+-N为220 mg/L左右、NO2--N为138 mg/L左右、COD为294 mg/L的条件下成功启动了SBR反应器。在高氨氮、低有机物浓度的条件下,ANAMMOX菌和异养反硝化菌能够实现共存,且ANAMMOX菌仍能成为优势菌属,AN-AMMOX反应是反应器中的主导反应。镜检发现,优势菌尺寸约为1μm,呈圆形或椭圆形,成簇聚生,表面可观察到明显的漏斗状缺口,具有典型的厌氧氨氧化菌特征。污泥中形成了以厌氧氨氧化球状菌为主、其他杆状菌和丝状菌共存的微生物混培体。     

异养硝化菌的分离及其强化活性污泥脱氮效果

为提高水处理过程中的脱氮率，实现好氧条件下对总氮的去除。通过试验分离出一株异养硝化菌，该菌株为白色革兰氏阴性球状菌。将该菌扩大培养后接种于活性污泥系统并进行了处理模拟废水的试验。结果表明：该菌能在好氧条件下分别代谢氨氮、亚硝酸盐氮、硝酸盐氮，并通过好氧反硝化实现对总氮的去除。用该菌株强化的活性污泥系统对以氨氮、亚硝酸盐氮、硝酸盐氮为惟一氮源的模拟废水进行处理，4h的总氮去除率分别为85％、60％、70％。     

MBBR用于南方某污水厂强化脱氮效果分析

浙江某污水厂设计规模为16×10⁴m³/d,采用Bardenpho—MBBR工艺进行升级改造后,生化池出水COD、NH₄⁺-N、TN、TP均值分别为17. 2、0. 37、7. 72、0. 168 mg/L,在不投加碳源的情况下即可达到准Ⅳ类水标准,生物脱氮除磷效果良好。对生化池各功能区沿程采样测定发现,好氧MBBR区对TN的去除率为28%～46%,受到泥浆水冲击后也能保持在15%～22%,系统高效去除TN得益于好氧MBBR区的同步硝化反硝化(SND)作用;由于好氧区的SND现象,平均可以节省0. 23元/m3的碳源费用,年节约碳源费用近1 343. 2万元;生物膜厚度和溶解氧的控制对于稳定表现SND有重要影响;系统中微生物的高通量测序结果显示,悬浮载体上硝化菌丰度为32. 19%、反硝化菌丰度为4. 86%,硝化菌和反硝化菌同时存在为SND现象的产生提供了微观保证;冬季低温时,悬浮载体实际承担了系统近90%的硝化负荷。     

Nitrogen loss and oxygen paradox in full-scale biofiltration for drinking water treatment

The nitrogen loss and DO paradox in full-scale biofiltration for drinking water treatment and the possible pathway responsible for them were investigated. A highly contaminated source water was treated at Pinghu Surface Water Plant using four biofilters, which resulted in a steady removal of NH(4)(+)-N (2.67mg/L), a great DO consumption (8.86 mg/L) and an increase in the concentration of NO(3)(-)-N (1.77mg/L). The nitrogen and DO balances indicated that about 13 NH(4)(+)-N was lost and the actual DO consumption was about 30% lower than the theoretical DO demand if nitrification was regarded as the only pathway to remove NH(4)(+)-N. The analysis of correlation coefficients analysis between several factors and the nitrogen loss suggested that "Aerobic deammonification", the coupling of shortcut nitrification and the anaerobic ammonia oxidation (Anammox) in an aerobic environment, might be the most probable pathways to explain the occurrence of these phenomena. According to this mechanism, about 57% NH(4)(+)-N was removed through complete nitrification and about 21.5% NH(4)(+)-N was incompletely nitrified into NO(2)(-)-N. The latter then involved in Anammox as the electron acceptor with the remaining NH(4)(+)-N as the electron donor. Since the Anammox reaction is anaerobic, the nitrogen loss and DO paradox can be justified.     

Simultaneous organic and nitrogen removal from municipal landfill leachate using an anaerobic-aerobic system

An anaerobic-aerobic system including simultaneous methanogenesis and denitrification was introduced to treat organic and nitrogen compounds in immature leachate from a landfill site. Denitrification and methanogenesis were successfully carried out in the anaerobic reactor while the organic removal and nitrification of NH4+,-N were carried out in the aerobic reactor when rich organic substrate was supplied with appropriate hydraulic retention time. The maximum organic removal rate was 15.2 kg COD/m3 d in the anaerobic reactor while the maximum NH4+-N removal rate and maximum nitrification rate were 0.84kg NH4+-N/m3/d and 0.50kg NO3--N/m3/d, respectively, in the aerobic reactor. The pH range for proper nitrification was 6-8.8 in the aerobic reactor. The organic compounds inhibited nitrification so that the organic removal in the anaerobic reactor could enhance the nitrification rate in the following aerobic reactor. The gas production rate was 0.33 m3/kg COD and the biogas compositions of CH4, CO2, and N2 were kept relatively constant, 66-75, 22-32, and 2-3%, respectively.     

固定化氨氧化菌短程硝化的启动研究

采用亲水性玻璃态单体,应用辐射技术制备生物相容性高分子共聚物载体,使用固定化细胞增殖技术对氨氧化菌进行固定化,并以流化床为生物反应器,采用SBR运行方式对人工配水进行短程硝化的启动研究.结果表明:当进水氨氮浓度为100、75、50和25mg/L时,对氨氮的的去除率分别为98.6%、99.1%、98.8%和99.8% ,亚硝化率分别为 98.6%、94,5%、95.2%和94.7%:对氨氮的去除速率由开始时的10.6mg/(L·d)提高到25.7mg/(L·d),耗氧速率(OUR)则由0.37mg/(L·d)提高到1.12mg/(L·d).可见,该方法具有启动速度快、亚硝化程度高、容易控制等优点.     

MBR中DO对同步硝化反硝化的影响

膜生物反应器（MBR）中,在DO为1mg/L左右,MLSS为8000-9000mg/L,温度为24℃,进水pH值为7.2,COD、NH3-N分别为523-700mg/L和17.24-24mg/L的相对稳定条件下,对COD、NH3-N、TN的去除率分别为96%、95%、92%。详细分析了在控制DO的条件下,MBR发生同步硝化、反硝化的原因,并提出了在单级好氧反应器中控制DO可发生短程硝化一反硝化生物脱氮的机制。     

Kinetic and metabolic study of benzene, toluene and m-xylene in nitrifying batch cultures

The effect of benzene, toluene, and m-xylene (BTX) compounds on the nitrifying activity of a sludge produced in steady-state nitrification was evaluated in batch cultures. Benzene and m-xylene at 10 mg C/L decreased ammonium consumption efficiency by 57% and 26%, respectively, whereas toluene did not affect the ammonium oxidation process. The consumed NH4+-N was totally oxidized to NO3- -N. There was no significant effect at 5 mg C/L of each aromatic compound. BTX (5-20mg C/L) induced a significant decrease in the values for specific rates of NH4+ -N consumption (76-99%) and NO3- -N production (45-98%). At 10 mg C/L of BTX compounds, the inhibition order on nitrate production was: benzene > m-xylene > toluene while at 20 mg C/L, the sequence changed to m-xylene > toluene > benzene for both nitrification inhibition and BTX compounds persistence. At 5 mg C/L of BTX compounds, there was no toxic effect on the sludge whereas from 10 to 50 mgC/L, bacteria did not totally recover their nitrifying activity. At a concentration of 5 mg C/L, toluene was first oxidized to benzyl alcohol, which was later oxidized to butyrate while m-xylene was oxidized to acetate and butyrate.     

Ammonium adsorption in aerobic granular sludge, activated sludge and anammox granules

The ammonium adsorption properties of aerobic granular sludge, activated sludge and anammox granules have been investigated. During operation of a pilot-scale aerobic granular sludge reactor, a positive relation between the influent ammonium concentration and the ammonium adsorbed was observed. Aerobic granular sludge exhibited much higher adsorption capacity compared to activated sludge and anammox granules. At an equilibrium ammonium concentration of 30 mg N/L, adsorption obtained with activated sludge and anammox granules was around 0.2 mg NH₄-N/g VSS, while aerobic granular sludge from lab- and pilot-scale exhibited an adsorption of 1.7 and 0.9 mg NH₄-N/g VSS, respectively. No difference in the ammonium adsorption was observed in lab-scale reactors operated at different temperatures (20 and 30 °C). In a lab-scale reactor fed with saline wastewater, we observed that the amount of ammonium adsorbed considerably decreased when the salt concentration increased. The results indicate that adsorption or better ion exchange of ammonium should be incorporated into models for nitrification/denitrification, certainly when aerobic granular sludge is used.     

MBBR工艺用于唐山某污水厂提标改造效能分析

唐山某污水厂进行一级A提标改造,采用MBBR工艺对氧化沟进行改造,在缺氧区及好氧区同时投加悬浮载体。改造后系统出水COD、BOD5、TN、氨氮、TP、SS分别为(30.5±5.2)、(3.4±0.6)、(13.0±1.4)、(1.6±1.0)、(0.42±0.05)、(7.55±1.18) mg/L,稳定达到一级A标准。污水厂全流程测定结果显示,好氧区存在稳定的同步硝化反硝化(SND)过程,对TN的去除率为8.9%,保障在不投加碳源的情况下出水TN稳定达标。小试结果表明,在10～12℃的低温环境下,悬浮载体的硝化速率为0.13 kgN/(m3·d),原水反硝化速率最大为0.039 kgN/(m3·d),悬浮载体的加入保障了系统低温下良好的处理效果。高通量测序结果表明:好氧区悬浮载体上硝化螺旋菌相对丰度为6.57%,是活性污泥的3倍,并且在好氧区悬浮载体上发现了相对丰度为1.85%的反硝化菌,为SND现象提供了微观解释。缺氧区悬浮载体上反硝化菌的相对丰度为7.72%,是活性污泥中的2.5倍。通过原池嵌入MBBR工艺,强化了系统的硝化反硝化效果。     

悬浮填料生物系统处理炼油废水试验

为了提高A／O工艺的脱氮效果，采用悬浮填料生物系统来处理炼油废水。试验结果表明，当装填30％反应器容积的悬浮填料、进水NH3-N和COD分别为54～75mg／L和420～570mg／L、水力停留时间为24h时，对NH3-N和COD的去除率分别达96％和88％以上，出水水质达到了排放标准。此外，在悬浮填料曝气池中还发生了同步硝化反硝化现象。     

改进型MBR对校园生活污水的硝化效果及影响因素

采用改进型膜生物反应器(MBR)处理低浓度校园生活污水,考察了其硝化效果及影响因素.结果表明,在进水NH_4~+-N为19.25～58.37 mg/L、无排泥的条件下,当MLSS为3 500～4 500 mg/L、温度>10 ℃、pH值为6.7～8.7、缺氧段DO<0.5 mg/L、好氧段DO为1.5～2.5 mg/L、污泥回流比为200%～300%时,系统的硝化效果最好,平均出水NH_4~+-N为1.28 mg/L,满足<地表水环境质量标准>(GB 3838-2002)的Ⅳ类标准.     

Simultaneous nitrification and p-cresol oxidation in a nitrifying sequencing batch reactor

The tolerance, kinetic behavior and oxidizing ability of a nitrifying sludge exposed to different initial concentrations of p-cresol (25-150mg/l) were evaluated in a sequencing batch reactor (SBR) fed with 200mg NH(4)(+)-N/ld. The nitrifying SBR operated up to 300mg/ld of p-cresol, achieving simultaneously the complete ammonium oxidation to nitrate and the total consumption of p-cresol and its transitory intermediates from the culture. p-Cresol induced a significant decrease in the values for specific rates of ammonium consumption, showing that the ammonium oxidation pathway was mainly inhibited. After 7 months of operation in SBR, the specific rates of NH(4)(+)-N oxidation, NO(3)(-)-N formation, and total organic carbon consumption were 0.6g NH(4)(+)-N/g microbial protein-Nh, 0.3g NO(3)(-)-N/g microbial protein-Nh, and 0.24g total organic carbon/g microbial protein h, respectively. The microbial growth rate was always low (maximum value of 12.2+/-0.4mg protein-N/ld) and settleability of the sludge was good with sludge volume index values lower than 21ml/g. The oxidation of p-cresol and its intermediates was carried out faster throughout the cycles and nitrification inhibition decreased with the number of cycles.     

Simultaneous heterotrophic and sulfur-oxidizing autotrophic denitrification process for drinking water treatment: control of sulfate production

A long-term performance of a packed-bed bioreactor containing sulfur and limestone was evaluated for the denitrification of drinking water. Autotrophic denitrification rate was limited by the slow dissolution rate of sulfur and limestone. Dissolution of limestone for alkalinity supplementation increased hardness due to release of Ca²⁺. Sulfate production is the main disadvantage of the sulfur autotrophic denitrification process. The effluent sulfate concentration was reduced to values below drinking water guidelines by stimulating the simultaneous heterotrophic and autotrophic denitrification with methanol supplementation. Complete removal of 75 mg/L NO₃-N with effluent sulfate concentration of around 225 mg/L was achieved when methanol was supplemented at methanol/NO₃-N ratio of 1.67 (mg/mg), which was much lower than the theoretical value of 2.47 for heterotrophic denitrification. Batch studies showed that sulfur-based autotrophic NO₂-N reduction rate was around three times lower than the reduction rate of NO₃-N, which led to NO₂-N accumulation at high loadings.     

浙江某工业废水处理厂升级改造运行效果解析

浙江某工业废水处理厂升级改造,采用AAO—MBBR复合生物膜工艺,在未新增建设用地和扩建池容的基础上,日处理量由3×10⁴m³/d提高至6×10⁴m³/d。改造后实际运行出水COD、TP、NH₃-N和TN浓度分别为(37.7±6.61)、(0.09±0.03)、(0.25±0.14)和(5.87±1.54)mg/L,出水水质稳定达到一级A标准。实际监测表明,在好氧MBBR区存在TN去除现象,约占TN总去除量的10.36%。系统内的优势硝化菌属为硝化螺旋菌属Nitrospira,其在悬浮载体生物膜和活性污泥中的相对丰度分别为8.98%和0.92%,悬浮载体的投加使硝化细菌得到有效富集;反硝化菌在生物膜中的占比为7.94%,为悬浮载体同步硝化反硝化(SND)效果的发生提供了微观保证,提高了TN去除率。     

矿化垃圾填料对污水中氮磷去除能力的动力学研究

矿化垃圾填料具备良好的粒径级配,表面为不规则的多面体,Fe、Al和Ca成分含量高,具备成为优良磷库的条件。培养实验结果可采用Langmuir吸附等温线模拟,计算所得矿化垃圾磷的饱和吸附量为2 914 mg.kg-1。矿化垃圾吸附磷的饱和吸附量和吸附速率均为粘土的3倍多,磷的解析率仅约为30%。硝化培养实验前24 h内,矿化垃圾中氨氮的浓度从129 mg N.kg-1下降到83.0 mgN.kg-1;硝酸盐氮含量相应地从137 mg N.kg-1上升到170 mg N.kg-1。而同期内粘土中氨氮的浓度下降和硝酸盐氮含量的上升幅度分别为矿化垃圾的1/2和1/6。反硝化培养过程中,矿化垃圾中硝酸盐氮零级动力学降解速率常数K值为粘土7.5倍。     

Enhanced ammonia nitrogen removal using consistent biological regeneration and ammonium exchange of zeolite in modified SBR process

The modified zeo-SBR is recommended for a new nitrogen removal process that has a special function of consistent ammonium exchange and bioregeneration of zeolite-floc. Three sets of sequencing batch reactors, control, zeo-SBR, and modified zeo-SBR were tested to assess nitrogen removal efficiency. The control reactor consisted of anoxic-fill, aeration-mixing, settling, and decanting/idle phases, meaning that nitrogen removal efficiency was dependent on the decanting volume in a cycle. The zeo-SBR reactor was operated in the same way as the control reactor, except for daily addition of powdered zeolite in the SBR reactor. The operating order sequences in the zeo-SBR were changed in the modified zeo-SBR. Anoxic-fill phase was followed by aeration-mixing phase in the zeo-SBR, while aeration-mixing phase was followed by anoxic-fill phase in the modified zeo-SBR to carry NH4(+)-N over to the next operational cycle and to reduce total nitrogen concentration in the effluent. In the modified zeo-SBR, nitrification and biological regeneration occurred during the initial aeration-mixing phase, while denitrification and ammonium adsorption occurred in the following anoxic-fill phase. The changed operational sequence in the modified zeo-SBR to adapt the ammonium adsorption and biological regeneration of the zeolite-floc could enhance nitrogen removal efficiency. As a result of the continuous operation, the nitrogen removal efficiencies of the control and zeo-SBR were in 68.5-70.9%, based on the 33% of decanting volume for a cycle. The zeo-SBR showed a consistent ammonium exchange and bio-regeneration in the anoxic-fill and aeration-mixing phases, respectively. Meanwhile, the effluent total nitrogen of the modified zeo-SBR showed 50-60 mg N/L through ammonium adsorption of the zeolite-floc when the influent ammonium concentration was 315 mg N/L, indicating the T-N removal efficiency was enhanced over 10% in the same HRT and SRT conditions as those of control and zeo-SBR reactors. The ammonium adsorption capacity was found to be 6-7 mg NH4(+)-N/g FSS that is equivalent to 40 mg NH4(+)-N/L of ammonium nitrogen removal.