WorldWideScience

Sample records for biological nitrogen removal

  1. Optimizing processes for biological nitrogen removal in Nakivubo wetland, Uganda

    OpenAIRE

    Kyambadde, Joseph

    2005-01-01

    The ability of Nakivubo wetland (which has performed tertiary water treatment for Kampala city for the past 40 years) to respond to pollution and to protect the water quality of Inner Murchison Bay of Lake Victoria was investigated. The aim of this study was to assess the capacity of Nakivubo wetland to remove nitrogen from the wastewater after its recent encroachment and modification, in order to optimize biological nitrogen removal processes using constructed wetland technology. Field studi...

  2. Thermophilic biological nitrogen removal in industrial wastewater treatment.

    OpenAIRE

    Lopez-Vazquez, CM; Kubare, M.; Saroj, DP; Chikamba, C; Schwarz, J.; Daims, H.; Brdjanovic, D.

    2013-01-01

    Nitrification is an integral part of biological nitrogen removal processes and usually the limiting step in wastewater treatment systems. Since nitrification is often considered not feasible at temperatures higher than 40 °C, warm industrial effluents (with operating temperatures higher than 40 °C) need to be cooled down prior to biological treatment, which increases the energy and operating costs of the plants for cooling purposes. This study describes the occurrence of thermophilic biologic...

  3. Biological removal of nitrogen from waste water

    Energy Technology Data Exchange (ETDEWEB)

    Dombrowski, T.; Lompe, D.; Wiesmann, U.

    1989-02-01

    The biological treatment of waste water with both a high organic (2500 mg/l DOC) and high ammonia concentration (600 mg/l NH/sub 4//sup +/-N) was investigated. The first step consists of a two step anaerobic cascade of fixed bed loop reactors with polyurethan foam particles as support material for bacterica. The aerobic treatment occurs in two aerated stirred tanks with sedimentation tanks and two separate sludge recycle systems each for heterotrophic and autotrophic biomass resulting in a degradation of organic compounds (first tank) and nitrification (second tank). Finally the nitrate is reduced by biological denitrification. By optimization the total hydraulic retention time could be reduced to 7 hr. Nitrification is the most sensitive step and can be on-line controlled by measurement of oxygen consumption.

  4. Biological phosphorus and nitrogen removal in a single sludge system

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Hans

    1996-05-01

    The primary aim of this thesis was to investigate the process stability of a single sludge activated system designed for the combined operation of enhanced biological phosphorus removal (EBPR) and nitrogen removal. A pilot plant at the Sjoelunda wastewater treatment plant in Malmoe, Sweden, has formed the basis for the investigation. The pilot plant study showed that the concentration of total phosphorus on average was low in the effluent, below 0.5 mg P/l. Simultaneously with the highest concentrations of phosphorus in the effluent, the lowest COD/P ratios in the effluent were recorded. A recurrent pattern of high concentrations of phosphorus was observed every year in July, which is the industrial holiday month in Sweden. Other instances of increased phosphorus concentrations in the secondary effluent illustrate the effect of prolonged periods of rain. Increasing flow rates due to rain lead to a dilution and a change in the composition of the COD in the influent wastewater. The COD/P and VFA/P ratios decrease with decreasing concentrations of COD. It was also shown that high removal ratios of both nitrogen and phosphorus during long periods are possible. The nitrogen removal was stable during the whole investigated period, whereas the phosphorus removal was unstable during prolonged periods with low concentrations of COD in the influent water. The combined biological phosphorus and nitrogen removal process implies that during these periods the risk of recirculating nitrate to the anaerobic reactor increases. Such a recirculation both stabilizes the nitrogen removal and withdraws some of the readily degradable organic material from the bio-P bacteria. The main conclusion of this study is that a phosphorus limited EBPR process can cope with the day to day variations, but occasionally, measures have to be taken if the demands for phosphorus removal are stringent. 49 refs, 8 figs, 1 tab

  5. Benchmarking Combined Biological Phosphorus and Nitrogen Removal Wastewater Treatment Processes

    DEFF Research Database (Denmark)

    Gernaey, Krist; Jørgensen, Sten Bay

    2004-01-01

    This paper describes the implementation of a simulation benchmark for studying the influence of control strategy implementations on combined nitrogen and phosphorus removal processes in a biological wastewater treatment plant. The presented simulation benchmark plant and its performance criteria...... conditions respectively, the definition of performance indexes that include the phosphorus removal processes, and the selection of a suitable operating point for the plant. Two control loops were implemented: one for dissolved oxygen control using the oxygen transfer coefficient K(L)a as manipulated variable...... are to a large extent based on the already existing nitrogen removal simulation benchmark. The paper illustrates and motivates the selection of the treatment plant lay-out, the selection of the biological process model, the development of realistic influent disturbance scenarios for dry, rain and storm weather...

  6. Gamma ray irradiation for sludge solubilization and biological nitrogen removal

    International Nuclear Information System (INIS)

    This study was conducted to investigate the effects of gamma ray irradiation on the solubilization of waste sewage sludge. The recovery of an organic carbon source from sewage sludge by gamma ray irradiation was also studied. The gamma ray irradiation showed effective sludge solubilization efficiencies. Both soluble chemical oxygen demand (SCOD) and biochemical oxygen demand (BOD5) increased by gamma ray irradiation. The feasibility of the solubilized sludge carbon source for a biological nitrogen removal was also investigated. A modified continuous bioreactor (MLE process) for a denitrification was operated for 20 days by using synthetic wastewater. It can be concluded that the gamma ray irradiation was useful for the solubilization of sludge and the recovery of carbon source from the waste sewage sludge for biological nitrogen removal. - Research highlights: → This study was conducted to investigate the effects of gamma ray irradiation on the solubilization of waste sewagesludge. → The recovery of an organic carbon source from sewage sludge by gamma ray irradiation was also studied. → It can be concluded that the gamma ray irradiation was useful for the solubilization of sludge and the recovery of carbon source from the waste sewage sludge for biological nitrogen removal.

  7. Characteristics and transformations of dissolved organic nitrogen in municipal biological nitrogen removal wastewater treatment plants

    Science.gov (United States)

    Huo, Shouliang; Xi, Beidou; Yu, Honglei; Qin, Yanwen; Zan, Fengyu; Zhang, Jingtian

    2013-12-01

    Dissolved organic nitrogen (DON) represents most of the dissolved nitrogen in the effluent of biological nitrogen removal (BNR) wastewater treatment plants (WWTPs). The characteristics of wastewater-derived DON in two different WWTPs were investigated by several different methods. The major removals of DON and biodegradable dissolved organic nitrogen (BDON) along the treatment train were observed in the anaerobic process. Dissolved combined amino acids (DCAA) and dissolved free amino acids (DFAA) in the effluent accounted approximately for less than 4% and 1% of the effluent DON, respectively. Approximately half of wastewater-derived DON was capable of passing through a 1 kDa ultrafilter, and low MW DON cannot effectively be removed by BNR processes. More than 80% of effluent DON was composed of hydrophilic compounds, which stimulate algal growth. The study provided important information for future upgrading of WWTPs or the selection of DON removal systems to meet more demanding nitrogen discharge limits.

  8. Effect of nitrogen on phosphate reduction in biological phosphorus removal from wastewater

    OpenAIRE

    Vabolienė, Giedrė; Matuzevičius, Algimantas B.; Valentukevičienė, Marina

    2007-01-01

    Conventional schemes of biological nitrogen removal can be combined with phosphorus removal schemes. One of the common technology schemes for biological nitrogen removal is the aeration zone and the anoxic zone in one tank. The nitrification and denitrification are carried out during the aeration switching on and off. The anaerobic zone is equipped behind the nitrification/denitrification tank for biological phosphorus removal. Exchange of the anaerobic and aerobic conditions is necessary for...

  9. Biological nitrogen removal using a submerged membrane bioreactor system

    International Nuclear Information System (INIS)

    A pilot-scale study was conducted using ZenoGem hollow-fiber microfiltration membrane bioreactor system to investigate the performance of membrane bioreactor process to remove nitrogen from primary effluent at a municipal wastewater treatment plant. Different operating conditions were examined by varying hydraulic retention time (HRT) and sludge retention time (SRT) between 5-8 h and 20-50 days, respectively. In addition, a series of laboratory batch tests were performed to measure the biodegradation kinetic and stoichiometric parameters under the conditions consistent with the pilot testing. The results showed that the process achieved removal efficiencies of 80-98% for COD, 93%-99% for BOD5, and 70-93% for nitrogen. The efficiency and kinetics of COD and nitrogen removal would change greatly from one operating condition to another. However, the measured kinetic parameters still fell within the typical range of those reported in the literature using Activated Sludge Models (ASM)

  10. Effect of Cu(II) shock loads on shortcut biological nitrogen removal in a hybrid biofilm nitrogen removal reactor.

    Science.gov (United States)

    Yin, Jun; Xu, Hengjuan; Shen, Dongsheng; Wang, Kun; Lin, Ying

    2015-06-01

    The effect of Cu(II) shock loads on shortcut biological nitrogen removal during a continuous-flow anoxic/aerobic process was investigated using a hybrid biofilm nitrogen removal reactor. The results demonstrated that [Formula: see text]-N removal was not affected by any Cu(II) shock loads, but TN removal was inhibited by Cu(II) of shock loads of 2 and 5 mg/L, and the performance could not be recovered at 5 mg/L. Furthermore, the TN removal pathway also changed in response to Cu(II) concentrations of 2 and 5 mg/L. Denitrification is more sensitive to Cu(II) shock in SBNR processes. Examination of amoA communities using quantitative PCR showed that the abundance of AOB in the aerobic tank decreased after Cu(II) shock with 5 mg/L, which supported the observed changes in [Formula: see text]-N removal efficiency. The abundance of denitrification genes declined obviously at Cu(II) concentrations of 2 and 5 mg/L, which explained the decreased TN removal efficiency at those concentrations. PMID:25833010

  11. Effective Biological Nitrogen Removal Treatment Processes for Domestic Wastewaters with Low C/N Ratios: A Review

    DEFF Research Database (Denmark)

    Sun, Sheng-Peng; Pellicer i Nàcher, Carles; Merkey, Brian;

    2010-01-01

    Discharge of nitrogenous components to water bodies can cause eutrophication, deterioration of water quality, toxicity to aquatic life, and pose a potential hazard to human and animal health. Biological nitrogen removal can remove nitrogenous components via conversion to harmless nitrogen gas...... with high efficiency and relative low costs. However, the removal of nitrogen from domestic wastewater with a low carbon/nitrogen (C/N) ratio can often be limited in municipal wastewater plants (WWTPs) because organic carbon is a limiting factor for denitrification. The present work reviews innovative......-effective nitrogen removal from low C/N ratio domestic wastewater can be obtained in the near future....

  12. Simultaneous nitrification and denitrification in step feeding biological nitrogen removal process

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The simultaneous nitrification and denitrification in step-feeding biological nitrogen removal process were investigated under different influent substrate concentrations and aeration flow rates.Biological occurrence of simultaneous nitrification and denitrifieation was verified in the aspect of nitrogen mass balance and alkalinity.The experimental results also showed that there was a distinct linear relationship between simultaneous nitrification and denitrification and DO concentration under the conditions of low and high aeration flow rate.In each experimental run the floe sizes of activated sludge were also measured and the results showed that simultaneous nitrification and denitrification could occur with very small size of floc.

  13. BIOLOGICAL AERATED FILTERS (BAFs FOR CARBON AND NITROGEN REMOVAL: A REVIEW

    Directory of Open Access Journals (Sweden)

    ELSHAFIE AHMED

    2012-08-01

    Full Text Available Biological aerated filters (BAFs are an emerging wastewater treatment technology designed for a wide range of municipal and industrial applications. This review paper presents and discusses of the influence C/N ratio, nitrification and denitrification principle, effect of pH, DO and alkalinity on the nitrification and denitrification systems, organic and hydraulic loading of BAF reactor, etc. Results from upflow and downflow biofilter pilot at different condition, with nitrification and denitrification are reviewed. Under the optimal conditions, significant amount of COD, ammonia-nitrogen and total nitrogen were removed. Removal rates based on reactor volume for different carbon-aceous COD and ammonia loading rate are reported. The BAF system for the nitrification and denitrification processes for carbon and nitrogen removal from the wastewater need to be evaluated and applied properly to protect of our environment and resources.

  14. Monitoring of Biological Nitrogen Removal in Tannery Wastewater Using a Sequencing Batch Reactor

    Directory of Open Access Journals (Sweden)

    Carrasquero-Ferrer Sedolfo José

    2014-04-01

    Full Text Available The objective of this research was to relate the biological nitrogen removal in tannery wastewater with profiles of pH, alkalinity and redox potential (ORP using a sequencing batch reactor (SBR with a working volume of 2 L. The reactor worked under two operational sequences: anoxic-aerobic-anoxic (Ax/Ae/Ax and aerobic-anoxic (Ae/Ax, which were combined with two cell retention times (CRT (15 and 25 days, with an operation cycle time (OCT of 11 hours. The profiles were performed by measuring each 15 minutes the following parameters: pH, dissolved oxygen (DO, ORP, and each hour the parameters: total alkalinity, total chemical oxygen demand (DQOT, soluble chemical oxygen demand (DQOS, total Kjeldahl nitrogen (TKN, nitrite (NO2-, nitrate (NO3- and ammonia nitrogen (N-NH4+. Alkalinity and ORP profile were excellent indicators of the processes of biological nitrogen removal. However, pH could not be used as a control parameter, due to the buffering capacity of tannery wastewater. Finally, this research work showed that alkalinity and ORP values can be used as on-line control parameters to monitor the evolution of the nitrogen removal in tannery wastewater (nitrification and denitrification processes.

  15. Biological nitrogen and phenol removal from saline industrial wastewater by submerged fixed-film reactor

    International Nuclear Information System (INIS)

    In this study a biological nitrogen removal process using a submerged fixed-film reactor was applied to treat industrial wastewater with phenol (1 g/l), a high nitrogen concentration (0.4 g N/l) and high salinity (30 g/l). The process consisted of a pre-denitrification system with a down-flow-up-flow biofilter (two columns, each with an effective volume of 21 l) packed with clayey schists from recycled construction material. The efficiency of the system for reducing COD, phenol concentration and total nitrogen was tested under different running conditions such as influent flow (10, 12 and 15 l/d), air loading (6.8 and 13.6 m3/m2 h) and effluent recirculation (300%, 400%, and 600%). The system demonstrated a high capacity for reducing COD concentration (95.75 ± 0.72%), independently of running conditions. The aerobic column eliminated most of the phenol in the influent. Nitrogen removal took place mainly in the anoxic column, and was conditioned by the air loading in the aerated column, owing to the dependence of nitrification on the supply of oxygen. However, this process was not able to achieve a nitrogen oxidation superior to 63%, in spite of a sufficient supply of oxygen and the diluting effect of high recirculation (600%) on the phenol concentration in the influent. In spite of the limitations observed in the process of nitrification, results for the removal of total nitrogen were as high as 83%, owing to a combination of different processes for nitrogen removal

  16. Enhancing combined biological nitrogen and phosphorus removal from wastewater by applying mechanically disintegrated excess sludge.

    Science.gov (United States)

    Zubrowska-Sudol, Monika; Walczak, Justyna

    2015-06-01

    The goal of the study was to evaluate the possibility of applying disintegrated excess sludge as a source of organic carbon to enhance biological nitrogen and phosphorus removal. The experiment, performed in a sequencing batch reactor, consisted of two two-month series, without and with applying mechanically disintegrated excess sludge, respectively. The effects on carbon, nitrogen and phosphorus removal were observed. It was shown that the method allows enhancement of combined nitrogen and phosphorus removal. After using disintegrated sludge, denitrification effectiveness increased from 49.2 ± 6.8% to 76.2 ± 2.3%, which resulted in a decline in the NOx-N concentration in the effluent from the SBR by an average of 21.4 mg NOx-N/L. Effectiveness of biological phosphorus removal increased from 28.1 ± 11.3% to 96.2 ± 2.5%, thus resulting in a drop in the [Formula: see text] concentration in the effluent by, on average, 6.05 mg PO4(3-)-P/L. The application of disintegrated sludge did not deteriorate effluent quality in terms of COD and NH4(+)-N. The concentration of NH4(+)-N in both series averaged 0.16 ± 0.11 mg NH4(+)-N/L, and the concentration of COD was 15.36 ± 3.54 mg O2/L. PMID:25776916

  17. Population dynamics in wastewater treatment plants with enhanced biological phosphorus removal operated with and without nitrogen removal

    DEFF Research Database (Denmark)

    Lee, N.; Jansen, J.l.C.; Aspegren, H.;

    2002-01-01

    The population dynamics of activated sludge in a pilot plant with two activated sludge systems, both designed for enhanced biological phosphorus removal (EBPR), but one of them with (BNP) and the other without (BP) nitrogen removal, was monitored during a period of 2.5 years. The influent water...... to the pilot plant was periodically manipulated by external addition of phosphorus (P), acetate and glucose, respectively. The population dynamics and the in situ physiology were monitored by quantitative fluorescence in situ hybridization (FISH) and microautoradiography. Significant P removal was observed...... in both systems throughout the whole period, with significant increases of the P removal when substrates were dosed. The activated sludge in both systems contained large amounts of dense clusters of gram-negative, methylene-blue staining coccoid rods during the whole period. A large part of the clusters...

  18. Comparison Between Biological Treatment and Chemical Precipitation for Nitrogen Removal from Old Landfill Leachate

    Directory of Open Access Journals (Sweden)

    Long Tengrui

    2007-01-01

    Full Text Available The study reports the results of a laboratory scale investigation aimed at evaluating the effectiveness of mature municipal landfill leachate treatment by a biological stage (used SBBR as a biological treatment and Chemical precipitation (Used MAP precipitation (magnesium ammonium phosphate to study the nitrogen removal capabilities for treatment of sanitary landfill leachate containing high ammonia concentration, and the comparison between them. The monitored sample taken from the Chang Sheng bridge landfill site in Chongqing city-China, has its concentrations of COD, BOD5, and NH3-N about 1650, 75 and 1100 mg/l respectively. The results from SBBR showed that after two months long period of domestication and one month period of stability, the ammonia nitrogen removal efficiency reached to 99% in the SBBR reactor, at nitrogen loading rate 0.51 kg TN/m3 per day and HRT was 9 hours, met to Chinese standards for discharge. The results of the MAP precipitation was technically effective to remove the high NH3-N strength of over 1100 mg/l from the raw leachate at molar ratio of Mg2+: NH4+: PO4-3 of 1:1:1, they demonstrated a very satisfactory removal of ammonia; an initial NH3+-N concentration of 1100 mg/l contained in the raw leachate was quickly reduced to 28 mg/l within 15 min, while the pH producing a maximum removal of ammonia was 9.0. The percent removal of ammonia after treatment by MAP was 97.5%.

  19. Achieving and maintaining biological nitrogen removal via nitrite under normal conditions

    Institute of Scientific and Technical Information of China (English)

    CUI You-wei; PENG Yong-zhen; GAN Xiang-qing; YE Liu; WANG Ya-yi

    2005-01-01

    The principal aim of this paper is to develop an approach to realize stable biological nitrogen removal via nitrite under normal conditions. Validation of the new method was established on laboratory-scale experiments applying the sequencing batch reactor(SBR)activated sludge process to domestic wastewater with low C/N ratio. The addition of sodium chloride(NaCl) to influent was established to achieve nitrite build-up. The high nitrite accumulation, depending on the salinity in influent and the application duration of salt, was obtained in SBRs treating saline wastewater. The maintenance results indicated that the real-time SBRs can maintain stable nitrite accumulation, but conversion from shorter nitrification-denitrification to full nitrification-denitrification was observed after some operation cycles in the other SBR with fixed-time control. The presented method is valuable to offer a solution to realize and to maintain nitrogen removal via nitrite under normal conditions.

  20. Biological Nitrogen Removal through Nitritation Coupled with Thiosulfate-Driven Denitritation.

    Science.gov (United States)

    Qian, Jin; Zhou, Junmei; Zhang, Zhen; Liu, Rulong; Wang, Qilin

    2016-01-01

    A novel biological nitrogen removal system based on nitritation coupled with thiosulfate-driven denitritation (Nitritation-TDD) was developed to achieve a high nitrogen removal rate and low sludge production. A nitritation sequential batch reactor (nitritation SBR) and an anoxic up-flow sludge bed (AnUSB) reactor were applied for effective nitritation and denitritation, respectively. Above 75% nitrite was accumulated in the nitritation SBR with an influent ammonia loading rate of 0.43 kg N/d/m(3). During Nitritation-TDD operation, particle sizes (d50) of the sludge decreased from 406 to 225 um in nitritation SBR and from 327-183 um in AnUSB reactor. Pyrosequencing tests revealed that ammonium-oxidizing bacteria (AOB) population was stabilized at approximately 7.0% (calculated as population of AOB-related genus divided by the total microbial population) in the nitritation SBR. In contrast, nitrite-oxidizing bacteria (NOB) population decreased from 6.5-0.6% over the same time, indicating the effective nitrite accumulation in the nitritation SBR. Thiobacillus, accounting for 34.2% in the AnUSB reactor, was mainly responsible for nitrogen removal via autotrophic denitritation, using an external source of thiosulfate as electron donor. Also, it was found that free nitrous acid could directly affect the denitritation activity. PMID:27272192

  1. Monitoring of Biological Nitrogen Removal in Tannery Wastewater Using a Sequencing Batch Reactor

    OpenAIRE

    Carrasquero-Ferrer Sedolfo José; Pire-Sierra María Carolina; Rincón-Lizardo Nancy Coromoto; Díaz-Montiel Altamira Rosa

    2014-01-01

    The objective of this research was to relate the biological nitrogen removal in tannery wastewater with profiles of pH, alkalinity and redox potential (ORP) using a sequencing batch reactor (SBR) with a working volume of 2 L. The reactor worked under two operational sequences: anoxic-aerobic-anoxic (Ax/Ae/Ax) and aerobic-anoxic (Ae/Ax), which were combined with two cell retention times (CRT) (15 and 25 days), with an operation cycle time (OCT) of 11 hours. The profiles were performed by measu...

  2. Simultaneous nitrogen and phosphorus removal in the sulfur cycle-associated Enhanced Biological Phosphorus Removal (EBPR) process.

    Science.gov (United States)

    Wu, Di; Ekama, George A; Wang, Hai-Guang; Wei, Li; Lu, Hui; Chui, Ho-Kwong; Liu, Wen-Tso; Brdjanovic, Damir; van Loosdrecht, Mark C M; Chen, Guang-Hao

    2014-02-01

    Hong Kong has practiced seawater toilet flushing since 1958, saving 750,000 m(3) of freshwater every day. A high sulfate-to-COD ratio (>1.25 mg SO4(2-)/mg COD) in the saline sewage resulting from this practice has enabled us to develop the Sulfate reduction, Autotrophic denitrification and Nitrification Integrated (SANI(®)) process with minimal sludge production and oxygen demand. Recently, the SANI(®) process has been expanded to include Enhanced Biological Phosphorus Removal (EBPR) in an alternating anaerobic/limited-oxygen (LOS-EBPR) aerobic sequencing batch reactor (SBR). This paper presents further development - an anaerobic/anoxic denitrifying sulfur cycle-associated EBPR, named as DS-EBPR, bioprocess in an alternating anaerobic/anoxic SBR for simultaneous removal of organics, nitrogen and phosphorus. The 211 day SBR operation confirmed the sulfur cycle-associated biological phosphorus uptake utilizing nitrate as electron acceptor. This new bioprocess cannot only reduce operation time but also enhance volumetric loading of SBR compared with the LOS-EBPR. The DS-EBPR process performed well at high temperatures of 30 °C and a high salinity of 20% seawater. A synergistic relationship may exist between sulfur cycle and biological phosphorus removal as the optimal ratio of P-release to SO4(2-)-reduction is close to 1.0 mg P/mg S. There were no conventional PAOs in the sludge. PMID:24342048

  3. Advances in wastewater nitrogen removal by biological processes: state of the art review

    Directory of Open Access Journals (Sweden)

    Andrea G. Capodaglio

    2016-04-01

    Full Text Available The paper summarizes the state-of-the-art of the most recent advances in biological nitrogen removal, including process design criteria and technological innovations. With reference to the Modified Ludzck Ettinger (MLE process (pre-denitrification and nitrification in the activated sludge process, the most common nitrogen removal process used nowadays, a new design equation for the denitrification reactor based on specific denitrification rate (SDNR has been proposed. In addition, factors influencing SDNR (DO in the anoxic reactor; hydrodynamic behavior are analyzed, and technological solutions are proposed. Concerning technological advances, the paper presents a summary of various “deammonification” processes, better known by their patent names like ANAMMOX®, DEMON®, CANON®, ANITA® and others. These processes have already found applications in the treatment of high-strength wastewater such as digested sludge liquor and landfill leachate. Among other emerging denitrification technologies, consideration is given to the Membrane Biofilm Reactors (MBfRs that can be operated both in oxidation and reduction mode.

  4. Biological nitrogen removal with enhanced phosphate uptake in (AO)2SBR using single sludge system

    Institute of Scientific and Technical Information of China (English)

    JIANG Yi-feng; WANG Lin; WANG Bao-zhen; HE Sheng-bing; LUI Shuo

    2004-01-01

    Simultaneous biological phosphorus and nitrogen removal with enhanced anoxic phosphate uptake via nitrite was investigated in an anaerobic-aerobic-anoxic-aerobic sequencing batch reactor((AO)2 SBR). The system showed stable phosphorus and nitrogen removal performance, and average removals for COD, TN and TP were 90%, 91% and 96%, respectively. The conditions of pH 7.5-8.0 and temperature 32℃ were found detrimental to nitrite oxidation bacteria but favorable to ammonia oxidizers, and the corresponding specific oxygen uptake rates(SOUR) for phase 1 and 2 of nitrification process were 0.7 and 15 mgO2/(gVSS·h) in respect, which led to the nitrite accumulation in aerobic phase of(AO)2 SBR. Respiratory tests showed that 40 mgNO2-N/L did not deteriorate the sludge activity drastically, and it implied that exposure of sludge to nitrite periodically enabled the biomass to have more tolerance capacity to resist the restraining effects from nitrite. In addition, batch tests were carried out and verified that denitrifying phosphorus accumulation organisms(DPAOs) could be enriched in a single sludge system coexisting with nitrifiers by introducing an anoxic phase in an anaerobic-aerobic SBR, and the ratio of the anoxic phosphate uptake capacity to aerobic phosphate uptake capacity was 45%. It was also found that nitrite(up to 20 mgNO2-N/L) was not inhibitory to anoxic phosphate uptake and could serve as an electron acceptor like nitrate, but presented poorer efficiency compared with nitrate.

  5. Modeling Nitrous Oxide Production during Biological Nitrogen Removal via Nitrification and Denitrification: Extensions to the General ASM Models

    DEFF Research Database (Denmark)

    Ni, Bing-Jie; Ruscalleda, Maël; Pellicer i Nàcher, Carles;

    2011-01-01

    Nitrous oxide (N2O) can be formed during biological nitrogen (N) removal processes. In this work, a mathematical model is developed that describes N2O production and consumption during activated sludge nitrification and denitrification. The well-known ASM process models are extended to capture N2...

  6. BIOLOGICAL NITROGEN REMOVAL FROM WASTEWATER BY DENITRIFICATION OF MIX-CULTURING FUNGI AND BACTERIA

    Institute of Scientific and Technical Information of China (English)

    TAKAYA; Naoki; SHOUN; Hirofumi

    2006-01-01

    Denitrificationis a biological processin which nitrateand/or nitrite is reduced to gaseous nitrogen,dinitrogen(N2)or nitrous oxide(N2O)while carbon dioxide is thesecond gaseous product of the process.This is one of themain mechanisms of the global nitrogen cycle,and playsanimportant role as the reverse reaction of nitrogen fixa-tion in maintaining global environmental homeostasis[1].Denitrification has beenlongthought to be a unique char-acteristic of prokaryotes[2,3].Anumber of bacteria(suchasPseudomonas s...

  7. Mathematical Modeling and Evaluation of Ifas Wastewater Treatment Processes for Biological Nitrogen and Phosphorus Removal

    OpenAIRE

    Sriwiriyarat, Tongchai

    2002-01-01

    The hybrid activated sludge-biofilm system called Integrated Fixed Film Activated Sludge (IFAS) has recently become popular for enhanced nitrification and denitrification in aerobic zones because it is an alternative to increasing the volume of treatment plant units to accomplish year round nitrification and nitrogen removal. Biomass is retained on the fixed-film media and remains in the aerobic reactor, thus increasing the effective mean cell resident time (MCRT) of the biomass and providin...

  8. Biological hydrogen production: Simultaneous saccharification and fermentation with nitrogen and phosphorus removal from wastewater effluent

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, Steve; Dixon, Melissa [U.S. Army Edgewood Chemical Biological Center, 5183 Blackhawk Road Building E3160, Aberdeen Proving Ground, MD 21010-5424 (United States)

    2010-09-15

    A simple anaerobic biodegradation process using wastewater treatment plant (WWTP) effluent, shredded paper, and a purge of nitrogen gas was used to produce hydrogen and simultaneously capture nitrogen and phosphorus. Two reactor configurations, a sequencing batch reactor (SBR) and a classic batch reactor (CBR) were tested as simultaneous saccharification and fermentation reactors (enzymatic hydrolysis and fermentation in one tank). The CBR demonstrated greater stability of hydrogen production and simplicity of operation, while the SBR provided better nitrogen and phosphorus removal efficiencies. Nuclear magnetic resonance analyses showed acetic acid to be the main product from both reactors. Optimal CBR conditions were found to be pH 5, 4 g/L loading, 0.45 ml/g Accellerase 1500, and 38 C. Experiments with an argon purge in place of nitrogen and with ammonium chloride spiking suggested that hydrogenase and nitrogenase enzymes contributed similarly to hydrogen production in the cultures. Analysis of a single fermentation showed that hydrogen production occurred relatively early in the course of TOC removal, and that follow-on treatments might extract more energy from the products. (author)

  9. The use of mathematical modeling and pilot plant testing to develop a new biological phosphorus and nitrogen removal process

    Energy Technology Data Exchange (ETDEWEB)

    Nolasco, D.A.; Daigger, G.T.; Stafford, D.R.; Kaupp, D.M.; Stephenson, J.P.

    1998-09-01

    A mechanistic mathematical model for carbon oxidation, nitrogen removal, and enhanced biological phosphorus removal was used to develop the Step Bio-P process, a new biological phosphorus and nitrogen removal process with a step-feed configuration. A 9,000-L pilot plant with diurnally varying influent process loading rates was operated to verify the model results and to optimize the Step Bio-P process for application at the lethbridge, Alberta, Canada, wastewater treatment plant. The pilot plant was operated for 10 months. An automatic on-line data acquisition system with multiple sampling and metering points for dissolved oxygen, mixed liquor suspended solids, ammonia-nitrogen, nitrate-nitrogen, ortho-phosphate, and flow rates was used. A sampling program to obtain off-line data was carried out to verify the information from the on-line system and monitor additional parameters. The on-line and off-line data were used to recalibrate the model, which was used as an experimental design and process optimization tool.

  10. Optimization of electrochemical reaction for nitrogen removal from biological secondary-treated milking centre wastewater.

    Science.gov (United States)

    Won, Seung-Gun; Jeon, Dae-Yong; Rahman, Md Mukhlesur; Kwag, Jung-Hoon; Ra, Chang-Six

    2016-01-01

    In order to remove the residual nitrogen from the secondary-treated milking centre wastewater, the electrochemical reaction including NH4-N oxidation and NOx-N reduction has been known as a relatively simple technique. Through the present study, the electrochemical reactor using the Ti-coated IrO2 anode and stainless steel cathode was optimized for practical use on farm. The key operational parameters [electrode area (EA) (cm(2)/L), current density (CD) (A/cm(2)), electrolyte concentration (EC) (mg/L as NaCl), and reaction time (RT) (min)] were selected and their effects were evaluated using response surface methodology for the responses of nitrogen and colour removal efficiencies, and power consumption. The experimental design was followed for the central composite design as a fractional factorial design. As a result of the analysis of variance, the p-values of the second-order polynomial models for three responses were significantly fit to the empirical values. The nitrogen removal was significantly influenced by CD, EC, and RT (p NaCl; RT, 240 min] was revealed as an optimal operational condition. The investigation on cathodic reduction of NOx-N may be required with respect to nitrite and nitrate separately as a future work. PMID:26582173

  11. Biological removal of phosphorus and nitrogen from wastewater : new insights from metagenomic and metatranscriptomic approaches

    OpenAIRE

    Mao, Yanping; 毛艷萍

    2014-01-01

    The study was conducted to reveal the insights of microbial diversity, functional profile and gene expression of microorganisms responsible for enhanced biological phosphorus removal (EBPR) and hydrogen-oxidizing autotrophic denitrification mainly by using metagenomic and metatranscriptomic analysis based on high-throughput sequencing. Two sequencing batch reactors (SBRs) were operated to remove phosphorus (15 mg/L) from synthetic wastewater. The integrated metagenomic and metatranscripto...

  12. Long-term population dynamics and in situ physiology in activated sludge systems with enhanced biological phosphorus removal operated with and without nitrogen removal

    DEFF Research Database (Denmark)

    Lee, N.; Nielsen, P.H.; Aspegren, H.; Henze, Mogens; Schleifer, K.-H.; Jansen, J.l.C.

    2003-01-01

    Quantitative fluorescence in situ hybridization (FISH) and the combination of FISH with microautoradiography (MAR) were used in order to study the long-term population dynamics (2.5 years) and the in situ physiology in two parallel activated sludge pilot systems with enhanced biological phosphorus...... removal (EBPR). The two systems received the same influent wastewater, but were differently operated (with and without nitrogen removal, respectively). Both systems showed a significant P removal that increased when different substrates (phosphorus (P), acetate and glucose, respectively) were added to the....... However, we observed a lower correlation (0.9). The Actinobacteria were the only additional group of bacteria which showed a similar degree of correlation to the P content in activated sludge as the Rhodocyclus-related bacteria - but only for the system without nitrogen removal. Significant amounts (less...

  13. Long-term population dynamics and in situ physiology in activated sludge systems with enhanced biological phosphorus removal operated with and without nitrogen removal

    DEFF Research Database (Denmark)

    Lee, N.; Nielsen, P.H.; Aspegren, H.;

    2003-01-01

    removal (EBPR). The two systems received the same influent wastewater, but were differently operated (with and without nitrogen removal, respectively). Both systems showed a significant P removal that increased when different substrates (phosphorus (P), acetate and glucose, respectively) were added......Quantitative fluorescence in situ hybridization (FISH) and the combination of FISH with microautoradiography (MAR) were used in order to study the long-term population dynamics (2.5 years) and the in situ physiology in two parallel activated sludge pilot systems with enhanced biological phosphorus....... However, we observed a lower correlation (0.9). The Actinobacteria were the only additional group of bacteria which showed a similar degree of correlation to the P content in activated sludge as the Rhodocyclus-related bacteria - but only for the system without nitrogen removal. Significant amounts (less...

  14. A DO- and pH-based early warning system of nitrification inhibition for biological nitrogen removal processes.

    Science.gov (United States)

    Hong, Seil; Choi, Il; Lim, Byung Jin; Kim, Hyunook

    2012-01-01

    In Korea, more than 80% of municipal wastewater treatment plants (WWTPs) with capacities of 500 m3·d-1 or more are capable of removing nitrogen from wastewater through biological nitrification and denitrification processes. Normally, these biological processes show excellent performance, but if a toxic chemical is present in the influent to a WWTP, the biological processes (especially, the nitrification process) may be affected and fail to function normally; nitrifying bacteria are known very vulnerable to toxic substances. Then, the toxic compound as well as the nitrogen in wastewater may be discharged into a receiving water body without any proper treatment. Moreover, it may take significant time for the process to return back its normal state. In this study, a DO- and pH-based strategy to identify potential nitrification inhibition was developed to detect early the inflow of toxic compounds to a biological nitrogen removal process. This strategy utilizes significant changes observed in the oxygen uptake rate and the pH profiles of the mixed liquor when the activity of nitrifying bacteria is inhibited. Using the strategy, the toxicity from test wastewater with 2.5 mg·L-1 Hg2+, 0.5 mg·L-1 allythiourea, or 0.25 mg·L-1 chloroform could be successfully detected. PMID:23443381

  15. Long-term study on the impact of temperature on enhanced biological phosphorus and nitrogen removal in membrane bioreactor.

    Science.gov (United States)

    Sayi-Ucar, N; Sarioglu, M; Insel, G; Cokgor, E U; Orhon, D; van Loosdrecht, M C M

    2015-11-01

    The study involved experimental observation and performance evaluation of a membrane bioreactor system treating municipal wastewater for nutrient removal for a period 500 days, emphasizing the impact of high temperature on enhanced biological phosphorus removal (EBPR). The MBR system was operated at relatively high temperatures (24-41 °C). During the operational period, the total phosphorus (TP) removal gradually increased from 50% up to 95% while the temperature descended from 41 to 24 °C. At high temperatures, anaerobic volatile fatty acid (VFA) uptake occurred with low phosphorus release implying the competition of glycogen accumulating organisms (GAOs) with polyphosphate accumulating organisms (PAOs). Low dissolved oxygen conditions associated with high wastewater temperatures did not appreciable affected nitrification but enhanced nitrogen removal. Dissolved oxygen levels around 1.0 mgO2/L in membrane tank provided additional denitrification capacity of 6-7 mgN/L by activating simultaneous nitrification and denitrification. As a result, nearly complete removal of nitrogen could be achieved in the MBR system, generating a permeate with no appreciable nitrogen content. The gross membrane flux was 43 LMH corresponding to the specific permeability (K) of 413 LMH/bar at 39 °C in the MBR tank. The specific permeability increased by the factor of 43% at 39 °C compared to that of 25 °C during long-term operation. PMID:26204227

  16. Enhanced biological nitrogen removal in MLE combined with post-denitrification process and EF clarifier.

    Science.gov (United States)

    Chung, C M; Cho, K W; Kim, Y J; Yamamoto, K; Chung, T H

    2012-05-01

    A modified ludzack ettinger reactor (MLE) combined with a post-denitrification reactor (PDMLE) using electroflotation (EF) as a secondary clarifier was investigated on its feasibility and process performance. Results indicated that higher mixed liquor suspended solids (MLSS) concentrations in bioreactor (5,350 ± 352 mg L(-1)) were maintained via the highly concentrated return sludge (16,771 ± 991 mg L(-1)) from the EF clarifier and the effluent suspended solids (SS) concentrations continued relatively low, representing effluent SS concentration of 1.71 ± 1.16 mg L(-1), compared with GS-A2O process during the operation of four months. The denitrification was improved by combining MLE process with post-denitrification based on endogenous decay (i.e. no additional carbon source was added), resulting in the removal efficiencies of TN were about 91 and 59% for the influent C/N ratio of 10 and 5, respectively, revealing relatively high nitrogen removal as compared with EF-A2O and gravity settling (GS)-A2O processes as a control. The nitrogen balance analysis indicates that pre-denitrification and post-denitrification contributed to 78 and 22% of TN removed, respectively. PMID:21947625

  17. Fate of dissolved organic nitrogen during biological nutrient removal wastewater treatment processes.

    Science.gov (United States)

    Liu, Bing; Lin, Huirong; Yu, Guozhong; Zhang, Shenghua; Zhao, Chengmei

    2013-04-01

    Due to its potential to form toxic nitrogenous disinfection byproducts (N-DBPs), dissolved organic nitrogen (DON) is considered as one of the most important parameters in wastewater treatment plants (WWTP). This study describes a comprehensive investigation of variations in DON levels in orbal oxidation ditches. The results showed that DON increased gradually from 0.71 to 1.14 mg I(-1) along anaerobic zone, anoxic zone, aerobic zone 1 and aerobic 2. Molecular weight fractionation of DON in one anaerobic zone and one aerobic zone (aerobic zone 2) was performed. We found that the proportion of small molecular weight ( 20 kDa) showed opposite trend. This variation may have been caused due to the release of different types of soluble microbial products (SMPs) during biological processes. These SMPs contained both tryptophan protein-like and aromatic protein-like substances, which were confirmed by three-dimensional excitation-emission matrix (EEM) analysis. PMID:24620601

  18. Enhanced Biological Phosphorus Removal from Dairy Manure to Meet Nitrogen:Phosphorus Crop Nutrient Requirements

    OpenAIRE

    Yanosek, Kristina Anne

    2002-01-01

    Over the last two decades, livestock operations have become highly concentrated due to growing trends towards larger, more confined facilities and a decrease in cropland on smaller farms. This has led to greater amounts of excess manure nutrients on farms, increasing the potential for nutrient pollution of water bodies from runoff. The purpose of this study was to determine if enhanced biological phosphorus removal (EBPR) is a viable alternative for managing excess manure nutrients on dairy...

  19. 污废水生物脱氮除磷技术研究进展%Research Status of Technologies for Nitrogen and Phosphorus Removal by Biological Processes

    Institute of Scientific and Technical Information of China (English)

    刘启承

    2013-01-01

      总结了目前城市污水生物脱氮除磷技术研究及应用进展,分析了脱氮除磷工艺机理及其特点,探讨了城市污水生物脱氮除磷工艺深入研究的方向。%This paper reviews the advances in the biological nitrogen and phosphorus removal technologies for municipal wastewater .The mechanism and characteristics of nitrogen and phosphorus removal processes are analyzed , and directions of studying the biological nitrogen and phosphorus removal technologies are also discussed .

  20. Combined Pre-Precipitation, Biological Sludge Hydrolysis and Nitrogen Reduction - A Pilot Demonstration of Integrated Nutrient Removal

    DEFF Research Database (Denmark)

    Kristensen, G. H.; Jørgensen, P. E.; Strube, R.;

    1992-01-01

    A pilot study was performed to investigate advanced wastewater treatment by pre-precipitation in combination with biological nitrogen removal supported by biological sludge hydrolysis. The influent wastewater was pretreated by addition of a pre-polymerized aluminum salt, followed by flocculation...... and sedimentation. Chemical pretreatment resulted in 60% COD-reduction and 75% phosphorus reduction. The chemically precipitated primary sludge was exposed to anaerobic sludge hydrolysis at retention times of 1 and 2 days at temperatures in the range of 15-30°C. At a retention time of two days at 20°C, resulting......, resulting in high denitrification rates. Nitrogen reduction was performed based on the Bio-Denitro principle in an activated sludge system. Nitrogen was reduced from 45 mg/l to 9 mg/l and phosphorus was reduced from 11 mg/l to 0.5 mg/l. The sludge yield was low, approx. 0.3-0.4 gCOD/gCOD removed...

  1. Instability of biological nitrogen removal in a cokes wastewater treatment facility during summer

    International Nuclear Information System (INIS)

    Failure in nitrogen removal of cokes wastewater occurs occasionally during summer season (38 deg. C) due to the instability of nitrification process. The objective of this study was to examine why the nitrification process is unstable especially in summer. Various parameters such as pH, temperature, nutrients and pollutants were examined in batch experiments using activated sludge and wastewater obtained from a full-scale cokes wastewater treatment facility. Batch experiments showed that nitrification rate of the activated sludge was faster in summer (38 deg. C) than in spring or autumn (29 deg. C) and the toxic effects of cyanide, phenol and thiocyanate on nitrification were reduced with increasing temperature. Meanwhile, experiment using continuous reactor showed that the reduction rate in nitrification efficiency was higher at 38 deg. C than at 29 deg. C. In conclusion, the instability of full-scale nitrification process in summer might be mainly due to washing out of nitrifiers by fast growth of competitive microorganisms at higher temperature under increased concentrations of phenol and thiocyanate

  2. Optimization of operation conditions for the startup of aerobic granular sludge reactors biologically removing carbon, nitrogen, and phosphorous.

    Science.gov (United States)

    Lochmatter, Samuel; Holliger, Christof

    2014-08-01

    The transformation of conventional flocculent sludge to aerobic granular sludge (AGS) biologically removing carbon, nitrogen and phosphorus (COD, N, P) is still a main challenge in startup of AGS sequencing batch reactors (AGS-SBRs). On the one hand a rapid granulation is desired, on the other hand good biological nutrient removal capacities have to be maintained. So far, several operation parameters have been studied separately, which makes it difficult to compare their impacts. We investigated seven operation parameters in parallel by applying a Plackett-Burman experimental design approach with the aim to propose an optimized startup strategy. Five out of the seven tested parameters had a significant impact on the startup duration. The conditions identified to allow a rapid startup of AGS-SBRs with good nutrient removal performances were (i) alternation of high and low dissolved oxygen phases during aeration, (ii) a settling strategy avoiding too high biomass washout during the first weeks of reactor operation, (iii) adaptation of the contaminant load in the early stage of the startup in order to ensure that all soluble COD was consumed before the beginning of the aeration phase, (iv) a temperature of 20 °C, and (v) a neutral pH. Under such conditions, it took less than 30 days to produce granular sludge with high removal performances for COD, N, and P. A control run using this optimized startup strategy produced again AGS with good nutrient removal performances within four weeks and the system was stable during the additional operation period of more than 50 days. PMID:24784454

  3. Investigation of the effect of free ammonia concentration upon leachate treatment by shortcut biological nitrogen removal process.

    Science.gov (United States)

    Chung, Jinwook; Bae, Wookeun; Lee, Yong-Woo; Ko, Gwang-Beom; Lee, Sang-Uk; Park, Seong-Jun

    2004-01-01

    A shortcut biological nitrogen removal (SBNR) process was operated to treat an ammonium rich landfill leachate using a pilot-scale reactor. The SBNR process was intended to oxidize ammonia to nitrite and, then, to reduce it to nitrogen gas. When the hydraulic retention time was 4-3 days, a half of the ammonium oxidized was accumulated as nitrite in the oxidation tank. The nitrite was denitrified completely in the anoxic tank when recycled. The average free ammonia (FA) concentration in the ammonium oxidation tank was 3.7 mg/L. The specific substrate utilization rates of ammonium oxidizers and nitrite oxidizers were investigated at varying FA concentrations through batch experiments. The highest specific ammonium oxidation rate was observed when the FA concentration was 10 mg/L. The rate decreased slightly when the FA concentration was increased to 20 or 50 mg/L, or decreased significantly when it was 5 mg/L. In case of nitrite oxidation, the specific nitrite utilization rate decreased significantly with increasing FA concentration up to 10 mg/L. Consequently, the optimal FA concentration in leachate treatment was 10 mg/L for maximum nitrite accumulation and maximum ammonium removal, or 5 mg/L for lower ammonium concentration and reasonable nitrite accumulation. PMID:15242116

  4. Respirometry applied for biological nitrogen removal process; Aplicacion de la respirometria al tratamiento biologico para la eliminacion del nitrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, E.

    2004-07-01

    In waste water treatment plants, the Biological Nitrogen Removal (BNR) has acquired a fundamental importance. The BNR processes are Nitrification ( aerobic) and Denitrification (anoxic). Since both processes are carried on living microorganisms, a lack of their bioactivity information might cause serious confusion about their control criteria and following up purposes. For this reason, the Re spirometry applied to those processes has reached an important role by getting an essential information in a timely manner through respiration rate measurements in static and dynamic modes and applications such as AUR (Ammonium Uptake Rate), Nitrification Capacity. RBCOD (Readily Biodegradable COD) as well as AUR related to SRT (Sludge age), RBCOD related to NUR (Specific Nitrate Uptake Rate) and others. By other side in this article we have introduced a not very well known applications related to denitrification, about the methanol acclimatization and generated bioactivity. (Author) 6 refs.

  5. Single stage biological nitrogen removal by nitritation and anaerobic ammonium oxidation in biofilm systems.

    Science.gov (United States)

    Helmer, C; Tromm, C; Hippen, A; Rosenwinkel, K H; Seyfried, C F; Kunst, S

    2001-01-01

    In full scale wastewater treatment plants with at times considerable deficits in the nitrogen balances, it could hitherto not be sufficiently explained which reactions are the cause of the nitrogen losses and which micro-organisms participate in the process. The single stage conversion of ammonium into gaseous end-products--which is henceforth referred to as deammonification--occurs particularly frequently in biofilm systems. In the meantime, one has succeeded to establish the deammonification processes in a continuous flow moving-bed pilot plant. In batch tests with the biofilm covered carriers, it was possible for the first time to examine the nitrogen conversion at the intact biofilm. Depending on the dissolved oxygen (DO) concentration, two autotrophic nitrogen converting reactions in the biofilm could be proven: one nitritation process under aerobic conditions and one anaerobic ammonium oxidation. With the anaerobic ammonium oxidation, ammonium as electron donor was converted with nitrite as electron acceptor. The end-product of this reaction was N2. Ammonium and nitrite did react in a stoichiometrical ratio of 1:1.37, a ratio which has in the very same dimension been described for the ANAMMOX-process (1:1.31 +/- 0.06). Via the oxygen concentration in the surrounding medium, it was possible to control the ratio of nitritation and anaerobic ammonium oxidation in the nitrogen conversion of the biofilm. Both processes were evenly balanced at a DO concentration of 0.7 mg/l, so that it was possible to achieve a direct, almost complete elimination of ammonium without addition of nitrite. One part of the provided ammonium did participate in the nitritation, the other in the anaerobic ammonium oxidation. Through the aerobic ammonium oxidation into nitrite within the outer oxygen supplied layers of the biofilm, the reaction partner was produced for the anaerobic ammonium oxidation within the inner layers of the biofilm. PMID:11379106

  6. Developing and optimizing processes for biological nitrogen removal from tannery wastewaters in Ethiopia

    OpenAIRE

    Leta, Seyoum

    2004-01-01

    In Ethiopia industrial effluents containing high contents of organic matter, nitrogen and heavy metals are discharged into inland surface waters with little or no pre-treatment. Significant pollution concerns related to these effluents include dissolved oxygen depletion, toxicity and eutrophication of the receiving waters. This has not only forced the government to formulate regulations and standards for discharge limits but also resulted in an increasing interest and development of methods a...

  7. Understanding the impact of influent nitrogen concentration on granule size and microbial community in a granule-based enhanced biological phosphorus removal system.

    Science.gov (United States)

    Zou, Jinte; Li, Yongmei; Zhang, Lili; Wang, Ruyi; Sun, Jing

    2015-02-01

    To better understand the effect of influent nitrogen concentration on granule size and microbial community in a granule-based enhanced biological phosphorus removal system, three influent nitrogen concentrations were tested while carbon concentration was an unlimited factor. The results show that although ammonium and phosphate were well removed in the tested nitrogen concentration range (20-50 mg L(-1)), granule size, the amount of phosphate accumulating organisms (PAOs) and microbial activity were affected significantly. A possible mechanism for the effect of influent nitrogen concentration on granule size is proposed based on the experimental results. The increase in proteins/polysaccharides ratio caused by high influent nitrogen concentration plays a crucial role in granule breakage. The small granule size then weakens simultaneous nitrification-denitrification, which further causes higher nitrate concentration in the effluent and lower amount of PAOs in sludge. Consequently, phosphate concentration in the anaerobic phase decreases, which plays the secondary role in granule breakage. PMID:25496940

  8. Autotrophic Biological Denitrification for Complete Removal of Nitrogen from Septic System Wastewater

    International Nuclear Information System (INIS)

    The overall objective of this research was to develop a reliable, robust, and maintenance-free passive system for biological denitrification in on-site wastewater treatment systems. The process relies on sulfur oxidizing denitrifying bacteria in upflow packed bioreactors. Since this process consumes alkalinity, it is necessary to add a solid-phase buffer that can scavenge the H+ as it is generated by the biologically-mediated reaction and arrest the drop in the pH value. This study investigated the use of limestone, marble chips and crushed oyster shell as solid-phase buffers that provide alkalinity.Two bench-scale upflow column reactors and two field-scale bioreactors were constructed and packed with sulfur pellets and an alkalinity source. The pilot scale bioreactors (∼200 L each) were installed at the Massachusetts Alternative Septic System Test Center (MASSTC) in Sandwich, MA. The pilot-scale bioreactors performed better when oyster shell was used as the solid-phase buffer vis-a-vis marble chips. In both (pilot-scale and laboratory-scale) systems, denitrification rates were high with the effluent NO3- -N concentration consistently below 8 mg/L

  9. Uncertainty assessment of a model for biological nitrogen and phosphorus removal: Application to a large wastewater treatment plant

    Science.gov (United States)

    Mannina, Giorgio; Cosenza, Alida; Viviani, Gaspare

    In the last few years, the use of mathematical models in WasteWater Treatment Plant (WWTP) processes has become a common way to predict WWTP behaviour. However, mathematical models generally demand advanced input for their implementation that must be evaluated by an extensive data-gathering campaign, which cannot always be carried out. This fact, together with the intrinsic complexity of the model structure, leads to model results that may be very uncertain. Quantification of the uncertainty is imperative. However, despite the importance of uncertainty quantification, only few studies have been carried out in the wastewater treatment field, and those studies only included a few of the sources of model uncertainty. Seeking the development of the area, the paper presents the uncertainty assessment of a mathematical model simulating biological nitrogen and phosphorus removal. The uncertainty assessment was conducted according to the Generalised Likelihood Uncertainty Estimation (GLUE) methodology that has been scarcely applied in wastewater field. The model was based on activated-sludge models 1 (ASM) and 2 (ASM2). Different approaches can be used for uncertainty analysis. The GLUE methodology requires a large number of Monte Carlo simulations in which a random sampling of individual parameters drawn from probability distributions is used to determine a set of parameter values. Using this approach, model reliability was evaluated based on its capacity to globally limit the uncertainty. The method was applied to a large full-scale WWTP for which quantity and quality data was gathered. The analysis enabled to gain useful insights for WWTP modelling identifying the crucial aspects where higher uncertainty rely and where therefore, more efforts should be provided in terms of both data gathering and modelling practises.

  10. Nitrogen Removal From Dairy Manure Wastewater Using Sequencing Batch Reactors

    OpenAIRE

    Whichard, David P

    2001-01-01

    The purpose of this research was to characterize a flushed dairy manure wastewater and to develop the kinetic and stoichiometric parameters associated with nitrogen removal from the wastewater, as well as to demonstrate experimental and simulated nitrogen removal from the wastewater. The characterization showed that all the wastewaters had carbon to nitrogen ratios large enough for biological nitrogen removal. Analysis of carbon to phosphorus ratios showed that enough carbon is available fo...

  11. Biological Phosphorus Removal in a Moving Bed Biofilm Reactor

    OpenAIRE

    Helness, Herman

    2007-01-01

    Phosphorus (P) and nitrogen (N) removal from municipal wastewater is performed to prevent or reduce eutrophication in the receiving water.Both P and N can be removed physical/chemically as well as biologically. While biological processes have always dominated in N-removal, chemical P-removal is used in many cases. Biological P-removal using enhanced biological phosphorus removal (EBPR) is normally carried out in suspended culture (activated sludge) processes while biological N-removal (throug...

  12. Comparative performance of A2/O and a novel membrane-bioreactor-based process for biological nitrogen and phosphorus removal.

    Science.gov (United States)

    Kim, MinGu; Nakhla, George

    2010-01-01

    The comparison between a novel membrane bioreactor (MBR) system and a conventional anaerobic-anoxic-aerobic (A2/O) system was conducted using synthetic wastewater (SWW) and municipal wastewater (MWW). Each system was operated at an overall hydraulic retention time of 8 hours and solids retention time of 10 days. The MBR exhibited better overall system performance than the A2/O system, in terms of phosphorus removal. Nitrogen removal efficiencies were close in the two systems at 73 to 74% in both runs, while phosphorus removal efficiencies were 96 and 74% (SWW run) and 80 and 75% (MWW run), for the MBR and A2/O, respectively. Effluent soluble chemical oxygen demand (COD) was less than 15 mg/L in the two systems during both runs. Phosphorus uptake by denitrifying phosphate-accumulating organisms accounted for 49% of the total uptake in the MBR compared with 33% in the A2/O during the SWW run. The dynamic test clearly showed that the MBR had better denitrification capacity than the A2/O system. The MWW run indicated that MBR ferments particulate COD better than A2/ O. The effect of the intermediate clarifier on MBR phosphorus removal was significant, with phosphorus uptake of 0.16 g/d in the SWW run and phosphorus release of 0.08 g/d in the MWW run, thus enhancing thetotal phosphorus removal in both cases. PMID:20112540

  13. Aerobic/anoxic post-treatment of anaerobically digested sewage sludge as an alternative to biological nitrogen removal from reject water.

    Science.gov (United States)

    Morras, Mikel; Dosta, J; García-Heras, J L

    2015-05-01

    Stabilisation and biological nitrogen removal (BNR) of anaerobically digested sewage sludge were studied in a post-aeration reactor at pilot scale working under alternating anoxic-aerobic conditions. Digested sludge came from a two-stage anaerobic digestion (thermophilic + mesophilic). The best post-aerator performance was achieved when working at an HRT of 10 days (4 days aerobic; dissolved oxygen of 1.8 mg L(-1)) and VS content in the feed no lower than 6.7 g L(-1). Free ammonia concentration values in the effluent above 1.5 mg N L(-1) (around 150 mg NH4 (+)-N L(-1) at pH 7) were necessary to promote the BNR over nitrite. Removal efficiencies up to 80 % NH4 (+)-N, 50-55 % total nitrogen and 15-20 % VS were recorded in this study, with no external addition of chemicals. A nitrogen mass balance revealed that the high percent of NH4 (+)-N assimilated in heterotrophic growth was counteracted with that released in ammonification and fermentation, leading to a NH4 (+)-N removal mainly related to biological nitritation/denitritation. PMID:25407727

  14. Artificial wetlands performance: nitrogen removal.

    Science.gov (United States)

    Durán-de-Bazúa, Carmen; Guido-Zárate, Alejandro; Huanosta, Thalía; Padrón-López, Rosa Martha; Rodríguez-Monroy, Jesús

    2008-01-01

    Artificial wetlands (AW) are a promising option for wastewater treatment in small communities due to their high performance in nutrients removal and low operation and maintenance costs. Nitrogen can favour the growth of algae in water bodies causing eutrophication when present at high concentrations. Nitrogen can be removed through different mechanisms (e.g. nitrification-denitrification, adsorption and plant uptake). Environmental conditions such as temperature and relative humidity can play an important role in the performance of these systems by promoting the growth of macrophytes such as reeds and cattails (e.g. Phragmites australis, Typha latifolia respectively). In this paper, two AW systems were compared, one located in Mexico City, Mexico at an altitude higher than 2,000 m above the sea level, and the second one located in Villahermosa, Tabasco, Mexico at an a altitude near the sea level (27 m). Both systems comprised five reactors (147-L plastic boxes) filled with volcanic slag and gravel and intermittently fed with synthetic water. The removal nitrogen efficiency found for the system located in Mexico City was higher than that of the Tabasco system (90 and 80% as TKN respectively). The higher temperatures in the Tabasco system did not enhanced the nitrogen removal as expected. PMID:18957747

  15. Impact of salinity on organic matter and nitrogen removal from a municipal wastewater RO concentrate using biologically activated carbon coupled with UV/H2O2.

    Science.gov (United States)

    Pradhan, Shovana; Fan, Linhua; Roddick, Felicity A; Shahsavari, Esmaeil; Ball, Andrew S

    2016-05-01

    The concentrate streams generated from reverse osmosis (RO)-based municipal wastewater reclamation processes contain organic substances and nutrients at elevated concentrations, posing environmental and health risks on their disposal to confined receiving environments such as bays. The impact of salinity (TDS at 7, 10 and 16 g/L) of a RO concentrate (ROC) on the treatment efficiency of a biological activated carbon (BAC) system after pre-oxidation with UV/H2O2 was characterised in terms of removal of organic matter and nitrogen species, and the bacterial communities. Organic matter removal was comparable for the ROC over the tested salinity range, with 45-49% of DOC and 70-74% of UVA254 removed by the combined treatment. However, removal in total nitrogen (TN) was considerably higher for the ROC at the high salinity (TDS ∼ 16 mg/L) compared with the low (∼7 g/L) and medium salinity (∼10 g/L). Effective nitrification with high ammonium removal (>90%) was achieved at all salinity levels, whereas greater denitrification (39%) was obtained at high salinity than low (23%) and medium salinity (27%) which might suggest that the bacterial communities contributing to the greater denitrification were more halotolerant. Microbiological characterisation using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and culture based techniques showed that diversified bacterial communities were present in the BAC system as evident from different 16S rDNA. The major bacterial groups residing on the BAC media belonged to Bacillus (Firmicutes), Pseudomonas (γ-Proteobacteria), and Rhodococcus (Actinobacteria) for all salinity levels, confirming that these microbial communities could be responsible for carbon and nitrogen removal at the different salinity levels. This has implications in understanding the effectiveness and robustness of the BAC system over the salinity range of the ROC and so would be useful for optimising the treatment efficiency of

  16. Nitrogen removal from natural gas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    According to a 1991 Energy Information Administration estimate, U.S. reserves of natural gas are about 165 trillion cubic feet (TCF). To meet the long-term demand for natural gas, new gas fields from these reserves will have to be developed. Gas Research Institute studies reveal that 14% (or about 19 TCF) of known reserves in the United States are subquality due to high nitrogen content. Nitrogen-contaminated natural gas has a low Btu value and must be upgraded by removing the nitrogen. In response to the problem, the Department of Energy is seeking innovative, efficient nitrogen-removal methods. Membrane processes have been considered for natural gas denitrogenation. The challenge, not yet overcome, is to develop membranes with the required nitrogen/methane separation characteristics. Our calculations show that a methane-permeable membrane with a methane/nitrogen selectivity of 4 to 6 would make denitrogenation by a membrane process viable. The objective of Phase I of this project was to show that membranes with this target selectivity can be developed, and that the economics of the process based on these membranes would be competitive. Gas permeation measurements with membranes prepared from two rubbery polymers and a superglassy polymer showed that two of these materials had the target selectivity of 4 to 6 when operated at temperatures below - 20{degrees}C. An economic analysis showed that a process based on these membranes is competitive with other technologies for small streams containing less than 10% nitrogen. Hybrid designs combining membranes with other technologies are suitable for high-flow, higher-nitrogen-content streams.

  17. 污水生物脱氮除磷新技术%New Technology of Biological Nitrogen and Phosphorus Removal in Sewage

    Institute of Scientific and Technical Information of China (English)

    丛晓东; 吕勇; 王肇君

    2012-01-01

    首先简单阐述了生物脱氮除磷机理,然后重点介绍了目前几种污水生物处理新技术:厌氧/缺氧/好氧MBR工艺、短程硝化反硝化工艺和倒置A2/O工艺等,最后对污水生物脱氮除磷技术的发展进行了展望,并提出了一些建议。%In the first part,the mechanism of biological nitrogen and phosphorus removal is simply explained firstly,and then several new technology of sewage biological disposal,such as anoxic/anaerobic/aerobic membrane bioreactor(MBR) process、shortcut nitrification—denitrification process and reversed A2/O process are introduced.In the end,the paper generalized the development of new technology of biological nitrogen and phosphorus removal in sewage,and some suggestions are put forward.

  18. Characterization of an Autotrophic Nitrogen-Removing Biofilm from a Highly Loaded Lab-Scale Rotating Biological Contactor

    OpenAIRE

    Pynaert, Kris; Smets, Barth F.; Wyffels, Stijn; Beheydt, Daan; Siciliano, Steven D.; Verstraete, Willy

    2003-01-01

    In this study, a lab-scale rotating biological contactor (RBC) treating a synthetic NH4+ wastewater devoid of organic carbon and showing high N losses was examined for several important physiological and microbial characteristics. The RBC biofilm removed 89% ± 5% of the influent N at the highest surface load of approximately 8.3 g of N m−2 day−1, with N2 as the main end product. In batch tests, the RBC biomass showed good aerobic and anoxic ammonium oxidation (147.8 ± 7.6 and 76.5 ± 6.4 mg of...

  19. The feasibility of an up-flow partially aerated biological filter (U-PABF) for nitrogen and COD removal from domestic wastewater.

    Science.gov (United States)

    Tao, Chen; Peng, Tong; Feng, Chuanping; Chen, Nan; Hu, Qili; Hao, Chunbo

    2016-10-01

    An up-flow partially aerated biological filter (U-PABF) was developed to study the removal of nitrogen and chemical oxygen demand (COD) from synthetic domestic wastewater. The removal of NH4(+)-N was primarily attributed to adsorption in the zeolite U-PABF and to bioprocesses in the ceramic U-PABF. When the hydraulic retention time (HRT) was 5.2h, the ceramic U-PABF achieved a good performance and the NH4(+)-N, total nitrogen (TN), and COD removal efficiency reached 99.08±8.79%, 72.83±0.68%, and 89.38±1.04%, respectively. The analysis of NH4(+)-N, NO3(-)-N, NO2(-)-N, and TN at different depths revealed the simultaneous existence of nitrification-denitrification, and anaerobic ammonium oxidation (anammox) in ceramic U-PABF. Illumina pyrosequencing confirmed the existence of Planctomycetes, which are responsible for anammox. The results indicated that the nitrification-denitrification and anammox all contributed to the high removal of NH4(+)-N, TN, and COD in the U-PABF. PMID:27372011

  20. Benchmarking Biological Nutrient Removal in Wastewater Treatment Plants

    DEFF Research Database (Denmark)

    Flores-Alsina, Xavier; Gernaey, Krist; Jeppsson, Ulf

    2011-01-01

    This paper examines the effect of different model assumptions when describing biological nutrient removal (BNR) by the activated sludge models (ASM) 1, 2d & 3. The performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) benchmark wastewater treatment plant...

  1. Identification of microorganisms involved in nitrogen removal from wastewater treatment systems by means of molecular biology techniques

    International Nuclear Information System (INIS)

    The identification of the main bacteria populations present in the granular biomass from a biological reactor treating wastewater has been performed by applying two different molecular biology techniques. By means of the DGGE technique five different genera of heterotrophic bacteria (Thiothrix, Thauera, Cloroflexi, Comamonas y Zoogloea) and one of ammonia oxidizing bacteria (Nitrosomanas) were identified. The FISH technique, based on microscopy, allowed the in situ visualization and quantification of those microorganisms. Special attention was paid to filamentous bacteria distribution (Thiothrix and Cloroflexi) which could exert a structural function in aerobic granular sludge. (Author) 26 refs.

  2. Biological nitrogen removal in one step by nitritation and anaerobic oxidation of ammonia in biofilms; Einstufige biologische Stickstoffelimination durch Nitritation und anaerobe Ammonium-Oxidation im Biofilm

    Energy Technology Data Exchange (ETDEWEB)

    Helmer, C.; Tromm, C.; Hippen, A.; Rosenwinkel, K.H.; Seyfried, C.F.; Kunst, S. [Hannover Univ. (Germany). Inst. fuer Siedlungswasserwirtschaft und Abfalltechnik

    1999-07-01

    For biological treatment of high nitrogenous wastewaters with low C/N ratio autotrophic microorganisms which are able to convert ammonium directly into nitrogen gas are especially interesting. It is exceptionally difficult to verify their presence and importance in mixed populations of full scale wastewater treatment plants. So it could not be clarified finally up to now which basic microbial reactions lead to single stage complete nitrogen removal, here called deammonification, in the nitrification step (biological contactor) of the leachate treatment plant in Mechernich. It succeeded meanwhile to establish the process of deammonification in a continuous flow moving-bed pilot plant. In batch experiments which biomass-covered carriers nitrogen conversions could become investigated at the intact biofilm for the first time. Two autotrophic nitrogen conversion reactions could be proved in the biofilm depending on dissolved oxygen (DO) concentration: A nitritation under aerobic conditions and an anaerobic ammonium oxidation. For the anaerobic ammonium oxidation nitrite was used as electron acceptor with ammonium as electron donor. N{sub 2} was the end product of the reaction. The ratio of ammonium conversion to nitrite conversion was 1:1,37, which was described in the same range for the ANAMMOX-process (1:1,31{+-}0,06). Nitrate could not be used as electron acceptor. Nitrite had to be added to the experiment to obtain oxygen independent oxidation of ammonium. The parts of nitritation and anaerobic ammonium conversion in nitrogen conversion could be controlled by the DO concentration. At a DO concentration of 0.7 mg/l both processes were balanced, so that a direct almost complete elimination of ammonium was possible without any dosage of nitrite. The added ammonium was partially oxidised to nitrite and partially oxidised anaerobically. The aerobic ammonium oxidation to nitrite in the outer oxygen supplied biofilm layers produced the reactant for the anaerobic ammonium

  3. New anaerobic process of nitrogen removal.

    Science.gov (United States)

    Kalyuzhnyi, S; Gladchenko, M; Mulder, A; Versprille, B

    2006-01-01

    This paper reports on successful laboratory testing of a new nitrogen removal process called DEAMOX (DEnitrifying AMmonium OXidation) for the treatment of strong nitrogenous wastewater such as baker's yeast effluent. The concept of this process combines the recently discovered ANAMMOX (ANaerobic AMMonium OXidation) reaction with autotrophic denitrifying conditions using sulfide as an electron donor for the production of nitrite within an anaerobic biofilm. The achieved results with a nitrogen loading rate of higher than 1,000 mg/L/d and nitrogen removal of around 90% look very promising because they exceed (by 9-18 times) the corresponding nitrogen removal rates of conventional activated sludge systems. The paper describes also some characteristics of DEAMOX sludge, as well as the preliminary results of its microbiological characterization. PMID:17163025

  4. Biological Phosphorus Removal in a Moving Bed Biofilm Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Helness, Herman

    2007-09-15

    The scope of this study was to investigate use of the moving bed biofilm reactor (MBBR) process for biological phosphorus removal. The goal has been to describe the operating conditions required for biological phosphorus and nitrogen removal in a MBBR operated as a sequencing batch reactor (SBR), and determine dimensioning criteria for such a process

  5. Kinetic Interpretation of Nitrogen Removal in Pilot Scale Experiments

    DEFF Research Database (Denmark)

    Harremoës, Poul; Sinkjær, Ole

    1995-01-01

    biological and chemical phosphorus removal. Nitrification and denitrification rates have been measured in batch tests on activated sludge extracted from the pilot plants and by measuring transient concentrations during the alternating mode of operation in the aerobic and anoxic tanks. The data were......Pilot plant experiments have been performed over a period of four years in order to establish an experimental basis for the upgrading of the treatment plants of The City of Copenhagen to nutrient removal. The choice of design is the alternating mode of operating biological nitrogen removal with...

  6. Kinetic Interpretation of Nitrogen Removal in Pilot Scale Experiments

    DEFF Research Database (Denmark)

    Harremoës, Poul; Sinkjær, Ole

    1995-01-01

    Pilot plant experiments have been performed over a period of four years in order to establish an experimental basis for the upgrading of the treatment plants of The City of Copenhagen to nutrient removal. The choice of design is the alternating mode of operating biological nitrogen removal with...... biological and chemical phosphorus removal. Nitrification and denitrification rates have been measured in batch tests on activated sludge extracted from the pilot plants and by measuring transient concentrations during the alternating mode of operation in the aerobic and anoxic tanks. The data were...

  7. DEAMOX--new biological nitrogen removal process based on anaerobic ammonia oxidation coupled to sulphide-driven conversion of nitrate into nitrite.

    Science.gov (United States)

    Kalyuzhnyi, Sergey; Gladchenko, Marina; Mulder, Arnold; Versprille, Bram

    2006-11-01

    This paper reports about the successful laboratory testing of a new nitrogen removal process called DEAMOX (DEnitrifying AMmonium OXidation) for treatment of typical strong nitrogenous wastewater such as baker's yeast effluent. The concept of this process combines the recently discovered anammox (anaerobic ammonium oxidation) reaction with autotrophic denitrifying conditions using sulphide as an electron donor for the production of nitrite from nitrate within an anaerobic biofilm. To generate sulphide and ammonia, a Upflow Anaerobic Sludge Bed (UASB) reactor was used as a pre-treatment step. The UASB effluent was split and partially fed to a nitrifying reactor (to generate nitrate) and the remaining part was directly fed to the DEAMOX reactor where this stream was mixed with the nitrified effluent. Stable process performance and volumetric nitrogen loading rates of the DEAMOX reactor well above 1000 mgN/l/d with total nitrogen removal efficiencies of around 90% were obtained after long-term (410 days) optimisation of the process. Important prerequisites for this performance are appropriate influent ratios of the key species fed to the DEAMOX reactor, namely influent N-NO(x)/N-NH(4) ratios >1.2 (stoichiometry of the anammox reaction) and influent S-H(2)S/N-NO(3) ratios >0.57 mgS/mgN (stoichiometry of the sulphide-driven denitrification of nitrate to nitrite). The paper further describes some characteristics of the DEAMOX sludge as well as the preliminary results of its microbiological characterisation. PMID:16893559

  8. 复合生物反应器亚硝酸型同步硝化反硝化脱氮%Nitrogen Removal by Simultaneous Nitrification and Denitrification via Nitrite in a Sequence Hybrid Biological Reactor

    Institute of Scientific and Technical Information of China (English)

    王建龙; 彭永臻; 王淑莹; 高永青

    2008-01-01

    Sequence hybrid biological reactor(SHBR)was proposed,and some key control parameters were in-vestigated for nitrogen removal from wastewater by simultaneous nitrification and denitrification(SND)via nitrite.sND via nitrite was achieved in SHBR by controlling demand oxygen(DO)concentration.There was a pro-did not destroy the partial nitrification to nitrite.The results showed that limited air flow rate to cause oxygen defi-ciency in the reactor would eventually induce only nitrification to nitrite and not further to nitrate.Nitrogen removal efficiency was increased with the increase in NAR,that iS,NAR was increased from 60%to 90%,and total nitrogen removal efficiency was increased from 68%t0 85%.The SHBR could tolerate high organic loading rate(OLR),COD and ammonia-nitrogen removal efficiency were greater than92%and 93.5%respectively and it even oper-biofilm positively affected the activated sludge settling capability,and sludge volume index(svi)of activated sludge in SHBR never hit more than 90 ml.g-1 throughout the experiments.

  9. High strength nitrogen removal from nightsoil and piggery wastes.

    Science.gov (United States)

    Choi, E; Eum, Y; Gil, K I; Oa, S W

    2004-01-01

    Nightsoil and piggery wastes generally present high strength organics and nitrogen. This study evaluated the nitrogen removal characteristics with the existing and modified nightsoil and piggery waste treatment plants. The existing conventional plants showed 20 to 40% nitrogen removal, but the modification with SBR or MLE process could remove effectively both nitrogen and organics with the minimum COD/TN and alkalinity/TN ratios of 6 and 3.6, respectively. Nitrite nitrification and denitrification rates obtainable at higher nitrogen loads were faster than the rates of nitrate nitrification and denitrification resulting in less reactor volume requirement. However, the higher nitrogen loads increased the organic loads resulting in the reactor temperature inhibiting nitrification. Thus, a combined treatment with anaerobic digestion with the adjustment of influent bypass rates was proposed to reduce the reactor temperature and the external carbon requirement. The biological treatment could discharge about 1,100 mg/L soluble COD and 50 mg/L soluble nitrogen, respectively. PMID:15137412

  10. Effect of carbon sources on biological nitrogen and phosphorus removal in the municipal wastewater treatment system%碳源对污水处理系统脱氮除磷的影响

    Institute of Scientific and Technical Information of China (English)

    林雨倩; 赵军

    2014-01-01

    The performance of biological nutrient removal (BNR) processes is directly connected to the availability of carbon sources. This study introduces the metabolism mechanisms of carbon sources in each step of biological nitrogen and phosphorus removal processes, and the types and concentrations of carbon sources on the nitrogen and phosphorus removal are also discussed. It was revealed that the effective use of organic substrate including external and internal carbon sources could enhance the purifying performance of the system.%在污水强化生物脱氮除磷系统中,碳源种类及浓度对于处理系统去除效果的高效运行起到重要的作用。通过介绍生物脱氮及除磷各步骤碳源需求的机理,探讨碳源类型及碳源浓度对系统脱氮除磷效果的影响,同时对提高污水碳源浓度常用的手段即增加外碳源及内碳源方法进行分析。

  11. Nitrogen removal techniques in aquaculture for a sustainable production

    OpenAIRE

    Crab, R.; Avnimelech, Y.; Defoirdt, T.; Bossier, P.; Verstraete, W.

    2007-01-01

    As the aquaculture industry intensively develops, its environmental impact increases. Discharges from aquaculture deteriorate the receiving environment and the need for fishmeal and fish oil for fish feed production increases. Rotating biological contactors, trickling filters, bead filters and fluidized sand biofilters are conventionally used in intensive aquaculture systems to remove nitrogen from culture water. Besides these conventional water treatment systems, there are other possible mod...

  12. Nitrogen Removal from Molten Steel under Argon DC Glow Plasma

    Institute of Scientific and Technical Information of China (English)

    SUN Ming-shan; DING Wei-zhong; LU Xiong-gang

    2005-01-01

    Under argon DC glow plasma, the nitrogen removal from molten steel was studied. The experimental result showed that nitrogen mass percent could be reduced to 0.000 8%. The change of polarity had no impact on nitrogen removal when the nitrogen mass percent was low. The mechanism of denitrogenation of molten steel under argon DC glow plasma was discussed.

  13. 间歇曝气和连续曝气对生物脱氮除磷效果的比较%Biological Nitrogen and Phosphorus Removal Efficiency by Intermittent Aeration and Continues Aeration Compared

    Institute of Scientific and Technical Information of China (English)

    潘敏; 黄晓鸣

    2015-01-01

    采用序批式生物反应器SBR系统,考察反应阶段的间歇曝气和连续曝气对模拟生活废水中氮和磷的去除效果。研究表明: IASBR和SBR对NH4+-N的去除率分别为99�30%和98�73%;对PO3-4-P的去除率分别为97�02%和67�47%。间歇曝气SBR对氨氮和磷酸根的去除率比连续曝气SBR高,有利于实现强化生物脱磷过程。间歇曝气SBR出水中氮、磷和COD浓度均达到了我国城镇污水处理厂污染物排放标准(GB 18918—2002)一级标准。%Biological nitrogen and phosphorus removal was investigated by an intermittently aerated sequencing batch reactor IASBR and a sequencing batch reactor SBR . The removal efficiencies of ammonium⁃nitrogen NH4+⁃N were 99�30% and 98�73% respectively in IASBR and SBR in steady operation while phosphorus PO3-4 ⁃P removal efficiencies were 97�02% and 67�47% in IASBR and SBR respectively. The intermittent aeration pattern has better effect for biological phosphorus removal. Effluent NH4+⁃N PO3-4 ⁃P and COD concentrations in the IASBR meets ChinaⅠEmission Standards.

  14. 间歇曝气和连续曝气对生物脱氮除磷效果的比较%Biological Nitrogen and Phosphorus Removal Efficiency by Intermittent Aeration and Continues Aeration Compared

    Institute of Scientific and Technical Information of China (English)

    潘敏; 黄晓鸣

    2015-01-01

    Biological nitrogen and phosphorus removal was investigated by an intermittently aerated sequencing batch reactor IASBR and a sequencing batch reactor SBR . The removal efficiencies of ammonium⁃nitrogen NH4+⁃N were 99�30% and 98�73% respectively in IASBR and SBR in steady operation while phosphorus PO3-4 ⁃P removal efficiencies were 97�02% and 67�47% in IASBR and SBR respectively. The intermittent aeration pattern has better effect for biological phosphorus removal. Effluent NH4+⁃N PO3-4 ⁃P and COD concentrations in the IASBR meets ChinaⅠEmission Standards.%采用序批式生物反应器SBR系统,考察反应阶段的间歇曝气和连续曝气对模拟生活废水中氮和磷的去除效果。研究表明: IASBR和SBR对NH4+-N的去除率分别为99�30%和98�73%;对PO3-4-P的去除率分别为97�02%和67�47%。间歇曝气SBR对氨氮和磷酸根的去除率比连续曝气SBR高,有利于实现强化生物脱磷过程。间歇曝气SBR出水中氮、磷和COD浓度均达到了我国城镇污水处理厂污染物排放标准(GB 18918—2002)一级标准。

  15. Operation and control of SBR processes for enhanced biological nutrient removal from wastewater

    OpenAIRE

    Puig Broch, Sebastià

    2008-01-01

    In the last decades, the awareness of environmental issues has increased in society considerably. There is an increasing need to improve the effluent quality of domestic wastewater treatment processes. This thesis describes the application of the Sequencing Batch Reactor (SBR) technology for Biological Nutrient Removal (BNR) from the wastewater. In particular, the work presented evolves from the nitrogen removal to the biological nutrient removal (i.e. nitrogen plus phosphorous removal) with ...

  16. Possibilities of implementing nitrogen removal at Swedish wastewater treatment plants

    International Nuclear Information System (INIS)

    Problems related to eutrophication and oxygen consumption have been considered as the major factors in deterioration of the water quality in Swedish lakes, rivers and coastal areas. Technical solutions to reduce oxygen-consuming materials and eutrophication have up to now been directed towards the removal of biochemical oxygen demand (BOD) and phosphorus. Thus, biological and chemical treatment of municipal wastewater is usually prescribed, and at present about 90% of the municipal wastewater from Swedish urban areas is treated both biologically and chemically. Most plants are designed for post-precipitation, although the treatment plants may now be operated in a modified way, for example, with the use of preprecipitation, two-point precipitation or recirculation of chemical sludges. Hultman and Moore (1982) have presented an overview of Swedish practice in municipal wastewater treatment. Although Swedish treatment of municipal wastewater concentrates on the removal of biochemical oxygen demand and phosphorus, the environmental and operational effects of nitrogen have been discussed for many years

  17. Biological Nutrient Removal in Compact Biofilm Systems

    NARCIS (Netherlands)

    Bassin, J.P.

    2012-01-01

    The removal of nutrients such as nitrogen and phosphorus from both domestic and industrial wastewaters is imperative since they potentially harm the environment. One of the main consequences of excessive availability of nitrogen and phosphorus in aquatic ecosystems (freshwater, marine and estuarine)

  18. Improvement of a manageability of biological nitrogen and phosphorus removal plant using a wastewater treatment process simulator; Gesui shori purosesu shimyureta no riyo ni yoru seibutsuteki chisso/rin jokyo puranto no kanrisei no kojo

    Energy Technology Data Exchange (ETDEWEB)

    Kurata, G. [Toyohashi Univ. of Technology, Aichi (Japan). Faculty of Engineering; Tsumura, K. [Kyoto Univ., Kyoto (Japan). Graduate School; Yamamoto, Y. [Osaka Prefectural Inst. of Public Health, Osaka (Japan)

    1997-02-10

    In this paper, a method for executing a stable management of wastewater treatment process is examined by using a wastewater treatment process simulator with the facilities adopting intermittently aerated 2-tank activated sludge process as the object. The following results are obtained from said examination. Based on a fact that the treatment efficiency is influenced greatly by the comparatively miner parts of the process in biological nitrogen and phosphorus removal, a wastewater treatment process simulator, by which the intrinsic process flow, restricting conditions and behaviors of controlling system of each facility can be dealt with, is developed by using object-directional model. As the results of this development, not only the effects approximate to those of actual process can be obtained, but also the trial error and alternation of process flow can be realized in a short time. The serious influence of disappearance of dissolvable organic substance in flow-adjusting tank upon the deterioration of biological phosphorus removal is clarified by the results of the simulation based on the investigation of flowing-in water quality. 12 refs., 13 figs., 4 tabs.

  19. Nitrogen removal from coal gasification wastewater by activated carbon technologies combined with short-cut nitrogen removal process.

    Science.gov (United States)

    Zhao, Qian; Han, Hongjun; Hou, Baolin; Zhuang, Haifeng; Jia, Shengyong; Fang, Fang

    2014-11-01

    A system combining granular activated carbon and powdered activated carbon technologies along with shortcut biological nitrogen removal (GAC-PACT-SBNR) was developed to enhance total nitrogen (TN) removal for anaerobically treated coal gasification wastewater with less need for external carbon resources. The TN removal efficiency in SBNR was significantly improved by introducing the effluent from the GAC process into SBNR during the anoxic stage, with removal percentage increasing from 43.8%-49.6% to 68.8%-75.8%. However, the TN removal rate decreased with the progressive deterioration of GAC adsorption. After adding activated sludge to the GAC compartment, the granular carbon had a longer service-life and the demand for external carbon resources became lower. Eventually, the TN removal rate in SBNR was almost constant at approx. 43.3%, as compared to approx. 20.0% before seeding with sludge. In addition, the production of some alkalinity during the denitrification resulted in a net savings in alkalinity requirements for the nitrification reaction and refractory chemical oxygen demand (COD) degradation by autotrophic bacteria in SBNR under oxic conditions. PACT showed excellent resilience to increasing organic loadings. The microbial community analysis revealed that the PACT had a greater variety of bacterial taxons and the dominant species associated with the three compartments were in good agreement with the removal of typical pollutants. The study demonstrated that pre-adsorption by the GAC-sludge process could be a technically and economically feasible method to enhance TN removal in coal gasification wastewater (CGW). PMID:25458677

  20. Recent advances in nutrient removal and recovery in biological and bioelectrochemical systems.

    Science.gov (United States)

    Nancharaiah, Y V; Venkata Mohan, S; Lens, P N L

    2016-09-01

    Nitrogen and phosphorous are key pollutants in wastewater to be removed and recovered for sustainable development. Traditionally, nitrogen removal is practiced through energy intensive biological nitrification and denitrification entailing a major cost in wastewater treatment. Recent innovations in nitrogen removal aim at reducing energy requirements and recovering ammonium nitrogen. Bioelectrochemical systems (BES) are promising for recovering ammonium nitrogen from nitrogen rich waste streams (urine, digester liquor, swine liquor, and landfill leachate) profitably. Phosphorus is removed from the wastewater in the form of polyphosphate granules by polyphosphate accumulating organisms. Alternatively, phosphorous is removed/recovered as Fe-P or struvite through chemical precipitation (iron or magnesium dosing). In this article, recent advances in nutrients removal from wastewater coupled to recovery are presented by applying a waste biorefinery concept. Potential capabilities of BES in recovering nitrogen and phosphorous are reviewed to spur future investigations towards development of nutrient recovery biotechnologies. PMID:27053446

  1. Effect of powdered activated carbon technology on short-cut nitrogen removal for coal gasification wastewater.

    Science.gov (United States)

    Zhao, Qian; Han, Hongjun; Xu, Chunyan; Zhuang, Haifeng; Fang, Fang; Zhang, Linghan

    2013-08-01

    A combined process consisting of a powdered activated carbon technology (PACT) and short-cut biological nitrogen removal reactor (SBNR) was developed to enhance the removal efficiency of the total nitrogen (TN) from the effluent of an upflow anaerobic sludge bed (UASB) reactor, which was used to treat coal gasification wastewater (CGW). The SBNR performance was improved with the increasing of COD and TP removal efficiency via PACT. The average removal efficiencies of COD and TP in PACT were respectively 85.80% and 90.30%. Meanwhile, the NH3-N to NO2-N conversion rate was achieved 86.89% in SBNR and the total nitrogen (TN) removal efficiency was 75.54%. In contrast, the AOB in SBNR was significantly inhibited without PACT or with poor performance of PACT in advance, which rendered the removal of TN. Furthermore, PAC was demonstrated to remove some refractory compounds, which therefore improved the biodegradability of the coal gasification wastewater. PMID:23735800

  2. Nutrient release, recovery and removal from waste sludge of a biological nutrient removal system.

    Science.gov (United States)

    Wang, Yi; Zheng, Shu-Jian; Pei, Li-Ying; Ke, Li; Peng, Dang-Cong; Xia, Si-Qing

    2014-01-01

    The uncontrolled release of nutrients from waste sludge results in nitrogen and phosphorus overloading in wastewater treatment plants when supernatant is returned to the inlet. A controlled release, recovery and removal of nutrient from the waste sludge of a Biological Nutrient Removal system (BNR) are investigated. Results showed that the supernatant was of high mineral salt, high electrical conductivity and poor biodegradability, in addition to high nitrogen and phosphorus concentrations after the waste sludge was hydrolysed through sodium dodecyl sulphate addition. Subsequently, over 91.8% of phosphorus and 10.5% of nitrogen in the supernatants were extracted by the crystallization method under the conditions of 9.5 pH and 400 rpm. The precipitate was mainly struvite according to X-ray diffraction and morphological examination. A multistage anoxic-oxic Moving Bed Biofilm Reactor (MBBR) was then adopted to remove the residual carbon, nitrogen and phosphorus in the supernatant. The MBBR exhibited good performance in simultaneously removing carbon, nitrogen and phosphorus under a short aeration time, which accounted for 31.25% of a cycle. Fluorescence in situ hybridization analysis demonstrated that nitrifiers presented mainly in floc, although higher extracellular polymeric substance content, especially DNA, appeared in the biofilm. Thus, a combination of hydrolysis and precipitation, followed by the MBBR, can complete the nutrient release from the waste sludge of a BNR system, recovers nutrients from the hydrolysed liquor and removes nutrients from leftovers effectively. PMID:25176308

  3. Biological Nutrient Removal in Compact Biofilm Systems

    OpenAIRE

    Bassin, J.P.

    2012-01-01

    The removal of nutrients such as nitrogen and phosphorus from both domestic and industrial wastewaters is imperative since they potentially harm the environment. One of the main consequences of excessive availability of nitrogen and phosphorus in aquatic ecosystems (freshwater, marine and estuarine) is the overgrowth of algae and other aquatic plants, a phenomenon designated as eutrophication. Algae and aquatic plants induce depletion of oxygen in water basins, resulting in massive death of e...

  4. 15N in biological nitrogen fixation studies

    International Nuclear Information System (INIS)

    A bibliography with 298 references on the use of the stable nitrogen isotope 15N in the research on the biological fixation of dinitrogen is presented. The literature pertaining to this bibliography covers the period from 1975 to the middle of 1985. (author)

  5. Rape nitrogen nutrition diagnosis using continuum-removed hyperspectral reflectance

    Science.gov (United States)

    Zhang, Xuehong; Tian, Qingjiu

    2008-12-01

    The hyperspectral reflectance for rape fresh leaves and data of chlorophyll and total nitrogen content were acquired in primary growth stages under different nitrogen levels in order to monitor rape status and diagnose nitrogen using remote sensing method. A new method was developed for estimating the nitrogen nutrition of rape using continuum-removed method, which generally used in spectral analysis on rock and mineral. Based on the continuum-removed treatment and the correlation between absorption feature parameters and total nitrogen content of fresh leaves, results show that reflectance at the visible region decreased with increasing in the nitrogen fertilization, and continuum-removed operation can magnify the subtle difference in spectral absorption characteristics arose from the nitrogen stress on rape. During the seeding stage, bud-emerging stage and flowering stage of rape, total area of absorption peak, area left of the absorption peak and area right of the absorption peak in 550-750 nm region increased with increasing in the nitrogen fertilization, but it was opposite for the area-normalized maximal absorption depth. The correlation analysis indicated that it is at seeding stage that the relation between absorption characteristics parameters and leaf total nitrogen was best close. The research demonstrated that continuum-removed method is a feasible method for quantificational evaluation of rape nitrogen nutrition, and the seeding stage of rape is the best stage for assessment of rape nitrogen nutrition based on absorption characteristics of fresh leaves.

  6. Enhanced Biological Phosphorus Removal for Liquid Dairy Manure

    OpenAIRE

    Hong, Yanjuan

    2009-01-01

    Enhanced biological phosphorus removal (EBPR) has been widely used in municipal wastewater treatment, but no previous studies have examined the application of EBPR to treat dairy manure. This study was conducted to evaluate the (i) performance of pilot-scale EBPR systems treating liquid dairy manure, to balance the ratio of nitrogen to phosphorus in manure to meet crop nutrient requirements, (ii) effects of dissolved oxygen and solids retention time on the efficiency of EBPR, and (iii) effect...

  7. Circulating fluidized bed biological reactor for nutrients removal

    Institute of Scientific and Technical Information of China (English)

    Yubo CUI; Hongbo LIU; Chunxue BAI

    2008-01-01

    A new biological nitrogen removal process, which is named herein "The circulating fluidized bed bio-reactor (CFBBR)", was developed for simultaneous removal of nitrogen and organic matter. This process was composed of an anaerobic bed (Riser), aerobic bed (Downer) and connecting device. Influent and nitrified liquid from the aerobic bed enters the anaerobic bed from the bottom of the anaerobic bed, completing the removal of nitrogen and organic matter. The system performance under the conditions of different inflow loadings and nitrified liquid recirculation rates ranging from 200% to 600% was examined. From a technical and economic point of view, the optimum nitrified liquid recirculation rate was 400%. With a shortest total retention time of 2.5 h (0.8 h in the anaerobic bed and 1.5 h in the aerobic bed) and a nitrified liquid recir-culation rate of 400% based on the intluent flow rate, the average removal efficiencies of total nitrogen (TN) and sol-uble chemical oxygen demand (SCOD) were found to be 88% and 95%, respectively. The average effluent concentra-tions of TN and SCOD were 3.5 mg/L and 16 mg/L, respectively. The volatile suspended solid (VSS) concentra-tion, nitrification rate and denitrification rate in the system were less than 1.0 g/L, 0.026-0.1 g NH4+-N/g VSS.d, and 0.016-0.074 g NOx--N/g VSS.d, respectively.

  8. Research progress of biological nitrogen removal by microbial fuel cell%微生物燃料电池在污水生物脱氮中的研究进展

    Institute of Scientific and Technical Information of China (English)

    赵慧敏; 李晓玲; 赵剑强

    2016-01-01

    Microbial fuel cell (MFC) is a new technology for wastewater treatment while generating electricity simultaneously. Applying MFC to nitrogen removal makes the system denitrification MFC or simultaneous nitrification and denitrification (SND) MFC. This paper firstly gave an introduction on the development of biological denitrification in MFC system. Then we analyzed factors influencing MFC nitrogen removal efficiency. The analysis was mainly focused on the MFC configuration (space configuration,electrode materials,separation materials),the operation conditions (nitrogen components concentrations,HRT,dissolved oxygen,carbon source and C/N ratio,temperature,pH,external resistance),as well as the gene expression and diversity of denitrifying bacteria in systems. Finally, suggestions were proposed as following:developing high economic and efficient electrode materials with strong electron transfer ability and ammonia oxidation catalytic function,optimizing the operation conditions of the MFC denitrification systems and analyzing nitrogen removal mechanism,and screening efficient denitrification bacteria through the analysis of microbial community structure in MFC denitrification systems.%微生物燃料电池(MFC)是一种新型污水处理技术,其在处理污水的同时能产生电能,引起众多研究者的关注。将MFC应用于含氮污水的处理中便形成了反硝化或同步硝化反硝化MFC系统。本文回顾了MFC生物脱氮的发展历程,并从 MFC 实验装置的设计构造(空间构型、电极材料、分隔材料)、影响因素(含氮污染物浓度、水力停留时间、溶解氧、碳源与碳氮比、温度、pH 值、外电阻)和反硝化细菌的基因表达与多样性等3个方面进行了综述与分析,提出需要从以下方面进行MFC生物脱氮效能的强化:开发具有强电子传输能力和氨氧化催化功能的廉价高效电极材料,优化 MFC 脱氮的运行条件和探索不同环境下

  9. Benchmarking Biological Nutrient Removal in Wastewater Treatment Plants:Influence of Mathematical Model Assumptions

    OpenAIRE

    Flores-Alsina, Xavier; Gernaey, Krist; Jeppsson, Ulf

    2011-01-01

    This paper examines the effect of different model assumptions when describing biological nutrient removal (BNR) by the activated sludge models (ASM) 1, 2d & 3. The performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) benchmark wastewater treatment plant was compared for a series of model assumptions. Three different model approaches describing BNR are considered. In the reference case, the original model implementations are used to simulate WWTP...

  10. Simultaneous nitrogen and phosphorus removal under low dissolved oxygen conditions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A full-scale test was operated by using low dissolved oxygen activated sludge process to enhance biological nitrogen and phosphorus removal. When the influent concentrations of CODCr, TN and TP varied in a range of 352.9 mg/L-1338.2 mg/L, 34.4 mg/L-96.3 mg/L, and 2.21 mg/L-24.0 mg/L, the average removal efficiencies were 94.9%, 86.7% and 93.0%, respectively. During the test period of two months, effluent meas of CODCr, BOD5, NH3-N, TN and TP were below 50 mg/L, 25 mg/L, 10 mg/L and 1.0 mg/L, respectively. The low dissolved oxygen activated sludge process has a simple flow sheet, fewer facilities and high N and P removal efficiency. It is very convenient to retrofit the conventional activated sludge process with the above process.

  11. Nitrogen removal in Northern peatlands treating mine wastewaters

    Science.gov (United States)

    Palmer, Katharina; Karlsson, Teemu; Turunen, Kaisa; Liisa Räisänen, Marja; Backnäs, Soile

    2015-04-01

    Natural peatlands can be used as passive purification systems for mine wastewaters. These treatment peatlands are well-suited for passive water treatment as they delay the flow of water, and provide a large filtration network with many adsorptive surfaces on plant roots or soil particles. They have been shown to remove efficiently harmful metals and metalloids from mine waters due to variety of chemical, physical and biological processes such as adsorption, precipitation, sedimentation, oxidation and reduction reactions, as well as plant uptake. Many factors affect the removal efficiency such as inflow water quality, wetland hydrology, system pH, redox potential and temperature, the nature of the predominating purification processes, and the presence of other components such as salts. However, less attention has been paid to nitrogen (N) removal in peatlands. Thus, this study aimed to assess the efficiency of N removal and seasonal variation in the removal rate in two treatment peatlands treating mine dewatering waters and process effluent waters. Water sampling from treatment peatland inflow and outflow waters as well as pore waters in peatland were conducted multiple times during 2012-2014. Water samples were analysed for total N, nitrate-N and ammonium-N. Additionally, an YSI EXO2 device was used for continuous nitrate monitoring of waters discharged from treatment peatlands to the recipient river during summer 2014. The results showed that the oxic conditions in upper peat layer and microbial activity in treatment peatlands allowed the efficient oxidation of ammonium-N to nitrite-N and further to nitrate-N during summer time. However, the slow denitrification rate restricts the N removal as not all of the nitrate produced during nitrification is denitrified. In summer time, the removal rate of total N varied between 30-99 % being highest in late summer. N removal was clearly higher for treatment peatland treating process effluent waters than for peatland

  12. Ammoniacal nitrogen removal from groundwaters using natural and synthetic zeolites

    OpenAIRE

    Matsiyevska, Oksana; Chverenchuk, Andrii; Soprunko, Svitlana; Berezyuk, Roman; Pidlisny, Bogdan

    2013-01-01

    In article results of ammoniacal nitrogen occurrence ways into groundwaters analysis was represented. NH4+ removing effectivity from simulative solutions by natural (Sokyrnytsia minefield, Ukraine) and synthetic zeolites was compared.

  13. Effect of solids retention time and wastewater characteristics on biological phosphorus removal

    DEFF Research Database (Denmark)

    Henze, Mogens; Aspegren, H.; Jansen, J.l.C.; Nielsen, P.H.; Lee, N.

    2002-01-01

    The paper deals with the effect of wastewater, plant design and operation in relation to biological nitrogen and phosphorus removal and the possibilities to model the processes. Two Bio-P pilot plants were operated for 2.5 years in parallel receiving identical wastewater. The plants had SRT of 4...... significant variations with time which has importance in relation to modelling. The overall conclusion of the comparison between the two plants is that the biological phosphorus removal efficiency under practical operating conditions is affected by the SRT in the plant and the wastewater composition. Thus...... valuable in verification of models for Nitrogen and Enhanced Biological Phosphorus Removal....

  14. Removal of nitrogen leaching from vegetable crops in constructed wetlands

    NARCIS (Netherlands)

    Haan, de J.J.; Clevering, O.A.; Schoot, van der J.R.; Verstegen, H.A.G.

    2008-01-01

    Vegetable growing leads to high nitrogen emissions. In the Netherlands, nitrogen emissions can hardly be reduced by reducing fertilization without risks for yield and quality loss. An alternative measure to reduce emissions is to collect nitrate-rich drain water and remove nitrate from the drain wat

  15. Biological Nitrogen Fixation: Perspective and Limitation

    OpenAIRE

    N.D Purwantari

    2008-01-01

    The demand of chemical fertilizer, N in particular will be increasing until 2020. In Indonesia, the demand of fertilizer from 1999 – 2002 increased 37.5 and 12.4% for urea and ammonium sulphate, respectively. At the same time, the price of this fertilizer is also increasing and it can not be afforded by the farmer. Other problem in using chemical fertilizer is damaging to the soil and environment. One of the problem solvings for this condition is to maximize biological nitrogen fixation (BNF)...

  16. Optimization of an Sbr process for nitrogen removal from concentrated wastewater via nitrite

    International Nuclear Information System (INIS)

    The results of an experimentation carried out on a pilot-scale Sbr for nitrogen removal via nitridation-denitration are reported. The experimentation was carried out in the period July October 2007 and was aimed at achieving design data for the upgrade of a full scale wastewater treatment plant (WWTP), following the new regulations issued by Lombardy Regional Authority for the discharge of effluents into sensitive areas. One aspect that has been considered in the upgrade is nitrogen removal from the supernatant coming from anaerobic sludge digestion. The experimental results provided sound design data based on real biological activity measurements and operational process parameters such as oxygen and organic carbon requirements.

  17. Nitrogen removal from on-site treated anaerobic effluents using intermittently aerated moving bed biofilm reactors at low temperature.

    Science.gov (United States)

    Luostarinen, Sari; Luste, Sami; Valentín, Lara; Rintala, Jukka

    2006-05-01

    On-site post-treatment of anaerobically pre-treated dairy parlour wastewater (DPWWe; 10 degrees C) and mixture of kitchen waste and black water (BWKWe; 20 degrees C) was studied in moving bed biofilm reactors (MBBR). The focus was on removal of nitrogen and of residual chemical oxygen demand (COD). Moreover, the effect of intermittent aeration and continuous vs. sequencing batch operation was studied. All MBBRs removed 50-60% of nitrogen and 40-70% of total COD (CODt). Complete nitrification was achieved, but denitrification was restricted by lack of carbon. Nitrogen removal was achieved in a single reactor by applying intermittent aeration. Continuous and sequencing batch operation provided similar nitrogen and COD removal, wherefore simpler continuous feeding may be preferred for on-site applications. Combination of pre-treating upflow anaerobic sludge blanket (UASB) -septic tank and MBBR removed over 92% of CODt, 99% of biological oxygen demand (BOD7), and 65-70% of nitrogen. PMID:16647521

  18. Nitrogen removal and heavy metals in leachate treatment using SBR technology

    International Nuclear Information System (INIS)

    Biological nitrogen removal by the use of Sequencing Batch Reactors (SBRs) is today an accepted and well proven model. The results of SBR performance on nitrogen removal have encouraged consultants, engineering companies and landfill operators to develop and build full scale SBR plants at a number of sites in Sweden. Two of these plants, Isaetra and Norsa, have been studied closely. The Norsa plant treats leachate at a controlled water temperature, while the Isaetra plant is exposed to temperature variation throughout the year. Both plants have very well proven nitrogen removal capacities, although winter conditions have an adverse impact on their performance. Typical nitrification efficiency is close to 100%, while the total nitrogen removal is about 90-95% under stable operation conditions. A good relationship between the nitrogen load and the nitrification rate has been observed at the Norsa SBR plant. The heavy metal content in the leachate is very low thanks to anaerobic precipitation inside the landfill into metal sulphides. The heavy metal content in the biological sludge is consequently also very low.

  19. Operational strategies for nitrogen removal in granular sequencing batch reactor

    International Nuclear Information System (INIS)

    This study investigated the effects of different operational strategies for nitrogen removal by aerobic granules with mean granule sizes of 1.5 mm and 0.7 mm in a sequencing batch reactor (SBR). With an alternating anoxic/oxic (AO) operation mode without control of dissolve oxygen (DO), the granular sludge with different size achieved the total inorganic nitrogen (TIN) removal efficiencies of 67.8-71.5%. While under the AO condition with DO controlled at 2 mg/l at the oxic phase, the TIN removal efficiency was improved up to 75.0-80.4%. A novel operational strategy of alternating anoxic/oxic combined with the step-feeding mode was developed for nitrogen removal by aerobic granules. It was found that nitrogen removal efficiencies could be further improved to 93.0-95.9% with the novel strategy. Obviously, the alternating anoxic/oxic strategy combined with step-feeding is the optimal way for TIN removal by granular sludge, which is independent of granule size.

  20. Enhanced biological phosphorus removal employing EDTA disodium

    Energy Technology Data Exchange (ETDEWEB)

    Bojinova, D.; Velkova, R. [Higher Inst. of Chemical Technology, Sofia (Bulgaria)

    1996-12-31

    The biological phosphorus removal is a promising alternative to the conventional chemical technologies for processing of phosphate raw materials. The object of this study was the effect of EDTA disodium on the biotreatment of tunisian phosphorite with the strain of Aspergillus niger. The incubation was carried out in two nutritive mediums, with different phosphate content. The experimental results showed that the additives of EDTA disodium in the nutritive medium increased the rate of extraction of P{sub 2}O{sub 5} and shortened significantly the time for biological leaching. 5 refs., 3 figs., 2 tabs.

  1. Ammonia, nitrite and nitrate nitrogen removal from polluted source water with ozonation and BAC processes

    International Nuclear Information System (INIS)

    Studies on the removal of ammonia-, nitrite-, and nitrate nitrogen with ozonation (O3), sand filtration (SF), biological activated carbon (BAC), SF-BAC, and/or O3-BAC processes were carried out in two pilot plants and a full scale plant, respectively. The results showed that all of the tested processes exhibited certain nitrogen removal efficiencies, of which both the O3-SF-BAC and O3-BAC processes were most effective and efficient in removing ammonia nitrogen, with mean removal efficiencies of some 90 and 80 percent, respectively. Ozonation was found able to oxidize some organic nitrogen into ammonia, and nitrite ion into nitrate ion. It was also found out, with interest, that the O3-BAC process can carry the nitrification process to the end under sufficient DO content, as well as more hydrocarbon substrates through ozonation that are more easily assimilated by some strains of nitrobacter that can multiply heterotrophically in its carbon beds. In the BAC process, both the DO and easily assimilated substrate contents were too low in its carbon beds due to no ozonation to sustain nitrobacter growth; but the nitrite conversion bacteria, like nitrosomas, can survive under such conditions. As a result, nitrite or nitrate ion content increased multiply in the effluents from BAC or O3-BAC processes over their influents, respectively. The removal mechanisms of various processes for the three forms of nitrogen were studied and discussed, and the optimum design parameters were determined as well

  2. A/A/O工艺脱氮除磷运行效果分析%Analysis on running effect for biological nitrogen and phosphorus removal of A/A/O technology

    Institute of Scientific and Technical Information of China (English)

    李曈; 郝瑞霞; 刘峰; 刘京

    2011-01-01

    为提高城市污水处理厂科学运行管理水平和出水质量,通过对某污水处理厂污水处理工艺的沿程采样分析,对比分析了A/A/O工艺脱氮除磷效果与工艺运行控制参数之间的相关关系。结果表明,A/A/O工艺对总氮去除率为83.2%,出水中氮的形态主要为硝酸盐氮;出水中总磷浓度基本达到一级A标准,总磷去除率在86.3%以上;缺氧段具有明显的反硝化聚磷作用;脱氮除磷效果与污泥负荷有反向变化关系,泥龄对磷的去除效果影响明显,当污泥负荷控制在0.15kg BOD5/(kg MLVSS.d)左右,泥龄控制在10~12 d时,可以同时%In order to improve the scientific management level and effluent quality of a municipal wastewater treatment plant(WWTP),the relationship between nitrogen and phosphorus removal effect and operating parameters of the A/A/O technology was studied by sampling and analyzing along the process in WWTP of Beijing.The results showed that the total nitrogen removal rate was 83.2%,and the main form of nitrogen was nitrate nitrogen in effluent.The TP concentration in effluent could reach the 1 grade A level of national discharging standard in China basically,and the TP removal rate was over 86.3%.The denitrifying phosphorus removal played a remarkable role in the anoxic phase of A/A/O process.The relationship between nitrogen and phosphorus removal effect and sludge loading expressed inverse variation.Sludge retain time(SRT) had an obvious impact on phosphorus removal.When the sludge loading was about 0.15 kg BOD5/(kg MLVSS·d)and the SRT was about 10~12 d in A/A/O process,nitrogen and phosphorus removal rates were up to 81% and 88%,respectively.There was an inverse variation relationship between the phosphorus accumulation and the sludge emission capacities in the wastewater treatment system.When the sludge emission capacities maintained about 2~2.5 percent of influent,phosphorus removal can be controlled in the stable and

  3. Method for removal of nitrogen oxides from stationary combustion sources

    Science.gov (United States)

    Cooper, Charles D. (Inventor); Clausen, III, Christian A. (Inventor); Collins, Michelle M. (Inventor)

    2004-01-01

    A method for removing NO.sub.X from gas streams emanating from stationary combustion sources and manufacturing plants utilizes the injection of hydrogen peroxide into the gas stream for rapid gas-phase oxidation of NO to NO.sub.2 and water-soluble nitrogen acids HNO.sub.2 and HNO.sub.3. The nitrogen acids may be removed from the oxidized gas stream by wet scrubbing or by contact with a particulate alkaline material to form a nitrite/nitrate salt.

  4. Simultaneous nitrogen, phosphorous, and hardness removal from reverse osmosis concentrate by microalgae cultivation.

    Science.gov (United States)

    Wang, Xiao-Xiong; Wu, Yin-Hu; Zhang, Tian-Yuan; Xu, Xue-Qiao; Dao, Guo-Hua; Hu, Hong-Ying

    2016-05-01

    While reverse osmosis (RO) is a promising technology for wastewater reclamation, RO concentrate (ROC) treatment and disposal are important issues to consider. Conventional chemical and physical treatment methods for ROC present certain limitations, such as relatively low nitrogen and phosphorus removal efficiencies as well as the requirement of an extra process for hardness removal. This study proposes a novel biological approach for simultaneous removal of nitrogen, phosphorus, and calcium (Ca(2+)) and magnesium (Mg(2+)) ions from the ROC of municipal wastewater treatment plants by microalgal cultivation and algal biomass production. Two microalgae strains, Chlorella sp. ZTY4 and Scenedesmus sp. LX1, were used for batch cultivation of 14-16 days. Both strains grew well in ROC with average biomass production of 318.7 mg/L and lipid contents up to 30.6%, and nitrogen and phosphorus could be effectively removed with efficiencies of up to 89.8% and 92.7%, respectively. Approximately 55.9%-83.7% Ca(2+) could be removed from the system using the cultured strains. Mg(2+) removal began when Ca(2+) precipitation ceased, and the removal efficiency of the ion could reach up to 56.0%. The most decisive factor influencing Ca(2+) and Mg(2+) removal was chemical precipitation with increases in pH caused by algal growth. The results of this study provide a new biological approach for removing nitrogen, phosphorous, and hardness from ROC. The results suggest that microalgal cultivation presents new opportunities for applying an algal process to ROC treatment. The proposed approach serves dual purposes of nutrient and hardness reduction and production of lipid rich micro-algal biomass. PMID:26954575

  5. Combination process of limited filamentous bulking and nitrogen removal via nitrite for enhancing nitrogen removal and reducing aeration requirements.

    Science.gov (United States)

    Guo, Jianhua; Peng, Yongzhen; Yang, Xiong; Gao, Chundi; Wang, Shuying

    2013-03-01

    Limited filamentous bulking (LFB) activated sludge process was proposed by Guo et al. (2010) to increase the removal of tiny suspended particulates in the clarifier and reduce aeration energy consumption. However, when the use of LFB process, ammonium removal efficiency would be compromised due to low dissolved oxygen (DO). In this study, the combination process of nitrogen removal via nitrite and LFB was achieved to enhance nitrogen removal and reduce aeration energy consumption by controlling low DO levels (0.5-1.0 mg L(-1)) in a lab-scale anoxic-oxic reactor (V=66 L) treating real domestic wastewater at room temperature. Above 85% of nitrite accumulation ratio was steadily maintained during continuous operation period. The combined process improved the total nitrogen (TN) removal by about 20% in comparison to the traditional process via the nitrate pathway, and also reduced the specific aeration energy consumption by 35%. COD, ammonium and TN removal efficiencies were up to 86%, 94% and 75%, respectively. The process proved effective in achieving a steady LFB state, whereby sludge volume index between 150 and 250 mL g(-1) was sustained for long-term operation. The microbial community structure was analyzed by fluorescence in situ hybridization, which indicated ammonia-oxidizing bacteria out-competed nitrite-oxidizing bacteria. Moreover, the filaments Type 0041 and Microthrix parvicella proliferated with limited abundance. The results indicated the combination process of LFB and nitrogen removal via nitrite under low DO was a feasible solution for saving energy and enhancing nitrogen removal when treating domestic wastewater. PMID:23305749

  6. Emissão de óxido nitroso nos processos de remoção biológica de nitrogênio de efluentes Nitrous oxide emission in the biological nitrogen removal process

    Directory of Open Access Journals (Sweden)

    Marcelo Bortoli

    2012-03-01

    Full Text Available O óxido nitroso (N2O é altamente impactante ao meio ambiente por ser um dos três gases mais importantes quando considerado o alto potencial de efeito estufa e a baixa quantidade emitida para a atmosfera. A preocupação com a geração de N2O no tratamento de efluentes tem crescido nas duas últimas décadas. Muitos estudos vêm sendo realizados com o objetivo de avaliar as condições de geração e emissão de N2O em etapas de remoção de nitrogênio no tratamento, tanto em escala laboratorial quanto em estações de tratamento de efluentes. Essas pesquisas demonstram que, sob certas condições, ambos os processos podem produzir e emitir grandes quantidades de N2O para a atmosfera, o que remete à importância de mais investigações para determinar as condições específicas que minimizem a produção e a emissão de N2O nesse caso.The nitrous oxide (N2O has a high striking power in environmental. It's one of the three most important greenhouse gases, when considered the greenhouse potential and emissions to the atmosphere. The concern in the two last decades with the N2O generation in wastewater treatment has grown. Many studies have been conducted with the objective of evaluate the conditions of N2O generation and emission in the nitrification and denitrification process, in biological nitrogen removal of wastewater treatment, both lab scale and wastewater treatment plants (WWTP. These studies show that under certain conditions, both processes can generate and emit large amounts of N2O to the atmosphere, what demonstrates the importance of conducting further investigations to determine specific conditions that minimize N2O production and emission.

  7. Direct Detection by In Situ PCR of the amoA Gene in Biofilm Resulting from a Nitrogen Removal Process

    OpenAIRE

    Hoshino, Tatsuhiko; Noda, Naohiro; Tsuneda, Satoshi; Hirata, Akira; Inamori, Yuhei

    2001-01-01

    Ammonia oxidation is a rate-limiting step in the biological removal of nitrogen from wastewater. Analysis of microbial communities possessing the amoA gene, which is a small subunit of the gene encoding ammonia monooxygenase, is important for controlling nitrogen removal. In this study, the amoA gene present in Nitrosomonas europaea cells in a pure culture and biofilms in a nitrifying reactor was amplified by in situ PCR. In this procedure, fixed cells were permeabilized with lysozyme and sub...

  8. USE OF ARTIFICIAL WETLANDS TO REMOVE NITROGEN FROM WASTEWATER

    Science.gov (United States)

    Studies of artificial wetlands at Santee, California, focused on nitrogen removal from municipal wastewaters using lower-cost alternatives to methanol to supply carbon to drive denitrification. Using plant biomass, mulched and applied to the surface of the artificial marsh beds, ...

  9. Municipal wastewater treatment for effective removal of organic matter and nitrogen

    International Nuclear Information System (INIS)

    The organic matter, as well as nitrogen and phosphorus, are nutrient substances. Their excess concentrations in water receiving bodies lead to eutrophication, moreover, the nitrogen content in water bodies is standardized according the sanitary-toxicological criterion of harmfulness: NH4+-N ≤0,39-2,0 mgl-, NO3-N ≤9,1-10 mgl-. The municipal wastewater contain, usually, organic matter estimated by BOD 150-200 mgl-, and COD 300-400 mgl-, the nitrogen compounds 50-60 mgl-, and NH4+-N 20-25 mgl-. NOx-N are practically absent. Their presence indicated on discharge of industrial wastewater. The total phosphorus is present in the concentration of 15 mgl-, PO4- - P 5-8 mgl-. Activated sludge process has been most widely used in the USSR for municipal wastewater treatment. The activated sludge is biocenoses of heterotrophic and auto trophic microorganisms. They consume nutrient matters, transferring pollution of wastewater by means of enzyme systems in acceptable forms. C, N and P-containing matters are removed from wastewater by biological intake for cell synthesis. Moreover C- containing matters are removed by oxidation to CO2 and H2O. P-containing compounds under definite conditions associate with solid fraction of activated sludge and thus simultaneously removed from wastewater. The removal of nitrogen in addition to biosynthesis is carried out only in the denitrification process, when oxygen of NOx-N is used for oxidation of organic matter and produced gaseous nitrogen escapes into the atmosphere

  10. Nitrogen supply of crops by biological nitrogen fixation. 2

    International Nuclear Information System (INIS)

    In the present work the contributions from combined N-sources and symbiotic nitrogen fixation to the nitrogen supply of field-grown peas and field beans were evaluated by means of 15N fertilizer dilution. The effect of N-fertilizer, supplied at sowing and at different stages of plant development, on nitrogen fixation, yield and protein production in peas, was studied in pot experiments. (author)

  11. Nitrogen removal from concentrated latex wastewater by land treatment

    Directory of Open Access Journals (Sweden)

    Vikanda Thongnuekhang

    2004-05-01

    Full Text Available Most of the concentrated latex factories in the South of Thailand discharge treated wastewater that contains high level of nitrogen to a nearby river or canals leading to a water pollution problem. A study of land treatment system was conducted to treat and utilize nitrogen in treated wastewater from the concentrated latex factory. The experimental pilot-scale land treatment system was constructed at the Faculty of Engineering, Prince of Songkla University, Hat Yai Campus. It consisted of water convolvulus (Ipomea aquatica, I. Reptans, tropical carpet grass (Axonopus compresus (Swartz Beav. and control unit (no plantation. The treated wastewater from the stabilization pond system of the selected concentrated latex factoryin Songkhla was used to irrigate each experimental unit. Influent and effluent from the experimental units were analyzed for TKN, NH3-N, Org-N, NO3 --N, NO2 --N, BOD5, sulfate, pH and EC. The land treatment system resulted a high removal efficiency for nitrogen. Tropical carpet grass provided higher removal efficiency than other units for all parameters. The removal efficiency of water convolvulus and control unit were not significantly different. The average removal efficiency of TKN, NH3-N, Org-N, BOD5 and sulfate for tropical carpet grass unit were 92, 97, 61, 88 and 52%, for water convolvulus unit were 75, 80, 43, 41 and 30%, and for control unit were 74, 80, 41, 31 and 28%, respectively. Mass balance of nitrogen transformation was conducted. It revealed that plant uptake was the major mechanism for nitrogen removal in land treatment.

  12. Biological nutrient removal in a sequencing batch reactor operated as oxic/anoxic/extended-idle regime.

    Science.gov (United States)

    Li, Xiao-ming; Chen, Hong-bo; Yang, Qi; Wang, Dong-bo; Luo, Kun; Zeng, Guang-ming

    2014-06-01

    Previous researches have demonstrated that biological phosphorus removal from wastewater could be induced by oxic/extended-idle (O/EI) regime. In this study, an anoxic period was introduced after the aeration to realize biological nutrient removal. High nitrite accumulation ratio and polyhydroxyalkanoates biosynthesis were obtained in the aeration and biological nutrient removal could be well achieved in oxic/anoxic/extended-idle (O/A/EI) regime for the wastewater used. In addition, nitrogen and phosphorus removal performance in O/A/EI regime was compared with that in conventional anaerobic/anoxic/aerobic (A(2)/O) and O/EI processes. The results showed that O/A/EI regime exhibited higher nitrogen and phosphorus removal than A(2)/O and O/EI processes. More ammonium oxidizing bacteria and polyphosphate accumulating organisms and less glycogen accumulating organisms containing in the biomass might be the principal reason for the better nitrogen and phosphorus removal in O/A/EI regime. Furthermore, biological nutrient removal with O/A/EI regime was demonstrated with municipal wastewater. The average TN, SOP and COD removal efficiencies were 93%, 95% and 87%, respectively. PMID:24393562

  13. Enhanced Biological Phosphorus Removal: Metabolic Insights and Salinity Effects

    OpenAIRE

    Welles, L.

    2015-01-01

    Enhanced biological phosphorus removal (EBPR) is a biological process for efficient phosphate removal from wastewaters through intracellular storage of polyphosphate by polyphosphate-accumulating organisms (PAO) and subsequent removal of PAO from the system through wastage of sludge. In comparison to physical and chemical phosphorus removal processes, the biological process has several advantages such as high removal efficiency, low cost, and no chemical sludge production, but disturbances an...

  14. Benchmarking biological nutrient removal in wastewater treatment plants: influence of mathematical model assumptions

    DEFF Research Database (Denmark)

    Flores-Alsina, Xavier; Gernaey, Krist V.; Jeppsson, Ulf

    2012-01-01

    This paper examines the effect of different model assumptions when describing biological nutrient removal (BNR) by the activated sludge models (ASM) 1, 2d & 3. The performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) benchmark wastewater treatment plant...... reactive settler: (1) increases the hydrolysis of particulates; (2) increases the overall plant's denitrification efficiency by reducing the SNOx concentration at the bottom of the clarifier; (3) increases the oxidation of COD compounds; (4) increases XOHO and XANO decay; and, finally, (5) increases the...

  15. Nitrogen and phosphorus removal in an airlift intermittent circulation membrane bioreactor.

    Science.gov (United States)

    Guo, Haiyan; Chen, Jiandong; Li, Yun; Feng, Tengteng; Zhang, Shoutong

    2013-12-01

    A new airlift intermittent circulation integrated bioreactor was developed for simultaneous nitrogen and phosphorus removal of wastewater, in which, circulation of mixed liquid between mixing zone and aeration zone was realized by aeration power, alternately anaerobic/anoxic bio-environment in mixing zone was realized by intermittent circulation and simultaneous nitrogen and phosphorus removal was obtained through strengthened denitrifying phosphorus removal process. Removal performance of the reactor was investigated and pollutant removal and transfer mechanism in one operation circle was analyzed. The experiment results indicated that under the influent condition of chemical oxygen demand (COD) concentration of 642.1 mg/L, total nitrogen (TN) of 87.4 mg/L and PO4(3-)-P of 12.1 mg/L, average removal efficiencies of COD, TN and PO4(3-)-P reached 96.4%, 83.2% and 90.5%, respectively, with the hydraulic residence time of 22 hr and operation circle time of 185 min. Track studies indicated that the separation of aeration and mixing zones and intermittent circulation of mixed liquid between the two zones provided distinct biological environments spatially and temporally, which ensured the occurrence of multifunctional microbial reactions. PMID:25078818

  16. [Removal of nitrogen in simulated rivers embanked by ecological concrete].

    Science.gov (United States)

    Chen, Yang-hui; Lü, Xi-wu; Wu, Yi-feng

    2008-08-01

    The removal of nitrogen was studied in four types of pilot-scale rivers. The embankment for rivers No. 1, 2 and 3 consisted of respectively spheriform ecological-concrete prefab-bricks, rectangular ecological-concrete prefab-bricks and square ecological-concrete prefab-bricks with 4 hemispheroids. The embankment for river No. 4 was made of concrete C25. The results show that the removal rates of NH4+ -N, NO2- -N, NO3- -N and TN of river 1 are 83.6%, 75.2%, 37.1% and 47.5% under hydraulic retention time of 2 days, 83.4%, 53.0%, 30.6% and 40.4% for river 2, 88.1%, 72.4%, 33.0% and 40.9% for river 3. Under the same condition, NH4+ -N, TN of river 4 decreasesby 61.1%, 9.1%, while NO2- -N, NO3- -N increase by 7.4%, 3.4% due to the transformation of NH4+ -N. It indicates that ecological embankment rivers can effectively remove nitrogen. Besides, the addition of pore rate in embankment structure and more rate of plant coverage are good for the removal of nitrogen in ecological embankment rivers. PMID:18839568

  17. Fuzzy Control of Nitrate Recirculation and External Carbon Addition in A/O Nitrogen Removal Process

    Institute of Scientific and Technical Information of China (English)

    马勇; 彭永臻; 王淑莹; 王晓莲

    2005-01-01

    Nitrogen and phosphorous concentrations of effluent water must be taken into account for the design and operation of wastewater treatment plants. In addition, the requirement for effluent quality is becoming strict.Therefore, intelligent control approaches are recently required in removing biological nutrient. In this study, fuzzy control has been successfully applied to improve the nitrogen removal. Experimental results showed that a close relationship between nitrate concentration and oxidation-reduction potential (ORP) at the end of anoxic zone was found for anoxic/oxic (A/O) nitrogen removal process treating synthetic wastewater. ORP can be used as online fuzzy control parazneter of nitrate recirculation and external carbon addition. The established fuzzy logic controller that includes two inputs and one output can maintain ORP value at-86 mV and -90 mV by adjusting the nitrate recirculation flow and external carbon dosage respectively to realize the optimal control of nitrogen removal, improving the effluent quality and reducing the operating cost.

  18. Nitrogen removal via nitrite from municipal landfill leachate

    Institute of Scientific and Technical Information of China (English)

    WU Lina; PENG Chengyao; ZHANG Shujun; PENG Yongzhen

    2009-01-01

    A system consisting of a two-stage up-flow anaerobic sludge blanket (UASB),an anoxic/aerobic (A/O) reactor and a sequencing batch reactor (SBR),was used to treat landfill leachate.During operation,denitrification and methanogenesis took place simultaneously in the first stage UASB (UASB1),and the effluent chemical oxygen demand (COD) was further removed in the second stage UASB (UASB2).Then the denitrification of nitrite and nitrate in the returned sludge by using the residual COD was accomplished in the A/O reactor,and ammonia was removed via nitrite in it.Last but not least,the residual ammonia was removed in SBR as well as nitrite and nitrate which were produced by nitrification.A system consisting of a two-stage UASB and an A/O reactor was used to achieve the stable short-cut nitrification in the first stage (60 d).The effluent of stage one was treated by SBR in the second stage (60 d).The results over 120 d were as follows: when the total nitrogen (TN) concentration of influent leachate was about 2500 mg/L and the ammonia nitrogen concentration was about 2000 mg/L,the short-cut nitrification with 85%-90% nitrite accumulation was achieved stably in the A/O reactor.The TN and ammonia nitrogen removal efficiencies of the system were 98% and 97%,respectively.The residual ammonia,nitrite and nitrate which were produced by nitrification in the A/O reactor could be washed out almost completely in SBR.The TN and ammonia nitrogen concentrations of final effluent were about 39 mg/L and 12 mg/L,respectively.

  19. Performance of an autotrophic nitrogen removing reactor: Diagnosis through fuzzy logic

    DEFF Research Database (Denmark)

    Vangsgaard, Anna Katrine; Mauricio Iglesias, Miguel; Mutlu, Ayten Gizem; Gernaey, Krist; Smets, Barth F.; Sin, Gürkan

    Autotrophic nitrogen removal through nitritation-anammox in one stage SBRs is an energy and cost efficient alternative to conventional treatment methods. Intensification of an already complex biological system challenges our ability to observe, understand, diagnose, and control the system. A fuzzy...... logic diagnosis tool was developed, utilizing stoichiometric and concentration ratio measurements and removal efficiencies, along with rules derived from process knowledge. The tool could accurately determine the overall performance of the system and can therefore serve as a powerful tool to provide...

  20. A Modified Oxidation Ditch with Additional Internal Anoxic Zones for Enhanced Biological Nutrient Removal

    Institute of Scientific and Technical Information of China (English)

    LIU Wei; YANG Dianhai; XU Li; SHEN Changming

    2013-01-01

    A novel modified pilot scale anaerobic oxidation ditch with additional internal anoxic zones was operated experimentally,aiming to study the improvement of biological nitrogen and phosphorus removal and the effect of enhanced denitrifying phosphorus removal in the process.Under all experimental conditions,the anaerobic-oxidation ditch with additional internal anoxic zones and an internal recycle ratio of 200% had the highest nutrient removal efficiency.The effluent NH+4-N,total nitrogen(TN),PO34--P and total phosphorus(TP)contents were 1.2 mg·L-1,13 mg·L-1,0.3 mg·L-1 and 0.4 mg·L-1,respectively,all met the discharge standards in China.The TN and TP removal efficiencies were remarkably improved from 37% and 50% to 65% and 88% with the presence of additional internal anoxic zones and internal recycle ratio of 200%.The results indicated that additional internal anoxic zones can optimize the utilization of available carbon source from the anaerobic outflow for denitrification.It was also found that phosphorus removal via the denitrification process was stimulated in the additional internal anoxic zones,which was beneficial for biological nitrogen and phosphorus removal when treating wastewater with a limited carbon source.However,an excess internal recycle would cause nitrite to accumulate in the system.This seems to be harmful to biological phosphorus removal.

  1. Enhanced biological phosphorus removal from activated sludge system; Eliminacion biologica del fosfor en aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Pidre Bocardo, J. R.; Toja Santillana, J.; Alonso Alvarez, E. [Sevilla (Spain)

    1999-06-01

    A literature review of enhanced biological phosphorus removal was performed. This biological removal is based on the selective enrichment of bacteria accumulating inorganic polyphosphate, obtained at a cyclic regime of alternating anaerobic and aerobic conditions; or anaerobic, anoxic and aerobic zones for combined nitrogen and phosphorus removal. Some bacterial groups may to be implicate in this process, the gen Acinetobacter has been the most studied. In this paper a study of phosphorate forms from wastewater for a conventional activated sludge system is presented. (Author) 40 refs.

  2. Stormwater nitrogen removal performance of a floating treatment wetland.

    Science.gov (United States)

    Borne, Karine E; Tanner, Chris C; Fassman-Beck, Elizabeth A

    2013-01-01

    The nitrogen (N) removal efficiency and effluent quality of two parallel stormwater retention ponds, one retrofitted with a floating treatment wetland (FTW) and one without any vegetation, was compared in a field trial. This study shows that inclusion of FTWs in stormwater retention ponds has potential to moderately improve N removal. Median FTW outlet event mean concentrations (EMCs) were lower than median inlet and control pond outlet EMCs for all species of N, except for NH(4)-N. Performance was statistically better from late spring to end autumn due to higher organic nitrogen (ON) removal and denitrification in presence of the FTW. Low dissolved oxygen (DO), higher temperature and increased organic matter (OM) and microbial activity below the FTW, likely facilitated the higher denitrification rates observed over this period. Greater sediment N accumulation in the FTW pond also contributed to its higher overall N removal. Higher OM availability in the FTW pond due to release of root exudates and supply of detritus from plant die-back may have contributed to floc formation in the water column, increasing particulate ON settlement. Enhanced ON mineralisation may also be responsible but was probably limited in summer due to the low DO induced by the FTW. Direct uptake by the plants appears to be of less importance. PMID:24135117

  3. Denitrification in an anoxic rotating biological contactor under two carbon/nitrogen ratios

    OpenAIRE

    Cortez, Susana; Teixeira, P; Oliveira, Rosário; Mota, M.

    2008-01-01

    The aim of the present work was to compare the performance of an anoxic bench-scale rotating biological contactor (RBC), in terms of the denitrification process, applied to treat synthetic wastewater under two carbon/nitrogen (C/N) molar ratios (1.5 and 3). The average removal efficiency in terms of nitrogen-nitrate was of about 90.4% at a C/N=1.5 lowering to 73.7% at a C/N=3. Considering carbon-acetate removal an overall efficiency of 82.0% and 63.6% was attained at a C/N rati...

  4. Studies on Nitrogen Oxides Removal Using Plasma Assisted Catalytic Reactor

    Institute of Scientific and Technical Information of China (English)

    V. Ravi; Young Sun Mok; B. S. Rajanikanth; Ho-Chul Kang

    2003-01-01

    An electric discharge plasma reactor combined with a catalytic reactor was studied for removing nitrogen oxides. To understand the combined process thoroughly, discharge plasma and catalytic process were separately studied first, and then the two processes were combined for the study. The plasma reactor was able to oxidize NO to NO2 well although the oxidation rate decreased with temperature. The plasma reactor alone did not reduce the NOx (NO+NO2)level effectively, but the increase in the ratio of NO2 to NO as a result of plasma discharge led to the enhancement of NOx removal efficiency even at lower temperatures over the catalyst surface (V2O5-WOa/TiO2). At a gas temperature of 100℃, the NOx removal efficiency obtained using the combined plasma catalytic process was 88% for an energy input of 36 eV/molecule or 30 J/1.

  5. Alternate anoxic/aerobic operation for nitrogen removal in a membrane bioreactor for municipal wastewater treatment.

    Science.gov (United States)

    Guglielmi, G; Andreottola, G

    2011-01-01

    A large pilot-scale membrane bioreactor (MBR) with a conventional denitrification/nitrification scheme for municipal wastewater treatment has been run for one year under two different aeration strategies in the oxidation/nitrification compartment. During the first five months air supply was provided according to the dissolved-oxygen set-point and the system run as a conventional predenitrification MBR; then, an intermittent aeration strategy based on effluent ammonia nitrogen was adopted in the aerobic compartment in order to assess the impact on process performances in terms of N and P removal, energy consumption and sludge reduction. The experimental inferences show a significant improvement of the effluent quality as COD and total nitrogen, both due to a better utilization of the denitrification potential which is a function of the available electron donor (biodegradable COD) and electron acceptor (nitric nitrogen); particularly, nitrogen removal increased from 67% to 75%. At the same time, a more effective biological phosphorus removal was observed as a consequence of better selection of denitrifying phosphorus accumulating organisms (dPAO). The longer duration of anoxic phases also reflected in a lower excess sludge production (12% decrease) compared with the standard pre-denitrification operation and in a decrease of energy consumption for oxygen supply (about 50%). PMID:22335118

  6. Biological anoxic phosphorus removal in a continuous-flow external nitrification activated sludge system

    Energy Technology Data Exchange (ETDEWEB)

    Kapagiannidis, A. G.; Aivasidis, A.

    2009-07-01

    Application of Biological Nutrient Removal (BNR) process in wastewater treatment is necessitated for the protection of water bodies from eutrophication. an alternative BNR method is tested for simultaneous Carbon (C), Nitrogen (N) and Phosphorus (P) removal in a continuous-flow bench scale plant for municipal wastewater treatment. The plant operation is based on the activity of two microbial populations which grow under different operational conditions (two sludge system). (Author)

  7. Removal of nitrogen from wastewater with perennial ryegrass/artificial aquatic mats biofilm combined system

    Institute of Scientific and Technical Information of China (English)

    Chongjun Chen; Rui Zhang; Liang Wang; Weixiang Wu; Yingxu Chen

    2013-01-01

    To develop a cost-effective combined phytoremediation and biological process,a combined perennial ryegrass/artificial aquatic mat biofilm reactor was used to treat synthetic wastewater.Influent ammonium loading,reflux ratio,hydraulic retention time (HRT) and temperature all had significant effects on the treatment efficiency.The results indicated that the effluent concentration of ammonium increased with increasing influent ammonium loading.The reactor temperature played an important role in the nitrification process.The ammonium removal efficiency significantly decreased from 80% to 30%-50% when the reactor temperature dropped to below 10℃.In addition,the optimal nitrogen removal condition was a reflux ratio of 2.The nitrate and ammonium concentration of the effluent were consistent with the HRT of the combined system.The chemical oxygen demand (COD) removal efficiency was at a high level during the whole experiment,being almost 80% after the start-up,and then mostly above 90%.The direct uptake of N by the perennial ryegrass accounted for 18.17% of the total N removal by the whole system.The perennial ryegrass absorption was a significant contributor to nitrogen removal in the combined system.The result-illustrated that the combined perennial ryegrass/artificial aquatic mat biofilm reactor demonstrated good performance in ammonium,total N and COD removal.

  8. Expert systems guide biological phosphorus removal

    Energy Technology Data Exchange (ETDEWEB)

    Krichten, D.J.; Wilson, K.D.; Tracy, K.D. (Air Products and Chemicals, Inc., Allentown, PA (United States))

    1991-10-01

    There is a large body of knowledge regarding optimum control strategies for new secondary wastewater treatment technology using an anaerobic selector to provide biological phosphorus removal. However, because the selector technology is new and the concepts differ somewhat from those used in conventional activated sludge wastewater treatment, a method of communicating this knowledge to plant operators is needed. Traditional methods such as classroom training and operating manuals are of limited effectiveness. The commonplace availability and low cost of the personal computer (PC) makes it practical to use a computer program to communicate the type of information required to control a wastewater treatment plant. Knowledge-based systems technology, commonly referred to as expert systems (ES) technology, is easy to use, provides useful information regarding a consistent control strategy, relieves the anxiety associated with learning a new process,' and provides instruction for inexperienced personnel. ES technology does not require special formatted input and is therefore easily accessible. All information required by the program is readily available through routine laboratory analysis, common plant instrumentation, or direct user observation. The program was designed for all levels of computer users and will run on all IBM-compatible or Apple MacIntosh systems.

  9. Possibility in optimization of biological phosphorus removal

    Energy Technology Data Exchange (ETDEWEB)

    Schoenberger, R.

    1989-02-01

    The elimination-efficiency of wastewater treatment plants with biological phosphorus removal is often limited by the following aspects: Low concentrations of organic acids in influent wastewater, hydraulic- and load fluctuations, low anaerobic sludge detention time, transfer of nitrate into the anaerobic zone, phosphorus release in the final clarifier and in sludge treatment units, high effluent suspended solids content. In this context, the following optimization measures seem to be advantageous: 'Activated primary tanks' and 'activated sludge thickeners' are adequate techniques to raise the concentration of organic acids in the wastewater by pre-acidification. Simultaneous acidification takes place in an anaerobic sedimentation basin as realized in the EASC-process (extended anaerobic sludge contact). Below the sludge blanket of an EASC-sedimentation tank, anaerobic conditions can be maintained even in the case of nitrate input. Furthermore, this process is suitable to compensate load- and hydraulic fluctuations of wastewater. To avoid phosphorus release in the final clarifier, it is important to improve sludge settleability. If a low sludge blanket and/or high oxygen concentrations are maintained, phosphorus release in the final clarifier can be limited. Further reduction of total phosphorus is possible with filtration only. Measures against high return flow phosphorus loads are mechanical dewatering of excess sludge and chemical precipitation of digester supernatant.

  10. The Role of Molybdenum in Biological Nitrogen Fixation

    Directory of Open Access Journals (Sweden)

    Armiadi

    2009-09-01

    Full Text Available The availability of soil Molybdenum (Mo especially for acid soil is scarcely found, while their existency determines the process of Nitrogen fixation. Mo is the component of meta-protein nitrogenase which helps the process of biological nitrogen fixation and acts as essential component which needed for N bacteria metabolism. The nitrogenase enzyme needs Mo element in the process of its metabolism, which acts as electron carrier between oxidized and reduction stages. The deficiency of Mo has been reported in several crops, with various appearance, such as chlorosis or yellowish leaves. The paper describes the role of Mo in biological nitrogen fixation.

  11. Nitrogen and phosphorus removal under intermittent aeration conditions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A practice wastewater treatment plant was operated usingintermittent aeration activated sludge process to enhancebiological nitrogen and phosphorus removal. When the influentconcentrations of CODCr, BOD5, TN, TP, NH3-N, TKN, and SS varied ina range of 207.5-1640 mg/L, 61.8-637 mg/L, 28.5-75.6 mg/L, 4.38-20.2 mg/L, 13.6-31.9 mg/L, 28.5-75.6 mg/L, and 111-1208 mg/L, theeffluent means were less than 50 mg/L, 20 mg/L, 5 mg/L, 1.0 mg/L,5 mg/L, 10 mg/L, and 20 mg/L, respectively. Based on a long time ofoperating results, this process is very suitable for nutrientbiological removal for treating the municipal wastewater thosewater characteristics are similar as that of the Songjiang Municipal Waste water Treatment plant(SJMWTP).

  12. Investigation of the Effects of COD/TP Ratio on the Performance of a Biological Nutrient Removal System

    OpenAIRE

    Punrattanasin, Warangkana

    1997-01-01

    The laboratory-scale University of Cape Town (UCT) process was designed to investigate the effects of changing COD/TP ratios on the performance of biological nutrient removal (BNR) processes. Specific objectives of the research were to investigate the effects of COD/TP ratio on the rates of phosphorus removal, COD removal, nitrogen removal, PHB utilization and oxygen uptake. The system was fed with municipal wastewater and operated at 20° C. The influent COD concentration was held approximat...

  13. Effect of ammonia load on efficiency of nitrogen removal in an SBBR with liquid-phase circulation

    Directory of Open Access Journals (Sweden)

    C. S. A. Canto

    2008-06-01

    Full Text Available The removal of biological nitrogen from a synthetic wastewater with different ammonium nitrogen concentrations (50 and 100 mgN-NH4+/L by a nitrification and denitrification process using a sequencing batch biofilm reactor (SBBR with liquid-phase circulation was studied. The system with a total working volume of 4.6 L (3.7 L in the reactor and 0.9 L in the reservoir treated 2.1 L of synthetic wastewater in 12-h cycles. As inoculum two types of biomass were used: an anaerobic/anoxic one from an up-flow anaerobic sludge blanket reactor (UASB and an aerobic one from a prolonged aeration activated sludge system. The system, maintained at 30 ± 1 ºC, operated in batch mode followed by fed-batch mode and was aerated intermittently. During fed-batch operation the reactor was fed with an external carbon source as electron donor in the denitrifying step and with no aeration. When the reactor was fed with 50 mgN-NH4+/L, efficiencies of removal of ammonium nitrogen and total nitrogen from the effluent were 93.8 and 72.2%, respectively, and nitrite, nitrate and organic nitrogen concentrations were 0.07, 6.4 and 0.5 mg/L, respectively. On the other hand, when the influent ammonium nitrogen concentration was 100 mgN-NH4+/L, residual nitrite and nitrate were 0.17 and 20.4, respectively, and no N-Org was found in the effluent. It should be mentioned that residual nitrate remained unaltered at the different C/N ratios used. Consequently, efficiency of total nitrogen removal was reduced to 66.7%, despite efficiency of ammonium nitrogen removal exceeding 90%. These results show the potential of the proposed system in removing ammonium nitrogen from liquid effluents with a moderate ammonium nitrogen concentration.

  14. Removal of Nitrogen and Phosphorus From Reject Water Using Chlorella vulgaris Algae After Partial Nitrification/Anammox Process.

    Science.gov (United States)

    Gutwinski, Piotr; Cema, Grzegorz

    2016-01-01

    Wastewater containing nutrients like ammonia, nitrite, nitrate and phosphates have been identified as the main cause of eutrophication in natural waters. Therefore, a suitable treatment is needed. In classical biological processes, nitrogen and phosphorus removal is expensive, especially due to the lack of biodegradable carbon, thus new methods are investigated. In this paper, the new possibility of nitrogen and phosphorus removal in side stream after the partial nitrification/Anammox process is proposed. Research was carried out in a lab-scale vertical tubular photobioreactor (VTR) fed with real reject water, from dewatering of digested sludge, after partial nitrification/Anammox process from lab-scale sequencing batch reactor (SBR). Nitrogen and phosphorus concentrations were measured every three days. The average nitrogen and phosphorus loads were 0.0503 ± 0.036 g N g(vss)/d and 0.0389 ± 0.013 g P g(vss)/d accordingly. Results have shown that microalgae were able to efficiently remove nitrogen and phosphorus. The average nitrogen removal was 36.46% and phosphorus removal efficiency varied between 93 and 100%. PMID:26803028

  15. Nitrogen Removal Efficiency at Centralized Domestic Wastewater Treatment Plants in Bangkok, Thailand

    Directory of Open Access Journals (Sweden)

    Pongsak Noophan

    2009-07-01

    Full Text Available In this study, influents and effluents from centralized domestic wastewater treatment systems in Bangkok (Rattanakosin, Dindaeng, Chongnonsi, Nongkhaem, and Jatujak were randomly collected in order to measure organic nitrogen plus ammonium-nitrogen (total Kjeldahl nitrogen, total organic carbon, total suspended solids, and total volatile suspended solids by using Standard Methods for the Examination of Water and Wastewater 1998. Characteristics of influent and effluent (primary data of the centralized domestic wastewater treatment system from the Drainage and Sewerage Department of Bangkok Metropolitan Administration were used to analyze efficiency of systems. Fluorescent in situ hybridization (FISH was used to identify specific nitrifying bacteria (ammonium oxidizing bacteria specific for Nitrosomonas spp. and nitrite oxidizing bacteria specific for Nitrobacter spp. and Nitrospira spp.. Although Nitrosomonas spp. and Nitrobacter spp. were found, Nitrospira spp. was most prevalent in the aeration tank of centralized wastewater treatment systems. Almost all of the centralized domestic wastewater treatment plants in Bangkok are designed for activated sludge type biological nutrient removal (BNR. However, low efficiency nitrogen removal was found at centralized wastewater treatment plants in Bangkok. Influent ratio of TOC:N at centralized treatment plant is less than 2.5. Centralized wastewater treatment systems have not always been used suitability and used successfully in some areas of Bangkok Thailand.

  16. Elemental sulfur formation and nitrogen removal from wastewaters by autotrophic denitrifiers and anammox bacteria.

    Science.gov (United States)

    Liu, Chunshuang; Zhao, Dongfeng; Yan, Laihong; Wang, Aijie; Gu, Yingying; Lee, Duu-Jong

    2015-09-01

    Elemental sulfur (S(0)) formation from and nitrogen removal on sulfide, nitrate and ammonium-laden wastewaters were achieved by denitrifying ammonium oxidation (DEAMOX) reactor with autotrophic denitrifiers and anaerobic ammonium oxidation (anammox) bacteria. The sulfide to nitrate ratio is a key process parameter for excess accumulation of S(0) and a ratio of 1.31:1 is a proposed optimum. The Alishewanella, Thauera and Candidatus Anammoximicrobium present respectively the autotrophic denitrifiers and anammox bacteria for the reactor. DEAMOX is demonstrated promising biological process for treating organics-deficient (S+N) wastewaters with excess S(0) production. PMID:26022701

  17. Stoichiometric deduction of activated sludge process for organic carbon and nitrogen removal

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-yong; ZOU Lian-pei

    2009-01-01

    The activated sludge process (ASP) is the most generally applied biological wastewater treatment method. The ASP for the removal of organic carbon and nitrogen can be looked as the combination of eight processes. In order to set up an ASP model, the stoichiometric coefficients should be deduced so that the stoichiometric matrix can be presented. The important assumptions and simplifications behind the model for ASP are enumerated. Using the matrix, mass balance equation and consistent units, the stoichiometric coefficients in the eight processes are exclusively deduced one by one.

  18. Kinetics of nitrogen removal in high rate anammox upflow filter

    International Nuclear Information System (INIS)

    The process kinetics for laboratory-scale anammox (anaerobic ammonium oxidation) upflow filter using synthetic wastewater as feed were investigated. The experimental unit consisted of a 2.0 L reactor filled with three-dimensional plastic media. The filter was tested for different influent substrate concentrations and hydraulic retention time (HRT). The substrate loading removal rate was compared with prediction of Stover-Kincannon, second-order and the first-order substrate removal models. Upon approaching pseudo-steady-state condition, substrate ammonium or nitrite concentrations were increased from 280 to 462 mg N/L, while HRT was stepwise decreased from 14.4 to 2 h, with a concomitant increase in nitrogen loading rate (NLR) from 0.93 to 7.34 g/L day. Based on calculations, Stover-Kincannon model and second-order 'Grau' model were found to be the appropriate models to describe the upflow filter. According to Stover-Kincannon model, the maximum total substrate removal rate constant (Umax) and saturation value constant (KB) were suggested as 12.4 and 12.0 g N/L day, respectively. As Stover-Kincannon model and second-order model gave high correlation coefficients (97.9% and 98.6%, respectively), these models may be used in predicting the behavior or design of the anammox filter.

  19. Simultaneous phosphorus and nitrogen removal in a continuous-flow two-sludge system

    Institute of Scientific and Technical Information of China (English)

    LI Xiang-kun; HUANG Rong-xin; BAO Lin-lin; SHAO Chun-hong; ZHANG Jie

    2006-01-01

    The ability of simultaneous biological phosphorus and nitrogen removal was investigated in a lab-scale continuous-flow two-sludge system. Alternating anaerobic and anoxic conditions were combined with contact oxidation stage for treating raw municipal wastewater. Long-term experiments showed that the contradiction of competing for the organic substrate between denitrifying bacteria and PAOs (phosphorus accumulating organisms) in traditional phosphorus and nitrogen removal system has been resolved. The system can adapt to low influent COD/TN ratio (C/N). Furthermore the SRT (sludge retention time) of nitrifying sludge and denitrifying phosphorus removal sludge can be controlled at optimal conditions respectively. The removal efficiency of COD, TP,TN, and NH4-N was 81.78%, 92.51%, 75.75%, and 84.47% respectively. It was also found that the appropriate influent C/N should be controlled at the range of 3.8-6, while the optimal C/N to the system ranged between 4-5, and the BFR (bypass sludge flow rate)should be controlled at 0.35 around.

  20. Biological - Elwha River Dam Removal Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem...

  1. [Effective nitrogen removal in low C/N wastewater with combined aerobic-low DO biofilm treatment process].

    Science.gov (United States)

    Chen, Xiu-Rong; Ai, Qi-Feng; Xu, Wen-Lu; Wu, Min-Lin

    2011-10-01

    The municipal wastewater in China is characterized by low ratio of carbon to nitrogen, which is the key restrictive factor for effective biological removal of nitrogen. In this study, the aerobic-low DO biofilm process was used for the nitrogen removal of municipal wastewater. By means of adjusting inflow ratios of aerobic section to low-DO section, hydraulic retention time (HRT) and inflow ratio of carbon to nitrogen (C/N), the performances of nitrification in aerobic biofilm section and denitrification in low-DO section could be improved, the good performance of nitrogen removal was achieved. In order to insure the good effluent quality, especially for ammonia nitrogen and total nitrogen indexes, the nitrification and denitrification could be made up in aerobic and low-DO biofilm section respectively due to the coexistence of aerobic and anoxic zone in biofilm. There were 3 stages for the research process. In the first stage, the original C/N, inflow ratios of aerobic section to low-DO section were chosen as 3:1 and 1:1 respectively, then the effects of various HRT (aerobic section + low DO section) values such as (10 + 5) h, (8 + 4) h, (6 + 3) h, (4 + 2) h to nitrogen removal were analyzed. According to the conclusion in the first stage, the original C/N was kept at 3:1, HRT (aerobic section + low DO section) was (10 + 5) h. Then, the effects of various inflow ratios to nitrogen removal were studied in the second stage. In the third stage, when HRT(aerobic section + low DO section) was (10 + 5) h and inflow ratio was 1:1, the original C/N were adjusted from 2:1, 3:1, 5:1 to 10:1. To conclude, the optimal parameters for nitrogen removal in the biofilm system were as follows: original C/N = 5:1, inflow ratio of aerobic to low-DO section = 1:1, HRT of aerobic and low-DO sections were 10 h and 5 h respectively. As a result, COD, ammonia nitrogen and total nitrogen could be removed from 254 mg/L to 48 mg/L, 37.2 mg/L to 9.3 mg/L and 48.2 mg/L to 14.8 mg

  2. Nitrogen removal in a Sequencing Batch Biofilm Reactor : effect of carbon availability and intermittent aeration

    OpenAIRE

    Vieira, Maria Madalena Costa; Brito, A. G.; R. Nogueira

    2009-01-01

    This study aimed to investigate the effects of carbon availability and intermittent aeration on nitrogen removal in a Sequencing Batch Biofilm Reactor (SBBR). The percentage of nitrogen removal in the SBBRs operating with dump fill and slow fill with optimum intermittent aeration was quite similar, 75.7% and 69.2%, respectively, indicating that intermittent aeration allowed a considerable energy saving without compromising significantly nitrogen removal. Accumulation of stor...

  3. [Identification of a high ammonia nitrogen tolerant and heterotrophic nitrification-aerobic denitrification bacterial strain TN-14 and its nitrogen removal capabilities].

    Science.gov (United States)

    Xin, Xin; Yao, Li; Lu, Lei; Leng, Lu; Zhou, Ying-Qin; Guo, Jun-Yuan

    2014-10-01

    A new strain of high ammonia nitrogen tolerant and heterotrophic nitrification-aerobic denitrification bacterium TN-14 was isolated from the environment. Its physiological and biochemical characteristics and molecular identification, performences of heterotrophic nitrification-aerobic, the abilities of resistance to ammonia nitrogen as well as the decontamination abilities were studied, respectively. It was preliminary identified as Acinetobacter sp. according to its physiological and biochemical characteristics and molecular identification results. In heterotrophic nitrification system, the ammonia nitrogen and total nitrogen removal rate of the bacterial strain TN-14 could reach 97.13% and 93.53% within 24 h. In nitrates denitrification system, the nitrate concentration could decline from 94.24 mg · L(-1) to 39.32 mg · L(-1) within 24 h, where the removal rate was 58.28% and the denitrification rate was 2.28 mg · (L · h)(-1); In nitrite denitrification systems, the initial concentration of nitrite could be declined from 97.78 mg · L(-1) to 21.30 mg x L(-1), with a nitrite nitrogen removal rate of 78.22%, and a denitrification rate of 2.55 mg · (L· h)(-1). Meanwhile, strain TN-14 had the capability of flocculant production, and the flocculating rate could reach 94.74% when its fermentation liquid was used to treat 0.4% kaolin suspension. Strain TN-14 could grow at an ammonia nitrogen concentration as high as 1200 mg · L(-1). In the aspect of actual piggery wastewater treatment by strain TN-14, the removal rate of COD, ammonia nitrogen, TN and TP cloud reached 85.30%, 65.72%, 64.86% and 79.41%, respectively. Strain TN-14 has a good application prospect in biological treatment of real high- ammonia wastewater. PMID:25693403

  4. Ammonium nitrogen removal from slurry-type swine wastewater by pretreatment using struvite crystallization for nitrogen control of anaerobic digestion.

    Science.gov (United States)

    Kim, B U; Lee, W H; Lee, H J; Rim, J M

    2004-01-01

    Precipitation of ammonium together with phosphate and magnesium is a possible alternative for lowering the nitrogen content of wastewater. In this study we examine the removal of ammonium nitrogen and phosphorus from slurry-type swine wastewater containing high concentrations of nutrients by the addition of phosphoric acid along with either calcium oxide or magnesium oxide, which leads to the crystallization of insoluble salts such as hydroxyapatite and struvite. The struvite crystallization method showed a high capacity for the removal of nitrogen when magnesium oxide and phosphoric acid were used as the magnesium and phosphate sources, respectively. When it was applied to swine wastewater containing a high concentration of nitrogen, the injection molar ratio of Mg2+:NH4+:PO4(3-) that gave maximum ammonium nitrogen removal was 3.0:1.0:1.5. PMID:15137426

  5. Towards a plant-wide Benchmark Simulation Model with simultaneous nitrogen and phosphorus removal wastewater treatment processes

    DEFF Research Database (Denmark)

    Flores-Alsina, Xavier; Ikumi, David; Batstone, Damien;

    . This extension aims at facilitating simultaneous carbon, nitrogen and phosphorus (P) removal process development and performance evaluation at a plant-wide level. The main motivation of the work is that numerous wastewater treatment plants (WWTPs) pursue biological phosphorus removal as an alternative......It is more than 10 years since the publication of the Benchmark Simulation Model No 1 (BSM1) manual (Copp, 2002). The main objective of BSM1 was creating a platform for benchmarking carbon and nitrogen removal strategies in activated sludge systems. The initial platform evolved into BSM1_LT and BSM...... to chemical P removal based on precipitation using metal salts, such as Fe or Al. This paper identifies and discusses important issues that need to be addressed to upgrade the BSM2 to BSM2-P, for example: 1) new influent wastewater characteristics; 2) new (bio) chemical processes to account for; 3...

  6. Biological effect of nitrogen ion implantation on stevia

    International Nuclear Information System (INIS)

    Dry seed of stevia were implanted by 35∼150 keV nitrogen ions with various doses. The biological effect in M1 was studied. The results showed that nitrogen ion beam was able to induce variation on chromosome structure in root tip cells. The rate of cells with chromosome aberration was increased with ion beam energy and dose added, but there was on significant linear regression relationship between ion dose and aberration rate. The results indicated the seedling height reduced with the increasing of dose for ion beam. The biological effect of nitrogen ion beam on M1 stevia was lower than that of γ-rays. (6 refs., 1 fig., 4 tabs.)

  7. Study on one-stage Partial Nitritation-Anammox process in Moving Bed Biofilm Reactors: a sustainable nitrogen removal.

    OpenAIRE

    Bertino, Andrea

    2011-01-01

    In the last decade, several novel and cost-effective biological nitrogen removal technologies have been developed. The discovery of anaerobic ammonium oxidation (Anammox), about 15 years ago, has resulted in new opportunities for research and development of sustainable nitrogen removal systems. Compared to conventional nitrification/denitrification, Anammox eliminates necessity of external organic carbon source, has a smaller production of excess sludge, reduces energy demand for aeration (up...

  8. BIOLOGICAL DEGRADATION OF CYANIDE BY NITROGEN-FIXING CYANOBACTERIA

    Science.gov (United States)

    This study examined the ability of nitrogen-fixing Anabaena to biodegrade cyanide in batch reactors. ixed second-order constants were obtained that described the biologically-mediated decrease in cyanide for reactors containing initial cyanide concentrations of 3 ppm. or Anabaena...

  9. An Investigation of the Biochemistry of Biological Phosphorus Removal

    OpenAIRE

    Erdal, Zeynep Kisoglu

    2002-01-01

    Although enhanced biological phosphorus removal (EBPR) and complete biological nutrient removal (BNR) systems can be operated successfully by experienced operators, the accuracy of design and strength of the scientific background need to be reinforced to enable accurate modeling and economically optimal design. One way to accomplish this would be through a better understanding of the biochemical mechanisms and microbial population dynamics that determine the reliability and efficiency of EBPR...

  10. Removal of high concentrated ammonia nitrogen from landfill leachate by landfilled waste layer

    Institute of Scientific and Technical Information of China (English)

    GUO Hui-dong; HE Pin-jing; SHAO Li-ming; LI Guo-jian

    2004-01-01

    The landfill of municipal solid waste(MSW) could be regarded as denitrification reactor and used in ammonia nitrogen biological removal process. In this research, the process was applied to municipal solid waste(MSW) collected in Shanghai, China, which was characterized with high food waste content. The NH4+ removal efficiency in the system of SBR nitrifying reactor followed by fresh and matured landfilled waste layer in series was studied. In the nitrifying reactor, above 90% of NH4+ in leachate was oxidized to NO2- and NO3-. Then high concentrated NO2- and NO3- was removed in the way of denitrification process in fresh landfilled waste layer. At the same time, degradation of fresh landfilled waste was accelerated. Up to the day 120, 136.5 gC/(kg dry waste) and 17.9 gN/(kg dry waste) were produced from waste layer. It accounted for 50.15% and 86.89% of the total carbon and nitrogen content of preliminary fresh waste, which was 4.42 times and 5.17 times higher than that of reference column respectively. After filtering through matured landfilled waste, BOD5 concentration in leachate dropped to below 100 mg/L, which would not affect following nitrification adversely. Because the matured landfilled waste acted as a well methanogenic reactor, 23% of carbon produced accumulatively from fresh landfilled waste degradation was converted into CH4.

  11. Management of microbial community composition, architecture and performance in autotrophic nitrogen removing bioreactors through aeration regimes

    DEFF Research Database (Denmark)

    Mutlu, A. Gizem

    Completely autotrophic nitrogen removal from nitrogen-rich wastewaters through the nitritation -plus- anaerobic ammonium oxidation processes can greatly reduce operational energy costs compared to traditional nitrogen removal processes. The footprint can be further reduced by process intensificat......Completely autotrophic nitrogen removal from nitrogen-rich wastewaters through the nitritation -plus- anaerobic ammonium oxidation processes can greatly reduce operational energy costs compared to traditional nitrogen removal processes. The footprint can be further reduced by process...... some of the collateral impacts could be isolated, increasing process understanding. It was demonstrated that aeration strategy can be used as a powerful tool to manipulate the microbial community composition, its architecture and reactor performance. We suggest operation via intermittent aeration with...

  12. Modeling, Experimentation, and Control of Autotrophic Nitrogen Removal in Granular Sludge Systems

    DEFF Research Database (Denmark)

    Vangsgaard, Anna Katrine

    is convenient for treating anaerobic digester liquor, landfill leachate, or special industrial wastewaters, because costs related to the need for aeration and carbon addition are lowered by 60% and 100%, respectively, compared to conventional nitrification denitrification treatment. Energy and......Complete autotrophic nitrogen removal (CANR) is a novel process that can increase the treatment capacity for wastewaters containing high concentrations of nitrogen and low organic carbon to nitrogen ratios, through an increase of the volumetric removal rate by approximately five times. This process...

  13. Effect of solids retention time and wastewater characteristics on biological phosphorus removal

    DEFF Research Database (Denmark)

    Henze, Mogens; Aspegren, H.; Jansen, J.l.C.;

    2002-01-01

    The paper deals with the effect of wastewater, plant design and operation in relation to biological nitrogen and phosphorus removal and the possibilities to model the processes. Two Bio-P pilot plants were operated for 2.5 years in parallel receiving identical wastewater. The plants had SRT of 4...... in the wastewater, and less by the plant lay-out. The phosphorus removal is mainly dependent on availability in the wastewater of fatty acids but also by the suspended solids in the effluent, which is higher in the plant with nitrificationdenitrification, probably due to a higher SVI or denitrification...... with time which has importance in relation to modelling. The overall conclusion of the comparison between the two plants is that the biological phosphorus removal efficiency under practical operating conditions is affected by the SRT in the plant and the wastewater composition. Thus great care should...

  14. Optimization of biological phosphorus and ammonia removal in a combined fixed and suspended growth wastewater treatment system: Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    This project was conducted to optimize design and operational criteria for enhanced biological phosphorus removal and nitrification of ammonia in the fixed growth reactor-suspended growth reactor (FGR-SGR) process. The research completed the investigation of optimum hydraulic retention times for biological phosphorus removal in both the unaerated and aerated phases of the suspended growth components of the FGR-SGR system, including an assessment of the possibility of reducing suspended growth aeration requirements by using oxidized forms of nitrogen rather than dissolved oxygen for biological phosphorus uptake; investigated the effects on biological phosphorus removal and nitrification of varying the internal recycle flow rates; and investigated the optimum solids retention time, or the optimum operating mixed liquor suspended solids concentration, in the suspended growth component of the system for biological phosphorus removal and nitrification-denitrification.

  15. Effect of ammonia load on efficiency of nitrogen removal in an SBBR with liquid-phase circulation

    OpenAIRE

    C. S. A. Canto; S. M. Ratusznei; J.A.D. RODRIGUES; M. Zaiat; E. Foresti

    2008-01-01

    The removal of biological nitrogen from a synthetic wastewater with different ammonium nitrogen concentrations (50 and 100 mgN-NH4+/L) by a nitrification and denitrification process using a sequencing batch biofilm reactor (SBBR) with liquid-phase circulation was studied. The system with a total working volume of 4.6 L (3.7 L in the reactor and 0.9 L in the reservoir) treated 2.1 L of synthetic wastewater in 12-h cycles. As inoculum two types of biomass were used: an anaerobic/anoxic one from...

  16. CARBONACEOUS, NITROGENOUS AND PHOSPHORUS MATTERS REMOVAL FROM DOMESTIC WASTEWATER BY AN ACTIVATED SLUDGE REACTOR OF NITRIFICATION-DENITRIFICATION TYPE

    OpenAIRE

    MOHAMAD ALI FULAZZAKY

    2009-01-01

    This paper proposes an environmental engineering method based on biotechnology approach as one of the expected solutions that should be considered to implementing the activated sludge for improving the quality of water and living environment, especially to remove the major pollutant elements of domestic wastewater. Elimination of 3 major pollutant elements, i.e., carbon, nitrogen and phosphor containing the domestic wastewater is proposed to carry out biological method of an anoxic-aerobic re...

  17. Removal of arsenic and iron removal from drinking water using coagulation and biological treatment.

    Science.gov (United States)

    Pramanik, Biplob Kumar; Pramanik, Sagor Kumar; Suja, Fatihah

    2016-02-01

    Effects of biological activated carbon (BAC), biological aerated filter (BAF), alum coagulation and Moringa oleifera coagulation were investigated to remove iron and arsenic contaminants from drinking water. At an initial dose of 5 mg/L, the removal efficiency for arsenic and iron was 63% and 58% respectively using alum, and 47% and 41% respectively using Moringa oleifera. The removal of both contaminants increased with the increase in coagulant dose and decrease in pH. Biological processes were more effective in removing these contaminants than coagulation. Compared to BAF, BAC gave greater removal of both arsenic and iron, removing 85% and 74%, respectively. Longer contact time for both processes could reduce the greater concentration of arsenic and iron contaminants. The addition of coagulation (at 5 mg/L dosage) and a biological process (with 15 or 60 min contact time) could significantly increase removal efficiency, and the maximum removal was observed for the combination of alum and BAC treatment (60 min contact time), with 100% and 98.56% for arsenic and iron respectively. The reduction efficiency of arsenic and iron reduced with the increase in the concentration of dissolved organics in the feedwater due to the adsorption competition between organic molecules and heavy metals. PMID:26837833

  18. New insights into the evolutionary history of biological nitrogen fixation

    Directory of Open Access Journals (Sweden)

    Eric eBoyd

    2013-08-01

    Full Text Available Nitrogenase, which catalyzes the ATP-dependent reduction of dinitrogen (N2 to ammonia (NH3, accounts for roughly half of the bioavailable nitrogen supporting extant life. The fundamental requirement for fixed forms of nitrogen for life on Earth, both at present and in the past, has led to broad and significant interest in the origin and evolution of this fundamental biological process. One key question is whether the limited availability of fixed nitrogen was a factor in life’s origin or whether there were ample sources of fixed nitrogen produced by abiotic processes or delivered through the weathering of bolide impact materials to support this early life. If the latter, the key questions become what were the characteristics of the environment that precipitated the evolution of this oxygen sensitive process, when did this occur, and how was its subsequent evolutionary history impacted by the advent of oxygenic photosynthesis and the rise of oxygen in the Earth’s biosphere. Since the availability of fixed sources of nitrogen capable of supporting early life is difficult to glean from the geologic record, there are limited means to get direct insights into these questions. Indirect insights, however, can be gained by deep phylogenetic studies of nitrogenase structural gene products and additional gene products involved in the biosynthesis of the complex metal-containing prosthetic groups associated with this enzyme complex. Insights gained from such studies, as reviewed herein, challenge traditional models for the evolution of biological nitrogen fixation and provide the basis for the development of new conceptual models that explain the stepwise evolution of this highly complex and life sustaining process.

  19. Nitrogen Removal in a Full-Scale Domestic Wastewater Treatment Plant with Activated Sludge and Trickling Filter

    Directory of Open Access Journals (Sweden)

    Davood Nourmohammadi

    2013-01-01

    Full Text Available During the last decade, more stringent effluent requirements concerning the nutrients effluent values have been imposed by legislation and social concern. In this study, efficiency of total nitrogen removal in activated sludge and trickling filter processes (AS/TF was investigated in Tehran North wastewater treatment plant. Biological system in this site was included, anoxic selector tank, aeration tank, final sedimentation, and trickling filter. A part of treated wastewater before chlorination was mixed with supernatant of dewatered sludge and fed to the trickling filter. Supernatant of dewatered sludge with high concentration of NH4-N was diluted by treated wastewater to provide complete nitrification in trickling filter Produced nitrate in trickling filter was arrived to the anoxic tank and converted to nitrogen gas by denitrification. According to the study result, low concentration of organic carbone and high concentration of NH4-N led to nitrification in TF, then nitrate denitrification to nitrogen gas occurred in selector area. NH4-N concentration decreased from 26.8 mg/L to 0.29 mg/L in TF, and NO3-N concentration increased from 8.8 mg/L to 27 mg/L in TF. Consequently, the total nitrogen decreased approximately to 50% in biological process. This efficiency has been observed in returned flow around 24% from final sedimentation into TF. It was concluded that, in comparison with biological nutrient removal processes, this process is very efficient and simple.

  20. Nitrogen transformation and removal in low-order restored urban streams

    Science.gov (United States)

    Tuttle, A. K.; McMillan, S. K.; Clinton, S.

    2010-12-01

    Rapid urbanization of watersheds in the Southeast United States has placed many stressors on low-order streams, including but not limited to high peak flows, reduced biodiversity of plant and animal species, water quality impairments and eutrophication. Urban stream restoration projects seek to mitigate these effects as well as minimize property damage from flooding. Engineered structures such as riffles and steps operate in multiple capacities to enhance ecological function by providing grade control, habitat, and reaeration. These structures may enhance the capacity for low-order urban streams to act as nitrogen sinks by encouraging hyporheic flow, providing substrate for biofilm colonization and trapping carbon. It has been shown that low-order streams with low specific discharge (Q/w) are uniquely positioned to transform and remove nitrogen where a greater proportion of water is exposed to biologically active sediment. This study is currently investigating the seasonal importance and spatial variation of nitrogen transformations in restored and unrestored reaches of low-order streams in Charlotte, NC, USA. Carbon quality and quantity, hydrologic conductivity, transient storage, denitrification and uptake rates were measured at several intervals in the summer and fall of 2010. High flows from storm events appear to significantly affect benthic denitrification rates; a three-fold increase was observed both immediately following and four days after a peak flow event. A greater understanding of denitrifying communities' recovery from flood disturbance is needed to fully restore ecological function to urban streams.

  1. [Advanced nitrogen removal using innovative denitrification biofilter with sustained-release carbon source material].

    Science.gov (United States)

    Tang, Lei; Li, Peng; Zuo, Jian-e; Yuan, Lin; Li, Zai-xing

    2013-09-01

    An innovative denitrification biofilter was developed with polycaprolactone (PCL) as the carbon source and biofilm carrier. The performance of nitrogen removal was investigated with biologically treated effluent from secondary clarifier, and the results indicated that a maximum TN removal efficiency of 98.9% was achieved under the following conditions: influent total nitrogen (TN) concentration 30.0 mg x L(-1), denitrification load 54.0 mg (L x h)(-1), operating temperature 20. 1-22.0 degrees C, hydraulic retention time 0. 5 h; the total organic carbon (TOC) in effluent was 6.5-8.4 mg x L(-1), which was increased by 2.0-3.0 mg x L(-1) compared with that in the influent; the suspended solids (SS) concentration was less than 4.0 mg x L(-1) during operation; nearly 84.2% of the total released organic carbon which was used as electron donor in the denitrification process, was derived in the presence of microbes. The surface of the PCL pellets was observed by scanning electron microscope (SEM), it was shown that thick biofilm was formed on the surface of pellets, and the main microbial species were Bacillus and Trichobacteria. PMID:24289000

  2. [Analysis of Precipitation Formation in Biofilm CANUN Reactor and its effect on Nitrogen Removal].

    Science.gov (United States)

    Fu, Kun-ming; Wang, Hui-fang; Zuo, Zao-rong; Qiu, Fu-guo

    2015-08-01

    A CANON reactor with polymeric sponge as carrier was started by incubating sludge from another CANON reactor using synthetic inorganic ammonia-rich wastewater as raw water, and was operated at 30 degrees C +/- 1 degree C, pH 6.92-8.52. The precipitation on the surface of carriers was studied in this paper, including influence on nitrogen removal efficiency, causes for formation and composition. The results showed that: (1) the precipitation could influence the distribution of substrate to undermine the performance of CANON reactors; (2) the precipitation was calcium carbohydrate; (3) the production of precipitation may be a common result of four effects that were the regulatory effect of microorganisms on pH value, stripping effect, the role of extracellular polymers, adsorption of sponge and simultaneous chemical, biological reactions; (4) once the precipitation formed, it was difficult to recover to normal. Therefore, some measures are necessary to avoid precipitation, including: (1) raw water pretreatment to reduce the concentrations of Ca2 and Mg2. (2) ensuring short-cut nitrification stable, which could avoid increase of pH because of reduction of DO; (3) we can choose other carriers to reduce precipitation, which must ensure the optimal total nitrogen removal performance and stable short-cut nitrification. PMID:26592023

  3. Effect of dissolved oxygen on nitrogen removal and process control in aerobic granular sludge reactor

    International Nuclear Information System (INIS)

    A sequencing batch reactor (SBR) with aerobic granular sludge was operated to determine the effect of different DO concentrations on biological nitrogen removal process and to investigate the spatial profiles of DO, ORP and pH as online control parameters in such systems. The results showed that DO concentration had a significant effect on nitrification efficiencies and the profiles of DO, ORP and pH. The specific nitrification rate was decreased from 0.0595 mgNH4+-N/(gMLSS min) to 0.0251 mgNH4+-N/(gMLSS min) after DO concentration was dropped off from 4.5 mg/L to 1.0 mg/L. High DO concentration improved the nitrification and increased the volumetric NH4+-N removal. Low DO concentration enhanced TIN removal, while prolonged the nitrification duration. Also there existed a good correlation between online control parameters (ORP, pH) and nutrient (COD, NH4+-N, NO2--N, NO3--N) variations in aerobic granular sludge reactor when DO was 2.5 mg/L, 3.5 mg/L and 4.5 mg/L. However it was difficult to identify the end of nitrification and denitrification when DO was 1.0 mg/L, due to no apparent bending points on ORP and pH curves. In conclusion, the optimal DO concentration was suggested at 2.5 mg/L as it not only achieved high nitrogen removal efficiency and decreased the reaction duration, but also saved operation cost by aeration and mixing.

  4. Identification of microorganisms involved in nitrogen removal from wastewater treatment systems by means of molecular biology techniques; Identificacion de microorganismos implicados en la eliminacion de nitrogeno en sistemas de tratamiento de aguas residuales mediante tecnicas de biologia molecular

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, M.; Alonso-Gutierrez, J.; Campos, J. L.; Mendez, R.; Mosquera-Corral, A.

    2010-07-01

    The identification of the main bacteria populations present in the granular biomass from a biological reactor treating wastewater has been performed by applying two different molecular biology techniques. By means of the DGGE technique five different genera of heterotrophic bacteria (Thiothrix, Thauera, Cloroflexi, Comamanas y Zoogloea) and one of ammonia oxidizing bacteria (Nitrosomanas) were identified. The FISH technique, based on microscopy, allowed the in situ visualization and quantification of those microorganisms. Special attention was paid to filamentous bacteria distribution (Thiothrix and Cloroflexi) which could exert a structural function in aerobic granular sludge. (Author) 26 refs.

  5. Advanced low carbon-to-nitrogen ratio wastewater treatment by electrochemical and biological coupling process.

    Science.gov (United States)

    Deng, Shihai; Li, Desheng; Yang, Xue; Zhu, Shanbin; Xing, Wei

    2016-03-01

    Nitrogen pollution in ground and surface water significantly affects the environment and its organisms, thereby leading to an increasingly serious environmental problem. Such pollution is difficult to degrade because of the lack of carbon sources. Therefore, an electrochemical and biological coupling process (EBCP) was developed with a composite catalytic biological carrier (CCBC) and applied in a pilot-scale cylindrical reactor to treat wastewater with a carbon-to-nitrogen (C/N) ratio of 2. The startup process, coupling principle, and dynamic feature of the EBCP were examined along with the effects of hydraulic retention time (HRT), dissolved oxygen (DO), and initial pH on nitrogen removal. A stable coupling system was obtained after 51 days when plenty of biofilms were cultivated on the CCBC without inoculation sludge. Autotrophic denitrification, with [Fe(2+)] and [H] produced by iron-carbon galvanic cells in CCBC as electron donors, was confirmed by equity calculation of CODCr and nitrogen removal. Nitrogen removal efficiency was significantly influenced by HRT, DO, and initial pH with optimal values of 3.5 h, 3.5 ± 0.1 mg L(-1), and 7.5 ± 0.1, respectively. The ammonia, nitrate, and total nitrogen (TN) removal efficiencies of 90.1 to 95.3 %, 90.5 to 99.0 %, and 90.3 to 96.5 % were maintained with corresponding initial concentrations of 40 ± 2 mg L(-1) (NH3-N load of 0.27 ± 0.01 kg NH3-N m(-3) d(-1)), 20 ± 1 mg L(-1), and 60 ± 2 mg L(-1) (TN load of 0.41 ± 0.02 kg TN m(-3) d(-1)). Based on the Eckenfelder model, the kinetics equation of the nitrogen transformation along the reactor was N e  = N 0 exp (-0.04368 h/L(1.8438)). Hence, EBCP is a viable method for advanced low C/N ratio wastewater treatment. PMID:26564190

  6. CARBONACEOUS, NITROGENOUS AND PHOSPHORUS MATTERS REMOVAL FROM DOMESTIC WASTEWATER BY AN ACTIVATED SLUDGE REACTOR OF NITRIFICATION-DENITRIFICATION TYPE

    Directory of Open Access Journals (Sweden)

    MOHAMAD ALI FULAZZAKY

    2009-03-01

    Full Text Available This paper proposes an environmental engineering method based on biotechnology approach as one of the expected solutions that should be considered to implementing the activated sludge for improving the quality of water and living environment, especially to remove the major pollutant elements of domestic wastewater. Elimination of 3 major pollutant elements, i.e., carbon, nitrogen and phosphor containing the domestic wastewater is proposed to carry out biological method of an anoxic-aerobic reactor therein these types of pollutants should be consecutively processed in three steps. Firstly, eliminate the carbonaceous matter in the aerobic reactor. Secondly, to remove the carbonaceous and nitrogenous matters, it is necessary to modify the reactor’s nature from the aerobic condition to an anoxic-aerobic reactor. And finally, when the cycle of nitrification-denitrification is stable to achieve the target’s efficiency of reactor by adding the ferric iron into the activated sludge, it can be continued to remove the carbonaceous, nitrogenous and phosphorous matters simultaneously. The efficiency of carbonaceous and nitrogenous matters removal was confirmed with the effluent standard, COD is less than 100 mgO2/L and the value of global nitrogen is less than 10 mgN/L. The effectiveness of suspended matter removal is higher than 90% and the decantation of activated sludge is very good as identifying the Molhman’s index is below of 120 mL/L. The total phosphorus matter removal is more effective than the soluble phosphorus matter. By maintaining the reactor’s nature at the suitable condition, identifying the range of pH between 6.92 and 7.16 therefore the excellent abatement of phosphor of about 80% is achieving with the molar Fe/P ratio of 1.4.

  7. Nitrogen removal from raw landfill leachate by an algae-bacteria consortium.

    Science.gov (United States)

    Sniffen, Kaitlyn D; Sales, Christopher M; Olson, Mira S

    2016-01-01

    A remediation system for the removal of nitrogen from landfill leachate by a mixed algae-bacteria culture was investigated. This system was designed to treat leachate with minimal inputs and maintenance requirements, and was operated as an open semi-batch reactor in an urban greenhouse. The results of this study showed a maximum nitrogen removal rate of 9.18 mg N/(L·day) and maximum biomass density of 480 mg biomass/L. The ammonia removal rates of this culture increased with increasing initial ammonia concentration; maximum nitrogen removal occurred at an ammonia concentration of 80 mg N-NH3/L. At starting ammonia concentrations above 80 mg N-NH3/L a reduction in nitrogen removal was seen; this inhibition is hypothesized to be caused by ammonia toxicity. This inhibiting concentration is considerably higher than that of many other published studies. PMID:26877028

  8. Biological methods of dye removal from textile effluents - A review

    OpenAIRE

    Archna; Lokesh KN; RR Sivakiran

    2012-01-01

    Textile dyes are molecules designed to impart permanent colours to textile fabrics. They pose an environmental problem due to their toxicity and decrease the aesthetic value of water bodies into which they are discharged. Current physico-chemical technologies for dye removal cannot remove all classes of dyes, and two or more technologies are usually combined to achieve satisfactory decolourisation efficiencies. Direct biological treatment using fungi or bacteria can also be employed, but nutr...

  9. Organic and nitrogen removal from landfill leachate in aerobic granular sludge sequencing batch reactors

    International Nuclear Information System (INIS)

    Highlights: ► Aerobic granular sludge SBR was used to treat real landfill leachate. ► COD removal was analyzed kinetically using a modified model. ► Characteristics of nitrogen removal at different ammonium inputs were explored. ► DO variations were consistent with the GSBR performances at low ammonium inputs. - Abstract: Granule sequencing batch reactors (GSBR) were established for landfill leachate treatment, and the COD removal was analyzed kinetically using a modified model. Results showed that COD removal rate decreased as influent ammonium concentration increasing. Characteristics of nitrogen removal at different influent ammonium levels were also studied. When the ammonium concentration in the landfill leachate was 366 mg L−1, the dominant nitrogen removal process in the GSBR was simultaneous nitrification and denitrification (SND). Under the ammonium concentration of 788 mg L−1, nitrite accumulation occurred and the accumulated nitrite was reduced to nitrogen gas by the shortcut denitrification process. When the influent ammonium increased to a higher level of 1105 mg L−1, accumulation of nitrite and nitrate lasted in the whole cycle, and the removal efficiencies of total nitrogen and ammonium decreased to only 35.0% and 39.3%, respectively. Results also showed that DO was a useful process controlling parameter for the organics and nitrogen removal at low ammonium input.

  10. Development of a method for direct biological removal of ammonium to nitrogen in treatment of waste waters of the anaerobic sludge digestion - deammonification. Final report; Entwicklung eines Verfahrens zur direkten biologischen Umsetzung von Ammonium zu Stickstoff bei der Behandlung von Abwaessern der Anaerob-Klaerschlammfaulung - Deammonifikation. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Rosenwinkel, K.H.; Seyfried, C.F.; Kunst, S.; Diekmann, H.; Hippen, A.; Helmer, C.; Scholten, E.

    2001-07-01

    The nitrogen elimination in municipal and industrial wastewater continues to play a major role in wastewater treatment, especially since the Wastewater Directive (AbwV) from 1997 introduced several changes in the requirements and regulations in regard to the pollutant and nutrient removal. As particularly the nitrogen elimination often makes for a considerable cost factor in wastewater treatment, especially when part-streams with high nitrogen loads must be (co-)treated, there is a constant search for economically viable treatment concepts. In this research project, the method of deammonification was developed, that is the process sequence of aerobic nitritation and anoxic ammonium oxidation ('biological comproportioning' of ammonium and nitrite into molecular nitrogen), which is based completely on the metabolism processes of autotrophic micro-organisms, which leads to saving potentials, especially of the carbon demand. Because of the shortened aerobic oxidation steps and the application of biofilm technology, it is also possible to reduce the oxygen demand and the reaction volume. In regard to the purposeful application of deammonification in operation technology, the project steps were targeted to determine the process-defining parameters and to check suitable method technologies and operation control systems in greater detail. To achieve this, the crucial frame conditions for the realisation and the operation performance of the autotrophic nitrogen elimination were defined on the basis of industrial and pilot-technical examinations under consideration of the (micro-)biological connections. Eventually, directives on the establishment of a stable deammonification operation could be derived. On the one hand, we ran a stock-taking of the operation of three industrial leachate treatment plants, on the other hand we operated test-plants on sludge-water treatment. Furthermore, various examinations with different reactor configurations and purposeful

  11. Evaluation of ammonia-nitrogen removal efficiency from aqueous solutions by ultrasonic irradiation in short sonication periods.

    Science.gov (United States)

    Ozturk, Emrah; Bal, Nazire

    2015-09-01

    In this study, mechanisms and efficiency of ammonia-nitrogen removal from aqueous solutions by ultrasonic irradiation were investigated. Depending on the factors affecting the sonication (initial concentration, initial pH, ultrasonic power density and sonication period), sonication tests were carried out and ammonium-nitrogen removal efficiency by ultrasonic irradiation was determined. In these experiments, ammonia-nitrogen removal efficiency was achieved in the range of 8-64%. In short sonication periods, the best ammonia-nitrogen removal efficiency was achieved at pH 8.2-11. Lower ammonia-nitrogen removal efficiency was observed in high initial ammonia-nitrogen concentration of solutions. It was observed that high initial ammonia-nitrogen concentrations may led to decreased ammonia-nitrogen removal efficiency however quantity of ammonia-nitrogen removal was higher. Because high initial concentration had a negative impact on the sonochemical reactions the heat of cavitation bubbles was reduced. Ammonia-nitrogen removal efficiency was increased with ultrasonic density and sonication period. This study showed that effective ammonia-nitrogen removal could be achieved by the ultrasonic irradiation in short sonication periods (as 60-600 s). Specific cost of ammonia-nitrogen removal by the ultrasonic irradiation from simulated ground water, surface water, wastewater and landfill leachate was also calculated. The specific removal cost was varied between 0.01 and 0.25$/g ammonia-nitrogen. PMID:25753490

  12. Role of extracellular exopolymers on biological phosphorus removal

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-nan; XUE Gang; YU Shui-li; ZHAO Fang-bo

    2006-01-01

    Three sequencing batch reactors supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal although all of the three reactors were seeded from the same sludge. With the measurement of poly-β-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPS) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPS played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency.

  13. Nitrogen removal from old landfill leachate with SNAP technology using biofix as a biomass carrier.

    Science.gov (United States)

    Vo, Thanh Tung; Nguyen, Tan Phong

    2016-08-01

    Single-stage nitrogen removal using Anammox and partial nitritation (SNAP) is a novel technology developed in recent years for removing nitrogen. To evaluate the ability of SNAP technology to remove nitrogen in old landfill leachate under the conditions in Vietnam, we conducted a survey with 7 different nitrogen loading rates of 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4 kg-N/m(3) day and a concentration from 100 to 700 mg-N/L. The operating conditions were as follows: DO at 1.0-5.3 mg/L, HRT at 12 h, and pH at 7.5-7.8. The biomass carrier was a biofix made from acrylic fiber. The maximum ammonium conversion and nitrogen removal efficiency were approximately 98% and 85%, respectively, at 1.2 kg-N/m(3) day. In general, the nitrogen removal efficiency increased and stabilized at the end of each loading rate. The first step showed that SNAP could potentially be applied in real life for removing nitrogen from old landfill leachate. PMID:27005592

  14. Nitrogen removal by Providencia rettgeri strain YL with heterotrophic nitrification and aerobic denitrification.

    Science.gov (United States)

    Ye, Jun; Zhao, Bin; An, Qiang; Huang, Yuan-Sheng

    2016-09-01

    Providencia rettgeri strain YL shows the capability of nitrogen removal under sole aerobic conditions. By using isotope ratio mass spectrometry, (15)N-labelled N2O and N2 were detected in aerobic batch cultures containing [Formula: see text], [Formula: see text] or [Formula: see text]. Strain YL converted [Formula: see text], [Formula: see text] and [Formula: see text] to produce more N2O than N2 in the presence of [Formula: see text]. An (15)N isotope tracing experiment confirmed that the nitrogen removal pathway of strain YL was heterotrophic nitrification-aerobic denitrification. The optimal treatment conditions for nitrogen removal were pH of 8, C/N ratio of 12, temperature of 25°C and shaking speed of 105 rpm. A continuous aerobic bioreactor inoculated with strain YL was developed. With an influent [Formula: see text] concentration of 90-200 mg/L, the [Formula: see text] removal efficiency ranged from 80% to 97% and the total nitrogen removal efficiency ranged from 72% to 95%. The nitrogen balance in the continuous bioreactor revealed that approximately 35-52% of influent [Formula: see text] was denitrified aerobically to form gaseous nitrogen. These findings show that the P. rettgeri strain YL has potential application in wastewater treatment for nitrogen removal under sole aerobic conditions. PMID:26824874

  15. Biological Nitrogen Fixation in Two Tropical Forests: Ecosystem-Level Patterns and Effects of Nitrogen Fertilization

    OpenAIRE

    Cusack, Daniela F.; Silver, Whendee; McDowell, William H.

    2009-01-01

    Humid tropical forests are often characterized by large nitrogen (N) pools, and are known to have large potential N losses. Although rarely measured, tropical forests likely maintain considerable biological N fixation (BNF) to balance N losses. We estimated inputs of N via BNF by free-living microbes for two tropical forests in Puerto Rico, and assessed the response to increased N availability using an on-going N fertilization experiment. Nitrogenase activity was measured across forest strata...

  16. Nitrogen and phosphorous removal from municipal wastewater by constructed welt lands

    International Nuclear Information System (INIS)

    Several physical, chemical, biological methods and combination of them are used for domestic wastewater nitrogen and phosphrous removal. In this study, subsurface horizontal constructed wetland with length of 13-6 m, width of 10 m and depth of 0.55 m with Phargmites austral is is used. Soil porosity was 40 percent. The system irrigated with domestic wastewater. The wastewater COD, Tn, TKN and PO4 concentration was 300, 45-57 and 45-92 mg/1 respectively. Hydraulic loading increased from 5 cm/day to 7.2 cm/d while detention time decreased from 4.2 days to 3 days. Removal percent of COD, TN, TKN and PO4=at hydraulic equal to 5 cm/d and detention time of 4.2 days was 90,83,94 and 92 percent respectively. the study also indicates that removal percent of COD/Tn/TKN and PO4=at loading of 7.2 cm/day was 93,8,86 and 73 respectively

  17. Microbial nitrogen removal pathways in integrated vertical-flow constructed wetland systems.

    Science.gov (United States)

    Hu, Yun; He, Feng; Ma, Lin; Zhang, Yi; Wu, Zhenbin

    2016-05-01

    Microbial nitrogen (N) removal pathways in planted (Canna indica L.) and unplanted integrated vertical-flow constructed wetland systems (IVCWs) were investigated. Results of, molecular biological and isotope pairing experiments showed that nitrifying, anammox, and denitrifying bacteria were distributed in both down-flow and up-flow columns of the IVCWs. Further, the N transforming bacteria in the planted IVCWs were significantly higher than that in the unplanted ones (p<0.05). Moreover, the potential nitrification, anammox, and denitrification rates were highest (18.90, 11.75, and 7.84nmolNg(-1)h(-1), respectively) in the down-flow column of the planted IVCWs. Significant correlations between these potential rates and the absolute abundance of N transformation genes further confirmed the existence of simultaneous nitrification, anammox, and denitrification (SNAD) processes in the IVCWs. The anammox process was the major N removal pathway (55.6-60.0%) in the IVCWs. The results will further our understanding of the microbial N removal mechanisms in IVCWs. PMID:26897412

  18. Controlled biomass removal - the key parameter to achieve enhanced biological phosphorus removal in biofilm systems

    DEFF Research Database (Denmark)

    Morgenroth, E.

    1999-01-01

    In contrast to enhanced biological phosphorus removal (EBPR) in activated sludge systems mass transfer processes have a major influence on overall phosphorus removal in biofilm reactors. Based on results from a laboratory scale sequencing batch biofilm reactor (SBBR) and from a mathematical model......) had only a minor effect on overall phosphorus removal. Soluble components fully penetrate the biofilm at certain times during the SBBR cycle as a consequence of SBBR operation with large concentration variations over the cycle time. The limiting processes for EBPR is the efficient removal...... of phosphorus rich biomass from the reactor. Biomass at the base of the biofilm that is not removed during backwashing will release accumulated phosphorus due to lysis or endogenous respiration and will not contribute to net phosphorus removal. For efficient operation of EBPR in biofilm systems regular...

  19. Tracing the limits of organic micropollutant removal in biological wastewater treatment.

    Science.gov (United States)

    Falås, Per; Wick, Arne; Castronovo, Sandro; Habermacher, Jonathan; Ternes, Thomas A; Joss, Adriano

    2016-05-15

    Removal of organic micropollutants was investigated in 15 diverse biological reactors through short and long-term experiments. Short-term batch experiments were performed with activated sludge from three parallel sequencing batch reactors (25, 40, and 80 d solid retention time, SRT) fed with synthetic wastewater without micropollutants for one year. Despite the minimal micropollutant exposure, the synthetic wastewater sludges were able to degrade several micropollutants present in municipal wastewater. The degradation occurred immediately after spiking (1-5 μg/L), showed no strong or systematic correlation to the sludge age, and proceeded at rates comparable to those of municipal wastewater sludges. Thus, the results from the batch experiments indicate that degradation of organic micropollutants in biological wastewater treatment is quite insensitive to SRT increases from 25 to 80 days, and not necessarily induced by exposure to micropollutants. Long-term experiments with municipal wastewater were performed to assess the potential for extended biological micropollutant removal under different redox conditions and substrate concentrations (carbon and nitrogen). A total of 31 organic micropollutants were monitored through influent-effluent sampling of twelve municipal wastewater reactors. In accordance with the results from the sludges grown on synthetic wastewater, several compounds such as bezafibrate, atenolol and acyclovir were significantly removed in the activated sludge processes fed with municipal wastewater. Complementary removal of two compounds, diuron and diclofenac, was achieved in an oxic biofilm treatment. A few aerobically persistent micropollutants such as venlafaxine, diatrizoate and tramadol were removed under anaerobic conditions, but a large number of micropollutants persisted in all biological treatments. Collectively, these results indicate that certain improvements in biological micropollutant removal can be achieved by combining different

  20. Nitrogen removal from plasma-facing components by ion cyclotron wall conditioning in TEXTOR

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco, A.G., E-mail: alvarogc@kth.se [Department of Fusion Plasma Physics, Royal Institute of Technology (KTH), Association VR, 100 44 Stockholm (Sweden); Wauters, T. [Laboratory of Plasma Physics, ERM/KMS, Association Belgian State, Brussels (Belgium); Petersson, P. [Department of Fusion Plasma Physics, Royal Institute of Technology (KTH), Association VR, 100 44 Stockholm (Sweden); Drenik, A. [Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Rubel, M. [Department of Fusion Plasma Physics, Royal Institute of Technology (KTH), Association VR, 100 44 Stockholm (Sweden); Crombé, K. [Laboratory of Plasma Physics, ERM/KMS, Association Belgian State, Brussels (Belgium); Douai, D. [CEA, IRFM, Association Euratom-CEA, 13108 St Paul lez Durance (France); Fortuna, E. [Faculty of Materials Science, Warsaw University of Technology, Association IPPLM, 02-507 Warsaw (Poland); Kogut, D. [CEA, IRFM, Association Euratom-CEA, 13108 St Paul lez Durance (France); Kreter, A. [IEK-4, Forschungszentrum Jülich, Association EURATOM–FZJ (Germany); Lyssoivan, A. [Laboratory of Plasma Physics, ERM/KMS, Association Belgian State, Brussels (Belgium); Möller, S. [IEK-4, Forschungszentrum Jülich, Association EURATOM–FZJ (Germany); Pisarek, M. [Institute of Physical Chemistry PAS, Kasprzaka 44/52, 01-224 Warsaw (Poland); Vervier, M. [Laboratory of Plasma Physics, ERM/KMS, Association Belgian State, Brussels (Belgium)

    2015-08-15

    The efficiency of ion cyclotron wall conditioning (ICWC) in the removal of nitrogen from plasma-facing components in TEXTOR was assessed. In two experiments the wall was loaded with nitrogen and subsequently cleaned by ICWC in deuterium and helium. The retention and removal of nitrogen was studied in-situ by means of mass spectrometry, and ex-situ by surface analysis of a set of graphite, tungsten and TZM plates installed on test limiter systems. {sup 15}N rare isotope was used as a marker. The results from the gas balance showed that about 25% of the retained nitrogen was removed after ICWC cleaning, whereas surface analysis of the plates based on ToF-HIERDA showed an increase of the deposited species after the cleaning. This indicates that during ICWC operation on carbon devices, nitrogen is not only pumped out but also transported to other locations on the wall. Additionally, deuterium surface content was studied before and after ICWC cleaning.

  1. 氧化沟的脱氮除磷%Nitrogen and phosphorus removal of oxidation ditch

    Institute of Scientific and Technical Information of China (English)

    郭继锋; 杨云龙

    2009-01-01

    阐述了氧化沟脱氮除磷的特点、机理、影响氧化沟脱氮除磷的因素及各种形式氧化沟的脱氮除磷,最后提出了氧化沟的未来发展方向,以期既节约能源又实现最佳的除磷脱氮效果.%The characteristics and working mechanism of nitrogen and phosphorus removal of oxidation ditch are elaborated as well as the fac-tors influencing the removal ratio of nitrogen and phosphorus and various nitrogen and phosphorus removal ways of oxidation ditches. In the end the developmental direction of oxidation ditch is pointed out in order to realize optimal removal effect of nitrogen and phosphorus on the prince of saving energy.

  2. Ecological Limits to Terrestrial Biological Carbon Dioxide Removal

    Science.gov (United States)

    Torn, M. S.; Smith, L. J.; Mishra, U.; Sanchez, D.; Williams, J.

    2014-12-01

    Many climate change mitigation scenarios include terrestrial atmospheric carbon dioxide removal (BCDR) or carbon neutral bioenergy production through bioenergy with carbon capture and storage (BECS) or afforestation/reforestation. Very high sequestration potentials for these strategies have been reported, and we evaluate the potential ecological limits (e.g., land and resource requirements) to implementation at the 1 Pg C y-1 scale relevant to climate change mitigation for U.S. and global scenarios. We estimate that removing 1 Pg C y-1 via tropical afforestation would require at least 7×106 ha y-1 of land, 0.09 Tg y-1 of nitrogen, and 0.2 Tg y-1 of phosphorous, and would increase evapotranspiration from those lands by almost 50%. Because of improved carbon capture technologies, we are updating (and reducing) our previous estimates for switchgrass BECS (previous estimate was 2×108 ha land and 20 Tg y-1 of nitrogen (20 % of global fertilizer nitrogen production)). Miscanthus could meet the same biomass production with much lower N demand. Moreover, transitioning the U.S land currently under corn- ethanol production to no-till perennial grasses for bioenergy would meet U.S. needs and have additional environmental benefits (such as improved wildlife habitat and soil restoration). Thus, there are both signficant ecological limits to BCDR as well as potential ecological benefits, depending on implementation.

  3. Removal of carbonaceous and nitrogenous pollutants from a synthetic wastewater using a membrane-coupled bioreactor.

    Science.gov (United States)

    Ghosh, Sudeshna; LaPara, Timothy M

    2004-09-01

    Two modified Ludzack-Ettinger (MLE)-type membrane-coupled bioreactors (MBRs) were investigated in this study for the purpose of removing both nitrogenous and carbonaceous pollutants from a synthetic wastewater. During the first MBR experiment, removal efficiencies were high (>90%) for chemical oxygen demand (COD) and ammonia, but total nitrogenous pollutant removal efficiency was poor (approximately 25%). Bacterial community analysis of ammonia oxidizing bacteria (AOB) by a nested PCR-DGGE approach detected two Nitrosomonas-like populations and one Nitrosospira-like population. During the initial portion of the second MBR experiment, COD and ammonia removal efficiencies were similar to the first MBR experiment until the COD of the influent wastewater was increased to provide additional electron donors to support denitrification. Total nitrogen removal efficiencies eventually exceeded 90%, with a hydraulic residence time (HRT) of 24 h and a recirculation ratio of 8. When the HRT of the MBR experiment was decreased to 12 h, however, ammonia removal efficiency was adversely affected. A subsequent increase in the HRT to 18 h helped improve removal efficiencies for both ammonia (>85%) and total nitrogenous compounds (approximately 70%). Our research demonstrates that MBRs can be effectively designed to remove both carbonaceous and nitrogenous pollutants. The ability of the microbial community to switch between anoxic (denitrifying) and oxic (nitrifying) conditions, however, represents a critical process constraint for the application of MLE-type MBR systems, such that little benefit is gained compared to conventional designs. PMID:15338423

  4. Impact of photosynthesis and transpiration on nitrogen removal in constructed wetlands

    Institute of Scientific and Technical Information of China (English)

    LUO Weiguo; WANG Shihe; HUANG Juan; YAN Lu; HUANG Jun

    2007-01-01

    To determine the impact of photosynthesis and transpiration on nitrogen removal in wetlands,an artificial wetland planted with reeds was constructed to treat highly concentrated domestic wastewater.Under different meteorological and hydraulic conditions,the daily changes of photosynthesis and transpiration of reeds,as well as nitrogen removal efficiency were measured.It was found that net photosynthesis rate per unit leaf area was maintained on a high Photon Flux Density was high during the day.Meanwhile,TN and NH4+-N removal efficiency rose to 79.6% and 89.6%,respectively-the maximum values observed in the test.Correlation coefficient analysis demonstrated a positive correlation among photon flux density,net photosynthetic rate,transpiration rate,and TN and NH4+-N removal efficiency.In contrast,there was a negative correlation between stomatal conductance and TN and NH4+-N removal efficiency.Results suggest that the photosynthesis and transpiration of wetland plants have a great impact on nitrogen removal efficiency of wetlands,which can be enhanced by an increase in the photosynthesis and transpiration rate.In addition,the efficiency of water usage by reeds and nitrogen removal efficiency could be affected by the water level in wetlands;a higher level boosts nitrogen removal efficiency.

  5. Effects of Sludge Retention Times on Nutrient Removal and Nitrous Oxide Emission in Biological Nutrient Removal Processes

    Directory of Open Access Journals (Sweden)

    Bo Li

    2014-03-01

    Full Text Available Sludge retention time (SRT is an important factor affecting not only the performance of the nutrient removal and sludge characteristics, but also the production of secondary pollutants such as nitrous oxide (N2O in biological nutrient removal (BNR processes. Four laboratory-scale sequencing batch reactors (SBRs, namely, SBR5, SBR10, SBR20 and SBR40 with the SRT of 5 d, 10 d, 20 d and 40 d, respectively, were operated to examine effects of SRT on nutrient removal, activated sludge characteristics and N2O emissions. The removal of chemical oxygen demand or total phosphorus was similar under SRTs of 5–40 d, SRT mainly affected the nitrogen removal and the optimal SRT for BNR was 20 d. The molecular weight distribution of the effluent organic matters was in the range of 500–3,000 Da under SRTs of 5–40 d. The lowest concentration of the effluent soluble microbial products concentration was obtained at the SRT of 5 d. Nitrifier growth was limited at a short SRT and nitrite existed in the effluent of SBR5. With increasing SRTs, mixed liquor suspended solids concentration increased while the excess sludge production was reduced due to the high endogenous decay rate at high SRTs. Endogenous decay coefficients were 0.020 d−1, 0.036 d−1, 0.037 d−1 and 0.039 d−1 under SRTs of 5–40 d, respectively. In BNR, the N2O emission occurred mainly during the aerobic phase and its emission ratio decreased with increasing SRTs. The ratio between the N2O-N emission and the removed ammonium nitrogen in the aerobic phase was 5%, 3%, 1.8% and 0.8% at the SRT of 5 d, 10 d, 20 d and 40 d, respectively. With low concentrations of dissolved oxygen and high concentrations of oxidized nitrogen, the N2O emission was significantly accelerated due to heterotrophic denitrification activities.

  6. Nitrogen removal in treatment wetlands : Factors influencing spatial and temporal variations

    OpenAIRE

    Kallner Bastviken, Sofia

    2006-01-01

    Decreasing the nitrogen transport from land to surrounding seas is a major task throughout the world to limit eutrophication of the coastal areas. Several approaches are currently used, including the establishment of wetlands, to decrease the transport of nitrogen. Wetlands represent ecosystems where the nitrogen removal from water can be efficient given that they are appropriately designed. The aim of this thesis was to investigate and quantify the effect of critical factors that regulate th...

  7. The effect of nitrogen on phosphorus and potassium removal by cauliflower

    NARCIS (Netherlands)

    Everaarts, A.P.; Moel, de C.P.

    2009-01-01

    The effect of the amount of nitrogen applied and of the method of application on the amounts of phosphorus and potassium removed from the field with the product in cauliflower cultivation was studied in three field experiments. Band placement or split application of nitrogen did not influence phosph

  8. Biological nutrient removal from leachate using a pilot liquid-solid circulating fluidized bed bioreactor (LSCFB).

    Science.gov (United States)

    Eldyasti, Ahmed; Chowdhury, Nabin; Nakhla, George; Zhu, Jesse

    2010-09-15

    Biological treatment of landfill leachate is a concern due to toxicity, high ammonia, low biodegradable organic matter concentrations, and low carbon-to-nitrogen ratio. To study the reliability and commercial viability of leachate treatment using an integrated liquid-solid circulating fluidized bed bioreactor (LSCFB), a pilot-scale LSCFB was established at the Adelaide Pollution Control Plant, London, Ontario, Canada. Anoxic and aerobic columns were used to optimize carbon and nutrient removal capability from leachate using 600 microm lava rock with a total porosity of 61%, at empty bed contact times (EBCTs) of 0.55, 0.49, and 0.41 d. The LSCFB achieved COD, nitrogen, and phosphorus removal efficiencies of 85%, 80%, and 70%, respectively at a low carbon-to-nitrogen ratio of 3:1 and nutrients loading rates of 2.15 kg COD/(m(3) d), 0.70 kg N/(m(3) d), and 0.014 kg P/(m(3) d), as compared with 60-77% COD and 70-79% nitrogen removal efficiencies achieved by upflow anaerobic sludge blanket (UASB) and moving bed bioreactor (MBBR), respectively. The LSCFB effluent characterized by biological solids retention times (SRTs) of 31, 38 and 44 d. PMID:20510504

  9. Simultaneous nitrogen and phosphorus removal by a novel sequencing batch moving bed membrane bioreactor for wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Yang Shuai [Key Laboratory of Industrial Ecology and Environmental Engineering, MOE, School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Yang Fenglin, E-mail: yangshuai1125@163.com [Key Laboratory of Industrial Ecology and Environmental Engineering, MOE, School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Fu Zhimin; Wang Tao [Key Laboratory of Industrial Ecology and Environmental Engineering, MOE, School of Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Lei Ruibo [State Key Laboratory of Coastal and Offshore Engineering, School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian 116024 (China)

    2010-03-15

    Biological nutrient removal (BNR) was investigated in a sequencing batch membrane bioreactor which used carriers instead of activated sludge named a sequencing batch moving bed membrane bioreactor (SBMBMBR). The SBMBMBR performed well on carbon and nitrogen removal at different COD/TN ratios. COD, TN and ammonium nitrogen removal efficiencies averaged at 93.5%, 82.6% and 95.6%, respectively. The TP removal was closely correlated with the length of anaerobic phase and aerobic phase. When anaerobic time and aerobic time were both 2 h, the average TP removal efficiency reached to 84.1% at influent TP concentration of 12.4 mg/L. DO in aerobic phase was an important factor affecting nutrient removal, and the optimal DO was about 3 mg/L. There was a small amount of denitrifying phosphorus accumulating organisms (DPAOs) in SBMBMBR which resulted from the anoxic microenvironment existed in the inner of the biofilm. Fluorescence in situ hybridization (FISH) results of microbes showed the composition and spatial structure of the microbial community in the reactor. Furthermore, sequencing batch mode operation was propitious to retard membrane fouling.

  10. Simultaneous nitrogen and phosphorus removal by a novel sequencing batch moving bed membrane bioreactor for wastewater treatment

    International Nuclear Information System (INIS)

    Biological nutrient removal (BNR) was investigated in a sequencing batch membrane bioreactor which used carriers instead of activated sludge named a sequencing batch moving bed membrane bioreactor (SBMBMBR). The SBMBMBR performed well on carbon and nitrogen removal at different COD/TN ratios. COD, TN and ammonium nitrogen removal efficiencies averaged at 93.5%, 82.6% and 95.6%, respectively. The TP removal was closely correlated with the length of anaerobic phase and aerobic phase. When anaerobic time and aerobic time were both 2 h, the average TP removal efficiency reached to 84.1% at influent TP concentration of 12.4 mg/L. DO in aerobic phase was an important factor affecting nutrient removal, and the optimal DO was about 3 mg/L. There was a small amount of denitrifying phosphorus accumulating organisms (DPAOs) in SBMBMBR which resulted from the anoxic microenvironment existed in the inner of the biofilm. Fluorescence in situ hybridization (FISH) results of microbes showed the composition and spatial structure of the microbial community in the reactor. Furthermore, sequencing batch mode operation was propitious to retard membrane fouling.

  11. Thermal removal of nitrogen species from wood waste containing urea formaldehyde and melamine formaldehyde resins

    International Nuclear Information System (INIS)

    The removal of nitrogen from wood board waste through a low temperature pyrolysis (523-573 K) is investigated with two analytical methods. The kinetic study of the thermal behaviour of wood board and of its components (wood, UF and MF resins) shows the feasibility of removing thermally nitrogen from wood board waste. Indeed, the range of temperatures associated with the degradation of wood is different from the one obtained for the degradation of UF and MF resin. Isothermal conditions enable the determination of a kinetic model for degradation of wood board and of its components and demonstrate that the thermal behaviour of wood board is not the reflection of the sum of its components' behaviour. FTIR analysis of gas products confirms the feasibility removing nitrogen thermally and enables the evaluation of the optimum treatment conditions (temperature/duration). Elementary analysis of the treated samples and study of their low heating value (LHV) enable to quantify the efficiency of the thermal treatment in terms of nitrogen removal and of energy recovery. Results show that around 70% of the initial nitrogen can be removed from the waste, and that the temperature of treatment (between 523 K and 573 K) does not influence the efficiency in terms of nitrogen removal. Nevertheless, the ratio Residual energy/Initial energy (between 76% and 90%) is improved with the lowest temperature of treatment

  12. Intensified nitrogen removal of constructed wetland by novel integration of high rate algal pond biotechnology.

    Science.gov (United States)

    Ding, Yi; Wang, Wei; Liu, Xingpo; Song, Xinshan; Wang, Yuhui; Ullman, Jeffrey L

    2016-11-01

    High rate algal pond (HRAP) was combined with constructed wetland (CW) to intensify nitrogen removal through optimizing nitrification and denitrification. Nitrification and denitrification process mainly depends on the oxygen content and carbon source level in CWs. Algal biomass was enriched in HRAP, and dissolved oxygen (DO) concentration was increased via photosynthesis. Algal debris increased COD as degradable bioresource. The results showed that HRAP-CW hybrid systems effectively promoted the nitrogen removal performance due to rich DO and COD. The extension of hydraulic retention time in HRAP significantly improved NH4-N and TN removals by 10.9% and 11.1% in hybrid systems, respectively. The highest NH4-N and TN removals in hybrid systems respectively reached 67.2% and 63.5%, which were significantly higher than those in single CW. The study suggested that the hybrid system had the application potentials in nitrogen removal from wastewater. PMID:27544265

  13. Nitrogen removal efficiency of iron-carbon micro-electrolysis system treating high nitrate nitrogen organic pharmaceutical wastewater

    Institute of Scientific and Technical Information of China (English)

    周健; 段送华; 陈垚; 胡斌

    2009-01-01

    The nitrate nitrogen removal efficiency of iron-carbon micro-electrolysis system was discussed in treating pharmaceutical wastewater with high nitrogen and refractory organic concentration. The results show that the granularity of fillings,pH,volume ratios of iron-carbon and gas-water,and HRT. have significant effects on the nitrogen removal efficiency of iron-carbon micro-electrolysis system. The iron-carbon micro-electrolysis system has a good removal efficiency of pharmaceutical wastewater with high nitrogen and refractory organic concentration when the influent TN,NH4+-N,NO3--N and BOD5/CODCr are 823 mg/L,30 mg/L,793 mg/L and 0.1,respectively,at the granularity of iron and carbon 0.425 mm,pH 3,iron-carbon ratio 3,gas-water ratio 5,HRT 1.5 h,and the removal rates of TN,NH4+-N and NO3--N achieve 51.5%,70% and 50.94%,respectively.

  14. Removing nitrogen and phosphorus from simulated wastewater using algal biofilm technique

    Institute of Scientific and Technical Information of China (English)

    Qun WEI; Zhiquan HU; Genbao LI; Bo XIAO; Hao SUN; Meiping TAO

    2008-01-01

    Algal biofilm technology is a new and advanced wastewater treatment method. Experimental study on removing nitrogen and phosphorus from simulated waste-water using algal biofilm under the continuous light of 3500 Lux in the batch and continuous systems was carried out in this paper to assess the performance of algal biofilm in removing nutrients. The results showed that the effect of removing nitrogen and phosphorus by algal biofilm was remarkable in the batch system. The removal efficiencies of total phosphorus (TP), total nitrogen (TN), ammonia-nitrogen (NH3-N), and chemical oxygen demand (COD) reached 98.17%, 86.58%, 91.88%, and 97.11%, respect-ively. In the continuous system, hydraulic retention time (HRT) of 4 days was adopted; the effects of removing TP, TN, NH3-N, and COD by algal biofilm were very stable. During a run of 24 days, the removal efficiencies of TP, TN, NH3-N, and COD reached 95.38%, 83.93%, 82.38%, and 92.31%, respectively. This study demonstrates the feasibility of removing nitrogen and phosphorus from simulated wastewater using algal biofilm.

  15. Contribution on the influence of steel ladle processing (LF) upon the nitrogen removal rate

    International Nuclear Information System (INIS)

    Nitrogen, which is present in the composition of steel either dissolved or as a gas, represents an element, which is generally unwanted, except for the cases when the aim is to obtain nitrides or to increase the austenitic domain in stainless steels. The paper shows the results obtained in increasing the nitrogen removal rate during the secondary treatment of steel meant for oil industry pipes, into a Ladle Furnace-type installation. The processed data allowed the determination of variation domains, respectively graphical and analytical correlations between the nitrogen removal rate and the parameters of the secondary treatment process (bubbling duration, steel temperature and argon pressure)

  16. Enhanced Nutrient Removal with Upflow Biological Aerated Filter for Reclaimed Water

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-dong; PENG Yong-zhen; WANG Shu-ying; ZHANG Yan-ping

    2007-01-01

    A two-stage upflow biological aerated filter was designed as an advanced treatment process to optimize the operating parameters and study the correlative factors influencing the efficiency of nitrification, denitrification and phosphorus removal. The experimental results showed that the final effluent of the two-stage upflow biofilter process operated in series could meet the stringent limits of the reclaimed water for the total nitrogen of 2mg/L, and total phosphorus of 0.3mg/L. The high treatment efficiency allowed the reactor operating at very high hydraulic loadings and reaching nearly complete nitrification and denitrification.

  17. Nitrogen removal characteristics of heterotrophic nitrification-aerobic denitrification by Alcaligenes faecalis C16

    Institute of Scientific and Technical Information of China (English)

    Yuxiang Liu; Yao Wang; Yi Li; Hua An; Yongkang Lv

    2015-01-01

    Alcaligenes faecalis C16 was found to have the ability to heterotrophically nitrify and aerobical y denitrify. In order to further understand its nitrogen removal ability and mechanism, the growth and ammonium removal response were investigated at different C/N ratios and ammonium concentrations in the medium with citrate and acetate as carbon source separately. Furthermore, experiments of nitrogen sources, production of nitrogen gas and enzyme assay were conducted. Results show that the bacterium converts NH4+-N and produces NH2OH during the growing phase and nitrite accumulation is its distinct metabolic feature. A. faecalis C16 is able to tolerate not only high ammonium concentration but also high C/N ratio, and the ammonium tolerance is associated with carbon source and C/N ratio. The nitrogen balance under different conditions shows that approximately 28%–45%of the initial ammonium is assimilated into the cells, 44%–60%is denitrified and several percent is converted to nitrification products. A. faecalis C16 cannot utilize hydroxylamine, nitrite or nitrate as the sole nitrogen source for growth. However, nitrate can be used when ammonium is simultaneously present in the medium. A possible pathway for nitrogen removal by C16 is suggested. The preliminary enzyme assay provides more evidence for this nitrogen removal pathway.

  18. Biological Nutrient Removal Model No. 2 (BNRM2): a general model for wastewater treatment plants.

    Science.gov (United States)

    Barat, R; Serralta, J; Ruano, M V; Jiménez, E; Ribes, J; Seco, A; Ferrer, J

    2013-01-01

    This paper presents the plant-wide model Biological Nutrient Removal Model No. 2 (BNRM2). Since nitrite was not considered in the BNRM1, and this previous model also failed to accurately simulate the anaerobic digestion because precipitation processes were not considered, an extension of BNRM1 has been developed. This extension comprises all the components and processes required to simulate nitrogen removal via nitrite and the formation of the solids most likely to precipitate in anaerobic digesters. The solids considered in BNRM2 are: struvite, amorphous calcium phosphate, hidroxyapatite, newberite, vivianite, strengite, variscite, and calcium carbonate. With regard to nitrogen removal via nitrite, apart from nitrite oxidizing bacteria two groups of ammonium oxidizing organisms (AOO) have been considered since different sets of kinetic parameters have been reported for the AOO present in activated sludge systems and SHARON (Single reactor system for High activity Ammonium Removal Over Nitrite) reactors. Due to the new processes considered, BNRM2 allows an accurate prediction of wastewater treatment plant performance in wider environmental and operating conditions. PMID:23552235

  19. High performance of nitrogen and phosphorus removal in an electrolysis-integrated biofilter.

    Science.gov (United States)

    Gao, Y; Xie, Y W; Zhang, Q; Yu, Y X; Yang, L Y

    2016-01-01

    A novel electrolysis-integrated biofilter system was developed in this study to evaluate the intensified removal of nitrogen and phosphorus from contaminated water. Two laboratory-scale biofilter systems were established, one with electrolysis (E-BF) and one without electrolysis (BF) as control. The dynamics of intensified nitrogen and phosphorus removal and the changes of inflow and outflow water qualities were also evaluated. The total nitrogen (TN) removal rate was 94.4% in our newly developed E-BF, but only 74.7% in the control BF. Ammonium removal rate was up to 95% in biofilters with or without electrolysis integration with an influent ammonium concentration of 40 mg/L, and the accumulation of nitrate and nitrite was much lower in the effluent of E-BF than that of BF. Thus electrolysis plays an important role in TN removal especially the nitrate and nitrite removal. Phosphorus removal was significantly enhanced, exceeding 90% in E-BF by chemical precipitation, physical adsorption, and flocculation of phosphorus because of the in situ formation of ferric ions by the anodizing of sacrificial iron anodes. Results from this study indicate that the electrolysis integrated biofilter is a promising solution for intensified nitrogen and phosphorus removal. PMID:27508376

  20. Biodegradation of tetramethylammonium hydroxide (TMAH) in completely autotrophic nitrogen removal over nitrite (CANON) process.

    Science.gov (United States)

    Chen, Shen-Yi; Lu, Li-An; Lin, Jih-Gaw

    2016-06-01

    This study conducted a completely autotrophic nitrogen removal over nitrite (CANON) process in a continuous anoxic upflow bioreactor to treat synthetic wastewater with TMAH (tetramethylammonium hydroxide) ranging from 200 to 1000mg/L. The intermediates were analyzed for understanding the metabolic pathway of TMAH biodegradation in CANON process. In addition, (15)N-labeled TMAH was used as the substrate in a batch anoxic bioreactor to confirm that TMAH was converted to nitrogen gas in CANON process. The results indicated that TMAH was almost completely biodegraded in CANON system at different influent TMAH concentrations of 200, 500, and 1000mg/L. The average removal efficiencies of total nitrogen were higher than 90% during the experiments. Trimethylamine (TMA) and methylamine (MA) were found to be the main biodegradation intermediates of TMAH in CANON process. The production of nitrogen gas with (15)N-labeled during the batch anaerobic bioreactor indicated that CANON process successfully converted TMAH into nitrogen gas. PMID:26879202

  1. Autotrophic Nitrogen Removal in a Membrane-Aerated Biofilm Reactor Under Continuous Aeration: A Demonstration

    DEFF Research Database (Denmark)

    Gilmore, Kevin R.; Terada, Akihiko; Smets, Barth F.;

    2013-01-01

    allowed anaerobic ammonium-oxidizing bacteria (AnaerAOB) to develop and be retained for > 250 days. Daily autotrophic nitrogen removal of 1.7 g N/m(2) (75% of influent N load) was achieved at an oxygen/nitrogen surface loading ratio of 2.2, with up to 85% of the influent N proceeding through Anaer......AOB. During early nitritation, nitrogen oxide (NO(g), NO2(g), and N2O(g)) emissions comprised up to 10% of the removed influent nitrogen, but emissions disappeared after proliferation of AnaerAOB. Microbial communities were radially stratified, with aerobic ammonium-oxidizing bacteria (AerAOB) colonizing...... elimination of gaseous nitrogen oxide emissions....

  2. Modelling and evaluation of nitrogen removal performance in subsurface flow and free water surface constructed wetlands.

    Science.gov (United States)

    Tunçsiper, B; Ayaz, S C; Akça, L

    2006-01-01

    With the aim of protecting drinking water sources in rural regions, pilot-scale subsurface water flow (SSF) and free water surface flow (FWS) constructed wetland systems were evaluated for removal efficiencies of nitrogenous pollutants in tertiary stage treated wastewaters (effluent from the Pasaköy biological nutrient removal plant). Five different hydraulic application rates and emergent (Canna, Cyperus, Typhia sp., Phragmites sp., Juncus, Poaceae, Paspalum and Iris) and floating (Pistia, Salvina and Lemna) plant species were assayed. The average annual NH4-N, NO3-N and organic-N treatment efficiencies were 81, 40 and 74% in SSFs and 76, 59 and 75% in FWSs, respectively. Two types of the models (first-order plug flow and multiple regression) were tried to estimate the system performances. Nitrification, denitrification and ammonification rate constants (k20) values in SSF and FWS systems were 0.898 d-1 and 0.541 d(-1), 0.486 d(-1) and 0.502 d(-1), 0.986 d(-1) and 0.908, respectively. Results show that the first-order plug flow model clearly estimates slightly higher or lower values than observed when compared with the other model. PMID:16889247

  3. Heterotrophic nitrogen removal by a newly-isolated alkalitolerant microorganism, Serratia marcescens W5.

    Science.gov (United States)

    Wang, Teng; Dang, Qifeng; Liu, Chengsheng; Yan, Jingquan; Fan, Bing; Cha, Dongsu; Yin, Yanyan; Zhang, Yubei

    2016-07-01

    A new microbe, Serratia marcescens W5 was successfully isolated. Its feasibility in purification of excessively nitrogen-containing wastewater was evaluated using inorganic nitrogen media. Single factor tests showed that W5 exhibited high ammonium removal rates (above 80%) under different culture conditions (pH 7-10, C/N ratios of 6-20, 15-35°C, 0-2.5% of salinity, respectively). Besides various organic carbon sources, W5 was able to utilize calcium carbonate with 28.05% of ammonium removed. Further experiments indicated that W5 was capable of resisting high-strength ammonium (1200mg/L) with the maximum removal rate of 514.13mgL(-1)d(-1). The nitrogen removal pathway of W5 was also tested, showing that both nitrite and nitrate were efficiently removed only in the presence of ammonium, with hydroxylamine as intermediate, which was different from the conventional nitrogen removal pathway. All the results verified that W5 was a good candidate for the purification of excessively nitrogenous wastewater. PMID:27043057

  4. Aerobic granular sludge for simultaneous accumulation of mineral phosphorus and removal of nitrogen via nitrite in wastewater.

    Science.gov (United States)

    Li, Yongmei; Zou, Jinte; Zhang, Lili; Sun, Jing

    2014-02-01

    Lab-scale experiments were conducted to investigate the aerobic granular sludge process for simultaneous phosphorus (P) accumulation by chemical precipitation and biological nitrogen removal via nitrite. The P-rich granules were successfully incubated in a sequencing batch reactor, in which simultaneous nitrification-denitrification occurred via nitrite. The average diameter of the P-rich granules was 2.47 mm and the P content in granules was much higher than that in other granular systems with enhanced biological phosphorus removal process. Filamentous bacteria (genus Thiothrix) in the granules and the long sludge retention time (30 d) of the granular system played a crucial role in accumulation of precipitated phosphate. X-ray diffraction analysis, scanning electron microscopy coupled with energy dispersive X-ray and the experimental design using response surface methodology confirmed that the main mineral patterns in P-rich granules were Ca-Mg phosphate and whitlockite. PMID:24388958

  5. Efficient Total Nitrogen Removal in an Ammonia Gas Biofilter through High-Rate OLAND

    DEFF Research Database (Denmark)

    De Clippeleir, Haydée; Courtens, Emilie; Mosquera, Mariela;

    2012-01-01

    .86 ± 0.04 kg N m–3 biofilter d–1 and an empty bed residence time of 14 s. After 45 days of operation a stable nitrogen removal rate of 0.67 ± 0.06 kg N m–3 biofilter d–1, an ammonia removal efficiency of 99%, a removal of 75–80% of the total nitrogen, and negligible NO/N2O productions were obtained at......Ammonia gas is conventionally treated in nitrifying biofilters; however, addition of organic carbon to perform post-denitrification is required to obtain total nitrogen removal. Oxygen-limited autotrophic nitrification/denitrification (OLAND), applied in full-scale for wastewater treatment, can...... therefore shows the appealing potential of the OLAND process to treat ammonia containing gaseous streams....

  6. Investigation of bacterial populations in a biological nutrient removal system

    OpenAIRE

    Kavanaugh, Rathi G.

    1991-01-01

    Bacterial populations proliferating in a pilot scale biological nutrient removal system (BNR) were studied. The objective of the research was to develop media and methods to identify bacterial populations in BNR systems. Samples were obtained from the last aerobic zone of a University of Cape Town (UCT)-type system. The most probable numbers (MPN) of bacteria in the samples were analyzed in liquid media containing volatile fatty acids as sole sources of carbon. Samples...

  7. Optimum operation conditions of nitrogen and phosphorus removal by a biofilm-activated-sludge system

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In the biofilm and activated sludge combined system, denitrifying bacteria attached on the fibrous carriers in the anoxic tank, while the sludge containing nitrifying and phosphorus removal bacteria was only recirculated between the aerobic and anaerobic tanks. Therefore, the factors affected and restricted nitrification, denitrification and phosphorus removal in a traditional A/A/O process were resolved. This paper describes the optimum operation conditions for nitrogen and phosphorus removal using this system.

  8. Micropollutant removal during biological wastewater treatment and a subsequent ozonation step

    Energy Technology Data Exchange (ETDEWEB)

    Schaar, Heidemarie, E-mail: hschaar@iwag.tuwien.ac.a [Institute of Water Quality, Resources and Waste Management, Vienna University of Technology, Karlsplatz 13/226, 1040 Vienna (Austria); Clara, Manfred; Gans, Oliver [Umweltbundesamt, Spittelauer Lande 5, 1090 Vienna (Austria); Kreuzinger, Norbert [Institute of Water Quality, Resources and Waste Management, Vienna University of Technology, Karlsplatz 13/226, 1040 Vienna (Austria)

    2010-05-15

    The design criteria for wastewater treatment plants (WWTP) and the sludge retention time, respectively, have a significant impact on micropollutant removal. The upgrade of an Austrian municipal WWTP to nitrogen removal (best available technology, BAT) resulted in increased elimination of most of the analyzed micropollutants. Substances, such as bisphenol-A, 17alpha-ethinylestradiol and the antibiotics erythromycin and roxithromycin were only removed after the upgrade of the WWTP. Nevertheless, the BAT was not sufficient to completely eliminate these compounds. Thus, a pilot scale ozonation plant was installed for additional treatment of the effluent. The application of 0.6 g O{sub 3} g DOC{sup -1} increased the removal of most of the micropollutants, especially for compounds that were not degraded in the previous biological process, as for example carbamazepine and diclofenac. These results indicated that the ozonation of WWTP effluent is a promising technology to further decrease emissions of micropollutants from the treatment process. - SRT is an important criterion for micropollutant removal in wastewater treatment and the application of ozone is suitable for further removal of micropollutants.

  9. Source Separation of Urine as an Alternative Solution to Nutrient Management in Biological Nutrient Removal Treatment Plants.

    Science.gov (United States)

    Jimenez, Jose; Bott, Charles; Love, Nancy; Bratby, John

    2015-12-01

    Municipal wastewater contains a mixture of brown (feces and toilet paper), yellow (urine), and gray (kitchen, bathroom and wash) waters. Urine contributes approximately 70-80% of the nitrogen (N), 50-70% of the phosphorus (P) load and 60-70% of the pharmaceutical residues in normal domestic sewage. This study evaluated the impact of different levels of source separation of urine on an existing biological nutrient removal (BNR) process. A process model of an existing biological nutrient removal (BNR) plant was used. Increasing the amount of urine diverted from the water reclamation facilities, has little impact on effluent ammonia (NH₃-N) concentration, but effluent nitrate (NO₃-N) concentration decreases. If nitrification is necessary then no reduction in the sludge age can be realized. However, a point is reached where the remaining influent nitrogen load matches the nitrogen requirements for biomass growth, and no residual nitrogen needs to be nitrified. That allows a significant reduction in sludge age, implying reduced process volume requirements. In situations where nitrification is required, lower effluent nitrate (NO₃-N) concentrations were realized due to both the lower influent nitrogen content in the wastewater and a more favorable nitrogen-to-carbon ratio for denitrification. The external carbon requirement for denitrification decreases as the urine separation efficiency increases due to the lower influent nitrogen content in the wastewater and a more favorable nitrogen-to-carbon ratio for denitrification. The effluent phosphorus concentration decreases when the amount of urine sent to water reclamation facilities is decreased due to lower influent phosphorus concentrations. In the case of chemical phosphate removal, urine separation reduces the amount of chemicals required. PMID:26652123

  10. Heterotrophic nitrogen removal by Acinetobacter sp. Y1 isolated from coke plant wastewater.

    Science.gov (United States)

    Liu, YuXiang; Hu, Tingting; Song, Yujie; Chen, Hongping; Lv, YongKang

    2015-11-01

    A strain of Acinetobacter sp. Y1, which exhibited an amazing ability to remove ammonium, nitrite and nitrate, was isolated from the activated sludge of a coking wastewater treatment plant. The aim of this work was to study the ability, influence factors and possible pathway of nitrogen removal by Acinetobacter sp. Y1. Results showed that maximum removal rate of NH4(+)-N by the strain was 10.28 mg-N/L/h. Carbon source had significant influence on the growth and ammonium removal efficiencies of strain Y1. Pyruvate, citrate and acetate were favourable carbon sources for the strain. Temperature, pH value and shaking speed could affect the growth and nitrogen removal ability. Nitrate or nitrite could be used as a sole nitrogen source for the growth and removed efficiently by the strain. N2 levels increased to 53.74%, 50.21% and 55.13% within 36 h when 100 mg/L NH4(+)-N, NO2(-)-N or NO3(-) -N was used as sole nitrogen source in the gas detection experiment. The activities of hydroxylamine oxidoreductase (HAO), nitrate reductase (NR) and nitrite reductase (NiR), which are key enzymes in heterotrophic nitrification and aerobic denitrification, were all detectable in the strain. Consequently, a possible pathway for ammonium removal by the strain was also suggested. PMID:25910961

  11. Removal of organic matter and nitrogen from distillery wastewater by a combination of methane fermentation and denitrification/nitrification processes

    Institute of Scientific and Technical Information of China (English)

    LI Jun; ZHANG Zhen-jia; LI Zhi-rong; HUANG Guang-yu; Naoki Abe

    2006-01-01

    The distillery wastewater of Guangdong Jiujiang Distillery, which is characteristic of containing high organic matters and rich total nitrogen, was treated by a combination of methane fermentation and denitrification/nitrification processes. 80% of COD in the raw wastewater was However, almost all the organic nitrogen in the raw wastewater was converted into ammonia by ammonification there. Ammonia and volatile fatty acids (VFA) remaining in the anaerobically treated wastewater were simultaneously removed utilizing VFA as an electron donor by denitrification occurring in the other EGSB reactor and nitrification using PEG-immobilized nitrifying bacteria with recirculation process. An aerobic biological contact oxidization reactor was designed between denitrification/nitrification reactor for further COD removal. With the above treatment system,18000-28000 mg/L of COD in raw wastewater was reduced to less than 100 mg/L. Also, ammonia in the effluent of the system was not detected and the system had a high removal rate for 900-1200 mg/L of TN in the raw wastewater, only leaving 400 mg/L of nitrate nitrogen.

  12. On-line controlling system for nitrogen and phosphorus removal of municipal wastewater in a sequencing batch reactor (SBR)

    Institute of Scientific and Technical Information of China (English)

    Jun LI; Yongjiong NI; Yongzhen PENG; Guowei GU; Jingen LU; Su WEI; Guobiao CHENG; Changjin OU

    2008-01-01

    The objectives of this study were to establish an on-line controlling system for nitrogen and phosphorus removal synchronously of municipal wastewater in a sequencing batch reactor (SBR). The SBR for municipal wastewater treatment was operated in sequences: filling, anaerobic, oxic, anoxic, oxic, settling and discharge. The reactor was equipped with on-line monitoring sensors for dissolved oxygen (DO), oxidation-reduction potential (ORP) and pH. The variation of DO, ORP and pH is relevant to each phase of biological process for nitrogen and phosphorus removal in this SBR. The characteristic points of DO, ORP and pH can be used to judge and control the stages of process that include: phosphate release by the turning points of ORP and pH; nitrification by the ammonia valley of pH and ammonia elbows of DO and ORP; denitrification by the nitrate knee of ORP and nitrate apex ofpH; phosphate uptake by the turning point ofpH; and residual organic carbon oxida-tion by the carbon elbows of DO and ORP. The controlling system can operate automatically for nitrogen and phosphorus efficiently removal.

  13. Nitrogen removal performance of intermittently aerated membrane bioreactor treating black water.

    Science.gov (United States)

    Hocaoglu, S Murat; Atasoy, E; Baban, A; Insel, G; Orhon, D

    2013-01-01

    The study investigated the effect of intermittent aeration on the nitrogen removal performance of a membrane bioreactor (MBR) treating black water. A pilot-scale MBR with an effective volume of 630 L operating as a sequencing batch reactor (SBR) with intermittent aeration was used in the experiments. Substrate feeding was limited to the initial non-aerated phase. The MBR unit was sustained at a steady state at a sludge age of 60 d with a biomass concentration of around 10,000 mg/L for 3 months. The treated black water could be characterized with an average COD of 950 mg/L and total nitrogen of 172 mg/L, corresponding to a low COD/N ratio of 5.5. The selected MBR scheme was quite effective, reducing COD down to 26 mg/L, providing effective nitrification and yielding a total oxidized nitrogen concentration under 10 mg N/L. The nitrogen removal performance was substantially better than the level predicted by process stoichiometry, due to multiple anoxic configuration inducing additional nitrogen removal. Dissolved oxygen profiles associated with the cyclic operation of the system suggested that the incremental nitrogen removal could be attributed to simultaneous nitrification-denitrification, a commonly observed mechanism in MBR systems sustained at high biomass concentrations. PMID:24527634

  14. Biological nitrogen fixation is not a major contributor to the nitrogen demand of a commercially growth South African sugarcane cultivar

    NARCIS (Netherlands)

    Hoefsloot, G.; Termorshuizen, A.J.; Watt, D.A.; Cramer, M.D.

    2005-01-01

    It has previously been reported that endophytic diazotrophic bacteria contribute significantly to the nitrogen budgets of some graminaceous species. In this study the contribution of biological nitrogen fixation to the N-budget of a South African sugarcane cultivar was evaluated using 15N natural ab

  15. Investigation of Nitrogen Removal Efficiency from Wastewater using Modified Anaerobic Baffled Reactor (MABR

    Directory of Open Access Journals (Sweden)

    H Ganjidoust

    2010-02-01

    Full Text Available "n "nBackgrounds and Objectives : Nitrogen compounds in wastewater are mainly in four types of organic, am- monia, nitrite and nitrate. Total nitrogen concentration in municipal wastewater is usually within 25 to 45 mg/L as nitrogen. The most important problem with nitrogen is its oxygen demand and human health effect."nMaterials and Methods: Anaerobic Baffled Reactor (ABR is a system in which baffles are used to direct  wastewater flow. During 9 months study, a 15 liter modified ABR (104*30*15 cm with eight baffled com- partments was used for nitrification-denitrification processes. In the seventh compartment, the wastewater was aerated to oxidize ammonia to nitrite and nitrate."nResults : Denitrification was done in the first four compartments with removal efficiency from 60 to 84 per- cent for nitrite and nitrate, respectively. During the shock loading study (4 times of the last influent, a sharp decrease in nitrogen removal rate was observed which was then returned to the previous efficiency after 11 days. Artificial neural network was used to evaluate and process the data in which the observed error in 10 patterns was less than 15 percent."nConclusion : Anaerobic baffled reactor with an influent of up to 200 mg/L has capability to remove total  nitrogen concentration to less than the standard level of Iranian Department of Environment of 50 mg/L as nitrate and 10 mg/L as nitrogen.

  16. Simultaneous removal of aniline, nitrogen and phosphorus in aniline-containing wastewater treatment by using sequencing batch reactor.

    Science.gov (United States)

    Jiang, Yu; Wang, Hongyu; Shang, Yu; Yang, Kai

    2016-05-01

    The high removal efficiencies of traditional biological aniline-degrading systems always lead to accumulation of ammonium. In this study, simultaneous removal of aniline, nitrogen and phosphorus in a single sequencing batch reactor was achieved by using anaerobic/aerobic/anoxic (A/O/A) operational process. The removal efficiencies of COD, NH4(+)-N, TN, TP were over 95.80%, 83.03%, 87.13%, 90.95%, respectively in most cases with 250mgL(-1) of initial aniline at 6h cycle when DO was 5.5±0.5mgL(-1). Aniline was able to be completely degraded when initial concentrations were less than 750mgL(-1). When DO increased, the removal rate of NH4(+)-N and TP slightly increased along with the moderate decrease of removal efficiencies of TN. The variation of HRT had obvious influence on removal performance of pollutants. The system showed high removal efficiencies of aniline, COD and nutrients during the variation of operating conditions, which might contribute to disposal of aniline-rich industrial wastewater. PMID:26906036

  17. The feasibility of using a two-stage autotrophic nitrogen removal process to treat sewage.

    Science.gov (United States)

    Ma, Bin; Zhang, Shujun; Zhang, Liang; Yi, Peng; Wang, Junmin; Wang, Shuying; Peng, Yongzhen

    2011-09-01

    The feasibility of using a two-stage autotrophic nitrogen removal process to treat sewage was examined in this study. The obtained results showed that total nitrogen (TN) could be efficiently removed by 88.38% when influent TN and chemical oxygen demand (COD) were 45.87 and 44.40 mg/L, respectively. In the first stage, nitritation was instantly achieved by the bioaugmentation strategy, and can be maintained under limited oxygen condition (below 0.2mg/L). The ratio of nitrite to ammonium in the effluent of the nitritation reactor can be controlled at approximate 1.0 by adjusting aeration rate. In the second stage, anammox was realized in the upflow anaerobic sludge blanket (UASB) reactor, where the total nitrogen removal rate was 0.40 kg Nm(-3)d(-1) under limited-substrate condition. Therefore, the organic matter in sewage can be firstly concentrated in biomass which could generate biogas (energy). Then, nitrogen in sewage could be removed in a two-stage autotrophic nitrogen removal process. PMID:21719278

  18. Simultaneous removal of COD and nitrogen using a novel carbon-membrane aerated biofilm reactor

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A membrane aerated biofilm reactor is a promising technology for wastewater treatment. In this study, a carbon-membrane aerated biofilm reactor (CMABR) has been developed, to remove carbon organics and nitrogen simultaneously from one reactor. The results showed that CMABR has a high chemical oxygen demand (COD) and nitrogen removal efficiency, as it is operated with a hydraulic retention time (HRT) of 20 h, and it also showed a perfect performance, even if the HRT was shortened to 12 h. In this period, the removal efficiencies of COD, ammonia nitrogen (NH4+-N), and total nitrogen (TN) reached 86%, 94%, and 84%, respectively. However,the removal efficiencies of NH4+-N and TN declined rapidly as the HRT was shortened to 8 h. This is because of the excessive growth of biomass on the nonwoven fiber and very high organic loading rate. The fluorescence in situ hybridization (FISH) analysis indicated that the ammonia oxidizing bacteria (AOB) were mainly distributed in the inner layer of the biofilm. The coexistence of AOB and eubacteria in one biofilm can enhance the simultaneous removal of COD and nitrogen.

  19. Characteristics of aerobic granule and nitrogen and phosphorus removal in a SBR

    Energy Technology Data Exchange (ETDEWEB)

    Wang Fen, E-mail: wangfen@tju.edu.cn [School of Environmental Science and Technology, Tianjin University, Tianjin 300072 (China); Lu Shan; Wei Yanjie [School of Environmental Science and Technology, Tianjin University, Tianjin 300072 (China); Ji Min, E-mail: jimin@tju.edu.cn [School of Environmental Science and Technology, Tianjin University, Tianjin 300072 (China)

    2009-05-30

    The performance of a sequencing batch reactor (SBR) seeded with aerobic granular sludge was studied. The lab-scale SBR treating domestic wastewater operated at a volumetric loading rate (VLR) of 0.75-3.41 kg COD/(m{sup 3} d). The granule stability was related to the organic loading, and high loading would be favorable for granule stability. Analysis of typical cycle showed that granular sludge had good ability to simultaneously remove nitrogen and phosphorus. Most organic substances were removed at the anaerobic stage. At the aerobic stage, simultaneous nitrification and denitrification (SND) happened with phosphorus absorption. The SBR had good removal performance for organic matter and phosphate. However, the total nitrogen (TN) removal performance was ordinary, with average removal efficiency of about 52%. Batch experiments indicated that increases of influent C/N ratio and a large percentage of granule in the sludge were conducive for SND in SBR.

  20. Characteristics of aerobic granule and nitrogen and phosphorus removal in a SBR

    International Nuclear Information System (INIS)

    The performance of a sequencing batch reactor (SBR) seeded with aerobic granular sludge was studied. The lab-scale SBR treating domestic wastewater operated at a volumetric loading rate (VLR) of 0.75-3.41 kg COD/(m3 d). The granule stability was related to the organic loading, and high loading would be favorable for granule stability. Analysis of typical cycle showed that granular sludge had good ability to simultaneously remove nitrogen and phosphorus. Most organic substances were removed at the anaerobic stage. At the aerobic stage, simultaneous nitrification and denitrification (SND) happened with phosphorus absorption. The SBR had good removal performance for organic matter and phosphate. However, the total nitrogen (TN) removal performance was ordinary, with average removal efficiency of about 52%. Batch experiments indicated that increases of influent C/N ratio and a large percentage of granule in the sludge were conducive for SND in SBR.

  1. Biochemical studies on certain biologically active nitrogenous compounds

    International Nuclear Information System (INIS)

    Certain biologically active nitrogenous compounds such as alkaloids are widely distributed in many wild and medicinal plants such as peganum harmala L. (Phycophyllaceae). However, less literature cited on the natural compounds was extracted from the aerial parts of this plant; therefore this study was conducted on harmal leaves using several solvents. Data indicated that methanol extract was the inhibitoriest effect against some pathogenic bacteria, particularly Streptococcus pyogenus. Chromatographic separation illustrated that presence of four compounds; the most active one was the third compound (3). Elementary analysis (C, H, N) revealed that the primary chemical structure of the active antibacterial compound (C3) was: C17 H21 N3 O7 S with molecular weight 411. Spectroscopic analysis proved that coninical structure was = 1- thioformyl, 8?- D glucoperanoside- Bis- 2, 3 dihydroisopyridino pyrrol. This new compound is represented as a noval ?- carboline alkaloid compound

  2. Integrated side-stream reactor for biological nutrient removal and minimization of sludge production.

    Science.gov (United States)

    Coma, M; Rovira, S; Canals, J; Colprim, J

    2015-01-01

    Integrated processes to reduce in situ the sludge production in wastewater treatment plants are gaining attention in order to facilitate excess sludge management. In contrast to post-treatments, such as anaerobic digestion which is placed between the activated sludge system and dewatering processes, integrated technologies are placed in the sludge return line. This study evaluates the application of an anoxic side-stream reactor (SSR) which creates a physiological shock and uncouples the biomass metabolism and diverts the activity from assimilation for biosynthesis to non-growth activities. The effect of this system in biological nutrient removal for both nitrogen and phosphorus was evaluated for the anaerobic, anoxic and aerobic reactors. The RedOx potential within the SSR was maintained at -150 mV while the sludge loading rate was modified by increasing the percentage of recycled activated sludge feed to the SSR (0 and 40% at laboratory scale and 0, 10, 50 and 100% at pilot scale). The use of the SSR presented a slight reduction of phosphorus removal but maintained the effluent quality to the required discharge values. Nitrogen removal efficiency increased from 75 to 86% while reducing the sludge production rate by 18.3%. PMID:25860709

  3. Performance of Conventional Activated Sludge to Remove Nitrogen Compounds from Tomato Factory Wastewater

    OpenAIRE

    Meghdad Pirsaheb; Kiomars Sharafi; Golchin Rostami; Serveh Hosainie

    2012-01-01

    Today discharge of raw or treated wastewater containing nutrients (nitrogen and phosphorus compounds) to the surface water causing an Utrification phenomenon, will be due to excessive growth of algae in the receptive water source. Each of the of wastewater treatment system, providing principled design and operation can be reduced nutrients to standard level [1]. The purpose of this study was to evaluate the efficacy of conventional activated sludge systems to remove nitrogen compounds from wa...

  4. Innovative process scheme for removal of organic matter, phosphorus and nitrogen from pig manure

    DEFF Research Database (Denmark)

    Karakashev, Dimitar Borisov; Schmidt, Jens Ejbye; Angelidaki, Irini

    2008-01-01

    blanket (UASB) reactor, partial oxidation), nitrogen (oxygen-limited autotrophic nitrification-denitrification, OLAND) and phosphorus (phosphorus removal by precipitation as struvite, PRS) from pig manure were tested. Results obtained showed that microfiltration was unsuitable for pig manure treatment...... with sequential separation by decanter centrifuge, post-digestion in UASB reactor, partial oxidation and finally OLAND process. This combination resulted in reduction of the total organic, nitrogen and phosphorus contents by 96%, 88%, and 81%, respectively....

  5. Nitrogen Removal from Digested Black Water by One-stage Partial Nitritation and Anammox

    DEFF Research Database (Denmark)

    Vlaeminck, S.E.; Terada, Akihiko; Smets, Barth F.;

    2009-01-01

    rate of ca. 700 mg N L-1 d(-1) was reached over the subsequent 5 months. Suppression of the nitrite oxidizing bacteria at free ammonia levels above 3 mg N L-1 resulted in a nitrogen removal efficiency of 76%. The favorable ratios of both organic and inorganic carbon to nitrogen guaranteed endured......-stage partial nitritation and anammox, which will allow a significant decrease in operational costs compared to conventional nitrification/denitrification....

  6. Integrated physicochemical and biological treatment process for fluoride and phosphorus removal from fertilizer plant wastewater.

    Science.gov (United States)

    Gouider, Mbarka; Mlaik, Najwa; Feki, Mongi; Sayadi, Sami

    2011-08-01

    The phosphate fertilizer industry produces highly hazardous and acidic wastewaters. This study was undertaken to develop an integrated approach for the treatment of wastewaters from the phosphate industry. Effluent samples were collected from a local phosphate fertilizer producer and were characterized by their high fluoride and phosphate content. First, the samples were pretreated by precipitation of phosphate and fluoride ions using hydrated lime. The resulting low- fluoride and phosphorus effluent was then treated with the enhanced biological phosphorus removal (EBPR) process to monitor the simultaneous removal of carbon, nitrogen, and phosphorus. Phosphorus removal included a two-stage anaerobic/aerobic system operating under continuous flow. Pretreated wastewater was added to the activated sludge and operated for 160 days in the reactor. The operating strategy included increasing the organic loading rate (OLR) from 0.3 to 1.2 g chemical oxygen demand (COD)/L.d. The stable and high removal rates of COD, NH4(+)-N, and PO4(3-)-P were then recorded. The mean concentrations of the influent were approximately 3600 mg COD/L, 60 mg N/L, and 14 mg P/L, which corresponded to removal efficiencies of approximately 98%, 86%, and 92%, respectively. PMID:21905410

  7. Biological methods of dye removal from textile effluents - A review

    Directory of Open Access Journals (Sweden)

    Archna *

    2012-08-01

    Full Text Available Textile dyes are molecules designed to impart permanent colours to textile fabrics. They pose an environmental problem due to their toxicity and decrease the aesthetic value of water bodies into which they are discharged. Current physico-chemical technologies for dye removal cannot remove all classes of dyes, and two or more technologies are usually combined to achieve satisfactory decolourisation efficiencies. Direct biological treatment using fungi or bacteria can also be employed, but nutritional and physiological requirements of microorganisms put constraints on the applicability of such bioremediation processes. The search for efficient and green oxidation technologies has increased the interest in the use of enzymes to replace the conventional non-biological methods. Among the different existing oxidant enzymes, laccase (benzenediol:oxygen oxidoreductases; EC 1.10.3.2 has been the subject of intensive research in the past few decades due to its low substrate specificity. Enzymatic treatment using laccase can be simpler and much more efficient than the traditional physical or chemical treatments. This paper reviews conventional biological processes as well as  laccase-based processes might replace the traditionally energy intensive and water-consuming chemical treatment operations in the textile industry. Keywords: Dyes, Decolourisation, Green Oxidation, Laccase, Textile industry  

  8. Removal design report for the 108-F Biological Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    Most of the 100-F facilities were deactivated with the reactor and have since been demolished. Of the dozen or so reactor-related structures, only the 105-F Reactor Building and the 108-F Biology Laboratory remain standing today. The 108-F Biology Laboratory was intended to be used as a facility for the mixing and addition of chemicals used in the treatment of the reactor cooling water. Shortly after F Reactor began operation, it was determined that the facility was not needed for this purpose. In 1949, the building was converted for use as a biological laboratory. In 1962, the lab was expanded by adding a three-story annex to the original four-story structure. The resulting lab had a floor area of approximately 2,883 m{sup 2} (main building and annex) that operated until 1973. The building contained 47 laboratories, a number of small offices, a conference room, administrative section, lunch and locker rooms, and a heavily shielded, high-energy exposure cell. The purpose of this removal design report is to establish the methods of decontamination and decommissioning and the supporting functions associated with facility removal and disposal.

  9. Removal of nitrite impurity from nitrate labeled with nitrogen-15

    International Nuclear Information System (INIS)

    Potassium nitrate labeled with 15N is often used as a tracer in studies of N dynamics in soil and water systems. Typically, 0.8% NO2- impurity has been found in the batches of K15NO3 enriched to 99 atom % excess 15N that were purchased by our laboratory. Nitrite is an intermediate in several N cycling processes so its addition when adding NO3- could produce misleading results. We have developed a safe, simple, and inexpensive method to remove NO2- impurity from any NO3- solution in a water matrix. The principle is the oxidation of NO2- to NO3- by UV light in the presence of a heterogenous TiO2 catalyst. A NO2- concentration of 0.2 mM in 100 mL of 0.2 M NO3- solution could be oxidized in 12 min using 0.5 g L-1 TiO2 in a specially constructed photoreactor with a 75-W UV facial tanning lamp. For the routine removal of NO2-, use of the same TiO2 concentration in a standard beaker worked equally well when the irradiation time was extended to 2.5 h. After irradiation, the TiO2 is easily and totally removed from the solution by membrane filtration. (author)

  10. Ammonium nitrogen removal from coking wastewater by chemical precipitation recycle technology.

    Science.gov (United States)

    Zhang, Tao; Ding, Lili; Ren, Hongqiang; Xiong, Xiang

    2009-12-01

    Ammonium nitrogen removal from wastewater has been of considerable concern for several decades. In the present research, we examined chemical precipitation recycle technology (CPRT) for ammonium nitrogen removal from coking wastewater. The pyrolysate resulting from magnesium ammonium phosphate (MAP) pyrogenation in sodium hydroxide (NaOH) solution was recycled for ammonium nitrogen removal from coking wastewater. The objective of this study was to investigate the conditions for MAP pyrogenation and to characterize of MAP pyrolysate for its feasibility in recycling. Furthermore, MAP pyrolysate was characterized by scanning electron microscope (FESEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) as well as X-ray diffraction (XRD). The MAP pyrolysate could be produced at the optimal condition of a hydroxyl (OH(-)) to ammonium molar ratio of 2:1, a heating temperature of 110 degrees C, and a heating time of 3h. Surface characterization analysis indicated that the main component of the pyrolysate was amorphous magnesium sodium phosphate (MgNaPO(4)). The pyrolysate could be recycled as a magnesium and phosphate source at an optimum pH of 9.5. When the recycle times were increased, the ammonium nitrogen removal ratio gradually decreased if the pyrolysate was used without supplementation. When the recycle times were increased, the ammonium nitrogen removal efficiency was not decreased if the added pyrolysate was supplemented with MgCl(2).6H(2)O plus Na(2)HPO(4).12H(2)O during treatment. A high ammonium nitrogen removal ratio was obtained by using pre-formed MAP as seeding material. PMID:19850316

  11. Atrazine removal from aqueous solutions using submerged biological aerated filter.

    Science.gov (United States)

    Baghapour, Mohammad Ali; Nasseri, Simin; Derakhshan, Zahra

    2013-01-01

    Atrazine is widely used in the agriculture as an herbicide. Due to its high mobility, Atrazine leaks into the groundwaters, surface waters, and drinking water wells. Many physical and chemical methods have been suggested for removing Atrazine from aquatic environments. However, these methods are very costly, have many performance problems, produce a lot of toxic intermediates which are very harmful and dangerous, and cannot completely mineralize Atrazine. In this study, biodegradation of Atrazine by microbial consortium was evaluated in the aquatic environment. In order to assess the Atrazine removal from the aquatic environment, submerged biological aerated filter (SBAF) was fed with synthetic wastewater based on sucrose and Atrazine at different hydraulic retention times (HRTs). The maximum efficiencies for Atrazine and Soluble Chemical Oxygen Demand (SCOD) removal were 97.9% and 98.9%, respectively. The study findings showed that Stover-Kincannon model had very good fitness (R2 > 99%) in loading Atrazine in the biofilter and by increasing the initial concentration of Atrazine, the removal efficiency increased. Aerobic mixed biofilm culture was observed to be suitable for the treatment of Atrazine from aquatic environment. There was no significant inhibition effect on mixed aerobic microbial consortia. Atrazine degradation depended on the strength of wastewater and the amount of Atrazine in the influent. PMID:24499572

  12. Atrazine Removal from Aqueous Solutions using Submerged Biological Aerated Filter

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Baghapour

    2013-06-01

    Full Text Available Atrazine is widely used in the agriculture as an herbicide. Due to its high mobility, Atrazine leaks into the groundwaters, surface waters, and drinking water wells. Many physical and chemical methods have been suggested for removing Atrazine from aquatic environments. However, these methods are very costly, have many performance problems, produce a lot of toxic intermediates which are very harmful and dangerous, and cannot completely mineralize Atrazine. In this study, biodegradation of Atrazine by microbial consortium was evaluated in the aquatic environment. In order to assess the Atrazine removal from the aquatic environment, submerged biological aerated filter (SBAF was fed with synthetic wastewater based on sucrose and Atrazine at different hydraulic retention times (HRTs. The maximum efficiencies for Atrazine and Soluble Chemical Oxygen Demand (SCOD removal were 97.9% and 98.9%, respectively. The study findings showed that Stover-Kincannon model had very good fitness (R2 > 99% in loading Atrazine in the biofilter and by increasing the initial concentration of Atrazine, the removal efficiency increased. Aerobic mixed biofilm culture was observed to be suitable for the treatment of Atrazine from aquatic environment. There was no significant inhibition effect on mixed aerobic microbial consortia. Atrazine degradation depended on the strength of wastewater and the amount of Atrazine in the influent

  13. Intensified nitrogen removal in immobilized nitrifier enhanced constructed wetlands with external carbon addition.

    Science.gov (United States)

    Wang, Wei; Ding, Yi; Wang, Yuhui; Song, Xinshan; Ambrose, Richard F; Ullman, Jeffrey L

    2016-10-01

    Nitrogen removal performance response of twelve constructed wetlands (CWs) to immobilized nitrifier pellets and different influent COD/N ratios (chemical oxygen demand: total nitrogen in influent) were investigated via 7-month experiments. Nitrifier was immobilized on a carrier pellet containing 10% polyvinyl alcohol (PVA), 2.0% sodium alginate (SA) and 2.0% calcium chloride (CaCl2). A batch experiment demonstrated that 73% COD and 85% ammonia nitrogen (NH4-N) were degraded using the pellets with immobilized nitrifier cells. In addition, different carbon source supplement strategies were applied to remove the nitrate (NO3-N) transformed from NH4-N. An increase in COD/N ratio led to increasing reduction in NO3-N. Efficient nitrification and denitrification promoted total nitrogen (TN) removal in immobilized nitrifier biofortified constructed wetlands (INB-CWs). The results suggested that immobilized nitrifier pellets combined with high influent COD/N ratios could effectively improve the nitrogen removal performance in CWs. PMID:27396293

  14. Simultaneous removal of nitrogen oxide/nitrogen dioxide/sulfur dioxide from gas streams by combined plasma scrubbing technology

    Energy Technology Data Exchange (ETDEWEB)

    Moo Been Chang; How Ming Lee; Feeling Wu; Chi Ren Lai [National Central University (Taiwan). Graduate Institute of Environmental Engineering

    2004-08-01

    Nitrogen oxides (NOx)and sulfur dioxide (SO{sub 2}) are removed individually in traditional air pollution control technologies. This study proposes a combined plasma scrubbing (CPS) system for the simultaneous removal of SO{sub 2} and NOx. CPS consists of a dielectric barrier discharge (DBD) and wet scrubbing in series. DBD is used to generate nonthermal plasmas for converting NO to NO{sub 2}. The water-soluble NO{sub 2} then can be removed by wet scrubbing accompanied with SO{sub 2} removal. In this work, CPS was tested with simulated exhausts in the laboratory and with diesel generator exhausts in the field. Experimental results indicate that DBD is very efficient in converting NO to NO{sub 2}. More than 90% removal of NO, NOx, and SO{sub 2} can be simultaneously achieved with CPS. Both sodium sulfide (Na2S) and sodium sulfite (Na2SO3) scrubbing solutions are good for NO{sub 2} and SO{sub 2} absorption. Energy efficiencies for NOx and SO{sub 2} removal are 17 and 18 g/kWh, respectively. The technical feasibility of CPS for simultaneous removal of NO, NO{sub 2}, and SO{sub 2} from gas streams is successfully demonstrated in this study. However, production of carbon monoxide as a side-product is found and should be considered. 57 refs., 7 figs., 7 tabs.

  15. [Short or Long-Term Influence of Phenol on Nitrogen Removal Efficiency of ANAMMOX Sludge].

    Science.gov (United States)

    Yang, Peng-bing; Li, Xiang; Huang, Yong; Zhu, Liang; Cui, Jian-hong; Xu, Shan-shan

    2015-10-01

    The effects of phenol concentration on nitrogen removal efficiency in ANAMMOX sludge were studied in short or long-term. The nitrogen removal rate decreased rapidly with the increase of concentration of phenol in short-term. When the phenol concentration was above 600 mg x L(-1), the removal rate of NH4(+) -N was lower than 6% and the removal rate of TN was only about 10%. The long-term experimental results showed when the phenol concentration was below 100 mg x L(-1), the removal rate of NH4(+) -N can reach 99%, which indicated that ANAMMOX bacteria have a process of adaptation to the low concentration of phenol. However, when the phenol concentration was above 400 mg x L(-1), the removal rate of NH4(+) -N and TN was only 23.59% and 50.3%, the activity in sludge was significantly inhibited which was similarly to the short-term and the activity of denitrifying bacteria was significantly higher than ANAMMOX bacteria. As an organic carbon source, phenol can activated denitrification reaction and finally plays a dominant role in the system. However, the high concentration of phenol (1 000 mg x L(-1)) also has an inhibitory effect on denitrification bacteria. Half inhibitory concentration (IC50) of phenol to ANAMMOX activity was 71.57 mg x L(-1) by fitting. After 18 days' recovery, the stoichiometric ratios of nitrogen were changed, although the NH4(+) -N was basicly removed. The ratio of removed NH4(+) -N, reomved NO2(-) -N and produced NO3(-) -N was 1: 0.86: 0.2. Our results showed that the concentration of phenol should be controlled within a reasonable range, so that the reactor can achieve simultaneous removal of phenol and nitrogen. PMID:26841611

  16. Investigating the Efficiency of Biological Filters for Ammonia Removal

    Directory of Open Access Journals (Sweden)

    S Motesaddi Zarandi, MR Massoudinejad, A Mazaheri Tehrani, H Pouri

    2013-09-01

    Full Text Available Backgrounds and Aims: Ammonia removal from air to prevent severe damage to the environment and living organisms is very important. Biofiltration is an efficient, easy, cost-effective, and environmentally friendly process for degradation of ammonia from waste air. The aim of this study is to investigate the efficiency of biological filtration using a compost and scallop bed for ammonia removal. Materials and Methods: According to the ammonia removal method a column with 14cm inner diameter and 45cm height made from transparent Plexiglas was used. The column was filled up to 25 cm with compost and scallop (with a scallop: compost ratio of 1:4. In this study, performance of the biofilter was studied under 10 different flow rates (1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 lit/min and 5 different concentrations (0-20, 20-40, 40-60, 60-80 and 80-100 ppm at a temperature of 25 degrees Celsius. Results: The results of this study showed that efficiency is decreased when the flow rate or concentration is increased because the microbial population is reduced. The efficiency was reduced by 84.6-98.2 percent. Maximum efficiency occurred at a 0.19g/(m3.h loading rate. Efficiency was in 0-20 concentration intervals at a flow rate of 1 lit/min and at an Empty Bed Residence Time (EBRT of 240 seconds. Conclusion: The results show that a biofilter with a compost and scallop bed is efficient for ammonia removal from air. Results can be optimized in the design and operation of biological systems to be used in the industrial control of ammonia gas.

  17. Environmental distribution and population biology of Candidatus Accumulibacter, a primary agent of Biological Phosphorus Removal

    OpenAIRE

    Peterson, S. Brook; Warnecke, Falk; Madejska, Julita; McMahon, Katherine D.; Hugenholtz, Philip

    2008-01-01

    Members of the uncultured bacterial genus Candidatus Accumulibacter are capable of intracellular accumulation of inorganic phosphate (Pi) in activated sludge wastewater treatment plants (WWTPs) performing enhanced biological phosphorus removal (EBPR), but were also recently shown to inhabit freshwater and estuarine sediments. Additionally, metagenomic sequencing of two bioreactor cultures enriched in Candidatus Accumulibacter, but housed on separate continents, revealed the potential for glob...

  18. BIOLOGY OF POLYPHOSPHATE-ACCUMULATING BACTERIA INVOLVED IN ENHANCED BIOLOGICAL PHOSPHORUS REMOVAL

    NARCIS (Netherlands)

    KORTSTEE, GJJ; APPELDOORN, KJ; BONTING, CFC; VANNIEL, EWJ; VANVEEN, HW

    1994-01-01

    Recent research on the process of biological phosphorus removal in lab-scale treatment systems has indicated that: (i) the development of an actively polyP-accumulating bacterial community after the introduction of an anaerobic period may take at least 4 months; (ii) up to 80% of all aerobic bacteri

  19. An efficient process for wastewater treatment to mitigate free nitrous acid generation and its inhibition on biological phosphorus removal

    OpenAIRE

    Zhao, Jianwei; Wang, Dongbo; Li, Xiaoming; Yang, Qi; Chen, Hongbo; Zhong, Yu; An, Hongxue; Zeng, Guangming

    2015-01-01

    Free nitrous acid (FNA), which is the protonated form of nitrite and inevitably produced during biological nitrogen removal, has been demonstrated to strongly inhibit the activity of polyphosphate accumulating organisms (PAOs). Herein we reported an efficient process for wastewater treatment, i.e., the oxic/anoxic/oxic/extended-idle process to mitigate the generation of FNA and its inhibition on PAOs. The results showed that this new process enriched more PAOs which thereby achieved higher ph...

  20. Chemically enhanced biological NOx removal from flue gases : nitric oxide and ferric EDTA reduction in BioDeNox reactors

    OpenAIRE

    Maas,, F.

    2005-01-01

    The emission of nitrogen oxides (NOx) to the atmosphere is a major environmental problem. To abate NOx emissions from industrial flue gases, to date, mainly chemical processes like selective catalytic reduction (SCR) are applied. All these processes require high temperatures (>300 °C) and expensive catalysts. Therefore, biological NOx removal techniques using denitrification may represent promising alternatives for the conventional SCR techniques. However, water based biofiltration require...

  1. Enhanced nitrogen removal in constructed wetlands: effects of dissolved oxygen and step-feeding.

    Science.gov (United States)

    Li, Fengmin; Lu, Lun; Zheng, Xiang; Ngo, Huu Hao; Liang, Shuang; Guo, Wenshan; Zhang, Xiuwen

    2014-10-01

    Four horizontal subsurface flow constructed wetlands (HSFCWs), named HSFCW1 (three-stage, without step-feeding), HSFCW2 (three-stage, with step-feeding), HSFCW3 (five-stage, without step-feeding) and HSFCW4 (five-stage, with step-feeding) were designed to investigate the effects of dissolved oxygen (DO) and step-feeding on nitrogen removal. High removal of 90.9% COD, 99.1% ammonium nitrogen and 88.1% total nitrogen (TN) were obtained simultaneously in HSFCW4 compared with HSFCW1-3. The excellent TN removal of HSFCW4 was due to artificial aeration provided sufficient DO for nitrification and the favorable anoxic environment created for denitrification. Step-feeding was a crucial factor because it provided sufficient carbon source (high COD: nitrate ratio of 14.3) for the denitrification process. Microbial activities and microbial abundance in HSFCW4 was found to be influenced by DO distribution and step-feeding, and thus improve TN removal. These results suggest that artificial aeration combined with step-feeding could achieve high nitrogen removal in HSFCWs. PMID:25069093

  2. Effects of Invasive-Plant Management on Nitrogen-Removal Services in Freshwater Tidal Marshes.

    Science.gov (United States)

    Alldred, Mary; Baines, Stephen B; Findlay, Stuart

    2016-01-01

    Establishing relationships between biodiversity and ecosystem function is an ongoing endeavor in contemporary ecosystem and community ecology, with important practical implications for conservation and the maintenance of ecosystem services. Removal of invasive plant species to conserve native diversity is a common management objective in many ecosystems, including wetlands. However, substantial changes in plant community composition have the potential to alter sediment characteristics and ecosystem services, including permanent removal of nitrogen from these systems via microbial denitrification. A balanced assessment of costs associated with keeping and removing invasive plants is needed to manage simultaneously for biodiversity and pollution targets. We monitored small-scale removals of Phragmites australis over four years to determine their effects on potential denitrification rates relative to three untreated Phragmites sites and adjacent sites dominated by native Typha angustifolia. Sediment ammonium increased following the removal of vegetation from treated sites, likely as a result of decreases in both plant uptake and nitrification. Denitrification potentials were lower in removal sites relative to untreated Phragmites sites, a pattern that persisted at least two years following removal as native plant species began to re-colonize treated sites. These results suggest the potential for a trade-off between invasive-plant management and nitrogen-removal services. A balanced assessment of costs associated with keeping versus removing invasive plants is needed to adequately manage simultaneously for biodiversity and pollution targets. PMID:26914688

  3. Removal of Nitrogen,Phosphorus,and Organic Pollutants From Water Using Seeding Type Immobilized Microorganisms

    Institute of Scientific and Technical Information of China (English)

    LIN WANG; LI-JING HUANG; LUO-JIA YUN; FEI TANG; JING-HUI ZHAO; YAN-QUN LIU; XIN ZENG; QI-FANG LUO

    2008-01-01

    Objective To study the possibility of removing nitrogen.phosphorus,and organic pollutants using seeding type immobilized microorganisms.Methods Lakes P and M in Wuhan were chosen as the objects to study the removal of nitrogen,phosphorus,and organic pollutants with the seeding type immobilized microorganisms.Correlations between the quantity ofheterotrophic bacteria and the total nitrogen(TN),total phosphorus(TP),and toml organic carbon(TOC)in the two lakes were studied.The dominant bacteria were detected.inoculated to the sludge and acclimated by increasing nitrogen,phosphorus and decreasing carbon source in an intermittent,time-controlled and fixed-quantity way.The bacteria were thenused to prepare the seeding type immobilized microorganisms,selecting diatomim as the adsorbent cairtier.The ability and influence factors of removing nitrogen,phosphorus,and organic pollutant from water samples by the seeding type immobilized microorganismswere studied.Results The coefficients of the heterotrophic bacterial quantity correlatedwith TOC,TP,and TN were 0.9143,0.8229,0.7954 in Lake P and 0.9168,0.7187,0.6022 in Lake M.Ton swains of dominant heterotrophic bacteria belonging to Pseudomonas,Coccus,Aeromonas,Bacillus,and Enterobateriaceae,separately,were isolated.The appropriate conditions for the seeding type immobilized microorgansims in purifying the water sample were exposure time=24h,pH=7.0-8.0.and quantity of the immobilized microorganisms=0.75-1g/50 mL.The removal rates of TOC,TP,and TN under the above conditions were 80.2%,81.6%,and 86.8%,respectively.Conclusion The amount of heterotrophic bacteria in the two lakes was correlatexl with TOC,TP, and TN.These bacteria could be acclimatized and prepared for the immobilizedmicroorganisms which could effectively remove nitrogen,phosphorus,and mixed organic pollutants in the water sample.

  4. Enhanced vadose zone nitrogen removal by poplar during dormancy.

    Science.gov (United States)

    Ausland, Hayden; Ward, Adam; Licht, Louis; Just, Craig

    2015-01-01

    A pilot-scale, engineered poplar tree vadose zone system was utilized to determine effluent nitrate (NO3(-)) and ammonium concentrations resulting from intermittent dosing of a synthetic wastewater onto sandy soils at 4.5°C. The synthetic wastewater replicated that of an industrial food processor that irrigates onto sandy soils even during dormancy which can leave groundwater vulnerable to NO3(-) contamination. Data from a 21-day experiment was used to assess various Hydrus model parameterizations that simulated the impact of dormant roots. Bromide tracer data indicated that roots impacted the hydraulic properties of the packed sand by increasing effective dispersion, water content and residence time. The simulated effluent NO3(-) concentration on day 21 was 1.2 mg-N L(-1) in the rooted treatments compared to a measured value of 1.0 ± 0.72 mg-N L(-1). For the non-rooted treatment, the simulated NO3(-) concentration was 4.7 mg-N L(-1) compared to 5.1 ± 3.5 mg-N L(-1) measured on day 21. The model predicted a substantial "root benefit" toward protecting groundwater through increased denitrification in rooted treatments during a 21-day simulation with 8% of dosed nitrogen converted to N2 compared to 3.3% converted in the non-rooted test cells. Simulations at the 90-day timescale provided similar results, indicating increased denitrification in rooted treatments. PMID:26030360

  5. Nitrogen and phosphorus removal in pilot-scale anaerobic-anoxic oxidation ditch system

    Institute of Scientific and Technical Information of China (English)

    PENG Yongzhen; HOU Hongxun; WANG Shuying; CUI Youwei; Zhiguo Yuan

    2008-01-01

    To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal(SNDPR),a whole course of SNDPR damage and recovery was studied in a pilot-scale,anaerobicanoxic oxidation ditch(OD),where the volumes of anaerobic zone,anoxic zone,and ditches zone of the OD system were 7,21,and 280L,respectively.The reactor was fed with municipal wastewater with a flow rate of 336 L/d.The concept of simultaneous nitrification and denitrification (SND)rate(rSND) was put forward to quantify SND.The results indicate that:(1)high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase,total nitrogen (TN) and total phosphate(TP) removal rates were 80%and 85%,respectively;(2)when the system was aerated excessively,the stability of SND was damaged,and rSND dropped from 80% to 20%or less;(3)the natural logarithm of the ratio of NOx to MJ4+ in the effluent had a linear correlation to oxidation-reduction potential (ORP);(4)when NO3- was less than 6 mg/L.high phosphorus removal efficiency could be achieved;(5)denitrifying phosphorus removal (DNPR) could take place in the anaerobic-anoxic OD system.The major innovation was that the SND rate was devised and quantified.

  6. Biological decontamination using high and reduced pressure nitrogen afterglows

    OpenAIRE

    Sarrette, Jean-Philippe; Cousty, Sarah; Clement, Frank; Canal Barnils, Cristina; Ricard, André

    2012-01-01

    Typical results quantifying the antibacterial efficiencies of high and reduced pressure nitrogen afterglows are presented, using the same microbiological protocol. In parallel, the diffusion of the nitrogen atoms through different polymer membranes is studied. Peer Reviewed

  7. Biological nutrients removal from the supernatant originating from the anaerobic digestion of the organic fraction of municipal solid waste.

    Science.gov (United States)

    Malamis, S; Katsou, E; Di Fabio, S; Bolzonella, D; Fatone, F

    2014-09-01

    This study critically evaluates the biological processes and techniques applied to remove nitrogen and phosphorus from the anaerobic supernatant produced from the treatment of the organic fraction of municipal solid waste (OFMSW) and from its co-digestion with other biodegradable organic waste (BOW) streams. The wide application of anaerobic digestion for the treatment of several organic waste streams results in the production of high quantities of anaerobic effluents. Such effluents are characterized by high nutrient content, because organic and particulate nitrogen and phosphorus are hydrolyzed in the anaerobic digestion process. Consequently, adequate post-treatment is required in order to comply with the existing land application and discharge legislation in the European Union countries. This may include physicochemical and biological processes, with the latter being more advantageous due to their lower cost. Nitrogen removal is accomplished through the conventional nitrification/denitrification, nitritation/denitritation and the complete autotrophic nitrogen removal process; the latter is accomplished by nitritation coupled with the anoxic ammonium oxidation process. As anaerobic digestion effluents are characterized by low COD/TKN ratio, conventional denitrification/nitrification is not an attractive option; short-cut nitrogen removal processes are more promising. Both suspended and attached growth processes have been employed to treat the anaerobic supernatant. Specifically, the sequencing batch reactor, the membrane bioreactor, the conventional activated sludge and the moving bed biofilm reactor processes have been investigated. Physicochemical phosphorus removal via struvite precipitation has been extensively examined. Enhanced biological phosphorus removal from the anaerobic supernatant can take place through the sequencing anaerobic/aerobic process. More recently, denitrifying phosphorus removal via nitrite or nitrate has been explored. The removal of

  8. Removal efficiency and balance of nitrogen in a recirculating aquaculture system integrated with constructed wetlands.

    Science.gov (United States)

    Zhong, Fei; Liang, Wei; Yu, Tao; Cheng, Shui P; He, Feng; Wu, Zhen B

    2011-01-01

    The nitrogen (N) balance for aquaculture is an important aspect, especially in China, and it is attributed to the eutrophication in many freshwater bodies. In recent years, constructed wetlands (CWs) have been widely used in wastewater treatment and ecosystem restoration. A recirculating aquaculture system (RAS) consisting of CWs and 4 fish ponds was set up in Wuhan, China. Channel catfish (Ictalurus punctatus) fingerlings were fed for satiation daily for 168 days with 2 diets containing 5.49 % and 6.53 % nitrogen, respectively. The objectives of this study were to investigate the N budget in the RAS, and try to find out the feasibility of controlling N accumulation in the fish pond. It is expected that the study can provide a mass balance for the fate of N in the eco-friendly treatment system to avoid eutrophication. The results showed that the removal rates of ammonia (NH(+)(4)-N), sum of nitrate & nitrite (NO(-)(X)-N), and total nitrogen (TN) by the CWs were 20-55%, 38-84 % and 39-57 %, respectively. Denitrification in the CWs was the main pathway of nitrogen loss (41.67 %). Nitrogen accumulation in pond water and sediment accounted for 3.39 % and 12.65 % of total nitrogen loss, respectively. The nitrogen removal efficiency and budget showed that the CW could be used to control excessive nitrogen accumulation in fish ponds. From the viewpoint of the nitrogen pollution control, the RAS combined with the constructed wetland can be applied to ensure the sustainable development for aquaculture. PMID:21644158

  9. Enhanced biological phosphorus removal with different carbon sources.

    Science.gov (United States)

    Shen, Nan; Zhou, Yan

    2016-06-01

    Enhanced biological phosphorus removal (EBPR) process is one of the most economical and sustainable methods for phosphorus removal from wastewater. However, the performance of EBPR can be affected by available carbon sources types in the wastewater that may induce different functional microbial communities in the process. Glycogen accumulating organisms (GAOs) and polyphosphate accumulating organisms (PAOs) are commonly found by coexisting in the EBPR process. Predominance of GAO population may lead to EBPR failure due to the competition on carbon source with PAO without contributing phosphorus removal. Carbon sources indeed play an important role in alteration of PAOs and GAOs in EBPR processes. Various types of carbon sources have been investigated for EBPR performance. Certain carbon sources tend to enrich specific groups of GAOs and/or PAOs. This review summarizes the types of carbon sources applied in EBPR systems and highlights the roles of these carbon sources in PAO and GAO competition. Both single (e.g., acetate, propionate, glucose, ethanol, and amino acid) and complex carbon sources (e.g., yeast extract, peptone, and mixed carbon sources) are discussed in this review. Meanwhile, the environmental friendly and economical carbon sources that are derived from waste materials, such as crude glycerol and wasted sludge, are also discussed and compared. PMID:27087523

  10. [Effect of gas-lift device on nitrogen removal efficiency of ANAMMOX reactor ].

    Science.gov (United States)

    Xiang, Li; Zhang, Da-lini; Huang, Yong; Chen, Zong-heng; Yuan, Yi

    2014-09-01

    The effect of air-lift device on the nitrogen removal efficiency of ANAMMOX reactor was studied by increasing the substrate concentration to improve nitrogen load rate and inoculate ANAMMOX sludge. The results showed that the effluent recirculation was achieved by using nitrogen gas produced from the ANAMMOX process as power in the air-lift room. With the increase of nitrogen removal rate, the rate of effluent recirculation was increased, which diluted influent substrate concentration and alleviated the inhibition of ANAMMOX bacteria,. After 183 d operation, the effluent NH4+ -N and NO2- -N concentrations were increased to 46. 3 mg L-1 and 53.21 mg.L-1, and the nitrogen removal rate was kept stable at 28.3 kg (m3.d)-1, when the influent NH4+ -N and NO2- -N concentrations were increased to 700 mg.L-1 and 840 mgL-1, respectively. The effluent recirculation system formed by gas-lift devices is an economic and effective solution to the inhibition caused by high substrate concentration in traditional reactor, meanwhile, the power consumption of the external reflux pump was reduced. PMID:25518664

  11. Nitrogen transformations and removal mechanisms in algal and duckweed stabilisation ponds

    NARCIS (Netherlands)

    Zimmo, O.

    2003-01-01

    This thesis describes the results of a comparative study of the performance of algae-based ponds (ABPs) and duckweed-based ponds (DBPs) for wastewater treatment, with emphasis on nitrogen transformations and removal mechanisms.Batch experiments simulating algae and duckweed ( Lemna gibba ) stabilisa

  12. Startup and oxygen concentration effects in a continuous granular mixed flow autotrophic nitrogen removal reactor.

    Science.gov (United States)

    Varas, Rodrigo; Guzmán-Fierro, Víctor; Giustinianovich, Elisa; Behar, Jack; Fernández, Katherina; Roeckel, Marlene

    2015-08-01

    The startup and performance of the completely autotrophic nitrogen removal over nitrite (CANON) process was tested in a continuously fed granular bubble column reactor (BCR) with two different aeration strategies: controlling the oxygen volumetric flow and oxygen concentration. During the startup with the control of oxygen volumetric flow, the air volume was adjusted to 60mL/h and the CANON reactor had volumetric N loadings ranging from 7.35 to 100.90mgN/Ld with 36-71% total nitrogen removal and high instability. In the second stage, the reactor was operated at oxygen concentrations of 0.6, 0.4 and 0.2mg/L. The best condition was 0.2 mgO2/L with a total nitrogen removal of 75.36% with a CANON reactor activity of 0.1149gN/gVVSd and high stability. The feasibility and effectiveness of CANON processes with oxygen control was demonstrated, showing an alternative design tool for efficiently removing nitrogen species. PMID:25965951

  13. Effects of HRT and water temperature on nitrogen removal in autotrophic gravel filter.

    Science.gov (United States)

    Xu, Jing-Hang; He, Sheng-Bing; Wu, Su-Qing; Huang, Jung-Chen; Zhou, Wei-Li; Chen, Xue-Chu

    2016-03-01

    Organic Carbon added to low ratio of carbon to nitrogen (C/N ratio) wastewater to enhance heterotrophic denitrification performance might lead to higher operating costs and secondary pollution. In this study, sodium thiosulfate (Na2S2O3) was applied as an electron donor for a gravel filter (one kind of constructed wetland) to investigate effects of hydraulic retention time (HRT) and water temperature on the nitrate removal efficiency. The results show that with an HRT of 12 h, the average total nitrogen (TN) removal efficiencies were 91% at 15-20 °C and 18% at 3-6 °C, respectively. When HRT increased to 24 h, the average TN removal increased accordingly to 41% at 3-6 °C, suggesting denitrification performance was improved by extended HRT at low water temperatures. Due to denitrification, 96% of added nitrate nitrogen (NO3(-)-N) was converted to nitrogen gas, with a mean flux of nitrous oxide (N2O) was 0.0268-0.1500 ug m(-2) h(-1), while 98.86% of thiosulfate was gradually converted to sulfate throughout the system. Thus, our results show that the sulfur driven autotrophic denitrification constructed wetland demonstrated an excellent removal efficiency of nitrate for wastewater treatment. The HRT and water temperature proved to be two influencing factors in this constructed wetland treatment system. PMID:26766357

  14. Performance of completely autotrophic nitrogen removal over nitrite process under different aeration modes and dissolved oxygen

    Institute of Scientific and Technical Information of China (English)

    Jinsong GUO; Guohong YANG; Fang FANG; Yu QIN

    2008-01-01

    In this study, three sequential batch biofilm reactors (SBBRs) were operated for 155 days to evaluate the performance of completely autotrophic nitrogen removal over nitrite (CANON) process under different aeration modes and dissolved oxygen (DO). Synthetic wastewater with 160-mg NH4+-N/L was fed into the reac-tors. In the continuously-aerated reactor, the efficiency of the ammonium nitrogen conversion and total nitrogen (TN) removal reached 80% and 70%, respectively, with DO between 0.8-1.0 mg/L. Whereas in the intermit-tently-aerated reactor, at the aeration/non-aeration ratio of 1.0, ammonium was always under the detection limit and 86% of TN was removed with DO between 2.0 2.5 mg/L during the aeration time. Results show that CANON could be achieved in both continuous and inter-mittent aeration pattern. However, to achieve the same nitrogen removal efficiency, the DO needed in the inter-mittently-aerated sequential batch biofilm reactor (SBBR) during the aeration period was higher than that in the continuously-aerated SBBR. In addition, the DO in the CANON system should be adjusted to the aeration mode, and low DO was not a prerequisite to CANON process.

  15. The water vapor nitrogen process for removing sodium from LMFBR components

    International Nuclear Information System (INIS)

    Application and operation of the Water Vapor-Nitrogen Process for removing sodium from LMFBR components is reviewed. Emphasis is placed on recent efforts to verify the technological bases of the process, to refine the values of process parameters and to ensure the utility of the process for cleaning and requalifying components. (author)

  16. Novel strategy of nitrogen removal from domestic wastewater using pilot Orbal oxidation ditch

    Institute of Scientific and Technical Information of China (English)

    GAO Shou-you; PENG Yong-zhen; WANG Shu-ying; YAN Jun

    2006-01-01

    A pilot-scale Orbal oxidation ditch was operated for 17 months to optimize nitrogen removal from domestic wastewater of average COD to total nitrogen ratio of 2.7, with particular concern about the roles of dissolved oxygen (DO), mixed liquor suspended solids (MLSS) and return activated sludge (RAS) recycle ratio. Remarkable simultaneous nitrification and denitrification (SND) was observed and mean total nitrogen (TN) removal efficiency up to 72.1% was steadily achieved, at DO concentration in the out, middle and inner channel of 0.1, 0.4 and 0.7 mg/L, respectively, with an average MLSS of 5.5 g/L and RAS recycle ratio of 150%. Although the out channel took the major role in TN removal, the role of middle channel should never be ignored. The denitrification potential could be fully developed under low DO, high MLSS with adequate RAS ratio. The sludge settleability was amazingly improved under low DO operation mode, and some explanations were tried. In addition, a series of simplified batch tests were done to determine whether novel microorganisms could make substantial contribution to the performance of nitrogen removal. The results indicated that the SND observed in this Orbal oxidation ditch was more likely a physical phenomenon.

  17. Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal*

    Science.gov (United States)

    Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

    2015-01-01

    The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49–5.99 g N/(kg MLVSS∙h) (MLVSS is mixed liquor volatile suspended solids) and 6.63–6.81 g N/(kg MLVSS∙h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes. PMID:25845364

  18. Benchmarking biological nutrient removal in wastewater treatment plants: influence of mathematical model assumptions.

    Science.gov (United States)

    Flores-Alsina, Xavier; Gernaey, Krist V; Jeppsson, Ulf

    2012-01-01

    This paper examines the effect of different model assumptions when describing biological nutrient removal (BNR) by the activated sludge models (ASM) 1, 2d & 3. The performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) benchmark wastewater treatment plant was compared for a series of model assumptions. Three different model approaches describing BNR are considered. In the reference case, the original model implementations are used to simulate WWTP1 (ASM1 & 3) and WWTP2 (ASM2d). The second set of models includes a reactive settler, which extends the description of the non-reactive TSS sedimentation and transport in the reference case with the full set of ASM processes. Finally, the third set of models is based on including electron acceptor dependency of biomass decay rates for ASM1 (WWTP1) and ASM2d (WWTP2). The results show that incorporation of a reactive settler: (1) increases the hydrolysis of particulates; (2) increases the overall plant's denitrification efficiency by reducing the S(NOx) concentration at the bottom of the clarifier; (3) increases the oxidation of COD compounds; (4) increases X(OHO) and X(ANO) decay; and, finally, (5) increases the growth of X(PAO) and formation of X(PHA,Stor) for ASM2d, which has a major impact on the whole P removal system. Introduction of electron acceptor dependent decay leads to a substantial increase of the concentration of X(ANO), X(OHO) and X(PAO) in the bottom of the clarifier. The paper ends with a critical discussion of the influence of the different model assumptions, and emphasizes the need for a model user to understand the significant differences in simulation results that are obtained when applying different combinations of 'standard' models. PMID:22466599

  19. Estimation of tomato leaf nitrogen content using continuum-removal spectroscopy analysis technique

    Science.gov (United States)

    Ding, Yongjun; Li, Minzan; Zheng, Lihua; Sun, Hong

    2012-11-01

    In quantitative analysis of spectral data, noises and background interference always degrades the accuracy of spectral feature extraction. Continuum-removal analysis enables the isolation of absorption features of interest, thus increasing the coefficients of determination and facilitating the identification of more sensible absorption features. The purpose of this study was to test continuum-removal methodology with Visual-NIR spectral data of tomato leaf. Through analyzing the correlation between continuum-removal spectrum and nitrogen content, 15 characteristics parameters reflected changing tendency of nitrogen content were chosen, which is at 335, 405, 500, 520, 540, 550, 560, 580, 620, 640, 683, 704, 720, 736 and 770 nm. Finally, the variance inflation analysis and stepwise regression method was used to develop the prediction model of the nitrogen content of tomato leaf. The result showed that the predicted model, which used the values of continuum-removal spectrum at 335 and 720nm as input variables, had high predictive ability, with R2 of 0.755. The root mean square errors of prediction using a leave-one-out cross validation method were 0.513. These results suggest that the continuum-removal spectroscopy analysis has better potential to diagnose tomato growth in greenhouse.

  20. Effects of nitrogen fertilization in cotton crop on Aphis gossypii Glover (Hemiptera: Aphididae) biology

    International Nuclear Information System (INIS)

    The cotton aphid, Aphis gossypii Glove, is one of the pests of cotton crop and its relation with the host seem to depend on the amount of nitrogen available to the plant. The biology of A. gossypii using different cotton nitrogen fertility regimes was studied under greenhouse conditions, in Dourados, MS. A completely randomized design with nine replications in a factorial scheme (2x4x2)+1 was used. Two nitrogen sources (sulphate of ammonium and urea), four doses of nitrogen (50, 100, 150 and 200 kg ha-1), two different times of nitrogen application and one additional treatment without nitrogen were taken as factors. The nymphal phases, the pre-reproductive, reproductive and pos-reproductive periods, longevity, the life cycle and fecundity of the cotton aphid were evaluated. The doses of nitrogen influenced the cotton aphid biology in both sources and times of application, favoring its development and fecundity. (author)

  1. Physico-chemical technologies for nitrogen removal from wastewaters: a review

    Directory of Open Access Journals (Sweden)

    Andrea G. Capodaglio

    2015-07-01

    Full Text Available The paper examines the main physico-chemical processes for nitrogen removal from wastewaters, considering both those that have been long known and still widely applied at the industrial scale, and those that are still at the research level. Special attention is paid to the latest technological developments, as well as to operational problems and fields of application. The processes considered are briefly summarized as follows: ammonia air and steam stripping; ammonia vacuum distillation; ammonia precipitation as struvite; ammonia and nitrate removal by selected ion exchange; breakpoint chlorination; chloramine removal by selected activated carbon; ammonia adsorption on charcoal; chemical reduction of nitrate; advanced oxidation processes to convert ammonia and organic-N into nitrogen gas or nitrate. Special attention is given to advanced oxidation processes, as great research efforts are currently addressed to their implementation. These specifically include ozonation, peroxon oxidation, catalytic wet air oxidation, photo-catalytic oxidation and electrochemical oxidation.

  2. Seasonal effect on ammonia nitrogen removal by constructed wetlands treating polluted river water in southern Taiwan

    International Nuclear Information System (INIS)

    A pilot-scale constructed wetland (CW) system, combining a free water surface wetland and a subsurface wetland in series, was used to purify highly polluted river water. The concentrations of constituents varied seasonally. The effects of season-dependent parameters, such as temperature, mass loading rate and inflow salinity, on the removal of ammonia nitrogen (AN) in the wetland system were examined at a constant hydraulic loading rate, based on data from June 1998 to February 2000. AN removal of the CW varied cyclically with the seasons. The removal efficiency and the first-order volumetric removal rate constant (kV) increased exponentially with water temperature, yielding a high temperature coefficient (θ). However, the mass removal rate decreased exponentially as temperature increased. These contradictory results made the actual effect of temperature uncertain. The inhibition of high water salinity on AN removal was also unclear because kV (as well as kV20) and mass removal rate were inversely proportional to salinity. However, mass loading rate (MLR) predominantly affected both the removal efficiency and the mass removal rate of AN, both of which were factors that explicitly determined seasonality. A power equation, kV20' α MLR-n, was proposed to correct the variation of the mass loading rate in estimating kV and thus in designing a constructed wetland. - Seasonal variation of mass loading rate predominantly affected ammonia removal of constructed wetlands

  3. Nitrogen removal in a single-chamber microbial fuel cell with nitrifying biofilm enriched at the air cathode

    KAUST Repository

    Yan, Hengjing

    2012-05-01

    Nitrogen removal is needed in microbial fuel cells (MFCs) for the treatment of most waste streams. Current designs couple biological denitrification with side-stream or combined nitrification sustained by upstream or direct aeration, which negates some of the energy-saving benefits of MFC technology. To achieve simultaneous nitrification and denitrification, without extra energy input for aeration, the air cathode of a single-chamber MFC was pre-enriched with a nitrifying biofilm. Diethylamine-functionalized polymer (DEA) was used as the Pt catalyst binder on the cathode to improve the differential nitrifying biofilm establishment. With pre-enriched nitrifying biofilm, MFCs with the DEA binder had an ammonia removal efficiency of up to 96.8% and a maximum power density of 900 ± 25 mW/m 2, compared to 90.7% and 945 ± 42 mW/m 2 with a Nafion binder. A control with Nafion that lacked nitrifier pre-enrichment removed less ammonia and had lower power production (54.5% initially, 750 mW/m 2). The nitrifying biofilm MFCs had lower Coulombic efficiencies (up to 27%) than the control reactor (up to 36%). The maximum total nitrogen removal efficiency reached 93.9% for MFCs with the DEA binder. The DEA binder accelerated nitrifier biofilm enrichment on the cathode, and enhanced system stability. These results demonstrated that with proper cathode pre-enrichment it is possible to simultaneously remove organics and ammonia in a single-chamber MFC without supplemental aeration. © 2012 Elsevier Ltd.

  4. From Earth to Space: Application of Biological Treatment for the Removal of Ammonia from Water

    Science.gov (United States)

    Pickering, Karen; Adam, Niklas; White, Dawn; Ghosh, Amlan; Seidel, Chad

    2014-01-01

    Managing ammonia is often a challenge in both drinking water and wastewater treatment facilities. Ammonia is unregulated in drinking water, but its presence may result in numerous water quality issues in the distribution system such as loss of residual disinfectant, nitrification, and corrosion. Ammonia concentrations need to be managed in wastewater effluent to sustain the health of receiving water bodies. Biological treatment involves the microbiological oxidation of ammonia to nitrate through a two-step process. While nitrification is common in the environment, and nitrifying bacteria can grow rapidly on filtration media, appropriate conditions, such as the presence of dissolved oxygen and required nutrients, need to be established. This presentation will highlight results from two ongoing research programs - one at NASA's Johnson Space Center, and the other at a drinking water facility in California. Both programs are designed to demonstrate nitrification through biological treatment. The objective of NASA's research is to be able to recycle wastewater to potable water for spaceflight missions. To this end, a biological water processor (BWP) has been integrated with a forward osmosis secondary treatment system (FOST). Bacteria mineralize organic carbon to carbon dioxide as well as ammonia-nitrogen present in the wastewater to nitrogen gas, through a combination of nitrification and denitrification. The effluent from the BWP system is low in organic contaminants, but high in total dissolved solids. The FOST system, integrated downstream of the BWP, removes dissolved solids through a combination of concentration-driven forward osmosis and pressure driven reverse osmosis. The integrated system testing planned for this year is expected to produce water that requires only a polishing step to meet potable water requirements for spaceflight. The pilot study in California is being conducted on Golden State Water Company's Yukon wells that have hydrogen sulfide odor

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

    Institute of Scientific and Technical Information of China (English)

    Reti Hai; Yiqun He; Xiaohui Wang; Yuan Li

    2015-01-01

    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.

  6. Stabilisation of Biological Phosphorus Removal from Municipal Wastewater

    DEFF Research Database (Denmark)

    Krühne, Ulrich

    The biological phosphorus removal (BPR) from wastewater has developed considerably during the last decades and is applied in many present wastewater treatment plants (WWTP) all over the world. The process performance and the control of the BPR are under the influences of daily and seasonal...... variations of the influent wastewater concentrations and are not yet always guaranteed. Even though the scientific knowledge and practical experience has reached a high level of understanding of the involved key-processes it is still necessary to apply chemical precipitation of phosphorus during the time...... have been performed on an alternating pilot plant, receiving municipal wastewater. The pilot plant is equipped with an automatic measurement system based on the flow injection analysis (FIA) principle. Continuos analysis of the ammonium (NH4-N), nitrate (as NOx-N) and phosphorus (PO4-P) was performed...

  7. [Biological evaluation of means for chemomechanical removal of carious dentine].

    Science.gov (United States)

    Chechina, G N; Vinnichenko, Iu A; Rudenko, O E

    2007-01-01

    Biological evaluation of the 1st domestically developed and produced preparation for chemomechanical removal of carious dentine Caricleans (firm "VladMiVa", Belgorod) was performed in the CRIS with the use of express techniques of the hemolytic activity (HA) and cytotoxic effect (CTE). It was established that according to HA data both gels of the Caricleans preparation were nontoxic. CTE of 2 gels was also determined on 2 cells lines - LECH (lung embryon cell human) and HeLa; higher sensitivity was received on HeLa cells, the toxic effect of gel #2 of the Caricleans preparation was higher. The received results allowed the authors come to the conclusion that taking into account high sensitivity, high specificity and high cost of the CTE-test not to recommend its use for evaluation of the preparations for short-term action in stomatology. PMID:17690636

  8. Effective Removal of Nitrogen and Phosphorus from Surface Water Using Constructed Comprehensive Floating Remediation Islands

    Science.gov (United States)

    Wang, M.; Bai, S.

    2008-12-01

    Nitrogen and phosphorus are the chief pollutants of our aquatic systems which may be resulted from different contamination sources and could cause serious environmental and ecological problems. For example, nitrate contamination of the water systems from agricultural practices may be contributing to the eutrophication of the Chesapeake Bay, Maryland, USA, degrading water quality and aquatic habitats. Effective approaches for removal of nitrogen and phosphorus from our aquatic systems, particularly from surface water, is called for imminently. An in-situ remediation measure by constructed floating remediation islands has been developed and tested through the field experiments recently. Four pilot-scale settings with the different components and structures were constructed and operated in parallel in which a new type of the constructed floating remediation islands with multi-layers of substrate fillers, called the constructed multi-layer comprehensive floating remediation island, was included. The contaminated water taken directly from a river containing richly nitrogen and phosphorus was used for those experiments. The experiment results obtained from the four different experiment settings were examined. It was noticed that the degradation rates of both nitrogen and phosphorus in water in the setting with the constructed multi-layer comprehensive floating remediation island was greater than those in others. The mean removal rate of phosphorous in the experiment setting with the constructed multi-layer comprehensive floating remediation island was considerably higher than the removal rates of phosphorous in the other three experiment settings.

  9. Biological nutrient removal by internal circulation upflow sludge blanket reactor after landfill leachate pretreatment.

    Science.gov (United States)

    Abood, Alkhafaji R; Bao, Jianguo; Abudi, Zaidun N

    2013-10-01

    The removal of biological nutrient from mature landfill leachate with a high nitrogen load by an internal circulation upflow sludge blanket (ICUSB) reactor was studied. The reactor is a set of anaerobic-anoxic-aerobic (A2/O) bioreactors, developed on the basis of an expended granular sludge blanket (EGSB), granular sequencing batch reactor (GSBR) and intermittent cycle extended aeration system (ICEAS). Leachate was subjected to stripping by agitation process and poly ferric sulfate coagulation as a pretreatment process, in order to reduce both ammonia toxicity to microorganisms and the organic contents. The reactor was operated under three different operating systems, consisting of recycling sludge with air (A2/O), recycling sludge without air (low oxygen) and a combination of both (A2/O and low oxygen). The lowest effluent nutrient levels were realised by the combined system of A2/O and low oxygen, which resulted in effluent of chemical oxygen demand (COD), NH3-N and biological oxygen demand (BOD5) concentrations of 98.20, 13.50 and 22.50 mg/L. The optimal operating conditions for the efficient removal of biological nutrient using the ICUSB reactor were examined to evaluate the influence of the parameters on its performance. The results showed that average removal efficiencies of COD and NH3-N of 96.49% and 99.39%, respectively were achieved under the condition of a hydraulic retention time of 12 hr, including 4 hr of pumping air into the reactor, with dissolved oxygen at an rate of 4 mg/L and an upflow velocity 2 m/hr. These combined processes were successfully employed and effectively decreased pollutant loading. PMID:24494501

  10. Enhanced nitrogen removal in single-chamber microbial fuel cells with increased gas diffusion areas

    KAUST Repository

    Yan, Hengjing

    2012-11-23

    Single-chamber microbial fuel cells (MFCs) with nitrifiers pre-enriched at the air cathodes have previously been demonstrated as a passive strategy for integrating nitrogen removal into current-generating bioelectrochemical systems. To further define system design parameters for this strategy, we investigated in this study the effects of oxygen diffusion area and COD/N ratio in continuous-flow reactors. Doubling the gas diffusion area by adding an additional air cathode or a diffusion cloth significantly increased the ammonia and COD removal rates (by up to 115% and 39%), ammonia removal efficiency (by up to 134%), the cell voltage and cathode potentials, and the power densities (by a factor of approximately 2). When the COD/N ratio was lowered from 13 to 3, we found up to 244% higher ammonia removal rate but at least 19% lower ammonia removal efficiency. An increase of COD removal rate by up to 27% was also found when the COD/N ratio was lowered from 11 to 3. The Coulombic efficiency was not affected by the additional air cathode, but decreased by an average of 11% with the addition of a diffusion cloth. Ammonia removal by assimilation was also estimated to understand the ammonia removal mechanism in these systems. These results showed that the doubling of gas diffusion area enhanced N and COD removal rates without compromising electrochemical performance. © 2012 Wiley Periodicals, Inc.

  11. Anammox bacteria community and nitrogen removal in a strip-like wetland in the riparian zone.

    Science.gov (United States)

    Pei, Yuansheng; Wang, Jun; Wang, Ziyuan; Tian, Binghui

    2011-01-01

    A strip-like wetland was constructed in the riparian zone for investigation of ammonium nitrogen (NH(3)-N) removal in the Peach River. An inner zeolite layer was set in the wetland to adsorb NH(3)-N and further to remove total nitrogen (TN). An oxygen-deficient condition with dissolved oxygen of 0.87-1.60 mg L(-1) was observed in the zeolite layer, which benefits anaerobic ammonium oxidation (anammox) bacteria survival. The community structure of anammox bacteria was analyzed in the zeolite layer. The analysis shows that the anammox bacterial sequences are grouped into three known distinct clusters: Candidatus Brocadia fulgida, Candidatus Brocadia anammoxidans and Candidatus Jettenia asiatica. The intensified test driven by artificial pumping shows that average removal rates of NH(3)-N and TN are 41.6 mg m(-3)d(-1) and 63.2 mg m(-3)d(-1), respectively. The normal test driven by natural hydrodynamics also verifies that NH(3)-N removal mainly happens in the zeolite layer. Microbial mechanism of TN removal in the wetland involves both the autotrophic and heterotrophic process. These results suggest that the strip-like RW can be a cost-effective approach for NH(3)-N removal and can potentially be extended to similar rivers as no extra energy is required to maintain the wetland operation. PMID:21644147

  12. Nitrogen removal by three types of bioretention columns under wetting and drying regimes

    Institute of Scientific and Technical Information of China (English)

    唐宁远; 李田

    2016-01-01

    The behaviors of inorganic nitrogen species in three types of bioretention columns under an intermittently wetting regime were investigated. The mean NH4+—N, NO3−—N and total N (TN) removal efficiencies for the conventional bioretention column (Col. T1) are 71%, 1% and 41%, for layered bioretention column with less permeable soil layer (Col. T2) the efficiencies are 83%, 84% and 82%, and for the bioretention column with submerged zone (Col. T3) the values are 63%, 31% and 53%, respectively. The best nitrogen removal is obtained using Col. T2 with relatively low infiltration rate. Adsorption during runoff dosing and nitrification during the drying period are the primary NH4+—N removal pathways. Less permeable soil and the elevated outlet promote the formation of anoxic conditions. 30%–70% of NO3−—N applied to columns in a single repetition is denitrified during the draining period, suggesting that the draining period is an important timeframe for the removal of NO3−—N. Infiltration rate controls the contact time with media during the draining periods, greatly influencing the NO3−—N removal effects. Bioretention systems with infiltration rate ranging from 3 to 7 cm/h have a great potential to remove NO3−—N.

  13. Nitrogen-Containing Apigenin Analogs: Preparation and Biological Activity

    Directory of Open Access Journals (Sweden)

    Jinyi Wang

    2012-12-01

    Full Text Available A series of nitrogen-containing apigenin analogs 4a–j was synthesized via Mannich reactions to develop anticancer, antibacterial, and antioxidant agents from plant-derived flavonoids. The chemical structures of these compounds were confirmed using 1H-NMR, 13C-NMR, and ESI-MS. The in vitro biological activities of the analogs were evaluated via assays of their antiproliferative, antibacterial, and antioxidant activities. The prepared apigenin analogs exhibited different antiproliferative activities against four human cancer cell lines, namely human cervical (HeLa, human hepatocellular liver (HepG2, human lung (A549, and human breast (MCF-7 cancer cells. Compound 4i showed the most favorable in vitro antiproliferative activity with IC50 values of 40, 40, 223, and 166 μg/mL against HeLa, HepG2, A549, and MCF-7, respectively. The 1,1-diphenyl-2-picrylhydrazyl (DPPH free radical scavenging activity assay also showed that 4i had the most potent antioxidant activity, with the smallest IC50 value (334.8 μg/mL. The antibacterial activities of the analogs were determined using a two-fold serial dilution technique against four pathogenic bacteria, namely Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. All the prepared apigenin analogs exhibited more potent activities than the parent apigenin. Compounds 4h and 4j, in particular, exhibited the best inhibitory activities against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis with MIC values of 3.91 and 1.95 μg/mL, respectively.

  14. Redox stratified biofilms to support completely autotrophic nitrogen removal: Principles and results

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Smets, Barth F.

    biofilm structure with aerobic ammonium oxidizing bacteria dominating the areas of the biofilm closer to the membrane surface while anaerobic oxidizing bacteria populated mainly the outer biofilm region. The biofilm was approximately 500 m thick and featured both aerobic and anaerobic ammonium oxidizing...... the outgrowth of nitrite oxidizing bacteria communities. Autotrophic nitrogen removal is already revealing itself as a cheap alternative to treat concentrated nitrogen streams. However, we believe that this concept can be taken a step further in MABRs and become an even more cost-effective, compact...

  15. Control structure design for resource recovery using the enhanced biological phosphorus removal and recovery (EBP2R) activated sludge process

    DEFF Research Database (Denmark)

    Valverde Perez, Borja; Fuentes-Martínez, José Manuel; Flores Alsina, Xavier;

    2016-01-01

    structurefor the novel enhanced biological phosphorus removal and recovery (EBP2R) process, which is currentlyunder development. The aim of the EBP2R is to maximize phosphorus recovery through optimal greenmicro-algal cultivation, which is achieved by controlling the nitrogen to phosphorus ratio (N-to-P ratio......Nowadays, wastewater is considered as a set of resources to be recovered rather than a mixture of pollutantsthat should be removed. Many resource recovery schemes have been proposed, involving the useof novel technologies whose controllability is poorly studied. In this paper we present a control...... in the effluent (16.9 ± 0.07) and can recover about 72% of the influent phosphorus. The phosphorus recovered by the CFS is limited by the influent nitrogen (65% of the influent phosphorus load). Using the CFS configuration the effluent N-to-P ratio cannot be effectively controlled (16.45 ± 2.48). Therefore...

  16. [Isolation of heterotrophic nitrifiers which can tolerate high concentration of ammonia-nitrogen and the optimization of their nitrogen removal efficiency in wastewater].

    Science.gov (United States)

    Si, Wen-Gong; Lü, Zhi-Gang; Xu, Chao

    2011-11-01

    The removal capabilities and tolerance of high concentration of ammonia-nitrogen of heterotrophic nitrifiers were studied. Methods included multi-point sampling, domestication, gradient dilution of domestication liquid, color indicator as rapid nitrification detection and isolation from streaking plate were conducted to screen heterotrophic nitrifiers. The strains were identified according to the sequence analysis of 16S rDNA. After inoculating the strains into ammonia-nitrogen wastewater, changes of nitrogen compounds were measured in order to understand their denitrification characteristics. The denitrification efficiency was optimized by improving the C/N ratio, changing the compatibility of the strains and mixing the compatible strains with the domesticated bacterial suspension. Finally 8 high-efficiency heterotrohic nitrifiers were obtained, and named as N1-N8 respectively. Phylogenetic analysis showed that 8 strains belonged to Comamonas genus, Rhodococcus genus, Pseudomonos genus, Arthrobacter genus and Paracoccus genus, respectively. When the initial concentration of ammonia nitrogen was 256.9 mg x L(-1) and the C/N was 5.5 of the artificial wastewater, the removal rates of ammonia nitrogen by the strains were about 65%-80%, and the stain N4 was the best. When the C/N ratio of the wastewater increased to 8.0, the ammonia nitrogen removal rates of the strains correspondingly increased to about 80% -90%. As the strains compatibility, the denitrification rate of N4 + N5 + N6 was 88.2% in the artificial wastewater with initial ammonia nitrogen concentration was 261.1 mg x L(-1) and initial C/N ratio was 5.5, which was higher than that of any single strain. The ammonia nitrogen removal rate could reach to 99.8% when N4 + N5 + N6 were combined with the domesticated bacterial suspension. In the artificial wastewater, when the initial ammonia nitrogen increased to 446.9 mg x L(-1) and the C/N ratio decreased to 3.2, the ammonia nitrogen removal rate of the mixed

  17. The nitrogen regime and biological fixation of nitrogen in moss communities (the Khibiny Mountains)

    Science.gov (United States)

    Egorov, V. I.

    2007-04-01

    In the vegetation belts of the Khibiny Mountains, the dynamics of the contents of mineral and easily hydrolyzable (according to Cornfield) nitrogen compounds in the litter and the nitrogen-fixing capacity of epiphytic cyanobacteria on dominant mosses were studied. The nitrogen regime of most moss species was shown to be self-supporting probably due to the intense assimilation of molecular nitrogen by epiphytic cyanobacteria (during the growing period, up to 28% of the total nitrogen content in plants) and the low organic matter production by mosses.

  18. Nitrogen Removal Improvement by Adding Peat in Deep Soil of Subsurface Wastewater Inifltration System

    Institute of Scientific and Technical Information of China (English)

    CHEN Pei-zhen; CUI Jian-yu; HU Lin; ZHENG Miao-zhuang; CHENG Shan-ping; HUANG Jie-wen; MU Kang-guo

    2014-01-01

    In order to enhance the nitrogen removal, a subsurface wastewater inifltration system (SWIS) was improved by adding peat in deep soil as carbon source for denitriifcation process. The effects of addition of carbon source in the underpart of the SWIS on nitrogen removal at different inlfuents (with the total nitrogen (TN) concentration 40 and 80 mg L-1, respectively) were investigated by soil column simulating experiments. When the relatively light pollution inlfuent with 40 mg L-1 TN was used, the average concentrations of NO3--N and TN in eflfuents were (4.69±0.235), (6.18±0.079) mg L-1, respectively, decreased by 32 and 30.8%than the control;the NO3--N concentration of all eflfuents was below the maximum contaminant level of 10 mg L-1;as high as 92.67%of the TN removal efifciency was achieved. When relatively heavy pollution inlfuent with 80 mg L-1 TN was used, the average concentrations of NO3--N and TN in eflfuents were (10.2±0.265), (12.5±0.148) mg L-1 respectively, decreased by 20 and 21.2%than the control;the NO3--N concentration of all eflfuents met the grade III of the national quality standard for ground water of China (GB/T 14848-1993) with the values less than 20 mg L-1;the TN removal efifciency of 94.1%was achieved. In summary, adding peat in the underpart of the SWIS signiifcantly decreased TN and NO3--N concentration in eflfuents and the nitrogen removal efifciency improved signiifcantly.

  19. Treatment of high strength leachate by biological nutrient removal processes

    International Nuclear Information System (INIS)

    This study describes the performance of a pilot-scale A/O system with respect to not only conventional wastewater quality parameters, but also specific volatile and semi-volatile organics. Hydraulic loadings were increased from 1.0 to 3.0 m3/d in two stages. The leachate was characterized by highly variable BOD, COD, TKN, and NH3-N concentrations ranging from 540-7185, 2040-8470, 501-1294, and 321-1000 mg/l respectively with over 91% of the BOD and 95% of the COD in soluble form. Concentrations of VOCs primarily benzene, chlorobenzene, ethylbenzene, toluene, o-xylene, m and p-xylene, 1,1-dichloroethane, and trichloroethylene ranging from 0.2 to 81.4 μg/l were reduced to below detection levels in the A/O system. At the three loadings investigated in the study i.e. 1, 2, and 3 m3 /d, the system affected excellent removals of organics and nitrogen, with reductions of soluble BOD (SBOD), total BOD, soluble COD (SCOD), COD, TKN, NH3-N, and total nitrogen of 91-100%, 87-97%, 65-93%, 57-91%, 84-96%, 99.96-99.97%, and 81-90% respectively. At the various loadings investigated in this study, effluent concentrations of SBOD, BOD,COD, SCOD, TKN, NH3-N, and nitrates as low as 4, 56, 685, 608, 35.2, 0.6, and 28.8 mg/l respectively were routinely achieved. Furthermore, despite operating at high mixed liquor solids in the 5000-6500 mg/l range, and the adversely long hydraulic residence time in the clarifier of 2 days, effluent total and volatile suspended solids concentrations of about 50 and 30 mg/l were achieved. The A/O system was not only capable of achieving the required sewer discharge criteria but it also demonstrated the achievability of surface discharge criteria, thus eliminating the need for additional treatment at the municipal wastewater treatment facilities. The system operated in a very stable fashion resisting the wide fluctuations in influent quality. (author)

  20. [Effect of reed rhizosphere on nitrogen and COD removal efficiency in subsurface flow constructed wetlands].

    Science.gov (United States)

    Dai, Yuan-yuan; Yang, Xin-ping; Zhou, Li-xiang

    2008-12-01

    Nitrogen removal efficiency was investigated in three subsurface flow constructed wetlands (CWs) with and without reed. Root bag made of nylon sieve with 300 mesh was used to enwrap the reed root in one of reed CWs to distinguish reed rhizosphere from non-rhizosphere. The CWs with root bag enwrapped reed root (hereinafter called as mesh CWs) and other CWs were fed with artificial ammonium-rich wastewater. The results indicated that the COD and N removal occurred mainly in the front of CWs, and C and nitrogen removal occurred concurrently along the stream way. When C/N ratio of influent was 5, the removal efficiencies of NH4+ -N in control CWs, reed CWs and mesh CWs were 66.2%, 94.2% and 82.2%, respectively. TN removal efficiencies were 67.2%, 90.7% and 76.1% respectively. Simultaneous nitrification and denitrification phenomenon in this study was also observed. The removal efficiency of organic carbon was different from nitrogen removal efficiency, mesh CWs showed the highest COD removal efficiency with 80.9%, while control CWs and reed CWs were 72.2% and 56.2%, respectively. C/N ratio of wastewater throughout the bed was more than 5 in three CWs, which indicated carbon source supply was enough for denitrification. The oxidation-reduction position (ORP) and concentration of total organic carbon in rhizosphere and non-rhizosphere were detected. The ORP in the front of mesh CWs's rhizosphere was much higher than that in control CWs and non-rhizosphere in mesh CWs, which were 11-311 mV and 62-261 mV, respectively. Root exudates also showed the difference between rhizosphere and non-rhizosphere in mesh CWs, the TOC of them were 21.3-54.6 mg x L(-1) and 6.65-12.0 mg x L(-1). Due to the higher ORP and concentration of TOC, the nitrogen removal efficiency in plant CWs was much higher than that in control CWs. PMID:19256373

  1. Assessment of the removal of estrogenicity in biological nutrient removal wastewater treatment processes

    International Nuclear Information System (INIS)

    The removal of estrogenicity in a University of Cape Town-biological nutrient removal (UCT-BNR) wastewater treatment process was investigated using pilot and bench scale systems, batch experiments and mathematical modeling. In the pilot BNR process, 96 ± 5% of the estrogenicity exerted by the influent wastewater was removed by the treatment process. The degradation efficiencies in the anaerobic, anoxic and aerobic zones of the pilot BNR bioreactor were 11 ± 9%, 18 ± 2% and 93 ± 10%, respectively. In order to further understand the performance of the BNR process in the removal of estrogenicity from wastewater, a bench scale BNR process was operated with synthetic wastewater dosed with E1 and E2. The removal of estrogenicity in the bench scale system (95 ± 5%) was comparable to the pilot BNR process and the degradation efficiencies were estimated to be 8 ± 0.8%, 38 ± 4% and 85 ± 22% in the anaerobic, anoxic and aerobic zones, respectively. A biotransformation model developed to predict the fate of E1 and E2 in batch tests using the sludge from the BNR process was calibrated using the data from the experiments. The biotransformation rate constants for the transformation of E2 to E1 were estimated as 71 ± 1.5, 31 ± 3.3 and 1 ± 0.9 L g COD−1 d−1 for the aerobic, anoxic and anaerobic batch tests, respectively, while the corresponding biotransformation rate constants for the transformation of E1 were estimated to be 7.3 ± 1.0, 3 ± 2.0, and 0.85 ± 0.6 L·g COD−1 d−1. A steady state mass balance model formulated to describe the interactions between E2 and E1 in BNR activated sludge reasonably described the fate of E1 and E2 in the BNR process. - Highlights: • Comparable estrogenicity removal was observed from two BNR processes. • Pseudo first order model described the transformation of E2 and E1 in BNR process. • Biotransformation of E1 in BNR activated sludge controls the degradation of E2

  2. Assessment of the removal of estrogenicity in biological nutrient removal wastewater treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    Ogunlaja, O.O., E-mail: oogunlaj@uwaterloo.ca; Parker, W.J., E-mail: wjparker@uwaterloo.ca

    2015-05-01

    The removal of estrogenicity in a University of Cape Town-biological nutrient removal (UCT-BNR) wastewater treatment process was investigated using pilot and bench scale systems, batch experiments and mathematical modeling. In the pilot BNR process, 96 ± 5% of the estrogenicity exerted by the influent wastewater was removed by the treatment process. The degradation efficiencies in the anaerobic, anoxic and aerobic zones of the pilot BNR bioreactor were 11 ± 9%, 18 ± 2% and 93 ± 10%, respectively. In order to further understand the performance of the BNR process in the removal of estrogenicity from wastewater, a bench scale BNR process was operated with synthetic wastewater dosed with E1 and E2. The removal of estrogenicity in the bench scale system (95 ± 5%) was comparable to the pilot BNR process and the degradation efficiencies were estimated to be 8 ± 0.8%, 38 ± 4% and 85 ± 22% in the anaerobic, anoxic and aerobic zones, respectively. A biotransformation model developed to predict the fate of E1 and E2 in batch tests using the sludge from the BNR process was calibrated using the data from the experiments. The biotransformation rate constants for the transformation of E2 to E1 were estimated as 71 ± 1.5, 31 ± 3.3 and 1 ± 0.9 L g COD{sup −1} d{sup −1} for the aerobic, anoxic and anaerobic batch tests, respectively, while the corresponding biotransformation rate constants for the transformation of E1 were estimated to be 7.3 ± 1.0, 3 ± 2.0, and 0.85 ± 0.6 L·g COD{sup −1} d{sup −1}. A steady state mass balance model formulated to describe the interactions between E2 and E1 in BNR activated sludge reasonably described the fate of E1 and E2 in the BNR process. - Highlights: • Comparable estrogenicity removal was observed from two BNR processes. • Pseudo first order model described the transformation of E2 and E1 in BNR process. • Biotransformation of E1 in BNR activated sludge controls the degradation of E2.

  3. Removal of nitrogen and phosphorus in a combined A2/O-BAF system with a short aerobic SRT

    Institute of Scientific and Technical Information of China (English)

    DING Yong-wei; WANG Lin; WANG Bao-zhen; WANG Zheng

    2006-01-01

    A bench-scale anaerobic/anoxic/aerobic process-biological aerated filter (A2/O-BAF) combined system was carried out to treat wastewater with lower C/N and C/P ratios. The A2/O process was operated in a short aerobic sludge retention time (SRT) for organic pollutants and phosphorus removal, and denitrification. The subsequent BAF process was mainly used for nitrification. The BAF effluent was partially returned to anoxic zone of the A2/O process to provide electron acceptors for denitrification and anoxic P uptake. This unique system formed an environment for reproducing the denitrifying phosphate-accumulating organisms (DPAOs). The ratio of DPAOs to phosphorus accumulating organisms (PAOs) could be maintained at 28% by optimizing the organic loads in the anaerobic zone and the nitrate loads into the anoxic zone in the A2/O process. The aerobic phosphorus over-uptake and discharge of excess activated sludge was the main mechanism of phosphorus removal in the combined system. The aerobic SRT of the A2/O process should meet the demands for the development of aerobic PAOs and the restraint on the nitrifiers growth, and the contact time in the aerobic zone of the A2/O process should be longer than 30 min, which ensured efficient phosphorus removal in the combined system. The adequate BAF effluent retum rates should be controlled with 1-4 mg/L nitrate nitrogen in the anoxic zone effluent of A2/O process to achieve the optimal nitrogen and phosphorus removal efficiencies.

  4. A novel approach to enhance biological nutrient removal using a culture supernatant from Micrococcus luteus containing resuscitation-promoting factor (Rpf) in SBR process.

    Science.gov (United States)

    Liu, Yindong; Su, Xiaomei; Lu, Lian; Ding, Linxian; Shen, Chaofeng

    2016-03-01

    A culture supernatant from Micrococcus luteus containing resuscitation-promoting factor (SRpf) was used to enhance the biological nutrient removal of potentially functional bacteria. The obtained results suggest that SRpf accelerated the start-up process and significantly enhanced the biological nutrient removal in sequencing batch reactor (SBR). PO4 (3-)-P removal efficiency increased by over 12 % and total nitrogen removal efficiency increased by over 8 % in treatment reactor acclimated by SRpf compared with those without SRpf addition. The Illumina high-throughput sequencing analysis showed that SRpf played an essential role in shifts in the composition and diversity of bacterial community. The phyla of Proteobacteria and Actinobacteria, which were closely related to biological nutrient removal, were greatly abundant after SRpf addition. This study demonstrates that SRpf acclimation or addition might hold great potential as an efficient and cost-effective alternative for wastewater treatment plants (WWTPs) to meet more stringent operation conditions and legislations. PMID:26514565

  5. Comprehensive analysis of soil nitrogen removal by catch crops based on growth and water use

    Science.gov (United States)

    Yasutake, D.; Kondo, K.; Yamane, S.; Kitano, M.; Mori, M.; Fujiwara, T.

    2016-07-01

    A new methodology for comprehensive analysis of the characteristics of nitrogen (N) removal from greenhouse soil by catch crop was proposed in relation to its growth and water use. The N removal is expressed as the product of five parameters: net assimilation rate, specific leaf area, shoot dry weight, water use efficiency for N removal, and water requirement for growth. This methodology was applied to the data of a greenhouse experiment where corn was cultivated under three plant densities. We analyzed the effect of plant density and examined the effectiveness of the methodology. Higher plant densities are advantageous not only for total N removal but also for water use efficiency in N removal and growth because of the large specific leaf area, shoot dry weight, and decreased soil evaporation. On the other hand, significant positive or negative linear relationships were found between all five parameters and N removal. This should improve the understanding of the N removal mechanisms and the interactions among its components. We show the effectiveness of our analytical methodology, which can contribute to identifying the optimum plant density according to the field situations (available water amount, soil N quantity to be removed) for practical catch crop cultivation.

  6. Comparing results of cultured and uncultured biological methods used in biological phosphorus removal

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Increasing attention has been paid to phosphate-accumulating organisms (PAOs) for their important role in biological phosphorus removal. In this study, microbial communities of PAOs cultivated under different carbon sources (sewage, glucose, and sodium acetate) were investigated and compared through culture-dependent and culture-independent methods, respectively. The results obtained using denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction-amplified 16S rDNA fragments revealed that the diversity of bacteria in a sewage-fed reactor (1#) was much higher than in a glucose-fed one (2#) and a sodium acetate-fed one (3#); there were common PAOs in three reactors fed by different carbon sources. Five strains were separated from three systems by using a phosphate-rich medium; they were from common bacteria isolated and three isolates could not be found in DGGE profile at all. Two isolates had good phosphorus removal ability. When the microbial diversity was studied, the molecular biological method was better than the culture-dependent one. When phosphorus removal characteristics were investigated, culture-dependent approach was more effective. Thus a combination of two methods is necessary to have a comprehensive view of PAOs.

  7. Assessment of biomass functionalities in a biofilm membrane bioreactor (BF-MBR) targeting biological nutrient removal

    OpenAIRE

    Kjørlaug, Oda Marie

    2013-01-01

    High concentrations of nutrients such as nitrogen, phosphorus and organicmatter can cause serious eutrophication in receiving water bodies. In biologicalwastewater treatment microorganisms remove nutrients from thewastewater and ensure that these components in the final effluent stay atacceptable levels.A biofilm membrane bioreactor (BF-MBR) removing nitrogen, phosphorusand carbon from municipal wastewater was operated for 85 days. Anassessment of the process focusing on the biomass in the va...

  8. Efficiency promotion and its mechanisms of simultaneous nitrogen and phosphorus removal in stormwater biofilters.

    Science.gov (United States)

    Zhou, Zijun; Xu, Peng; Cao, Xiuyun; Zhou, Yiyong; Song, Chunlei

    2016-10-01

    Stromwater biofilter technology was greatly improved through adding iron-rich soil, plant detritus and eutrophic lake sediment. Significant ammonium and phosphate removal efficiencies (over 95%) in treatments with iron-rich soil were attributed to strong adsorption capability resulting in high available phosphorus (P) in media, supporting the abundance and activity of nitrifiers and denitrifiers as well as shaping compositions, which facilitated nitrogen (N) removal. Aquatic and terrestrial plant detritus was more beneficial to nitrification and denitrification by stimulating the abundance and activity of nitrifiers and denitrifiers respectively, which increased total nitrogen (TN) removal efficiencies by 17.6% and 22.5%. In addition, bioaugmentation of nitrifiers and denitrifiers from eutrophic sediment was helpful to nutrient removal. Above all, combined application of these materials could reach simultaneously maximum effects (removal efficiencies of P, ammonium and TN were 97-99%, 95-97% and 60-63% respectively), suggesting reasonable selection of materials has important contribution and application prospect in stormwater biofilters. PMID:27428301

  9. Nitrogen removal kinetics in the treatment of landfill leachate by SBR systems

    International Nuclear Information System (INIS)

    In this study, laboratory-scale experiments were conducted applying the SBR activated sludge process to leachate from an old MSW landfill operating for 7 years. Due to the fact that old leachate is characterized with a high concentration of ammonia (approximately 1500 mgN/1) and low availability of readily biodegradable organic matter (BOD5/COD,06), the aim was to examine the nitrogen removal process and to compare the efficiency of one-stage and two stage systems operating at temperature of 20 C and 12 C. The second alternative SBR configuration is based on the coupling of two SBR reactors: the first one specialized in nitrification and the second one in post-denitrification, with external carbon source addition. By the efficient removal of nitrogen, an on-site pretreatment of leachate allows to comply with the limits required for discharging into sewers or into municipal wastewater treatment plant

  10. The Spatial Distribution of Nitrogen Removal Functional Genes in Multimedia Constructed Wetlands for Wastewater Treatment.

    Science.gov (United States)

    Ji, Guodong; He, Chunguang; Tan, Yufei; Yang, Zhonghua

    2015-11-01

    The real-time polymerase chain reaction was used to quantitatively evaluate distribution patterns and nitrogen removal pathways of the amoA, nxrA, narG, napA, nirK, qnorB, nosZ, nas, and nifH genes and 16S rRNA in anaerobic ammonia oxidation bacteria in four multimedia constructed wetlands for rural wastewater treatment. The results indicated that the abundance of functional genes for nitrogen removal in the rhizosphere layer (0 to 30 cm), water distribution layer (30 to 50 cm), multime filler layer (50 to 130 cm), and catchment layer (130 to 170 cm) of the constructed wetlands were closely related. The rhizosphere layer was conducive to the absolute enrichment of dominant genes. The other three layers were favorable to the relative enrichment of rare genes. PMID:26564582

  11. A novel control strategy for single-stage autotrophic nitrogen removal in SBR

    DEFF Research Database (Denmark)

    Mauricio Iglesias, Miguel; Vangsgaard, Anna Katrine; Gernaey, Krist; Smets, Barth F.; Sin, Gürkan

    2015-01-01

    A novel feedforward–feedback control strategy was developed for complete autotrophic nitrogen removal in a sequencing batch reactor. The aim of the control system was to carry out the regulation of the process while keeping the system close to the optimal operation. The controller was designed...... based on a process model and then tested experimentally. The resulting batch-to-batch control strategy had the total nitrogen removal efficiency as controlled variable and the setting of the aeration mass flow controller as manipulated variable. Compared to manual operation mode (constant air supply...... lab-scale reactor is a promising result, which brings this control strategy one step closer to full-scale implementation....

  12. Biological nitrogen fixation by lucerne (Medicago sativa L.) in acid soils.

    NARCIS (Netherlands)

    Pijnenborg, J.W.M.

    1990-01-01

    Growth of lucerne( Medicago sativa L.) is poor in soils with values of pH-H2O below 6. This is often due to nitrogen deficiency, resulting from a hampered performance of the symbiosis withRhizobium meliloti. This thesis deals with the factors affecting biological nitrogen fixat

  13. Robust biological nitrogen fixation in a model grass-bacterial association.

    Science.gov (United States)

    Pankievicz, Vânia C S; do Amaral, Fernanda P; Santos, Karina F D N; Agtuca, Beverly; Xu, Youwen; Schueller, Michael J; Arisi, Ana Carolina M; Steffens, Maria B R; de Souza, Emanuel M; Pedrosa, Fábio O; Stacey, Gary; Ferrieri, Richard A

    2015-03-01

    Nitrogen-fixing rhizobacteria can promote plant growth; however, it is controversial whether biological nitrogen fixation (BNF) from associative interaction contributes to growth promotion. The roots of Setaria viridis, a model C4 grass, were effectively colonized by bacterial inoculants resulting in a significant enhancement of growth. Nitrogen-13 tracer studies provided direct evidence for tracer uptake by the host plant and incorporation into protein. Indeed, plants showed robust growth under nitrogen-limiting conditions when inoculated with an ammonium-excreting strain of Azospirillum brasilense. (11)C-labeling experiments showed that patterns in central carbon metabolism and resource allocation exhibited by nitrogen-starved plants were largely reversed by bacterial inoculation, such that they resembled plants grown under nitrogen-sufficient conditions. Adoption of S. viridis as a model should promote research into the mechanisms of associative nitrogen fixation with the ultimate goal of greater adoption of BNF for sustainable crop production. PMID:25645593

  14. Computation of Bond Dissociation Energies for Removal of Nitrogen Dioxide Groups in Certain Aliphatic Nitro Compounds

    Institute of Scientific and Technical Information of China (English)

    SHAO Ju-Xiang; CHENG Xin-Lu; YANG Xiang-Dong; XIANG Shi-Kai

    2006-01-01

    @@ Bond dissociation energies for removal of nitrogen dioxide groups in 10 aliphatic nitro compounds, including nitromethane, nitroethylene, nitroethane, dinitromethane, 1-nitropropane, 2-nitropropane, 1-nitrobutane,2-methyl-2-nitropropane, nitropentane, and nitrohexane, are calculated using the highly accurate complete basis set (CBS-Q) and the three hybrid density functional theory (DFT) methods B3LYP, B3PW91 and B3P86 with 6-31G** basis set.

  15. Immobilized periphytic cyanobacteria for removal of nitrogenous compounds and phosphorus from shrimp farm wastewater

    OpenAIRE

    Banerjee, Sanjoy; Khatoon, Helena; Shariff, Mohamed; YUSOFF, FATIMAH

    2015-01-01

    Cyanobacteria can be used to remove nitrogenous compounds from wastewater, but a major bottleneck in the process is the separation of cyanobacterial biomass from the treated water discharge, which may cause eutrophication. The current study assessed the suitability of three periphytic cyanobacteria (Geitlerinema sp., Gloeotrichia sp., and Lyngbya sp.) isolated from shrimp ponds. These cyanobacteria were immobilized by self-adhesion to polyvinyl chloride sheets, forming mats, and were screened...

  16. Effect of Algal Biofilm and Operational Conditions on Nitrogen Removal in Wastewater Stabilization Ponds

    OpenAIRE

    Babu, M.

    2011-01-01

    Discharge of nutrient rich wastewater causes eutrophication of surface water; therefore wastewater treatment before discharge is required. Wastewater stabilization ponds are low cost technology used by developing countries but not effective in nitrogen removal due to low nitrifier biomass in the water column. Introduction of surface area for attachment of nitrifiers has therefore been proposed. This thesis reports the performance of pilot scale wastewater stabilization ponds fitted with baffl...

  17. Electroflotation clarifier to enhance nitrogen removal in a two-stage alternating aeration bioreactor.

    Science.gov (United States)

    Cho, Kangwoo; Chung, Chong Min; Kim, Yun Jung; Hoffmann, Michael R; Chung, Tai Hak

    2013-01-01

    Stringent water treatment criteria and rapidly growing pollutant loads provoke the demand for retrofitting wastewater treatment plants towards a higher capacity. In this study, we assess a two stage alternating aeration (AA) bioreactor equipped with electroflotation (EF) clarifier, for nitrogen removal within a short hydraulic retention time (HRT). The EF under steady solids loading required a minimum unit height and gas: solids ratio of 0.006 for efficient clarification. The separated sludge blanket was further thickened with retaining stability when the cyclic solids loading was smaller than 1.0 kg m(-2). In the continuous operation of the bioreactor, the returned activated sludge concentration increased to more than 18,000 mg L(-1), while the effluent suspended solids concentration was lowered below 5 mg L(-1). Under influent chemical oxygen demand (COD)/total inorganic nitrogen (TIN) concentration of 300/30 mg L(-1), the TIN removal efficiency was near 70% with cycle time ratios of 0.17 and 0.27. Under higher influent COD concentration of 500mg L(-1), TIN removal efficiency was found to be 73.4% at a carbon:nitrogen (C:N) ratio of 10 and even higher (80.4%) at a C:N ratio of 16.6. The increased mixed liquor suspended solids concentrations (> 6000 mg L(-1)) under the high COD loading were efficiently maintained by using the EF clarifier. The results of this study demonstrate that an EF clarifier with a HRT of less than 1 h can support reliable nitrogen removal in the AA process that has a HRT of 6 h, even under increasing influent loadings. PMID:24527640

  18. Observation of Nitrogen and Phosphorus Removals and Accumulations in Surface Flow Constructed Wetland (SFCW)

    OpenAIRE

    Suntud Sirianuntapiboon; Prapa Sohsalam

    2012-01-01

    The tropical emergent plant species; Cyperus involucratus, Canna siamensis, Heliconia sp., Hymenocallis littoralis, Typha augustifolia and Thalia dealbata were used to observe nutrients (total phosphorus: TP and total nitrogen: TN) removal efficiencies of surface flow constructed wetland (SFCW). The system was operated at different hydraulic retention time (HRT) of 1, 3 and 5 days and the average atmospheric temperature of 29.1 ± 4.9oC. The seafood industrial wastewater was employed as the in...

  19. A possible method for in situ nitrogen removal in landfills by microbial-pumping-iron behavior.

    Science.gov (United States)

    Long, Yuyang; Xu, Jing; Du, Yao; Feng, Huan; Fang, Yuan; Shen, Dongsheng

    2016-06-15

    Nitrogen pollution from landfills needs urgent treatment. A batch experiment was designed to explore the possible in situ nitrogen removal in landfills based on the hypothesis of microbial-pumping-iron behavior, namely anaerobic microbial iron oxidation and reduction. The results confirm that a simultaneous Fe(ii) oxidation, accompanied by nitrate (NO3(-)-N) reduction and dissimilatory Fe(iii) reduction, can happen in aged municipal solid waste (AMSW). This phenomenon can last at least 10 years after landfilling. Organics is an important intermediate medium in that process. The dynamic anaerobic Fe redox cycle has the potential of denitrification without ammonia nitrogen (NH4(+)-N) accumulation. AMSW with deposited ages of 1-3 years is a good choice to enhance this redox cycle behavior coupled with denitrification. Conversely, AMSW with longer deposited ages (8-10 years) has a quicker iron cycle and a smaller NH4(+)-N accumulation. This suggests a possible method for in situ nitrogen removal in landfills. PMID:27194007

  20. Ammonia-based intermittent aeration control optimized for efficient nitrogen removal.

    Science.gov (United States)

    Regmi, Pusker; Bunce, Ryder; Miller, Mark W; Park, Hongkeun; Chandran, Kartik; Wett, Bernhard; Murthy, Sudhir; Bott, Charles B

    2015-10-01

    This work describes the development of an intermittently aerated pilot-scale process (V = 0.45 m(3) ) operated for optimized efficient nitrogen removal in terms of volume, supplemental carbon and alkalinity requirements. The intermittent aeration pattern was controlled using a strategy based on effluent ammonia concentration set-points. The unique feature of the ammonia-based aeration control was that a fixed dissolved oxygen (DO) set-point was used and the length of the aerobic and anoxic time (anoxic time ≥25% of total cycle time) were changed based on the effluent ammonia concentration. Unlike continuously aerated ammonia-based aeration control strategies, this approach offered control over the aerobic solids retention time (SRT) to deal with fluctuating ammonia loading without solely relying on changes to the total SRT. This approach allowed the system to be operated at a total SRT with a small safety factor. The benefits of operating at an aggressive SRT were reduced hydraulic retention time (HRT) for nitrogen removal. As a result of such an operation, nitrite oxidizing bacteria (NOB) out-selection was also obtained (ammonia oxidizing bacteria [AOB] maximum activity: 400 ± 79 mgN/L/d, NOB maximum activity: 257 ± 133 mgN/L/d, P < 0.001) expanding opportunities for short-cut nitrogen removal. The pilot demonstrated a total inorganic nitrogen (TIN) removal rate of 95 ± 30 mgN/L/d at an influent chemical oxygen demand: ammonia (COD/NH4 (+) -N) ratio of 10.2 ± 2.2 at 25°C within the hydraulic retention time (HRT) of 4 h and within a total SRT of 5-10 days. The TIN removal efficiency up to 91% was observed during the study, while effluent TIN was 9.6 ± 4.4 mgN/L. Therefore, this pilot-scale study demonstrates that application of the proposed on-line aeration control is capable of relatively high nitrogen removal without supplemental carbon and alkalinity addition at a low HRT. PMID:26058705

  1. Improving food and agricultural production. Thailand. Biological nitrogen fixation

    International Nuclear Information System (INIS)

    The aim of the mission was to assist the counterpart scientists in the analysis and interpretation of data relating to nitrogen fixation studies on grain legumes. The report briefly summarizes the discussions that were held with the counterparts

  2. Biogas-utilizing nitrogen removal with a semi-partitioned reactor

    Energy Technology Data Exchange (ETDEWEB)

    Waki, M.; Suzuki, K.; Tanaka, Y. [National Inst. of Livestock and Grassland Science, Tsukuba, Ibaraki (Japan). Dept. of Livestock Industry Environment; Osada, T. [National Agricultural Research Center for Hokkaido Region, Sapporo, Hokkaido (Japan). Research Team for Harmony with Environment; Ike, M.; Fujita, M. [Osaka Univ., Osaka (Japan). Dept. of Environmental Engineering

    2004-07-01

    This paper presents a newly developed reactor to remove nitrogen using methane. This pilot study examined the feasibility of using such a reactor with swine wastewater. Denitrification of methane requires methane (CH{sub 4}) and oxygen (O{sub 2}). The problem is that the reactor off-gases contains both these gases in mixture, therefore, they are not usable as energy sources. A semi-partitioned reactor (SPR) was designed to discharge off-gases containing a high-concentration methane that can be used as energy. The partitioned headspace in the SPR extended partly into the liquid layer. The methane and oxygen were supplied separately to the liquid layer on the other side of the partition. The in flowing fluid was swine wastewater, the methane source was the biogas produced in the reactor and air was the oxygen source. During the 6 month pilot study, nitrogen was removed at an average rate of 0.11 kg N/m{sup 3} of wastewater. The methane concentration in off-gas was high enough to generate electricity. Adsorption removed hydrogen sulfide from the biogas. Nitrogen oxides were contained in off-gas from the reactor. 5 refs., 6 figs.

  3. Nitrous oxide production during nitrogen removal from domestic wastewater in lab-scale sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    LIU Xiuhong; PENG Yi; WU Changyong; AKIO Takigawa; PENG Yongzhen

    2008-01-01

    The production of N2O during nitrogen removal from real domestic wastewater was investigated in a lab-scale aerobic-anoxic sequencing batch reactor with a working volume of 14 L.The results showed that the total N2O-N production reached higher than 1.87 mg/L,and up to 4% of removed nitrogen was converted into N2O.In addition,N2O led to a much higher greenhouse effect than CO2 during aerobic reaction phase,this proved that N2O production could not be neglected.The N2O-N production during nitrification Was 1.85 mg/L,whereas,during denitrification,no N2O was produced,nitrification was the main source of N2O production during nitrogen removal.Furthermore,during denitrification,the dissolved N2O at the end of aeration Was found to be further reduced to N2.Denitrification thus had the potential of controlling N2O production.

  4. Struvite Precipitation for Ammonia Nitrogen Removal in 7-Aminocephalosporanic Acid Wastewater

    OpenAIRE

    Erhong Duan; Jingliang Yang; Ping Chen; Yanfang Liu; Jiane Zuo; Zaixing Li; Xuguang Ren; Yongjun Wang

    2012-01-01

    7-Aminocephalosporanic acid wastewater usually contains high concentrations of ammonium (NH4+-N), which is known to inhibit nitrification during biological treatment processes. Chemical precipitation is a useful technology to remove ammonium from wastewater. In this paper, the removal of ammonium from 7-aminocephalosporanic acid wastewater was studied. The optimum pH, molar ratio, and various chemical compositions of magnesium ammonium phosphate (MAP) precipitation were investigated. The resu...

  5. Experimental study on the removal of ammonia nitrogen and total nitrogen with algae from coal-gasification wastewater%藻类去除煤气化废水氨氮及总氮的实验研究

    Institute of Scientific and Technical Information of China (English)

    刘肃力; 纪钦洪; 于广欣; 卿人韦

    2013-01-01

    The column photo-bioreactor has been used for algae removing ammonia nitrogen and total nitrogen with algae from coal-gasification wastewater.Experimental results show that under the optimized conditions,Scenedesmus quadricanda,Scnedesmus obliquus and compound algae (Tribonema and Phormidium) can make statistically thorough removal of the ammonia nitrogen from coal-gasification wastewater within 3 d,and the removing efficiency of total nitrogen from coal-gasification wastewater has reached the maximum on the 5th day,which is 86.02% with Scenedesmus quadricanda,83.33% with Senedesmus obliquus,and 71.81% with the compound algae.The results reveal that it is feasible to remove ammonia nitrogen and total nitrogen from coal gasification wastewater by using appropriate algae.Besides,compared with the biological nitrification/denitrification denitrogenation process,the process is also significantly original.%采用柱式光合反应器对藻类去除煤气化废水的氨氮及总氮开展了探索性实验研究.实验结果表明:优化条件下,四尾栅藻、斜生栅藻、混合藻(黄丝藻和席藻)都在3d内完全去除氨氮,同时总氮去除率都在第5天达到最大,分别是四尾栅藻86.02%,斜生栅藻83.33%,混合藻71.81%.说明选用合适的藻类去除煤气化废水的氨氮及总氮可行,同时相比生物硝化/反硝化脱氮工艺该方法具有一定的新颖性.

  6. Biological nitrate removal from wastewater of a metal-finishing industry

    International Nuclear Information System (INIS)

    An upflow packed bed reactor at laboratory scale has been operated for a continuous period of 5 months to investigate the technical feasibility of biological nitrate removal applied to the effluent of the coagulation-sedimentation wastewater of a metal-finishing industry. The reactor was fed with industrial wastewater in a five-fold dilution to reproduce the global spill in the factory (20/80, industrial wastewater/domestic wastewater) with a concentration of nitrate between 141 and 210 g NO3-N/m3. Methanol was added as a carbon source for denitrification. Inlet flow rate was progressively increased from 9 to 40 L/day (nitrogen input load from 45 to 250 g NO3-N/(m3 h)). The highest observed denitrification rate was 135 g NO3-N/(m3 h) at a nitrate load of 250 g NO3-N/(m3 h), and removal efficiencies higher than 90% were obtained for loads up to 100 g NO3-N/(m3 h). A mass relation between COD consumed and NO3-N removed around 3.31 was observed. Better results were achieved in a previous stage using tap water with nitrate added as a sole pollutant as a synthetic feed (critical load of 130 g NO3-N/(m3 h) and denitrification rate of 200 g NO3-N/(m3 h) at a nitrate load of 250 g NO3-N/(m3 h)). This fact could indicate that the chemical composition of the industrial source hinders to some extent the performance of the biological process. Whatever case, results demonstrated the viability of the denitrification process for the global industrial wastewater. A simple model based on Monod kinetics for substrate consumption, and constant biomass concentration was applied to model the industrial wastewater treatment, and a reasonably good fitting was obtained

  7. Selective adsorption for removal of nitrogen compounds from hydrocarbon streams over carbon-based adsorbents

    Science.gov (United States)

    Almarri, Masoud S.

    desulfurization of model diesel fuel, which contains equimolar concentrations of nitrogen (i.e., quinoline and indole), sulfur (i.e., dibenzothiophene and 4,6-dimethyldibenzothiophene), and aromatic compounds (naphthalene, 1-methylnaphthalene, and fluorene), was examined. The results revealed that when both nitrogen and sulfur compounds coexist in the fuel, the type and density of oxygen functional groups on the surface of the activated carbon are crucial for selective adsorption of nitrogen compounds but have negligible positive effects for sulfur removal. The adsorption of quinoline and indole is largely governed by specific interactions. There is enough evidence to support the importance of dipole--dipole and acid-base-specific interactions for the adsorption of both quinoline and indole. Modified carbon is a promising material for the efficient removal of the nitrogen compounds from light cycle oil (LCO). Adsorptive denitrogenation of LCO significantly improved the hydrodesulfurization (HDS) performance, especially for the removal of the refractory sulfur compounds such as 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene. An essential factor in applying activated carbon for adsorptive denitrogenation and desulfurization of liquid hydrocarbon streams is regeneration after saturation. The regeneration method of the saturated adsorbents consisted of toluene washing followed by heating to remove the remaining toluene. The results show that the spent activated carbon can be regenerated to completely recover the adsorption capacity. The high capacity and selectivity of activated carbon for nitrogen compounds, along with their ability to be regenerated, indicate that activated carbon is a promising adsorbent for the deep denitrogenation of liquid hydrocarbon streams.

  8. [Removal nitrogen of integrated vertical-flow constructed wetland under aeration condition].

    Science.gov (United States)

    Tao, Min; He, Feng; Xu, Dong; Zhou, Qiao-Hong; Liang, Wei; Chen, Shui-Ping; Wu, Zhen-Bin

    2011-03-01

    Oxygen is an important limit factor of nitrogen removal in constructed wetlands, so it is the key point for improving nitrogen removal efficiency of constructed wetlands that the optimization of oxygen distribution within wetlands. Therefore, oxygen status, nitrogen removal and purification mechanism of integrated vertical-flow constructed wetland (IVCW) under aeration condition in summer and winter have been studied. The results showed that both oxygen levels and aerobic zones were increased in the wetland substrates. The area of oxic zone I (expressing with depth) extended from 22 cm, 17 cm to 53 cm, 44 cm, in summer and winter, respectively. The electric potential (Eh) profiling demonstrated that artificial aeration maintained the pattern of sequential oxic-anoxic-oxic (O-A-O) redox zones within the aerated IVCW in winter, while only two oxic-anoxic (O-A) zones were present inside the non-aerated IVCW in the cold season. The decomposition of organic matter and nitrification were obviously enhanced by artificial aeration since the removal efficiency of COD, TN and NH4(+) -N were increased by 12.2%, 6.9% and 15.1% in winter, respectively. There was no significant accumulation of NO3(-) -N in the effluent with an aeration cycle of 8 h on and 16 h off in this experiment. Moreover, we found that oxic zone I was the main region of pollutants removal in IVCW system, and artificial aeration mainly acted to enhance the purification capacity of this oxic zone in the aerated IVCW. These results suggest that aeration is important for optimization and application of IVCW system. PMID:21634169

  9. Nitrogen removal from recycled landfill leachate by ex situ nitrification and in situ denitrification

    International Nuclear Information System (INIS)

    A three-compartment system, comprising a landfill column with fresh municipal solid waste, a column with a well-decomposed refuse layer as methane producer, and a sequential batch reactor as ex situ nitrifying reactor, was employed to remove nitrogen from municipal solid waste leachate. Since food waste comprised a major portion of refuse collected in Shanghai, an intense hydrolysis reaction occurred and caused the rapid accumulation of ammonia nitrogen (NH3-N) and total organic carbon in the leachate. This paper discusses the role of the three mentioned units and the design and operation of the proposed system. With most NH3-N being converted to nitrite nitrogen (NO2--N) or nitrate nitrogen (NO3--N) by the nitrifying reactor, and with the well-decomposed refuse layer transforming most dissolved organic compounds to CO2, carbonates and methane, it was found that the fresh refuse column could efficiently denitrify the hydrolyzed nitrogen to N2 gas. The role of the three mentioned units and comments on the design and operation of the proposed system are also discussed

  10. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    International Nuclear Information System (INIS)

    Highlights: ► We analyzed biological effects of N+ implantation on dry Jatropha curcas seed. ► N+ implantation greatly decreased seedling survival rate. ► At doses beyond 15 × 1016 ion cm−2, biological repair took place. ► CAT was essential for H2O2 removal. POD mainly functioned as seed was severely hurt. ► HAsA–GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N+ with energy of 25 keV was applied to treat the dry seed at six different doses. N+ beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 1016 to 15 × 1016 ions cm−2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 1016 ion cm−2, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 1016 ions cm−2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA–GSH cycle appeared to be for regeneration of HAsA.

  11. Performance evaluation of a novel anaerobic-anoxic sludge blanket reactor for biological nutrient removal treating municipal wastewater.

    Science.gov (United States)

    Díez-Montero, Rubén; De Florio, Loredana; González-Viar, Marta; Herrero, María; Tejero, Iñaki

    2016-06-01

    A novel anaerobic-anoxic sludge blanket reactor, AnoxAn, unifies the non-aerated zones of the biological nutrient removal treatment train in a single upflow reactor, aimed at achieving high compactness and efficiency. The environmental conditions are vertically divided up inside the reactor with the anaerobic zone at the bottom and the anoxic zone above. This contribution presents the performance evaluation of the novel reactor in the removal of organic matter and nutrients from municipal wastewater, coupled with an aerobic hybrid MBR. The overall system achieved total nitrogen and phosphorus removal with average efficiencies of 75% and 89%, respectively. Separate anoxic and anaerobic conditions were maintained in AnoxAn, allowing anaerobic phosphate release and nearly complete anoxic denitrification in the single reactor operating with an HRT of 4.2h. Biomass was retained in the reactor achieving TSS concentration up to 10gL(-1) and partial hydrolysis of influent particulate organic matter. PMID:26970922

  12. Nitrogen removal for low-carbon wastewater in reversed A~2/O process by regulation technology

    Institute of Scientific and Technical Information of China (English)

    张智; 陈杰云; 谢丽华; 范功端; 尹晓静; 李勇

    2009-01-01

    Full scale experimental study on nitrogen removal for low-carbon wastewater was conducted in reversed A2/O process in Jiguanshi waste water treatment plant in Chongqing,in order to aid the operation and maintenance of similar WWTP. When the proposed measures,such as using 0.1% (volume fraction of wastewater) landfill leachate,shortening HRT by 2/3 in the primary sedimentation tank and controlling DO at 0.5 mg/L in the 3rd section of aerobic zone,are applied,15% of the carbon source can be complemented,the favorable property of activated sludge is achieved,and the nitrogen removal effect is significantly improved. The effluent NH3-N is 2 mg/L and the removal rate is 90%. The effluent TN is 17 mg/L and the removal rate is 54%. The up-to-standard discharge of the effluent is achieved. And after the optimization,the unit electricity consumption also reaches 0.21 kW/h and saves 20%.

  13. Simultaneous Nitrogen and Phosphorus Removal by Denitrifying Dephosphatation in a (AO)2 Sequencing Batch Reactor

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan-ping; PENG Yong-zhen; WANG Shu-ying; WANG Shao-po

    2005-01-01

    A 24 L working volume reactor was used for the research on simultaneous phosphorus (P) and nitrogen (N) removal by denitrifying dephosphatation in an anaerobic-oxid-anoxic-oxid sequencing batch reactor ((AO)2SBR) system. The durations of each phase are: anaerobic 1.5 h, aerobic 2.5 h, anoxic 1.5 h, post-aerobic 0.5 h, settling 1.0 h, fill 0.5 h. The successful removal of nitrogen and phosphorus is achieved in a stable (AO)2SBR. The effluent P concentrations is below 1 mg/L, and the COD,TN and P average removal efficiency is 88.9%, 77.5% and 88.7%, respectively. The batch experiment results show that the durations of aerobic and anoxic phase influence the P removal efficiency. Some feature points are found on the DO, ORP and pH curves to demonstrate the complete of phosphate release and phosphate uptake. These feature points can be used for the control of (AO)2 SBR.

  14. High-rate nitrogen removal by the Anammox process with a sufficient inorganic carbon source.

    Science.gov (United States)

    Yang, Jiachun; Zhang, Li; Fukuzaki, Yasuhiro; Hira, Daisuke; Furukawa, Kenji

    2010-12-01

    This study focused on high-rate nitrogen removal by the anaerobic ammonium oxidation (Anammox) process with a sufficient inorganic carbon (IC) source. Experiments were carried out in an up-flow column Anammox reactor fed with synthetic inorganic wastewater for 110 days. The IC source was added into the influent tank in the form of bicarbonate. The results confirmed the positive impact of inorganic matter on stimulating Anammox activity. After the addition of sufficient IC, the nitrogen removal rate sharply increased from 5.2 to 11.8 kg-Nm(-3)day(-1) within only 32 days. NO(2)-N inhibition was not observed even at NO(2)-N concentrations greater than 460 mgN/L, indicating the enriched Anammox consortium adapted to high NO(2)-N concentrations. The ratio of NO(2)-N removal, NO(3)-N production and NH(4)-N removal for the reactor was correspondingly changed from 1.21:0.21:1 to 1.24:0.18:1. Simultaneously, the sludge volume index of the Anammox granules decreased markedly from 36.8 to 21.5 mL/g, which was attributed to the implementation of proper operational strategy. In addition, DNA analysis revealed that a shift from the KSU-1 strain to the KU2 strain occurred in the Anammox community. PMID:20709538

  15. Removal of nitrogen and phosphorus from dairy wastewater using constructed wetlands systems operating in batch

    Directory of Open Access Journals (Sweden)

    Ronaldo Rocha Bastos

    2012-08-01

    Full Text Available This work presents the results of a study conducted for a period of seven months on the effectiveness of constructed wetland systems for the treatment of dairy wastewater aiming at removing, nitrogen and phosphorus. Six experimental systems were assembled with a net volume of 115 L using HDPE tanks, with length/width ratio of 2:1. In three of the systems, gravel 0 was used as substrate, while gravel 0 and sand was used in the three others, in the percentage of 80% and 20%, respectively. The systems were operated in batch cycles of 48 hours, applying 7.5 L of influent per cycle. Four of the experimental units were cultivated, and two kept as controls. The selected species chosen were the macrophytes, Typha domingensis and Hedychium coronarium. The removal efficiency concerning nitrogen compounds showed to be quite promising with values ranging from 29.4 to 73.4%, while phosphorus removal from the beds was lower, reaching efficiencies between 18.61 and 34.3%, considered good values, since the removal of these substances is quite difficult through conventional treatment.

  16. Reactor performance in terms of COD and nitrogen removal and bacterial community structure of a three-stage rotating bioelectrochemical contactor

    KAUST Repository

    Sayess, Rassil R.

    2013-02-01

    Integrating microbial fuel cell (MFC) into rotating biological contactor (RBC) creates an opportunity for enhanced removal of COD and nitrogen coupled with energy generation from wastewater. In this study, a three-stage rotating bioelectrochemical contactor (referred to as RBC-MFC unit) integrating MFC with RBC technology was constructed for simultaneous removal of carbonaceous and nitrogenous compounds and electricity generation from a synthetic medium containing acetate and ammonium. The performance of the RBC-MFC unit was compared to a control reactor (referred to as RBC unit) that was operated under the same conditions but without current generation (i.e. open-circuit mode). The effect of hydraulic loading rate (HLR) and COD/N ratio on the performance of the two units was investigated. At low (3.05 gCOD g-1N) and high COD/N ratio (6.64 gCOD g-1N), both units achieved almost similar COD and ammonia-nitrogen removal. However, the RBC-MFC unit achieved significantly higher denitrification and nitrogen removal compared to the RBC unit indicating improved denitrification at the cathode due to current flow. The average voltage under 1000 Ω external resistance ranged between 0.03 and 0.30 V and between 0.02 and 0.21 V for stages 1 and 2 of the RBC-MFC unit. Pyrosequencing analysis of bacterial 16S rRNA gene revealed high bacterial diversity at the anode and cathode of both units. Genera that play a role in nitrification (Nitrospira; Nitrosomonas), denitrification (Comamonas; Thauera) and electricity generation (Geobacter) were identified at the electrodes. Geobacter was only detected on the anode of the RBC-MFC unit. Nitrifiers and denitrifiers were more abundant in the RBC-MFC unit compared to the RBC unit and were largely present on the cathode of both units suggesting that most of the nitrogen removal occurred at the cathode. © 2012 Elsevier Ltd.

  17. Energy and chemical efficient nitrogen removal at a full-scale MBR water reuse facility

    Directory of Open Access Journals (Sweden)

    Jianfeng Wen

    2015-02-01

    Full Text Available With stringent wastewater discharge limits on nitrogen and phosphorus, membrane bioreactor (MBR technology is gaining popularity for advanced wastewater treatment due to higher effluent quality and smaller footprint. However, higher energy intensity required for MBR plants and increased operational costs for nutrient removal limit wide application of the MBR technology. Conventional nitrogen removal requires intensive energy inputs and chemical addition. There are drivers to search for new technology and process control strategies to treat wastewater with lower energy and chemical demand while still producing high quality effluent. The NPXpress is a patented technology developed by American Water engineers. This technology is an ultra-low dissolved oxygen (DO operation for wastewater treatment and is able to remove nitrogen with less oxygen requirements and reduced supplemental carbon addition in MBR plants. Jefferson Peaks Water Reuse Facility in New Jersey employs MBR technology to treat municipal wastewater and was selected for the implementation of the NPXpress technology. The technology has been proved to consistently produce a high quality reuse effluent while reducing energy consumption and supplemental carbon addition by 59% and 100%, respectively. Lab-scale kinetic studies suggested that NPXpress promoted microorganisms with higher oxygen affinity. Process modelling was used to simulate treatment performance under NPXpress conditions and develop ammonia-based aeration control strategy. The application of the ammonia-based aeration control at the plant further reduced energy consumption by additional 9% and improved treatment performance with 35% reduction in effluent total nitrogen. The overall energy savings for Jefferson Peaks was $210,000 in four years since the implementation of NPXpress. This study provided an insight in design and operation of MBR plants with NPXpress technology and ultra-low DO operations.

  18. Catalyst-Packed Non-Thermal Plasma Reactor for Removal of Nitrogen Oxides

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A single-stage plasma-catalytic reactor in which catalytic materials were packedwas used to remove nitrogen oxides. The packing material was scoria being made of various metaloxides including A12O3, MgO, TiO2, etc. Scoria was able to act not only as dielectric pelletsbut also as a catalyst in the presence of reducing agent such as ethylene and ammonia. Withoutplasma discharge, scoria did not work well as a catalyst in the temperature range of 100 °Cto 200 °C, showing less than 10% of NOx removal efficiency. When plasma is produced inside thereactor, the NOx removal efficiency could be increased to 60% in this temperature range.

  19. Removal of Nitrogen Oxides in Diesel Engine Exhaust by Plasma Assisted Molecular Sieves

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper reports the studies conducted on removal of oxides of nitrogen (NOx) from diesel engine exhaust using electrical discharge plasma combined with adsorbing materials such as molecular sieves. This study is being reported for the first time. The exhaust is taken from a diesel engine of 6 kW under no load conditions. The characteristic behavior of a pulse energized dielectric barrier discharge reactor in the diesel exhaust treatment is reported. The NOx removal was not significant (36%) when the reactor without any packing was used. However, when the reactor was packed with molecular sieves (MS -3A, -4A & -13X), the NOx removal efficiency was increased to 78% particularly at a temperature of 200 o C. The studies were conducted at different temperatures and the results were discussed.

  20. Advanced nitrogen removal using pilot-scale SBR with intelligent control system built on three layer network

    Institute of Scientific and Technical Information of China (English)

    YANG Qing; WANG Shuying; YANG Anming; GUO Jianhua; BO Fengyang

    2007-01-01

    Since eutrophication has become increasingly severe in China,nitrogen and phosphorous have been the concern of wastewater treatment,especially nitrogen removal.The stabilization of the intelligent control system and nitrogen removal efficiency were investigated in a pilot-scale aerobic-anoxic sequencing batch reactor(SBR)with a treatment capacity of 60 m3/d.Characteristic points on the profiles of dissolved oxygen(DO),pH,and oxidation reduction potential(ORP)could exactly reflect the process of nitrification and denitrification.Using the intelligent control system not only could save energy,but also could achieve advanced nitrogen removal.Applying the control strategy water quality of the effluent could stably meet the national first discharge standard during experiment of 10 months.Even at low temperature(t=13℃),chemical oxygen demand(COD)and total nitrogen(TY)in the effluent were under 50 and 5 mg/L,respectively.

  1. Present and perspective of enhanced biological phosphorus removal process; Seibutsugakuteki rin jokyoho no genjo to kadai

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, K. [National Inst. of Bioscience and Human-Technology, Tsukuba (Japan)

    1997-02-05

    Biological phosphorus removal process utilizing anaerobic and aerobic conditions, mechanism of phosphorus removal, and microbes relating to phosphorus removal are outlined, and future problems are discussed. By mixing waste water and sludge under anaerobic condition followed by treatment under aerobic condition, phosphorus content in sludge increases to enable biological phosphorus removal. More microbes with high polyphosphorus accumulating performance are acquired by the anaerobic/aerobic process than other microbes with the result of their preferential increase, and the process has high phosphorus removal characteristic than the general treatment process. Microbes relating to phosphorus removal, immobilization of polyphosphate accumulating microbes, and phosphorus acquiring and releasing characteristics of immobilized mycelium are discussed. Application of gel entrapped immobilized mycelium to phosphorus removal and problems in biological phosphorus removing methods are described. 18 refs., 12 figs.

  2. Biological removal of iron and manganese in rapid sand filters - Process understanding of iron and manganese removal

    DEFF Research Database (Denmark)

    Lin, Katie

    biological processes and the interaction between them. Some studies have indicated a direct competition between iron and ammonium removal when oxygen is limited, and both processes may have a negative effect on the manganese removal (de Vet et al., 2009; Tekerlekopoulou et al., 2008). However the reasons for.......g. flocculation) and physical (e.g. membrane filtration) based technologies. The removal of dissolved manganese and iron is important. If manganese and iron enter the distribution system, the water will become coloured and have a metallic taste, and it may cause problems in the distribution network due to...... precipitation and corrosion. Manganese and iron can either be removed physico-chemically or biologically or combined. The physico-chemical oxidation and precipitation of manganese can theoretically be achieved by aeration, but this process is slow unless pH is raised far above neutral, making the removal of...

  3. Exploring the Shift in Structure and Function of Microbial Communities Performing Biological Phosphorus Removal.

    Science.gov (United States)

    Mao, Yanping; Wang, Zhiping; Li, Liguan; Jiang, Xiaotao; Zhang, Xuxiang; Ren, Hongqiang; Zhang, Tong

    2016-01-01

    A sequencing batch reactor fed mainly by acetate was operated to perform enhanced biological phosphorus removal (EBPR). A short-term pH shock from 7.0 to 6.0 led to a complete loss of phosphate-removing capability and a drastic change of microbial communities. 16S rRNA gene pyrosequencing showed that large proportions of glycogen accumulating organisms (GAOs) (accounted for 16% of bacteria) bloomed, including Candidatus Competibacter phosphatis and Defluviicoccus-related tetrad-forming organism, causing deteriorated EBPR performance. The EBPR performance recovered with time and the dominant Candidatus Accumulibacter (Accumulibacter) clades shifted from Clade IIC to IIA while GAOs populations shrank significantly. The Accumulibacter population variation provided a good opportunity for genome binning using a bi-dimensional coverage method, and a genome of Accumulibacter Clade IIC was well retrieved with over 90% completeness. Comparative genomic analysis demonstrated that Accumulibacter clades had different abilities in nitrogen metabolism and carbon fixation, which shed light on enriching different Accumulibacter populations selectively. PMID:27547976

  4. [Removal efficiency of nitrogen in aerobic/anaerobic subsurface flow constructed wetlands].

    Science.gov (United States)

    Li, Feng-Min; Shan, Shi; Wang, Hao-Yun; Song, Ni; Wang, Zhen-Yu

    2011-01-01

    In order to adjust the dissolved oxygen in the traditional subsurface flow constructed wetlands (SFCWs) and increase the purification efficiency of sewage water, the traditional SFCWs were divided into different sections with enhanced functions. Different kinds of aerobic/anaerobic SFCWs were designed to study the influence of ratio and location of aerobic/anaerobic, artificial aeration and other factors on the nitrogen in effluent. The purification efficiency of the water in this study was compared with that in traditional SFCWs. The results showed that the removal efficiencies of NH4(+)-N and TN in traditional SFCWs were 18.4% and 40.6% but 99.7% and 50.7% in aerobic/anaerobic/aerobic SFCWs with aeration (O-A-O SFCWs with aeration) treatment. Aeration in the front and in the rear, and anaerobic treatment in the middle was used in this treatment. Removal efficiency of NH4(+)-N in O-A-O SFCWs with aeration treatment was 100%, while that of O-A-O SFCWs without aeration was about 50%. The removal efficiencies of NH4(+) -N in new SFCWs with aeration in the front and in the rear were increased by 82.81% and 17.91% but 73.16% in the middle. It shows that aeration can significantly improve the removal efficiency of nitrogen, especially NH4(+)-N. Aeration in the front and back can greatly improve the removal efficiency NH4(+)-N and TN. But aeration resulting to oxygen-rich environment is not conducive to the denitrification, which will be an important factor of limiting the TN removal efficiency. PMID:21404680

  5. [Effect of Intermittent Aeration on Nitrogen Removal Efficiency in Vertical Subsurface Flow Constructed Wetland].

    Science.gov (United States)

    Wang, Jian; Li, Huai-zheng; Zhen, Bao-chong; Liu, Zhen-dong

    2016-03-15

    One-stage vertical subsurface flow constructed wetlands (CWs) were used to treat effluent from grit chamber in municipal wastewater treatment plant. The CW was divided into aerobic zone and anoxic zone by means of raising the effluent level and installing a perforated pipe. Two parameters (the ratio of aeration time and nonaeration time, aeration cycle) were optimized in the experiment to enhance nitrogen removal efficiency. The results suggested that the removal rates of COD and NH₄⁺-N increased while TN showed a trend of first increasing and then decreasing with the increasing ratio. When the ratio was 3:1, the C/N value in the anoxic zone was 4. 8. And the TN effluent concentration was 15.8 mg · L⁻¹ with the highest removal rate (62.1%), which was increased by 12.7% compared with continuous aeration. As the extension of the aeration cycle, the DO effluent concentration as well as the removal rates of COD and NH: -N declined gradually. The TN removal rate reached the maximum (65.5%) when the aeration cycle was 6h. However, the TN removal rate dropped rapidly when the cycle exceeded the hydraulic retention time in the anoxic zone. PMID:27337890

  6. Using sludge fermentation liquid to reduce the inhibitory effect of copper oxide nanoparticles on municipal wastewater biological nutrient removal.

    Science.gov (United States)

    Su, Yinglong; Chen, Yinguang; Zheng, Xiong; Wan, Rui; Huang, Haining; Li, Mu; Wu, Lijuan

    2016-08-01

    The deterioration of biological nutrient removal (BNR) can occur with the release of engineering nanomaterials into wastewater treatment plants (WWTPs). Also, large amounts of waste sludge are generated in WWTPs, which can be reutilized as a useful resource. In this study, the use of sludge fermentation liquid to reduce CuO nanoparticles (NPs) toxicity to municipal wastewater BNR was reported. In the BNR system supplemented with sodium acetate, which was widely used as additional carbon source of municipal wastewater in literatures, the appearance of 2.5 mg/L CuO NPs for 5.5 h decreased the total nitrogen (TN) removal efficiency from 81.4% to 59.0%, but the TN removal was recovered to 78.7% after sodium acetate was replaced by sludge fermentation liquid. It was found that CuO NPs induced excessive generation of reactive nitrogen species (RNS), which led to the disorder of redox status, low levels of energy and reduction equivalents generations, and deterioration of denitrification. Further investigation revealed that cysteine in fermentation liquid played a vital biological role in reducing nanotoxicity by facilitating the synthesis of glutathione, which reduced excessive RNS generation, increased key proteins expression, guaranteed the metabolisms of intracellular energy and substrate smoothly, and finally recovered the BNR performance. PMID:27161888

  7. Combined organic matter and nitrogen removal from a chemical industry wastewater in a two-stage MBBR system.

    Science.gov (United States)

    Cao, S M S; Fontoura, G A T; Dezotti, M; Bassin, J P

    2016-01-01

    Pesticide-producing factories generate highly polluting wastewaters containing toxic and hazardous compounds which should be reduced to acceptable levels before discharge. In this study, a chemical industry wastewater was treated in a pre-denitrification moving-bed biofilm reactor system subjected to an increasing internal mixed liquor recycle ratio from 2 to 4. Although the influent wastewater characteristics substantially varied over time, the removal of chemical oxygen demand (COD) and dissolved organic carbon was quite stable and mostly higher than 90%. The highest fraction of the incoming organic matter was removed anoxically, favouring a low COD/N environment in the subsequent aerobic nitrifying tank and thus ensuring stable ammonium removal (90-95%). However, during pH and salt shock periods, nitrifiers were severely inhibited but gradually restored their full nitrifying capability as non-stressing conditions were reestablished. Besides promoting an increase in the maximum nitrification potential of the aerobic attached biomass from 0.34 to 0.63 mg [Formula: see text], the increase in the internal recycle ratio was accompanied by an increase in nitrogen removal (60-78%) and maximum specific denitrification rate (2.7-3.3 mg NOx(-)--N). Total polysaccharides (PS) and protein (PT) concentrations of attached biomass were observed to be directly influenced by the influent organic loading rate, while the PS/PT ratio mainly ranged from 0.3 to 0.5. Results of Microtox tests showed that no toxicity was found in the effluent of both the anoxic and aerobic reactors, indicating that the biological process was effective in removing residual substances which might adversely affect the receiving waters' ecosystem. PMID:26086717

  8. Nitrogen removal from landfill leachate via ex situ nitrification and sequential in situ denitrification

    International Nuclear Information System (INIS)

    Ex situ nitrification and sequential in situ denitrification represents a novel approach to nitrogen management at landfills. Simultaneous ammonia and organics removal was achieved in a continuous stirred tank reactor (CSTR). The results showed that the maximum nitrogen loading rate (NLR) and the maximum organic loading rate (OLR) was 0.65 g N l-1 d-1 and 3.84 g COD l-1 d-1, respectively. The ammonia and chemical oxygen demand (COD) removal was over 99% and 57%, respectively. In the run of the CSTR, free ammonia (FA) inhibition and low dissolved oxygen (DO) were found to be key factors affecting nitrite accumulation. In situ denitrification was studied in a municipal solid waste (MSW) column by recalculating nitrified leachate from CSTR. The decomposition of MSW was accelerated by the recirculation of nitrified leachate. Complete reduction of total oxidized nitrogen (TON) was obtained with maximum TON loading of 28.6 g N t-1 TS d-1 and denitrification was the main reaction responsible. Additionally, methanogenesis inhibition was observed while TON loading was over 11.4 g N t-1 TS d-1 and the inhibition was enhanced with the increase of TON loading

  9. Autotrophic nitrogen removal from black water: calcium addition as a requirement for settleability.

    Science.gov (United States)

    de Graaff, M S; Temmink, H; Zeeman, G; van Loosdrecht, M C M; Buisman, C J N

    2011-01-01

    Black (toilet) water contains half of the organic load in the domestic wastewater, as well as the major fraction of the nutrients nitrogen and phosphorus. When collected with vacuum toilets, the black water is 25 times more concentrated than the total domestic wastewater stream, i.e. including grey water produced by laundry, showers etc. A two-stage nitritation-anammox process was successfully employed and removed 85%-89% of total nitrogen in anaerobically treated black water. The (free) calcium concentration in black water was too low (42 mg/L) to obtain sufficient granulation of anammox biomass. The granulation and retention of the biomass was improved considerably by the addition of 39 mg/L of extra calcium. This resulted in a volumetric nitrogen removal rate of 0.5 gN/L/d, irrespective of the two temperatures of 35 °C and 25 °C at which the anammox reactors were operated. Nitrous oxide, a very strong global warming gas, was produced in situations of an incomplete anammox conversion accompanied by elevated levels of nitrite. PMID:20822793

  10. Municipal wastewater treatment by biofiltration: comparisons of various treatment layouts. Part 1: assessment of carbon and nitrogen removal.

    Science.gov (United States)

    Rocher, Vincent; Paffoni, Catherine; Gonçalves, Alexandre; Guérin, Sabrina; Azimi, Sam; Gasperi, Johnny; Moilleron, Régis; Pauss, André

    2012-01-01

    One of the largest wastewater treatment plants in the Paris conurbation (240,000 m(3)/d) has been studied over several years in order to provide technical and economical information about biological treatment by biofiltration. Biofiltration systems are processes in which carbon and nitrogen pollution of wastewater are treated by ascendant flow through immersed fixed cultures. This paper, focused on technical information, aims: (1) to compare performances of the three biological treatment layouts currently used in biofiltration systems: upstream denitrification (UD), downstream denitrification (DD) and combined upstream-downstream denitrification (U-DD) layouts; and (2) to describe in detail each treatment step. Our study has shown that more than 90% of the carbon and ammoniacal pollution is removed during biological treatment, whatever the layout used. Nitrate, produced during nitrification, is then reduced to atmospheric nitrogen. This reduction is more extensive when the denitrification stage occurs downstream from the treatment (DD layout with methanol addition), whereas it is only partial when it is inserted upstream from the treatment (UD layout - use of endogenous carbonaceous substrate). So, the UD layout leads to a nitrate concentration that exceeds the regulatory threshold in the effluent, and the treatment must be supplemented with a post-denitrification step (U-DD layout). Our work has also shown that the optimal ammonium-loading rate is about 1.1-1.2 kg N-NH(4)(+) per m(3) media (polystyrene) and day. For denitrification, the optimal nitrate-loading rate is about 2.5 kg N per m(3) media (expanded clay) and day in the case of DD with methanol, and is about 0.25 kg N-NO(3)(-) per m(3) media and day in the case of UD with exogenous carbonaceous substrate. PMID:22508136

  11. Biochar Addition to Stormwater Treatment Media for Enhanced Removal of Nitrogen

    Science.gov (United States)

    Imhoff, P. T.; Jin, J.; Tian, J.; Chiu, P.; Guo, M.

    2015-12-01

    Urban stormwater management systems, such as bioretention facilities, require substantial land area and are often ineffective in removing nitrogen. This project seeks to improve nitrogen removal in bioretention media by modifying the hydraulic and treatment characteristics of the infiltration medium with biochar addition. A commercial wood biochar pyrolyzed from Southern Yellow Pine at 500°C was used. Laboratory experiments demonstrated that biochar addition to a typical bioretention medium (soil-mix: 4% saw dust, 88% sand, 8% clay) increased ammonium sorption at typical stormwater concentrations (2 mg/L) by a factor of 6, total porosity by 16.6%, and water retention at most matric potentials. The effect of the biochar-amended medium on nitrate removal was evaluated in pilot-scale experiments. Side-by-side experimental cells (91 cm dia., 1.2 m deep) were constructed to treat stormwater runoff from a parking lot. The control cell contained 100% soil mix while the biochar cell contained 4% biochar and 96% soil-mix by mass. Treatment media were 76.2 cm in depth and overlain by 5.1 cm of wood mulch in both cells, with a water table maintained at the bottom of the treatment zones. Cells were instrumented with TDR moisture sensors, pressure transducers, and redox and temperature sensors. Two pilot-scale experiments were conducted that included a bromide tracer and nitrate with a hydraulic loading of 5.5cm/h for 24 h in early spring and 36 h in summer. Effluent was continuously sampled for nitrogen compounds during these tests. Tracer tests and TDR measurements showed that biochar increased the average volumetric water content of the vadose zone by 14.7% and the mean residence time by 12.6%. For the spring field test at 14°C, nitrate in the control cell effluent increased by 6.1% but decreased by 43.5% for the biochar cell. For the summer field test at 22°C, 30.6% and 84.7% of influent nitrate was removed in the control and biochar cells, respectively. In the summer

  12. Aerobic granulation and nitrogen removal with the effluent of internal circulation reactor in start-up of a pilot-scale sequencing batch reactor.

    Science.gov (United States)

    Wei, Dong; Si, Wei; Zhang, Yongfang; Qiao, Zhuangming; Yao, Zhenxing; Zhao, Wei; Zhao, Jie; Chen, Guodong; Wei, Qin; Du, Bin

    2012-11-01

    Aerobic granular sludge was successfully cultivated with the effluent of internal circulation (IC) reactor in a pilot-scale sequencing batch reactor (SBR) using activated sludge as seeding sludge. N removal was investigated in the start-up of aerobic granulation process. Initially, the phenomenon of partial nitrification was observed and nitrite accumulation rates (NO(2) (-)-N/NO (x) (-) -N) were between 84.6 and 99.1 %. It was potentially caused by ammonium oxidizing bacteria (AOB) in the seeding activated sludge, high external environmental temperature (~32 °C) and free ammonia (FA) concentration. After 50 days' running, the aerobic granules-based bioreactor demonstrated perfect performance in simultaneous removal of organic matter and ammonia nitrogen, and average removal efficiencies were maintained above 93 and 96 %, respectively. The maximum nitrogen removal efficiency of 83.1 % was achieved after the formation of aerobic granules. The average diameter of mature aerobic granular sludge mostly ranged from 0.5 to 1.0 mm. Furthermore, one typical cyclic test indicated that pH and DO profiles could be used as effective parameters for biological reactions occurring in the aerobic/anoxic process. The obtained results could provide further information on the cultivation of aerobic granular sludge with practical wastewater, especially with regard to nitrogen-rich industrial wastewater. PMID:22562444

  13. Intensified nitrogen and phosphorus removal in a novel electrolysis-integrated tidal flow constructed wetland system.

    Science.gov (United States)

    Ju, Xinxin; Wu, Shubiao; Zhang, Yansheng; Dong, Renjie

    2014-08-01

    A novel electrolysis-integrated tidal flow constructed wetland (CW) system was developed in this study. The dynamics of intensified nitrogen and phosphorus removal and that of hydrogen sulphide control were evaluated. Ammonium removal of up to 80% was achieved with an inflow concentration of 60 mg/L in wetland systems with and without electrolysis integration. Effluent nitrate concentration decreased from 2 mg/L to less than 0.5 mg/L with the decrease in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2) in the electrolysis-integrated wetland system, thus indicating that the current intensity of electrolysis plays an important role in nitrogen transformations. Phosphorus removal was significantly enhanced, exceeding 95% in the electrolysis-integrated CW system because of the in-situ formation of a ferric iron coagulant through the electro-dissolution of a sacrificial iron anode. Moreover, the electrolyzed wetland system effectively inhibits sulphide accumulation as a result of a sulphide precipitation coupled with ferrous-iron electro-dissolution and/or an inhibition of bacterial sulphate reduction under increased aerobic conditions. PMID:24784452

  14. Nitrogen removal properties in a continuous marine anammox bacteria reactor under rapid and extensive salinity changes.

    Science.gov (United States)

    Wei, Qiaoyan; Kawagoshi, Yasunori; Huang, Xiaowu; Hong, Nian; Van Duc, Luong; Yamashita, Yuki; Hama, Takehide

    2016-04-01

    Salinity tolerance is one of the most important factors for the application of bioreactors to high-salinity wastewater. Although marine anammox bacteria (MAB) might be expected to tolerate higher salinities than freshwater anammox bacteria, there is little information on the effects of salinity on MAB activity. This study aimed to reveal the nitrogen removal properties in a continuous MAB reactor under conditions of rapid and extensive salinity changes. The reactor demonstrated stable nitrogen removal performance with a removal efficiency of over 85% under salinity conditions ranging from 0 to 50 g/L NaCl. The reactor performance was also well maintained, even though the salinity was rapidly changed from 30 to 50 g/L and from 30 to 0 g/L. Other evidence suggested that the seawater medium used contained components essential for effective MAB performance. Bacterial community analysis using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) showed that planctomycete UKU-1, the dominant MAB species in the inoculum, was the main contributor to anammox activity under all conditions. The PCR-DGGE using a universal bacterial primer set showed different DNA band patterns between the reactor biomass sample collected under conditions of 75 g/L NaCl and all other conditions (0, 30, 50 and freshwater-medium). All DNA sequences determined were very similar to those of bacterial species from marine environments, anaerobic environments, or wastewater-treatment facilities. PMID:26845464

  15. Catalytic pleat filter bags for combined particulate separation and nitrogen oxides removal from flue gas streams

    International Nuclear Information System (INIS)

    The development of a high temperature catalytically active pleated filter bag with hybrid filter equipment for the combined removal of particles and nitrogen oxides from flue gas streams is presented. A special catalyst load in stainless steel mesh cartridge with a high temperature pleated filter bag followed by optimized catalytic activation was developed to reach the required nitrogen oxides levels and to maintain the higher collection efficiencies. The catalytic properties of the developed high temperature filter bags with hybrid filter equipment were studied and demonstrated in a pilot scale test rig and a demonstration plant using commercial scale of high temperature catalytic pleated filter bags. The performance of the catalytic pleated filter bags were tested under different operating conditions, such as filtration velocity and operating temperature. Moreover, the cleaning efficiency and residual pressure drop of the catalyst loaded cartridges in pleated filter bags were tested. As result of theses studies, the optimum operating conditions for the catalytic pleated filter bags are determined. (author)

  16. Chapter 3. Use of tracer technology in biological nitrogen fixation research

    International Nuclear Information System (INIS)

    This chapter discusses the use of tracer technology in the measurement and use of biological nitrogen fixation by leguminous crops. Whether grown as pulses for grain, as green manure, as pastures or as the tree components of agro-forestry systems, the value of leguminous crops lies in their ability to fix atmospheric N2, thus reducing the use of expensive fertilizer-N and enhancing soil fertility. Nitrogen-fixing legumes provide the basis for developing sustainable farming systems that incorporate integrated nutrient management. Use of nitrogen-15 lends understanding of the dynamics and interactions between various pools in agricultural systems, including nitrogen fixation by legumes and utilization of soil and fertilizer nitrogen by crops in general, both in sole and mixed cropping systems (3.1). 15N isotope dilution methodology has been found to be particularly useful to quantify and to enhance biological nitrogen fixation in leguminous crops (3.2). The final section of this chapter explores the data required to quantify a system's nitrogen balance, using crop legumes as an example, with particular emphasis on the methodologies that might be used to quantify the below ground contributions of nitrogen associated with roots and root nodules (3.3). (author)

  17. Enzymology of biological nitrogen fixation. Final report, May 1, 1987--April 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    Biological nitrogen fixation is of central importance in the earth`s nitrogen economy. Fixation of nitrogen is accomplished by a variety of microorganisms, all of them procaryotic. Some operate independently and some function symbiotically or associatively with photosynthesizing plants. Biological nitrogen fixation is accomplished via the reaction: N{sub 2} + 8H{sup +} + 8e{sup {minus}} {yields} 2NH{sub 3} + H{sub 2}. This reaction requires a minimum of 16 ATP under ideal laboratory conditions, so it is obvious that the energy demand of the reaction is very high. When certain nitrogen-fixing organisms are supplied fixed nitrogen (e.g., ammonium) the organisms use the fixed nitrogen and turn off their nitrogenase system, thus conserving energy. When the fixed nitrogen is exhausted, the organism reactivates its nitrogenase. The system is turned off by dinitrogenase reductase ADP-ribosyl transferase (DRAT) and turned back on by dinitrogenase reductase-activating glycohydrolase (DRAG). The authors have investigated the details of how DRAT and DRAG are formed, how they function, and the genetics of their formation and operation.

  18. A GAO hiding among the PAO: The role of the Propionivibrio spp. in biological phosphorus removal

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Albertsen, Mads; Stokholm-Bjerregaard, Mikkel;

    Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater...

  19. Nitrogen and carbon export from urban areas through removal and export of litterfall

    International Nuclear Information System (INIS)

    We found that up to 52 ± 17% of residential litterfall carbon (C) and nitrogen (N; 390.6 kg C and 6.5 kg N ha−1 yr−1) is exported through yard waste removed from the City of Boston, which is equivalent to more than half of annual N outputs as gas loss (i.e. denitrification) or leaching. Our results show that removing yard waste results in a substantial decrease in N inputs to urban areas, which may offset excess N inputs from atmospheric deposition, fertilizer application and pet waste. However, export of C and N via yard waste removal may create nutrient limitation for some vegetation due to diminished recycling of nutrients. Removal of leaf litter from residential areas disrupts nutrient cycling and residential yard management practices are an important modification to urban biogeochemical cycling, which could contribute to spatial heterogeneity of ecosystems that are either N limited or saturated within urban ecosystems. - Highlights: • We monitored yard waste bags for one complete fall yard waste collection season. • 52% of residential litterfall C and N is exported annually from the City of Boston. • Litterfall export may create nutrient limitation hotspots in urban ecosystems. • C and N export through litterfall collection modifies urban biogeochemical cycling. - Litterfall removal leads to C and N export from urban ecosystems and disrupts nutrient cycling, showing that this activity is an important modification to urban biogeochemical cycling

  20. Ammonium nitrogen removal in batch cultures treating digested piggery wastewater with microalgae Oedogonium sp.

    Science.gov (United States)

    Wang, Haiping; Hu, Zhiquan; Xiao, Bo; Cheng, Qunpeng; Li, Fanghua

    2013-01-01

    Due to the nutrient characteristics of the high concentration of available ammonium in digested piggery wastewater (DPW), microalgae can be used to treat DPW before its final discharge. Four green microalgae (Hydrodictyaceae reticulatum Lag, Scenedesmus obliquus, Oedogonium sp. and Chlorella pyrenoidosa) and three blue-green algae (Anabaena flos-aquae, Oscillatoria amoena Gom and Spirulina platensis) were used to remove the nutrients (N, P, C), especially ammonium nitrogen (NH4(+)-N), from diluted DPW with 300 mg/L algae density in batch tests. The microalgae with the best NH4(+)-N nutrient removal was then selected for further optimization of the variables to improve NH4(+)-N removal efficiency using a central composite design (CCD) experiment. Taking into account the nutrient removal efficiency, Oedogonium sp. showed the best performance (reduction of 95.9% NH4(+)-N, 92.9% total phosphorus (TP) and 62.5% chemical oxygen demand (COD)) based on the results of the batch tests. The CCD results suggested that the optimal values of variables were initial Oedogonium sp. density of 399.2 mg/L and DPW diluted by 16.3, while the predicted value of NH4(+)-N removal efficiency obtained was 97.0%. PMID:23863416

  1. Identification of a Novel Group of Bacteria in Sludge from a Deteriorated Biological Phosphorus Removal Reactor

    OpenAIRE

    Nielsen, Alex T.; Liu, Wen-Tso; Filipe, Carlos; Grady, Leslie; Molin, Søren; Stahl, David A

    1999-01-01

    The microbial diversity of a deteriorated biological phosphorus removal reactor was investigated by methods not requiring direct cultivation. The reactor was fed with media containing acetate and high levels of phosphate (P/C weight ratio, 8:100) but failed to completely remove phosphate in the effluent and showed very limited biological phosphorus removal activity. Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA was used to investigate the bacterial diversit...

  2. [Effect of intermittent artificial aeration on nitrogen and phosphorus removal in subsurface vertical-flow constructed wetlands].

    Science.gov (United States)

    Tang, Xian-qiang; Li, Jin-zhong; Li, Xue-Ju; Liu, Xue-gong; Huang, Sui-liang

    2008-04-01

    Shale and T. latifolia were used as subsurface vertical-flow constructed wetland substrate and vegetation for eutrophic Jin River water treatment, and investigate the effect of intermittent aeration on nitrogen and phosphorus removal. In this study, hydraulic loading rate was equal to 800 mm/d, and ratio of air and water was 5:1. During the entire running period, maximal monthly mean ammonia-nitrogen (NH4+ -N), total nitrogen (TN), soluble reactive phosphorus (SRP) and total phosphorus (TP) removal rates were observed in August 2006. In contrast to the non-aerated wetland, aeration enhanced ammonia-nitrogen, total nitrogen, soluble reactive phosphorus and total phosphorus removal: 10.1%, 4.7%, 10.2% and 8.8% for aeration in the middle, and 25.1%, 10.0%, 7.7% and 7.4% for aeration at the bottom of the substrate, respectively. However, aeration failed to improve the nitrate-nitrogen removal. During the whole experimental period, monthly mean NO3(-) -N removal rates were much lower for aerated constructed wetlands (regarding aeration in the middle and at the bottom) than those for non-aerated system. After finishing the experiment, aboveground plant biomass (stems and leaves) of T. latifolia was harvested, and its weight and nutrient content (total nitrogen and total phosphorus) were measured. Analysis of aboveground plant biomass indicated that intermittent aeration restrained the increase in biomass but stimulated assimilation of nitrogen and phosphorus into stems and leaves. Additional total nitrogen removal of 11.6 g x m(-2) and 12.6 g x m(-2) by aboveground T. latifolia biomass for intermittent artificial aeration in the middle and at the bottom of the wetland substrate, respectively, was observed. PMID:18637335

  3. Performance of Combined Anaerobic-Aerobic System in Removal of Nitrogen in the Treatment of Sanitary Sewage

    Directory of Open Access Journals (Sweden)

    Mário Luiz Rodrigues Foco

    2014-10-01

    Full Text Available This paper describes the evaluation of the performance of an anaerobic-aerobic system, consisting of anaerobic filter (AF followed by biological aerated filter (BAF, operated with and without recirculation of treated effluent to mitigate the adverse effects of organic concentrations on nitrification and promote the removal of Total Nitrogen in anoxic ambient. In the first two steps, the application of the organic loading rate (OLR on BAF ranged from 0.49 ± 0.27 and 0.31 ± 0.08 kg BOD m-3 d-1 due to the reduction of surface application rate of 60 to 44 m3 m-2 d-1. In the third stage, with recirculation, OLR and surface application rate were 0.29 ± 0.02 kg BOD m-3 d-1 and 65.8 m3 m-2 d-1, allowing the system to reduce 43 ± 10% of average initial concentration of 72 mg L-1 Total Nitrogen. The application of organic loading rates in BAS, more than 0.30 kg BOD m-3 d-1 inhibited nitrification due to competition for oxygen

  4. Bio-chemical process for nitrogen and phosphorus removal by draining out anaerobic rich phosphate supernatant in ERP-SBR system

    Institute of Scientific and Technical Information of China (English)

    JIFangying; XUXiaoyi; LUOGuyuan

    2003-01-01

    The method of fixed phosphate coming from anaerobic reactor by the auxiliary chemical process is applied in External Recycle Process-SBR (ERP-SBR). This process changes the model of draining out activated sludge in the traditional biological phosphorus removal system to discharge anaerobic poly-phosphate supernatant. This process eliminates the contradiction of control for Solid Removal Time (SRT) in process of biological nitrogen and phosphorus removal. It can obtain high removal efficiency of nitrogen(N) and phosphorus(P) in longer SRT. Experiment results show that: when SRT=50 ~ 80 d, TN=28.6~ 58.3 mg/L, TP=5.5~ 13.5 mg/L in influent, COD≤ 34mg/L, TN≤ 6.02 mg/L, PO43-≤0.23 mg/L in effluent. The amount of lime is only 5% of traditional methods. The phosphorus content in the chemical sludge is 12 %~15 % and the recycle of phosphorus can be realized easily.

  5. Removal of nitrogen from MBT residues by leachate recirculation in combination with intermittent aeration.

    Science.gov (United States)

    Tran, Hoai Nam; Münnich, Kai; Fricke, Klaus; Harborth, Peter

    2014-01-01

    Mechanical-biological treatment (MBT) techniques have been used to reduce the emission potential of waste before placement in landfills for a couple of years, especially in Europe. The main focus of MBT is on the reduction of native organic substances and not on nitrogen compounds. As a result, the concentrations of organic substances in leachate from MBT landfills are considerably reduced in comparison to leachates from municipal solid waste landfills, while the ammonia nitrogen concentrations remain at a high level. From the stabilization of old landfills it is well known that recirculation of leachate and supplementary aeration can reduce emissions to an acceptable level in a comparatively short time. In a series of laboratory-scale tests the efficiency of this technique for MBT residues was investigated under different boundary conditions. While the effect of leachate recirculation is also well known for MBT residues, the additional aeration has so far not been investigated. The results show that this technique has only a limited influence on the reduction of organic carbon compounds. In view of nitrogen compounds, only the additional aeration during recirculation shows a strong effect on the quality of leachate, in which the concentrations of ammonium and total nitrogen are reduced by more than 90%. The results indicate that by using simple techniques the long-term emission behavior of MBT residues can be quickly reduced to an acceptable level. PMID:24293068

  6. Removal of nitrogen and phosphorus from dairy wastewater using constructed wetlands systems operating in batch

    OpenAIRE

    Ronaldo Rocha Bastos; Alisson Carraro Borges; Celso Bandeira de Melo Ribeiro; Henrique Vieira Mendonça

    2012-01-01

    This work presents the results of a study conducted for a period of seven months on the effectiveness of constructed wetland systems for the treatment of dairy wastewater aiming at removing, nitrogen and phosphorus. Six experimental systems were assembled with a net volume of 115 L using HDPE tanks, with length/width ratio of 2:1. In three of the systems, gravel 0 was used as substrate, while gravel 0 and sand was used in the three others, in the percentage of 80% and 20%, respectively. The s...

  7. New perspectives for the petroleum industry. Bioprocesses for the selective removal of sulphur, nitrogen and metals

    International Nuclear Information System (INIS)

    Fuel biocatalytic conversion is a process that removes, through selective enzyme-catalyzed reactions, sulphur, nitrogen and metals. The mild operating conditions, the specificity of reactions and the quality of coproducts (particularly the organo sulphur compounds, a source for the petrochemical industry) are just a few of the attractive aspects of this new technology which could open a new world of possibilities in the technology and in the environmental impact of fuels. The paper shows the state-of-the-art of the research and applications of bioprocesses to the petroleum field

  8. Start-up and microbial communities of a simultaneous nitrogen removal system for high salinity and high nitrogen organic wastewater via heterotrophic nitrification.

    Science.gov (United States)

    Chen, Jiahao; Han, Yi; Wang, Yingmu; Gong, Benzhou; Zhou, Jian; Qing, Xiaoxia

    2016-09-01

    In this study, a simultaneous nitrogen removal system for high salinity and high nitrogen organic wastewater was developed in a pressurized biofilm reactor. The result showed that under the air supply rate of 200Lh(-1), salinity of 3.0±0.2%, organic load of 10kgCODm(-3)d(-1) and nitrogen loading of 0.185kgm(-3)d(-1), the reactor started up rapidly and performed stably after 30days operation. Meanwhile, a simultaneous COD and nitrogen removal was achieved in the single-stage reactor, with COD, NH4(+)-N and TN removal efficiency of 97%, 99% and 98%, respectively. Denaturing gradient gel electrophoresis profile demonstrated that simultaneous nitrogen removal could be achieved through heterotrophic nitrification-aerobic denitrification, and the pivotal microorganisms were Flavobacterium phragmitis and Paracoccus denitrificans. The microbial community of salt-tolerant halophilic microorganisms was developed successfully. This study can provide a more efficient and feasible solution to treat high salinity organic wastewater. PMID:27240235

  9. Foliage plants for indoor removal of the primary combustion gases carbon monoxide and nitrogen dioxide

    Science.gov (United States)

    Wolverton, B. C.; Mcdonald, R. C.; Mesick, H. H.

    1985-01-01

    Foliage plants were evaluated for their ability to sorb carbon monoxide and nitrogen dioxide, the two primary gases produced during the combustion of fossil fuels and tobacco. The spider plant (Chlorophytum elatum var. vittatum) could sorb 2.86 micrograms CO/sq cm leaf surface in a 6 h photoperiod. The golden pothos (Scindapsus aureus) sorbed 0.98 micrograms CO/sq cm leaf surface in the same time period. In a system with the spider plant, greater than or equal to 99 percent of an initial concentration of 47 ppm NO2 could be removed in 6 h from a void volume of approximately 0.35 cu m. One spider plant potted in a 3.8 liter container can sorb 3300 micrograms CO and effect the removal of 8500 micrograms NO2/hour, recognizing the fact that a significant fraction of NO2 at high concentrations will be lost by surface sorption, dissolving in moisture, etc.

  10. Nitrogen removal from sludge dewatering effluent through anaerobic ammonia oxidation process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shao-hui; ZHENG Ping; HUA Yu-mei

    2005-01-01

    Anaerobic ammonia oxidation(Anammox) process is a novel and promising wastewater nitrogen removal process. The feasibility of transition of Anammox from denitrification and the performance of lab-scale Anammox biofilm reactor were investigated with sludge dewatering effluent. The results showed that Anammox process could be successfully started up after cultivation of denitrification biofilm and using it as inoculum. The transition of Anammox from denitrification was accomplished within 85 d. Anammox process was found suitable to remove ammonia from sludge dewatering effluent. The effluent ammonia concentration was detected to be 23.11 mgN/L at HRT of 28 h when influent ammonia concentration was fed 245 mgN/L, which was less than that for the national discharge standard Ⅱ (25 mgN/L) of 243.25 mg NH4+ -N/L and 288.31 mg NO2- -N/L.

  11. Economic and environmental evaluation of nitrogen removal and recovery methods from wastewater.

    Science.gov (United States)

    Lin, Yanzi; Guo, Miao; Shah, Nilay; Stuckey, David C

    2016-09-01

    The driver for waste-based economic growth is long-term strategic design, and a paradigm-shift from waste treatment to resource recovery. This study aims to use an integrated modelling approach to evaluate the holistic economic and environmental profiles of three alternative nitrogen removal and recovery methods integrated into wastewater treatment systems, including conventional nitrification-denitrification, Anammox, and the anaerobic ion exchange route, to provide insights into N recovery system designs which are key elements in building a sustainable circular economy. Our results suggest that ion exchange is a promising technology showing high N removal-recovery efficiency from municipal wastewater and delivering competitive sustainability scores. In comparison with the well-developed conventional route, ion exchange and Anammox are undergoing significant research and development; as highlighted in sensitivity analyses, there is considerable room for process design and optimisation of ion exchange systems to achieve economically and environmentally optimal performance. PMID:27005785

  12. Microbial community stratification in Membrane-Aerated Biofilm Reactors for Completely Autotrophic Nitrogen Removal

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Ruscalleda, Maël; Terada, Akihiko;

    bacterial granules or biofilms. In this sense, completely autotrophic nitrogen removal from high ammonium strength wastewater was achieved in a Membrane-Aereated Biofilm Reactor (MABR) in a single step. Here, a biofilm containing nitrifiers (Aerobic Ammonium and Nitrite Oxidizing Bacteria, AOB and NOB......Due to the necessity of a source of nitrite, most of the processes involving Anaerobic Ammonium Oxidation (Anammox) are based on a separated two-step process with a previous partial-nitritation reactor. However, these two processes can occur simultaneously in the same reactor by taking advantage of......, respectively) and Anaerobic Ammonium Oxidizing Bacteria (AnAOB) is grown on bubbleless aeration membranes to remove ammonium. Since oxygen permeates through the membrane-biofilm interface while ammonium diffuses into the biofilm from the biofilm-liquid interface, oxygen gradients can be established across the...

  13. History on the biological nitrogen fixation research in graminaceous plants: special emphasis on the Brazilian experience

    OpenAIRE

    José I. Baldani; Vera L.D. Baldani

    2005-01-01

    This review covers the history on Biological Nitrogen Fixation (BNF) in Graminaceous plants grown in Brazil, and describes research progress made over the last 40 years, most of whichwas coordinated by Johanna Döbereiner. One notable accomplishment during this period was the discovery of several nitrogen-fixing bacteria such as the rhizospheric (Beijerinckia fluminensis and Azotobacter paspali), associative (Azospirillum lipoferum, A. brasilense, A. amazonense) and the endophytic (Herbaspiril...

  14. Results of activated sludge plants applying enhanced biological phosphorus removal

    Energy Technology Data Exchange (ETDEWEB)

    Machado, A.; Pinto, M.; Neder, K.; Hoffmann, H.

    1989-02-01

    To stop the eutrophication in lakes and rivers, the input of nutrient and phosphorus compounds must be limited. The biological elimination of phosphorus describes a possibility, to reduce phosphorus in the biological stage of a treatment plant to a considerable extent. In this paper the process-system and the operation-results of a pilot plant and two municipal treatment plants are presented, where biological phosphorus reduction about 80% takes place without any constructional modifications.

  15. Biological nitrogen (N) fixation - The source of N nutrient to increase yield

    International Nuclear Information System (INIS)

    Nitrogen is an essential plant nutrient. It is the nutrient that is most commonly deficient, contributing to reduced agricultural yields throughout the world. Developing countries used more than 85 million metric tones of nitrogenous fertilizer in 2003, worth billions of US dollars. Such fertilizer expenditure can be significantly reduced by incorporating biological nitrogen fixed leguminous crops into a growing rotation. In leguminous crops, a symbiotic relationship between a bacterium called Rhizobium and legumes can provide large amounts of nitrogen to the plant and subsequently to soils where they are grown. In this process the bacteria form nodules on the root system and convert the nitrogen coming from air into molecules that can be absorbed by the plants. Beside their fertilizing properties, legumes are rich in protein and constitute a very important role in the human and animal nutrition. In the Soil Science Unit (SSU) of the FAO/IAEA Agriculture and Biotechnology Laboratory fellows from all over the world receive training in the use of 15N stable isotope techniques to optimise the nitrogen fixation. Several parameters such as the placement of the nodules on the legume root system, the amount of soil mineral nitrogen and phosphorus fertilizer applied and the temperature have an impact on the amount of nitrogen fixed by the plant. It is therefore important to identify relative importance of these parameters on biological N fixation. The 15N isotope dilution method is an appropriate technique to test the biological nitrogen fixation in the laboratory first. This useful knowledge can then be communicated to the farmers and can be tested under field conditions

  16. Organic matter and concentrated nitrogen removal by shortcut nitrification and denitrification from mature municipal landfill leachate

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-jun; PENG Yong-zhen; WANG Shu-ying; ZHENG Shu-wen; GUO Jin

    2007-01-01

    An UASB+Anoxic/Oxic (A/O) system was introduced to treat a mature landfill leachate with low carbon-to-nitrogen ratio and high ammonia concentration. To make the best use of the biodegradable COD in the leachate, the denitrification of NOx-N in the recirculation effluent from the clarifier was carried out in the UASB. The results showed that most biodegradable organic matters were removed by the denitrification in the UASB. The NH4+-N loading rate (ALR) of A/O reactor and operational temperature was 0.28-0.60 kg NH4+-N/(m3·d) and 17-29℃ during experimental period, respectively. The short-cut nitrification with nitrite accumulation efficiency of 90%-99% was stabilized during the whole experiment. The NH4+-N removal efficiency varied between 90% and 100%. When ALR was less than 0.45 kg NH4+-N/(m3·d), the NH4+-N removal efficiency was more than 98%. With the influent NH4+-N of 1200-1800 mg/L, the effluent NH4+-N was less than 15 mg/L. The shortcut nitrification and denitrification can save 40% carbon source, with a highly efficient denitrification taking place in the UASB. When the ratio of the feed COD to feed NH4+-N was only 2-3, the total inorganic nitrogen (TIN) removal efficiency attained 67%-80%. Besides, the sludge samples from A/O reactor were analyzed using FISH. The FISH analysis revealed that ammonia oxidation bacteria (AOB) accounted for 4% of the total eubacterial population, whereas nitrite oxidation bacteria (NOB) accounted only for 0.2% of the total eubacterial population.

  17. Nitrogen and carbon removal efficiency of a polyvinyl alcohol gel based moving bed biofilm reactor system.

    Science.gov (United States)

    Gani, Khalid Muzamil; Singh, Jasdeep; Singh, Nitin Kumar; Ali, Muntjeer; Rose, Vipin; Kazmi, A A

    2016-01-01

    In this study, the effectiveness of polyvinyl alcohol (PVA) gel beads in treating domestic wastewater was investigated: a moving bed biofilm reactor (MBBR) configuration (oxic-anoxic and oxic) with 10% filling fraction of biomass carriers was operated in a continuously fed regime at temperatures of 25, 20, 15 and 6 °C with hydraulic retention times (HRTs) of 32 h, 18 h, 12 h and 9 h, respectively. Influent loadings were in the range of 0.22-1.22 kg N m(-3) d(-1) (total nitrogen (TN)), 1.48-7.82 kg chemical oxygen demand (COD) m(-3) d(-1) (organic) and 0.12-0.89 kg NH4(+)-N m(-3)d(-1) (ammonia nitrogen). MBBR performance resulted in the maximum TN removal rate of 1.22 kg N m(-3) d(-1) when the temperature and HRT were 6 °C and 9 h, respectively. The carbon removal rate at this temperature and HRT was 6.82 kg COD m(-3) d(-1). Ammonium removal rates ranged from 0.13 to 0.75 kg NH4(+)-N m(-3) d(-1) during the study. Total phosphorus and suspended solid removal efficiency ranged from 84 to 98% and 85 to 94% at an influent concentration of 3.3-7.1 mg/L and 74-356 mg/L, respectively. The sludge wasted from the MBBR exhibited light weight features characterized by sludge volume index value of 185 mL/g. Experimental data obtained can be useful in further developing the concept of PVA gel based wastewater treatment systems. PMID:27054722

  18. Effects of Sludge Retention Times on Nutrient Removal and Nitrous Oxide Emission in Biological Nutrient Removal Processes

    OpenAIRE

    Bo Li; Guangxue Wu

    2014-01-01

    Sludge retention time (SRT) is an important factor affecting not only the performance of the nutrient removal and sludge characteristics, but also the production of secondary pollutants such as nitrous oxide (N2O) in biological nutrient removal (BNR) processes. Four laboratory-scale sequencing batch reactors (SBRs), namely, SBR5, SBR10, SBR20 and SBR40 with the SRT of 5 d, 10 d, 20 d and 40 d, respectively, were operated to examine effects of SRT on nutrient removal, activated sludge characte...

  19. Phycoremediation of landfill leachate with chlorophytes: Phosphate a limiting factor on ammonia nitrogen removal.

    Science.gov (United States)

    Paskuliakova, Andrea; Tonry, Steven; Touzet, Nicolas

    2016-08-01

    The potential of microalgae to bioremediate wastewater has been reported in numerous studies but has not been investigated as extensively for landfill leachate, which may be attributed to its complex nature and toxicity. In this study we explored if microalgal phycoremediation could constitute an alternative biological treatment option for landfill leachate management in regions with temperate climatic conditions. The aim of this study was to assess the performance of microalgae species at relatively low temperature (15 °C) and light intensity (14:10 h, light: dark, 22 μmol m(-2) s(-1)) for reduction in energy inputs. Four chlorophyte strains originating from the North-West of Ireland were selected and used in batch experiments in order to evaluate their ability to reduce total ammonia nitrogen, oxidised nitrogen and orthophosphate in landfill leachate. The Chlamydomonas sp. strain SW15aRL isolated from raw leachate achieved the highest level of pollutant reduction whereby a decrease of 51.7% of ammonia nitrogen was observed in 10% raw leachate (∼100 mg l(-1) NH4(+)-N) by day 24 in experiments without culture agitation. However, in the experiment conducted with 10% raw leachate supplemented with phosphate, a decrease of 90.7% of ammonia nitrogen was obtained by day 24 while also achieving higher biomass production. This series of experiments pointed to phosphorus being a limiting factor in the microalgae based phycoremediation of the landfill leachate. The effective reduction of ammonia nitrogen in landfill leachate can be achieved at lower temperature and light conditions. This was attained by employing native species adapted to such conditions and by improving nutrient balance. PMID:27161884

  20. An efficient process for wastewater treatment to mitigate free nitrous acid generation and its inhibition on biological phosphorus removal

    Science.gov (United States)

    Zhao, Jianwei; Wang, Dongbo; Li, Xiaoming; Yang, Qi; Chen, Hongbo; Zhong, Yu; An, Hongxue; Zeng, Guangming

    2015-02-01

    Free nitrous acid (FNA), which is the protonated form of nitrite and inevitably produced during biological nitrogen removal, has been demonstrated to strongly inhibit the activity of polyphosphate accumulating organisms (PAOs). Herein we reported an efficient process for wastewater treatment, i.e., the oxic/anoxic/oxic/extended-idle process to mitigate the generation of FNA and its inhibition on PAOs. The results showed that this new process enriched more PAOs which thereby achieved higher phosphorus removal efficiency than the conventional four-step (i.e., anaerobic/oxic/anoxic/oxic) biological nutrient removal process (41 +/- 7% versus 30 +/- 5% in abundance of PAOs and 97 +/- 0.73% versus 82 +/- 1.2% in efficiency of phosphorus removal). It was found that this new process increased pH value but decreased nitrite accumulation, resulting in the decreased FNA generation. Further experiments showed that the new process could alleviate the inhibition of FNA on the metabolisms of PAOs even under the same FNA concentration.

  1. A New Approach for Removal of Nitrogen Oxides from Synthetic Gas-streams under High Concentration of Oxygen in Biofilters

    Institute of Scientific and Technical Information of China (English)

    Shao Bin HUANG; Ju Guang ZHANG; He Ping HU; Yue SITU

    2005-01-01

    The potential of using denitrifying and nitrifying concurrent biofilters for the removal of nitrogen oxides from synthetic gas streams was studied under the condition of high oxygen concentration. It was found that more than 85% of nitric oxide was removed from synthetic combustion gas-streams which contained 20% oxygen and 350 μL/L NO, with a residence time of60 seconds. In the process, it was found that the existing of oxygen showed no evident negative effect on the efficiency of nitrogen removal.

  2. Struvite Precipitation for Ammonia Nitrogen Removal in 7-Aminocephalosporanic Acid Wastewater

    Directory of Open Access Journals (Sweden)

    Erhong Duan

    2012-02-01

    Full Text Available 7-Aminocephalosporanic acid wastewater usually contains high concentrations of ammonium (NH4+-N, which is known to inhibit nitrification during biological treatment processes. Chemical precipitation is a useful technology to remove ammonium from wastewater. In this paper, the removal of ammonium from 7-aminocephalosporanic acid wastewater was studied. The optimum pH, molar ratio, and various chemical compositions of magnesium ammonium phosphate (MAP precipitation were investigated. The results indicated that ammonium in 7-aminocephalosporanic acid wastewater could be removed at an optimum pH of 9. The Mg2+:NH4+-N:PO43−-P molar ratio was readily controlled at a ratio of 1:1:1.1 to both effectively remove ammonium and avoid creating a higher concentration of PO43−-P in the effluent. MgCl2·6H2O + 85% H3PO4 was the most efficient combination for NH4+-N removal. Furthermore, the lowest concentration of the residual PO43−-P was obtained with the same combination. Struvite precipitation could be considered an effective technology for the NH4+-N removal from the 7-aminocephalosporanic acid wastewater.

  3. Evaluation of Residence Time on Nitrogen Oxides Removal in Non-Thermal Plasma Reactor.

    Directory of Open Access Journals (Sweden)

    Pouyan Talebizadeh

    Full Text Available Non-thermal plasma (NTP has been introduced over the last few years as a promising after- treatment system for nitrogen oxides and particulate matter removal from diesel exhaust. NTP technology has not been commercialised as yet, due to its high rate of energy consumption. Therefore, it is important to seek out new methods to improve NTP performance. Residence time is a crucial parameter in engine exhaust emissions treatment. In this paper, different electrode shapes are analysed and the corresponding residence time and NOx removal efficiency are studied. An axisymmetric laminar model is used for obtaining residence time distribution numerically using FLUENT software. If the mean residence time in a NTP plasma reactor increases, there will be a corresponding increase in the reaction time and consequently the pollutant removal efficiency increases. Three different screw thread electrodes and a rod electrode are examined. The results show the advantage of screw thread electrodes in comparison with the rod electrode. Furthermore, between the screw thread electrodes, the electrode with the thread width of 1 mm has the highest NOx removal due to higher residence time and a greater number of micro-discharges. The results show that the residence time of the screw thread electrode with a thread width of 1 mm is 21% more than for the rod electrode.

  4. Simultaneous nitrogen and phosphor removal in an aerobic submerged membrane bioreactor

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-wei; WU Zhi-chao; GU Guo-wei; YU Guo-ping; MA Lu-ming

    2006-01-01

    Simultaneous nitrification and denitrification (SND) effect and phosphor removal were investigated in a one-staged aerobic submerged membrane bioreactor on pilot-scale with mixed liquor suspended solids (MLSS) 19-20 g/L. The effects of DO concentration, sludge floc size distribution on SND were studied. Test results suggested that SND was successfully performed in the membrane bioreactor (MBR) and about 70% total nitrogen removal efficiency was achieved when DO concentration was set to 0.2-0.3 mg/L. The main mechanisms governing SND were the suitable sludge floc size and the low DO concentration which was caused by low oxygen transfer rate with such a high MLSS concentration in the MBR. In the meantime, phosphor removal was also studied with polymer ferric sulfate (PFS) addition and 14 mg/L dosage of PFS was proper for the MBR to remove phosphor. PFS addition also benefited the MBR operation owing to its reduction of extracellular polymer substances (EPS) of mixed liquor.

  5. A novel shortcut nitrogen removal process using an algal-bacterial consortium in a photo-sequencing batch reactor (PSBR).

    Science.gov (United States)

    Wang, Meng; Yang, Han; Ergas, Sarina J; van der Steen, Peter

    2015-12-15

    Removal of nitrogen from anaerobically digested swine manure centrate was investigated in a photo-sequencing batch reactor (PSBR) with alternating light and dark periods. Microalgal photosynthesis was shown to provide enough oxygen for complete nitritation during the light period. With addition of an organic carbon source during the dark period, the reactor removed over 90% total nitrogen (TN) without aeration other than by mixing. Overall, 80% of the TN removal was through nitritation/denitritation and the rest was due to biomass uptake. The high concentrations of ammonia and nitrite and low dissolved oxygen concentration in the PSBR effectively inhibited nitrite oxidizing bacteria, resulting in stable nitritation. The hybrid microalgal photosynthesis and shortcut nitrogen removal process has the potential to substantially reduce aeration requirements for treatment of anaerobic digestion side streams. The PSBR also produced well settling biomass with sludge volume index of 62 ± 16 mL mg(-1). PMID:26378730

  6. Nitrogen removal by autotrophic ammonium oxidizing bacteria enrichment under anaerobic conditions

    Directory of Open Access Journals (Sweden)

    Pongsak (Lek Noophan

    2008-07-01

    Full Text Available Sludge from an anoxic tank at the centralized wastewater treatment plant, Nong Khaem, Bangkok, Thailand, was inoculatedin an anaerobic sequencing batch reactor (ASBR. The optimal compositions and operating conditions of the stock of autotrophic ammonium oxidizing bacteria medium were determined. The process of oxidizing ammonium with bacteria under anaerobic conditions is often referred to as the Anammox process (NO2- to N2 gas, using NH4+ as the electron donor and NO2- as the electron acceptor. The startup period for the anammox culture took more than three months. With ammoniumand nitrite concentration ratios of 1:1.38 and 1:1.6, the nitrogen conversion rate zero order. Fluorescent in situ hybridization(FISH was used to identify specific autotrophic ammonium oxidizing bacteria (Nitrosomonas spp., Candidatus Brocadia anammoxidans, and Candidatus Kuenenia stuttgartiensis. Results from this work demonstrated a shift in the species of ammonium oxidizing bacteria from Nitrosomonas spp. to Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis, with increased ammonium concentrations from 3 mM to 15 mM. Under NH4+:NO2- ratios of 1:1.38 and 1:1.6 the ammoniumoxidizing bacteria were able to remove both ammonium and nitrite simultaneously. The specific nitrogen removal rate of theanammox bacteria (Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis was significantly higher than that of anaerobic ammonium oxidizing bacteria (Nitrosomonas spp.. Anaerobic ammonium oxidizing bacteria (Candidati Brocadia anammoxidans and Kuenenia stuttgartiensis are strict anaerobes.

  7. Modeling simultaneous carbon and nitrogen removal (SCNR) in anaerobic/anoxic reactor treating domestic wastewater.

    Science.gov (United States)

    Mendes, Carlos; Esquerre, Karla; Queiroz, Luciano Matos

    2016-07-15

    This paper presents a mathematical model based on the Anaerobic Digestion Model No. 1 (ADM1) to simulate the effects of nitrate concentration and hydraulic retention time (HRT) on the simultaneous carbon and nitrogen removal (SCNR) in anaerobic/anoxic reactor treating domestic wastewater. The model was calibrated using previously published experimental data obtained from anaerobic batch tests for different COD/ [Formula: see text] ratios. Model simulations were performed to predict the SCNR in a completely mixed reactor (CSTR) operating under mesophilic conditions (35 °C). Six different scenarios were evaluated to investigate the performance of the SCNR based on typical influent characteristics of domestic wastewater. The variables analyzed were chemical oxygen demand (COD) removal, nitrate concentration, methane production, nitrogen gas, volatile fatty acids (VFA) concentration, pH and percentage of COD used by the denitrifying and methanogenic microorganisms. The HRT was decreased stepwise from 15 to 4 h. The results indicate that Scenario (S5) with a COD/ [Formula: see text] ratio equal to 10 and an HRT equal to 15 h ensures the occurrence of the stable SCNR. Furthermore, the accumulation of denitrification intermediates and a significant reduction in the biogas production when the organic matter is limited was verified. PMID:27088208

  8. Biological removal of cyanide compounds from electroplating wastewater (EPWW) by sequencing batch reactor (SBR) system

    International Nuclear Information System (INIS)

    Biological treatment system especially, sequencing batch reactor (SBR) system could not be applied to treat the raw electroplating wastewater (EPWW) due to the low organic matter concentration of 10 ± 3 mg-BOD5/L and toxic of high cyanide concentration of 23.0 ± 2.2 mg-CN/L. However, EPWW could be used as the nitrogen source for the bio-sludge of SBR system. And 10% of EPWW (the final cyanide concentration of 2.3 ± 0.2 mg/L) was most suitable to supplement into the wastewater as the nitrogen source. SBR system showed the highest COD, BOD5, TKN and cyanide removal efficiencies of 79 ± 2%, 85 ± 3%, 49.0 ± 2.1% and 97.7 ± 0.7%, respectively with 4-times diluted Thai-rice noodle wastewater (TRNWW) containing 10% EPWW and 138 mg/L NH4Cl (BOD5: TN of 100:10) at SRT of 72 ± 13 days (under organic and cyanide loadings of 0.40 kg-BOD5/m3 d and 0.0023 kg-CN/m3 d, respectively). However, the effluent ammonia was still high of 22.6 ± 0.4 mg-N/L while the effluent nitrate and nitrite was only 9.9 ± 0.4 and 1.2 ± 0.9 mg-N/L, respectively. And SVI and effluent SS of the system were higher than 95 and 75 mg/L, respectively

  9. Enhanced biological phosphorus removal - results of experiences in three large waste water treatment plants

    International Nuclear Information System (INIS)

    Within a scientific project especially the operation of four real-size sewage treatment plants with different processes of enhanced biological phosphorus removal is investigated under the aspect of efficiency, stability, practicability and costs of the enhanced biological phosphorus removal. Three plants and first results are explained and compared as well with one another as with data, which are generally regarded as favourable conditions for the enhanced biological phosphorus removal. Between the plants there are significant differences in the degree of P-elimination mainly due to different characteristics of the wastewater. An important influence on P-effluent concentrations may be exacted by P-resolution in the final clarifier. (orig.)

  10. Biological removal of methanol from process condensate for the purpose of reclamation

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-ming; YANG Min; ZHANG Yu; GAO Meng-chun; ZHANG Jing

    2004-01-01

    The biological removal of methanol from condensate of ammonia manufacturing processes for the purpose of reclamation using contact type reactor was studied. Methanol of 60 mg/L was removed completely under an HRT of 1.12 h. Optimal inorganic nutrient dose was determined on evaluating methanol removal performance and dehydrogenase activities (DHA) under different nutrition doses. The optimal inorganic nutrient dose only gave an increase of conductivity of ca. 10 μs/cm2 in the effluent on treating synthetic condensate containing methanol of 30 mg/L. The results demonstrated that biological removal of methanol was effective for the purpose of recovering the methanol-bearing condensate.

  11. Genetic Improvement of Biological Nitrogen Fixation in Common Bean Genotypes (Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Golparvar

    2012-06-01

    Full Text Available Fifty common bean genotypes were cultivated in two separately field trials at the research station of Islamic Azad University, Khorasgan Branch during 2008-2009. The experimental design was randomized complete block. Bean seeds were inoculated by Rhizobium legominosarum biovar Phaseoli isolate L-109 in one of the experiments before sowing. The dose of Rhizobium for seed inoculation was 7 miligrams of bacteria for 1 kilogram of seed. The second experiment was control. The second experiment was analyzed in the same way as the first except for biological nitrogen fixation. The results showed definite positive and significant correlation in percentage of nitrogen fixation with some other been characters. Step-wise regression designated that total nitrogen percentage in shoot, number of nodules per plant and biomass yield accounted for 93.8% of variation expect for nitrogen fixation percent. Path analysis indicated that total nitrogen percentage in shoot, number of nodules per plant and biomass yield have direct and positive effect on nitrogen fixation index. Hence, total nitrogen percentage in shoot, number of nodules per plant and biomass yield are promising indirect selection criteria for genetic improvement of nitrogen fixation capability in common bean genotypes.

  12. Removal of chemical oxygen demand, nitrogen, and heavy metals using a sequenced anaerobic-aerobic treatment of landfill leachates at 10-30 degrees C.

    Science.gov (United States)

    Kalyuzhnyi, Sergey; Gladchenko, Marina; Epov, Andrey; Appanna, Vasu

    2003-01-01

    As a first step of treatment of landfill leachates (total chemical oxygen demand [COD]: 1.43-3.81 g/L; total nitrogen: 90-162 mg/L), performance of laboratory upflow anaerobic sludge bed reactors was investigated under mesophilic (30 degrees C), submesophilic (20 degrees C), and psychrophilic (10 degrees C) conditions. Under hydraulic retention times (HRTs) of about 0.3 d, when the average organic loading rates (OLRs) were about 5 g of COD/(L.d), the total COD removal accounted for 81% (on average) with the effluent concentrations close to the anaerobic biodegradability limit (0.25 g of COD/L) for mesophilic and submesophilic regimes. The psychrophilic treatment conducted under an average HRT of 0.34 d and an average OLR of 4.22 g of COD/(L.d) showed a total COD removal of 47%, giving effluents (0.75 g of COD/L) more suitable for subsequent biologic nitrogen removal. All three anaerobic regimes used for leachate treatment were quite efficient for elimination of heavy metals (Fe, Zn, Cu, Pb, Cd) by concomitant precipitation in the form of insoluble sulfides inside the sludge bed. The application of aerobic/ anoxic biofilter as a sole polishing step for psychrophilic anaerobic effluents was acceptable for elimination of biodegradable COD and nitrogen approaching the current standards for direct discharge of treated wastewater. PMID:12794293

  13. Impact of biological filtrations for organic micropollutants and polyfluoroalkyl substances removal from secondary effluent.

    Science.gov (United States)

    Pramanik, Biplob Kumar; Pramanik, Sagor Kumar; Suja, Fatihah

    2016-08-01

    The impact of biological activated carbon (BAC), sand filtration (SF) and biological aerated filter (BAF) for removal of the selected organic micropollutants and polyfluoroalkyl substances (PFASs) from secondary effluent was studied. BAC led to greater removal of dissolved organic carbon (43%) than BAF (30%) which in turn was greater than SF (24%). All biological filtration systems could effectively remove most of the selected organic micropollutants, and there was a greater removal of these micropollutants by BAC (76-98%) than BAF (70-92%) or SF (68-90%). It was found that all treatment was effective for removal of the hydrophobic (log D > 3.2) and readily biodegradable organic micropollutants. The major mechanism for the removal of these molecules was biodegradation by the micro-organism and sorption by the biofilm. Compared to organic micropollutants removal, there was a lower removal of PFASs by all treatments, and BAF and SF had a considerably lower removal than BAC treatment. The better removal for all molecule types by BAC was due to additional adsorption capacity by the activated carbon. This study demonstrated that the BAC process was most effective in removing organic micropollutants present in the secondary effluent. PMID:26695189

  14. Pilot-scale experience with biological nutrient removal and biomass yield reduction in a liquid-solid circulating fluidized bed bioreactor.

    Science.gov (United States)

    Chowdhury, Nabin; Nakhla, George; Zhu, Jesse; Islam, Mohammad

    2010-01-01

    A pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor was developed at the Adelaide Pollution Control Plant, London, Ontario, Canada, to study its commercial viability for biological nutrient removal. Lava rock particles of 600 microm were used as a biomass carrier media. The LSCFB removed approximately 90% organic, 80% nitrogen, and 70% phosphorus at loading rates of 4.12 kg COD/m3 x d, 0.26 kg N/m3 x d, and 0.052 kg P/m3 x d, and an empty bed contact time of 1.5 hours. Effluent characterized by clarifier removed suspended solids removal without chemicals. A significant reduction (approximately 75%) in biomass yield to 0.12 to 0.16 g VSS/g chemical oxygen demand (COD) was observed, primarily because of long biological solids retention time (SRT) of 20 to 39 days and a combination of anoxic and aerobic COD consumption. PMID:20942332

  15. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Xu Gang, E-mail: xg335300@yahoo.com.cn [Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang 550025 (China); Institute of Entomology, Guizhou University, Guiyang 550025 (China); Wang Xiaoteng [Department of Agricultural Resources and Environment, College of Agricultural, Guizhou University, Guiyang 550025 (China); Gan Cailing; Fang Yanqiong; Zhang Meng [College of Life Sciences, Guizhou University, Guiyang 550025 (China)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We analyzed biological effects of N{sup +} implantation on dry Jatropha curcas seed. Black-Right-Pointing-Pointer N{sup +} implantation greatly decreased seedling survival rate. Black-Right-Pointing-Pointer At doses beyond 15 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place. Black-Right-Pointing-Pointer CAT was essential for H{sub 2}O{sub 2} removal. POD mainly functioned as seed was severely hurt. Black-Right-Pointing-Pointer HAsA-GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N{sup +} with energy of 25 keV was applied to treat the dry seed at six different doses. N{sup +} beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 Multiplication-Sign 10{sup 16} to 15 Multiplication-Sign 10{sup 16} ions cm{sup -2} severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 Multiplication-Sign 10{sup 16} ions cm{sup -2} may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  16. [Single-stage autotrophic nitrogen removal reactor with self-generated granular sludge for treating sludge dewatering effluent].

    Science.gov (United States)

    Cao, Jian-ping; Du, Bing; Liu, Yin; Qin, Yong-sheng

    2009-10-15

    Single-stage autotrophic nitrogen removal (SANR) has been observed in a long-term operated nitrosation air-lift reactor for treating digested sludge dewatering effluent from sewage wastewater treatment plant. A kind of so called self-generated granular sludge which undertake the SANR reaction has oriented formed. The performance of SANR reactor cultivated above sludge for treating sludge dewatering effluent has been tested and better results have been reached. When the influent total nitrogen (TN) was kept about 350 mg/L (mainly ammonium nitrogen), the average TN removal efficiency and nitrogen removal load were 74.8% (maximum 86.92%) and 0.68 kg x (m3 x d)(-1) [maximum 0.9 kg x (m3 x d)(-1)] respectively. The operation stability and nitrogen removal efficiency have been enforced after adding a certain quantity powered activated carbon. The influent ammonium concentration, nitrogen load and aeration rate have a great effect on SANR reactor as well as the influent organic compound, pH, alkalinity have a relatively low effect. The parameters such as the ratios of aeration rate/deltaTN, aeration rate/deltaNH4+ -N, deltaALK/deltaTN can be used for better controlling the reaction. PMID:19968119

  17. Genome reconstruction and gene expression of "Candidatus Accumulibacter phosphatis" Clade IB performing biological phosphorus removal.

    Science.gov (United States)

    Mao, Yanping; Yu, Ke; Xia, Yu; Chao, Yuanqing; Zhang, Tong

    2014-09-01

    We report the first integrated metatranscriptomic and metagenomic analysis of enhanced biological phosphorus removal (EBPR) sludge. A draft genome of Candidatus Accumulibacter spp. strain HKU-1, a member of Clade IB, was retrieved. It was estimated to be ∼90% complete and shared average nucleotide identities of 83% and 88% with the finished genome CAP IIA UW-1 and the draft genome CAP IA UW-2, respectively. Different from CAP IIA UW-1, the phosphotransferase (pap) in polyphosphate metabolism and V-ATPase in orthophosphate transport were absent from CAP IB HKU-1. Additionally, unlike CAP IA UW-2, CAP IB HKU-1 carried the genes for carbon fixation and nitrogen fixation. Despite these differences, the key genes required for acetate uptake, glycolysis and polyhydroxyalkanoate (PHA) synthesis were conserved in all these Accumulibacter genomes. The preliminary metatranscriptomic results revealed that the most significantly up-regulated genes of CAP IB HKU-1 from the anaerobic to the aerobic phase were responsible for assimilatory sulfate reduction, genetic information processing and phosphorus absorption, while the down-regulated genes were related to N2O reduction, PHA synthesis and acetyl-CoA formation. This study yielded another important Accumulibacter genome, revealed the functional difference within the Accumulibacter Type I, and uncovered the genetic responses to EBPR stimuli at a higher resolution. PMID:25089581

  18. Application of Moving Bed Biofilm Process for Biological Organics and Nutrients Removal from Municipal Wastewater

    OpenAIRE

    M. Kermani; B BINA; Haji Movahedian; Amin, M. M.; M. Nikaein

    2008-01-01

    In this study, experiments have been conducted to evaluate the organics and nutrients removal from synthetic wastewater by a laboratory scale moving bed biofilm process. For nutrients removal, moving bed biofilm process has been applied in series with anaerobic, anoxic and aerobic units in four separate reactors. Moving bed biofilm reactors were operated continuously at different loading rates of nitrogen and Phosphorus. During optimum conditions, close to complete nitrification with average ...

  19. BIOLOGICAL TREATING TECHNOLOGY TO REMOVE PHENOLS IN FCCU EFFLUENT

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Baesd on the survey in 1997 fiscal year, we have been making a further survey and study together with 中国石油(Petro China) at Liaohe Refinery since 1998 fiscal year, aiming at the transfer of Japanese waste water treating technologies to China.   Scope is as follows:   (1) Demonstration of a new waste water treating technology, a kind of biological treating methods (Fluidized bed biological treatment), to eliminate phenols in FCCU effluent.   (2) Recommendation of eliminating pollutant and reducing total effluent by improving the operation.    1 Fluidized bed biological treatment 1.1 What is fluidized bed biological treatment   Fluidized bed biological treatment is the process to treat waste water as follows:   (1) To put biologically inert granular matters (fluidized carrier) into an aeration tank;   (2) Homogeneously and entirely to fluidize the particles in the tank to form highly active biofilm on the surface of each particle;   (3) To contact organic substances with these microorganisms to purify the waste water.   The surface area of the particle per unit volume is about ten times as large as that in conventional biofilm treatment process. In addition, no blockade of the filler (carrier) may be caused. Accordingly, volumetric loading of the aeration tank can be improved to attain highly efficient treatment.

  20. Suitability of constructed wetlands and waste stabilisation ponds in wastewater treatment: nitrogen transformation and removal

    Science.gov (United States)

    Senzia, M. A.; Mashauri, D. A.; Mayo, A. W.

    It is estimated that 90% of sewage in cities in developing countries are today discharged untreated into water bodies. In Tanzania, pollution of rivers such as Karanga, Njoro and Rao in Moshi; Mirongo in Mwanza and Themi in Arusha is the cause of frequent disease outbreaks in communities downstreams. Solutions to effluent crisis can be found by its proper treatment and disposal. The principal objective of wastewater treatment is to allow effluents to be disposed without danger to human health or unacceptable damage to the ecology of receiving water bodies. Field investigations were made on pilot scale horizontal subsurface flow constructed wetlands (CW) units located downstream of waste stabilisation ponds (WSP). Six units filled with gravel of 6-25 mm diameters in equal proportion, which gave an initial hydraulic conductivity of 86 m/d were used. While four units covering surface area of 40.7 m 2 each, were located downstream of primary facultative pond, the other two units with surface area 15.9 m 2 each were located downstream of maturation pond. An attempt was made to compare the output of mathematical models for Phragmites and Typha macrophytes located downstream of primary facultative pond. Based on total inflow nitrogen of 1.457 gN/m 2 d, while Phragmites has shown a removal of 54%, Typha had a removal of 44.2%. Furthermore, while the system downstream of primary facultative pond has accretion as a major pathway, accounting for 19.1% of inflow nitrogen, the system downstream of maturation pond has denitrification as its major removal mechanism accounting for 20.5%. In this paper, a comparison of land required by CW and WSP based on the amount of water to be treated is made.

  1. Phosphorus removal and recovery from domestic wastewater in a novel process of enhanced biological phosphorus removal coupled with crystallization.

    Science.gov (United States)

    Zou, Haiming; Wang, Yan

    2016-07-01

    A new process of enhanced biological phosphorus removal coupled with crystallization recovery of phosphorus was developed here, where the feasibility of nutrients removal and potential for phosphorus recovery from domestic wastewater was further assessed. Results showed that an excellent nutrients removal and phosphorus recovery performance was achieved, in which the averaged COD, PO4(3-)-P and NO3(-)-N removal efficiencies were 82.6%, 87.5% and 91.6%, respectively and a total of 59.3% of phosphorus was recovered as hydroxyapatite. What's more, crystallization recovery of phosphorus greatly enhanced the biological phosphorus removal efficiency. After the incorporation of the phosphorus recovery column via side-stream, the phosphorus concentration of effluent was significantly decreased ranging from 1.24mg/L to 0.85mg/L, 0.52mg/L and 0.41mg/L at the lateral flow ratios of 0, 0.1, 0.2 and 0.3, respectively. The results obtained here would be beneficial to provide a prospective alternative for phosphorus removal and recovery from wastewater. PMID:27003794

  2. Evaluation of biological removal efficiency in a UCT process treating municipal wastewater during start-up stage.

    Science.gov (United States)

    Wang, Zhu; Liu, Bo; Liu, Yong-De; Wan, Fujun

    2013-04-01

    This study reports the performance of University of Cape Town (UCT) municipal wastewater treatment plant, during the startup stage with the focus on the relationship between hydraulic retention time (HRT) and biological nutrient removal (BNR) efficiency. The entire experimental period was 144 days, divided into four periods. Results showed that the removal efficiency of TN, NH4+-N, and Kjeldahl nitrogen (KN) was closely related to the HRT. Furthermore, the biodegradation kinetics analysis was used to calculate the specific degradation rates of pollutants. The GPS-X modeling was also used to examine the effect of the UCT pilot plant on BNR. The UCT pilot plant used in this study achieved high BNR efficiency even during the startup stage. With HRT of 24 hr (Period 1, day 1-40, data set 1-10), the highest levels of TN, NH(4+)-N and KN removal efficiency were approximately 72, 76 and 78%, respectively. The COD showed consistent high removal efficiency, with the highest level of approximately 96% at HRT of 15 hr (Period 3, day 81-120, data set 21-30). The TP removal efficiency rose at first and subsequently decreased abruptly. The maximum removal efficiency was 85% with HRT of 19 hr (Period 2, day 41-80, data set 11-20). With the optimal HRT 19 hr, the average removal efficiency values of COD, TP, TN, NH(4+)-N and KN were 89, 80, 65, 67 and 68%, respectively. The GPS-X modeling results indicated that the UCT process was effective in COD, TP and TN removal. PMID:24620618

  3. Influence of COD/sulfate ratios on the integrated reactor system for simultaneous removal of carbon, sulfur and nitrogen.

    Science.gov (United States)

    Yuan, Ye; Chen, Chuan; Zhao, Youkang; Wang, Aijie; Sun, Dezhi; Huang, Cong; Liang, Bin; Tan, Wenbo; Xu, Xijun; Zhou, Xu; Lee, Duu-Jung; Ren, Nanqi

    2015-01-01

    An integrated reactor system was developed for the simultaneous removal of carbon, sulfur and nitrogen from sulfate-laden wastewater and for elemental sulfur (S°) reclamation. The system mainly consisted of an expanded granular sludge bed (EGSB) for sulfate reduction and organic carbon removal (SR-CR), an EGSB for denitrifying sulfide removal (DSR), a biological aerated filter for nitrification and a sedimentation tank for sulfur reclamation. This work investigated the influence of chemical oxygen demand (COD)/sulfate ratios on the performance of the system. Influent sulfate and ammonium were fixed to the level of 600 mg SO(4)(2-) L⁻¹ and 120 mg NH(4)(+) L⁻¹, respectively. Lactate was introduced to generate COD/SO(4)(2-) = 0.5:1, 1:1, 1.5:1, 2:1, 3:1, 3.5:1 and 4:1. The experimental results indicated that sulfate could be efficiently reduced in the SR-CR unit when the COD/SO(4)(2-) ratio was between 1:1 and 3:1, and sulfate reduction was inhibited by the growth of methanogenic bacteria when the COD/SO(4)(2-) ratio was between 3.5:1 and 4:1. Meanwhile, the Org-C/S²⁻/NO(3)(-) ratios affected the S(0) reclamation efficiency in the DSR unit. When the influent COD/SO(4)(2-) ratio was between 1:1 and 3:1, appropriate Org-C/S²⁻/NO(3)(-) ratios could be achieved to obtain a maximum S° recovery in the DSR unit. For the microbial community of the SR-CR unit at different COD/SO(4)(2-) ratios, 16S rRNA gene-based high throughput Illumina MiSeq sequencing was used to analyze the diversity and potential function of the dominant species. PMID:25768217

  4. Study of nitrogen and organics removal in sequencing batch reactor (SBR) using hybrid media.

    Science.gov (United States)

    Thuan, Tran-Hung; Chung, Yun-Chul; Ahn, Dae-Hee

    2003-03-01

    The removal of nitrogen and organics in a sequencing batch reactor (SBR) using hybrid media were investigated in this work. The hybrid media was made by the use of polyurethane foam (PU) cubes and powdered activated carbon (PAC). The function of activated carbon of hybrid media was to offer a suitable active site, which was able to absorb organic substances and ammonia, as well as that of PU was to provide an appropriated surface onto which biomass could be attached and grown. A laboratory-scale moving-bed sequencing batch reactor (SBR) was used for investigating the efficiency of hybrid media. The removal of nitrogen and organics for synthetic wastewater (COD; 490-1,627 mg/L, NH4(+)-N; 180-210 mg/L) were evaluated at different COD/N ratio and different anoxic phase conditions, respectively. The system was operated with the organic loading rate (OLR) of 0.1, 0.16, 0.24, and 0.28 kg COD/m3 day, respectively. Each mode based on OLR was divided as the periods of 45 days of operation time, except for third mode that was operated during 30 days. After acclimatization period, effluent total COD concentrations slightly decreased and the removal efficiency of organics increased to about 90% (COD; 70 mg/L) after 60 days and achieved 98% (COD; 30 mg/L) at the end of experiments. The organics reduction seemed to be less affected by shock loading since high organic loads did not affect the removal efficiency. The NIH4(+)-N concentrations in effluent showed almost lower than 1 mg/L and NO3(-)-N concentrations were high (150 mg/L) during a very low C/N ratio (C/N=2). Over 90% of T-N removal efficiency (T-N; 16 mg/L) was obtained during the last 20 days of the operation after controlling the COD/N ratio (C/N=7). The mixing condition and COD/N ratio at anoxic phase were determined as a main operating factors. In future, the optimal operating conditions of SBR system with hybrid media will be investigated from the view of maintaining a sufficient biomass to the hybrid media under

  5. Effects of aeration position on organics, nitrogen and phosphorus removal in combined oxidation pond-constructed wetland systems.

    Science.gov (United States)

    Wang, Xiaoou; Tian, Yimei; Zhao, Xinhua; Peng, Sen; Wu, Qing; Yan, Lijian

    2015-12-01

    Given that few studies investigated the effects of aeration position (AP) on the performance of aerated constructed wetlands, the aim of this study was to evaluate the effects of AP on organics, nitrogen and phosphorus removal in lab-scale combined oxidation pond-constructed wetland (OP-CW) systems. Results showed that middle aeration allowed the CW to possess more uniform oxygen distribution and to achieve greater removals of COD and NH3-N, while the CW under bottom aeration and surface aeration demonstrated more distinct stratification of oxygen distribution and surface aeration brought about better TN removal capacity for the OP-CW system. However, no significant influence of artificial aeration or AP on TP removal was observed. Overall, AP could significantly affect the spatial distribution of dissolved oxygen by influencing the oxygen diffusion paths in aerated CWs, thereby influencing the removal of pollutants, especially organics and nitrogen, which offers a reference for the design of aerated CWs. PMID:26360599

  6. A new step aeration approach towards the improvement of nitrogen removal in a full scale Carrousel oxidation ditch.

    Science.gov (United States)

    Jin, Pengkang; Wang, Xianbao; Wang, Xiaochang; Ngo, Huu Hao; Jin, Xin

    2015-12-01

    Two aeration modes, step aeration and point aeration, were used in a full-scale Carrousel oxidation ditch with microporous aeration. The nitrogen removal performance and mechanism were analyzed. With the same total aeration input, both aeration modes demonstrated good nitrification outcomes with the average efficiency in removing NH4(+)-N of more than 98%. However, the average removal efficiencies for total nitrogen were 89.3% and 77.6% under step aeration and point aeration, respectively. The results indicated that an extended aerobic zone followed the aeration zones could affect the proportion of anoxic and oxic zones. The step aeration with larger anoxic zones indicated better TN removal efficiency. More importantly, step aeration provided the suitable environment for both nitrifiers and denitrifiers. The diversity and relative abundance of denitrifying bacteria under the step aeration (1.55%) was higher than that under the point aeration (1.12%), which resulted in an overall higher TN removal efficiency. PMID:26363498

  7. NITROGEN REMOVAL FROM HIGH AMMONIA PHARMACEUTICAL WASTEWATER via NITRITE%高氨氮制药废水短程生物脱氮

    Institute of Scientific and Technical Information of China (English)

    李勇智; 彭永臻; 王淑滢

    2003-01-01

    In this study, laboratory-scale experiments were conducted by using Sequencing Batch Reactor (SBR) activated sludge process to treat wastewater stream from a pharmaceutical factory. Biological nitrogen removal can be achieved via partial nitrification and denitrification and its efficiency was above 99% at 23℃±1℃. The experimental results indicated that the nitrite oxidizers were more sensitive than ammonia oxidizers to the free ammonia in wastewater. The ammonia was oxidized at pH 7 and 7.5 respectively, which suggested a critical free ammonia concentration of 0.2mg*L-1 at which the nitrite oxidizers were inhibited.

  8. Removal of Nitrogen and Pathogens in Agricultural or Urban Channles using Engineered Streambeds

    Science.gov (United States)

    McCray, J. E.; Herzog, S.; Higgins, C. P.

    2015-12-01

    Treating non-point source pollution is one of our greatest challenges in environmental hydrology. Previous efforts in agricultural or urban settings have focused on removing sources or implementing distributed best management practices (BMPs) throughout a watershed. However, for stream pollution, the most efficient point of treatment would be within the stream itself, which integrates flows from the entire watershed. Engineered streambed modifications in urban or agricultural streams and constructed channels have the potential to mitigate nonpoint source pollution. Geomedia designed to treat water pollutants and achieve an optimal residence time via hydraulic conductivity modifications are termed biohydrochemical enhancement structures for stream water treatment (BEST). BEST modules can efficiently drive interchange, attenuating nutrients and pathogens (and can be designed to remove other pollutants such as phosphorus, metals or trace organics). Numerical models, combined with data from bench-top and 2D experiments, demonstrate effective contaminant removal potential for practical applications. Nitrogen and pathogens could be attenuated within a series of BEST on the order of 50 m of stream length, and at a favorable cost compared to traditional BMPs, suggesting that BEST could be an effective best management practice for constructed stormwater channels (particularly outlets of detention ponds) or channels carrying irrigation return flows. New results from a constructed stream demonstrate the real-world applicability of the BEST system.

  9. Nitrogen and phosphorus removal from tertiary wastewater in an osmotic membrane photobioreactor.

    Science.gov (United States)

    Praveen, Prashant; Loh, Kai-Chee

    2016-04-01

    An osmotic membrane photobioreactor (OMPBR) was designed and operated for 162days for nitrogen and phosphorus removal from wastewater using Chlorella vulgaris. The removal efficiency for NH4(+)-N, NO3(-)-N and PO4(3-)-P reached as high as 95%, 53% and 89%, whereas the maximum removal rates were 3.41 mg/L-day, 0.20 mg/L-day and 0.8 mg/L-day, respectively. The microalgae exhibited high tendency to aggregate and attached to the bioreactor and membrane surfaces, and total biomass accumulation in the OMPBR was over 5 g/L. Salt accumulation and biofouling had adverse effects on membrane filtration, but the performance could be recovered through periodic backwashing of the membranes. Extracellular polymeric substances characterization indicated higher fraction of polysaccharides as compared to proteins. The biomass in the OMPBR accumulated higher levels of carbohydrates and chlorophyll. These results indicate the suitability of OMPBR in wastewater treatment and in high-density microalgae cultivation. PMID:26859325

  10. State Estimation for a Biological Phosphorus Removal Process using an Asymptotic Observer

    DEFF Research Database (Denmark)

    Larose, Claude Alain; Jørgensen, Sten Bay

    2001-01-01

    This study investigated the use of an asymptotic observer for state estimation in a continuous biological phosphorus removal process. The estimated states are the concentration of heterotrophic, autotrophic, and phosphorus accumulating organisms, polyphosphate, glycogen and PHA. The reaction scheme...

  11. Denitrification, anammox and fixed nitrogen removal in the water column of a tropical great lake

    Science.gov (United States)

    Darchambeau, François; Roland, Fleur; Crowe, Sean A.; De Brabandere, Loreto; Llirós, Marc; Garcia-Armisen, Tamara; Inceoglu, Ozgul; Michiels, Céline; Servais, Pierre; Morana, Cédric D. T.; Bouillon, Steven; Meysman, Filip; Veuger, Bart; Masilya, Pascal M.; Descy, Jean-Pierre; Borges, Alberto V.

    2013-04-01

    If rates of microbial denitrification in aquatic systems are poorly constrained, it is much more the case for tropical water bodies. Lake Kivu [2.50° S 1.59° S, 29.37° E 28.83° E] is one of the great lakes of the East African Rift. It is an oligotrophic lake characterized by anoxic deep waters rich in dissolved gases (methane and carbon dioxide) and nutrients, and by well oxygenated and nutrient-depleted surface waters. During the seasonally stratified rainy season (October to May), a nitrogenous zone characterized by the accumulation of nitrite (NO2-) and nitrate (NO3-) is often observed in the lower layer of the mixolimnion. It results from nitrification of ammonium released by decaying organic matter. With the seasonal uplift of the oxygen minimum zone, the nitrogenous zone becomes anoxic and might be the most preferential area for fixed nitrogen (N) removal in Lake Kivu. Our work aimed at identifying and quantifying the processes of N losses by denitrification and/or anammox in the nitrogenous zone of the Lake Kivu water column. During 5 sampling campaigns (March 2010, October 2010, June 2011, February 2012 and September 2012), isotopic labelling experiments were used to quantify denitrification and anammox rates along vertical profiles at two pelagic stations of the main lake. Moreover, N2:Ar ratios were estimated during the September 2012 campaign, and 16S rDNA pyrosequencing was used to describe bacterial community composition during the last 2 campaigns. No bacteria related to organisms performing anammox was observed and labelling experiments failed to detect anammox at any locations and any depths. In Lake Kivu, denitrifying bacteria were mainly related to Denitratisoma and Thiobacillus genus. Significant denitrification rates were observed at several occasions, especially under the oxic-anoxic interface in the bottom of the nitracline. The annual average denitrification rate was estimated at ~150 μmoles N m-2 d-1. Denitrification was not the only

  12. Nitrogen removal by granular nitritation-anammox in an upflow membrane-aerated biofilm reactor.

    Science.gov (United States)

    Li, Xiaojin; Sun, Shan; Badgley, Brian D; Sung, Shihwu; Zhang, Husen; He, Zhen

    2016-05-01

    The nitritation-anammox process has been a promising nitrogen removal technology towards sustainable wastewater treatment, but its application in treating domestic wastewater with relatively low ammonium concentrations (mainstream) remains a great challenge. In this study, an innovative lab-scale upflow membrane-aerated biofilm reactor (UMABR) was employed to treat a synthetic wastewater containing 70 mg N L(-1) ammonium. With a DO level at 0.6 ± 0.1 mg O2 L(-1) and HRT of 32 h, the effluent ammonium concentration was 4.8 ± 2.0 mg N L(-1). Increasing the nitrogen loading rate from 52.4 to 104.8 g N m(-3) d(-1) with stepwise decreasing HRT from 32 to 16 h resulted in an average TN removal efficiency of 81% without nitrite accumulation. The average observed NO3(-)-N (residue)/NH4(+)-N (consumed) ratio of 8% was below the "theoretical ratio" of 13% and further reduction of nitrate residue needs to be addressed. Fluorescence in situ hybridization (FISH) and high-throughput sequencing analyses showed the coexistence of anammox bacteria and ammonium-oxidizing bacteria (AOB) in both biofilm and granular samples. Anammox bacteria accounted for up to 63.3% of the microbial community of the granules, with Candidatus Jettenia being the distinctly dominant anammox genus. In contrast, the biofilm contained abundant Nitrosomonadaceae (AOB, 33.1%). In addition, the brown-yellow granules exhibited a more balanced community structure with anammox bacteria and AOB accounting for 33.7% and 18.2%, respectively, which may contribute to the long-term operation of single-stage nitritation-anammox process. These results demonstrate that the nitritation-anammox UMABR could potentially be used for nitrogen removal from mainstream in some specific regions with relatively warm temperature. PMID:26921710

  13. Micropollutant removal from municipal wastewater: from conventional treatments to advanced biological processes

    OpenAIRE

    Margot, Jonas

    2015-01-01

    Many micropollutants present in municipal wastewater, such as pharmaceuticals and pesticides, are poorly removed in conventional wastewater treatment plants (WWTPs), and may generate adverse effects on aquatic life. The objective of this thesis was to study and develop various options to improve micropollutant removal from municipal wastewaters. Various technologies were investigated, from conventional biological treatments to advanced physico-chemical and biological processes such as ozonati...

  14. Effects of dissolved oxygen on microbial community of single-stage autotrophic nitrogen removal system treating simulating mature landfill leachate.

    Science.gov (United States)

    Wen, Xin; Zhou, Jian; Wang, Jiale; Qing, Xiaoxia; He, Qiang

    2016-10-01

    The performance of four identical sequencing biofilm batch reactors (SBBR) for autotrophic nitrogen removal was investigated with 2000mg/L ammonia-containing mature landfill leachate at 30°C. The main objective of this study was to evaluate the effects of dissolved oxygen (DO) on the performance and microbial community of single-stage nitrogen removal using anammox and partial nitritation (SNAP) system. At an applied load of 0.5kgNm(-3)d(-1), average total nitrogen removal efficiency (TNRE) above 90% was long-term achieved with an optimal DO concentration of 2.7mg/L. The microelectrode-measured profiles showed the microenvironments inside the biofilms. 16S ribosomal Ribonucleic Acid (rRNA) amplicon pyrosequencing and denaturing gradient gel electrophoresis (DGGE) were used to analyze the microbial variations of different DO concentrations and different positions inside one reactor. PMID:27450126

  15. Nitrogen removal influence factors in A/O process and decision trees for nitrification/denitrification system

    Institute of Scientific and Technical Information of China (English)

    MA Yong; PENG Yong-zhen; WANG Shu-ying; WANG Xiao-lian

    2004-01-01

    In order to improve nitrogen removal in anoxic/oxic(A/O) process effectively for treating domestic wastewaters, the influence factors, DO(dissolved oxygen), nitrate recirculation, sludge recycle, SRT(solids residence time), influent COD/TN and HRT(hydraulic retention time) were studied. Results indicated that it was possible to increase nitrogen removal by using corresponding control strategies, such as, adjusting the DO set point according to effluent ammonia concentration; manipulating nitrate recirculation flow according to nitrate concentration at the end of anoxic zone. Based on the experiments results, a knowledge-based approach for supervision of the nitrogen removal problems was considered, and decision trees for diagnosing nitrification and denitrification problems were built and successfully applied to A/O process.

  16. Atrazine Removal from Aqueous Solutions using Submerged Biological Aerated Filter

    OpenAIRE

    Mohammad Ali Baghapour; Simin Nasseri; Zahra Derakhshan

    2013-01-01

    Atrazine is widely used in the agriculture as an herbicide. Due to its high mobility, Atrazine leaks into the groundwaters, surface waters, and drinking water wells. Many physical and chemical methods have been suggested for removing Atrazine from aquatic environments. However, these methods are very costly, have many performance problems, produce a lot of toxic intermediates which are very harmful and dangerous, and cannot completely mineralize Atrazine. In this study, biodegradation of Atra...

  17. Biological Removal of Phosphate Using Phosphate Solubilizing Bacterial Consortium from Synthetic Wastewater: A Laboratory Scale

    OpenAIRE

    Dipak Paul; Sankar Narayan Sinha

    2015-01-01

    Biological phosphate removal is an important process having gained worldwide attention and widely used for removing phosphorus from wastewater. The present investigation was aimed to screen the efficient phosphate solubilizing bacterial isolates and used to remove phosphate from synthetic wastewater under shaking flasks conditions. Pseudomonas sp. JPSB12, Enterobacter sp. TPSB20, Flavobacterium sp. TPSB23 and mixed bacterial consortium (Pseudomonas sp. JPSB12+Enterobacter sp. TPSB20+Flavobact...

  18. A Comparative Study of the Bacterial Community in Denitrifying and Traditional Enhanced Biological Phosphorus Removal Processes

    OpenAIRE

    Lv, Xiao-Mei; Shao, Ming-Fei; Li, Chao-Lin; Li, Ji; Gao, Xin-lei; Sun, Fei-Yun

    2014-01-01

    Denitrifying phosphorus removal is an attractive wastewater treatment process due to its reduced carbon source demand and sludge minimization potential. Two lab-scale sequencing batch reactors (SBRs) were operated in alternating anaerobic-anoxic (A-A) or anaerobic-oxic (A-O) conditions to achieve denitrifying enhanced biological phosphate removal (EBPR) and traditional EBPR. No significant differences were observed in phosphorus removal efficiencies between A-A SBR and A-O SBR, with phosphoru...

  19. Removal of nitrogen and phosphorus from wastewater in a constructed wetland system using vetiver grass

    Directory of Open Access Journals (Sweden)

    Rogério de Araújo Almeida

    2012-12-01

    Full Text Available This study aimed to evaluate the Vetiver grass (Vetiveria zizanioides L. Nash efficiency in removing nitrogen and phosphorus from the wastewater in a constructed wetlands treatment system. The experimental unit had twelve treatment modules, filled with layers of substrate. From the bottom to the surface, the following materials were placed: 0.15 m of gravel # 3; 0.10 m of gravel # 1; 0.20 m of washed sand and 0.05 m of gravel # 1. Inside the modules, the wastewater was maintained at 0.05 m or 0.25 m below the substrate surface, resulting in hydraulic retention times of 3.4 days and 1.9 days, respectively. The influent wastewater was captured in the entrance of a facultative pond, and it was applied to the surface of each treatment module, automatically, on a surface application rate of 51 L.m-2.d-1. The sewage percolated vertically in the system, in a sub-surface flow downward until it was captured in a drain pipe at the bottom of the module. The wastewater concentrations of total phosphorus and ammonium were analyzed before and after passing through the treatment modules. Evapotranspiration rates were measured and the efficiencies in removing the contaminant load were calculated. The results were submitted to F and Tukey tests, at 5% of probability. Treatment with the presence of the plant and sewage at 0.05 m from the surface had higher efficiency in the removal of nutrients reaching 90.5% of phosphorus removal and 93.9% for ammonia.

  20. Nitrogen Addition as a Result of Long-Term Root Removal Affects Soil Organic Matter Dynamics

    Science.gov (United States)

    Crow, S. E.; Lajtha, K.

    2004-12-01

    A long-term field litter manipulation site was established in a mature coniferous forest stand at the H.J. Andrews Experimental Forest, OR, USA in 1997 in order to address how detrital inputs influence soil organic matter formation and accumulation. Soils at this site are Andisols and are characterized by high carbon (C) and low nitrogen (N) contents, due largely to the legacy of woody debris and extremely low atmospheric N deposition. Detrital treatments include trenching to remove roots, doubling wood and needle litter, and removing aboveground litter. In order to determine whether five years of detrital manipulation had altered organic matter quantity and lability at this site, soil from the top 0-5 cm of the A horizon was density fractionated to separate the labile light fraction (LF) from the more recalcitrant mineral soil in the heavy fraction (HF). Both density fractions and whole soils were incubated for one year in chambers designed such that repeated measurements of soil respiration and leachate chemistry could be made. Trenching resulted in the removal of labile root inputs from root exudates and turnover of fine roots and active mycorrhizal communities as well as an increase of available N by removing plant uptake. Since 1999, soil solution chemistry from tension lysimeters has shown greater total N and dissolved organic nitrogen (DON) flux and less dissolved organic carbon (DOC) flux to stream flow in the trenched plots relative to the other detrital treatments. C/N ratio and C content of both light and heavy fractions from the trenched plots were greater than other detrital treatments. In the lab incubation, over the course of a year C mineralization from these soils was suppressed. Cumulative DOC losses and CO2 efflux both were significantly less in soils from trenched plots than in other detrital treatments including controls. After day 150 of the incubation, leachates from the HF of plots with trenched treatments had a DOC/DON ratio significantly

  1. Development of novel control strategies for single-stage autotrophic nitrogen removal: A process oriented approach

    DEFF Research Database (Denmark)

    Vangsgaard, Anna Katrine; Mauricio Iglesias, Miguel; Gernaey, Krist;

    2014-01-01

    The autotrophic nitrogen removing granular sludge process is a novel and intensified process. However, its stable operation and control remain a challenging issue. In this contribution, a process oriented approach was used to develop, evaluate and benchmark novel control strategies to ensure stable...... operation and rejection of disturbances. Three novel control strategies were developed, evaluated, and benchmarked against each other: a feedforward control (control structure 1 – CS#1), a rule-based feedback control (CS#2), and a feedforward–feedback controller, in which the feedback loop updates the set...... satisfactorily. Thus, the appropriate design will depend on the specific disturbances in the influent generated in the upstream units of the wastewater treatment plant....

  2. Autotrophic nitrogen removal in one lab-scale vertical submerged biofilm reactor

    Science.gov (United States)

    Liang, Zhiwei; Chen, Yingxu; Li, Wenhong; Yang, Shangyuan; Du, Ping

    In this study, the process performance of a new vertical submerged biofilm reactor for complete autotrophic ammonia removal was investigated using synthetic wastewater. The main objectives of this study were to evaluate the flexibility of the reactor, achieve partial autotrophic nitrification with influent ammonium nitrogen ranging from 40 to 280 mg L -1, and achieve a stable half partial autotrophic nitrification by controlling hydraulic retention time (HRT) and alkalinity. A very low concentration of nitrate was observed in the effluent during nitrification. Then autotrophic denitrification revealed Anammox bacteria were present and active in the central anaerobic parts of the bioreactor which was inoculated with a mixed microbial consortium from activated sludge. The results of this study demonstrated that autotrophic denitrification processes can coexist with heterotrophic denitrifying processes in the same environment even if Anammox bacteria were less competitive than heterotrophic denitrifying bacteria.

  3. Influence of Calcination on the Physical Characteristics and Nitrogen Removal Performance of Clinoptilolites

    Institute of Scientific and Technical Information of China (English)

    LIN Hai; JIN Xin; DONG Yingbo; HUO Hanxin; LIU Quanli

    2014-01-01

    The influences of roasting activation on the particle morphology, microscopic structure, and adsorption properties of natural clinoptilolites were investigated. The experimental results show that the optimal modified conditions include a calcination temperature at 400℃, a roasting time of 0.5 h, and furnace cooling. The ammonia nitrogen removal rate from analog renewable water of the modified clinoptilolites reached 72%in the optimized conditions, which is 12%higher than that of natural ones. Scanning electron microscopy analysis showed that the surface morphology changed, the micro-hole size increased, and the surface became smoother and more uniform after calcination. The single-point total adsorption average pore width increased from 7.74 nm to 10.64 nm.

  4. Sequentially aerated membrane biofilm reactors for autotrophic nitrogen removal: microbial community composition and dynamics

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Franck, Stephanie; Gülay, Arda;

    2014-01-01

    (rich in oxygen) and AnAOB in regions neighbouring the liquid phase. Both communities were separated by a transition region potentially populated by denitrifying heterotrophic bacteria. AOB and AnAOB bacterial groups were more abundant and diverse than NOB, and dominated by the r...... reduction of the NOB Nitrospira and Nitrobacter and a 10-fold increase in AnAOB numbers. The study of biofilm sections with relevant 16S rRNA fluorescent probes revealed strongly stratified biofilm structures fostering aerobic ammonium oxidizing bacteria (AOB) in biofilm areas close to the membrane surface......-strategists Nitrosomonas europaea and Ca. Brocadia anammoxidans, respectively. Taken together, the present work presents tools to better engineer, monitor and control the microbial communities that support robust, sustainable and efficient nitrogen removal....

  5. Isolation of aluminum-tolerant bacteria capable of nitrogen removal in activated sludge.

    Science.gov (United States)

    Ji, Bin; Chen, Wei; Zhu, Lei; Yang, Kai

    2016-05-15

    Four strains of bacteria capable of withstanding 20mM concentration of aluminum were isolated from activated sludge in a bioreactor. 16S rRNA identification and morphological characteristics indicated that these strains were Chryseobacterium sp. B1, Brevundimonas diminuta B3, Hydrogenophaga sp. B4, and Bacillus cereus B5. Phylogenetic analysis revealed the position and interrelationships of these bacteria. B. diminuta B3 and Hydrogenophaga sp. B4 could achieve nitrate nitrogen removal of 94.0% and 76.8% within 36h of its initial concentration of 148.8 and 151.7mg/L, respectively. Meanwhile, B3 and B4 could degrade ammonia with little nitrite accumulation. Results of this study provide more information about aluminum-resistant bacteria and laid the foundation for aluminum salt when it is simultaneously used for chemical precipitation. PMID:27038879

  6. Application of Moving Bed Biofilm Process for Biological Organics and Nutrients Removal from Municipal Wastewater

    Directory of Open Access Journals (Sweden)

    M. Kermani

    2008-01-01

    Full Text Available In this study, experiments have been conducted to evaluate the organics and nutrients removal from synthetic wastewater by a laboratory scale moving bed biofilm process. For nutrients removal, moving bed biofilm process has been applied in series with anaerobic, anoxic and aerobic units in four separate reactors. Moving bed biofilm reactors were operated continuously at different loading rates of nitrogen and Phosphorus. During optimum conditions, close to complete nitrification with average ammonium removal efficiency of 99.72% occurred in the aerobic reactor. In the aerobic reactor, the average specific nitrification rate was 1.8 g NOx-N kg VSS-1 h-1. The results of the average effluent soluble COD concentration from each reactor showed that denitrification process in the second anoxic reactor consumed most of the biodegradable organic matter. As seen from the results, denitrification rate has increased with increasing NOx-N loading in the second anoxic reactor. The aerobic phosphate removal rate showed a good correlation to the anaerobic phosphate release rate. Moreover, phosphate removal rate showed a strong correlation to the phosphate loading rate in the aerobic reactor. In optimum conditions, the average SCOD, total nitrogen and phosphorus removal efficiencies were 96.9, 84.6 and 95.8%, respectively. This study showed that the moving bed biofilm process could be used as an ideal and efficient option for the total nutrient removal from municipal wastewater.

  7. Root stimulated nitrogen removal: only a local effect or important for water treatment?

    Science.gov (United States)

    Münch, Ch; Kuschk, P; Röske, I

    2005-01-01

    Plants in constructed wetlands serve as carriers for attached microbial growth. They mainly transfer oxygen and release exsudates to the root zone. In consequence of this an area around the roots, called the rhizosphere exists, in which bacteria are stimulated by root growth. The goals were to ascertain whether stimulating the microbial cenosis only has a local effect on the rhizoplane, and to establish the importance of this stimulation for the water purification process in the root zone. Observations were carried out in a laboratory batch reactor filled with sand and planted with reeds (Phragmites australis). A small section was separated with gauze to avoid root growth outside this zone. The reactor was incubated with an artificial waste water containing a high concentration of ammonium. Samples were taken at intervals of 10 mm away from the gauze. The chemical and physical conditions and enzyme activities in soil sections at different distances from the roots affecting the efficiency of nitrogen removal were characterized. An influence was detectable by several parameters up to a specific root distance. Indirect parameters such as the total bacterial number and the DNA amount seem to be affected up to a distance of 50 mm from the root whereas the oxygen amount and DOC are unaffected at a distance exceeding 20-30 mm. This is an initial indication that improved nitrogen removal is also possible in the wider root surroundings. In view of the average root-to-root distance of 35 mm, the root-influenced area could therefore be expanded to the whole rooted zone in a constructed wetland. The influence on bacteria by roots is not just a local effect but may also play an important role in the whole purification process. PMID:16042258

  8. A wooded riparian strip set up for nitrogen removal can affect the water flux microbial composition

    Directory of Open Access Journals (Sweden)

    Mizanur Md. Rahman

    2014-02-01

    Full Text Available This research is part of a project aimed at verifying the potential of a specifically assessed wooded riparian zone in removing excess of combined nitrogen from the Zero river flow for the reduction of nutrient input into Venice Lagoon. Specific objectives were pursued to determine seasonal fluctuations of the microbial populations from the input water to a drainage ditch, conveying back the flux into the river after passing through the soil of the wooded riparian strip. The bacterial communities were determined by combined approaches involving cultivation, microscopic methods and DNA based techniques to determine both culturable and total microbial community in water. The results indicate that the size of the bacterial population, including the culturable fraction, increases from the river to the drainage ditch especially on the warm season. The multiple approach here adopted enabled also to demonstrate that the special condition created in the buffer strip supports the development and the metabolism of the microbial community. The nature of the bacterial population, in terms of phylotypes distribution, was investigated by 16S rDNA analysis indicating that the most represented genera belong to Gamma-proteobacteria, which is known to include an exceeding number of important pathogens. In spring, the effect of the buffer strip seems to significantly reduce such a sub-population. The changes observed for the total bacterial community composition become much evident in summer, as revealed by both denaturing gradient gel electrophoresis cluster analysis and by the diversity index calculation. The hydraulic management coupled to the suspension of farming practices and the development of the woody and herbaceous vegetation resulted in a condition suitable for the containment of undesired microbiota (mainly during the spring season while continuing to support denitrification activity (especially throughout the summer as verified by the total nitrogen

  9. Ammonia-nitrogen removal from urban drainage using modified fresh empty fruit bunches: A case study in Kota Kinabalu, Sabah

    Science.gov (United States)

    Ricky, L. N. S.; Shahril, Y.; Nurmin, B.; Zahrim, AY

    2016-06-01

    Highly concentration of ammonia nitrogen in urban drainage could pollute the river and give pungent smell. The strong pungent odours that coming out from the urban drainage may degrade the image a city and could possibly reduce the present of tourist. To minimize the presence of pungent odours, the ammonia nitrogen can be removed from the urban drainage by applying proper adsorbent. In this study, an adsorbent produced through chemical modification of fresh empty fruit bunch (EFB) fibers has been carried out. The maximum adsorption capacity is between 0.01-0.60 mg/g. The finding also shows that the retention time is vital when designing ammonia nitrogen filter.

  10. Study of control strategy and simulation in anoxic-oxic nitrogen removal process

    Institute of Scientific and Technical Information of China (English)

    PENG Yong-zhen; WANG Zhi-hui; WANG Shu-ying

    2005-01-01

    The control strategy and simulation of external carbon addition were specially studied in an anoxic-oxic(A/O) process with low carbon: nitrogen(C/N) domestic wastewater. The control strategy aimed to adjust the flow rate of external carbon dosage to the anoxic zone, thus the concentration of nitrate plus nitrite( NOx -N) in the anoxic zone was kept closed to the set point. The relationship was studied between the NOx-N concentration in the anoxic zone(SNo) and the dosage of external carbon, and the results showed that the removal efficiency of the total nitrogen(TN) could not be largely improved by double dosage of carbon source when SNO reached about 2mg/L. Through keeping SNO at the level of about 2 mg/L, the demand of effluent quality could be met and the carbon dosage could be optimized. Based on the Activated Sludge Model No. 1 (ASM No. 1 ), a simplified mathematical model of external carbon dosage was developed. Simulation results showed that PI controller and feed-forward PI controller both had good dynamic response and steady precision. And feed-forward PI controller had better control effects due to its consideration of influent disturbances.

  11. Identification of a novel group of bacteria in sludge from a deteriorated biological phosphorus removal reactor

    DEFF Research Database (Denmark)

    Nielsen, Alex Toftgaard; Liu, Wen-Tso; Filipe, Carlos; Grady, Leslie; Molin, Søren; Stahl, David A.

    1999-01-01

    The microbial diversity of a deteriorated biological phosphorus removal reactor was investigated by methods not requiring direct cultivation. The reactor was fed with media containing acetate and high levels of phosphate (P/C weight ratio, 8:100) but failed to completely remove phosphate in the...... effluent and showed very limited biological phosphorus removal activity. Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA was used to investigate the bacterial diversity. Up to 11 DGGE bands representing at least 11 different sequence types were observed; DNA from the 6...

  12. Identification of a novel group of bacteria in sludge from a deteriorated biological phosphorus removal reactor

    DEFF Research Database (Denmark)

    Nielsen, Alex Toftgaard; Liu, Wen-Tso; Filipe, Carlos;

    1999-01-01

    The microbial diversity of a deteriorated biological phosphorus removal reactor was investigated by methods not requiring direct cultivation. The reactor was fed with media containing acetate and high levels of phosphate (P/C weight ratio, 8:100) but failed to completely remove phosphate...... in the effluent and showed very limited biological phosphorus removal activity. Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA was used to investigate the bacterial diversity. Up to 11 DGGE bands representing at least 11 different sequence types were observed; DNA from the 6...

  13. A comparison of simultaneous organic carbon and nitrogen removal in microbial fuel cells and microbial electrolysis cells.

    Science.gov (United States)

    Hussain, Abid; Manuel, Michelle; Tartakovsky, Boris

    2016-05-15

    This study demonstrates simultaneous carbon and nitrogen removal in laboratory-scale continuous flow microbial fuel cell (MFC) and microbial electrolysis cell (MEC) and provides side-by side comparison of these bioelectrochemical systems. The maximum organic carbon removal rates in MFC and MEC tests were similar at 5.1 g L(-1) d(-1) and 4.16 g L(-1) d(-1), respectively, with a near 100% carbon removal efficiency at an organic load of 3.3 g L(-1) d(-1). An ammonium removal efficiency of 30-55% with near-zero nitrite and nitrate concentrations was observed in the MFC operated at an optimal external resistance, while open-circuit MFC operation resulted in a reduced carbon and ammonium removal of 53% and 21%, respectively. In the MEC ammonium removal was limited to 7-12% under anaerobic conditions, while micro-aerobic conditions increased the removal efficiency to 31%. Also, at zero applied voltage both carbon and ammonium removal efficiencies were reduced to 42% and 4%, respectively. Based on the observed performance under different operating conditions, it was concluded that simultaneous carbon and nitrogen removal was facilitated by concurrent anaerobic and aerobic biotransformation pathways at the anode and cathode, which balanced bioelectrochemical nitrification and denitrification reactions. PMID:26950500

  14. Biological nutrient removal from municipal wastewater in sequencing batch biofilm reactors

    Energy Technology Data Exchange (ETDEWEB)

    Arnz, P.

    2001-07-01

    Enhanced biological phosphorus removal (EBPR) has only been put into practice in activated sludge systems. In recent years, the Sequencing Batch Biofilm Reactor (SBBR) has emerged as an alternative allowing EBPR to be achieved in a biofilm reactor. High efficiency of phosphate removal was demonstrated in a SBBR fed with synthetic wastewater containing acetate. The aim of this study was to investigate EBPR from municipal wastewater in semi full-scale and laboratory-scale SBBRs. The focus of the investigation in the semi full-scale reactor was on determination of achievable reaction rates and effluent concentrations under varying influent conditions throughout all seasons of a year. Interactions between nitrogen and phosphorus removal and the influence of backwashing on the reactor performance was examined. Summing up, it can be stated that the SBBR proved to be an attractive alternative to activated sludge systems. Phosphorus elimination efficiency was comparable to common systems but biomass sedimentation problems were avoided. In order to further exploit the potential of the SBBR and to achieve reactor performances superior to those of existing systems designing a special biofilm carrier material may allow to increase the phenomenon of simultaneous nitrification/denitrification while maintaining EBPR activity. (orig.) [German] Die vermehrte biologische Phosphorelimination (Bio-P) aus Abwasser wurde bisher nur in Belebtschlammsystemen praktiziert. In den letzten Jahren konnte jedoch gezeigt werden, dass sich durch die Anwendung des Sequencing Batch Biofilm Reactor (SBBR) - Verfahrens auch in Biofilmreaktoren Bio-P verwirklichen laesst. Versuche in Laboranlagen haben ergeben, dass sich eine weitgehende Phosphorelimination aufrecht erhalten laesst, wenn die Reaktoren mit einem ideal zusammengesetzten, synthetischen Abwasser beschickt werden. Ziel dieser Arbeit war es, Bio-P aus kommunalem Abwasser in SBBR-Versuchsanlagen im halbtechnischen und im Labormassstab zu

  15. Performance of organics and nitrogen removal in subsurface wastewater infiltration systems by intermittent aeration and shunt distributing wastewater.

    Science.gov (United States)

    Pan, Jing; Yuan, Fang; Yu, Long; Huang, Linli; Fei, Hexin; Cheng, Fan; Zhang, Qi

    2016-07-01

    Organics and nitrogen removal in four subsurface wastewater infiltration systems (SWISs), named SWIS A (without intermittent aeration and shunt distributing wastewater), SWIS B (with intermittent aeration), SWIS C (with shunt distributing wastewater) and SWIS D (with intermittent aeration and shunt distributing wastewater) was investigated. High average removal rates of 92.3% for COD, 90.2% for NH4-N and 88.1% for TN were achieved simultaneously in SWIS D compared with SWIS A, B and C. The excellent TN removal of SWIS D was due to intermittent aeration provided sufficient oxygen for nitrification in upper matrix and the favorable anoxic or anaerobic environment for denitrification in subsequent matrix, and moreover, shunt distributing wastewater provided sufficient carbon source for denitrification process. The results indicated that intermittent artificial aeration combined with shunt distributing wastewater could achieve high organics and nitrogen removal in SWISs. PMID:27039353

  16. Dimensioning of a plant for enhanced biological phosphorous removal by estimation of partial steps. Berechnungsansatz fuer die biologische Phosphorelimination durch Bewertung prozessbestimmender Teilschritte

    Energy Technology Data Exchange (ETDEWEB)

    Roeske, I.; Schoenborn, C. (Technische Univ. Dresden (Germany))

    1992-05-01

    For the design of wastewater treatment plants with enhanced biological phosphorus removal and simultaneous removal of nitrogen a calculation model is proposed. The model derived from long-term investigations on bench scale plants. The key variables of the P-elimination process can be described by statistically confident equations. The calculation model can be well handled by engineers and designers. The model includes only a small number of variables, which can be measured in routine analysis. Two versions of the model are described in detail. The calculation model has been verified with independent data from five full-scale wastewater treatment plants in Germany. (orig.).

  17. Effect of carbon to nitrogen (C:N) ratio on nitrogen removal from shrimp production waste water using sequencing batch reactor.

    Science.gov (United States)

    Roy, Dhiriti; Hassan, Komi; Boopathy, Raj

    2010-10-01

    The United States Marine Shrimp Farming Program (USMSFP) introduced a new technology for shrimp farming called recirculating raceway system. This is a zero-water exchange system capable of producing high-density shrimp yields. However, this system produces wastewater characterized by high levels of ammonia, nitrite, and nitrate due to 40% protein diet for the shrimp at a high density of 1,000 shrimp per square meter. The high concentrations of nitrate and nitrite (greater than 25 ppm) are toxic to shrimp and cause high mortality. So treatment of this wastewater is imperative in order to make shrimp farming viable. One simple method of treating high-nitrogen wastewater is the use of a sequencing batch reactor (SBR). An SBR is a variation of the activated sludge process, which accomplishes many treatment events in a single reactor. Removal of ammonia and nitrate involved nitrification and denitrification reactions by operating the SBR aerobically and anaerobically in sequence. Initial SBR operation successfully removed ammonia, but nitrate concentrations were too high because of carbon limitation in the shrimp production wastewater. An optimization study revealed the optimum carbon to nitrogen (C:N) ratio of 10:1 for successful removal of all nitrogen species from the wastewater. The SBR operated with a C:N ratio of 10:1 with the addition of molasses as carbon source successfully removed 99% of ammonia, nitrate, and nitrite from the shrimp aquaculture wastewater within 9 days of operation. PMID:20835881

  18. Comparison of biological and chemical phosphorus removals in continuous and sequencing batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ketchum, L.H.; Irvine, R.L. Jr.; Breyfogle, R.E.; Manning, J.F. Jr.

    1987-01-01

    A full-scale study of phosphorus removal has been conducted at Culver using continuous-flow operation, SBR operation, and several different chemical treatment schemes. A full-scale demonstration of SBR biological phosphorus removal also has been shown to be effective. Four contributing groups of organisms and their roles in biological SBR phosphorus removal have been described: denitrifying organisms, fermentation product-manufacturing organisms, phosphorus- accumulating organisms, and aerobic autotrophs and heterotrophs. The SBR can provide the proper balance of anoxic, anaerobic, and aerobic conditions to allow these group of organisms to successfully remove phosphorus biologically, without chemical addition. Treatment results using various chemicals for phosphorus removal, both during conventional, continuous-flow operation and after the plant was converted for SBR operation, have also been provided for comparison. Effluent phosphorus concentrations were almost identical for each period, except for the period when phosphorus was removed biologically and without any chemical addition when effluent phosphorus concentrations were the lowest. These removals were made as a result of settling alone; no tertiary rapid stand filter was used or required.

  19. Biological invasion by Myrica faya in Hawaii: Plant demography, nitrogen fixation, ecosystem effects

    International Nuclear Information System (INIS)

    Myrica faya, an introduced actinorhizal nitrogen fixer, in invading young volcanic sites in Hawaii Volcanoes National Park. We examined the population biology of the invader and ecosystem-level consequences of its invasion in open-canopied forests resulting from volcanic cinder-fall. Although Myrica faya is nominally dioecious, both males and females produce large amounts of fruit that are utilized by a number of exotic and native birds, particularly the exotic Zosterops japonica. In areas of active colonization, Myrica seed rain under perch trees of the dominant native Metrosideros polymorpha ranged from 6 to 60 seeds m-2 yr-1; no seeds were captured in the open. Planted seeds of Myrica also germinated an established better under isolated individuals of Metrosideros than in the open. Diameter growth of Myrica is > 15-fold greater than that of Metrosideros, and the Myrica population is increasing rapidly. Rates of nitrogen fixation were measured using the acetylene reduction assay calibrated with 15N. Myrica nodules reduced acetylene at between 5 and 20 μmol g-1 h-1, a rate that extrapolated to nitrogen fixation of 18 kg ha-1 in a densely colonized site. By comparison, all native sources of nitrogen fixation summed to 0.2 kg ha-1 yr-1, and precipitation added -1 yr-1. Measurements of litter decomposition and nitrogen release, soil nitrogen mineralization, and plant growth in bioassays all demonstrated that nitrogen fixed by Myrica becomes available to other organisms as well. We conclude that biological invasion by Myrica faya alters ecosystem-level properties in this young volcanic area; at least in this case, the demography and physiology of one species controls characteristics of a whole ecosystem

  20. Effects of additional fermented food wastes on nitrogen removal enhancement and sludge characteristics in a sequential batch reactor for wastewater treatment.

    Science.gov (United States)

    Zhang, Yongmei; Wang, Xiaochang C; Cheng, Zhe; Li, Yuyou; Tang, Jialing

    2016-07-01

    In order to enhance nitrogen removal from domestic wastewater with a carbon/nitrogen (C/N) ratio as low as 2.2:1, external carbon source was prepared by short-term fermentation of food wastes and its effect was evaluated by experiments using sequencing batch reactors (SBRs). The addition of fermented food wastes, with carbohydrate (42.8 %) and organic acids (24.6 %) as the main organic carbon components, could enhance the total nitrogen (TN) removal by about 25 % in contrast to the 20 % brought about by the addition of sodium acetate when the C/N ratio was equally adjusted to 6.6:1. The fermented food waste addition resulted in more efficient denitrification in the first anoxic stage of the SBR operation cycle than sodium acetate. In order to characterize the metabolic potential of microorganisms by utilizing different carbon sources, Biolog-ECO tests were conducted with activated sludge samples from the SBRs. As a result, in comparison with sodium acetate, the sludge sample by fermented food waste addition showed a greater average well color development (AWCD590), better utilization level of common carbon sources, and higher microbial diversity indexes. As a multi-organic mixture, fermented food wastes seem to be superior over mono-organic chemicals as an external carbon source. PMID:26988362

  1. Membrane biofilm reactors for nitrogen removal: state-of-the-art and research needs.

    Science.gov (United States)

    Hwang, Jong Hyuk; Cicek, Nazim; Oleszkiewicz, Jan A

    2009-01-01

    Historical developments up-to-date and operational challenges of membrane biofilm reactor (MBfR) were reviewed. A database of international, peer-reviewed journal articles regarding MBfR research from 1984 to 2008 was established and analyzed with a total of 107 papers. MBfR studies began to evolve in the early 1980s, since then the number of published papers increased steadily. After 2000, geographic locations where the research was conducted widened beyond North America and Europe to Asia. Research studies were divided into 4 categories and reviewed according to their main research focuses. In spite of the short history of MBfRs, studies have shown promising potential, possibly extending their application beyond nitrogen removal and organics removal. The MBfR research branched out to new fields including autotrophic denitrification. There are some important aspects of MBfRs that pose significant challenges to the application of this technology on a commercial scale in the near-future. The main challenge revolves around biofilm thickness and activity control. Further laboratory and demonstration scale studies on some of the proposed strategies for biofilm control are needed. Ultimately, more field studies with real wastewater should be performed to evaluate the resilience of the process in the face of flow and strength fluctuations, establishing optimum operational strategies. PMID:19934494

  2. Mechanism studies on nitrogen removal when treating ammonium-rich leachate by sequencing batch biofilm reactor

    Institute of Scientific and Technical Information of China (English)

    XU Zhengyong; YANG Zhaohui; ZENG Guangming; XIAO Yong; DENG Jiuhua

    2007-01-01

    The nitrogen removal mechanism was studied and analyzed when treating the ammonium-rich landfill leachate by a set of sequencing batch biofilm reactors(SBBRs),which was designed independently.At the liquid temperature of(32±0.4)℃,and after a 58-days domestication period and a 33-days stabilization period.the efficiency of ammonium removal in the SBBR went up to 95%.Highly frequent intermittent aeration suppressed the activity of nitratebacteria.and also eliminated the influence on the activity of anaerobic ammonium oxidation(ANAMMOX)bacteria and nitritebacteria.This influence was caused by the accumulation of nitrous acid and the undulation of pH.During the aeration stage,the concentration of dissolved oxygen was controlled at 1.2-1.4 mg/L.The nitritebacteria became dominant and nitrite accumulated gradually.During the anoxic stage,along with the concentration debasement of the dissolved oxygen,ANAMMOX bacteria became dominant;then,the nitrite that was accumulated in the aeration stage was wiped off with ammonium simultaneously.

  3. Biological nitrogen fixation by lucerne (Medicago sativa L.) in acid soils.

    OpenAIRE

    Pijnenborg, J.W.M.

    1990-01-01

    Growth of lucerne( Medicago sativa L.) is poor in soils with values of pH-H2O below 6. This is often due to nitrogen deficiency, resulting from a hampered performance of the symbiosis withRhizobium meliloti. This thesis deals with the factors affecting biological nitrogen fixation by lucerne in acid soils.In a field experiment, lucerne seeds were either inoculated withR.meliloti only,or inoculated and pelleted with lime, before sowing in a sandy soil of pH 5.2. Lime-pelleting significantly im...

  4. Biological removal of metal ions from aqueous process streams

    International Nuclear Information System (INIS)

    Aqueous waste streams from nuclear fuel processing operations may contain trace quantities of heavy metals such as uranium. Conventional chemical and physical treatment may be ineffective or very expensive when uranium concentrations in the range of 10 to 100 g/m3 must be reduced to 1 g/m3 or less. The ability of some microorganisms to adsorb or complex dissolved heavy metals offers an alternative treatment method. Uranium uptake by Saccharomyces cerevisiae NRRL Y-2574 and a strain of Pseudomonas aeruginosa was examined to identify factors which might affect a process for the removal of uranium from wastewater streams. At uranium concentrations in the range of 10 to 500 g/m3, where the binding capacity of the biomass was not exceeded, temperature, pH, and initial uranium concentration were found to influence the rate of uranium uptake, but not the soluble uranium concentration at equilibrium. 6 figs

  5. Modeling organic matter and nitrogen removal from domestic wastewater in a pilot-scale vertical subsurface flow constructed wetland.

    Science.gov (United States)

    Bustillo-Lecompte, Ciro Fernando; Mehrvar, Mehrab; Quiñones-Bolaños, Edgar; Castro-Faccetti, Claudia Fernanda

    2016-01-01

    Constructed wetlands have become an attractive alternative for wastewater treatment. However, there is not a globally accepted mathematical model to predict their performance. In this study, the VS2DTI software was used to predict the effluent biochemical oxygen demand (BOD) and total nitrogen (TN) in a pilot-scale vertical flow constructed wetland (VFCW) treating domestic wastewater. After a 5-week adaptation period, the pilot system was monitored for another 6 weeks. Experiments were conducted at hydraulic retention times (HRTs) in the range of 2-4 days with Typha latifolia as the vegetation. The raw wastewater concentrations ranged between 144-430 and 122-283 mg L(-1) for BOD5 and TN, respectively. A first-order kinetic model coupled with the advection/dispersion and Richards' equations was proposed to predict the removal rates of BOD5 and TN from domestic wastewater. Two main physical processes were modeled in this study, porous material water flow and solute transport through the different layers of the VFCW to simulate the constructed wetland (CW) conditions. The model was calibrated based on the BOD5 and TN degradation constants. The model indicated that most of BOD and TN (88 and 92%, respectively) were removed through biological activity followed by adsorption. It was also observed that the evapotranspiration was seen to have a smaller impact. An additional data series of effluent BOD and TN was used for model validation. The residual analysis of the calibrated model showed a relatively random pattern, indicating a decent fit. Thus, the VS2DTI was found to be a useful tool for CW simulation. PMID:26818608

  6. Biological nitrogen fixation by faba bean, pea and vetch, using isotopic techniques (N-15) and two reference crops

    International Nuclear Information System (INIS)

    A field experiment was carried out on a Typic Dystrandept soil at Santa Catalina Experimental Station, Cutuglagua, Pichincha, Ecuador. The objectives were to quantify faba bean (Vicia faba) pea (Pisum sativum) and vetch (Vicia sativa) biological nitrogen fixation using N-15 isotopic technique and to evaluate suitability of reference crops for such quantification. Higher values of biological nitrogen fixation were obtained using maize (Zea mays L.) than using wheat (Triticum vurgare) as reference crops. The average values were 85 and 81 per cent for vetch; 73 and 69 per cent for faba bean; and 34 and 18 per cent for pea, respectively. It was assumed that nitrogen use efficiency should be the same for fixing and no fixing crop, but it was observed that a reference crop with low nitrogen use efficiency underestimates legume biological nitrogen fixation. Results suggest that greater caution is needed when selecting reference crops for legumes with low nitrogen fixation

  7. Assessment of nitrogen and sulphur cycle bacteria and shrimp production in ponds treated with biological products

    Institute of Scientific and Technical Information of China (English)

    Thangapalam Jawahar Abraham; Shubhadeep Ghosh; Debasis Sasmal

    2015-01-01

    Objective:To study the influence of biological products on the levels of nitrogen and sulphur cycle bacteria in shrimp culture systems of West Bengal, India. Methods: The pond water and sediment samples were analyzed for physico-chemical parameters as per standard methods. The bacteria involved in ammonification, nitrification, denitrification, sulphate reduction and sulphur oxidation were enumerated by most probable number technique. Results:The semi-intensive and modified extensive shrimp farms used a variety of biological products during various stages of production. No biological products were used in traditional farms. The water and sediment samples of modified extensive system recorded significantly higher mean heterotrophic bacterial counts. The counts of ammonia, nitrite and sulphur oxidizers, and nitrate and sulphate reducers varied among the systems. The cycling of nitrogen and sulphur appeared to be affected with the intensification of culture practices. Conclusions:The application of biological products in certain systems helped to maintain the bacteria involved in nitrogen and sulphur cycles and safe levels of ammonia, nitrite and nitrate. An assessment of these metabolically active bacteria in shrimp culture ponds and the application of right kind microbial products would help ameliorate the organic pollution in shrimp aquaculture.

  8. Process of nitrogen transformation and microbial community structure in the Fe(0)-carbon-based bio-carrier filled in biological aerated filter.

    Science.gov (United States)

    Deng, Shihai; Li, Desheng; Yang, Xue; Zhu, Shanbin; Li, Jinlong

    2016-04-01

    Nitrogen pollutants in low-organic carbon wastewater are difficult to biodegrade. Therefore, the Fe(0)-carbon-based bio-carrier (FCBC) was firstly used as hydrogen producer in a biological-aerated filter (BAF) to make up for the lack of organic carbon in biological nitrogen removal. Physical and chemical properties of FCBC were detected and compared in this study. The nitrogen removal rate for low COD/TN ratio wastewater, nitrogen transformation process, and microbial communities in the FCBC filled in BAF were investigated. Results showed that the nitrogen removal rates was 0.38-0.41 kg N m(-3) day(-1) in the FCBC filled BAF and reached 0.62 kg N m(-3) day(-1) within the filter depth of 60-80 cm, under the conditions of the dissolved oxygen 3.5 ± 0.2 mg L(-1) and the inlet pH 7.2 ± 0.1. Hydrogenophaga (using hydrogen as electron donor), Sphaerotilus (absorbing [Fe(3+)]), Nitrospira (nitrificaion), and Nitrosomonas (ammonia oxidation) were found to be the predominant genera in the reactor. The reaction schemes in the FCBC filled in BAF was calculated: hydrogen and [Fe(3+)] were produced by Fe(0)-C galvanic cells in the FCBC, ammonia was oxidized into nitrate by Nitrosomonas and Nitrospira genera, hydrogen was used as electron donors by Hydrogenophaga genus to reduce nitrate into N2, and [Fe(3+)] was partly absorbed by Sphaerotilus and diverted via sludge discharging. PMID:26638971

  9. Modeling High Rate Phosphorus and Nitrogen Removal in a Vertical Flow Alum Sludge based Constructed Wetlands

    Science.gov (United States)

    Jeyakumar, Lordwin; Zhao, Yaqian

    2014-05-01

    Increased awareness of the impacts of diffuse pollution and their intensification has pushed forward the need for the development of low-cost wastewater treatment techniques. One of such efforts is the use of novel DASC (Dewatered Alum Sludge Cakes) based constructed wetlands (CWs) for removing nutrients, organics, trace elements and other pollutants from wastewater. Understanding of the processes in CWs requires a numerical model that describes the biochemical transformation and degradation processes in subsurface vertical flow (VF) CWs. Therefore, this research focuses on the development of a process-based model for phosphorus (P) and nitrogen (N) removal to achieve a stable performance by using DASC as a substrate in CWs treatment system. An object-oriented modelling tool known as "STELLA" which works based on the principle of system dynamics is used for the development of P and N model. The core objective of the modelling work is oriented towards understanding the process in DASC-based CWs and optimizes design criteria. The P and N dynamic model is developed for DASC-based CWs. The P model developed exclusively for DASC-based CW was able to simulate the effluent P concentration leaving the system satisfactorily. Moreover, the developed P dynamic model has identified the major P pathways as adsorption (72%) followed by plant uptake (20%) and microbial uptake (7%) in single-stage laboratory scale DASC-based CW. Similarly, P dynamic simulation model was developed to simulate the four-stage laboratory scale DASC-based CWs. It was found that simulated and observed values of P removal were in good agreement. The fate of P in all the four stages clearly shows that adsorption played a pivotal role in each stage of the system due to the use of the DASC as a substrate. P adsorption by wetland substrate/DASC represents 59-75% of total P reduction. Subsequently, plant uptake and microbial uptake have lesser role regarding P removal (as compared to adsorption).With regard

  10. The removal of concrete layers from biological shields by microwaves

    International Nuclear Information System (INIS)

    Concrete blocks reinforced with steel bars have been subjected to microwave attack at a frequency of 896 MHz at power levels up to 25 kW. The surface concrete has been explosively removed to the depth of the reinforcement, 10 cm, at a rate of about 2 litres per kWh. Heating was localized around the point of attack, with temperatures up to 3000C at the fractured face being attained. A simple mathematical model of the propagation and absorption of micro-waves was used to estimate the temperature rise of concrete at microwave frequencies of 896 wand 2450 MHz, at different power levels with and without the presence of reinforcing bars. This demonstrated that reinforcement is expected to significantly increase the temperature rise in the concrete between the irradiated surface and the reinforcement, and that near-surface heating should be more rapid at the higher frequency. There was reasonable agreement between predicted and observed temperature at the higher power levels. Further desk and laboratory studies are proposed before proceeding to a fullscale practical demolition machine and the requirements for a prototype remotely-operated demonstration system have been identified. This consists of a static generator of high power (at least 50 kW) transmitting microwaves via a steerable waveguide to a remote applicator mounted on a simple three-axis manipulator capable of traversing realistically large concrete test panels

  11. Selection of controlled variables in bioprocesses. Application to a SHARON-Anammox process for autotrophic nitrogen removal

    DEFF Research Database (Denmark)

    Mauricio Iglesias, Miguel; Valverde Perez, Borja; Sin, Gürkan

    Selecting the right controlled variables in a bioprocess is challenging since the objectives of the process (yields, product or substrate concentration) are difficult to relate with a given actuator. We apply here process control tools that can be used to assist in the selection of controlled...... variables to the case of the SHARON-Anammox process for autotrophic nitrogen removal....

  12. Comparative genomics of two 'Candidatus Accumulibacter' clades performing biological phosphorus removal.

    Science.gov (United States)

    Flowers, Jason J; He, Shaomei; Malfatti, Stephanie; del Rio, Tijana Glavina; Tringe, Susannah G; Hugenholtz, Philip; McMahon, Katherine D

    2013-12-01

    Members of the genus Candidatus Accumulibacter are important in many wastewater treatment systems performing enhanced biological phosphorus removal (EBPR). The Accumulibacter lineage can be subdivided phylogenetically into multiple clades, and previous work showed that these clades are ecologically distinct. The complete genome of Candidatus Accumulibacter phosphatis strain UW-1, a member of Clade IIA, was previously sequenced. Here, we report a draft genome sequence of Candidatus Accumulibacter spp. strain UW-2, a member of Clade IA, assembled following shotgun metagenomic sequencing of laboratory-scale bioreactor sludge. We estimate the genome to be 80-90% complete. Although the two clades share 16S rRNA sequence identity of >98.0%, we observed a remarkable lack of synteny between the two genomes. We identified 2317 genes shared between the two genomes, with an average nucleotide identity (ANI) of 78.3%, and accounting for 49% of genes in the UW-1 genome. Unlike UW-1, the UW-2 genome seemed to lack genes for nitrogen fixation and carbon fixation. Despite these differences, metabolic genes essential for denitrification and EBPR, including carbon storage polymer and polyphosphate metabolism, were conserved in both genomes. The ANI from genes associated with EBPR was statistically higher than that from genes not associated with EBPR, indicating a high selective pressure in EBPR systems. Further, we identified genomic islands of foreign origins including a near-complete lysogenic phage in the Clade IA genome. Interestingly, Clade IA appeared to be more phage susceptible based on it containing only a single Clustered Regularly Interspaced Short Palindromic Repeats locus as compared with the two found in Clade IIA. Overall, the comparative analysis provided a genetic basis to understand physiological differences and ecological niches of Accumulibacter populations, and highlights the importance of diversity in maintaining system functional resilience. PMID:23887171

  13. Implementation of biological nutrient removal from municipal wastewater in Finland - HUT/Savonlinna process, a challenge to the UCT process; Asumisjaeteveden biologisen ravinteiden poiston toteuttaminen Suomen oloissa - HUT/Savonlinna-prosessi UCT-prosessin haastajana

    Energy Technology Data Exchange (ETDEWEB)

    Kiuru, H. [Helsinki Univ. of Technology, Otaniemi (Finland)

    2000-07-01

    The laboratory for Environmental Engineering at the Helsinki University of Technology carried out two successive full-scale R and D projects on biological nutrient removal. As a result of these projects, Pihlajaniemi Wastewater Treatment at Savonlinna in 1991-1996, an activated sludge process, called the HUT/Savonlinna process, was developed. By making use of the organic carbon in wastewater and without any added chemicals, the process is able to reduce the phosphorus content of water by more than 90% and the nitrogen content by about 70%. Total phosphorus contents averaging less than 0.5 mg/l and total nitrogen contents of 8-12 mg/l are usual in the secondary settled wastewater. These projects demonstrated that biological nutrient removal from domestic wastewater would best be started in Finland with year-round complete nitrification. This is the most demanding phase in the removal of biological nutrients from municipal wastewater and also the most expensive way to treat municipal wastewater with the conventional aerated activated sludge process. From there, it would be natural to proceed to effective nitrogen removal by means of denitrification. In that way the operating costs of the treatment plant would be markedly reduced. Nitrogen removal could be implemented without any extension of the treatment plant beyond what would be needed for complete year-round nitrification. The chemical removal of phosphorus from wastewater carried out as simultaneous precipitation could then easily replaced by biological phosphorus removal. This procedure would bring the operating costs of the treatment plant below the level normal in the conventional treatment of municipal wastewaters with an activated sludge process with simultaneous phosphorus precipitation. For this modification the treatment plants would not even have to be enlarged. When biological nutrient removal from municipal wastewaters is implemented in Finland, the HUT/Savonlinna process will surely challenge the UCT

  14. Heavy metal ion removal by adsorption on to biological materials

    International Nuclear Information System (INIS)

    The development of regulations constraints in the industrial waste-waters management leads to the study of new treatment processes, using raw or functionalized biological materials. These processes show competitive performances in metal ion sorption efficiency for the low metal content effluents. Uptake capacities of Uranium as high as 400 mg.g-1 chitosan, equivalent to the double of the uptake capacity of fungal origin biomass, can be reached. The application of these processes to real mine wastewaters gives efficiency coefficient upper to 90%, the residual concentrations are compatible to a direct injection into the environment. The grafting of functional groups onto the chitosan scales up the sorption performances to uptake capacity upper than 600 mg.g-1 polymer. pH, metal concentration are cited as major parameters, particle size influences both uptake kinetics and sorption equilibrium, in the case of the uranium accumulation by chitosan. The desorption of uranium from the sorbent allows the valorization of uranium and the re-use of the sorbent. (authors). 21 refs., 10 figs

  15. [Diversity of nitrogen-fixing microorganisms in biological soil crusts of copper mine wastelands].

    Science.gov (United States)

    Zhan, Jing; Yang, Gui-De; Sun, Qing-Ye

    2014-06-01

    Biological soil crusts play an important role in increasing the accumulation of organic matter and nitrogen in re-vegetated mining wastelands. The diversity of nitrogen-fixing microorganisms in three types of biological soil crusts (algal crust, moss crust and algal-moss crust) from two wastelands of copper mine tailings were investigated by polymerase chain reaction-denaturing gradient gel electrophoresis, based on the nifH gene of diazotrophs, to investigate: The diversity of nifH gene in the crusts of mine wastelands, and whether and how the nifH gene diversity in the crusts could be affected by the development of plant communities. The algal crust on the barren area displayed the highest nifH gene diversity, followed by the algal-moss crusts within vascular plant communities, and the moss crust displayed the lowest nifH gene diversity. The diversity of diazotrophs in algal-moss crust within vascular plant communities decreased with the increase of height and cover of vascular plant communities. No significant relationship was found between wasteland properties (pH, water content, contents of organic matter, nitrogen and phosphorus and heavy metal concentration) and nifH gene diversity in the crusts. Sequencing and phylogenetic analysis indicated that most nitrogen-fixing taxa in the crusts of mine wastelands belonged to Cyanobacteria, especially nonheterocystous filamentous Cyanobacteria. PMID:25223036

  16. Nitrogen removal performance in planted and unplanted horizontal subsurface flow constructed wetlands treating different influent COD/N ratios.

    Science.gov (United States)

    Wang, Wei; Ding, Yi; Ullman, Jeffrey L; Ambrose, Richard F; Wang, Yuhui; Song, Xinshan; Zhao, Zhimiao

    2016-05-01

    Microcosm horizontal subsurface flow constructed wetlands (HSSFCWs) were used to examine the impacts of vegetation on nitrogen dynamics treating different influent COD/N ratios (1:1, 4:1, and 8:1). An increase in the COD/N ratio led to increased reductions in NO3 and total inorganic nitrogen (TIN) in planted and unplanted wetlands, but diminished removal of NH4. The HSSFCW planted with Canna indica L. exhibited a significant reduction in NH4 compared to the unplanted system, particularly in the active root zone where NH4 removal performance increased by up to 26 % at the COD/N ratio of 8:1. There was no significant difference in NO3 removal between the planted and unplanted wetlands. TIN removal efficiency in the planted wetland increased with COD/N ratios, which was likely influenced by plant uptake. NH4 reductions were greater in planted wetland at the 20- and 40-cm depths while NO3 reductions were uniformly greater with depth in all cases, but no statistical difference was impacted by depth on TIN removal. These findings show that planting a HSSFCW can provide some benefit in reducing nitrogen loads in effluents, but only when a sufficient carbon source is present. PMID:26822218

  17. The acclimation of Chlorella to high-level nitrite for potential application in biological NOx removal from industrial flue gases.

    Science.gov (United States)

    Li, Tianpei; Xu, Gang; Rong, Junfeng; Chen, Hui; He, Chenliu; Giordano, Mario; Wang, Qiang

    2016-05-20

    Nitrogen oxides (NOx) are the components of fossil flue gas that give rise to the greatest environmental concerns. This study evaluated the ability of the green algae Chlorella to acclimate to high level of NOx and the potential utilization of Chlorella strains in biological NOx removal (DeNOx) from industrial flue gases. Fifteen Chlorella strains were subject to high-level of nitrite (HN, 176.5 mmolL(-1) nitrite) to simulate exposure to high NOx. These strains were subsequently divided into four groups with respect to their ability to tolerate nitrite (excellent, good, fair, and poor). One strain from each group was selected to evaluate their photosynthetic response to HN condition, and the nitrite adaptability of the four Chlorella strains were further identified by using chlorophyll fluorescence. The outcome of our experiments shows that, although high concentrations of nitrite overall negatively affect growth and photosynthesis of Chlorella strains, the degree of nitrite tolerance is a strain-specific feature. Some Chlorella strains have an appreciably higher ability to acclimate to high-level of nitrite. Acclimation is achieved through a three-step process of restrict, acclimate, and thriving. Notably, Chlorella sp. C2 was found to have a high tolerance and to rapidly acclimate to high concentrations of nitrite; it is therefore a promising candidate for microalgae-based biological NOx removal. PMID:27010349

  18. Effect of Organic Amendments and Inorganic Nitrogen on Biological and Chemical Degradation of Atrazine in Soil

    OpenAIRE

    E Ranjbar; G.H. Haghnia; A. Lakzian; A Fotovat

    2010-01-01

    This study was conducted to compare the impact of various organic amendments with different C/N ratios and chemical compositions on biological and chemical degradation of Atrazine in sterile and non-sterile soils. The experiment was carried out in a factorial arrangement (2×6×2) including two soil types (sterile and non sterile soils), six types of organic amendments (vermicompost, cow manure, glucose, starch and sawdust and without organic matter) and two levels of inorganic nitrogen fertili...

  19. Inorganic sulfur–nitrogen compounds: from gunpowder chemistry to the forefront of biological signaling

    OpenAIRE

    Miriam M. Cortese-Krott; Butler, Anthony R; Woollins, J. Derek; Feelisch, Martin

    2016-01-01

    The reactions between inorganic sulfur and nitrogen-bearing compounds to form S–N containing species have a long history and, besides assuming importance in industrial synthetic processes, are of relevance to microbial metabolism; waste water treatment; aquatic, soil and atmospheric chemistry; and combustion processes. The recent discovery that hydrogen sulfide and nitric oxide exert often similar, sometimes mutually dependent effects in a variety of biological systems, and that the chemical ...

  20. Nitrogen compounds and polysaccharides changes during the biological ageing of sherry wines

    OpenAIRE

    Villamiel, Mar; Polo, María Carmen; Moreno-Arribas, M. Victoria

    2008-01-01

    Biologically aged sherry wines are elaborated by the so called "criadera" and "solera" system, which essentially involves development of the yeast on the wine surface forming a film velum for several years. In this work, a study on the changes that take place in polysaccharide and nitrogen compounds during the elaboration of sherry wines has been undertaken. The evolution of monosaccharides derived from polysaccharides as well as of amino acids and polypeptides have been investigated in wine ...

  1. Effect of dissolved organic matter on nitrate-nitrogen removal by anion exchange resin and kinetics studies

    Institute of Scientific and Technical Information of China (English)

    Haiou Song; Zhijian Yao; Mengqiao Wang; Jinnan Wang; Zhaolian Zhu; Aimin Li

    2013-01-01

    The effects of dissolved organic matter (DOM) on the removal of nitrate-nitrogen from the model contaminated water have been investigated utilizing the strong base anion exchange resins.With the increase of gallic acid concentration from 0 to 400 mg/L,the adsorption amount of nitrate-nitrogen on the commercial resins,including D201,Purolite A 300 (A300) and Purolite A 520E (A520E),would significantly decrease.However,the presence of tannin acid has little impact on nitrate-nitrogen adsorption on them.Compared to D201 and A300 resins,A520E resin exhibited more preferable adsorption ability toward nitrate-nitrogen in the presence of competing organic molecules,such as gallic acid and tannin acid at greater levels in aqueous solution.Attractively,the equilibrium data showed that the adsorption isotherm of nitrate-nitrogen on A520E resin was in good agreement with Langmuir and Freundlich equations.The rate parameters for the intra particle diffusion have been estimated for the different initial concentrations.In batch adsorption processes,nitrate-nitrogen diffuse in porous adsorbent and rate process usually depends on t1/2 rather than the contact time.The pseudo first-and the second-order kinetic models fit better for nitrate-nitrogen adsorption onto A520E resin.The observations reported herein illustrated that A520E resin will be an excellent adsorbent for enhanced removal of nitrate-nitrogen from contaminated groundwater.

  2. Planetary Biology and Microbial Ecology: Molecular Ecology and the Global Nitrogen cycle

    Science.gov (United States)

    Nealson, Molly Stone (Editor); Nealson, Kenneth H. (Editor)

    1993-01-01

    This report summarizes the results of the Planetary Biology and Molecular Ecology's summer 1991 program, which was held at the Marine Biological Laboratory in Woods Hole, Massachusetts. The purpose of the interdisciplinary PBME program is to integrate, via lectures and laboratory work, the contributions of university and NASA scientists and student interns. The goals of the 1991 program were to examine several aspects of the biogeochemistry of the nitrogen cycle and to teach the application of modern methods of molecular genetics to field studies of organisms. Descriptions of the laboratory projects and protocols and abstracts and references of the lectures are presented.

  3. Nitrate removal in deep sediments of a nitrogen-rich river network: A test of a conceptual model

    Science.gov (United States)

    Stelzer, Robert S.; Bartsch, Lynn A.

    2012-06-01

    Many estimates of nitrogen removal in streams and watersheds do not include or account for nitrate removal in deep sediments, particularly in gaining streams. We developed and tested a conceptual model for nitrate removal in deep sediments in a nitrogen-rich river network. The model predicts that oxic, nitrate-rich groundwater will become depleted in nitrate as groundwater upwelling through sediments encounters a zone that contains buried particulate organic carbon, which promotes redox conditions favorable for nitrate removal. We tested the model at eight sites in upwelling reaches of lotic ecosystems in the Waupaca River Watershed that varied by three orders of magnitude in groundwater nitrate concentration. We measured denitrification potential in sediment core sections to 30 cm and developed vertical nitrate profiles to a depth of about 1 m with peepers and piezometer nests. Denitrification potential was higher on average in shallower core sections. However, core sections deeper than 5 cm accounted for 70% on average of the depth-integrated denitrification potential. Denitrification potential increased linearly with groundwater nitrate concentration up to 2 mg NO3-N/L, but the relationship broke down at higher concentrations (>5 mg NO3-N/L), a pattern that suggests nitrate saturation. At most sites groundwater nitrate declined from high concentrations at depth to much lower concentrations prior to discharge into the surface water. The profiles suggested that nitrate removal occurred at sediment depths between 20 and 40 cm. Dissolved oxygen concentrations were much higher in deep sediments than in pore water at 5 cm sediment depth at most locations. The substantial denitrification potential in deep sediments coupled with the declines in nitrate and dissolved oxygen concentrations in upwelling groundwater suggest that our conceptual model for nitrate removal in deep sediments is applicable to this river network. Our results suggest that nitrate removal rates can

  4. Enhanced biological phosphorus removal in the wastewater treatment plant of Bunnik

    Energy Technology Data Exchange (ETDEWEB)

    Vries, H.P. de; Rensink, J.H.

    1989-02-01

    At several sewage treatment plants in the Netherlands there has been continuously found a remarkable high phosphorus removal rate, without using chemical additions. In Bunnik this is up to 90%. In the effluent we will mostly find less than 1 mg P/l. At the Bunnik plant we deal with biological excess phosphorus removal. Biological phosphorus removal is based on the luxury uptake of phosphorus by some bacteria. On certain circumstances micro-organisms of the genius Acinetobacter stored excess amounts of phosphates in their cells. In 1984 a project started, financed by the institute for inland waters and wastewater treatment (DBW/RIZA). The purpose of this research project was to find factors which were, responsible for the remarkable enhanced phosphorus removal in the Bunnik plant.

  5. Removal of disinfection by-product formation potentials by biologically assisted GAC treatment

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The object of this paper is to evaluate the removal of disinfection by-products formation potential by artificially intensified biological activated carbon(BAC) process which is developed on the basis of traditional ozone granular activated carbon (GAC). The results show that 23.1% of trihalomethane formation potential (THMFP) and 68% of haloacetic acid formation potential (HAAFP) can be removed by BAC,respectively. Under the same conditions, the removal rates of the same substances were 12.2% and 13-25 % respectively only by GAC process. Compared with GAC, the high removal rates of the two formed potential substances were due to the increasing of bioactivity of the media and the synergistic capabilities of biological degradation cooperating with activated carbon adsorption of organic compounds. BAC process has some advantages such as long backwashing cycle time, low backwashing intensity and prolonged activated carbon lifetime, etc.

  6. Autotrophic and heterotrophic denitrification for simultaneous removal of nitrogen, sulfur and organic matter.

    Science.gov (United States)

    Guerrero, Lorna; Aguirre, Juan P; Muñoz, Maria A; Barahona, Andrea; Huiliñir, Cesar; Montalvo, Silvio; Borja, Rafael

    2016-07-01

    The aim of this investigation was to assess the startup and operation of a laboratory-scale hybrid UASB-Anaerobic Filter Reactor (UASFB) of 1 L volume, kept at 30°C, in order to carry out a simultaneous autotrophic and heterotrophic denitrification process. First, the heterotrophic and autotrophic populations were separately enriched, with specific cultures and subsequently the UASFB was inoculated with 2 g L(-1) of volatile suspended solids (VSS), with a ratio of 1.5:1 (autotrophs: heterotrophs). The influent or synthetic wastewater used was composed of: Na2S2O3·5H2O, CH3COOK, NaNO3, NaHCO3, K2HPO4, NH4Cl and saline solution. The concentrations varied depending on the organic loading rate (OLR), nitrogen loading rate (NLR) and sulfur loading rate (SLR) applied. In the UASFB reactor, two experimental conditions were tested and assessed: (i) COD/N ratio of 3.6 and SLR of 0.75 kg S m(-3) d(-1); and (ii) COD/N ratio of 5.8 and SLR of 0.25 kg S m(-3) d(-1). The results obtained demonstrated that an inoculum coming from an anaerobic reactor was able to carry out the process, obtaining a maximum nitrate removal of 85.3% in the first stage of operation and 99.5% in the second stage. The recovery of sulfur in form of sulfate in the effluent did not present a tendency to stabilize during the measured time, with a maximum thiosulfate removal of 32.5%, when the SLR was lowered to 0.25 kg S m(-3) d(-1). The maximum organic matter elimination, measured as COD, was 75.8%, which indicates the relatively good performance and behavior of the heterotrophic microorganisms. PMID:27093220

  7. Biological phosphorus removal during high-rate, low-temperature, anaerobic digestion of wastewater

    OpenAIRE

    Ciara eKeating; Chin, Jason P.; Dermot eHughes; Panagiotis eManesiotis; Denise eCysneiros; Therese eMahony; Smith, Cindy J; John W McGrath; Vincent eO'Flaherty

    2016-01-01

    We report, for the first time, extensive biologically-mediated phosphate removal from wastewater during high-rate anaerobic digestion (AD). A hybrid sludge bed/fixed-film (packed pumice stone) reactor was employed for low-temperature (12°C) anaerobic treatment of synthetic sewage wastewater. Successful phosphate removal from the wastewater (up to 78% of influent phosphate) was observed, mediated by biofilms in the reactor. Scanning electron microscopy and energy dispersive X-ray analysis reve...

  8. A metagenome of a full-scale microbial community carrying out enhanced biological phosphorus removal

    OpenAIRE

    Albertsen, Mads; Hansen, Lea Benedicte Skov; Saunders, Aaron Marc; Nielsen, Per Halkjær; Nielsen, Kåre Lehmann

    2011-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used for removal of phosphorus from wastewater. In this study, a metagenome (18.2 Gb) was generated using Illumina sequencing from a full-scale EBPR plant to study the community structure and genetic potential. Quantitative fluorescence in situ hybridization (qFISH) was applied as an independent method to evaluate the community structure. The results were in qualitative agreement, but a DNA extraction bias against gram positive bacteria ...

  9. Integrative microbial community analysis reveals full-scale enhanced biological phosphorus removal under tropical conditions

    OpenAIRE

    Yingyu Law; Rasmus Hansen Kirkegaard; Angel Anisa Cokro; Xianghui Liu; Krithika Arumugam; Chao Xie; Mikkel Stokholm-Bjerregaard; Drautz-Moses, Daniela I.; Per Halkjær Nielsen; Stefan Wuertz; Rohan B. H. Williams

    2016-01-01

    Management of phosphorus discharge from human waste is essential for the control of eutrophication in surface waters. Enhanced biological phosphorus removal (EBPR) is a sustainable, efficient way of removing phosphorus from waste water without employing chemical precipitation, but is assumed unachievable in tropical temperatures due to conditions that favour glycogen accumulating organisms (GAOs) over polyphosphate accumulating organisms (PAOs). Here, we show these assumptions are unfounded b...

  10. Biological Phosphorus Removal During High-Rate, Low-Temperature, Anaerobic Digestion of Wastewater

    OpenAIRE

    Keating, Ciara; Chin, Jason P.; Hughes, Dermot; Manesiotis, Panagiotis; Cysneiros, Denise; Mahony, Therese; Smith, Cindy J; John W McGrath; O’Flaherty, Vincent

    2016-01-01

    We report, for the first time, extensive biologically mediated phosphate removal from wastewater during high-rate anaerobic digestion (AD). A hybrid sludge bed/fixed-film (packed pumice stone) reactor was employed for low-temperature (12°C) anaerobic treatment of synthetic sewage wastewater. Successful phosphate removal from the wastewater (up to 78% of influent phosphate) was observed, mediated by biofilms in the reactor. Scanning electron microscopy and energy dispersive X-ray analysis reve...

  11. Application of chemical oxidation processes for the removal of pharmaceuticals in biologically treated wastewater

    OpenAIRE

    Hey, Gerly

    2013-01-01

    The discharge of effluents from wastewater treatment plants (WWTPs) is considered to be the major source of residual pharmaceuticals frequently found in aquatic environments. The complex nature of such compounds tends to make conventional biological treatments aimed at their removal ineffective. The present thesis concerns the removal of 62 different active pharmaceutical ingredients commonly detected in Swedish wastewater effluents by means of chemical oxidation techniques. Techniques wit...

  12. The effect of key process operational conditions on enhanced biological phosphorus removal from wastewater

    OpenAIRE

    Carvalheira, Mónica Isabel Gonçalves

    2014-01-01

    Enhanced biological phosphorus removal (EBPR) is the most economic and sustainable option used in wastewater treatment plants (WWTPs) for phosphorus removal. In this process it is important to control the competition between polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs), since EBPR deterioration or failure can be related with the proliferation of GAOs over PAOs. This thesis is focused on the effect of operational conditions (volatile fatty acid (VFA) c...

  13. Full-scale biological phosphorus removal: quantification of storage polymers, microbial performance and metabolic modelling

    OpenAIRE

    Lanham, Ana Alexandra Barbosa

    2012-01-01

    Enhanced biological phosphorus removal (EBPR) can be applied in wastewater treatment plants (WWTPs), as a sustainable and efficient way to remove phosphorus from wastewater and hence reduce its impact on eutrophication. This work characterises the performance, metabolism and identity of the microbial EBPR communities in full-scale WWTPs. The accurate quantification of the internal storage compounds, namely polyhydroxyalkanoate (PHA) and glycogen, is crucial to the characterisat...

  14. Fouling of enhanced biological phosphorus removal-membrane bioreactors by humic-like substances.

    Science.gov (United States)

    Poorasgari, Eskandar; König, Katja; Fojan, Peter; Keiding, Kristian; Christensen, Morten Lykkegaard

    2014-12-01

    Fouling by free extracellular polymeric substances was studied in an enhanced biological phosphorus removal-membrane bioreactor. It was demonstrated that the free extracellular polymeric substances, primarily consisting of humic-like substances, were adsorbed to the membrane used in the enhanced biological phosphorus removal-membrane bioreactor plant. Infrared analyses indicated the presence of the humic-like substances on the membrane's active surface after filtration of the free extracellular polymeric substances suspension. Scanning electron microscopy showed the presence of a gel layer on the membrane surface after filtration of the free extracellular polymeric substances suspension. The gel layer caused a significant decline in water flux. This layer was not entirely removed by a backwashing, and the membrane's water flux could not be re-established. The membrane used in the enhanced biological phosphorus removal-membrane bioreactor plant showed infrared spectra similar to that fouled by the free extracellular polymeric substances suspension in the laboratory. Thus, the results of this study show the importance of humic-like substances in irreversible fouling of enhanced biological phosphorus removal-membrane bioreactor systems. PMID:25014564

  15. [Review on the main microorganisms and their metabolic mechanisms in enhanced biological phosphorus removal (EBPR) systems].

    Science.gov (United States)

    Sun, Xue; Zhu, Wei-Jing; Wang, Liang; Wu, Wei-Xiang

    2014-03-01

    Enhanced biological phosphorus removal (EBPR) process is applied widely for removing phosphorus from wastewater. Studies on functional microorganisms and their metabolic mechanisms are fundamental to effective regulation for stable operation and performance improvement of EBPR process. Two main types of microorganisms in EBPR systems, polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) were selected to summarize their metabolic mechanisms such as substrate uptake mechanisms, glycogen degradation pathways, extent of TCA cycle involvement and metabolic similarity between PAOs and GAOs. Application of molecular biology techniques in microbiology and metabolic mechanisms involved in the EBPR system was evaluated. Potential future research areas for the EBPR system and process optimization were also proposed. PMID:24984512

  16. Nitrogen removal in the bioreactor landfill system with intermittent aeration at the top of landfilled waste

    International Nuclear Information System (INIS)

    High ammonia concentration of recycled landfill leachate makes it very difficult to treat. In this work, a vertical aerobic/anoxic/anaerobic lab-scale bioreactor landfill system, which was constructed by intermittent aeration at the top of landfilled waste, as a bioreactor for in situ nitrogen removal was investigated during waste stabilization. Intermittent aeration at the top of landfilled waste might stimulate the growth of nitrifying bacteria and denitrifying bacteria in the top and middle layers of waste. The nitrifying bacteria population for the landfill bioreactor with intermittent aeration system reached between106 and 108 cells/dry g waste, although it decreased 2 orders of magnitude on day 30, due to the inhibitory effect of the acid environment and high organic matter in the landfilled waste. The denitrifying bacteria population increased by between 4 and 13 orders of magnitude compared with conventional anaerobic landfilled waste layers. Leachate NO3--N concentration was very low in both two experimental landfill reactors. After 105 days operation, leachate NH4+-N and TN concentrations for the landfill reactor with intermittent aeration system dropped to 186 and 289 mg/l, respectively, while they were still kept above 1000 mg/l for the landfill reactor without intermittent aerobic system. In addition, there is an increase in the rate of waste stabilization as well as an increase of 12% in the total waste settlement for the landfill reactor with intermittent aeration system

  17. Observation of Nitrogen and Phosphorus Removals and Accumulations in Surface Flow Constructed Wetland (SFCW

    Directory of Open Access Journals (Sweden)

    Suntud Sirianuntapiboon

    2012-06-01

    Full Text Available The tropical emergent plant species; Cyperus involucratus, Canna siamensis, Heliconia sp., Hymenocallis littoralis, Typha augustifolia and Thalia dealbata were used to observe nutrients (total phosphorus: TP and total nitrogen: TN removal efficiencies of surface flow constructed wetland (SFCW. The system was operated at different hydraulic retention time (HRT of 1, 3 and 5 days and the average atmospheric temperature of 29.1 ± 4.9oC. The seafood industrial wastewater was employed as the influent. The high biomass production plant species; Cyperus involucratus, Typha augustifolia and Thalia dealbata could generate the high oxidative environment. Amount of N and P accumulations in plant tissue were increased with the increase of plant biomass production. The system did not show any significantly different on N and P accumulations among the tested-emergent plant species. But the amount of accumulated-N and P were increased with the increase of HRT. N accumulations in plant tissue, effluent, sediment and media of the system with the tested-emergent plant species under HRT of 1-5 days were in the range of 2.17-43.80%, 7.91-27.75%, 19.62-36.86% and 14.39-31.88%, respectively. Also, P accumulations were 0.79-17.01%, 20.35-28.37%, 40.96-56.27% and 9.09-20.47%, respectively.

  18. Integrating landfill bioreactors, partial nitritation and anammox process for methane recovery and nitrogen removal from leachate

    Science.gov (United States)

    Sun, Faqian; Su, Xiaomei; Kang, Tingting; Wu, Songwei; Yuan, Mengdong; Zhu, Jing; Zhang, Xiayun; Xu, Fang; Wu, Weixiang

    2016-06-01

    A new process consisting of a landfill bioreactor, partial-nitritation (PN) and the anammox process has been developed for landfill leachate treatment. In this study, the landfill bioreactor exhibited excellent performance in methane-rich biogas recovery, with a specific biogas yield of 0.47 L gas g‑1 COD and methane percentages of 53–76%. PN was achieved in the aerobic reactor by high free ammonia (101 ± 83 mg NH3 L‑1) inhibition for nitrite-oxidizing bacteria, and the desired PN effluent composition (effluent nitrite: ammonium ratio of 1.1 ± 0.3) was controlled by adjusting the alkalinity concentration per unit of ammonium oxidized to approximately 14.3 mg CaCO3 mg‑1 N in the influent. The startup of anammox process was successfully achieved with a membrane bioreactor in 160 d, and a maximum nitrogen removal rate of 216 mg N L‑1 d‑1 was attained for real landfill leachate treatment. The quantitative polymerase chain reaction results confirmed that the cell-specific anammox activity was approximately 68–95 fmol N cell‑1 d‑1, which finally led to the stable operation of the system.

  19. Characterization of the start-up period of single-step autotrophic nitrogen removal in a sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    GUO Jin-song; QIN Yu; FANG Fang; YANG Guo-hong

    2008-01-01

    The characteristics of the start-up period of single-step autotrophic nitrogen removal process were investigated. The autotrophic nitrogen removal process used a sequencing batch reactor to treat wastewater of medium to low ammonia-nitrogen concentration, with dissolved oxygen (DO), hydraulic retention time (HRT) and temperature controlled. The experimental conditions were temperature at (30(2) (C, ammonia concentration of (60 to 120) mg/L, DO of (0.8 to 1.0) mg/L, pH from 7.8 to 8.5 and HRT of 24 h. The rates of nitrification and nitrogen removal turn out to be 77% and 40%, respectively, after a start up period going through three stages divided according to nitrite accumulation: sludge domestication, nitrifying bacteria selection and sludge adaptation. It is demonstrated that dissolved oxygen is critical to nitrite accumulation and elastic YJZH soft compound packing is superior to polyhedral hollow balls in helping the bacteria adhere to the membrane.

  20. EFFICIENCY OF NITROGEN REMOVAL IN CONSTRUCTED WETLAND:A SIMULATION STUDY IN THE WEST JINLIN,CHINA

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hu-Cheng; YU Mu-Qing; TIAN Wei; YU Jian; FU You-Bao; WANG Xiao-Dong

    2004-01-01

    Plenty of inorganic nitrogen in wastewater can cause the eutrophication in water bodies, so it is an important task to remove nitrogen. Purification role was realized by absorption, filtration, depositon, evaporation, nitrification and denitrification of microbes. Although the studies of Phragmites austrilis bed in the constructed wetland are popular, the purification performances of constructed wetland filled by saline-alkali soil substrate are less reported. In the paper, the purification efficiency of nitrogen with Phragmites austrilis bed in the constructed wetland filled by saline-alkali soil substrate was discussed through a simulation study. Results to date indicated that the first order plug flow model was adequate to describe the nitrogen removal. The experiment showed that the diminishing concentration of TN, NO2-N, NO3-N, NH4-N were closely related to hydrological retention time (HRT), the correlation coefficient was Re = 0.98499, R2 = 0. 9911, R2 = 0. 89407 and R2 = 0. 95459, respectively. According to the data, the most suitable hydrological retention time (HRT) for this kind of constructed wetland should be determined to 4 days. In addition, the experiment showed the purification efficiency of nitrogen has very broad range and drastic vibration, TN( 17 % - 79%), NO2-N (33 % - 98 %), NO3-N( 13 % - 93 %), NH4-N (28 % - 64%). The study will promote wetland's design and operation procedures in large saline-alkaline soil areas.

  1. Experimental analysis of a nitrogen removal process simulation of wastewater land treatment under three different wheat planting densities

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Nitrogen contaminant transport,transformation and uptake simulation experiments were conducted in green house under three different planting density of winter wheat.They were Group A,planting density of 0.0208 plants/cm2,Group B,0.1042 plants/cm2,and Group C,0.1415 plants/cm2 .The capacity and ratio of nitrogen removal were different on three kinds of conditions of wastewater land treatment.From analysis of wastewater treatment capacity,wastewater concentration and irrigation intensity for Group C were suitable and nitrogen quantity added was 2 times of that for Group B,2.6 times for Group A while nitrogen residue was only 7.06%.Hence,wastewater irrigation and treatment design with purpose of waste water treatment should select the design with maximum capacity,optimal removal ratio and least residue in soil,which was closely related to crop planting density,crop growth status and also background nitrogen quantity in soil.

  2. Temporary storage or permanent removal? The division of nitrogen between biotic assimilation and denitrification in stormwater biofiltration systems.

    Directory of Open Access Journals (Sweden)

    Emily G I Payne

    Full Text Available The long-term efficacy of stormwater treatment systems requires continuous pollutant removal without substantial re-release. Hence, the division of incoming pollutants between temporary and permanent removal pathways is fundamental. This is pertinent to nitrogen, a critical water body pollutant, which on a broad level may be assimilated by plants or microbes and temporarily stored, or transformed by bacteria to gaseous forms and permanently lost via denitrification. Biofiltration systems have demonstrated effective removal of nitrogen from urban stormwater runoff, but to date studies have been limited to a 'black-box' approach. The lack of understanding on internal nitrogen processes constrains future design and threatens the reliability of long-term system performance. While nitrogen processes have been thoroughly studied in other environments, including wastewater treatment wetlands, biofiltration systems differ fundamentally in design and the composition and hydrology of stormwater inflows, with intermittent inundation and prolonged dry periods. Two mesocosm experiments were conducted to investigate biofilter nitrogen processes using the stable isotope tracer 15NO3(- (nitrate over the course of one inflow event. The immediate partitioning of 15NO3(- between biotic assimilation and denitrification were investigated for a range of different inflow concentrations and plant species. Assimilation was the primary fate for NO3(- under typical stormwater concentrations (∼1-2 mg N/L, contributing an average 89-99% of 15NO3(- processing in biofilter columns containing the most effective plant species, while only 0-3% was denitrified and 0-8% remained in the pore water. Denitrification played a greater role for columns containing less effective species, processing up to 8% of 15NO3(-, and increased further with nitrate loading. This study uniquely applied isotope tracing to biofiltration systems and revealed the dominance of assimilation in stormwater

  3. A strategy for xenobiotic removal using photocatalytic treatment, microbial degradation or integrated photocatalytic-biological process

    OpenAIRE

    Lapertot, Miléna

    2006-01-01

    According to the limited natural resources and due to the risks of anthropogenic pollution, it appears necessary to react efficiently in order to remove existing contaminations and avoid the creation of new ones. Therefore, the purpose of this thesis is to propose a sustainable strategy for treating problematic pollutants with the most adequate process. First, an overview of the different treatment processes has been given. In particular, biological, photocatalytic and integrated biological-p...

  4. A strategy for xenobiotic removal using photocatalytic treatment, microbial degradation or integrated photocatalytic-biological process

    OpenAIRE

    Lapertot, Miléna; Pulgarin, César

    2007-01-01

    According to the limited natural resources and due to the risks of anthropogenic pollution, it appears necessary to react efficiently in order to remove existing contaminations and avoid the creation of new ones. Therefore, the purpose of this thesis is to propose a sustainable strategy for treating problematic pollutants with the most adequate process. First, an overview of the different treatment processes has been given. In particular, biological, photocatalytic and integrated biological-p...

  5. Effects of Solid Retention Time (SRT) on Sludge Characteristics in Enhanced Biological Phosphorus Removal (EBPR) Reactor

    OpenAIRE

    Li, N.; X Wang; N Ren; Zhang, K.; Kang, H; You, S.

    2008-01-01

    This study investigated the effects of solid retention time (SRT) on sludge characteristics and operational performance in enhanced biological phosphorus removal (EBPR) reactor. The results showed that the reactor operated at SRT of τ = 8.3 d could achieve phosphate removal efficiency η > 90 % and SVI < 100 mL g–1. In comparison, increasing SRT to τ = 16.6 d led to a decrease of phosphate removal (η < 85 %) and an increase of SVI value (160 mL g–1), implying a performance degradation and wors...

  6. Operational strategy for nitrogen removal from centrate in a two-stage partial nitrification--anammox process.

    Science.gov (United States)

    Kosari, S F; Rezania, B; Lo, K V; Mavinic, D S

    2014-01-01

    This paper presents the operational strategy for nitrogen removal in a two-stage, partial nitrification (PN) process coupled with anaerobic ammonium oxidation (Anammox) process. The process was used to remove ammonium from centrate obtained from a full-scale, wastewater treatment plant in British Columbia, Canada. The PN, which was carried out in a sequencing batch reactor (SBR), successfully converted approximately 49.5 +/- 1.0% of ammonium to nitrite. The operation of SBR under higher dissolved oxygen in combination with slow feeding resulted in significant reduced HRT without nitrate accumulation. Partially nitrified centrate was further treated in Anammox reactors, where the mixture of ammonium and nitrite was converted mainly to nitrogen gas. Anammox treatment was carried out in two different types of Anammox reactors: a moving bed hybrid reactor and an up-flow fixed-bed biofilm reactor. The hybrid Anammox reactor removed an average of 55.8% of NH4-N, versus the 48.3% NH4-N removed in the up-flow fixed-bed reactor. Nitrite removal in the hybrid and up-flow fixed-bed Anammox reactors averaged 80.8% and 62.5%, respectively. This study also illustrated that in both Anammox reactors, better ammonium removal was achieved when the nitrite to ammonium ratio is between 1.35 and 1.45. As such, alkalinity was found to neither control nor limit the Anammox reaction. PMID:24701906

  7. Rural wastewater irrigation and nitrogen removal by the paddy wetland system in the Tai Lake region of China

    Energy Technology Data Exchange (ETDEWEB)

    Li Song; Chen Yingxu [Inst. of Environmental Science and Tech., Zhejiang Univ. (China); Forest Soil and Environment Joint Labs. of ZJFC-ISSAS, ZJ (China); Li Hua; Liang Xingqiang [Inst. of Environmental Science and Tech., Zhejiang Univ. (China); Cao Zhihong [Forest Soil and Environment Joint Labs. of ZJFC-ISSAS, ZJ (China); Xu Zhihong [Center for Forestry and Horticultural Research, Griffith Univ., Brisbane (Australia)

    2009-10-15

    Background, aim, and scope A large area of water eutrophication in the Tai Lake region of China was associated with nitrogen (N) and phosphorus (P) pollution, mainly due to the discharge of untreated rural wastewater (RW) into the surface water (SW) near villages of this region. A field experiment was conducted, using irrigation of RW plus urea fertilization under equal nitrogen (N) rate, namely, black water (BW), domestic wastewater (DW), gray water (GW), SW, and SW without any N application as a control (CK), to elucidate N removal by the paddy wetland system during the rice growing season of 2007. (orig.)

  8. Nitrogen removal from wastewater and external waste activated sludge reutilization/reduction by simultaneous sludge fermentation, denitrification and anammox (SFDA).

    Science.gov (United States)

    Wang, Bo; Peng, Yongzhen; Guo, Yuanyuan; Zhao, Mengyue; Wang, Shuying

    2016-08-01

    This work demonstrates the feasibility of simultaneous nitrogen removal and external waste activated sludge (WAS) reutilization/reduction by using the synergy of sludge fermentation, denitrification and anammox processes in up-flow reactors (SFDA). Pre-treated domestic wastewater and synthetic wastewater (containing nitrite ∼20mg/L, ammonium ∼10mg/L in both) were fed to 1# and 2# SFDA, respectively. Long-term operation of 1# SFDA was investigated with achieving the peak ammonium removal rate of 0.021 and nitrite removal rate of 0.081kgN/(m(3)d) as nitrogen loading rate elevated from 0.075 to 0.106kgN/(m(3)d). Negative effect of dissolved oxygen on anammox or fermentation in the 2# SFDA was demonstrated negligible due to rapid depletion by microorganisms. Furthermore, a "net" sludge reduction of 38.8% was obtained due to sludge decay and organics consumption by denitrification. The SFDA process was expected to potentially be used for nitrogen removal and WAS reutilization/reduction in full-scale application. PMID:27140818

  9. Simultaneous organic carbon and nitrogen removal in an anoxic-oxic activated sludge system under various operating conditions.

    Science.gov (United States)

    Rasool, Kashif; Ahn, Dae Hee; Lee, Dae Sung

    2014-06-01

    This study investigated a bench-scale anoxic-oxic activated sludge system for integrated removal of COD and nitrogen. The experimental unit includes four chambers and continuous feeding in first chamber without recycle of nitrified liquid from aerobic to anoxic chamber unlike the conventional anoxic-oxic process. Recycled excessive sludge was used for the purpose of recycling nitrified mixed liquor. Synthetic wastewater with average loading rates of 0.53 kg COD/m(3)/d and 0.067 kg NH4(+)-N/m(3)/d was fed to the reactor system at hydraulic residence times (HRT) of 24 and 18 h. The results of 100 days operation showed high removal efficiencies of organic matter of about 97% as total COD and more than 99% removal of ammonia-nitrogen. In anoxic-oxic operation phase, total inorganic nitrogen (TIN) removal was about 66% by pre-denitrification. Moreover, the solid liquid separation through final clarifier was excellent without any suspended solid in the effluent. PMID:24768910

  10. Kinetic analysis of enhanced biological phosphorus removal in a hybrid integrated fixed film activated sludge process

    International Nuclear Information System (INIS)

    Hybrid integrated fixed film activated sludge is a promising process for the enhancement of nitrification, denitrification and phosphorus removal in conventional activated sludge systems that can be used for upgrading biological nutrient removal, particularly when they have space limitations or need modifications that will require large monetary expenses. In this research, successful implementation of hybrid integrated fixed film activated sludge process at temperate zone wastewater treatment facilities has been studied by the placement of fixed film media into aerobic, anaerobic and anoxic zones. The primary objective of this study was to investigate the incorporation of enhanced biological phosphorus removal into hybrid integrated fixed film activated sludge systems and study the interactions between the fixed biomass and the mixed liquor suspended solids with respect to substrate competition and nutrient removal efficiencies. A pilot-scale anaerobic-anoxic-oxic configuration system was used. The system was operated at different mean cell residence times and influent chemical oxygen demand/total phosphorus ratios and with split influent flows. The experimental results confirmed that enhanced biological phosphorus removal could be incorporated successfully into hybrid integrated fixed film activated sludge system, but the redistribution of biomass resulting from the integration of fixed film media and the competition of organic substrate between enhanced biological phosphorus removal and denitrification would affect performances. Also, kinetic analysis of the reactor with regarding to phosphorus removal has been studied with different kinetic models and consequently the modified Stover-Kincannon kinetic model has been chosen for modeling studies and experimental data analysis of the hybrid integrated fixed film activated sludge reactor

  11. Effect of HRT on nitrogen removal in a coupled HRP and unplanted subsurface flow gravel bed constructed wetland

    Science.gov (United States)

    Mayo, A. W.; Mutamba, J.

    This paper discusses the effect of hydraulic retention time (HRT) on nitrogen removal in a coupled high rate pond (HRP) and a gravel bed subsurface constructed wetland (SSCW) wastewater treatment plant. A pilot plant consisting of a high rate pond (HRT) coupled to an unplanted gravel bed subsurface constructed wetland (SSCW) was used to investigate nitrogen removal from domestic wastewater at the University of Dar es Salaam. The influent, which is predominantly of domestic origin, was drawn from the facultative pond unit of the university’s waste stabilisation pond system. The pilot plant’s HRP unit, which was 0.6 m deep, was designed to nitrify the influent while SSCW unit, which was filled to 10 cm above water level with 19-mm diameter aggregates, was predominantly anoxic and promoted denitrification. The study was conducted at two different operational settings. In Phase 1, both the HRP and the SSCW units had a retention time of 5 days. During Phase 2, the hydraulic retention time in HRP was increased to 8 days while the retention time of the SSCW unit was maintained at 5 days. Samples were collected daily for laboratory analysis of influent and effluent wastewater quality. All experiments were conducted in accordance with Standard Methods. The results showed that improved nitrogen removal occurred with increase in hydraulic time of the HRP unit. In Phase 1 an average nitrogen removal of 33% was achieved while removal efficiency improved to 43% in Phase 2. It was also revealed that the HRP can effectively be used to promote nitrification and the unplanted gravel bed subsurface constructed wetland can be used as a denitrifying unit.

  12. EnviroAtlas - Cultivated biological nitrogen fixation in agricultural lands by 12-digit HUC in the Conterminous United States, 2006

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset contains data on the mean cultivated biological nitrogen fixation (C-BNF) in cultivated crop and hay/pasture lands per 12-digit Hydrologic...

  13. Stabilization of organic matter and nitrogen immobilization during mechanical-biological treatment and landfilling of residual municipal solid waste

    International Nuclear Information System (INIS)

    Synthesis of humic substances and nitrogen immobilization during mechanical-biological treatment of waste and the behavior of biologically stabilized waste under anaerobic landfill conditions were investigated. Samples were taken from a large-scale treatment plant. Anaerobic conditions were simulated in lab scale test cells. Humic substances were analyzed photometrically and gravimetrically. The nitrogen immobilization was investigated by sequential leaching tests and by analyzing the non acid hydrolyzable nitrogen. Humic acids were mainly synthesized during the beginning of the intensive rotting phase. Later on in the process no significant changes occurred. The humic acid content rose up to 6,8 % DS org. It correlated well with the stability parameters respiration activity and accumulated gas production. In the coarse of the treatment the nitrogen load emitted during the consecutive leaching tests dropped from 50 % down to less than 20 % total nitrogen. The non acid hydrolyzable nitrogen rose from 17 up to 42 % Kjeldahl nitrogen content. Nevertheless the mechanical-biological treatment is not significantly shortening the aftercare period of a landfill concerning liquid nitrogen emissions. The reduced nitrogen emission potential is released more slowly. When reactive waste material was exposed to anaerobic conditions, humic and fulvic acids were synthesized up to the point when intensive gas production started and then were remineralized. Stabilized waste materials after treatment of various intensity behaved differently under anaerobic conditions. Steady and decreasing humic acid contents were observed. (author)

  14. Biological Nutrient Removal in a Full Scale Anoxic/Anaerobic/Aerobic/Pre-anoxic-MBR Plant for Low C/N Ratio Municipal Wastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    胡香; 谢丽; 张善发; 杨殿海

    2014-01-01

    A novel full scale modified A2O (anoxic/anaerobic/aerobic/pre-anoxic)-membrane bioreactor (MBR) plant combined with the step feed strategy was operated to improve the biological nutrient removal (BNR) from low C/N ratio municipal wastewater in Southern China. Transformation of organic carbon, nitrogen and phosphorus, and membrane fouling were investigated. Experimental results for over four months demonstrated good efficiencies for chemical oxygen demand (COD) and 4NH+-N removal, with average values higher than 84.5%and 98.1%, re-spectively. A relatively higher total nitrogen (TN) removal efficiency (52.1%) was also obtained at low C/N ratio of 3.82, contributed by the configuration modification (anoxic zone before anaerobic zone) and the step feed with a distribution ratio of 1︰1. Addition of sodium acetate into the anoxic zone as the external carbon source, with a theoretical amount of 31.3 mg COD per liter in influent, enhanced denitrification and the TN removal efficiency in-creased to 74.9%. Moreover, the total phosphate (TP) removal efficiency increased by 18.0%. It is suggested that the external carbon source is needed to improve the BNR performance in treating low C/N ratio municipal waste-water in the modified A2O-MBR process.

  15. Long-term nitrogen compound removal trends of a hybrid subsurface constructed wetland treating milking parlor wastewater throughout its 7 years of operation.

    Science.gov (United States)

    Harada, J; Inoue, T; Kato, K; Izumoto, H; Zhang, X; Sakuragi, H; Wu, D; Ietsugu, H; Sugawara, Y

    2016-01-01

    This study evaluated the nitrogen compound removal efficiency of a hybrid subsurface constructed wetland, which began treating milking parlor wastewater in Hokkaido, northern Japan, in 2006. The wetland's overall removal rates of total nitrogen (TN) and ammonium (NH4(+)-N) improved after the second year of operation, and its rate of organic nitrogen (Org-N) removal was stable at 90% efficiency. Only nitrate (NO3(-)-N) levels were increased following the treatment. Despite increased NO3(-)-N (maximum of 3 mg-N/L) levels, TN removal rates were only slightly affected. Removal rates of TN and Org-N were highest in the first vertical bed. NH4(+)-N removal rates were highest in the second vertical bed, presumably due to water recirculation and pH adjustment. Concentrations of NO3(-)-N appeared when total carbon (TC) levels were low, which suggests that low TC prevented complete denitrification in the second vertical bed and the final horizontal bed. In practice, the beds removed more nitrogen than the amount theoretically removed by denitrification, as calculated by the amount of carbon removed from the system. This carbon-nitrogen imbalance may be due to other nitrogen transformation mechanisms, which require less carbon. PMID:26942522

  16. Fermentation of Bioenergy Crops Into Ethanol Using Biological Abatement for Removal of Inhibitors

    Science.gov (United States)

    Conversion of biomass to fuels or chemicals is hampered by the presence of inhibitory compounds contained in sugar streams derived from lignocellulosic biomass. Biological abatement is a promising method for removing these inhibitors because it neither consumes chemicals nor generates wastes. In t...

  17. Biological Ammonia Removal: From Theory to Case Studies in 20 Minutes

    Science.gov (United States)

    This presentation documents the results of two pilot-scale treatment studies, in Ohio and Iowa, that investigated the biological removal of ammonia from ground water. Influent ammonia concentrations in the Ohio and Iowa studies averaged 1.3 and 3.3 mg/L - N, respectively. Both ...

  18. Startup of a biological scrubber for hydrogen sulfide removal from anaerobic digester biogas

    Energy Technology Data Exchange (ETDEWEB)

    Pierkiel, A.; Lanting, J. [Biothane Corp., Camden, NJ (United States)

    2004-07-01

    Methane can be produced from the anaerobic digestion of waste. The methane can then be used to generate electricity or heat. However, anaerobic digester biogas contains hydrogen sulfide which can damage furnaces and other equipment. Several chemical and biological treatments have been developed to remove hydrogen sulfide from biogas. The physico-chemical processes include caustic scrubbing and adsorption, but both require large quantities of costly chemicals. This paper described the biological scrubber process which removes hydrogen sulfide from biogas produced by anaerobic digestion systems. Bacteria is used instead of chemicals to remove hydrogen sulfide. The biochemical reaction that occurs by sulfur-oxidizing microorganisms was described along with the methodology used in a full-scale biological scrubber installation at a paper mill's wastewater treatment facility. The main operating parameters for startup were biogas flow rate, hydrogen sulfide load, and pH. The biological scrubbers performed above the warranty standard of 97 per cent hydrogen sulfide removal. 1 tab.

  19. Microbial community changes in biological phosphate-removal systems on altering sludge phosphorus content

    NARCIS (Netherlands)

    Liu, WT; Linning, KD; Nakamura, K; Mino, T; Matsuo, T; Forney, LJ

    2000-01-01

    Biomarkers (respiratory quinones and cellular fatty acids) and denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes were used to characterize the microbial community structure of lab-scale enhanced biological phosphate-removal (EBPR) systems in response to altering sludge p

  20. Recent developments in the biochemistry and ecology of enhanced biological phosphorus removal

    NARCIS (Netherlands)

    Kortstee, GJJ; Appeldoorn, KJ; Bonting, CFC; van Niel, EWJ; van Veen, HW

    2000-01-01

    Most of the genes encoding the enzymes involved in polyP synthesis and degradation and in phosphate transport have been studied in various Gram-negative bacteria. Progress has also been made in studying the biochemical mechanisms underlying the process of enhanced biological phosphorus removal (EBPR

  1. Economic Benefits of Advanced Control Strategies in Biological Nutrient Removal Systems

    DEFF Research Database (Denmark)

    Carstensen, J.; Nielsen, M.K.; Harremoës, Poul

    1994-01-01

    Advances in on-line monitoring of nutrient salt concentrations and computer technology has created a large potential for the implementation of advanced and complex control strategies in biological nutrient removal systems. The majority of wastewater treatment plants today are operated with very...

  2. Bioprocesses for removal of carbon dioxide and nitrogen oxide by microalgae for the utilization of gas generated during coal burning

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Michele Greque de; Costa, Jorge Alberto Vieira [Fundacao Universidade Federal do Rio Grande, Rio Grande (Brazil)

    2008-07-01

    The aim of this work was to study the removal of CO{sub 2} and NO by microalgae and to evaluate the kinetic characteristics of the cultures. Spirulina sp. showed {mu}{sub max} and X{sub max} (0.11 d{sup -1}, 1.11 g L{sup -1} d{sup -1}) when treated with CO{sub 2} and NaNO{sub 3}. The maximum CO{sub 2} removal was 22.97% for S. obliquus treated with KNO{sub 3} and atmospheric CO{sub 2}. The S. obliquus showed maximum NO removal (21.30%) when treated with NO and CO{sub 2}. Coupling the cultivation of these microalgae with the removal of CO{sub 2} and NO has the potential not only to reduce the costs of culture media but also to offset carbon and nitrogen emissions. 19 refs., 3 figs., 2 tabs.

  3. Enhanced Biological Phosphorus Removal with Pseudomonas putida GM6 from Activated Sludge

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The enhanced biological phosphorus removal (EBPR) method is widely adopted for phosphorus removal from wastewater, yet little is known about its microbiological and molecular mechanisms. Therefore, it is difficult to predict and control the deterioration of the EBPR process in a large-scale municipal sewage treatment plant. This study used a novel strain isolated in the laboratory, Pseudomonas putida GM6, which had a high phosphate accumulating ability and could recover rapidly from the deteriorated system and enhance the capability of phosphorus removal in activated sludge. Strain GM6 marked with gfp gene, which was called GMTR, was delivered into a bench-scale sequencing batch reactor (SBR)of low efficiency, to investigate the colonization of GMTR and removal of phosphorus. After 21 days, the proportion of GMTR in the total bacteria of the sludge reached 9.2%, whereas the phosphorus removal rate was 96%, with an effluent concentration of about 0.2 mg L-1. In the reactor with the addition of GMTR, phosphorus was removed quickly, in 1 h under anaerobic conditions, and in 2 h under aerobic conditions. These evidences were characteristic of EBPR processes.Field testing was conducted at a hospital sewage treatment facility with low phosphorus removal capability. Twentyone days after Pseudononas putida GM6 was added, effluent phosphorus concentration remained around 0.3 mg L-1,corresponding to a removal rate of 96.8%. It was therefore demonstrated that Pseudomonas putida GM6 could be used for a quick startup and enhancement of wastewater biological phosphorus removal, which provided a scientific basis for potential large-scale engineering application.

  4. Effects of idle time on biological phosphorus removal by sequencing batch reactors.

    Science.gov (United States)

    Gao, Dawen; Yin, Hang; Liu, Lin; Li, Xing; Liang, Hong

    2013-12-01

    Three identical sequencing batch reactors (SBRs) were operated to investigate the effects of various idle times on the biological phosphorus (P) removal. The idle times were set to 3 hr (R1), 10 hr (R2) and 17 hr (R3). The results showed that the idle time of a SBR had potential impact on biological phosphorus removal, especially when the influent phosphorus concentration increased. The phosphorus removal efficiencies of the R2 and R3 systems declined dramatically compared with the stable R1 system, and the P-release and P-uptake rates of the R3 system in particular decreased dramatically. The PCR-DGGE analysis showed that uncultured Pseudomonas sp. (GQ183242.1) and beta-Proteobacteria (AY823971) were the dominant phosphorus removal bacteria for the R1 and R2 systems, while uncultured gamma-Proteobacteria were the dominant phosphorus removal bacteria for the R3 system. Glycogen-accumulating organisms (GAOs), such as uncultured Sphingomonas sp. (AM889077), were found in the R2 and R3 systems. Overall, the R1 system was the most stable and exhibited the best phosphorus removal efficiency. It was found that although the idle time can be prolonged to allow the formation of intracellular polymers when the phosphorus concentration of the influent is low, systems with a long idle time can become unstable when the influent phosphorus concentration is increased. PMID:24649669

  5. Removal of disinfection by-products formation potential by biologically intensified process

    Institute of Scientific and Technical Information of China (English)

    AN Dong; LI Wei-guang; CUI Fu-yi; HE Xin; ZHANG Jin-song

    2005-01-01

    The removal of disinfection by-products formation potential(DBPFP) in artificially intensified biological activated carbon(IBAC) process which is developed on the basis of traditional ozone granular activated carbon was evaluated. By IBAC removals of 31% and 68% for THMFP and HAAFP were obtained respectively. Under identical conditions, the removals of the same substances were 4% and 32% respectively only by the granular activated carbon(GAC) process. Compared with GAC, the high removal rates of the two formed potential substances were due to the increasing of bioactivity of the media and the synergistic capabilities of biological degradation cooperating with activated carbon adsorption of organic compounds. A clear linear correlation ( R2 = 0.9562 and R2 = 0.9007) between DOC HAAFP removal rate and Empty Bed Contact Time(EBCT) of IBAC process was observed, while that between THMFP removal rate and EBCT of GAC was R2 = 0.9782. In addition certain linear correlations between THMFP, HAAFP and UV254 ( R2 = 0.855 and R2 = 0.7702) were found for the treated water. For IBAC process there are also more advantages such as long backwashing cycle time, low backwashing intensity and prolonging activated carbon lifetime and so on.

  6. Performance of a completely autotrophic nitrogen removal over nitrite process for treating wastewater with different substrates at ambient temperature

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Chang; Dong Li; Yuhai Liang; Zhuo Yang; Shaoming Cui; Tao Liu; Huiping Zeng

    2013-01-01

    The stability and parameters of a bio-ceramic filter for completely autotrophic nitrogen removal were investigated.The completely autotrophic nitrogen removal over nitrite (CANON) reactor was fed with different concentrations of ammonia (400,300,and 200 mg N/L) but constant influent ammonia load.The results showed that the CANON system can achieve good treatment performance at ambient temperature (15-23℃).The average removal rate and removal loading of NH4 +-N and TN was 83.90%,1.26 kg N/(m3.day),and 70.14%,1.09 kg N/(m3.day),respectively.Among the influencing factors like pH,dissolved oxygen and alkalinity,it was indicated that the pH was the key parameter of the performance of the CANON system.Observing the variation of pH would contribute to better control of the CANON system in an intuitive and fast way.Denaturing gradient gel electrophoresis analysis of microorganisms further revealed that there were some significant changes in the community structure of ammonium oxidizing bacteria,which had low diversity in different stages,while the species of anaerobic ammonium oxidizing (anammox) bacteria were fewer and the community composition was relatively stable.These observations showed that anaerobic ammonia oxidation was more stable than the aerobic ammonia oxidation,which could explain that why the CANON system maintained a good removal efficiency under the changing substrate conditions.

  7. Nitrogen removal from eutrophic water by floating-bed-grown water spinach (Ipomoea aquatica Forsk.) with ion implantation.

    Science.gov (United States)

    Li, Miao; Wu, Yue-Jin; Yu, Zeng-Liang; Sheng, Guo-Ping; Yu, Han-Qing

    2007-07-01

    The aim of this study was to investigate the use of water spinach (Ipomoea aquatica Forsk.) with N(+) ion-beam implantation for removal of nutrient species from eutrophic water. The mutated water spinach was grown on floating beds, and growth chambers were used to examine the growth of three cultivars of water spinach with ion implantation for 14 days in simulated eutrophic water at both high and low nitrogen levels. The specific weight growth rates of three cultivars of water spinach with ion implantation were significantly higher than the control, and their NO(3)-N and NH(4)-N removal efficiencies were also greater than those of the control. Furthermore, compared with the control, the nitrogen contents in the plant biomass with ion implantation were higher as well. PMID:17524443

  8. [Effect of High Ammonium on Nitrogen Removal in an Partial Nitritation-ANAMMOX Process with Reflux System].

    Science.gov (United States)

    Li, Xiang; Cui, Jian-hong; Yuan, Yan; Huang, Yong; Yuan, Yi; Liu, Xin

    2015-10-01

    The effect of influent ammonia on nitrogen transformation characteristics and microbial communities in partial nitrification-anaerobic ammonia oxidation (PN-ANAMMOX) process was studied by using a series of partial nitrification and ANAMMOX process with air-lift reflux device. The results showed that when the influent ammonia concentration was increased to 700 mg x L(-1) and the nitrogen volume load was stabled at 2.8 kg x (m3 x d)(-1), the fluctuation of pH value was very small in aerobic and anaerobic zone. In the aerobic and anaerobic zone, FA concentrations were maintained at 5'mg x L(-1), 10 mg x L(-1), respectively, which did not inhibit the growth of microorganisms. Nitrite produce rate was stabled at 1.5 kg x (m3 x d)(-1) in the aerobic zone, and nitrogen removal rate was stabled at 31.49 kg x (m3 x d)(-1) in anaerobic zone, the total nitrogen removal rate was stabled at 1.67 kg x (m3 x d)(-1) in combined process. When the influent ammonia concentration was increased to 900 mg x L(-1), the FA and FNA concentration were increased in each areas, total nitrogen removal rate was decreased and stabled at 1.52 kg x- ( m3x- d( 1)'. The nitrite was accumulated in the anaerobic zone, and there was no significant inhibition of ANAMMOX bacteria. Our findings indicated that the reflux can effectively alleviate the fluctuation of pH in each area, and dilute FA concentration which is toxic to microorganisms. PMID:26841608

  9. Oxygen demand, nitrogen and copper removal by free-water-surface and subsurface-flow constructed wetlands under tropical conditions.

    Science.gov (United States)

    Lim, P E; Wong, T F; Lim, D V

    2001-05-01

    This study was conducted to: (1) assess the role of wetland vegetation in the removal of oxygen demand and nitrogen under tropical conditions, (2) estimate the uptake of nitrogen and copper by wetland plants and (3) investigate the speciation of Cu in wetland media among four operationally defined host fractions, namely exchangeable, carbonate, reducible and organically bound. Four laboratory-scale wetland units, two free-water-surface (FWS) and two subsurface-flow (SF) with one of each planted with cattails (Typha augustifolia), were fed with primary-treated sewage and operated at nominal retention times of 0.6-7 days. The influent and effluent BOD/COD and nitrogen concentrations were monitored to assess the performance of the wetland units for various mass loading rates. At the end of the study, all cattail plants were harvested and analyzed for total Kjeldahl nitrogen (TKN). Four other wetland units, which were identical to the first four, were fed with domestic wastewater spiked with copper in increasing concentrations. Copper speciation patterns in the sand layer were determined at the end of the study. The results showed that wetland vegetation did not play an important role in oxygen demand removal but were capable of removing about 22% and 26% of the nitrogen input in the FWS and SF wetland units, respectively. Mass balance analysis indicated that less than 1% of copper introduced was taken up by the cattails. Copper speciation patterns in the sand media showed that the exchangeable fraction contributed 30-57% and 63-80% of the nonresidual copper in the planted and unplanted FWS wetlands, respectively. For SF units, the percentages were 52-62% and 59-67%, respectively. This indicates that large amount of copper in the media were potentially remobilizable. PMID:11392762

  10. Removing undesirable color and boosting biological activity in red beet extracts using gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Sik; Lee, Eun Mi; Hong, Sung Hyun; Bai, Hyoung Woo; Chung, Byung Yeoup [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, In Chul [Youngdong University, Youngdong (Korea, Republic of)

    2011-10-15

    Red beet (Beta vulgaris L.) is a traditional and popular vegetable distributed in many part of the world and has been used as a natural colorant in many dairy products, beverages, candies and cattle products. Red beet roots contain two groups of betalain pigments, redviolet betacyanins and yellow betaxanthins. Betalains possess several biological activities such as antioxidant, anti-inflammatory, hepatoprotective, and anticancer properities. Recent trend of using natural products in industries tends toward multifunctional, high quality, and highpriced value foods and cosmetics. To meet the needs of consumers, cosmetics, medicine, and foods should contain the proper amount of natural products. Although the color removal processes such as filtration and absorption by clay are still useful, these procedures are difficult, time-consuming and costly. To overcome this problem, the radiation technology has emerged as a new way. Radiation technology has been applied to the decomposition and decoloration of pigment and is an efficient technique for inactivating pathogens, removing undesirable color in biomaterial extracts and improving or maintaining biological activities. Gamma-irradiation and electron beamirradiation techniques in previous reports were applied in order to remove any undesirable color and to improve or maintain biological activities of various extracts such as green tea leaves, licorice root, and S. chinensis fruits. Latorre et al. reported that betacyanin concentration decreased with the irradiation dose and significantly, in 35%, after 2.0 kGy of gamma-ray, whereas betaxathin concentration increased (about 11%-ratio with respect to control) after 1 kGy but decreased (about 19%) after 2 kGy. However, they did not try to analysis for completed removal of red beet pigments. Therefore, it is necessary to find the optimum irradiation dose for entirely removing red pigments in red beet. The aim of this work was to address the effects of the color removal and

  11. Removing undesirable color and boosting biological activity in red beet extracts using gamma irradiation

    International Nuclear Information System (INIS)

    Red beet (Beta vulgaris L.) is a traditional and popular vegetable distributed in many part of the world and has been used as a natural colorant in many dairy products, beverages, candies and cattle products. Red beet roots contain two groups of betalain pigments, redviolet betacyanins and yellow betaxanthins. Betalains possess several biological activities such as antioxidant, anti-inflammatory, hepatoprotective, and anticancer properities. Recent trend of using natural products in industries tends toward multifunctional, high quality, and highpriced value foods and cosmetics. To meet the needs of consumers, cosmetics, medicine, and foods should contain the proper amount of natural products. Although the color removal processes such as filtration and absorption by clay are still useful, these procedures are difficult, time-consuming and costly. To overcome this problem, the radiation technology has emerged as a new way. Radiation technology has been applied to the decomposition and decoloration of pigment and is an efficient technique for inactivating pathogens, removing undesirable color in biomaterial extracts and improving or maintaining biological activities. Gamma-irradiation and electron beamirradiation techniques in previous reports were applied in order to remove any undesirable color and to improve or maintain biological activities of various extracts such as green tea leaves, licorice root, and S. chinensis fruits. Latorre et al. reported that betacyanin concentration decreased with the irradiation dose and significantly, in 35%, after 2.0 kGy of gamma-ray, whereas betaxathin concentration increased (about 11%-ratio with respect to control) after 1 kGy but decreased (about 19%) after 2 kGy. However, they did not try to analysis for completed removal of red beet pigments. Therefore, it is necessary to find the optimum irradiation dose for entirely removing red pigments in red beet. The aim of this work was to address the effects of the color removal and

  12. Removing Iron and Manganese Simultaneously from Ground Water Using One-stage Biological Filter

    Institute of Scientific and Technical Information of China (English)

    XUE Gang; GAO Pin; GONG Qing-jie

    2009-01-01

    A novel process for removing iron and manganese simultaneously in ground water, which consisted of simple aeration and one-stage filtration, was developed in this research. It was found that the biological process had much higher manganese removal efficiency than chemical contact oxidation process. At the same time, the optimal operation parameters of aeration and biological filtration such as DO concentration and pH after aeration, filtration rate before and after startup, filtration operation cycle and backwashing rate, etc., were also obtained by experiments. By analyzing water quafity in different positions of filter bed, it was found that the oxidation of Fe2+ in biological filter bed adapted to first-order reaction, whereas the oxidation of Mn2+ conformed to zero-order reaction, which could be explained by Michaelis-Menten enzyme reaction equation when substrate concentration was far more than bacteria amount.

  13. Towards a plant-wide Benchmark Simulation Model with simultaneous nitrogen and phosphorus removal wastewater treatment processes.

    OpenAIRE

    Flores-Alsina, Xavier; Ikumi, David; Batstone, Damien; Gernaey, Krist; Brouckaert, Chris; Ekama, George A.; Jeppsson, Ulf

    2012-01-01

    It is more than 10 years since the publication of the Benchmark Simulation Model No 1 (BSM1) manual (Copp, 2002). The main objective of BSM1 was creating a platform for benchmarking carbon and nitrogen removal strategies in activated sludge systems. The initial platform evolved into BSM1_LT and BSM2, which allowed the evaluation of monitoring and plant-wide control strategies, respectively. The fact that the BSM platforms have resulted in 300+ publications demonstrates the interest for the to...

  14. Nitrogen and Phosphorus Removal in the Recirculating Aquaculture System with Water Treatment Tank containing Baked Clay Beads and Chinese Cabbage

    OpenAIRE

    Aeknarin Thanakitpairin; Wiboonluk Pungrasmi; Sorawit Powtongsook

    2014-01-01

    This research aims to describe the nitrogen and phosphorus removal in Recirculating Aquaculture System (RAS) by crop plants biomass production. The 3 experiment systems consisted of 1 treatment (fish tank + baked clay beads + Chinese cabbage) and 2 controls as control-1 (fish tank only) and control-2 (fish tank + baked clay beads), were performed. With all experimental RAS, Nile tilapia (Oreochromis niloticus) was cultured at 2 kg/m3 density. The baked clay beads (8-16 mm in diameter) were fi...

  15. A New Developed Airlift Reactor Integrated Settling Process and Its Application for Simultaneous Nitrification and Denitrification Nitrogen Removal

    OpenAIRE

    Tao Zhang; Chaohai Wei

    2013-01-01

    This study presented the performance of simultaneous nitrification and denitrification (SND) process using a new developed hybrid airlift reactor which integrated the activated sludge reaction process in the airlift reactor and the sludge settling separation process in the clarifier. The proposed reactor was started up successfully after 76 days within which the COD and total nitrogen removal rate can reach over 90% and 76.3%, respectively. The effects of different COD/N and DO concentrations...

  16. Removal of nitrogen and phosphorus from the secondary effluent in tertiary denitrifying biofilters combined with micro-coagulation.

    Science.gov (United States)

    Wei, Nan; Shi, Yunhong; Wu, Guangxue; Hu, Hongying; Guo, Yumei; Wu, Yihui; Wen, Hui

    2016-01-01

    Effective control of nitrogen and phosphorus in secondary effluent can reduce or avoid the eutrophication of receiving water bodies. Two denitrifying biofilters (DNBFs) packed with different sizes of quartz sands combined with micro-coagulation were operated for simultaneous removal of nitrogen and phosphorus from the secondary effluent. The quartz sand size in one DNBF was 2-4 mm (DNBFS), and in the other was 4-6 mm (DNBFL). In both DNBFs, methanol was used as the electron donor and different organic carbon to nitrogen (C/N) ratios were applied. Under C/N ratios of 1.5, 1.25, and 0.75 g/g, the nitrate nitrogen (NO3(-)-N) removal percentages were 73%, 77%, and 50% in DNBFS, and 43%, 25%, and 21% in DNBFL; the effluent total phosphorus concentrations were 0.15, 0.14, and 0.18 mg/L in DNBFS, and 0.29, 0.35, and 0.24 mg/L in DNBFL. The performance of both biofilters was quite stable within a backwashing cycle. The NO3(-)-N reduction rates were 1.31, 1.10, and 0.48 mg/(L·min) in DNBFS, and 0.97, 0.27, and 0.10 mg/(L·min) in DNBFL. For biomass detached from both biofilters, their denitrifying activities were similar. Biofilm biomass in DNBFS was higher than that in DNBFL, inducing a high denitrification efficiency in DNBFS. PMID:27232413

  17. Achieving complete nitrogen removal by coupling nitritation-anammox and methane-dependent denitrification: A model-based study.

    Science.gov (United States)

    Chen, Xueming; Guo, Jianhua; Xie, Guo-Jun; Yuan, Zhiguo; Ni, Bing-Jie

    2016-05-01

    The discovery of denitrifying anaerobic methane oxidation (DAMO) processes enables the complete nitrogen removal from wastewater by utilizing the methane produced on site from anaerobic digesters. This model-based study investigated the mechanisms and operational window for efficient nitrogen removal by coupling nitritation-anaerobic ammonium oxidation (Anammox) and methane-dependent denitrification in membrane biofilm reactors (MBfRs). A mathematical model was applied to describe the microbial interactions among Anammox bacteria, DAMO archaea, and DAMO bacteria. The model sufficiently described the batch experimental data from an MBfR containing an Anammox-DAMO biofilm with different feeding nitrogen compositions, which confirmed the validity of the model. The effects of process parameters on the system performance and microbial community structure could therefore be reliably evaluated. The impacts of nitritation produced NO2 (-) /NH4 (+) ratio, methane supply, biofilm thickness and total nitrogen (TN) surface loading were comprehensively investigated with the model. Results showed that the optimum NO2 (-) /NH4 (+) ratio produced from nitritation for the Anammox-DAMO biofilm system was around 1.0 in order to achieve the maximum TN removal (over 99.0%), independent on TN surface loading. The corresponding optimal methane supply increased while the associated methane utilization efficiency decreased with the increase of TN surface loading. The cooperation between DAMO organisms and Anammox bacteria played the key role in the TN removal. Based on these results, the proof-of-concept feasibility of a single-stage MBfR coupling nitritation-Anammox-DAMO for complete nitrogen removal was also tested through integrating the model with ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) processes whilst controlling the dissolved oxygen (DO) concentration in the simulated system. The maximum TN removal was found to be achieved at the bulk DO concentration

  18. Effect of inoculum and sulfide type on simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine slurry and microbial mechanism.

    Science.gov (United States)

    Wang, Lan; Wei, Benping; Chen, Ziai; Deng, Liangwei; Song, Li; Wang, Shuang; Zheng, Dan; Liu, Yi; Pu, Xiaodong; Zhang, Yunhong

    2015-12-01

    Four reactors were initiated to study the effect of inoculum and sulfide type on the simultaneous hydrogen sulfide removal from biogas and nitrogen removal from swine slurry (Ssu-Nir) process. Anaerobic sludge, aerobic sludge, and water were used as inocula, and Na2S and biogas were used as a sulfide substrate, respectively. Additionally, 454 pyrosequencing of the 16S rRNA gene was used to explore the bacterial diversity. The results showed that sulfur-oxidizing bacteria (Thiobacillus, 42.2-84.4 %) were dominant in Ssu-Nir process and led to the excellent performance. Aerobic sludge was more suitable for inoculation of the Ssu-Nir process because it is better for rapidly enriching dominant sulfur-oxidizing bacteria (Thiobacillus, 54.4 %), denitrifying sulfur-oxidizing bacteria (40.0 %) and denitrifiers (23.9 %). Lower S(2-) removal efficiency (72.6 %) and NO3 (-) removal efficiency (bacteria, Thiobacillus (84.8 %) and Thiobacillus sayanicus (39.6 %), which in turn led to low relative abundance of denitrifiers (1.6 %) and denitrifying sulfur-oxidizing bacteria (24.4 %), low NO3 (-) removal efficiency, and eventually poor performance. PMID:26286512

  19. Biological nitrogen fixation in common bean and faba bean using N-15 methodology and two reference crops

    International Nuclear Information System (INIS)

    A field was conducted on a Typic ustropepts soil located at 'La Tola', the experimental campus of the Agricultural Sciences Faculty at Tumbaco, Ecuador. The objectives were to quantify faba bean (Vicia faba) and common bean (Phaseolus vulgaris) biological nitrogen fixation, using quinoa (chenopodium quinoa) and maize (Zea mays) as reference crops. The average values were 80 and 70 per cent for faba bean and 42 and 14 per cent for common bean, respectively. It was assumed that nitrogen use eficiency was the same for fixing crops but observed that a crop with high nitrogen use efficiency overestimates legume biological nitrogen fixation. Results suggests that greater caution is needed when selecting reference crops for legumes with nitrogen fixation

  20. Evaluation of ion exchange resins for the removal of dissolved organic matter from biologically treated paper mill effluent.

    Science.gov (United States)

    Bassandeh, Mojgan; Antony, Alice; Le-Clech, Pierre; Richardson, Desmond; Leslie, Greg

    2013-01-01

    In this study, the efficiency of six ion exchange resins to reduce the dissolved organic matter (DOM) from a biologically treated newsprint mill effluent was evaluated and the dominant removal mechanism of residual organics was established using advanced organic characterisations techniques. Among the resins screened, TAN1 possessed favourable Freundlich parameters, high resin capacity and solute affinity, closely followed by Marathon MSA and Marathon WBA. The removal efficiency of colour and lignin residuals was generally good for the anion exchange resins, greater than 50% and 75% respectively. In terms of the DOM fractions removal measured through liquid chromatography-organic carbon and nitrogen detector (LC-OCND), the resins mainly targeted the removal of humic and fulvic acids of molecular weight ranging between 500 and 1000 g mol(-1), the portion expected to contribute the most to the aromaticity of the effluent. For the anion exchange resins, physical adsorption operated along with ion exchange mechanism assisting to remove neutral and transphilic acid fractions of DOM. The column studies confirmed TAN1 being the best of those screened, exhibited the longest mass transfer zone and maximum treatable volume of effluent. The treatable effluent volume with 50% reduction in dissolved organic carbon (DOC) was 4.8 L for TAN1 followed by Marathon MSA - 3.6L, Marathon 11 - 2.0 L, 21K-XLT - 1.5 L and Marathon WBA - 1.2 L. The cation exchange resin G26 was not effective in DOM removal as the maximum DOC removal obtained was only 27%. The resin capacity could not be completely restored for any of the resins; however, a maximum restoration up to 74% and 93% was achieved for TAN1 and Marathon WBA resins. While this feasibility study indicates the potential option of using ion exchange resins for the reclamation of paper mill effluent, the need for improving the regeneration protocols to restore the resin efficiency is also identified. Similarly, care should be taken