WorldWideScience

Sample records for batch reactor quarterly

  1. 40 CFR 63.1406 - Reactor batch process vent provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Reactor batch process vent provisions... § 63.1406 Reactor batch process vent provisions. (a) Emission standards. Owners or operators of reactor... reactor batch process vent located at a new affected source shall control organic HAP emissions...

  2. A Semi-Batch Reactor Experiment for the Undergraduate Laboratory

    Science.gov (United States)

    Derevjanik, Mario; Badri, Solmaz; Barat, Robert

    2011-01-01

    This experiment and analysis offer an economic yet challenging semi-batch reactor experience. Household bleach is pumped at a controlled rate into a batch reactor containing pharmaceutical hydrogen peroxide solution. Batch temperature, product molecular oxygen, and the overall change in solution conductivity are metered. The reactor simulation…

  3. Dynamic Simulation of Batch Photocatalytic Reactor (BPR) for Wastewater Treatment

    Science.gov (United States)

    Dutta, Suman

    2012-08-01

    Reactive dyes discharged from dyehouse causes a serious environmental problem. UV/TiO2 photocatalysis has been employed effectively for these organic dyes removal from dye-house effluent. This process produces less amount of non-toxic final product. In this paper a photocatalytic reactor has been designed for Reactive red 198 (RR198) removal from aqueous solution. The reactor is operating in batch mode. After each batch, TiO2 catalyst has been separated and recycled in the next batch. Mathematical model equation of this batch photocatalytic reactor (BPR) has been developed considering Langmuir-Hinshelwood kinetics. Simulation of BPR has been carried out using fourth order Runge-Kutta (RK) method and fifth order RK method (Butcher method). This simulation results can be used to develop an automatic photocatlytic reactor for industrial wastewater treatment. Catalyst activity decay and its effect on each batch have been incorporated in this model.

  4. Biodenitrification in Sequencing Batch Reactors. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Silverstein, J. [Colorado Univ., Boulder, CO (United States). Dept. of Civil, Environmental, and Architectural Engineering

    1996-01-23

    One plan for stabilization of the Solar Pond waters and sludges at Rocky Flats Plant (RFP), is evaporation and cement solidification of the salts to stabilize heavy metals and radionuclides for land disposal as low-level mixed waste. It has been reported that nitrate (NO{sub 3}{sub {minus}}) salts may interfere with cement stabilization of heavy metals and radionuclides. Therefore, biological nitrate removal (denitrification) may be an important pretreatment for the Solar Pond wastewaters at RFP, improving the stability of the cement final waste form, reducing the requirement for cement (or pozzolan) additives and reducing the volume of cemented low-level mixed waste requiring ultimate disposal. A laboratory investigation of the performance of the Sequencing Batch Reactor (SBR) activated sludge process developed for nitrate removal from a synthetic brine typical of the high-nitrate and high-salinity wastewaters in the Solar Ponds at Rocky Flats Plant was carried out at the Environmental Engineering labs at the University of Colorado, Boulder, between May 1, 1994 and October 1, 1995.

  5. Biodenitrification in Sequencing Batch Reactors. Final report

    International Nuclear Information System (INIS)

    One plan for stabilization of the Solar Pond waters and sludges at Rocky Flats Plant (RFP), is evaporation and cement solidification of the salts to stabilize heavy metals and radionuclides for land disposal as low-level mixed waste. It has been reported that nitrate (NO3-) salts may interfere with cement stabilization of heavy metals and radionuclides. Therefore, biological nitrate removal (denitrification) may be an important pretreatment for the Solar Pond wastewaters at RFP, improving the stability of the cement final waste form, reducing the requirement for cement (or pozzolan) additives and reducing the volume of cemented low-level mixed waste requiring ultimate disposal. A laboratory investigation of the performance of the Sequencing Batch Reactor (SBR) activated sludge process developed for nitrate removal from a synthetic brine typical of the high-nitrate and high-salinity wastewaters in the Solar Ponds at Rocky Flats Plant was carried out at the Environmental Engineering labs at the University of Colorado, Boulder, between May 1, 1994 and October 1, 1995

  6. APPLICATION OF MODEL PREDICTIVE CONTROL TO BATCH POLYMERIZATION REACTOR

    OpenAIRE

    N.M. Ghasem; Hussain, M. A.; S. A. Sata

    2006-01-01

    The absence of a stable operational state in polymerization reactors that operates in batches is factor that determine the need of a special control system. In this study, advanced control methodology is implemented for controlling the operation of a batch polymerization reactor for polystyrene production utilizingmodel predictive control. By utilizing a model of the polymerization process, the necessary operational conditions were determined for producing the polymer within the desired chara...

  7. Fault Diagnosis of Batch Reactor Using Machine Learning Methods

    OpenAIRE

    2014-01-01

    Fault diagnosis of a batch reactor gives the early detection of fault and minimizes the risk of thermal runaway. It provides superior performance and helps to improve safety and consistency. It has become more vital in this technical era. In this paper, support vector machine (SVM) is used to estimate the heat release (Qr) of the batch reactor both normal and faulty conditions. The signature of the residual, which is obtained from the difference between nominal and estimated faulty Qr values,...

  8. Biological Treatment of Dairy Wastewater by Sequencing Batch Reactor

    OpenAIRE

    A Mohseni-Bandpi, H Bazari

    2004-01-01

    A bench scale aerobic Sequencing Batch Reactor (SBR) was investigated to treat the wastewater from an industrial milk factory. The reactor was constructed from plexi glass material and its volume was 22.5 L. The reactor was supplied with oxygen by fine bubble air diffuser. The reactor was fed with milk factory and synthetic wastewater under different operational conditions. The COD removal efficiency was achieved more than 90%, whereas COD concentration varied from 400 to 2500 mg/l. The optim...

  9. APPLICATION OF MODEL PREDICTIVE CONTROL TO BATCH POLYMERIZATION REACTOR

    Directory of Open Access Journals (Sweden)

    N.M. Ghasem

    2006-06-01

    Full Text Available The absence of a stable operational state in polymerization reactors that operates in batches is factor that determine the need of a special control system. In this study, advanced control methodology is implemented for controlling the operation of a batch polymerization reactor for polystyrene production utilizingmodel predictive control. By utilizing a model of the polymerization process, the necessary operational conditions were determined for producing the polymer within the desired characteristics. The maincontrol objective is to bring the reactor temperature to its target temperature as rapidly as possible with minimal temperature overshoot. Control performance for the proposed method is encouraging. It has been observed that temperature overshoot can be minimized by the proposed method with the use of both reactor and jacket energy balance for reactor temperature control.

  10. Deposition of TiN films in a batch reactor

    OpenAIRE

    Hasper, Albert; Snijders, Gert-Jan; Vandezande, Lieve; De Blank, Marinus J.; Bankras, Radko Gerard

    2006-01-01

    Titanium nitride (TiN) films are formed in a batch reactor using titanium chloride (TiCl4) and ammonia (NH3) as precursors. The TiCl4 is flowed into the reactor in temporally separated pulses. The NH3 can also be flowed into the reactor in temporally spaced pulses which alternate with the TiCl4 pulses, or the NH3 can be flowed continuously into the reactor while the TiCl4 is introduced in pulses. The resulting TiN films exhibit low resistivity and good uniformity.

  11. Biological Treatment of Dairy Wastewater by Sequencing Batch Reactor

    Directory of Open Access Journals (Sweden)

    A Mohseni-Bandpi, H Bazari

    2004-10-01

    Full Text Available A bench scale aerobic Sequencing Batch Reactor (SBR was investigated to treat the wastewater from an industrial milk factory. The reactor was constructed from plexi glass material and its volume was 22.5 L. The reactor was supplied with oxygen by fine bubble air diffuser. The reactor was fed with milk factory and synthetic wastewater under different operational conditions. The COD removal efficiency was achieved more than 90%, whereas COD concentration varied from 400 to 2500 mg/l. The optimum dissolved oxygen in the reactor was 2 to 3 mg/l and MLVSS was around 3000 mg/l. Easy operation, low cost and minimal sludge bulking condition make the SBR system an interesting option for the biological medium strength industrial wastewater treatment. The study demonstrated the capability of aerobic SBR for COD removal from dairy industrial wastewater.

  12. A design algorithm for batch stirred tank transesterification reactors

    International Nuclear Information System (INIS)

    Highlights: ► Simplified algorithm for batch biodiesel reactor design was developed. ► C Sharp software tool for implementing the algorithm was also developed. ► 50 L/batch reactor was constructed and used to process neem oil biodiesel. ► Results showed that the produced neem biodiesel is a fuel grade product. ► Scale-up of the reactor was carried out using the developed software. - Abstract: A 50 L per batch, stirred tank reactor, suitable for carrying out transesterification of vegetable oils was designed and constructed. The major design assumptions included stainless steel plate thickness of 2 mm, reaction temperature of 60–65 °C and an initial/final fluid temperature of 25/70 °C. The calculated impeller Reynolds number was in the mixed regime zone of 10–104; the power number was varied between 1 and 5, while a typical propeller speed of 22.5 rev/s (or 1350 rev/min) was adopted. The limiting design conditions were maximum reactor diameter of 1.80 m, straight side height-to-diameter ratio in the range of 0.75–1.5 and minimum agitator motor power of 746 W (1 Hp). Based upon the design, a simple algorithm was developed and interpreted into Microsoft C Sharp computer programming language to enable scale up of the reactor. Performance testing of the realized reactor was carried out while using it to produce Neem oil biodiesel via base – catalyzed methanolysis, which yielded high quality fuel product.

  13. 40 CFR 63.1407 - Non-reactor batch process vent provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Non-reactor batch process vent... § 63.1407 Non-reactor batch process vent provisions. (a) Emission standards. (1) Owners or operators of non-reactor batch process vents located at new or existing affected sources with 0.25 tons per year...

  14. Industrial and Municipal Wastewater Treatment in the Sequencing Batch Reactor

    OpenAIRE

    Vrtovsek, J.; Ros, M.

    2008-01-01

    A mixture of Industrial wastewater from chemical industry (varnish, paint and pigments production) and municipal wastewater was treated in pilot sequencing batch reactor (SBR). Results of the pilot experiments show that the foaming problem has great influence on the behavior of SBR, especially when the ratio between industrial and municipal wastewater is very high. Foaming problem was negligible when the mixture with φ; 20 % of the industrial wastewater and j = 80 % of the municipal wastewate...

  15. SEQUENCING BATCH REACTOR: A PROMISING TECHNOLOGY IN WASTEWATER TREATMENT

    OpenAIRE

    A.H Mahvi

    2008-01-01

    Discharge of domestic and industrial wastewater to surface or groundwater is very dangerous to the environment. Therefore treatment of any kind of wastewater to produce effluent with good quality is necessary. In this regard choosing an effective treatment system is important. Sequencing batch reactor is a modification of activated sludge process which has been successfully used to treat municipal and industrial wastewater. The process could be applied for nutrients removal, high biochemical ...

  16. EFFECT OF DYE CONCENTRATION ON SEQUENCING BATCH REACTOR PERFORMANCE

    OpenAIRE

    A. A. Vaigan ، M. R. Alavi Moghaddam ، H. Hashemi

    2009-01-01

    Reactive dyes have been identified as problematic compounds in textile industries wastewater as they are water soluble and cannot be easily removed by conventional aerobic biological treatment systems. The treatability of a reactive dye (Brill Blue KN-R) by sequencing batch reactor and the influence of the dye concentration on system performance were investigated in this study. Brill Blue KN-R is one of the main dyes that are used in textile industries in Iran. Four cylindrical Plexiglas reac...

  17. Optimal parametric sensitivity control for a fed-batch reactor

    OpenAIRE

    Stigter, J.D.; Keesman, K. J.

    2001-01-01

    The paper presents a method to derive an optimal parametric sensitivity controller for optimal estimation of a set of parameters in an experiment. The method is demonstrated for a fed batch bio-reactor case study for optimal estimation of the saturation constant Ks and, albeit intuitively, the parameter combination "mu-max X/Y" where mu-max is the maximum growth rate [g/min], Y is the yield coefficient [g/g], and X is the (constant) biomass [g].

  18. Fault Diagnosis of Batch Reactor Using Machine Learning Methods

    Directory of Open Access Journals (Sweden)

    Sujatha Subramanian

    2014-01-01

    Full Text Available Fault diagnosis of a batch reactor gives the early detection of fault and minimizes the risk of thermal runaway. It provides superior performance and helps to improve safety and consistency. It has become more vital in this technical era. In this paper, support vector machine (SVM is used to estimate the heat release (Qr of the batch reactor both normal and faulty conditions. The signature of the residual, which is obtained from the difference between nominal and estimated faulty Qr values, characterizes the different natures of faults occurring in the batch reactor. Appropriate statistical and geometric features are extracted from the residual signature and the total numbers of features are reduced using SVM attribute selection filter and principle component analysis (PCA techniques. artificial neural network (ANN classifiers like multilayer perceptron (MLP, radial basis function (RBF, and Bayes net are used to classify the different types of faults from the reduced features. It is observed from the result of the comparative study that the proposed method for fault diagnosis with limited number of features extracted from only one estimated parameter (Qr shows that it is more efficient and fast for diagnosing the typical faults.

  19. Fast Reactor Programme. Third Quarter 1969. Progress Report

    International Nuclear Information System (INIS)

    The RCN research programme on fast spectrum nuclear reactors comprises reactor physics, fuel performance, radiation damage in canning materials, corrosion behaviour in canning materials, aerosol research and heat transfer and hydraulics. An overview is given of the fast reactor experiments at the STEK critical facility in Petten, the Netherlands, in the third quarter of 1969

  20. Modeling and Simulation of Thermal Transfer in Batch Reactor

    Directory of Open Access Journals (Sweden)

    Baghli, H.

    2006-01-01

    Full Text Available Batch reactors are frequently used in chemical, petrochemical or biochemical industry, for the production of various quality products. Processes used are discontinuous and varied. Indeed, they are characterized by non stationary and non linear systems. An optimal control of the process; requires a modeling and a simulation of the thermal behaviors inside the agitated jacketed reactor in view of the improvement of a high product quality and conditions of security. In certain fields, where the cost and the difficulty of tests are limiting factors, it is advantageous to develop the numeric simulations of these chemical processes. Thus, this study concerns the modeling and simulation of the thermal transfer in an agitated jacketed batch reactor, it is based on a model developed from the global energy balance and empiric correlations which give relationships between thermal transfer coefficients and the stirrer speed. We have achieved the validation of the model by confronting model results with several sets of experiences; for two types of stirrers.

  1. Treatemnt of Wastewater with Modified Sequencing Batch Biofilm Reactor Technology

    Institute of Scientific and Technical Information of China (English)

    胡龙兴; 刘宇陆

    2002-01-01

    This paper describes the removel of COD and nitrogen from wastewater with modified sequencing batch biofilm reactor,The strategy of simultaneous feeding and draining was explored.The results show that introduction of a new batch of wastewater and withdrawal of the purifeid water can be conducted simultaneously with the maximum volumetric exchange rate of about 70%,Application of this feeding and draining mode leads to the reduction of the cycle time,the increase of the utilization of the reactor volume and the simplification of the reactor structure.The treatment of a synthetic wastewater containing COD and nitrogen was investigated.The operation mode of F(D)-O(i.e.,simultaneous feeding and draining followed by the aerobic condition)was adopted.It was found that COD was degraded very fast in the initial reaction period of time,then reduced slowly and the ammonia nitrogen and nitrate nitrogen concentrations decreased and increased with time respectively,while the nitrite nitrogen level increased first and then reduced.The relationship between the COD or ammonia nitrogen loading and its removal rate was examined,and the removal of COD,ammonia nitrogen and total nitrogen could exceed 95%,90%and 80% respectively,The fact that nitrogen could e removed more completely under constant aeration(aerobic condition)of the SBBR operation mode is very interesting and could be explained in several respects.

  2. EFFECT OF DYE CONCENTRATION ON SEQUENCING BATCH REACTOR PERFORMANCE

    Directory of Open Access Journals (Sweden)

    A. A. Vaigan ، M. R. Alavi Moghaddam ، H. Hashemi

    2009-01-01

    Full Text Available Reactive dyes have been identified as problematic compounds in textile industries wastewater as they are water soluble and cannot be easily removed by conventional aerobic biological treatment systems. The treatability of a reactive dye (Brill Blue KN-R by sequencing batch reactor and the influence of the dye concentration on system performance were investigated in this study. Brill Blue KN-R is one of the main dyes that are used in textile industries in Iran. Four cylindrical Plexiglas reactors were run for 36 days (5 days for acclimatization of sludge and 31 days for normal operation at different initial dye concentrations. The dye concentrations were adjusted to be 20, 25, 30 and 40 mg/L in the reactors R1, R2, R3 and R4, respectively. In all reactors, effective volume, influent wastewater flowrate and sludge retention time were 5.5 L, 3.0 L/d and 10 d, respectively. According to the obtained data, average dye removal efficiencies of R1, R2, R3 and R4 were 57% ± 2, 50.18% ± 3, 44.97% ± 3 and 30.98% ± 3, respectively. The average COD removal efficiencies of all reactors were 97% ± 1, 97.12% ± 1, 96.93% ± 1 and 97.22% ± 1, respectively. The dye removal efficiency was decreased by increasing the dye concentration with the correlation coefficient of 0.997.

  3. Treatment of Laboratory Wastewater by Sequence Batch reactor technology

    International Nuclear Information System (INIS)

    These studies were conducted on the characterization and treatment of sewage mixed with waste -water of research and testing laboratory (PCSIR Laboratories Lahore). In this study all the parameters COD, BOD and TSS etc of influent (untreated waste-water) and effluent (treated waste-water) were characterized using the standard methods of examination for water and waste-water. All the results of the analyzed waste-water parameters were above the National Environmental Quality Standards (NEQS) set at National level. Treatment of waste-water was carried out by conventional sequencing batch reactor technique (SBR) using aeration and settling technique in the same treatment reactor at laboratory scale. The results of COD after treatment were reduced from (90-95 %), BOD (95-97 %) and TSS (96-99 %) and the reclaimed effluent quality was suitable for gardening purposes. (author)

  4. State estimation in a batch suspension polymerization reactor

    International Nuclear Information System (INIS)

    This paper concerns non-linear state estimation in a batch polymerization reactor where suspension polymerization of methyl methacrylate takes place. A kinetic model proposed in the literature is selected and its validity has been verified through an experimental set-up. Based on this model monomer conversion and average molecular weights of the polymer are estimated using only one output measurement (reactor temperature). The performance of the estimator, which has the structure of an extended Kalman filter, is examined through simulation and experimental studies in the presence of different levels of parameter uncertainties. The effects of adding fictitious noise and parameter state to the estimation algorithm are also investigated. To find the best fictitious state, the main parameters of polymerization model are divided into three groups. The parametric study of the MMA polymerization model indicates that, when the source of parameter uncertainty is unknown, the best selection of parameter state is the initial mass of monomer

  5. SEQUENCING BATCH REACTOR: A PROMISING TECHNOLOGY IN WASTEWATER TREATMENT

    Directory of Open Access Journals (Sweden)

    A. H. Mahvi

    2008-04-01

    Full Text Available Discharge of domestic and industrial wastewater to surface or groundwater is very dangerous to the environment. Therefore treatment of any kind of wastewater to produce effluent with good quality is necessary. In this regard choosing an effective treatment system is important. Sequencing batch reactor is a modification of activated sludge process which has been successfully used to treat municipal and industrial wastewater. The process could be applied for nutrients removal, high biochemical oxygen demand containing industrial wastewater, wastewater containing toxic materials such as cyanide, copper, chromium, lead and nickel, food industries effluents, landfill leachates and tannery wastewater. Of the process advantages are single-tank configuration, small foot print, easily expandable, simple operation and low capital costs. Many researches have been conducted on this treatment technology. The authors had been conducted some investigations on a modification of sequencing batch reactor. Their studies resulted in very high percentage removal of biochemical oxygen demand, chemical oxygen demand, total kjeldahl nitrogen, total nitrogen, total phosphorus and total suspended solids respectively. This paper reviews some of the published works in addition to experiences of the authors.

  6. Biological Treatment of Leachate using Sequencing Batch Reactor

    Directory of Open Access Journals (Sweden)

    WDMC Perera

    2014-12-01

    Full Text Available Normal 0 false false false EN-US X-NONE TA Abstract   In Sri Lanka municipal solid waste is generally disposed in poorly managed open dumps which lack liner systems and leachate collection systems. Rain water percolates through the waste layers to produce leachate which drains in to ground water and finally to nearby water bodies, degrading the quality of water. Leachate thus has become a major environmental concern in municipal waste management and treatment of leachate is a major challenge for the existing and proposed landfill sites.   The study was conducted to assess the feasibility of the usage of the Sequencing Batch Reactor in the treatment of the landfill leachate up to the proposed levels in the draft report of “Proposed Sri Lankan standard for landfill leachate to be disposed to the inland waters". Leachate collected from the open dumpsite at Meethotamulla, Western Province, Sri Lanka was used for leachate characterization.   SBR was constructed with a 10-liter working volume operated in an 18 hour cycle mode and each cycle consists of 15hours of aerobic, 2h settle and 0.5 h of fill/decant stages. The Dissolved Oxygen level within the SBR was maintained at 2 mg/l through the aerobic stage. Infeed was diluted with water during the acclimatization period and a leachate to water ratio of 55:45 was maintained. The removal efficiencies for different parameters were; COD (90.5%, BOD (92.6%, TS (92.1%, Conductivity (83.9%, Alkalinity (97.4%, Hardness (82.2%, Mg (80.5%, Fe (94.2%, Zn (63.4%, Cr (31.69%, Pb (99.6%, Sulphate (98.9%, and Phosphorus (71.4% respectively. In addition Ni and Cd were removed completely during a single SBR cycle. Thus the dilution of leachate in the dumpsites using municipal wastewater, groundwater or rainwater was identified as the most cost effective dilution methods. The effluent from the Sequencing batch reactor is proposed to be further treated using a constructed wetland before releasing to surface water.

  7. Degradation of formaldehyde in anaerobic sequencing batch biofilm reactor (ASBBR)

    International Nuclear Information System (INIS)

    The present study evaluated the degradation of formaldehyde in a bench-scale anaerobic sequencing batch reactor, which contained biomass immobilized in polyurethane foam matrices. The reactor was operated for 212 days at 35 deg. C with 8 h sequential cycles, under different affluent formaldehyde concentrations ranging from 31.6 to 1104.4 mg/L (formaldehyde loading rates from 0.08 to 2.78 kg/m3 day). The results indicate excellent reactor stability and over 99% efficiency in formaldehyde removal, with average effluent formaldehyde concentration of 3.6 ± 1.7 mg/L. Formaldehyde degradation rates increased from 204.9 to 698.3 mg/L h as the initial concentration of formaldehyde was increased from around 100 to around 1100 mg/L. However, accumulation of organic matter was observed in the effluent (chemical oxygen demand (COD) values above 500 mg/L) due to the presence of non-degraded organic acids, especially acetic and propionic acids. This observation poses an important question regarding the anaerobic route of formaldehyde degradation, which might differ substantially from that reported in the literature. The anaerobic degradation pathway can be associated with the formation of long-chain oligomers from formaldehyde. Such long- or short-chain polymers are probably the precursors of organic acid formation by means of acidogenic anaerobic microorganisms

  8. molecular weight control of a batch suspension polymerization reactor

    International Nuclear Information System (INIS)

    This paper concerns molecular weight control of a batch polymerization reactor where suspension polymerization of methyl methylacrylate (MMA) takes place. For this purpose, a cascade control structure with two control loops has been selected. The slave loop is used for temperature control using on-line temperature measurements, and the master loop controls the average molecular weights based on its estimated values. Two different control algorithms namely proportional-integral (PI) controller and globally linearizing controller (GLC) have been used for temperature control. An estimator, which has the structure of an extended Kalman filter(EKF), is used for estimating monomer conversion and average molecular weights of polymer using reactor temperature measurements. The performance of proposed control algorithm is evaluated through simulation and experimental studies. The results indicate that a constant average molecular weight cannot be achieved in case of strong gel effect. However, the polydispersity of product will be lower in comparison to isothermal operation. It is also shown that in case of mo dek mismatch, the performance of cascade control is superior compared to the case where only reactor temperature is controlled based on desired temperature trajectory obtained through cascade strategy

  9. CONVERTING FROM BATCH TO CONTINUOUS INTENSIFIED PROCESSING IN THE STT? REACTOR

    Science.gov (United States)

    The fluid dynamics, the physical dimensions and characteristics of the reaction zones of continuous process intensification reactors are often quite different from those of the batch reactors they replace. Understanding these differences is critical to the successful transit...

  10. Hydrolyzed polyacrylamide biodegradation and mechanism in sequencing batch biofilm reactor.

    Science.gov (United States)

    Yan, Miao; Zhao, Lanmei; Bao, Mutai; Lu, Jinren

    2016-05-01

    An investigation was performed to study the performance of a sequencing batch biofilm reactor (SBBR) to treat hydrolyzed polyacrylamides (HPAMs) and to determine the mechanisms of HPAM biodegradation. The mechanisms for the optimized parameters that significantly improved the degradation efficiency of the HPAMs were investigated by a synergistic effect of the co-metabolism in the sludge and the enzyme activities. The HPAM and TOC removal ratio reached 54.69% and 70.14%. A significant decrease in the total nitrogen concentration was measured. The carbon backbone of the HPAMs could be degraded after the separation of the amide group according to the data analysis. The HPLC results indicated that the HPAMs could be converted to polymer fragments without the generation of the acrylamide monomer intermediate. The results from high-throughput sequencing analysis revealed proteobacterias, bacteroidetes and planctomycetes were the key microorganisms involved in the degradation. PMID:26896716

  11. Pretreatment of coking wastewater using anaerobic sequencing batch reactor (ASBR)

    Institute of Scientific and Technical Information of China (English)

    LI Bing; SUN Ying-lan; LI Yu-ying

    2005-01-01

    A laboratory-scale anaerobic sequencing batch reactor (ASBR) was used to pretreat coking wastewater. Inoculated anaerobic granular biomass was acclimated for 225 d to the coking wastewater, and then the biochemical methane potential (BMP)of the coking wastewater in the acclimated granular biomass was measured. At the same time, some fundamental technological factors, such as the filling time and the reacting time ratio (tf/tr), the mixing intensity and the intermittent mixing mode, that affect anaerobic pretreatment of coking wastewater with ASBR, were evaluated through orthogonal tests. The COD removal efficiency reached 38%~50% in the stable operation period with the organic loading rate of 0.37~0.54 kg COD/(m3.d) at the optimum conditions of tf/tr, the mixing intensity and the intermittent mixing mode. In addition, the biodegradability of coking wastewater distinctly increased after the pretreatment using ASBR. At the end of the experiment, the microorganism forms on the granulated sludge in the ASBR were observed using SEM (scanning electron microscope) and fluoroscope. The results showed that the dominant microorganism on the granular sludge was Methanosaeta instead of Methanosarcina dominated on the inoculated sludge.

  12. Simultaneous denitrifying phosphorus accumulation in a sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    YUAN Linjiang; HAN Wei; WANG Lei; YANG Yongzhe; WANG Zhiying

    2007-01-01

    In order to achieve simultaneous nitrogen and phosphorus removal in the biological treatment process,denitrifying phosphorus accumulation(DNPA)and its affecting factors were studied in a sequencing batch reactor(SBR)with synthetic wastewater.The results showed that when acetate was used as the sole carbon resource in the influent.the sludge acclimatized under anaerobic/aerobic operation had good phosphorus removal ability.Denitrifying phosphorus accumulation was observed soon when fed with nitrate instead of aeration following the anaerobic stage,which is a vital premise to DNPA.If DNPA sludge is fed with nitrate prior to the anaerobic stage,the DNPA would weaken or even disappear.At the high concen tration of nitrate fed in the anoxic stage,the longer anoxic time needed,the better the DNPA was.Induced DNPA did not disappear even though an aerobic stage followed the anoxic stage,but the shorter the aerobic stage lasted,the higher the proportions of phosphorus removal via DNPA to total removal.

  13. 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.

  14. Batch and Pulsed Fed-Batch Cultures of Aspergillus flavipes FP-500 Growing on Lemon Peel at Stirred Tank Reactor.

    Science.gov (United States)

    Wolf-Márquez, V E; García-García, E; García-Rivero, M; Aguilar-Osorio, G; Martínez Trujillo, M A

    2015-11-01

    Aspergillus flavipes FP-500 grew up on submerged cultures using lemon peel as the only carbon source, developing several batch and pulsed fed-batch trials on a stirred tank reactor. The effect of carbon source concentration, reducing sugar presence and initial pH on exopectinase and endopectinase production, was analyzed on batch cultures. From this, we observed that the highest substrate concentration favored biomass (X max) but had not influence on the corresponding specific production (q p) of both pectinases; the most acid condition provoked higher endopectinase-specific productions but had not a significant effect on those corresponding to exopectinases; and reducing sugar concentrations higher than 1.5 g/L retarded pectinase production. On the other hand, by employing the pulsed fed-batch operation mode, we observed a prolonged growth phase, and an increase of about twofold on endopectinase production without a significant raise on biomass concentration. So, pulsed fed-batch seems to be a good alternative for obtaining higher endopectinase titers by using high lemon peel quantities without having mixing and repression problems to the system. The usefulness of unstructured kinetic models for explaining, under a theoretic level, the behavior of the fungus along the batch culture with regard to pectinase production was evident. PMID:26304128

  15. Photocatalytic reactors for treating water pollution with solar illumination. I: a simplified analysis for batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Sagawe, G.; Bahnemann, D. [Inst. fuer Technische Chemie, Univ. Hannover, Hannover (Germany); Brandi, R.J.; Cassano, A.E. [INTEC (Univ. Nacional del Litoral and CONICET), Santa Fe (Argentina)

    2003-07-01

    Usual applications of photocatalytic reactors for treating wastewater exhibit the difficulty of handling fluids having varying composition and/or concentrations; thus, a detailed kinetic representation may not be possible. When the catalyst activation is obtained employing solar illumination an additional complexity always coexists: solar fluxes are permanently changing with time. For comparing different reacting systems under similar operating conditions and to provide approximate estimations for scaling up purposes, simplified models may be useful. For these approximations the model parameters should be restricted as much as possible to initial physical and boundary conditions such as: initial concentrations (expressed as such or as TOC measurements), flow rate or reactor volume, irradiated reactor area, incident radiation fluxes and a fairly simple experimental observation such as the photonic efficiency. A combination of a new concept: the ''actual observed photonic efficiency'' with ideal reactor models and empirical kinetic rate expressions can be used to provide rather simple working equations that can be efficiently used to describe the performance of practical reactors. In this paper, the method has been developed for the case of a photocatalytic batch reactor (PBR). (orig.)

  16. Effect of nitrification on phosphorus dissolving in a piggery effluent treated by a sequencing batch reactor

    OpenAIRE

    Daumer, M.L.; Béline, F.; Guiziou, F.; Spérandio, M

    2007-01-01

    The effect of the nitrification on dissolved phosphorus during the treatment of piggery wastewater by a modified sequencing batch reactor has been observed in a previous study. The high solid mineral phosphorus content in the piggery wastewater and the chemical mechanism induced by the fall in pH during the nitrification were proposed to explain this effect. In this work, trials using modified sequencing batch reactors were performed to study the influence of the amount of nitrified nitrogen ...

  17. INVESTIGATION OF INTERMITTENT CHLORINATION SYSTEM IN BIOLOGICAL EXCESS SLUDGE REDUCTION BY SEQUENCING BATCH REACTORS

    OpenAIRE

    A. Takdastan ، N. Mehrdadi ، A. A. Azimi ، A. Torabian ، G. Nabi Bidhendi

    2009-01-01

    The excessive biological sludge production is one of the disadvantages of aerobic wastewater treatment processes such as sequencing batch reactors. To solve the problem of excess sludge production, oxidizing some of the sludge by chlorine, thus reducing the biomass coefficient as well as the sewage sludge disposal may be a suitable idea. In this study, two sequencing batch reactors, each with 20 L volume and controlled by on-line system were used. After providing the steady state conditions i...

  18. The functionalization of carbon nanotubes using a batch oscillatory flow reactor

    OpenAIRE

    Melendi, Sonia; Bonyadi, S; Castell, P.; Martinez, M.T.; Mackley, M.R.

    2012-01-01

    This paper describes an efficient method for the functionalizing of multi-walled carbon nanotubes (MWCNT) using oscillatory flow mixing (OFM). A 3. l batch oscillatory flow reactor (OFR) was designed and constructed for pilot scale functionalization of MWCNT in order to potentially improve their compatibility within a thermoplastic polyphenylene sulphide (PPS) matrix. The OFM batch reactor consisted of a jacketed cylindrical vessel with a vertical axial oscillator that contained a series of b...

  19. Reactor safety research programs. Quarterly progress report, January 1--March 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Romano, A.J. (comp.)

    1977-05-01

    The projects reported each quarter are the following: Gas Reactor Safety Evaluation, THOR Code Development, SSC Code Development, LMFBR and LWR Safety Experiments, Fast Reactor Safety Code Validation, Technical Coordination of Structural Integrity, and Fast Reactor Safety Reliability Assessment.

  20. Aerobic Granulation in Sequencing Batch Reactor (SBR Treating Saline Wastewater

    Directory of Open Access Journals (Sweden)

    Ensieh Taheri

    2012-04-01

    Full Text Available Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background and Objectives: Aerobic sludge granulation is an advanced phenomenonin which its mechanisms have not been understood. Granulation can be a promising and novel biological wastewater treatment technology to eliminate organic and inorganic materials in future. High salinity is a parameter which leads to plasmolisatian and reduction of the cell activity. This could be a problem for biological treatment of the saline wastewater. Aerobic granule was formed and investigated during this study. Materials and Methods: This study is an intervention study on the treatment of wastewater with 500-10000 mg/L concentration of NaCl by sequencing batch reactor. Asynthesized wastewater including nutrient required for microorganism's growth was prepared. Input and output pH and EC were measured. Range of pH and DO varied between 7-8, and 2-5 mg/L, respectively. SEM technology was used to identify graduals properties.Results: In terms of color, granules divided into two groups of light brown and black. Granule ranged in 3-7mm with the sediment velocity of 0.9-1.35 m/s and density of 32-60 g/L.Properties of granules were varied. Filamentous bacteria and fungi were dominant in some granules. However non filamentous bacteria were dominant in others. EDX analysis indicated the presence of Ca and PO4.Conclusion: Granules with non filamentous bacterial were compact and settled faster. Presence of different concentrations of salinity leaded to plasmolysis of the bacterial cells and increased concentrations of EPS  in the system as a result  of which granulation accelerated. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso

  1. Characteristics of anoxic phosphors removal in sequence batch reactor

    Institute of Scientific and Technical Information of China (English)

    WANG Ya-yi; PAN Mian-li; Yan Min; PENG Yong-zhen; WANG Shu-ying

    2007-01-01

    The characteristics of anaerobic phosphorus release and anoxic phosphorus uptake was investigated in sequencing batch reactors using denitrifying phosphorus removing bacteria (DPB) sludge. The lab-scale experiments were accomplished under conditions of various nitrite concentrations (5.5, 9.5, and 15 mg/L) and mixed liquor suspended solids (MLSS) (1844, 3231, and 6730 mg/L). The results obtained confirmed that nitrite, MLSS, and pH were key factors, which had a significant impact on anaerobic phosphorus release and anoxic phosphorus uptake in the biological phosphorous removal process. The nitrites were able to successfully act as electron acceptors for phosphorous uptake at a limited concentration between 5.5 and 9.5 mg/L. The denitrification and dephosphorous were inhibited when the nitrite concentration reached 15 mg/L. This observation indicated that the nitrite would not inhibit phosphorus uptake before it exceeded a threshold concentration. It was assumed that an increase of MLSS concentration from 1844 mg/L to 6730 mg/L led to the increase of denitrification and anoxic P-uptake rate. On the contrary, the average P uptake/N denitrifying reduced from 2.10 to 1.57 mg PO43--P/mg NO3--N. Therefore, it could be concluded that increasing MLSS of the DEPHANOX system might shorten the reaction time of phosphorus release and anoxic phosphorus uptake. However, excessive MLSS might reduce the specific denitrifying rate. Meanwhile, a rapid pH increase occurred at the beginning of the anoxic conditions as a result of denitrification and anoxic phosphate uptake. Anaerobic P release rate increased with an increase in pH. Moreover, when pH exceeded a relatively high value of 8.0, the dissolved P concentration decreased in the liquid phase, because of chemical precipitation. This observation suggested that pH should be strictly controlled below 8.0 to avoid chemical precipitation if the biological denitrifying phosphorus removal capability is to be studied accurately.

  2. Performance of anaerobic sequencing batch reactors (pilot-scale in domestic sewage treatment

    Directory of Open Access Journals (Sweden)

    Eugenio Foresti

    2005-02-01

    Full Text Available This study shows the results obtained during 70 days using four pilot scale anaerobic sequencing batch reactors, for sewage system treatment of the campus of the University of São Paulo in São Carlos – SP. Each reactor system with 1.2 m³ of total volume, was designed for the treatment of 1.95 m³d³ of domestic sewage, with geometrical conceptions (ratio H-height/D-diameter, mechanical conceptions (mechanical mixing or liquid re-circulation and different biomass retention type. Three of them were ASBR (AnaerobicSequencing Batch Reactor with granular biomass and another one was an ASBBR (Anaerobic Sequencing Batch Biofilm Reactor with biomass consisting of cubic matrices of polyurethane foam. The reactors were inoculated and operated within an 8-hour batch cycle. The reactors monitoring included the oxygen chemical demand (OCD, pH, total suspended solids (TSS and volatile suspended solids, volatile fatty acids, alkalinity to bicarbonate and methane concentration. Both ASBR reactors with liquid re-circulation did not show a satisfactory performance. The average values of OCD and TSS removal were close to 40% and 60% respectively. In the ASBR reactors with mechanical mixing and ASBBR with immobilized biomass, showed better results. The ASBBR reactor reached average efficiency of 61% and 75% in OCD and TSS removal, while in the ASBR with mechanical mixing, it reached 60% and 79%, respectively.

  3. Kinetics and Product Selectivity (Yield) of Second Order Competitive Consecutive Reactions in Fed-Batch Reactor and Plug Flow Reactor

    OpenAIRE

    Selvamony, Subash Chandra Bose

    2013-01-01

    This literature compares the performance of second order competitive consecutive reaction in Fed-Batch Reactor with that in continuous Plug Flow Reactor. In a kinetic sense, this simulation study aims to develop a case for continuous Plug Flow Reactor in pharmaceutical, fine chemical, and related other chemical industries. MATLAB is used to find solutions for the differential equations. The simulation results show that, for certain cases of nonelementary scenario, product selectivity is highe...

  4. Enhancement of a semi-batch chemical reactor efficiency through its dimensions optimization

    OpenAIRE

    Macků, Lubomír; Novosad, David

    2015-01-01

    Efficiency of manufacturing processes is very important in today's competitive world with hard economic rules. In chemical engineering area the efficiency depends on the production heart, which is often a chemical reactor. In this paper authors describe process of optimal semi-batch exothermic reactor dimensions finding. The task is to find reactor dimensions which lead to process efficiency improving, i.e. to processing the greater chemicals amount in the same or shorter time. The optimizing...

  5. Nitrification of industrial and domestic saline wastewaters in moving bed biofilm reactor and sequencing batch reactor

    International Nuclear Information System (INIS)

    Nitrification of saline wastewaters was investigated in bench-scale moving-bed biofilm reactors (MBBR). Wastewater from a chemical industry and domestic sewage, both treated by the activated sludge process, were fed to moving-bed reactors. The industrial wastewater contained 8000 mg Cl-/L and the salinity of the treated sewage was gradually increased until that level. Residual substances present in the treated industrial wastewater had a strong inhibitory effect on the nitrification process. Assays to determine inhibitory effects were performed with the industrial wastewater, which was submitted to ozonation and carbon adsorption pretreatments. The latter treatment was effective for dissolved organic carbon (DOC) removal and improved nitrification efficiency. Nitrification percentage of the treated domestic sewage was higher than 90% for all tested chloride concentrations up to 8000 mg/L. Results obtained in a sequencing batch reactor (SBR) were consistent with those attained in the MBBR systems, allowing tertiary nitrification and providing adequate conditions for adaptation of nitrifying microorganisms even under stressing and inhibitory conditions.

  6. Coexistence of nitrifying, anammox and denitrifying bacteria in a sequencing batch reactor

    OpenAIRE

    MichelaLangone; JiaYan

    2014-01-01

    Elevated nitrogen removal efficiencies from ammonium-rich wastewaters have been demonstrated by several applications, that combine nitritation and anammox processes. Denitrification will occur simultaneously when organic carbon is also present. In this study, the activity of aerobic ammonia oxidizing, anammox and denitrifying bacteria in a full scale Sequencing Batch Reactor, treating digester supernatants, was studied by means of batch-assays. AOB and anammox activities were maximum at pH of...

  7. Effect of long-term idle periods on the performance of sequencing batch reactors

    DEFF Research Database (Denmark)

    Morgenroth, Eberhard Friedrich; Obermayer, A.; Arnold, E.; Brühl, A.; Wagner, M.; Wilderer, P. A.

    2000-01-01

    Sludge storage can be used as an effective control handle to adjust plant capacity to large influent variations. The sequencing batch reactor (SBR) technology is well suited for temporary sludge storage because reactors can easily be switched off individually and operated in an idle mode. In this...... study experimental results on the effect of long term (weeks) idle periods on nitrogen removal are presented. The SBRs were operated with idle times ranging from 6 to 20 days. Batch experiments were performed where sludge was stored without the addition of any substrate for 7 weeks. In the SBRs...

  8. REMOVAL OF REACTIVE BLUE 19 BY ADDING POLYALUMINUM CHLORIDE TO SEQUENCING BATCH REACTOR SYSTEM

    OpenAIRE

    1Sh. Mehrali, *1M. R. Alavi Moghaddam, 2S. H. Hashemi

    2010-01-01

    The main objective of this study was to evaluate Reactive Blue 19 dye removal efficiency in aerobic sequencing batch reactor (SBR) process by adding polyaluminum chloride (PACl). PACl was added to the reactors in concentrations of 0, 1, 5, 15 and 30 mg-Al/L (SBR1 to SBR5) after filling periods. Initial dye concentrations were selected to be 40 mg/L for all reactors. The averages of dye removal efficiencies were more than 57% in all reactors. The maximum and minimum dye removal efficiencies we...

  9. Fast Reactor Programme. Second Quarter 1969. Progress Report. RCN Report

    International Nuclear Information System (INIS)

    This progress report covers fast reactor research carried out by RCN during the second quarter 1969 forming part of the integrated fast breeder research and development programme also in progress at the national nuclear research centres Karlsruhe and Mol. The combined effort is based on a memorandum of co-operation in this field signed by the respective governments in 1968 and on a memorandum of understanding signed by the research centres. The RCN contribution is mainly concerned with the core of the fast breeder reactor and related safety aspects and, as such, must be looked upon as being complementary to the industrial research pro- field of fast reactors. The contribution comprises the following six items: - A Æéatîtôr , physics programme to determine the influence of fission products on several main characteristics of the reactor core such as void coefficient, Doppler coefficient and breeding ratio; - A fuel performance programme in which both stationary and transient irradiations are being carried out to establish the temperature and power limits of fuel rods; also the consequences of loss- of-cooling will be investigated; - Investigation into the change in mechanical properties of fuel canning materials due to high fast neutron doses; - A study of the corrosion behaviour of canning materials and their compatibility with the fuel under conditions of high temperature and high pressure; - Investigation into the behaviour of aerosols of fission products which could be formed after a fast reactor accident; a thorough understanding is of utmost importance for the reactor safety assessment ; - Studies on heat transfer in the reactor core. As fast breeders operate at high power densities, an accurate knowledge on the heat transfer phenomena is required

  10. Batch Tests To Determine Activity Distribution and Kinetic Parameters for Acetate Utilization in Expanded-Bed Anaerobic Reactors

    OpenAIRE

    Fox, Peter; Suidan, Makram T.

    1990-01-01

    Batch tests to measure maximum acetate utilization rates were used to determine the distribution of acetate utilizers in expanded-bed sand and expanded-bed granular activated carbon (GAC) reactors. The reactors were fed a mixture of acetate and 3-ethylphenol, and they contained the same predominant aceticlastic methanogen, Methanothrix sp. Batch tests were performed both on the entire reactor contents and with media removed from the reactors. Results indicated that activity was evenly distrib...

  11. Effect of internal recirculation velocity in an anaerobic sequencing batch reactor (ASBR)

    OpenAIRE

    G. Z. Maurina; L. M. Rosa; L. L. Beal; C. Baldasso; J. R. Gimenez; Torres, A.P. (Asvin Pérez); M.P. Sousa

    2014-01-01

    This paper discusses the effect of different internal recirculation velocities on the mixture and shear stress on the flocs in an anaerobic sequencing batch reactor (ASBR). Thus, simulations are performed using a computational fluid dynamics (CFD) tool to evaluate this dependency. The analysis of velocities and turbulent kinetic energy indicates that the highest flow evaluated (0.003 m³/s) results in better mixing within the reactor. However, care must be taken with the recycling pipe size, i...

  12. Simulation of kefiran production of Lactobacillus kefiranofaciens JCM6985 in fed-batch reactor

    Directory of Open Access Journals (Sweden)

    Benjamas Cheirsilp

    2006-09-01

    Full Text Available Kinetics of kefiran production by Lactobacillus kefiranofaciens JCM6985 has been investigated. A mathematical model taking into account the mechanism of exopolysaccharides production has been developed. Experiments were carried out in batch mode in order to obtain kinetic model parameters that were further applied to simulate fed-batch processes. A simplification of parameter fitting was also introduced for complicated model. The fed-batch mode allows more flexibility in the control of the substrate concentration as well as product concentration in the culture medium. Based on the batch mathematical model, a fed-batch model was developed and simulations were done. Simulation study in fed-batch reactor resulted that substrate concentration should be controlled at 20 g L-1 to soften the product inhibition and also to stimulate utilization of substrate and its hydrolysate. From simulation results of different feeding techniques, it was found that constant feeding at 0.01 L h-1 was most practically effective feeding profile for exopolysaccharides production in fed-batch mode.

  13. Psychrophilic anaerobic digestion of swine manure slurry in sequencing batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Masse, D.I. [Agriculture Canada, Ottawa, ON (Canada). Food Research Branch; Droste, R.L. [Ottawa Univ., ON (Canada). Dept. of Civil Engineering

    1993-12-31

    This work presents preliminary results of an ongoing laboratory study to evaluate the feasibility of psychrophilic anaerobic digestion in sequencing batch reactors (SBR) for stabilizing, deodorizing and adding value to swine manure. Preliminary results show that the process is feasible. (author). 14 refs., 7 tabs.

  14. The Effects of Batch Reactor Extraction on Antioxidant Activity from Scurulla atropurpurea

    Directory of Open Access Journals (Sweden)

    Siti I. Rahmawati

    2012-01-01

    Full Text Available Problem statement: The main active compounds of benalu teh’s include alkaloids and flavonoids, therefore antioxidant of it has big potential to develop. In the context of extraction, the traditional (boiling in the water until one-third remain extraction require a long extraction time and result in low yields of extraction also antioxidant activities. Approach: Batch reactor is extraction at high temperature under applied pressure to keep the solvent under liquid phase, by this technology we hope to obtain better results. Optimum extraction conditions of benalu teh need to be discovered to obtain the antioxidant inside it. Benalu teh was extracted using traditional and batch reactor with different solvents (water, 30, 50, 70 and 99% ethanol at different temperatures (40-180°C for different time periods (10-20 min under additional pressure 0.2 MPa. Results: The best extraction condition by batch reactor extraction was 30% ethanol solvent at temperature 100°C for 10 min. Conclusion: Batch reactor extraction gave a better result than traditional extraction on extract yield, radical scavenging activities and total phenolic compound compared with the traditional extraction.

  15. Feasibility of treating partially soluble wastewater in anaerobic sequencing batch biofilm reactor (ASBBR) with mechanical stirring.

    Science.gov (United States)

    Pinho, Samantha Cristina; Ratusznei, Suzana Maria; Rodrigues, José Alberto Domingues; Foresti, Eugenio; Zaiat, Marcelo

    2005-03-01

    This work reports on the treatment of partially soluble wastewater in an anaerobic sequencing batch biofilm reactor, containing biomass immobilized on polyurethane matrices and stirred mechanically. The results showed that agitation provided optimal mixing and improved the overall organic matter consumption rates. The system showed to be feasible to enhance the treatment of partially soluble wastewaters. PMID:15491835

  16. Performance of Continuous Micro Photo Reactor – Comparison with Batch Process

    Czech Academy of Sciences Publication Activity Database

    Drhová, Magdalena; Hejda, S.; Křišťál, Jiří; Klusoň, Petr

    Praha: Orgit, 2012, P1.166. ISBN 978-80-905035-1-9. [International Congress of Chemical and Process Engineering CHISA 2012 and 15th Conference PRES 2012 /20./. Prague (CZ), 25.08.2012-29.08.2012] Institutional support: RVO:67985858 Keywords : batch process * micro photo reactor * photooxydation Subject RIV: CI - Industrial Chemistry, Chemical Engineering www.chisa.cz/2012

  17. Bagasse hydrolyzates from Agave tequilana as substrates for succinic acid production by Actinobacillus succinogenes in batch and repeated batch reactor.

    Science.gov (United States)

    Corona-González, Rosa Isela; Varela-Almanza, Karla María; Arriola-Guevara, Enrique; Martínez-Gómez, Álvaro de Jesús; Pelayo-Ortiz, Carlos; Toriz, Guillermo

    2016-04-01

    The aim of this work was to obtain fermentable sugars by enzymatic or acid hydrolyses of Agave tequilana Weber bagasse in order to produce succinic acid with Actinobacillus succinogenes. Hydrolyses were carried out with mineral acids (sulfuric and hydrochloric acids) or a commercial cellulolytic enzyme, and were optimized statistically by a response surface methodology, having as factors the concentration of acid/enzyme and time of hydrolysis. The concentration of sugars obtained at optimal conditions for each hydrolysis were 21.7, 22.4y 19.8g/L for H2SO4, HCl and the enzymatic preparation respectively. Concerning succinic acid production, the enzymatic hydrolyzates resulted in the highest yield (0.446g/g) and productivity (0.57g/Lh) using A. succinogenes in a batch reactor system. Repeated batch fermentation with immobilized A. succinogenes in agar and with the enzymatic hydrolyzates resulted in a maximum concentration of succinic acid of 33.6g/L from 87.2g/L monosaccharides after 5 cycles in 40h, obtaining a productivity of 1.32g/Lh. PMID:26802183

  18. Biodegradation of phenanthrene in an anaerobic batch reactor: growth kinetics

    Directory of Open Access Journals (Sweden)

    H.S. Nasrollahzadeh

    2010-07-01

    Full Text Available The purpose of the present research was to demonstrate the ability of mixed consortia of microorganisms to degrade high concentrations of phenanthrene (PHE as the sole carbon source. Batch experiments were carried out by the induction of mineral salt medium containing PHE to the seed culture and monitoring PHE biodegradation. The microbial propagation was conducted using PHE concentrations in the range of 20 to 100 mg/l. The microbial growth on PHE was defined based on Monod and modified Logistic rate models. The kinetic studies revealed that maximum specific growth rates (μm for PHE concentrations of 20, 50 and 100 mg/l were 0.12, 0.23 and 0.035 h-1, respectively. The doubling times for microbial population in PHE concentrations of 20, 50 and 100 mg/l were 13, 15 and 17.5 h, respectively. Also, maximum cell dry weight (xm of 54.23 mg/l was achieved, while the inhibition coefficient was 0.023 h-1. It was observed that the experimental data were well represented by the proposed models. It was also found that the biodegradation of PHE was successfully performed by the isolated strains.

  19. Simultaneous nitrification-denitrification and phosphorus removal in a fixed bed sequencing batch reactor (FBSBR)

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, Yousef, E-mail: you.rahimi@gmail.com [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave, Tehran (Iran, Islamic Republic of); Torabian, Ali, E-mail: atorabi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave, Tehran (Iran, Islamic Republic of); Mehrdadi, Naser, E-mail: mehrdadi@ut.ac.ir [Department of Civil and Environmental Engineering, Graduate Faculty of Environment, University of Tehran, No. 25 Qods St., Enghelab Ave, Tehran (Iran, Islamic Republic of); Shahmoradi, Behzad, E-mail: bshahmorady@gmail.com [Department of Environmental Science, University of Mysore, MGM-06 Mysore (India)

    2011-01-30

    Research highlights: {yields} Sludge production in FSBR reactor is 20-30% less than SBR reactor. {yields} FSBR reactor showed more nutrient removal rate than SBR reactor. {yields} FSBR reactor showed less VSS/TSS ratio than SBR reactor. - Abstract: Biological nutrient removal (BNR) was investigated in a fixed bed sequencing batch reactor (FBSBR) in which instead of activated sludge polypropylene carriers were used. The FBSBR performance on carbon and nitrogen removal at different loading rates was significant. COD, TN, and phosphorus removal efficiencies were at range of 90-96%, 60-88%, and 76-90% respectively while these values at SBR reactor were 85-95%, 38-60%, and 20-79% respectively. These results show that the simultaneous nitrification-denitrification (SND) is significantly higher than conventional SBR reactor. The higher total phosphorus (TP) removal in FBSBR correlates with oxygen gradient in biofilm layer. The influence of fixed media on biomass production yield was assessed by monitoring the MLSS concentrations versus COD removal for both reactors and results revealed that the sludge production yield (Y{sub obs}) is significantly less in FBSBR reactors compared with SBR reactor. The FBSBR was more efficient in SND and phosphorus removal. Moreover, it produced less excess sludge but higher in nutrient content and stabilization ratio (less VSS/TSS ratio).

  20. Simultaneous nitrification-denitrification and phosphorus removal in a fixed bed sequencing batch reactor (FBSBR)

    International Nuclear Information System (INIS)

    Research highlights: → Sludge production in FSBR reactor is 20-30% less than SBR reactor. → FSBR reactor showed more nutrient removal rate than SBR reactor. → FSBR reactor showed less VSS/TSS ratio than SBR reactor. - Abstract: Biological nutrient removal (BNR) was investigated in a fixed bed sequencing batch reactor (FBSBR) in which instead of activated sludge polypropylene carriers were used. The FBSBR performance on carbon and nitrogen removal at different loading rates was significant. COD, TN, and phosphorus removal efficiencies were at range of 90-96%, 60-88%, and 76-90% respectively while these values at SBR reactor were 85-95%, 38-60%, and 20-79% respectively. These results show that the simultaneous nitrification-denitrification (SND) is significantly higher than conventional SBR reactor. The higher total phosphorus (TP) removal in FBSBR correlates with oxygen gradient in biofilm layer. The influence of fixed media on biomass production yield was assessed by monitoring the MLSS concentrations versus COD removal for both reactors and results revealed that the sludge production yield (Yobs) is significantly less in FBSBR reactors compared with SBR reactor. The FBSBR was more efficient in SND and phosphorus removal. Moreover, it produced less excess sludge but higher in nutrient content and stabilization ratio (less VSS/TSS ratio).

  1. Role of Moving Bed Biofilm Reactor and Sequencing Batch Reactor in Biological Degradation of Formaldehyde Wastewater

    Directory of Open Access Journals (Sweden)

    B. Ayati

    2011-10-01

    Full Text Available Nowadays formaldehyde is used as raw material in many industries. It has also disinfection applications in some public places. Due to its toxicity for microorganisms, chemical or anaerobic biological methods are applied for treating wastewater containing formaldehyde.In this research, formaldehyde removal efficiencies of aerobic biological treatment systems including moving bed biofilm (MMBR and sequencing batch reactors (SBR were investigated. During all experiments, the efficiency of SBR was more than MBBR, but the difference was not significant statistically. According to the results, the best efficiencies were obtained for influent formaldehyde COD of 200 mg/L in MBBR and SBR which were 93% and 99.4%, respectively. The systems were also capable to treat higher formaldehyde concentrations (up to 2500 mg/L with lower removal efficiency. The reaction kinetics followed the Stover-Kincannon second order model. The gram-positive and gram-negative bacillus and coccus as well as the gram-positive binary bacillus were found to be the most dominant species. The results of 13C-NMR analysis have shown that formaldehyde and urea were converted into N-{[(aminocarbonyl amino] methyl}urea and the residual formaldehyde was polymerized at room temperature.

  2. Comparison of heavy metal toxicity in continuous flow and batch reactors

    Science.gov (United States)

    Sengor, S. S.; Gikas, P.; Moberly, J. G.; Peyton, B. M.; Ginn, T. R.

    2009-12-01

    The presence of heavy metals may significantly affect microbial growth. In many cases, small amounts of particular heavy metals may stimulate microbial growth; however, larger quantities may result in microbial growth reduction. Environmental parameters, such as growth pattern may alter the critical heavy metal concentration, above which microbial growth stimulation turns to growth inhibition. Thus, it is important to quantify the effects of heavy metals on microbial activity for understanding natural or manmade biological reactors, either in situ or ex situ. Here we compare the toxicity of Zn and Cu on Arthrobacter sp., a heavy metal tolerant microorganism, under continuous flow versus batch reactor operations. Batch and continuous growth tests of Arthrobacter sp. were carried out at various individual and combined concentrations of Zn and Cu. Biomass concentration (OD) was measured for both the batch and continuous reactors, whereas ATP, oxygen uptake rates and substrate concentrations were additionally measured for the continuous system. Results indicated that Cu was more toxic than Zn under all conditions for both systems. In batch reactors, all tested Zn concentrations up to 150 uM showed a stimulatory effect on microbial growth. However, in the case of mixed Zn and Cu exposures, the presence of Zn either eliminated (at the 50 uM level both Zn and Cu) or reduced by ~25% (at the 100 and 150 uM levels both Zn and Cu) the Cu-induced inhibition. In the continuous system, only one test involved combined Cu (40uM) and Zn (125uM) and this test showed similar results to the 40uM Cu continuous test, i.e., no reduction in inhibition. The specific ATP concentration, i.e., ATP/OD, results for the continuous reactor showed an apparent recovery for both Cu-treated populations, although neither the OD nor glucose data showed any recovery. This may reflect that the individual microorganisms that survived after the addition of heavy metals, kept maintaining the usual ATP

  3. Development of a mathematical model for the dynamic optimization of batch reactors, and MINLP synthesis of plug-flow reactors in complex networks

    OpenAIRE

    Ropotar, Marcel; Kravanja, Zdravko

    2012-01-01

    This paper describes the development of a robust and efficient reactor model suitable for representing batch and plugflow reactors (PFRs) in different applications. These would range from the nonlinear (NLP) dynamic optimization of a stand-alone batch reactor up to the mixed-integer nonlinear (MINLP) synthesis of a complex reactor network in overall process schemes. Different schemes for the Orthogonal Collocation on Finite Element (OCFE) and various model formulations, in the case of MINLP m...

  4. INVESTIGATION OF INTERMITTENT CHLORINATION SYSTEM IN BIOLOGICAL EXCESS SLUDGE REDUCTION BY SEQUENCING BATCH REACTORS

    Directory of Open Access Journals (Sweden)

    A. Takdastan ، N. Mehrdadi ، A. A. Azimi ، A. Torabian ، G. Nabi Bidhendi

    2009-01-01

    Full Text Available The excessive biological sludge production is one of the disadvantages of aerobic wastewater treatment processes such as sequencing batch reactors. To solve the problem of excess sludge production, oxidizing some of the sludge by chlorine, thus reducing the biomass coefficient as well as the sewage sludge disposal may be a suitable idea. In this study, two sequencing batch reactors, each with 20 L volume and controlled by on-line system were used. After providing the steady state conditions in the reactors, sampling and testing of parameters were done during 8 months. The results showed that during the solid retention time of 10 days the kinetic coefficient of Y and Kd were 0.58 mg biomass/mg COD and 0.058/day, respectively. At the next stage, different concentrations of chlorine were used in the reactors intermittently. Results showed that 15 mg chlorine/gMLSS in the reactor was able to reduce the yield coefficient from 0.58 to 0.3 mg biomass/mg COD. In other words, the biological excess sludge was reduced about 48%. But the soluble chemical oxygen demand increased slightly in the effluent and the removal percentage decreased from 95% in the blank reactor to 55% in the test reactor.

  5. Low-biodegradable composite chemical wastewater treatment by biofilm configured sequencing batch reactor (SBBR)

    International Nuclear Information System (INIS)

    Biofilm configured system with sequencing/periodic discontinuous batch mode operation was evaluated for the treatment of low-biodegradable composite chemical wastewater (low BOD/COD ratio ∼0.3, high sulfate content: 1.75 g/l) in aerobic metabolic function. Reactor was operated under anoxic-aerobic-anoxic microenvironment conditions with a total cycle period of 24 h [fill: 15 min; reaction: 23 h (aeration along with recirculation); settle: 30 min; decant: 15 min] and the performance of the system was studied at organic loading rates (OLR) of 0.92, 1.50, 3.07 and 4.76 kg COD/cum-day. Substrate utilization showed a steady increase with increase in OLR and system performance sustained at higher loading rates. Maximum non-cumulative substrate utilization was observed after 4 h of the cycle operation. Sulfate removal efficiency of 20% was observed due to the induced anoxic conditions prevailing during the sequence phase operation of the reactor and the existing internal anoxic zones in the biofilm matrix. Biofilm configured sequencing batch reactor (SBR) showed comparatively higher efficiency to the corresponding suspended growth and granular activated carbon (GAC) configured systems studied with same wastewater. Periodic discontinuous batch mode operation of the biofilm reactors results in a more even distribution of the biomass throughout the reactor and was able to treat large shock loads than the continuous flow process. Biofilm configured system coupled with periodic discontinuous batch mode operation imposes regular variations in the substrate concentration on biofilm organisms. As a result, organisms throughout the film achieve maximum growth rates resulting in improved reaction potential leading to stable and robust system which is well suited for treating highly variable wastes

  6. A Novel Approach to Materials Development for Advanced Reactor Systems. Quarterly Progress Report, Year 1; Quarter 4

    Energy Technology Data Exchange (ETDEWEB)

    Was, G.S.; Atzmon, M.; Wang, L.

    2000-09-28

    OAK B188 A Novel Approach to Materials Development for Advanced Reactor Systems. Quarterly Progress Report, Year 1; Quarter 4. Year one of this project had three major goals. First, to specify, order and install a new high current ion source for more rapid and stable proton irradiation. Second, to assess the use of chromium pre-enrichment and hardening by combining cold-work and irradiation in an effort to isolate a radiation damage microstructure in stainless steel without the effects of RIS. Third, to initiate irradiation of reactor pressure vessel steel and Zircaloy. In year 1 quarter 4, the project goal was to begin characterization of the microstructure of model alloys of RPV steels irradiated over a range of doses. We also planned to prepare samples for microstructure isolation in stainless steels, and to receive and characterize Zircaloy samples for subsequent irradiation.

  7. Elimination of water pathogens with solar radiation using an automated sequential batch CPC reactor

    Energy Technology Data Exchange (ETDEWEB)

    Polo-Lopez, M.I., E-mail: mpolo@psa.es [Plataforma Solar de Almeria - CIEMAT, PO Box 22, 04200 Tabernas, Almeria (Spain); Fernandez-Ibanez, P., E-mail: pilar.fernandez@psa.es [Plataforma Solar de Almeria - CIEMAT, PO Box 22, 04200 Tabernas, Almeria (Spain); Ubomba-Jaswa, E., E-mail: euniceubombajaswa@yahoo.com [Natural Resources and the Environment, CSIR, PO Box 395, Pretoria (South Africa); Navntoft, C., E-mail: christian.navntoft@solarmate.com.ar [Instituto de Investigacion e Ingenieria Ambiental, Universidad Nacional de San Martin (3iA-UNSAM), Peatonal Belgrano 3563, B1650ANQ San Martin (Argentina); Universidad Tecnologica Nacional - Facultad Regional Buenos Aires - Departamento de Ingenieria Civil - Laboratorio de Estudios sobre Energia Solar, (UTN-FRBA-LESES), Mozart 2300, (1407) Ciudad Autonoma de Buenos Aires, Republica Argentina (Argentina); Garcia-Fernandez, I., E-mail: irene.garcia@psa.es [Plataforma Solar de Almeria - CIEMAT, PO Box 22, 04200 Tabernas, Almeria (Spain); Dunlop, P.S.M., E-mail: psm.dunlop@ulster.ac.uk [Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2 (Ireland); Schmid, M. [Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2 (Ireland); Byrne, J.A., E-mail: j.byrne@ulster.ac.uk [Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin 2 (Ireland); and others

    2011-11-30

    Solar disinfection (SODIS) of water is a well-known, effective treatment process which is practiced at household level in many developing countries. However, this process is limited by the small volume treated and there is no indication of treatment efficacy for the user. Low cost glass tube reactors, together with compound parabolic collector (CPC) technology, have been shown to significantly increase the efficiency of solar disinfection. However, these reactors still require user input to control each batch SODIS process and there is no feedback that the process is complete. Automatic operation of the batch SODIS process, controlled by UVA-radiation sensors, can provide information on the status of the process, can ensure the required UVA dose to achieve complete disinfection is received and reduces user work-load through automatic sequential batch processing. In this work, an enhanced CPC photo-reactor with a concentration factor of 1.89 was developed. The apparatus was automated to achieve exposure to a pre-determined UVA dose. Treated water was automatically dispensed into a reservoir tank. The reactor was tested using Escherichia coli as a model pathogen in natural well water. A 6-log inactivation of E. coli was achieved following exposure to the minimum uninterrupted lethal UVA dose. The enhanced reactor decreased the exposure time required to achieve the lethal UVA dose, in comparison to a CPC system with a concentration factor of 1.0. Doubling the lethal UVA dose prevented the need for a period of post-exposure dark inactivation and reduced the overall treatment time. Using this reactor, SODIS can be automatically carried out at an affordable cost, with reduced exposure time and minimal user input.

  8. Elimination of water pathogens with solar radiation using an automated sequential batch CPC reactor

    International Nuclear Information System (INIS)

    Solar disinfection (SODIS) of water is a well-known, effective treatment process which is practiced at household level in many developing countries. However, this process is limited by the small volume treated and there is no indication of treatment efficacy for the user. Low cost glass tube reactors, together with compound parabolic collector (CPC) technology, have been shown to significantly increase the efficiency of solar disinfection. However, these reactors still require user input to control each batch SODIS process and there is no feedback that the process is complete. Automatic operation of the batch SODIS process, controlled by UVA-radiation sensors, can provide information on the status of the process, can ensure the required UVA dose to achieve complete disinfection is received and reduces user work-load through automatic sequential batch processing. In this work, an enhanced CPC photo-reactor with a concentration factor of 1.89 was developed. The apparatus was automated to achieve exposure to a pre-determined UVA dose. Treated water was automatically dispensed into a reservoir tank. The reactor was tested using Escherichia coli as a model pathogen in natural well water. A 6-log inactivation of E. coli was achieved following exposure to the minimum uninterrupted lethal UVA dose. The enhanced reactor decreased the exposure time required to achieve the lethal UVA dose, in comparison to a CPC system with a concentration factor of 1.0. Doubling the lethal UVA dose prevented the need for a period of post-exposure dark inactivation and reduced the overall treatment time. Using this reactor, SODIS can be automatically carried out at an affordable cost, with reduced exposure time and minimal user input.

  9. Hydrodesulfurization of light gas oil: Kinetic determination in a batch reactor

    OpenAIRE

    Skala Dejan U.; Orlović Aleksandar M.; Marković Branislav; Tarlecki-Barićević Ana; Jovanović Dušan M.

    2002-01-01

    The performed investigations were directed toward the analysis of the performance and activity of the fresh and regenerated Cyanamid HDS 20C catalyst in a laboratory batch reactor (2 dm3) for the HDS of the diesel fraction (light gas oil, LGO). Testing of the regenerated catalyst was performed with light gas oil (LGO) of different characteristics. The determined values of the reaction rate constant were compared to some published data in the literature for the HDS of specific sulfur compounds...

  10. EFFECTS OF HOT WATER EXTRACTION IN A BATCH REACTOR ON THE DELIGNIFICATION OF BIRCH WOOD

    OpenAIRE

    Marc Borrega; Kaarlo Nieminen; Herbert Sixta

    2011-01-01

    The amount of residual lignin in birch wood after a hot water extraction in a batch reactor was investigated as a function of extraction temperature and time. A kinetic model fitting the experimental data was then developed to explain delignification of wood during a hot water treatment. Results showed that delignification kinetics involves simultaneous degradation and condensation reactions, with degradation of lignin being much faster than its condensation. Native lignin in wood was success...

  11. 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...

  12. Comparison of Reductive Dechlorination of Chlorinated Ethylene in Batch and Continuous-Flow Reactor

    Science.gov (United States)

    Park, S.; Jonghwan, L.; Hong, U.; Kim, N.; Ahn, H.; Lee, S.; Kim, Y.

    2010-12-01

    A 1.28 L-Batch reactor and continuous-flow stirred tank reactor (CFSTR) fed with formate and trichloriethene (TCE) were operated for 120 days and 72 days, respectively, to study the effect of formate as electron donor on reductive dechlorination of TCE to cis-1,2-dichloroethylene (c-DCE), vinyl chloride (VC), and ethylene (ETH). In batch reactor, injected 60 μmol TCE was completely degraded in presence of 20% hydrogen gas (H2) in less than 8 days by Evanite culture (300 mg-soluble protein) with ability to completely degrade tetrachloroethene (PCE) and TCE to ETH under anaerobic conditions. To determine the effect of formate as electron donor instead of H2, about 3 or 11 mmol of formate injected into batch-reactor every 15 days was enough to support H2 for dechlorination of c-DCE to VC and ETH. Soluble protein concentration of Evanite culture during the batch test increased from 300 mg to 688 mg for 120 days. In CFSTR test, TCE was fed continuously at 9.9 ppm (75.38 μmol/L) and the influent formate feed concentration increased stepwise from 1.3 mmol/L to 14.3 mmol/L. Injected TCE was accumulated at HRT 18 days for 13 days, but TCE was completed degraded at HRT 36 days without accumulation during left of experiment period, getting H2 from fermentative hydrogen production of injected formate. Although c-DCE was also accumulated for 23 days after CFSTR operation, it reached steady-state without accumulation in presence of excessive formate. However, since c-DCE in CFSTR was not completely dechlorinated, we will determine the transcriptional level of enzyme involved in reductive dechlorination of TCE, c-DCE, and VC in our future work.

  13. Treatment of Slaughter House Wastewater in a Sequencing Batch Reactor: Performance Evaluation and Biodegradation Kinetics

    OpenAIRE

    Pradyut Kundu; Anupam Debsarkar; Somnath Mukherjee

    2013-01-01

    Slaughterhouse wastewater contains diluted blood, protein, fat, and suspended solids, as a result the organic and nutrient concentration in this wastewater is vary high and the residues are partially solubilized, leading to a highly contaminating effect in riverbeds and other water bodies if the same is let off untreated. The performance of a laboratory-scale Sequencing Batch Reactor (SBR) has been investigated in aerobic-anoxic sequential mode for simultaneous removal of organic carbon and n...

  14. Study of nitrifying sequencing batch reactor in presence of m-Cresol

    International Nuclear Information System (INIS)

    The process of the nitrification has been studied scantly in presence of phenolic compounds such as m-cresol. the aim of this study was evaluate the tolerance of a nitrifying SBR (Sequencing Batch Reactor) to m-cresol and the ability of the sludge to consume this phenolic compound. Nitrification is the process of oxidation of ammonia to nitrite and nitrate by lithoautotrophic ammonia-and nitrite-oxidizing bacteria. (Author)

  15. The Effects of Batch Reactor Extraction on Antioxidant Activity from Scurulla atropurpurea

    OpenAIRE

    Siti I. Rahmawati; Nobuyuki Hayashi

    2012-01-01

    Problem statement: The main active compounds of benalu tehs include alkaloids and flavonoids, therefore antioxidant of it has big potential to develop. In the context of extraction, the traditional (boiling in the water until one-third remain) extraction require a long extraction time and result in low yields of extraction also antioxidant activities. Approach: Batch reactor is extraction at high temperature under applied pressure to keep the solvent under liquid phase, by this technology we ...

  16. Characteristics of aerobic granules grown on glucose a sequential batch shaking reactor

    Institute of Scientific and Technical Information of China (English)

    CAI Chun-guang; ZHU Nan-wen; LIU Jun-shen; WANG Zhen-peng; CAI Wei-min

    2004-01-01

    Aerobic heterotrophic granular sludge was cultivated in a sequencing batch shaking reactor(SBSR) in which a synthetic wastewater containing glucose as carbon source was fed. The characteristics of the aerobic granules were investigated. Compared with the conventional activated sludge flocs, the aerobic granules exhibit excellent physical characteristics in terms of settleability, size, shape, biomass density, and physical strength.Scanning electron micrographs revealed that in mature granules little filamentous bacteria could be found, rodshaped and coccoid bacteria were the dominant microorganisms.

  17. Kinetic Study of COS with Tertiary Alkanolamine Solutions. 1. Experiments in an Intensely Stirred Batch Reactor

    OpenAIRE

    Littel, Rob J.; Versteeg, Geert F.; Swaaij, Wim P.M. van

    1992-01-01

    The reaction between COS and various tertiary alkanolamines in aqueous solutions has been studied in an intensely stirred batch reactor. Experiments for TEA, DMMEA, and DEMEA were carried out at 303 K; the reaction between COS and aqueous MDEA has been studied at temperatures ranging from 293 to 323 K. A two-step reaction mechanism has been proposed which describes all observed phenomena. This mechanism can be regarded as the base-catalyzed analogue of the reaction mechanism for the hydrolysi...

  18. Asymptotic Modelling of Crystallisation in Two Layers Systems. Application to Methane Hydrate Formation in Batch Reactor.

    OpenAIRE

    Cournil, Michel; Herri, Jean-Michel

    2002-01-01

    This paper proposes to re-visit the problem of gas-liquid crystallization in the framework of a two-layer model and with the help of data coming from experiments on methane hydrate crystallization in a semi-batch reactor. Preliminary quantitative discussion of the order of magnitude of different effects makes possible realistic simplifications in the theoretical models. In particular, the role of the interfacial film is clearly defined. As previous authors did, we use a formulation in terms o...

  19. Optimality of affine control system of several species in competition on a Sequential Batch Reactor

    OpenAIRE

    Rodriguez, J. C.; Ramirez, Hector; Gajardo, Pedro; Rapaport, Alain

    2014-01-01

    In this paper we analyze the optimalty of affine control system of several species in competition for a single substrate on a Sequential Batch Reactors (SBR), with the objective being to reach a given (low) level of the substrate. We allow controls to be bounded measurable functions of time plus possible impulses. A suitable modification of the dynamics leads to a slightly different optimal control problem, without impulsive controls, for which we apply different optimality conditions de-rive...

  20. Effect of internal recirculation velocity in an anaerobic sequencing batch reactor (ASBR

    Directory of Open Access Journals (Sweden)

    G. Z. Maurina

    2014-12-01

    Full Text Available This paper discusses the effect of different internal recirculation velocities on the mixture and shear stress on the flocs in an anaerobic sequencing batch reactor (ASBR. Thus, simulations are performed using a computational fluid dynamics (CFD tool to evaluate this dependency. The analysis of velocities and turbulent kinetic energy indicates that the highest flow evaluated (0.003 m³/s results in better mixing within the reactor. However, care must be taken with the recycling pipe size, in order to maintain the shear stress inside the range of optimal values.

  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. Nitrifying and denitrifying bacteria in aerobic granules formed in sequencing batch airlift reactors

    Institute of Scientific and Technical Information of China (English)

    WANG Fang; YANG Fenglin; QI Aijiu

    2007-01-01

    The purpose of this study was to investigate nitrifying bacteria and denitrifying bacteria isolated from aerobic granules.Aerobic granules were formed in an internal-circulate sequencing batch airlift reactor(SBAR)and biodegradation of NH3 -N was analyzed in the reactor.Bacteria were isolated and determined from aerobic granules using selected media.The growth properties and morphology of bacteria colonies were observed by controlling aerobic or anaerobic conditions in the culture medium.It was found that bacteria in aerobic granules were diverse and some of them were facultative aerobes.The diversity of bacteria in aerobic granules was a premise of simultaneous nitrification and denitrification.

  3. Performance of anaerobic sequencing batch reactors (pilot-scale) in domestic sewage treatment

    OpenAIRE

    Eugenio Foresti; Marcelo Zaiat; Arnaldo Sarti

    2005-01-01

    This study shows the results obtained during 70 days using four pilot scale anaerobic sequencing batch reactors, for sewage system treatment of the campus of the University of São Paulo in São Carlos – SP. Each reactor system with 1.2 m³ of total volume, was designed for the treatment of 1.95 m³d³ of domestic sewage, with geometrical conceptions (ratio H-height/D-diameter), mechanical conceptions (mechanical mixing or liquid re-circulation) and different biomass retention type. Three of them ...

  4. A BATCH REACTOR CONSTRUCTION FOR OBTAINING BIODIESEL FROM OIL Ricinus communis

    OpenAIRE

    Yolimar Fernández; Osmely Floiran; Era Maurelys; Milena Villalobos; América Garcia

    2014-01-01

    A batch reactor was constructed to obtain biodiesel from 5 liters of extracted from the seed of Ricinus communis. The reactor is made of stainless steel, 29cm length, 15.24 cm of inner diameter and a conical base of 20cm long, wall thickness of 0.2 cm, 1000 W tubular resistance and 110 volt motor. It is extracted and compared with the respective norms the physical and chemical properties of crude oil. Preliminary tests catalyzed transesterification of the oil with NaOH to verify the feasibil...

  5. Aerobic Sludge Granulation in a Full-Scale Sequencing Batch Reactor

    OpenAIRE

    2014-01-01

    Aerobic granulation of activated sludge was successfully achieved in a full-scale sequencing batch reactor (SBR) with 50,000 m3 d−1 for treating a town's wastewater. After operation for 337 days, in this full-scale SBR, aerobic granules with an average SVI30 of 47.1 mL g−1, diameter of 0.5 mm, and settling velocity of 42 m h−1 were obtained. Compared to an anaerobic/oxic plug flow (A/O) reactor and an oxidation ditch (OD) being operated in this wastewater treatment plant, the sludge from full...

  6. EFFECTS OF 4-CHLOROPHENOL LOADINGS ON ACCLIMATION OF BIOMASS WITH OPTIMIZED FIXED TIME SEQUENCING BATCH REACTOR

    Directory of Open Access Journals (Sweden)

    H. Movahedyan, A. Assadi, M. M. Amin

    2008-10-01

    Full Text Available Abstract: Chlorinated phenols in many industrial effluents are usually difficult to be removed by conventional biological treatment processes. Performance of the aerobic sequencing batch reactor treating 4-chlorophenol containing wastewater at different loadings rates from 0.0075 to 1.2 g4CP/L.d was evaluated. The sequencing batch reactor was operated with fill, react, settle and decant phases in the order of 10:370:90:10 min, respectively, for a cycle time of 8 h at 10 days solid retention time and 16 h hydraulic retention time in the stable period. The effects of 4-chlorophenol loadings on the 4-chlorophenol and chemical oxygen demand removal percents, yield coefficient (Y, biomass variation and sludge volume index were investigated. High chemical oxygen demand removal efficiencies (95±3.5% and approximately complete 4-chlorophenol removal (>99% were observed even in the absence of growth substrate. The degradation of 4-chlorophenol led to formation of 5-chloro-2-hydroxymuconic semialdehyde, which was more oxidized, indicating complete disappearance of 4-chlorophenol via meta-cleavage pathway. A compact sludge with excellent settleability (sludge volume index=47±6.1 mL/g developed during entire acclimation period. High removal efficiencies with sequencing batch reactor may be due to enforced short term unsteady state conditions coupled with periodic exposure of the microorganisms to defined process conditions which facilitate the required metabolic pathways for treating xenobiotics containing wastewater.

  7. Influence of different substrates on the formation and characteristics of aerobic granules in sequencing batch reactors

    Institute of Scientific and Technical Information of China (English)

    SUN Fei-yun; YANG Cheng-yong; LI Jiu-yi; YANG Ya-jing

    2006-01-01

    The effects of different substrates on the aerobic granulation process were studied using laboratory-scale sequencing batch reactors (SBRs). Four parallel granules sequencing batch reactors (GSBR): R1, R2, R3, and R4 were fed with acetate, glucose, peptone and fecula, respectively. Stable aerobic granules were successfully cultivated in R1, R2, R4, and smaller granules less than 500 μm were formed in R3. Morphology and the physic-chemical characteristics of aerobic granules fed with different carbon substrates were investigated by the four reactors operated under the same pressure. The aerobic granules in the four reactors were observed and found that peptone was the most stable one due to its good settleability even after a sludge age as short as l0 d. A strong correlation was testified between the characteristics of aerobic granules and the properties of carbon substrates. The stability of aerobic granules was affected by extracellular polymer substances (EPS) derived from microorganism growth during feast time fed with different carbon substrates, and the influence of the property of storage substance was greater than that of its quantity. Optimal carbon substrates, which are helpful in the cultivation and retention of well-settling granules and in the enhancement of the overall ability of the aerobic granules reactors, were found.

  8. Effect of different salt adaptation strategies on the microbial diversity, activity, and settling of nitrifying sludge in sequencing batch reactors

    NARCIS (Netherlands)

    Bassin, J.P.; Kleerebezem, R.; Muyzer, G.; Rosado, A.S.; Van Loosdrecht, M.C.M.; Dezotti, M.

    2011-01-01

    The effect of salinity on the activity of nitrifying bacteria, floc characteristics, and microbial community structure accessed by fluorescent in situ hybridization and polymerase chain reaction–denaturing gradient gel electrophoresis techniques was investigated. Two sequencing batch reactors (SRB1

  9. A KINETIC MODEL FOR H2O2/UV PROCESS IN A COMPLETELY MIXED BATCH REACTOR. (R825370C076)

    Science.gov (United States)

    A dynamic kinetic model for the advanced oxidation process (AOP) using hydrogen peroxide and ultraviolet irradiation (H2O2/UV) in a completely mixed batch reactor (CMBR) is developed. The model includes the known elementary chemical and photochemical reac...

  10. Effect of auxotrophies on yeast performance in aerated fed-batch reactor

    Energy Technology Data Exchange (ETDEWEB)

    Landi, Carmine; Paciello, Lucia [Dept. Ingegneria Industriale, Universita di Salerno, Via Ponte Don Melillo, 84084 Fisciano, Salerno (Italy); Alteriis, Elisabetta de [Dept. Biologia Strutturale e Funzionale, Universita degli Studi di Napoli ' Federico II' , Via Cinthia, 80100 Napoli (Italy); Brambilla, Luca [Dept. Biotecnologie e Bioscienze, Universita Milano-Bicocca, Piazza della Scienza, 20126 Milano (Italy); Parascandola, Palma, E-mail: pparascandola@unisa.it [Dept. Ingegneria Industriale, Universita di Salerno, Via Ponte Don Melillo, 84084 Fisciano, Salerno (Italy)

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer The paper contributes to fill the gap existing between the basic and applied research. Black-Right-Pointing-Pointer Mathematical model sheds light on the physiology of auxotrophic yeast strains. Black-Right-Pointing-Pointer Yeast behavior in fed-batch is influenced by biological and environmental determinants. Black-Right-Pointing-Pointer Process optimization would make possible the production of heterologous proteins which are not yet on the market. -- Abstract: A systematic investigation on the effects of auxotrophies on the performance of yeast in aerated fed-batch reactor was carried out. Six isogenic strains from the CEN.PK family of Saccharomyces cerevisiae, one prototroph and five auxotrophs, were grown in aerated fed-batch reactor using the same operative conditions and a proper nutritional supplementation. The performance of the strains, in terms of final biomass decreased with increasing the number of auxotrophies. Auxotrophy for leucine exerted a profound negative effect on the performance of the strains. Accumulation of reactive oxygen species (ROS) in the cells of the strain carrying four auxotrophies and its significant viability loss, were indicative of an oxidative stress response induced by exposure of cells to the environmental conditions. The mathematical model was fundamental to highlight how the carbon flux, depending on the number and type of auxotrophies, was diverted towards the production of increasingly large quantities of energy for maintenance.

  11. Effect of auxotrophies on yeast performance in aerated fed-batch reactor

    International Nuclear Information System (INIS)

    Highlights: ► The paper contributes to fill the gap existing between the basic and applied research. ► Mathematical model sheds light on the physiology of auxotrophic yeast strains. ► Yeast behavior in fed-batch is influenced by biological and environmental determinants. ► Process optimization would make possible the production of heterologous proteins which are not yet on the market. -- Abstract: A systematic investigation on the effects of auxotrophies on the performance of yeast in aerated fed-batch reactor was carried out. Six isogenic strains from the CEN.PK family of Saccharomyces cerevisiae, one prototroph and five auxotrophs, were grown in aerated fed-batch reactor using the same operative conditions and a proper nutritional supplementation. The performance of the strains, in terms of final biomass decreased with increasing the number of auxotrophies. Auxotrophy for leucine exerted a profound negative effect on the performance of the strains. Accumulation of reactive oxygen species (ROS) in the cells of the strain carrying four auxotrophies and its significant viability loss, were indicative of an oxidative stress response induced by exposure of cells to the environmental conditions. The mathematical model was fundamental to highlight how the carbon flux, depending on the number and type of auxotrophies, was diverted towards the production of increasingly large quantities of energy for maintenance.

  12. Evolutionary Strategy for Feeding Trajectory Optimization of Fed-batch Reactors

    Directory of Open Access Journals (Sweden)

    Tamás Varga

    2007-12-01

    Full Text Available Safe and optimal operation of complex production processes is one of the mostimportant research and development problems in process engineering. This problem is themost relevant at the design of the optimal feeding profile of fed-batch chemical reactorsdue to the nonlinear and unstable dynamical behavior of the processes. This paper showsthat how the optimal feeding policy can be determined in fed-batch reactors by sequentialquadratic programming, classical evolutionary strategy (ES and the advanced version ofES that is based on covariance matrix adaptation. A multi-objective function was createdand the search space was constrained in case of all of the three applied algorithms. Theswitching times between states in the feeding trajectory and the feed rates in each statewere manipulated to find the global minima of the objective function. To obtain the optimalfeeding policy the first-principle model of a pilot fed-batch reactor was implemented inMATLAB and applied as a dynamic simulator of the process. Off-line optimization processwas carried out in case of different dosing time distribution. As the results show asignificant improvement can be achieved in process performance applying advanced ESbased optimization algorithms to generate feeding trajectories.

  13. Ethanol production potential from fermented rice noodle wastewater treatment using entrapped yeast cell sequencing batch reactor

    Science.gov (United States)

    Siripattanakul-Ratpukdi, Sumana

    2012-03-01

    Fermented rice noodle production generates a large volume of starch-based wastewater. This study investigated the treatment of the fermented rice noodle wastewater using entrapped cell sequencing batch reactor (ECSBR) compared to traditional sequencing batch reactor (SBR). The yeast cells were applied because of their potential to convert reducing sugar in the wastewater to ethanol. In present study, preliminary treatment by acid hydrolysis was performed. A yeast culture, Saccharomyces cerevisiae, with calcium alginate cell entrapment was used. Optimum yeast cell loading in batch experiment and fermented rice noodle treatment performances using ECSBR and SBR systems were examined. In the first part, it was found that the cell loadings (0.6-2.7 × 108 cells/mL) did not play an important role in this study. Treatment reactions followed the second-order kinetics with the treatment efficiencies of 92-95%. In the second part, the result showed that ECSBR performed better than SBR in both treatment efficiency and system stability perspectives. ECSBR maintained glucose removal of 82.5 ± 10% for 5-cycle treatment while glucose removal by SBR declined from 96 to 40% within the 5-cycle treatment. Scanning electron microscopic images supported the treatment results. A number of yeast cells entrapped and attached onto the matrix grew in the entrapment matrix.

  14. Feasibility study for a passive trip system to prevent a runaway reaction in a batch reactor

    International Nuclear Information System (INIS)

    Reactors for carrying out exothermic reactions are amongst others equipped with trip systems. Normally these are active systems requiring a number of components such as sensors, pumps or valves to function for a successful trip. They may, for example, use the injection of a reaction inhibitor or the dumping of the reactor contents into a knock-out tank. The availability of such systems, i.e. their probability of functioning on demand, largely depends on their degree of redundancy. However, the possibility of common cause failures places a limit on increasing their availability by raising their degree of redundancy. Nevertheless, a trip system may reach a high availability if instead of stepping up its redundancy a passive system is used. The design of such a passive trip system for batch reactors is described and its feasibility is demonstrated by experimental investigations of three different types of reactions.

  15. Cultivation of aerobic granules in a novel configuration of sequencing batch airlift reactor.

    Science.gov (United States)

    Rezaei, Laya Siroos; Ayati, Bita; Ganjidoust, Hossein

    2012-01-01

    Aerobic granules can be formed in sequencing batch airlift reactors (SBAR) and sequencing batch reactors (SBR). Comparing these two systems, the SBAR has excellent mixing condition, but due to a high height-to-diameter ratio (H/D), there is no performance capability at full scale at the present time. This research examined a novel configuration of SBAR at laboratory scale (with a box structure) for industrial wastewater treatment. To evaluate chemical oxygen demand (COD) removal efficiency and granule formation of the novel reactor (R1), in comparison a conventional SBAR (R2) was operated under similar conditions during the experimental period. R1 and R2 with working volumes of 3.6 L and 4.5 L, respectively, were used to cultivate aerobic granules. Both reactors were operated for 4 h per cycle. Experiments were done at different organic loading rates (OLRs) ranging from 0.6-4.5 kg COD/m3.d for R1 and from 0.72-5.4 kg COD/m3.d for R2. After 150 days of operation, large-sized black filamentous granules with diameters of 0.5-2 mm and 2-11 mm were formed in R1 and R2, respectively. In the second part of the experiment, the efficiency of removal of a toxic substance by aerobic granules was investigated using aniline as a carbon source with a concentration in the range 1.2-6.6 kg COD/m3.d and 1.44-7.92 kg COD/m3.d in R1 and R2, respectively. It was found that COD removal efficiency of the novel airlift reactor was over 97% and 94.5% using glucose and aniline as carbon sources, respectively. Sludge volume index (SVI) was also decreased to 30 mL/g by granulation in the novel airlift reactor. PMID:23393968

  16. Evaluation of the microbial diversity of denitrifying bacteria in batch reactor

    Directory of Open Access Journals (Sweden)

    S. I. Maintinguer

    2013-09-01

    Full Text Available Microbial communities in an industrial activated sludge plant may contribute to the denitrification process, but the information on the microorganisms present in denitrifying reactors is still scarce. Removal of inorganic nitrogen compounds can be accomplished by the addition of carbon sources to the biological process of denitrification. Ethanol is an economically viable alternative as a carbon source in tropical countries like Brazil, with large-scale production from sugarcane. This paper reports the successful aplication of activated sludge with nitrate and ethanol in a batch anaerobic reactor. The operation lasted 61.5 h with total consumption of nitrate in 42.5 h, nitrite generation (2.0 mg/L and ethanol consumption (830.0 mg/L in 23.5 h. Denitrifying cell counts by the most probable number at the start of the operation were lower than at the end, confirming the ability of the inoculum from activated sludge for the denitrification process. The samples from cell counts were identified as Acidovorax sp., Acinetobacter sp., Comamonas sp. and uncultured bacteria. Therefore, these species may be involved in nitrate reduction and ethanol consumption in the batch reactor.

  17. Biodegradation of p-cresol by aerobic granules in sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    Farrukh Basheer; I.H.Farooqi

    2012-01-01

    The cultivation of aerobic granules in sequencing batch reactor for the biodegradation of p-cresol was studied.The reactor was started with 100 mg/L of p-cresol.Aerobic granules first appeared within one month of start up.The granules were large and strong and had a compact structure.The diameter of stable granules was in the range of 1-5 mm.The integrity coefficient and granules density was found to be 96% and 1046 kg/m3,respectively.The settling velocity of granules was found to be in the range of 2×10-2-6×10-2 m/sec.The aerobic granules were able to degrade p-cresol upto 800 mg/L at a removal efficiency of 88%.Specific p-cresol degradation rate in aerobic granules followed Haldane model for substrate inhibition.High specific p-cresol degradation rate up to 0.96 g pcresol/(g VSS.day) were sustained upto p-cresol concentration of 400 mg/L.Higher removal efficiency,good settling characteristics of aerobic granules,makes sequencing batch reactor suitable for enhancing the microorganism potential for biodegradation of inhibitory compounds.

  18. Degradation of estrogens by laccase from Myceliophthora thermophila in fed-batch and enzymatic membrane reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lloret, L. [Dept. of Chemical Engineering, School of Engineering, University of Santiago de Compostela, E-15782 Santiago de Compostela (Spain); Eibes, G., E-mail: gemma.eibes@usc.es [Dept. of Chemical Engineering, School of Engineering, University of Santiago de Compostela, E-15782 Santiago de Compostela (Spain); Feijoo, G.; Moreira, M.T.; Lema, J.M. [Dept. of Chemical Engineering, School of Engineering, University of Santiago de Compostela, E-15782 Santiago de Compostela (Spain)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer Estrogen removal was optimized in fed-batch bioreactors by evaluating the effect of the main process parameters. Black-Right-Pointing-Pointer An enzyme membrane bioreactor (EMR) was proposed for the continuous degradation of estrogens. Black-Right-Pointing-Pointer Estrone was degraded up to 95% and estradiol was not detected in the effluent of the EMR under steady state conditions. Black-Right-Pointing-Pointer The residual estrogenic activity of the effluent was largely reduced up to 97%. - Abstract: Several studies reported that natural and synthetic estrogens are the major contributors to the estrogenic activity associated with the effluents of wastewater treatment plants. The ability of the enzyme laccase to degrade these compounds in batch experiments has been demonstrated in previous studies. Nevertheless, information is scarce regarding in vitro degradation of estrogens in continuous enzymatic bioreactors. The present work constitutes an important step forward for the implementation of an enzymatic reactor for the continuous removal of estrone (E1) and estradiol (E2) by free laccase from Myceliophthora thermophila. In a first step, the effect of the main process parameters (pH, enzyme level, gas composition (air or oxygen) and estrogen feeding rate) were evaluated in fed-batch bioreactors. E1 and E2 were oxidized by 94.1 and 95.5%, respectively, under the best conditions evaluated. Thereafter, an enzymatic membrane reactor (EMR) was developed to perform the continuous degradation of the estrogens. The configuration consisted of a stirred tank reactor coupled with an ultrafiltration membrane, which allowed the recovery of enzyme while both estrogens and degradation products could pass through it. The highest removal rates at steady state conditions were up to 95% for E1 and nearly complete degradation for E2. Furthermore, the residual estrogenic activity of the effluent was largely reduced up to 97%.

  19. Degradation of estrogens by laccase from Myceliophthora thermophila in fed-batch and enzymatic membrane reactors

    International Nuclear Information System (INIS)

    Highlights: ► Estrogen removal was optimized in fed-batch bioreactors by evaluating the effect of the main process parameters. ► An enzyme membrane bioreactor (EMR) was proposed for the continuous degradation of estrogens. ► Estrone was degraded up to 95% and estradiol was not detected in the effluent of the EMR under steady state conditions. ► The residual estrogenic activity of the effluent was largely reduced up to 97%. - Abstract: Several studies reported that natural and synthetic estrogens are the major contributors to the estrogenic activity associated with the effluents of wastewater treatment plants. The ability of the enzyme laccase to degrade these compounds in batch experiments has been demonstrated in previous studies. Nevertheless, information is scarce regarding in vitro degradation of estrogens in continuous enzymatic bioreactors. The present work constitutes an important step forward for the implementation of an enzymatic reactor for the continuous removal of estrone (E1) and estradiol (E2) by free laccase from Myceliophthora thermophila. In a first step, the effect of the main process parameters (pH, enzyme level, gas composition (air or oxygen) and estrogen feeding rate) were evaluated in fed-batch bioreactors. E1 and E2 were oxidized by 94.1 and 95.5%, respectively, under the best conditions evaluated. Thereafter, an enzymatic membrane reactor (EMR) was developed to perform the continuous degradation of the estrogens. The configuration consisted of a stirred tank reactor coupled with an ultrafiltration membrane, which allowed the recovery of enzyme while both estrogens and degradation products could pass through it. The highest removal rates at steady state conditions were up to 95% for E1 and nearly complete degradation for E2. Furthermore, the residual estrogenic activity of the effluent was largely reduced up to 97%.

  20. Algal Feedback and Removal Efficiency in a Sequencing Batch Reactor Algae Process (SBAR to Treat the Antibiotic Cefradine.

    Directory of Open Access Journals (Sweden)

    Jianqiu Chen

    Full Text Available Many previous studies focused on the removal capability for contaminants when the algae grown in an unexposed, unpolluted environment and ignored whether the feedback of algae to the toxic stress influenced the removal capability in a subsequent treatment batch. The present research investigated and compared algal feedback and removal efficiency in a sequencing batch reactor algae process (SBAR to remove cefradine. Three varied pollution load conditions (10, 30 and 60 mg/L were considered. Compared with the algal characteristics in the first treatment batch at 10 and 30 mg/L, higher algal growth inhibition rates were observed in the second treatment batch (11.23% to 20.81%. In contrast, algae produced more photosynthetic pigments in response to cefradine in the second treatment batch. A better removal efficiency (76.02% was obtained during 96 h when the alga treated the antibiotic at 60 mg/L in the first treatment batch and at 30 mg/L in the second treatment batch. Additionally, the removal rate per unit algal density was also improved when the alga treated the antibiotic at 30 or 60 mg/L in the first treatment batch, respectively and at 30 mg/L in the second treatment batch. Our result indicated that the green algae were also able to adapt to varied pollution loads in different treatment batches.

  1. Sequencing batch reactor operation for treating wastewater with aerobic granular sludge

    Directory of Open Access Journals (Sweden)

    M. K. Jungles

    2014-03-01

    Full Text Available In this work, the performance of a sequencing batch reactor (SBR on aerobic granular sludge was studied for urban wastewater treatment. The system was inoculated with aerobic activated sludge collected from a wastewater treatment plant and, after 30 days of operation, the first granules observed had an average diameter of 0.1 mm. The biomass concentration reached a maximum value around 4 g VSS L-1, and COD removal and nitrification efficiency achieved stable values of 90%. The predominant oxidizing ammonium bacteria in the granules were identified as Nitrosomonas spp.

  2. Hydrolysis of Virgin Coconut Oil Using Immobilized Lipase in a Batch Reactor

    OpenAIRE

    Lee Suan Chua; Meisam Alitabarimansor; Chew Tin Lee; Ramli Mat

    2012-01-01

    Hydrolysis of virgin coconut oil (VCO) had been carried out by using an immobilised lipase from Mucor miehei (Lipozyme) in a water-jacketed batch reactor. The kinetic of the hydrolysis was investigated by varying the parameters such as VCO concentration, enzyme loading, water content, and reaction temperature. It was found that VCO exhibited substrate inhibition at the concentration more than 40% (v/v). Lipozyme also achieved the highest production of free fatty acids, 4.56 mM at 1% (w/v) of ...

  3. The capacity of batch reactor optimation for mesophase from tarpitch based on fixed carbon and temperature dynamic analysis

    International Nuclear Information System (INIS)

    The process steps fiber graphite production with tarpitch as raw material are mesophase forming from tar pitch, fiber forming, carbon fiber forming and graphitization of fiber. The mesophase forming at 400 - 550°C so fixed carbon on the mesophase was getting 99.15 % from 98.9 % as fixed carbon on tar pitch. The first step of optimation is identification of graphite fiber capacity production with mesophase reactor capacity. The selection some mesophase reactor capacity, which is optimal, based on value change study of heating utility technical coefficient. The heating utility technical coefficient are Uc (overall heat transfer coefficient of clean condition), Ud (overall heat transfer coefficient of design) and Ar area of heat transfer in the mesophase reactor ). The result of calculation, more higher mesophase reactor capacity so the Uc is bigger but it is not for Ud dan Ar. The Ud dan Ar are effluence with the design condition. Based on the dynamic analysis for selected reactor 132,68 Ib/batch, 199 Ib/batch, 265 Ib/batch and 397,98 Ib/batch. The optimal capacity of mesophase reactor is 265 Ib/batch, it means plant capacity graphite fiber 100 ton/year. The dynamic analysis based on mass balance mathematical model and heat balance mathematical model. The numerical solution use matlab program. (author)

  4. Anaerobic sequencing batch reactor in pilot scale for treatment of tofu industry wastewater

    Science.gov (United States)

    Rahayu, Suparni Setyowati; Purwanto, Budiyono

    2015-12-01

    The small industry of tofu production process releases the waste water without being processed first, and the wastewater is directly discharged into water. In this study, Anaerobic Sequencing Batch Reactor in Pilot Scale for Treatment of Tofu Industry was developed through an anaerobic process to produce biogas as one kind of environmentally friendly renewable energy which can be developed into the countryside. The purpose of this study was to examine the fundamental characteristics of organic matter elimination of industrial wastewater with small tofu effective method and utilize anaerobic active sludge with Anaerobic Sequencing Bath Reactor (ASBR) to get rural biogas as an energy source. The first factor is the amount of the active sludge concentration which functions as the decomposers of organic matter and controlling selectivity allowance to degrade organic matter. The second factor is that HRT is the average period required substrate to react with the bacteria in the Anaerobic Sequencing Bath Reactor (ASBR).The results of processing the waste of tofu production industry using ASBR reactor with active sludge additions as starter generates cumulative volume of 5814.4 mL at HRT 5 days so that in this study it is obtained the conversion 0.16 L of CH4/g COD and produce biogas containing of CH4: 81.23% and CO2: 16.12%. The wastewater treatment of tofu production using ASBR reactor is able to produce renewable energy that has economic value as well as environmentally friendly by nature.

  5. Anaerobic sequencing batch reactor in pilot scale for treatment of tofu industry wastewater

    International Nuclear Information System (INIS)

    The small industry of tofu production process releases the waste water without being processed first, and the wastewater is directly discharged into water. In this study, Anaerobic Sequencing Batch Reactor in Pilot Scale for Treatment of Tofu Industry was developed through an anaerobic process to produce biogas as one kind of environmentally friendly renewable energy which can be developed into the countryside. The purpose of this study was to examine the fundamental characteristics of organic matter elimination of industrial wastewater with small tofu effective method and utilize anaerobic active sludge with Anaerobic Sequencing Bath Reactor (ASBR) to get rural biogas as an energy source. The first factor is the amount of the active sludge concentration which functions as the decomposers of organic matter and controlling selectivity allowance to degrade organic matter. The second factor is that HRT is the average period required substrate to react with the bacteria in the Anaerobic Sequencing Bath Reactor (ASBR).The results of processing the waste of tofu production industry using ASBR reactor with active sludge additions as starter generates cumulative volume of 5814.4 mL at HRT 5 days so that in this study it is obtained the conversion 0.16 L of CH4/g COD and produce biogas containing of CH4: 81.23% and CO2: 16.12%. The wastewater treatment of tofu production using ASBR reactor is able to produce renewable energy that has economic value as well as environmentally friendly by nature

  6. Anaerobic sequencing batch reactor in pilot scale for treatment of tofu industry wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Rahayu, Suparni Setyowati, E-mail: suparnirahayu@yahoo.co.id [Doctoral Program in Environmental Science, University of Diponegoro, Semarang (Indonesia); Department of Mechanical Engineering, State Polytechnic of Semarang, Semarang Indonesia (Indonesia); Purwanto,, E-mail: p.purwanto@che.undip.ac.id; Budiyono, E-mail: budiyono@live.undip.ac.id [Doctoral Program in Environmental Science, University of Diponegoro, Semarang (Indonesia); Department of Chemical Engineering, Faculty of Engineering, Diponegoro University, Semarang Indonesia (Indonesia)

    2015-12-29

    The small industry of tofu production process releases the waste water without being processed first, and the wastewater is directly discharged into water. In this study, Anaerobic Sequencing Batch Reactor in Pilot Scale for Treatment of Tofu Industry was developed through an anaerobic process to produce biogas as one kind of environmentally friendly renewable energy which can be developed into the countryside. The purpose of this study was to examine the fundamental characteristics of organic matter elimination of industrial wastewater with small tofu effective method and utilize anaerobic active sludge with Anaerobic Sequencing Bath Reactor (ASBR) to get rural biogas as an energy source. The first factor is the amount of the active sludge concentration which functions as the decomposers of organic matter and controlling selectivity allowance to degrade organic matter. The second factor is that HRT is the average period required substrate to react with the bacteria in the Anaerobic Sequencing Bath Reactor (ASBR).The results of processing the waste of tofu production industry using ASBR reactor with active sludge additions as starter generates cumulative volume of 5814.4 mL at HRT 5 days so that in this study it is obtained the conversion 0.16 L of CH{sub 4}/g COD and produce biogas containing of CH{sub 4}: 81.23% and CO{sub 2}: 16.12%. The wastewater treatment of tofu production using ASBR reactor is able to produce renewable energy that has economic value as well as environmentally friendly by nature.

  7. Removal performance and microbial communities in a sequencing batch reactor treating hypersaline phenol-laden wastewater.

    Science.gov (United States)

    Jiang, Yu; Wei, Li; Zhang, Huining; Yang, Kai; Wang, Hongyu

    2016-10-01

    Hypersaline phenol-rich wastewater is hard to be treated by traditional biological systems. In this work, a sequencing batch reactor was used to remove phenol from hypersaline wastewater. The removal performance was evaluated in response to the variations of operating parameters and the microbial diversity was investigated by 454 pyrosequencing. The results showed that the bioreactor had high removal efficiency of phenol and was able to keep stable with the increase of initial phenol concentration. DO, pH, and salinity also affected the phenol removal rate. The most abundant bacterial group was phylum Proteobacteria in the two working conditions, and class Gammaproteobacteria as well as Alphaproteobacteria was predominant subgroup. The abundance of bacterial clusters was notably different along with the variation of operation conditions, resulting in changes of phenol degradation rates. The high removal efficiency of phenol suggested that the reactor might be promising in treating phenol-laden industrial wastewater in high-salt condition. PMID:27359064

  8. Biomass characteristics in three sequencing batch reactors treating a wastewater containing synthetic organic chemicals

    DEFF Research Database (Denmark)

    Hu, Z.Q.; Ferraina, R.A.; Ericson, J.F.;

    2005-01-01

    The physical and biochemical characteristics of the biomass in three lab-scale sequencing batch reactors (SBR) treating a synthetic wastewater at a 20-day target solids retention time (SRT) were investigated. The synthetic wastewater feed contained biogenic compounds and 22 organic priming...... compounds, chosen to represent a wide variety of chemical structures with different N, P and S functional groups. At a two-day hydraulic retention time (HRT), the oxidation-reduction potential (ORP) cycled between -100 (anoxic) and 100mV (aerobic) in the anoxic/aerobic SBR, while it remained in a range of...... all reactors. In contrast, effluent 3-nitrobenzoate was recorded when its influent concentration was increased to 5 mg L-1 and dropped only to below 1 mg L-1 after 300 days of operation. The competent (active) biomass fractions for these compounds were between 0.04% and 5.52% of the total biomass...

  9. Microbial population dynamics during sludge granulation in an A/O/A sequencing batch reactor.

    Science.gov (United States)

    He, Qiulai; Zhou, Jun; Wang, Hongyu; Zhang, Jing; Wei, Li

    2016-08-01

    The evolution of the bacterial population during formation of denitrifying phosphorus removal granular sludge was investigated using high-throughput pyrosequencing. As a result, mature granules with a compact structure were obtained in an anaerobic/aerobic/anoxic (A/O/A) sequencing batch reactor under an organic loading rate as low as 0.3kg COD/(m(3)·d). Rod-shaped microbes were observed to cover with the outer surface of granules. Besides, reliable COD and simultaneous nitrogen and phosphorus removal efficiencies were achieved over the whole operation period. MiSeq pyrosequencing analysis illustrated that both the microbial diversity and richness increased sharply during the granulation process, whereas they stayed stable after the presence of granules. Some microorganisms seemed to contribute to the formation of granules, and some were identified as functional bacterial groups responsible for constructing the biological reactor. PMID:27115745

  10. The Denitrifying Biological Phosphorus Removal Performance in Anaerobic/Anoxic Sequencing Batch Reactor: The Effect of Carbon Source

    OpenAIRE

    Gürtekin, Engin; Nusret ŞEKERDAĞ

    2015-01-01

    In this study, the effect of carbon source on denitrifying biological phosphorus removal performance in acetate and glucose fed two anaerobic/anoxic sequencinq batch reactor (SBR) was investigated. Glucose and acetate were used as the substrates. In acetate and glucose fed reactors, the COD (Chemical Oxygen Demand) removal efficiencies were 91,90% and PO4-P removal efficiencies were 87,51% respectively. These results shows that the phosphorus removal efficiency is lower in glucose fed reactor.

  11. 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.

  12. Aerobic biodegradation of a mixture of monosubstituted phenols in a sequencing batch reactor

    International Nuclear Information System (INIS)

    Highlights: • Aerobic biodegradation of a mixture of p-nitrophenol and o-cresol is feasible. • Simultaneous biodegradation of p-nitrophenol and o-cresol was achieved at long-term. • o-Chlorophenol caused complete failure of the sequencing batch reactor. • Biomass had good settling properties although no mature granules were obtained. • p-Nitrophenol is believed to be responsible for granulation failure. -- Abstract: A sequencing batch reactor (SBR) was inoculated with p-nitrophenol-degrading activated sludge to biodegrade a mixture of monosubstituted phenols: p-nitrophenol (PNP), PNP and o-cresol; and PNP, o-cresol and o-chlorophenol. Settling times were progressively decreased to promote biomass granulation. PNP was completely biodegraded. The PNP and o-cresol mixture was also biodegraded although some transitory accumulation of intermediates occurred (mainly hydroquinone and catechol). o-Chlorophenol was not biodegraded and resulted in inhibition of o-cresol and PNP biodegradation and complete failure of the SBR within a few days. The biomass had very good settling properties when a settling time of 1 min was applied: sludge volume index (SVI5) below 50 mL g−1, SVI5/SVI30 ratio of 1 and average particle size of 200 μm

  13. Effect of redox conditions on pharmaceutical loss during biological wastewater treatment using sequencing batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Stadler, Lauren B., E-mail: lstadler@umich.edu [Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109 (United States); Su, Lijuan, E-mail: lijuansu@buffalo.edu [Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260 (United States); Moline, Christopher J., E-mail: christopher.moline@hdrinc.com [Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109 (United States); Ernstoff, Alexi S., E-mail: alexer@dtu.dk [Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109 (United States); Aga, Diana S., E-mail: dianaaga@buffalo.edu [Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY 14260 (United States); Love, Nancy G., E-mail: nglove@umich.edu [Department of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE, Ann Arbor, MI 48109 (United States)

    2015-01-23

    Highlights: • Pharmaceutical fate was studied in SBRs operated at different redox conditions. • Stable carbon oxidation and nitrification occurred under microaerobic conditions. • Losses of atenolol and trimethoprim were highest under fully aerobic conditions. • Loss of sulfamethoxazole was highest under microaerobic conditions. • Deconjugation occurred during treatment to form sulfamethoxazole and desvenlafaxine. - Abstract: We lack a clear understanding of how wastewater treatment plant (WWTP) process parameters, such as redox environment, impact pharmaceutical fate. WWTPs increasingly install more advanced aeration control systems to save energy and achieve better nutrient removal performance. The impact of redox condition, and specifically the use of microaerobic (low dissolved oxygen) treatment, is poorly understood. In this study, the fate of a mixture of pharmaceuticals and several of their transformation products present in the primary effluent of a local WWTP was assessed in sequencing batch reactors operated under different redox conditions: fully aerobic, anoxic/aerobic, and microaerobic (DO concentration ≈0.3 mg/L). Among the pharmaceuticals that were tracked during this study (atenolol, trimethoprim, sulfamethoxazole, desvenlafaxine, venlafaxine, and phenytoin), overall loss varied between them and between redox environments. Losses of atenolol and trimethoprim were highest in the aerobic reactor; sulfamethoxazole loss was highest in the microaerobic reactors; and phenytoin was recalcitrant in all reactors. Transformation products of sulfamethoxazole and desvenlafaxine resulted in the reformation of their parent compounds during treatment. The results suggest that transformation products must be accounted for when assessing removal efficiencies and that redox environment influences the degree of pharmaceutical loss.

  14. Effect of redox conditions on pharmaceutical loss during biological wastewater treatment using sequencing batch reactors

    International Nuclear Information System (INIS)

    Highlights: • Pharmaceutical fate was studied in SBRs operated at different redox conditions. • Stable carbon oxidation and nitrification occurred under microaerobic conditions. • Losses of atenolol and trimethoprim were highest under fully aerobic conditions. • Loss of sulfamethoxazole was highest under microaerobic conditions. • Deconjugation occurred during treatment to form sulfamethoxazole and desvenlafaxine. - Abstract: We lack a clear understanding of how wastewater treatment plant (WWTP) process parameters, such as redox environment, impact pharmaceutical fate. WWTPs increasingly install more advanced aeration control systems to save energy and achieve better nutrient removal performance. The impact of redox condition, and specifically the use of microaerobic (low dissolved oxygen) treatment, is poorly understood. In this study, the fate of a mixture of pharmaceuticals and several of their transformation products present in the primary effluent of a local WWTP was assessed in sequencing batch reactors operated under different redox conditions: fully aerobic, anoxic/aerobic, and microaerobic (DO concentration ≈0.3 mg/L). Among the pharmaceuticals that were tracked during this study (atenolol, trimethoprim, sulfamethoxazole, desvenlafaxine, venlafaxine, and phenytoin), overall loss varied between them and between redox environments. Losses of atenolol and trimethoprim were highest in the aerobic reactor; sulfamethoxazole loss was highest in the microaerobic reactors; and phenytoin was recalcitrant in all reactors. Transformation products of sulfamethoxazole and desvenlafaxine resulted in the reformation of their parent compounds during treatment. The results suggest that transformation products must be accounted for when assessing removal efficiencies and that redox environment influences the degree of pharmaceutical loss

  15. Denitrifying capability and community dynamics of glycogen accumulating organisms during sludge granulation in an anaerobic-aerobic sequencing batch reactor

    OpenAIRE

    Zhang Bin; Xue Bin; Qiu Zhigang; Chen Zhiqiang; Li Junwen; Gong Taishi; Zou Wenci; Wang Jingfeng

    2015-01-01

    Denitrifying capability of glycogen accumulating organisms (GAOs) has received great attention in environmental science and microbial ecology. Combining this ability with granule processes would be an interesting attempt. Here, a laboratory-scale sequencing batch reactor (SBR) was operated to enrich GAOs and enable sludge granulation. The results showed that the GAO granules were cultivated successfully and the granules had denitrifying capability. The batch experiments demonstrated that all ...

  16. Algal Feedback and Removal Efficiency in a Sequencing Batch Reactor Algae Process (SBAR) to Treat the Antibiotic Cefradine

    OpenAIRE

    Chen, Jianqiu; Zheng, Fengzhu; Guo, Ruixin

    2015-01-01

    Many previous studies focused on the removal capability for contaminants when the algae grown in an unexposed, unpolluted environment and ignored whether the feedback of algae to the toxic stress influenced the removal capability in a subsequent treatment batch. The present research investigated and compared algal feedback and removal efficiency in a sequencing batch reactor algae process (SBAR) to remove cefradine. Three varied pollution load conditions (10, 30 and 60 mg/L) were considered. ...

  17. 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

  18. Aerobic degradation of ibuprofen in batch and continuous reactors by an indigenous bacterial community.

    Science.gov (United States)

    Fortunato, María Susana; Fuentes Abril, Nancy Piedad; Martinefski, Manuela; Trípodi, Valeria; Papalia, Mariana; Rádice, Marcela; Gutkind, Gabriel; Gallego, Alfredo; Korol, Sonia Edith

    2016-10-01

    Water from six points from the Riachuelo-Matanza basin was analyzed in order to assess ibuprofen biodegradability. In four of them biodegradation of ibuprofen was proved and degrading bacterial communities were isolated. Biodegradation in each point could not be correlated with sewage pollution. The indigenous bacterial community isolated from the point localized in the La Noria Bridge showed the highest degradative capacity and was selected to perform batch and continuous degradation assays. The partial 16S rRNA gene sequence showed that the community consisted of Comamonas aquatica and Bacillus sp. In batch assays the community was capable of degrading 100 mg L(-1) of ibuprofen in 33 h, with a specific growth rate (μ) of 0.21 h(-1). The removal of the compound, as determined by High performance liquid chromatography (HPLC), exceeded 99% of the initial concentration, with a 92.3% removal of Chemical Oxygen Demand (COD). In a down-flow fixed-bed continuous reactor, the community shows a removal efficiency of 95.9% of ibuprofen and 92.3% of COD for an average inlet concentration of 110.4 mg. The reactor was kept in operation for 70 days. The maximal removal rate for the compound was 17.4 g m(-3) d(-1). Scanning electron microscopy was employed to observe biofilm development in the reactor. The ability of the isolated indigenous community can be exploited to improve the treatment of wastewaters containing ibuprofen. PMID:26905769

  19. Bioaugmentation of a sequencing batch reactor with Pseudomonas putida ONBA-17, and its impact on reactor bacterial communities

    International Nuclear Information System (INIS)

    This study demonstrates the feasibility of using Pseudomonasputida ONBA-17 to bioaugment a sequencing batch reactor (SBR) treating o-nitrobenzaldehyde (ONBA) synthetic wastewater. To monitor its survival, the strain was chromosomally marked with gfp gene. After a transient adaptation, almost 100% degradation of ONBA was obtained within 8 days as compared with 23.47% of the non-inoculated control. The bioaugmented reactor has a better chemical oxygen demand (COD) removal performance (96.28%) than that (79.26%) of the control. The bioaugmentation not only enhanced the removal capability of target compound, but shortened system start-up time. After the increase in ONBA load, performance fluctuation of two reactors was observed, and the final treating effects of them were comparable. What is more, denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA genes via a combination of pattern comparison and sequence phylogenetic analysis was performed to uncover changes in sludge microbial communities. Only the members of alpha, beta and gamma subdivisions of Proteobacteria were identified. To isolate ONBA-degrading relevant microorganisms, spread plate was used and four bacterial strains were obtained. Subsequent systematic studies on these bacteria characterized their traits which to some extent explained why such bacteria could be kept in the system. This study will help future research in better understanding of the bioreactor bioaugmentation.

  20. Changes in bacterial communities accompanied by aggregation in a fed-batch composting reactor.

    Science.gov (United States)

    Watanabe, Keiko; Nagao, Norio; Toda, Tatsuki; Kurosawa, Norio

    2008-05-01

    The contents of fed-batch composting (FBC) reactors often aggregate after prolonged operation. This process leads to irreversible breakdown of the decomposition reaction and possible alteration of the bacterial communities. We compared the structures of bacterial communities in reactors under aggregate and optimal conditions. The results of 16S rRNA gene clone analysis showed that populations of the family Bacillaceae (such as Bacillus spp., Cerasibacillus spp., Gracilibacillus spp.), which dominate (98%) under optimal condition, were significantly decreased under aggregate condition. In contrast, populations of the family Staphylococcaceae considerably increased after aggregation and accounted for 53% of the total. Phylogenetic analysis also showed that anaerobes or facultative anaerobes related to Tetragenococcus halophilus, Atopostipes suicloacalis, Jeotgalicoccus pinnipedialis, and Staphylococcus spp. were dominant in the aggregates. These results suggested that aerobic Gram-positive bacteria mainly contributed to organic degradation and that aggregation created some anaerobic environment, which promoted the growth of bacterial communities usually not found in well-functioning FBC reactors. PMID:18231830

  1. Design of Mixed Batch Reactor and Column Studies at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Weimin [Stanford Univ., CA (United States); Criddle, Craig S. [Stanford Univ., CA (United States)

    2015-11-16

    We (the Stanford research team) were invited as external collaborators to contribute expertise in environmental engineering and field research at the ORNL IFRC, Oak Ridge, TN, for projects carried out at the Argonne National Laboratory and funded by US DOE. Specifically, we assisted in the design of batch and column reactors using ORNL IFRC materials to ensure the experiments were relevant to field conditions. During the funded research period, we characterized ORNL IFRC groundwater and sediments in batch microcosm and column experiments conducted at ANL, and we communicated with ANL team members through email and conference calls and face-to-face meetings at the annual ERSP PI meeting and national meetings. Microcosm test results demonstrated that U(VI) in sediments was reduced to U(IV) when amended with ethanol. The reduced products were not uraninite but unknown U(IV) complexes associated with Fe. Fe(III) in solid phase was only partially reduced. Due to budget reductions at ANL, Stanford contributions ended in 2011.

  2. Design of Mixed Batch Reactor and Column Studies at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    We (the Stanford research team) were invited as external collaborators to contribute expertise in environmental engineering and field research at the ORNL IFRC, Oak Ridge, TN, for projects carried out at the Argonne National Laboratory and funded by US DOE. Specifically, we assisted in the design of batch and column reactors using ORNL IFRC materials to ensure the experiments were relevant to field conditions. During the funded research period, we characterized ORNL IFRC groundwater and sediments in batch microcosm and column experiments conducted at ANL, and we communicated with ANL team members through email and conference calls and face-to-face meetings at the annual ERSP PI meeting and national meetings. Microcosm test results demonstrated that U(VI) in sediments was reduced to U(IV) when amended with ethanol. The reduced products were not uraninite but unknown U(IV) complexes associated with Fe. Fe(III) in solid phase was only partially reduced. Due to budget reductions at ANL, Stanford contributions ended in 2011.

  3. Biological treatment of PAH-contaminated sediments in a Sequencing Batch Reactor

    International Nuclear Information System (INIS)

    The technical feasibility of a sequential batch process for the biological treatment of sediments contaminated by polycyclic aromatic hydrocarbons (PAHs) was evaluated through an experimental study. A bench-scale Sediment Slurry Sequencing Batch Reactor (SS-SBR) was fed with river sediments contaminated by a PAH mixture made by fluorene, anthracene, pyrene and crysene. The process performance was evaluated under different operating conditions, obtained by modifying the influent organic load, the feed composition and the hydraulic residence time. Measurements of the Oxygen Uptake Rates (OURs) provided useful insights on the biological kinetics occurring in the SS-SBR, suggesting the minimum applied cycle time-length of 7 days could be eventually halved, as also confirmed by the trend observed in the volatile solid and total organic carbon data. The removal efficiencies gradually improved during the SS-SBR operation, achieving at the end of the study rather constant removal rates above 80% for both 3-rings PAHs (fluorene and anthracene) and 4-ring PAHs (pyrene and crysene) for an inlet total PAH concentration of 70 mg/kg as dry weight (dw).

  4. Correspondence between Community Structure and Function during Succession in Phenol- and Phenol-plus-Trichloroethene-Fed Sequencing Batch Reactors

    OpenAIRE

    Ayala-del-Río, Héctor L.; Stephen J Callister; Criddle, Craig S.; Tiedje, James M

    2004-01-01

    The effects of more than 2 years of trichloroethene (TCE) application on community succession and function were studied in two aerobic sequencing batch reactors. One reactor was fed phenol, and the second reactor was fed both phenol and TCE in sequence twice per day. After initiation of TCE loading in the second reactor, the TCE transformation rates initially decreased, but they stabilized with an average second-order rate coefficient of 0.044 liter mg−1 day−1 for 2 years. In contrast, the ph...

  5. Hydrodesulfurization of light gas oil: Kinetic determination in a batch reactor

    Directory of Open Access Journals (Sweden)

    Skala Dejan U.

    2002-01-01

    Full Text Available The performed investigations were directed toward the analysis of the performance and activity of the fresh and regenerated Cyanamid HDS 20C catalyst in a laboratory batch reactor (2 dm3 for the HDS of the diesel fraction (light gas oil, LGO. Testing of the regenerated catalyst was performed with light gas oil (LGO of different characteristics. The determined values of the reaction rate constant were compared to some published data in the literature for the HDS of specific sulfur compounds as well as the values of the activation energy. The rates of deactivation of the fresh and regenerated catalyst actually existed compared to some other results recently published in the literature. However, such an observed differences were not sufficient to derive a relation which could be used for the determination of the rate of catalyst deactivation.

  6. Experimental and modeling analysis of a batch gasification/pyrolysis reactor

    International Nuclear Information System (INIS)

    This paper presents some experimental results about biomass gasification obtained with a bench-scale gasifier consisting of an indirectly heated batch reactor, inserted in a high temperature furnace. Spruce wood has been used as feedstock in different forms and sizes (as pellets and sawdust). The experimental activity includes the analysis of the thermal response of the system (using an inert bed material) and the characterization of the gasification products. The yield of the gaseous compounds found in the syngas has been measured using an on-line gas-chromatography technique. The experimental results have been compared against calculations obtained by applying a thermochemical equilibrium model, improved to predict both the gas and the solid phase product yields. The experimental (average) yield of reaction products has been found to be in a satisfying agreement with the thermodynamic model.

  7. Chloro-Organics in Papermill Effluent: Identification and Removal by Sequencing Batch Biofilm Reactor

    Science.gov (United States)

    Abd. Rahman, Rakmi; Zahrim, A. Y.; Abu Bakar, Azizah

    Effluents from paper mills are among major sources of aquatic pollution and may be toxic since they contain chlorinated phenolic compounds which are measured as adsorbable organic halides (AOX). In this work, removal of chlorophenol was investigated using a Sequencing Batch Biofilm Reactor (SBBR) with Granular Activated Carbon (GAC) as a growth media. Wastewater for this study was obtained from treated effluent outlet of a papermill in Selangor. Treatment of the papermill secondary effluent shows that SBBR process, with a combination of adsorption and biodegradation, gave a good removal of pentachlorophenol (PCP), on average, about 70%. The growth kinetic parameters obtained were: YH = 0.6504 mg biomass/mg PCP, dH = 6.50x10-5 h-1, μh = 0.00315 h-1 and Ks = 5.82 mg PCP L-1. These show that the SBBR system is suitable to be operated at long SRTs.

  8. Combined treatment of landfill leachate with fecal supernatant in sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shao-qi; ZHANG Hong-guo; SHI Yong

    2006-01-01

    A laboratory-scale sequencing batch reactor (SBR) is used to treat landfill leachate containing high concentration of ammonium nitrogen with municipal fecal supernatant. The SBR system is operated in the following sequential phases: fill period,anoxic period, aeration period, settling period, decant and idle period. The results indicated that the average removal efficiencies of COD, BOD5, TN, NH+4-N were 93.76%, 98.28%, 84.74% and 99.21%, respectively. The average sludge removal loading rates of Highly effective simultaneous nitrification and denitrification was achieved in the SBR system. The ratio of nitrification and denitrification was 99% and 84%, respectively. There was partial NO-2 denitrification in the system.

  9. Decolorization of Orange Ⅱ using an anaerobic sequencing batch reactor with and without co-substrates

    Institute of Scientific and Technical Information of China (English)

    Soon-An Ong; Eiichi Toorisaka; Makoto Hirata; Tadashi Hano

    2012-01-01

    We investigated the decolorization of Orange Ⅱ with and without the addition of co-substrates and nutrients under an anaerobic sequencing batch reactor (ASBR).The increase in COD concentrations from 900 to 1750 to 3730 mg/L in the system treating 100 mg/L of Orange H-containing wastewater enhanced color removal from 27% to 81% to 89%,respectively.In the absence of co-substrates and nutrients,more than 95% of decolorization was achieved by the acclimatized anaerobic microbes in the bioreactor treating 600 mg/L of Orange Ⅱ.The decrease in mixed liquor suspended solids concentration by endogenous lysis of biomass preserved a high reducing environment in the ASBR,which was important for the reduction of the Orange Ⅱ azo bond that caused decolorization.The maximum decolorization rate in the ASBR was approximately 0.17 g/hr in the absence of co-substrates and nutrients.

  10. Aerobic digestion of tannery wastewater in a sequential batch reactor by salt-tolerant bacterial strains

    Science.gov (United States)

    Durai, G.; Rajasimman, M.; Rajamohan, N.

    2011-09-01

    Among the industries generating hyper saline effluents, tanneries are prominent in India. Hyper saline wastewater is difficult to treat by conventional biological treatment methods. Salt-tolerant microbes can adapt to these conditions and degrade the organics in hyper saline wastewater. In this study, the performance of a bench scale aerobic sequencing batch reactor (SBR) was investigated to treat the tannery wastewater by the salt-tolerant bacterial strains namely Pseudomonas aeruginosa, Bacillus flexus, Exiguobacterium homiense and Styphylococcus aureus. The study was carried out under different operating conditions by changing the hydraulic retention time, organic loading rate and initial substrate concentration. From the results it was found that a maximum COD reduction of 90.4% and colour removal of 78.6% was attained. From this study it was found that the salt-tolerant microorganisms could improve the reduction efficiency of COD and colour of the tannery wastewater.

  11. ANAEROBIC-AEROBIC TREATMENT OF TEXTILE WASTEWATER IN A SEQUENCING BATCH REACTOR

    Directory of Open Access Journals (Sweden)

    IBTISSAM KANBOUCHI

    2014-04-01

    Full Text Available In this work, the treatment of synthetic textile wastewater using sequential batch reactor (SBR was studied. This in order to predict the effectiveness of biological treatment on wastewater containing dyes while minimizing the aeration cost. Laboratory tests were performed on synthetic wastewater containing filtered urban wastewater (source of bacteria and dyes solutions. This promotes the biomass development in the mixture, capable of degrading organic matter properly. The results indicate that the increasing of anaerobic phase (16 hours allows removal of 77 % and 80 % of COD and colour, respectively. The sludge age did not affect markedly dyes biodegradability. However, the biodegradability is strongly influenced by the dyes concentration. Indeed, for the lowest dyes contents, improved biodegradability was observed, while it decreases when the dyes concentration increases.

  12. Factors affecting biological denitrifying dephosphatation in anaerobic/anoxic/aerobic sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This study was conducted to verify and discuss the denitrifying dephosphatation under different levels of nitrate concentration and retention time of anoxic/aerobic process in a Sequencing Batch Reactor ( SBR ).The results of tests demonstrated that there were two kinds of phosphorus-accumulating organisms (PAOs) in the biological excess phosphorus removal (BEPR) system. One was non-DNPAOs that could only use oxygen as terminal electron acceptors, the other was denitrifying PAOs (DNPAOs) that could use both nitrate and oxygen as terminal electron acceptors. Phosphorus uptake efficiency could be attained under anoxic period ranging from 28.7%-96.7% in an anacrobic/anoxic/aerobic system. Experimental results showed that nitrate concentration and retention time of anoxic/aerobic process were the key factors affecting the course of denitrifying dephosphatation.

  13. Effect of redox conditions on pharmaceutical loss during biological wastewater treatment using sequencing batch reactors

    DEFF Research Database (Denmark)

    Stadler, Lauren B.; Su, Lijuan; Moline, Christopher J.;

    2015-01-01

    We lack a clear understanding of how wastewater treatment plant (WWTP) process parameters, such as redox environment, impact pharmaceutical fate. WWTPs increasingly install more advanced aeration control systems to save energy and achieve better nutrient removal performance. The impact of redox...... condition, and specifically the use of microaerobic (low dissolved oxygen) treatment, is poorly understood. In this study, the fate of a mixture of pharmaceuticals and several of their transformation products present in the primary effluent of a local WWTP was assessed in sequencing batch reactors operated...... their parent compounds during treatment. The results suggest that transformation products must be accounted for when assessing removal efficiencies and that redox environment influences the degree of pharmaceutical loss....

  14. Temperature control of bench-scaled batch reactor equipped with a monofluid heating/cooling system

    Science.gov (United States)

    Teng, Hai-peng; Song, Yi-ming

    2014-04-01

    An advanced control concept, Predictive Functional Control (PFC), is applied for temperature control of a bench-scaled batch reactor equipped with monofluid heating/cooling system. First principles process models are developed. Based on achieved models, significant process variables, which are difficult or impossible to measure online, are estimated from easily measured variables, and cascade PFC control strategy has been projected and implemented in Matlab R14. The dynamics of individual subunits is explicitly taken into consideration by internal model in the control algorithms, and model uncertainty, various process disturbances are compensated by modification of internal model. The experimental results present an excellent capability of tracking the set point, and the success of PFC technique as a process control paradigm is illustratively demonstrated.

  15. Dynamic modelling of substrate degradation for urban wastewater treatment by sequencing batch reactor

    International Nuclear Information System (INIS)

    This paper presents the dynamic modelling of substrate degradation for urban wastewater treatment by a pilot-scaled sequencing batch reactor including experimental data of a long-term experimental work performed at different operation conditions. During the study, pH, chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) were measured to investigate SBR treatment performance. Optimum operation times were determined and kinetic constant (k) was calculated (0.60 h-1) with using experimental results for urban wastewater. The Model Simulation estimates were very good fit with the experimental data under organic loading degradation conditions model simulation predictions well match with the experimental results under disturbed organic loading conditions. (author)

  16. quarters

    Directory of Open Access Journals (Sweden)

    Elena Grigoryeva

    2016-12-01

    Full Text Available Are there many words combining both space and time? A quarter is one of such rare words: it means both a part of the city space and a period of the year. A regular city has parts bordered by four streets. For example, Chita is a city with an absolutely orthogonal historical center. This Utopian city was designed by Decembrists in the depth of Siberian ore-mines (120. The 130 Quarter in Irkutsk is irregular from its inception because of its triangular form. Located between two roads, the forked quarter was initially bordered by flows along the west-east axis – the main direction of the country. That is why it appreciated the gift for the 350 anniversary of its transit existence – a promenade for an unhurried flow of pedestrians. The quarter manages this flow quite well, while overcoming the difficulties of new existence and gathering myths (102. Arousing many expectations, the “Irkutsk’s Quarters” project continues the theme that was begun by the 130 Quarter and involved regeneration, revival and search for Genius Loci and the key to each single quarter (74. Beaded on the trading axis, these shabby and unfriendly quarters full of rubbish should be transformed for the good of inhabitants, guests and the small business. The triptych by Lidin, Rappaport and Nevlyutov is about happiness of urbanship and cities for people, too (58. The City Community Forum was also devoted to the urban theme (114. Going through the last quarter of the year, we hope that Irkutsk will keep to the right policy, so that in the near future the wooden downtown quarters will become its pride, and the design, construction and investment complexes will join in desire to increase the number of comfortable and lively quarters in our city. The Baikal Beam will get one more landmark: the Smart School (22 for Irkutsk’s children, including orphans, will be built in several years on the bank of Chertugeevsky Bay.

  17. Catalytic stepwise nitrate hydrogenation in batch-recycle fixed-bed reactors

    International Nuclear Information System (INIS)

    Pd (1.0 wt.%)-Cu (0.3 wt.%) bimetallic and Pd (1.0 wt.%) monometallic catalysts were synthesized by means of incipient-wetness impregnation technique and deposited on alumina spheres (dp = 1.7 mm). The prepared catalysts were tested at T = 298 K and p(H2) = 1.0 bar in the integrated process of catalytic liquid-phase hydrogenation of aqueous nitrate solutions, in which the denitration step was carried out consecutively in separate, single-flow fixed-bed reactor units operating in a batch-recycle mode. In the first reactor packed with a Pd-Cu bimetallic catalyst, nitrate ions were transformed to nitrites at pH 12.5 with a selectivity as high as 93%; the rest was found in the form of ammonium ions. Liquid-phase nitrite hydrogenation to nitrogen in the second reactor unit packed with a Pd monometallic catalyst was conducted at low pH values of 3.7 and 4.5, respectively. Although these values are well below the pHpzc of examined catalyst (6.1), which assured that the nitrite reduction was carried out over a positively charged catalyst surface, up to 15% (23% in the presence of 5.0 g/l NaCl in the solution) of initial nitrite content was converted to undesired ammonium ions. Since a negligible amount of these species (below 0.5 mg/l) was produced at identical operating conditions over a powdered Pd/γ-Al2O3 catalyst, it is believed that the enhanced production of ammonium ions observed in the second fixed-bed reactor is due to the build-up of pH gradients in liquid-filled pores of spherical catalyst particles. Both Pd-Cu bimetallic and Pd monometallic catalysts were chemically resistant in the investigated range of pH values

  18. Effect of different carbon sources on the biological phosphorus removal by a sequencing batch reactor using pressurized pure oxygen

    OpenAIRE

    Wei, Jie; Imai, Tsuyoshi; Higuchi, Takaya; Arfarita, Novi; YAMAMOTO, Koichi; Sekine, Masahiko; Kanno, Ariyo

    2014-01-01

    The effect of different carbon source on the efficiency of enhanced biological phosphorus removal (EBPR) from synthetic wastewater with acetate and two ratios of acetate/starch as a carbon source was investigated. Three pressurized pure oxygen sequencing batch reactor (POSBR) experiments were operated. The reactors (POSBR1, POSBR2 and POSBR3) were developed and studied at different carbon source ratios of 100% acetate, 75% acetate plus 25% starch and 50% acetate plus 50% starch, respectively....

  19. Feasibility of a Pulsed Sequencing Batch reactor with anaerobic aggregated biomass for the treatment of low strength wastewaters

    OpenAIRE

    Brito, A. G.; Rodrigues, A.C.; Melo, L. F.

    1997-01-01

    This study concerns an assessment of a SBR operation that associates anaerobic aggregated biomass with a pulsed action during the reaction phase, a system named Pulsed Sequencing Batch Reactor (P-SBR). The system uses a diaphragm pump as a pulsator unit to increase the liquid-solid contact, in order to avoid dead zones and possible external mass transfer resistance. A preliminary study of the operation of the reactor was performed with a low strength synthetic wastewater with a COD near 1000 ...

  20. Methane Production from Solid Potatoes by a Procedure Simulating a Bench-Scale Sequencing Batch Reactor Anaerobic Process

    OpenAIRE

    Colussi, I.; Cortesi, A.; Gallo, V; Rubesa Fernandez, A. S.; Vitanza, R.

    2014-01-01

    In this study, an experimental setup for the evaluation of a two-stage anaerobic digestion has been developed: a laboratory-scale apparatus was assembled employing solid potatoes as energy crops. Two coupled 5-litre batch-fed stirred reactors, one for the hydrolytic-acidogenic step and one for the acetogenic-methanogenic step, kept at mesophilic temperature (308.1 K), were adopted. Evaluated in the first acidogenic reactor was the influence of fermentative yeast (Saccharomyces cerevisiae) on ...

  1. Removal of fluoxetine and its effects in the performance of an aerobic granular sludge sequential batch reactor

    OpenAIRE

    Moreira, Irina S.; Amorim, Catarina L.; Ribeiro, Ana R.; Mesquita, Raquel B. R.; Rangel, António O. S. S.; Van Loosdrecht, Mark C.M.; Tiritan, Maria E.; Castro, Paula M. L.

    2015-01-01

    Fluoxetine (FLX) is a chiral fluorinated pharmaceutical mainly indicated for treatment of depression and is one of the most distributed drugs. There is a clear evidence of environmental contamination with this drug. Aerobic granular sludge sequencing batch reactors constitute a promising technology for wastewater treatment; however the removal of carbon and nutrients can be affected by micropollutants. In this study, the fate and effect of FLX on reactor performance and on microbi...

  2. Anaerobic Removal of Ammonia Nitrogen by an Autotrophic Reactor with Fixed Film Opering in a Sequential Batch

    OpenAIRE

    Murilo C. Lucas; José H. A. Vasconcelos; Francisco Javier Cuba Téran; Carla Eloísa Diniz dos Santos

    2010-01-01

    This study presents results of ammonia nitrogen oxidation in absence of molecular oxygen. They were obtained after the operation of a sequential batch anaerobic reactor with fixed film. After the inoculation with sludge from an anaerobic stabilization pond of a slaughterhouse wastewater treatment plant, the reactor was fed with a synthetic culture media, as described by Martins (2007), in order to establish ideal conditions for growth and development of Anammox culture. The duration of the ba...

  3. Batch-reactor microfluidic device: first human use of a microfluidically produced PET radiotracer.

    Science.gov (United States)

    Lebedev, Artem; Miraghaie, Reza; Kotta, Kishore; Ball, Carroll E; Zhang, Jianzhong; Buchsbaum, Monte S; Kolb, Hartmuth C; Elizarov, Arkadij

    2013-01-01

    The very first microfluidic device used for the production of (18)F-labeled tracers for clinical research is reported along with the first human Positron Emission Tomography scan obtained with a microfluidically produced radiotracer. The system integrates all operations necessary for the transformation of [(18)F]fluoride in irradiated cyclotron target water to a dose of radiopharmaceutical suitable for use in clinical research. The key microfluidic technologies developed for the device are a fluoride concentration system and a microfluidic batch reactor assembly. Concentration of fluoride was achieved by means of absorption of the fluoride anion on a micro ion-exchange column (5 μL of resin) followed by release of the radioactivity with 45 μL of the release solution (95 ± 3% overall efficiency). The reactor assembly includes an injection-molded reactor chip and a transparent machined lid press-fitted together. The resulting 50 μL cavity has a unique shape designed to minimize losses of liquid during reactor filling and liquid evaporation. The cavity has 8 ports for gases and liquids, each equipped with a 2-way on-chip mechanical valve rated for pressure up to 20.68 bar (300 psi). The temperature is controlled by a thermoelectric heater capable of heating the reactor up to 180 °C from RT in 150 s. A camera captures live video of the processes in the reactor. HPLC-based purification and reformulation units are also integrated in the device. The system is based on "split-box architecture", with reagents loaded from outside of the radiation shielding. It can be installed either in a standard hot cell, or as a self-shielded unit. Along with a high level of integration and automation, split-box architecture allowed for multiple production runs without the user being exposed to radiation fields. The system was used to support clinical trials of [(18)F]fallypride, a neuroimaging radiopharmaceutical under IND Application #109,880. PMID:23135409

  4. 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.

  5. Development and characterization of the partial nitrification aerobic granules in a sequencing batch airlift reactor.

    Science.gov (United States)

    Song, Yanjun; Ishii, Satoshi; Rathnayake, Lashitha; Ito, Tsukasa; Satoh, Hisashi; Okabe, Satoshi

    2013-07-01

    In this study, partial nitrifying (PN) aerobic granules were developed in a sequencing batch airlift reactor by controlling the airflow rate and NH4(+) loading rate. The PN reactor produced an effluent with a NO2(-)/NH4(+) ratio of approximately one and with an NH4(+) conversion rate of 1.22 kg N m(-3)day(-1). More than 95% of the total organic carbon was removed during the process. On the basis of clone library analysis and fluorescence in situ hybridization, ammonia-oxidizing bacteria (AOB) closely related to Nitrosomonas eutropha and putative heterotrophic denitrifiers were mainly present near the surface of the PN aerobic granules. Microelectrode measurements revealed that both NH4(+) and NO2(-) were consumed near the surface (<200 μm), whereas no nitrate (NO3(-)) accumulation was observed throughout the granules. These results indicate that PN by AOB and nitrite denitrification by heterotrophs, but not nitrite oxidation, simultaneously occurred near the surface of the PN aerobic granules. PMID:23665689

  6. Effects of extracellular polymeric substances on granulation of anoxic sludge in sequencing batch reactor.

    Science.gov (United States)

    Wang, Binbin; Liu, Shunlian; Zhao, Hongmei; Zhang, Xinyan; Peng, Dangcong

    2012-01-01

    Variations of extracellular polymeric substances (EPS) and its components with sludge granulation were examined in a lab-scale sequencing batch reactor (SBR) which was fed with sodium nitrate and sodium acetate. Ultrasonication plus cation exchange resin (CER) were used as the EPS extraction method. Results showed that after approximately 90 d cultivation, the sludge in the reactor was almost granulated. The content of extracellular polysaccharides increased from 10.36 mg/g-VSS (volatile suspended solids) at start-up with flocculent sludge to 23.18 mg/g-VSS at 91 d with matured granular sludge, while the content of extracellular proteins were almost unchanged. Polysaccharides were the major components of EPS in anoxic granular sludge, accounting for about 70.6-79.0%, while proteins and DNA accounted for about 16.5-18.9% and 4.6-9.9%, respectively. It is proposed that EPS play a positive role in anoxic sludge granulation and polysaccharides might be strongly involved in aggregation of flocs into granules. PMID:22744684

  7. Dynamic Simulation of Batch Polymerization Reactor and Sensitivity Analysis of Styrene Homopolymerization

    Directory of Open Access Journals (Sweden)

    S. Kuzmić

    2015-03-01

    Full Text Available In this work, dynamic simulations of a batch reactor in the process of styrene homopolymerization in a xylene solution initiated with two types of peroxide initiators, monofunctional and bifunctional, was carried out. The monofunctional peroxide initiator has wide industrial applications, while the bifunctional initiator in preliminary studies has shown some advantages, such as the production of polymers with homogeneous structure along with achieving high or even complete conversion of monomers. Additionally, the reaction time can be significantly reduced with no modification of the reactor system. Computer simulation was performed using ChemCAD software for simulation of the chemical process and its integrated modules CC-Polymer developed exclusively for the analysis and design of radical and step polymerization processes. This software package based on the previously developed very complex kinetic models predicts the basic structural properties of polymers such as molar mass and its distribution (dispersity, which directly determines the quality and use of the final product. Dependencies of monomer conversion and structural characteristics of the polymers on the polymerization time obtained by computer simulation were compared with the experimental data. The satisfactory tendencies and a relatively good agreement were accomplished regarding the end of polymerization for most of the examined conditions. Additionally, a sensitivity study for homopolymeric system initiated with diperoxide initiator was performed. The effects of monomer concentration, initiator concentration, temperature and reaction time on the rate of polymerization (monomer conversion and the main structural properties of polymers were examined.

  8. Nitrification and aerobic denitrification in anoxic-aerobic sequencing batch reactor.

    Science.gov (United States)

    Alzate Marin, Juan C; Caravelli, Alejandro H; Zaritzky, Noemí E

    2016-01-01

    The aim of this study was to evaluate the feasibility of achieving nitrogen (N) removal using a lab-scale sequencing batch reactor (SBR) exposed to anoxic/aerobic (AN/OX) phases, focusing to achieve aerobic denitrification. This process will minimize emissions of N2O greenhouse gas. The effects of different operating parameters on the reactor performance were studied: cycle duration, AN/OX ratio, pH, dissolved oxygen concentration (DOC), and organic load. The highest inorganic N removal (NiR), close to 70%, was obtained at pH=7.5, low organic load (440mgCOD/(Lday)) and high aeration given by 12h cycle, AN/OX ratio=0.5:1.0 and DOC higher than 4.0mgO2/L. Nitrification followed by high-rate aerobic denitrification took place during the aerobic phase. Aerobic denitrification could be attributed to Tetrad-forming organisms (TFOs) with phenotype of glycogen accumulating organisms using polyhydroxyalkanoate and/or glycogen storage. The proposed AN/OX system constitutes an eco-friendly N removal process providing N2 as the end product. PMID:26512862

  9. Comparison of uranium(VI) removal by Shewanella oneidensis MR-1 in flow and batch reactors

    International Nuclear Information System (INIS)

    To better understand the interactions among metal contaminants, nutrients, and microorganisms in subsurface under fracture-flow conditions, iron-reducing biofilms (pure cultures of Shewanella oneidensis MR-1) were grown in six fracture flow reactors (FFRs) of different geometries. The spatial and temporal distribution of nutrients, contaminant, and bacteria were examined using a tracer dye (brilliant blue FCF) and microscopy. The results showed that plugging by bacterial cells depended on the geometry of the reactor; and iron-reducing biofilms grown in FFRs had a definite U(VI)-reduction capacity. To find out the U(VI)-reduction capacity of iron-reducing biofilms, batch experiments of U(VI) reduction were performed in repetitive addition mode. U(VI)-reduction rates of stationary phase grown iron-reducing cultures with and without spent medium decreased after each U(VI) addition. At the end of the fourth U(VI)-addition, stationary phase iron-reducing cultures treated with U(VI) with and without spent medium yielded grey and black precipitates, respectively. These grey and black U precipitates were analyzed using High Resolution-Transmission Electron Microscopy, Energy-dispersive X-ray spectroscopy, and X-ray diffraction. Data for randomly selected area of black and grey U precipitates showed that reduced U particles (3-6 nm) were crystalline and amorphous in nature, respectively. This information obtained in this study could be used to develop substrate addition strategies for metal immobilization in subsurface fracture flow systems

  10. The inoculum effect on the ammonia-oxidizing bacterial communities in parallel sequential batch reactors.

    Science.gov (United States)

    Wittebolle, Lieven; Verstraete, Willy; Boon, Nico

    2009-09-01

    Three identical sequential batch reactors (SBRs) were each inoculated with sludge from a full-scale wastewater treatment plant (WWTP) treating a waste stream of different origin, i.e. a hospital, a meat processing company, and a municipal WWTP. The SBRs were run in parallel for 84 consecutive days to investigate whether the reactors would become more phylogenetically similar or stay separated concerning their functionality and microbial communities. Overall, the nitrification functionality was high throughout the experiment, and the size and structure of the sludge flocs were very similar. The total bacterial and ammonia-oxidizing bacterial (AOB) communities were analyzed by PCR-DGGE. Cluster analysis demonstrated very distinct bacterial communities in the three SBRs, not showing any trend becoming more similar. The carrying capacity, dynamics and functional organization of the communities were assessed by DGGE analysis and based on these patterns the range-weighted richness, moving window analysis, and constructing Pareto-Lorenz evenness distribution curves were calculated. Between the SBRs, highly comparable internal structure and dynamics of the AOB communities were observed, although they had only one AOB DGGE band in common. These observations indicate that community characteristics such as the extent of biodiversity and dynamics are more important indicators of good microbial functionality than the presence of certain specific species. PMID:19596129

  11. Response of biodegradation characteristics of unacclimated activated sludge to moderate pressure in a batch reactor.

    Science.gov (United States)

    Xu, Rui-Xiao; Li, Bing; Zhang, Yong; Si, Ling; Zhang, Xian-Qiu; Xie, Biao

    2016-04-01

    This study was aimed to investigate the effect of moderate pressure on unacclimated activated sludge. Process of organic degradation, variation of carbon dioxide (CO2) concentration of off-gas and characteristics of extracellular polymeric substances (EPS) of activated sludge were analyzed using pressure-atmospheric comparative experiments in bench-scale batch reactors. It was found that moderate pressure increased the degradation rate more dramatically when the biological process ran under a higher organic load with much more oxygen demand, which illuminated that applications of the pressurized method to high concentration organic wastewaters would be more reasonable and practicable. High oxygen transfer impetus increased utilization of oxygen which not only promoted the biodegradation of organics in wastewater, but also led to more EPS consumption in activated sludge. CO2 concentration of off-gas was lower in the earlier stage due to CO2 being pressed into the liquid phase and converted into inorganic carbon (IC). More CO2 emission was observed during the pressurized aerobic process 160 min later. EPS in pressurized reactor was much lower, which may be an important way of sludge reduction by pressurized technology. PMID:26802261

  12. A batch reactor study to determine effectiveness factors of commercial HDS catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Marroquin, G.; Ancheyta, J.; Esteban, C. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, Mexico, D.F. 07730 (Mexico)

    2005-06-15

    In this work we present a series of experiments in order to determine effectiveness factor of commercial hydrodesulfurization (HDS) catalysts. All the tests were carried out with straight-run gas oil (SRGO) and CoMo/{gamma}-Al{sub 2}O{sub 3} catalyst in a batch reactor at 54kg/cm{sup 2} pressure, 320-380{sup o}C reaction temperature, 1000rpm stirring and reaction times between 1 and 6h. Four sizes of catalyst were employed for HDS experiments: (1) Commercial size, average particle size d{sub p}=2.5mm, (2) d{sub p}=0.833mm (20 mesh), (3) d{sub p}=0.369mm (40 mesh), and (4) d{sub p}=0.246mm (60 mesh). Before HDS tests all the samples were loaded to a continuous high-pressure reactor, then dried, soaked and sulfided with a mixture of SRGO and dimethyl disulfide (DMDS, 1wt.% sulfur) at typical activation conditions. The effects of reaction temperature, reaction time, and catalyst particle size on hydrodesulfurization are discussed and reaction order, kinetic constants, effectiveness factors and activation energies are calculated for each particle size. The values of effectiveness factors are within those reported in the literature.

  13. Comparison of four enhancement strategies for aerobic granulation in sequencing batch reactors

    International Nuclear Information System (INIS)

    Aerobic granules were developed in four identical sequencing batch reactors (SBRs) with synthetic wastewater to compare different strategies for the enhancement of granulation. The SBRs were operated by (a) increasing organic loading rate in R1; (b) reducing settling time in R2; (c) extending starvation period in R3; and (d) increasing shear force in R4. The results showed that four operational strategies were able to enhance aerobic granulation successfully in SBR, but that also showed different effect on the granulation process and characteristics of mature aerobic granules. The rapidest granulation was observed by using short settling time (R2) and the granules had higher extracellular polymeric substance (EPS) than other reactors. Extended starvation period (R3) and high shear force (R4) resulted in longer granulation period and the granules with higher integrity and smaller size. Higher organic loading rate (R1) resulted in the granules with larger size and higher K value. The maximum specific COD removal rates (qmax) of the granules in all SBRs were at a similar level (0.13-0.16 g COD/h-g VSS) but the granules in R1 and R2 had higher apparent half rate constant (K) of 18 and 16 mg/L, than those in R3 and R4 (2.8 and 3.3 mg/L).

  14. Microbial Aggregate and Functional Community Distribution in a Sequencing Batch Reactor with Anammox Granules

    KAUST Repository

    Sun, Shan

    2013-05-01

    Anammox (anaerobic ammonium oxidation) process is a one-step conversion of ammonia into nitrogen gas with nitrite as an electron acceptor. It has been developed as a sustainable technology for ammonia removal from wastewater in the last decade. For wastewater treatment, anammox biomass was widely developed as microbial aggregate where the conditions for enrichment of anammox community must be delicately controlled and growth of other bacteria especially NOB should be suppressed to enhance nitrogen removal efficiency. Little is known about the distribution of microbial aggregates in anammox process. Thus the objective of our study was to assess whether segregation of biomass occurs in granular anammox system. In this study, a laboratory-scale sequential batch reactor (SBR) was successfully operated for a period of 80 days with granular anammox biomass. Temporal and spatial distribution of microbial aggregates was studied by particle characterization system and the distribution of functional microbial communities was studied with qPCR and 16s rRNA amplicon pyrosequencing. Our study revealed the spatial and temporal distribution of biomass aggregates based on their sizes and density. Granules (>200 μm) preferentially accumulated in the bottom of the reactor while floccules (30-200 μm) were relatively rich at the top layer. The average density of aggregate was higher at the bottom than the density of those at the top layer. Degranulation caused by lack of hydrodynamic shear force in the top layer was considered responsible for this phenomenon. NOB was relatively rich in the top layer while percentage of anammox population was higher at the bottom, and anammox bacteria population gradually increased over a period of time. NOB growth was supposed to be associated with the increase of floccules based on the concurrent occurrence. Thus, segregation of biomass can be utilized to develop an effective strategy to enrich anammox and wash out NOB by shortening the settling

  15. Aerobic granules formation and nutrients removal characteristics in sequencing batch airlift reactor (SBAR) at low temperature

    International Nuclear Information System (INIS)

    To understand the effect of low temperature on the formation of aerobic granules and their nutrient removal characteristics, an aerobic granular sequencing batch airlift reactor (SBAR) has been operated at 10 deg. C using a mixed carbon source of glucose and sodium acetate. The results showed that aerobic granules were obtained and that the reactor performed in stable manner under the applied conditions. The granules had a compact structure and a clear out-surface. The average parameters of the granules were: diameter 3.4 mm, wet density 1.036 g mL-1, sludge volume index 37 mL g-1, and settling velocity 18.6-65.1 cm min-1. Nitrite accumulation was observed, with a nitrite accumulation rate (NO2--N/NOx--N) between 35% and 43% at the beginning of the start-up stage. During the stable stage, NOx was present at a level below the detection limit. However, when the influent COD concentration was halved (resulting in COD/N a reduction of the COD/N from 20:1 to 10:1) nitrite accumulation was observed once more with an effluent nitrite accumulation rate of 94.8%. Phosphorus release was observed in the static feeding phase and also during the initial 20-30 min of the aerobic phase. Neither the low temperature nor adjustment of the COD/P ratio from 100:1 to 25:1 had any influence on the phosphorus removal efficiency under the operating conditions. In the granular reactor with the influent load rates for COD, NH4+-N, and PO43--P of 1.2-2.4, 0.112 and 0.012-0.024 kg m-3 d-1, the respective removal efficiencies at low temperature were 90.6-95.4%, 72.8-82.1% and 95.8-97.9%.

  16. Reactor Safety Research Programs Quarterly Report January - March 1980

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, C. M

    1980-10-01

    This document summarizes the work performed by Pacific Northwest Laboratory from January 1 through March 31, 1980, for the Division of Reactor Safety Research within the Nuclear Regulatory Commission. Evaluation of nondestructive examination (NDE) techniques and instrumentation are reported; areas of investigation include demonstrating the feasibilty of determining structural graphite strength, evaluating the feasibilty of detecting and analyzing flaw growth in reactor pressure boundary systems, examining NDE reliability and probabilistic fracture mechanics, and assessing the remaining integrity of pressurized water reactor steam generator tubes where serviceinduced degradation has been indicated. Test assemblies and analytical support are being provided for experimental programs at other facilities. These programs include the loss-of-coolant accident simulation tests at the NRU reactor, Chalk River, Canada; the fuel rod deformation and post-accident coolability tests for the ESSOR Test Reactor Program, Ispra, Italy; the blowdown and reflood tests in the test facility at Cadarache, France; the instrumented fuel assembly irradiation program at Halden, Norway; and the experimental programs at the Power Burst Facility, Idaho National Engineering Laboratory. These programs will provide data for computer modeling of reactor system and fuel performance during various abnormal operating conditions.

  17. Reactor Safety Research Programs Quarterly Report October - December 1981

    Energy Technology Data Exchange (ETDEWEB)

    Edler, S. K.

    1982-03-01

    This document summarizes the work performed by Pacific Northwest laboratory (PNL) from October 1 through December 31, 1981, for the Division of Accident Evaluation, U.S. Nuclear Regulatory Commission (NRC). Evaluations of nondestructive examination (NDE) techniques and instrumentation are reported; areas of investigation include demonstrating the feasibility of determining the strength of structural graphite, evaluating the feasibility of detecting and analyzing flaw growth in reactor pressure boundary systems, examining NDE reliability and probabilistic fracture mechanics, and assessing the integrity of pressurized water reactor (PWR) steam generator tubes where serviceinduced degradation has been indicated. Experimental data and analytical models are being provided to aid in decision-making regarding pipe-to-pipe impacts following postulated breaks in high-energy fluid system piping. Core thermal models are being developed to provide better digital codes to compute the behavior of full-scale reactor systems under postulated accident conditions. Fuel assemblies and analytical support are being provided for experimental programs at other facilities. These programs include loss-of-coolant accident (LOCA) simulation tests at the NRU reactor, Chalk River, Canada; fuel rod deformation, severe fuel damage, and post accident coolability tests for the ESSOR reactor Super Sara Test Program, lspra, Italy; the instrumented fuel assembly irradiation program at Halden, Norway; and experimental programs at the Power Burst Facility, Idaho National Engineering Laboratory (INEL), Idaho Falls, Idaho. These programs will provide data for computer modeling of reactor system and fuel performance during various abnormal operating conditions.

  18. Biodegradation of high concentrations of phenol by baker’s yeast in anaerobic sequencing batch reactor

    Directory of Open Access Journals (Sweden)

    Ali Asghar Najafpoor

    2015-06-01

    Full Text Available Background: Phenol, as a pure substance, is used in many fields because of its disinfectant, germicidal, local anesthetic, and peptizing properties. Aqueous solutions of phenol are produced as waste in industries and discharged into the environment. Therefore, elevated concentrations of phenol may be found in air or water because of industrial discharge or the use of phenolic products. Method: The strains of Saccharomyces cerevisiae used in this project were natural strains previously purchased from Razavy company. They were grown at 30°C on Petri plates containing yeast extract glucose (YGC and then purified by being spread onto new plates, and isolated colonies were obtained. These colonies provided the basis of selection. Prepared strains were applied in anaerobic sequencing batch reactors (ASBRs as first seed. The experiment conditions were optimized using response surface methodology (RSM. After the determined runs were performed using Design-Expert software, data were analyzed using mentioned software as well. Results: This study evaluated the capability of baker’s yeast to remove phenol in high concentrations. The tested strains showed excellent tolerance to phenol toxicity at concentrations up to 6100 mg/L. Study of the batch degradation process showed that the phenol removal rate could exceed 99.9% in 24 hours at a concentration of 1000 mg/L. The results showed catechol is the first intermediate product of phenol degradation. In survey results of the Design–Expert software, R2 and Adeq precision were 0.97 and 25.65, respectively. Conclusion: The results demonstrated that ASBR performs robustly under variable influent concentrations of inhibitory compounds. The high removal performance despite the high phenol concentration may be a result of reactor operating strategies. Based on the progressive increase of inlet phenol concentration, allowing for an enhanced biomass acclimation in a short time, results at the microbiological levels

  19. Coexistence of nitrifying, anammox and denitrifying bacteria in a sequencing batch reactor

    Directory of Open Access Journals (Sweden)

    Michela eLangone

    2014-02-01

    Full Text Available Elevated nitrogen removal efficiencies from ammonium-rich wastewaters have been demonstrated by several applications, that combine nitritation and anammox processes. Denitrification will occur simultaneously when organic carbon is also present. In this study, the activity of aerobic ammonia oxidizing, anammox and denitrifying bacteria in a full scale Sequencing Batch Reactor, treating digester supernatants, was studied by means of batch-assays. AOB and anammox activities were maximum at pH of 8.0 and 7.8-8.0, rispectively. Short term effect of nitrite on anammox activity was studied, showing nitrite up to 42 mg/L did not result in inhibition. Both denitrification via nitrate and nitrite were measured. To reduce nitrite-oxidizing activity, high of NH3 – N (1.9-10 mg N-NH3/L and low nitrite (3-8 mg TNN/L are required conditions during the whole SBR cycle.Molecular analysis showed the nitritation-anammox sludge harbored a high microbial diversity, where each microorganism has a specific role. Using ammonia monooxygenase α –subunit (amoA gene as a marker, our analyses suggested different macro- and micro-environments in the reactor strongly affect the AOB community, allowing the development of different AOB species, such as N. europaea/eutropha and N. oligotropha groups, which improve the stability of nitritation process. A specific PCR primer set, used to target the 16S rRNA gene of anammox bacteria, confirmed the presence of the Ca. Brocadia fulgida type, able to grow in precence of organic matter and to tolerate high nitrite concentrations. The diversity of denitrifiers was assessed by using dissimilatory nitrite reductase (nirS gene-based analyses, who showed denitifiers were related to different betaproteobacterial genera, such as Thauera, Pseudomonas, Dechloromonas and Aromatoleum, able to assist in forming microbial aggregates. Concerning possible secondary processes, no n-damo bacteria were found while NOB from the genus of Nitrobacter

  20. 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

  1. Degradation of chlorpyrifos contaminated soil by bioslurry reactor operated in sequencing batch mode: bioprocess monitoring

    International Nuclear Information System (INIS)

    Bioslurry reactor (SS-SBR) was studied for the degradation of chlorpyrifos contaminated soil using native mixed microflora, by adopting sequencing batch mode (anoxic-aerobic-anoxic) operation. Reactor operation was monitored for a total cycle period of 72 h consisting of 3 h of FILL, 64 h REACT, 2 h of SETTLE, and 3 h of DECANT with chlorpyrifos concentrations of 3000 μg/g, 6000 μg/g and 12000 μg/g. At 3000 μg/g of chlorpyrifos concentration, 91% was degraded after 72 h of the cycle period, whereas in the case of 6000 μg/g of chlorpyrifos, 82.5% was degraded. However, for 12000 μg/g of chlorpyrifos, only 14.5% degradation was observed. The degradation rate was rapid at lower substrate concentration and 12000 μg/g of substrate concentration was found to be inhibitory. Chlorpyrifos removal rate was slow during the initial phase of the sequence operation. Half-life of chlorpyrifos degradation (t0.5) was estimated to be 6.3 h for 3000 μg/g of substrate, 17.5 h for 6000 μg/g and 732.2 h for 12000 μg/g. Process performance was assessed by monitoring chlorpyrifos concentration and biochemical process parameters viz., pH, oxidation and reduction potential (ORP), dissolved oxygen (DO), oxygen consumption rate (OCR) and microbial count (CFU) during sequence operation. From the experimental data obtained it can be concluded that the rate-limiting step with the bioslurry phase reactor in the process of chlorpyrifos degradation may be attributed to the concentration of substrate present in either soil or liquid phase. Periodic operations (SBR) by varying individual components of substrate with time in each process step place micro-organisms under nutritional changes from feast to famine and maintains a wide distribution in the population of micro-organisms resulting in high uptake of the substrate in the bioslurry reactor

  2. Preparation of Biodiesel from Microalgae and Palm Oil by Direct Transesterification in a Batch Microwave Reactor

    Science.gov (United States)

    Marwan; Suhendrayatna; Indarti, E.

    2015-06-01

    The present work was aimed to study the so-called direct transesterification of microalgae lipids to biodiesel in a batch microwave reactor. As a comparison, preparation of palm oil to biodiesel by alkaline catalyzed ethanolysis was also carried out. Palm oil biodiesel was recovered close to an equilibrium conversion (94-96% yield) under microwave heating for at least 6 min, while the conventional method required more than 45 minutes reaching the same yield. A very short reaction time suggests the benefit of microwave effect over conventional heating method in making biodiesel. FTIR analysis revealed the presence of fatty acid ethyl esters with no undesired chemical groups or compounds formed due to local heat generated by microwave effect, thus the conversion only followed transesterification route. Oil containing microalgae of Chlorella sp. isolated from the local brackish water pond was used as a potential source of biodiesel. High yield of biodiesel (above 0.6 g/g of dried algae) was also attainable for the direct transesterification of microalgae in the microwave reactor. Effect of water content of the algae biomass became insignificant at 11.9%(w/w) or less, related to the algae biomass dried for longer than 6 h. Fast transesterification of the algal oil towards equilibrium conversion was obtained at reaction time of 6 min, and at longer times the biodiesel yield remains unchanged. FAME profile indicates unsaturated fatty acids as major constituents. It was shown that microwave irradiation contributes not only to enhance the transeseterification, but also to assist effective release of fatty acid containing molecules (e.g. triacylglycerol, free fatty acids and phospholipids) from algal cells.

  3. Anaerobic co-digestion of food waste and landfill leachate in single-phase batch reactors

    International Nuclear Information System (INIS)

    Highlights: • Anaerobic co-digestion strategy for food waste treatment at OLR 41.8 g VS/L. • A certain amount of raw leachate effectively relieved acidic inhibition. • The study showed that food waste was completely degraded. - Abstract: In order to investigate the effect of raw leachate on anaerobic digestion of food waste, co-digestions of food waste with raw leachate were carried out. A series of single-phase batch mesophilic (35 ± 1 °C) anaerobic digestions were performed at a food waste concentration of 41.8 g VS/L. The results showed that inhibition of biogas production by volatile fatty acids (VFA) occurred without raw leachate addition. A certain amount of raw leachate in the reactors effectively relieved acidic inhibition caused by VFA accumulation, and the system maintained stable with methane yield of 369–466 mL/g VS. Total ammonia nitrogen introduced into the digestion systems with initial 2000–3000 mgNH4–N/L not only replenished nitrogen for bacterial growth, but also formed a buffer system with VFA to maintain a delicate biochemical balance between the acidogenic and methanogenic microorganisms. UV spectroscopy and fluorescence excitation–emission matrix spectroscopy data showed that food waste was completely degraded. We concluded that using raw leachate for supplement water addition and pH modifier on anaerobic digestion of food waste was effective. An appropriate fraction of leachate could stimulate methanogenic activity and enhance biogas production

  4. Effect of reaction temperature and time on neem methyl ester yield in a batch reactor

    International Nuclear Information System (INIS)

    Highlights: • Fatty acid profile and molecular mass of neem oil were determined. • Main effects of the factors and interaction were successfully quantified and compared. • Six (6) regression models were developed for methyl ester yield using NLREG software. • Results showed that the models can predict the methyl ester yield within 7% of experimental values. - Abstract: Experimental investigation of neem methyl ester yield in a batch reactor at different process conditions of temperature and reaction duration was carried out using a 2-factor, 5-level full factorial experimental design. Reaction temperature was varied between 40 °C and 60 °C, while reaction time was studied in the range of 30–120 min. The study, which was carried out using 1% w/w catalyst amount and alcohol to oil ratio of 6:1, showed that reaction temperature had a highly significant effect (p < 0.01) in comparison with reaction time, which had a significant effect (p < 0.05) on methyl ester yield. Six (6) empirical models were developed for the response variable of methyl ester yield using a non-linear regression analysis method, facilitated by NLREG version 6.3 software. Results showed that the mean predicted ester yield values and mean experimental values were not statistically different at the 95% confidence level, whereas the maximum deviation observed was 6.9%

  5. 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

  6. Ammonia and phenol removal in an internal-circulate sequencing batch airlift reactor.

    Science.gov (United States)

    Liu, Qifeng; Du, Cong; Yang, Ting; Fu, Zhimin

    2015-01-01

    An internal-circulate sequencing batch airlift reactor (IC-SBAR) has been developed to evaluate the efficiency of phenol and ammonia removal in treating synthetic wastewater. This study examined the effect of operation cycle on this system. Results showed that above 97.0% removal efficiencies of ammonia and phenol were achieved, which indicated that ammonia and phenol removals were not related to operation cycle. The average removal efficiency of 91.7% for chemical oxygen demand (COD) was achieved when the static/aerobic/settling time was 240 min/440 min/40 min. It was found that COD removal efficiency increased due to the time of operation cycle being prolonged. The average removal efficiencies of total inorganic nitrogen (TIN) were 65.8, 69.3 and 68.9% when average TIN concentrations were 78.0, 97.6 and 88.4 mg/L, respectively, in the influent. A cycle study showed that most phenol was degraded by aerobic microbes. Increasing the static time from 120 to 240 min resulted in the accumulation of NO2(-)-N, which indicated that the structures of the nitrifying bacterial community were changed. PMID:26114272

  7. Anaerobic co-digestion of food waste and landfill leachate in single-phase batch reactors.

    Science.gov (United States)

    Liao, Xiaofeng; Zhu, Shuangyan; Zhong, Delai; Zhu, Jingping; Liao, Li

    2014-11-01

    In order to investigate the effect of raw leachate on anaerobic digestion of food waste, co-digestions of food waste with raw leachate were carried out. A series of single-phase batch mesophilic (35±1°C) anaerobic digestions were performed at a food waste concentration of 41.8 g VS/L. The results showed that inhibition of biogas production by volatile fatty acids (VFA) occurred without raw leachate addition. A certain amount of raw leachate in the reactors effectively relieved acidic inhibition caused by VFA accumulation, and the system maintained stable with methane yield of 369-466 mL/g VS. Total ammonia nitrogen introduced into the digestion systems with initial 2000-3000 mgNH4-N/L not only replenished nitrogen for bacterial growth, but also formed a buffer system with VFA to maintain a delicate biochemical balance between the acidogenic and methanogenic microorganisms. UV spectroscopy and fluorescence excitation-emission matrix spectroscopy data showed that food waste was completely degraded. We concluded that using raw leachate for supplement water addition and pH modifier on anaerobic digestion of food waste was effective. An appropriate fraction of leachate could stimulate methanogenic activity and enhance biogas production. PMID:25062938

  8. Aerobic granulation strategy for bioaugmentation of a sequencing batch reactor (SBR) treating high strength pyridine wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaodong; Chen, Yan [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Zhang, Xin [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Suzhou Institute of Architectural Design Co., Ltd, Suzhou 215021, Jiangsu Province (China); Jiang, Xinbai; Wu, Shijing [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Shen, Jinyou, E-mail: shenjinyou@mail.njust.edu.cn [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Sun, Xiuyun; Li, Jiansheng; Lu, Lude [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Wang, Lianjun, E-mail: wanglj@mail.njust.edu.cn [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China)

    2015-09-15

    Abstract: Aerobic granules were successfully cultivated in a sequencing batch reactor (SBR), using a single bacterial strain Rhizobium sp. NJUST18 as the inoculum. NJUST18 presented as both a good pyridine degrader and an efficient autoaggregator. Stable granules with diameter of 0.5–1 mm, sludge volume index of 25.6 ± 3.6 mL g{sup −1} and settling velocity of 37.2 ± 2.7 m h{sup −1}, were formed in SBR following 120-day cultivation. These granules exhibited excellent pyridine degradation performance, with maximum volumetric degradation rate (V{sub max}) varied between 1164.5 mg L{sup −1} h{sup −1} and 1867.4 mg L{sup −1} h{sup −1}. High-throughput sequencing analysis exhibited a large shift in microbial community structure, since the SBR was operated under open condition. Paracoccus and Comamonas were found to be the most predominant species in the aerobic granule system after the system had stabilized. The initially inoculated Rhizobium sp. lost its dominance during aerobic granulation. However, the inoculation of Rhizobium sp. played a key role in the start-up process of this bioaugmentation system. This study demonstrated that, in addition to the hydraulic selection pressure during settling and effluent discharge, the selection of aggregating bacterial inocula is equally important for the formation of the aerobic granule.

  9. Reduction of excess sludge production in sequencing batch reactor through incorporation of chlorine dioxide oxidation

    International Nuclear Information System (INIS)

    In this study, chlorine dioxide (ClO2) instead of chlorine (Cl2) was proposed to minimize the formation of chlorine-based by-products and was incorporated into a sequencing batch reactor (SBR) for excess sludge reduction. The results showed that the sludge disintegrability of ClO2 was excellent. The waste activated sludge at an initial concentration of 15 g MLSS/L was rapidly reduced by 36% using ClO2 doses of 10 mg ClO2/g dry sludge which was much lower than that obtained using Cl2 based on similar sludge reduction efficiency. Maximum sludge disintegration was achieved at 10 mg ClO2/g dry sludge for 40 min. ClO2 oxidation can be successfully incorporated into a SBR for excess sludge reduction without significantly harming the bioreactor performance. The incorporation of ClO2 oxidation resulted in a 58% reduction in excess sludge production, and the quality of the effluent was not significantly affected.

  10. Posttreatment of effluent from coke-plant wastewater treatment system in sequencing batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Yu, H. [Nanyang Technological Univ., Singapore (Singapore). School of Civil and Structural Engineering; Gu, G.; Song, L. [Tongji Univ., Shanghai (China). School of Environmental Engineering

    1997-03-01

    The performance of sequencing batch reactors (SBRs) for the treatment of effluent from a conventional coke-plant wastewater biological treatment system has been evaluated. The results showed that an operating mode that incorporated two anoxic portions, one ahead of the aeration period and one after the aeration, was superior to the other modes (prearranged denitrification and postarranged denitrification) for nitrogen removal. The 4-h anoxic fill probably allowed some substrates in the influent to be stored in the biomass and led to subsequent storage-induced denitrification in the second anoxic portion during the reaction period. Under these conditions, the ammonia nitrogen (NH{sub 3}-N) and chemical oxygen demand (COD) reductions were 83.5 and 65.2%, respectively. During the fill period of an SBR, the organics concentration was reduced, probably due to the adsorption of organics onto activated sludge and dilution of the mixed liquor. Some readily biodegradable organics in the influent, such as phenol and o-cresol, were utilized by denitrifiers as a carbon source. A 16-h aeration significantly reduced the concentrations of o-cresol, 3,4-dimethyl phenol, and 2-quinoline alcohol, while reductions in quinoline, isoquinoline, indol, and methyl quinoline were limited.

  11. Treatment of textile effluent by chemical (Fenton's Reagent) and biological (sequencing batch reactor) oxidation

    International Nuclear Information System (INIS)

    The removal of organic compounds and colour from a synthetic effluent simulating a cotton dyeing wastewater was evaluated by using a combined process of Fenton's Reagent oxidation and biological degradation in a sequencing batch reactor (SBR). The experimental design methodology was first applied to the chemical oxidation process in order to determine the values of temperature, ferrous ion concentration and hydrogen peroxide concentration that maximize dissolved organic carbon (DOC) and colour removals and increase the effluent's biodegradability. Additional studies on the biological oxidation (SBR) of the raw and previously submitted to Fenton's oxidation effluent had been performed during 15 cycles (i.e., up to steady-state conditions), each one with the duration of 11.5 h; Fenton's oxidation was performed either in conditions that maximize the colour removal or the increase in the biodegradability. The obtained results allowed concluding that the combination of the two treatment processes provides much better removals of DOC, BOD5 and colour than the biological or chemical treatment alone. Moreover, the removal of organic matter in the integrated process is particularly effective when Fenton's pre-oxidation is carried out under conditions that promote the maximum increase in wastewater biodegradability.

  12. Aerobic granulation strategy for bioaugmentation of a sequencing batch reactor (SBR) treating high strength pyridine wastewater

    International Nuclear Information System (INIS)

    Abstract: Aerobic granules were successfully cultivated in a sequencing batch reactor (SBR), using a single bacterial strain Rhizobium sp. NJUST18 as the inoculum. NJUST18 presented as both a good pyridine degrader and an efficient autoaggregator. Stable granules with diameter of 0.5–1 mm, sludge volume index of 25.6 ± 3.6 mL g−1 and settling velocity of 37.2 ± 2.7 m h−1, were formed in SBR following 120-day cultivation. These granules exhibited excellent pyridine degradation performance, with maximum volumetric degradation rate (Vmax) varied between 1164.5 mg L−1 h−1 and 1867.4 mg L−1 h−1. High-throughput sequencing analysis exhibited a large shift in microbial community structure, since the SBR was operated under open condition. Paracoccus and Comamonas were found to be the most predominant species in the aerobic granule system after the system had stabilized. The initially inoculated Rhizobium sp. lost its dominance during aerobic granulation. However, the inoculation of Rhizobium sp. played a key role in the start-up process of this bioaugmentation system. This study demonstrated that, in addition to the hydraulic selection pressure during settling and effluent discharge, the selection of aggregating bacterial inocula is equally important for the formation of the aerobic granule

  13. High rate psychrophilic anaerobic digestion of high solids (35%) dairy manure in sequence batch reactor.

    Science.gov (United States)

    Saady, Noori M Cata; Massé, Daniel I

    2015-06-01

    Zero liquid discharge is increasingly adopted as an objective for waste treatment process. The objective of this study was to increase the feed total solids (TS) and the organic loading rate (OLR) fed to a novel psychrophilic (20°C) dry anaerobic digestion (PDAD). Duplicate laboratory-scale bioreactors were fed cow feces and wheat straw (35% TS in feed) at OLR of 6.0 g TCOD kg(-1) inoculum d(-1) during long-term operation (147 days consisting of 7 successive cycles). An overall average specific methane yield (SMY) of 151.8±7.9 N L CH4 kg(-1) VS fed with an averaged volatile solids removal of 42.4±4.3% were obtained at a volatile solids-based inoculum-to-substrate ratio (ISR) of 2.13±0.2. The operation was stable as indicated by biogas and VFAs profiles and the results were reproducible in successive cycles; a maximum SMY of 163.3±5.7 N L CH4 kg(-1) VS fed was obtained. Hydrolysis was the reaction limiting step. High rate PDAD of 35% TS dairy manure is possible in sequential batch reactor within 21 days treatment cycle length. PMID:25804501

  14. Cometabolic degradation of lincomycin in a Sequencing Batch Biofilm Reactor (SBBR) and its microbial community.

    Science.gov (United States)

    Li, Yancheng; Zhou, Jian; Gong, Benzhou; Wang, Yingmu; He, Qiang

    2016-08-01

    Cometabolism technology was employed to degrade lincomycin wastewater in Sequencing Batch Biofilm Reactor (SBBR). In contrast with the control group, the average removal rate of lincomycin increased by 56.0% and Total Organic Carbon (TOC) increased by 52.5% in the cometabolic system with glucose as growth substrate. Under the same condition, Oxidation-Reduction Potential (ORP) was 85.1±7.3mV in cometabolic system and 198.2±8.4mV in the control group, indicating that glucose changed the bulk ORP and created an appropriate growing environment for function bacteria. Functional groups of lincomycin were effectively degraded in cometabolic system proved by FTIR and GC-MS. Meanwhile, results of DGGE and 16S rDNA showed great difference in dominant populations between cometabolic system and the control group. In cometabolic system, Roseovarius (3.35%), Thiothrix (2.74%), Halomonas (2.49%), Ignavibacterium (2.02%), and TM7_genus_incertae_sedis (1.93%) were verified as dominant populations at genus level. Cometabolism may be synergistically caused by different functional dominant bacteria. PMID:27183234

  15. 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.

  16. Anaerobic co-digestion of food waste and landfill leachate in single-phase batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Xiaofeng; Zhu, Shuangyan; Zhong, Delai; Zhu, Jingping, E-mail: jpzhuhust@163.com; Liao, Li, E-mail: liaoli2003@126.com

    2014-11-15

    Highlights: • Anaerobic co-digestion strategy for food waste treatment at OLR 41.8 g VS/L. • A certain amount of raw leachate effectively relieved acidic inhibition. • The study showed that food waste was completely degraded. - Abstract: In order to investigate the effect of raw leachate on anaerobic digestion of food waste, co-digestions of food waste with raw leachate were carried out. A series of single-phase batch mesophilic (35 ± 1 °C) anaerobic digestions were performed at a food waste concentration of 41.8 g VS/L. The results showed that inhibition of biogas production by volatile fatty acids (VFA) occurred without raw leachate addition. A certain amount of raw leachate in the reactors effectively relieved acidic inhibition caused by VFA accumulation, and the system maintained stable with methane yield of 369–466 mL/g VS. Total ammonia nitrogen introduced into the digestion systems with initial 2000–3000 mgNH{sub 4}–N/L not only replenished nitrogen for bacterial growth, but also formed a buffer system with VFA to maintain a delicate biochemical balance between the acidogenic and methanogenic microorganisms. UV spectroscopy and fluorescence excitation–emission matrix spectroscopy data showed that food waste was completely degraded. We concluded that using raw leachate for supplement water addition and pH modifier on anaerobic digestion of food waste was effective. An appropriate fraction of leachate could stimulate methanogenic activity and enhance biogas production.

  17. 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.

  18. Feasibility study of sequencing batch reactor system for upgrading wastewater treatment in Malaysia.

    Science.gov (United States)

    Al-Shididi, S; Henze, M; Ujang, Z

    2003-01-01

    The objective of this study was to assess the feasibility of the Sequencing Batch Reactor (SBR) system for implementation in Malaysia. Theoretical, field, laboratory investigations, and modelling simulations have been carried out. The results of the study indicated that the SBR system was robust, relatively cost-effective, and efficient under Malaysian conditions. However, the SBR system requires highly skilled operators and continuous monitoring. This paper also attempted to identify operating conditions for the SBR system, which optimise both the removal efficiencies and the removal rates. The removal efficiencies could reach 90-96% for COD, up to 92% for TN, and 95% for SS. An approach to estimate a full operational cycle time, to estimate the de-sludging rate, and to control the biomass in the sludge has also been developed. About 4 hours react time was obtained, as 2.25 hours of nitrification with aerated slow fill and 1.75 hour of denitrification with HAc addition as an additional carbon source. Inefficient settling was one of the problems that affect the SBR effluent quality. The settling time was one hour for achieving Standard B (effluent quality) and 2 hours for Standard A. PMID:14753553

  19. Hydrolysis of Virgin Coconut Oil Using Immobilized Lipase in a Batch Reactor

    Directory of Open Access Journals (Sweden)

    Lee Suan Chua

    2012-01-01

    Full Text Available Hydrolysis of virgin coconut oil (VCO had been carried out by using an immobilised lipase from Mucor miehei (Lipozyme in a water-jacketed batch reactor. The kinetic of the hydrolysis was investigated by varying the parameters such as VCO concentration, enzyme loading, water content, and reaction temperature. It was found that VCO exhibited substrate inhibition at the concentration more than 40% (v/v. Lipozyme also achieved the highest production of free fatty acids, 4.56 mM at 1% (w/v of enzyme loading. The optimum water content for VCO hydrolysis was 7% (v/v. A relatively high content of water was required because water was one of the reactants in the hydrolysis. The progress curve and the temperature profile of the enzymatic hydrolysis also showed that Lipozyme could be used for free fatty acid production at the temperature up to 50°C. However, the highest initial reaction rate and the highest yield of free fatty acid production were at 45 and 40°C, respectively. A 100 hours of initial reaction time has to be compensated in order to obtain the highest yield of free fatty acid production at 40°C.

  20. Accelerating Aerobic Sludge Granulation by Adding Dry Sewage Sludge Micropowder in Sequencing Batch Reactors

    Science.gov (United States)

    Li, Jun; Liu, Jun; Wang, Danjun; Chen, Tao; Ma, Ting; Wang, Zhihong; Zhuo, Weilong

    2015-01-01

    Micropowder (20–250 µm) made from ground dry waste sludge from a municipal sewage treatment plant was added in a sequencing batch reactor (R2), which was fed by synthetic wastewater with acetate as carbon source. Compared with the traditional SBR (R1), aerobic sludge granulation time was shortened 15 days in R2. Furthermore, filamentous bacteria in bulking sludge were controlled to accelerate aerobic granulation and form large granules. Correspondingly, the SVI decreased from 225 mL/g to 37 mL/g. X-ray Fluorescence (XRF) analysis demonstrated that Al and Si from the micropowder were accumulated in granules. A mechanism hypotheses for the acceleration of aerobic granulation by adding dry sludge micropowder is proposed: added micropowder acts as nuclei to induce bacterial attachment; dissolved matters from the micropowder increase abruptly the organic load for starved sludge to control overgrown filamentous bacteria as a framework for aggregation; increased friction from the movement of micropowder forces the filaments which extend outwards to shrink for shaping granules. PMID:26308025

  1. 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.

  2. Influence of temperature on the characteristics of aerobic granulation in sequencing batch airlift reactors

    Institute of Scientific and Technical Information of China (English)

    SONG Zhiwei; REN Nanqi; ZHANG Kun; TONG Longyan

    2009-01-01

    Aerobic granular sludge were cultivated in sequencing batch airlift reactors (SBAR) at 25, 30 and 35℃,respectively. The effects of temperature on the granules characteristics were analyzed and the microbial community structures of the granules were probed using scanning electron micrograph (SEM) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that 30℃ is optimum for matured granules cultivated, where the granules had more compact structure, better settling ability and higher bioactivity, the OUR reached to 1.14 mg O2/(g MLVSS·min) with 97% removal rate of COD and 75% removal rate of TP, and the removal efficiency of NH3-N increased along with the temperature rising in the range of 68.5%-87.5%. DGGE profiles revealed that microbial community structure at 25℃ showed the lowest similarity with others, the sequencing results indicated that most of dominant microbes belonged to Actinobacteria and Proteobacterium. Thermomonas sp., Ottowia sp. and Curtobacterium ammoniigenes may act important roles respectively at different temperature.

  3. Effects of extracellular polymer substances on aerobic granulation in sequencing batch reactors

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-ping; LIU Li-li; YAO Jie; SUN Li-xin; CAI Wei-min

    2009-01-01

    The effects of extracellular polymeric substances (EPS) on aerobic granulation in sequencing batch reactors (SBR) were investigated by evaluating the EPS content, and the relationship between EPS composition and surface properties of glucose-fed aerobic granules. The results show that aerobic granular sludge contains more EPS than seed sludge, and it is about 47 mg/gMLSS. Corresponding to the changes of EPS, the surface charge of microorganisms in granules increases from -0. 732 to -0. 845 meq/gMLSS, whereas the hydrophobicry changes significantly from 48.46% to 73. 16%. It is obviously that changes of EPS in sludge alter the negative surface charge and hydrophobieity of microorganisms in granules, enhance the polymeric interaction and promote the aerobic granulation. Moreover, EPS can serve as carbon and energy reserves in granulation, thus the growth between the interior and exterior bacteria is balanced, and the integrality of granules is maintained.SEM observation of the granules exhibits that EPS in granules are ropy ; by mixing with bacteria, compact matrix structure can be formed. The distribution of EPS in granules profiles the importance of EPS storage. It can be concluded that EPS play a crucial role in aerobic granulation.

  4. Conventional and dynamic safety analysis: Comparison on a chemical batch reactor

    International Nuclear Information System (INIS)

    Dynamic safety analysis methodologies are an attractive approach to tackle systems with complex dynamics (i.e. with behavior highly dependent on the values of the process parameters): this is often the case in various areas of the chemical industry. The present paper compares analyses with Probabilistic Safety Assessment (PSA)/Quantitative Risk Assessment (QRA) methods with those from a dynamic methodology (Monte Carlo simulation). The results of a case study for a chemical batch reactor from the literature, overall risk figure and main contributors, are examined. The comparison has shown that, provided that the event success criteria are appropriately defined, consistent results can be obtained; otherwise important accident scenarios, identifiable by the dynamic Monte Carlo simulation, are possibly missed in the application of conventional methods. Defining such criteria was quite resource-intensive: for the analysis of this small system, the success criteria definitions required many system simulation runs (about 1000). Such large numbers of runs may not be practical in industrial-scale applications. It is shown that success criteria obtained with fewer simulation runs could have led to different quantitative PSA results and to the omission of important accident scenario variants.

  5. Photodegradation of bisphenol-A in a batch TiO2 suspension reactor

    International Nuclear Information System (INIS)

    In this work, the photocatalytic behaviors of bisphenol-A (BPA), which has been listed as one of endocrine disrupting chemicals, were carried out in a batch TiO2 suspension reactor. The photodegradation efficiency has been investigated under the controlled process parameters including initial BPA concentration (i.e., 1-50 mg L-1), TiO2 dosage (i.e., 5-600 mg/200 cm3), initial pH (i.e., 3-11), and temperature (i.e., 10-70 deg. C). It was found that the optimal conditions in the photoreaction process could be coped with at initial BPA concentration = 20 mg L-1, TiO2 dosage = 0.5 g L-1 (100 mg/200 cm3), initial pH = 7.0, and temperature = 25 deg. C. According to the Langmuir-Hinshelwood model, the results showed that the photodegradation kinetics for the destruction of BPA in water also followed the first-order model well. The apparent first-order reaction constants (kobs), thus obtained from the fittings of the model, were in line with the destruction-removal efficiencies of BPA in all the photocatalytic experiments. Based on the intermediate products identified in the study, the possible mechanisms for the photodegradation of BPA in water were also proposed in the present study.

  6. Aerobic granules formation and nutrients removal characteristics in sequencing batch airlift reactor (SBAR) at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Bao Ruiling [State Key Laboratory of Urban Water Resource and Environment, Harbin University of Technology, Harbin 150090 (China); Yu Shuili, E-mail: ysl@vip.163.com [State Key Laboratory of Urban Water Resource and Environment, Harbin University of Technology, Harbin 150090 (China) and State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092 (China); Shi Wenxin; Zhang Xuedong; Wang Yulan [State Key Laboratory of Urban Water Resource and Environment, Harbin University of Technology, Harbin 150090 (China)

    2009-09-15

    To understand the effect of low temperature on the formation of aerobic granules and their nutrient removal characteristics, an aerobic granular sequencing batch airlift reactor (SBAR) has been operated at 10 deg. C using a mixed carbon source of glucose and sodium acetate. The results showed that aerobic granules were obtained and that the reactor performed in stable manner under the applied conditions. The granules had a compact structure and a clear out-surface. The average parameters of the granules were: diameter 3.4 mm, wet density 1.036 g mL{sup -1}, sludge volume index 37 mL g{sup -1}, and settling velocity 18.6-65.1 cm min{sup -1}. Nitrite accumulation was observed, with a nitrite accumulation rate (NO{sub 2}{sup -}-N/NO{sub x}{sup -}-N) between 35% and 43% at the beginning of the start-up stage. During the stable stage, NO{sub x} was present at a level below the detection limit. However, when the influent COD concentration was halved (resulting in COD/N a reduction of the COD/N from 20:1 to 10:1) nitrite accumulation was observed once more with an effluent nitrite accumulation rate of 94.8%. Phosphorus release was observed in the static feeding phase and also during the initial 20-30 min of the aerobic phase. Neither the low temperature nor adjustment of the COD/P ratio from 100:1 to 25:1 had any influence on the phosphorus removal efficiency under the operating conditions. In the granular reactor with the influent load rates for COD, NH{sub 4}{sup +}-N, and PO{sub 4}{sup 3-}-P of 1.2-2.4, 0.112 and 0.012-0.024 kg m{sup -3} d{sup -1}, the respective removal efficiencies at low temperature were 90.6-95.4%, 72.8-82.1% and 95.8-97.9%.

  7. Simulation of kefiran production of Lactobacillus kefiranofaciens JCM6985 in fed-batch reactor

    OpenAIRE

    Benjamas Cheirsilp

    2006-01-01

    Kinetics of kefiran production by Lactobacillus kefiranofaciens JCM6985 has been investigated. A mathematical model taking into account the mechanism of exopolysaccharides production has been developed. Experiments were carried out in batch mode in order to obtain kinetic model parameters that were further applied to simulate fed-batch processes. A simplification of parameter fitting was also introduced for complicated model. The fed-batch mode allows more flexibility in the control of the su...

  8. Durability and reutilization capabilities of a Ni-Ru catalyst for the hydrolysis of sodium borohydride in batch reactors

    OpenAIRE

    Pinto, A.M.F.R.; M.J.F. Ferreira; Fernandes, V. R.; Rangel, C. M.

    2011-01-01

    The study of catalyst durability and reutilization on catalyzed hydrolysis of sodium borohydride is essential from an application point of view. Few works on this topic are available in the literature. In the present work, a powder nickel-ruthenium based catalyst, unsupported, used in two different schemes of NaBH 4 hydrolysis (alkaline and alkali free hydrolysis), performed in batch reactors with different volumes and bottom geometries (flat and conical), was investigated in terms of durabil...

  9. COMBINING A SEQUENCING BATCH REACTOR WITH HETEROGENEOUS PHOTOCATALYSIS (TiO2/UV) FOR TREATING A PENCIL MANUFACTURER'S WASTEWATER

    OpenAIRE

    R. N. Padovan; E. B. Azevedo

    2015-01-01

    Abstract A Sequencing Batch Reactor (SBR) was combined with heterogeneous photocatalysis (TiO2/UV) as a tertiary treatment for a pencil manufacturer's wastewater. The SBR removed almost all Chemical Oxygen Demand (COD) from the wastewater, although color was barely removed. Photocatalysis was optimized using a factorial design. Final COD, Dissolved Organic Carbon (DOC), and color removals were 95%, 80%, and 93%, respectively. Treated wastewater showed no ecotoxicity towards Lactuca sativa. Co...

  10. Evaluation of Critical Operating Conditions for a Semi-batch Reactor by Complementary Use of Sensitivity and Divergence Criteria

    OpenAIRE

    De Maria, G.; Stefan, D.-N.

    2011-01-01

    This paper presents a comparison of several effective methods of deriving the critical feeding conditions for the case of a semi-batch catalytic reactor used for the acetoacetylation of pyrrole with diketene in homogeneous liquid phase. The reaction is known to be of high risk due to the very exothermic (polymerisation) side-reactions involving reactive diketene. In order to perform the sensitivity analysis, both the Morbidelli-Varma sensitivity criterion and div-methods were used, the latter...

  11. Feasibility of a pulsed sequencing batch reactor with anaerobic aggregated biomass for the treatment of low strenght wastewaters

    OpenAIRE

    Brito, A. G.; Rodrigues, A.C.; Melo, L. F.

    1997-01-01

    This study concerns an assessment of a SBR operation that associates anaerobic aggregated biomass with a pulsed action during the reaction phase, a system named Pulsed Sequencing Batch Reactor (P-SBR). The system uses a diaphragm pump as a pulsator unit to increase the liquid-solid contact, in order to avoid dead zones and possible external mass transfer resistance. A preliminary study of the operation of the reactor was performed with a low strenght synthetic wastewater with a COD near 1000m...

  12. 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

  13. Application of Forward Osmosis Membrane in a Sequential Batch Reactor for Water Reuse

    KAUST Repository

    Li, Qingyu

    2011-07-01

    Forward osmosis (FO) is a novel membrane process that potentially can be used as an energy-saving alternative to conventional membrane processes. The objective of this study is to investigate the performance of a FO membrane to draw water from wastewater using seawater as draw solution. A study on a novel osmotic sequential batch reactor (OsSBR) was explored. In this system, a plate and frame FO cell including two flat-sheet FO membranes was submerged in a bioreactor treating the wastewater. We found it feasible to treat the wastewater by the OsSBR process. The DOC removal rate was 98.55%. Total nitrogen removal was 62.4% with nitrate, nitrite and ammonium removals of 58.4%, 96.2% and 88.4% respectively. Phosphate removal was almost 100%. In this OsSBR system, the 15-hour average flux for a virgin membrane with air scouring is 3.103 LMH. After operation of 3 months, the average flux of a fouled membrane is 2.390 LMH with air scouring (23% flux decline). Air scouring can help to remove the loose foulants on the active layer, thus helping to maintain the flux. Cleaning of the FO membrane fouled in the active layer was probably not effective under the conditions of immersing the membrane in the bioreactor. LC-OCD results show that the FO membrane has a very good performance in rejecting biopolymers, humics and building blocks, but a limited ability in rejecting low molecular weight neutrals.

  14. 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.

  15. Methane coupling by membrane reactor. Quarterly technical progress report, September 25, 1995--December 24, 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-15

    The performance of the third type of catalytic membrane reactor configuration, with catalyst deposited in the membrane and no catalyst or inert materials in the tube side, was evaluated. The C{sub 2} selectivity obtained was about 10% due to the gas phase reaction in the empty tube side of the reactor. The membrane reactor with an oxygen-permeable dense membrane has been built. The use of a dense membrane will eliminate the loss of hydrocarbon from the tube side to the shell side, as observed in the Vycor glass membrane reactor. Also, air can be used as the oxygen source without contaminating the product. La/MgO was synthesized and will be used as the catalyst for the dense membrane reactor. This catalyst was reported in the literature to show significant improvement of C{sub 2} selectivity and yield for oxidative coupling of methane in a packed-bed reactor by using the operation mode of staged-feed of oxygen. A reactor mode for methane oxidative coupling in reactors with both distributed oxygen feed and C{sub 2} product removal was developed based on the general model of cross-flow reactors reported in the last quarterly report. A distributed oxygen feed could give rise to much higher C{sub 2} yield than the co-feed reactor as long as the space time is long enough. In the case of a two-membrane reactor, where oxygen is supplied by one membrane and products are removed through the other membrane, a high separation factor of C{sub 2} product to methane for the product-removal membrane is critical to achieve high C{sub 2} yield.

  16. Diversity and dynamics of dominant and rare bacterial taxa in replicate sequencing batch reactors operated under different solids retention time

    KAUST Repository

    Bagchi, Samik

    2014-10-19

    In this study, 16S rRNA gene pyrosequencing was applied in order to provide a better insight on the diversity and dynamics of total, dominant, and rare bacterial taxa in replicate lab-scale sequencing batch reactors (SBRs) operated at different solids retention time (SRT). Rank-abundance curves showed few dominant operational taxonomic units (OTUs) and a long tail of rare OTUs in all reactors. Results revealed that there was no detectable effect of SRT (2 vs. 10 days) on Shannon diversity index and OTU richness of both dominant and rare taxa. Nonmetric multidimensional scaling analysis showed that the total, dominant, and rare bacterial taxa were highly dynamic during the entire period of stable reactor performance. Also, the rare taxa were more dynamic than the dominant taxa despite expected low invasion rates because of the use of sterile synthetic media.

  17. Anaerobic ammonium oxidation by Nitrosomonas spp. and anammox bacteria in a sequencing batch reactor.

    Science.gov (United States)

    Lek Noophan, Pongsak; Sripiboon, Siriporn; Damrongsri, Mongkol; Munakata-Marr, Junko

    2009-02-01

    A sequencing batch reactor (SBR) was inoculated with mixed nitrifying bacteria from an anoxic tank at the conventional activated sludge wastewater treatment plant in Nongkhaem, Bangkok, Thailand. This enriched nitrifying culture was maintained under anaerobic conditions using ammonium (NH(4)(+)) as an electron donor and nitrite (NO(2)(-)) as an electron acceptor. Autotrophic ammonium oxidizing bacteria survived under these conditions. The enrichment period for anammox culture was over 100 days. Both ammonium and nitrite conversion rates were proportional to the biomass of ammonium oxidizing bacteria; rates were 0.08 g N/gV SS/d and 0.05 g N/g VSS/d for ammonium and nitrite, respectively, in a culture maintained for 3 months at 42 mg N/L ammonium. The nitrogen transformation rate at a ratio of NH(4)(+)-N to NO(2)(-)-N of 1:1.38 was faster, and effluent nitrogen levels were lower, than at ratios of 1:0.671, 1:2.18, and 1:3.05. Fluorescent in situ hybridization (FISH) was used to identify specific autotrophic ammonium oxidizing bacteria (Nitrosomonas spp., Candidatus Brocadia anammoxidans, and Candidatus Kuenenia stuttgartiensis). The ammonium oxidizing culture maintained at 42 mg N/L ammonium was enriched for Nitrosomonas spp. (30%) over Candidati B. anammoxidans and K. stuttgartiensis (2.1%) while the culture maintained at 210 mg N/L ammonium was dominated by Candidati B. anammoxidans and K. stuttgartiensis (85.6%). The specific nitrogen removal rate of anammox bacteria (0.6 g N/g anammox VSS/d) was significantly higher than that of ammonium oxidizing bacteria (0.4 g N/g Nitrosomonas VSS/d). Anammox bacteria removed up to 979 mg N/L/d of total nitrogen (ammonium:nitrite concentrations, 397:582 mg N/L). These results suggest significant promise of this approach for application to wastewater with high nitrogen but low carbon content, such as that found in Bangkok. PMID:18423965

  18. A study on the use of the BioBall® as a biofilm carrier in a sequencing batch reactor.

    Science.gov (United States)

    Masłoń, Adam; Tomaszek, Janusz A

    2015-11-01

    Described in this study are experiments conducted to evaluate the removal of organics and nutrients from synthetic wastewater by a moving bed sequencing batch biofilm reactor using BioBall® carriers as biofilm media. The work involving a 15L-laboratory scale MBSBBR (moving bed sequencing batch biofilm reactor) model showed that the wastewater treatment system was based on biochemical processes taking place with activated sludge and biofilm microorganisms developing on the surface of the BioBall® carriers. Classical nitrification and denitrification and the typical enhanced biological phosphorus removal process were achieved in the reactor analyzed, which operated with a volumetric organic loading of 0.84-0.978gCODL(-1)d(-1). The average removal efficiencies for COD, total nitrogen and total phosphorus were found to be 97.7±0.5%, 87.8±2.6% and 94.3±1.3%, respectively. Nitrification efficiency reached levels in the range 96.5-99.7%. PMID:26298401

  19. Biological Treatment of Edible Oil Refinery Wastewater using Activated Sludge Process and Sequencing Batch Reactors - A Review

    Directory of Open Access Journals (Sweden)

    Devendra Dohare

    2014-12-01

    Full Text Available This review paper intends to provide an overall vision of ASP and SBR technology as an alternative method for biological treatment of edible oil refinery wastewater. Edible oil refinery effluent is considered the most harmful waste for the environment if discharged untreated. Edible oil effluent is a yellowish liquid that contains high Dissolved Solids, Oil and Grease, high COD and BOD values, low pH, Total Kjeldahl Nitrogen, Ammonia Nitrogen, and Total Phosphorus. The activated sludge process is used to treat waste stream that are high in organic loading and biodegradable compounds. It is most widely used biological process for the treatment of edible oil refinery wastewater. Sequencing batch reactor is a modification of activated sludge process which has been successfully used to treat edible oil refinery wastewater. The same can be successfully treated by sequencing batch reactor process.The advantages of SBR technology are single-tank configuration, easily expandable, flexibility in operation, feasibility of operation at low retention time, control over microbial population and various reactor configuration. Their studies resulted in very high percentage removal of BOD, COD, Total Dissolved Solids and Suspended Solids respectively. The review discusses some of the published works in addition to experiences of the authors.

  20. pH-oscillations in the bromate–sulfite reaction in semibatch and in gel-fed batch reactors

    International Nuclear Information System (INIS)

    The simplest bromate oxidation based pH-oscillator, the two component BrO3−–SO32– flow system was transformed to operate under semibatch and closed arrangements. The experimental preconditions of the pH-oscillations in semibatch configuration were predicted by model calculations. Using this information as guideline large amplitude (ΔpH∼3), long lasting (11–24 h) pH-oscillations accompanied with only a 20% increase of the volume in the reactor were measured when a mixture of Na2SO3 and H2SO4 was pumped into the solution of BrO3− with a very low rate. Batch-like pH-oscillations, similar in amplitude and period time appeared when the sulfite supply was substituted by its dissolution from a gel layer prepared previously in the reactor in presence of high concentration of Na2SO3. The dissolution vs time curve and the pH-oscillations in the semibatch and closed systems were successfully simulated. Due to the simplicity in composition and in experimental technique, the semibatch and batch-like BrO3−–SO32– pH-oscillators may become superior to their CSTR (continuous flow stirred tank reactor) version in some present and future applications

  1. pH-oscillations in the bromate-sulfite reaction in semibatch and in gel-fed batch reactors

    Science.gov (United States)

    Poros, Eszter; Kurin-Csörgei, Krisztina; Szalai, István; Rábai, Gyula; Orbán, Miklós

    2015-06-01

    The simplest bromate oxidation based pH-oscillator, the two component BrO3--SO32- flow system was transformed to operate under semibatch and closed arrangements. The experimental preconditions of the pH-oscillations in semibatch configuration were predicted by model calculations. Using this information as guideline large amplitude (ΔpH˜3), long lasting (11-24 h) pH-oscillations accompanied with only a 20% increase of the volume in the reactor were measured when a mixture of Na2SO3 and H2SO4 was pumped into the solution of BrO3- with a very low rate. Batch-like pH-oscillations, similar in amplitude and period time appeared when the sulfite supply was substituted by its dissolution from a gel layer prepared previously in the reactor in presence of high concentration of Na2SO3. The dissolution vs time curve and the pH-oscillations in the semibatch and closed systems were successfully simulated. Due to the simplicity in composition and in experimental technique, the semibatch and batch-like BrO3--SO32- pH-oscillators may become superior to their CSTR (continuous flow stirred tank reactor) version in some present and future applications.

  2. Removal of fluoxetine and its effects in the performance of an aerobic granular sludge sequential batch reactor

    International Nuclear Information System (INIS)

    Highlights: • Enantioselective removal of fluoxetine by aerobic granular sludge was evaluated. • Sorption of fluoxetine to aerobic granules occurred. • Bacterial community gradually changed during operation of sequential batch reactor. • Main biological processes occurring within the granules were preserved. • Overall performance of the reactor was recovered after initial fluoxetine shock loads. - Abstract: Fluoxetine (FLX) is a chiral fluorinated pharmaceutical mainly indicated for treatment of depression and is one of the most distributed drugs. There is a clear evidence of environmental contamination with this drug. Aerobic granular sludge sequencing batch reactors constitute a promising technology for wastewater treatment; however the removal of carbon and nutrients can be affected by micropollutants. In this study, the fate and effect of FLX on reactor performance and on microbial population were investigated. FLX adsorption/desorption to the aerobic granules was observed. FLX shock loads (≤4 μM) did not show a significant effect on the COD removal. Ammonium removal efficiency decreased in the beginning of first shock load, but after 20 days, ammonia oxidizing bacteria became adapted. The nitrite concentration in the effluent was practically null indicating that nitrite oxidizing bacteria was not inhibited, whereas, nitrate was accumulated in the effluent, indicating that denitrification was affected. Phosphate removal was affected at the beginning showing a gradual adaptation, and the effluent concentration was <0.04 mM after 70 days. A shift in microbial community occurred probably due to FLX exposure, which induced adaptation/restructuration of the microbial population. This contributed to the robustness of the reactor, which was able to adapt to the FLX load

  3. Removal of fluoxetine and its effects in the performance of an aerobic granular sludge sequential batch reactor

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Irina S.; Amorim, Catarina L. [CBQF – Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto (Portugal); Ribeiro, Ana R. [CBQF – Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto (Portugal); Centro de Química Medicinal da Universidade do Porto (CEQUIMED-UP), Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto (Portugal); CESPU, Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Rua Central de Gandra 1317, 4585-116 Gandra PRD (Portugal); Mesquita, Raquel B.R. [CBQF – Centro de Biotecnologia e Química Fina – Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto (Portugal); Laboratory of Hydrobiology, Institute of Biomedical Sciences Abel Salazar (ICBAS) and Institute of Marine Research (CIIMAR), Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto (Portugal); and others

    2015-04-28

    Highlights: • Enantioselective removal of fluoxetine by aerobic granular sludge was evaluated. • Sorption of fluoxetine to aerobic granules occurred. • Bacterial community gradually changed during operation of sequential batch reactor. • Main biological processes occurring within the granules were preserved. • Overall performance of the reactor was recovered after initial fluoxetine shock loads. - Abstract: Fluoxetine (FLX) is a chiral fluorinated pharmaceutical mainly indicated for treatment of depression and is one of the most distributed drugs. There is a clear evidence of environmental contamination with this drug. Aerobic granular sludge sequencing batch reactors constitute a promising technology for wastewater treatment; however the removal of carbon and nutrients can be affected by micropollutants. In this study, the fate and effect of FLX on reactor performance and on microbial population were investigated. FLX adsorption/desorption to the aerobic granules was observed. FLX shock loads (≤4 μM) did not show a significant effect on the COD removal. Ammonium removal efficiency decreased in the beginning of first shock load, but after 20 days, ammonia oxidizing bacteria became adapted. The nitrite concentration in the effluent was practically null indicating that nitrite oxidizing bacteria was not inhibited, whereas, nitrate was accumulated in the effluent, indicating that denitrification was affected. Phosphate removal was affected at the beginning showing a gradual adaptation, and the effluent concentration was <0.04 mM after 70 days. A shift in microbial community occurred probably due to FLX exposure, which induced adaptation/restructuration of the microbial population. This contributed to the robustness of the reactor, which was able to adapt to the FLX load.

  4. Performance of Co-Mo/Al2O3 Nano Catalyst for CAMERE Process in a Batch Reactor

    OpenAIRE

    Gharibi Kharaji, A.; Shariati, A.

    2013-01-01

    Reverse Water Gas Shift (RWGS) reaction is one of the main reactions that can be used to reduce greenhouse gas emissions. Through this reaction CO2 is converted to CO to produce beneficial chemicals such as methanol. In the present study, Mo/Al2O3 and Co-Mo/Al2O3 catalysts were synthesised using impregnation method. The structures of the catalysts were studied using XRD, XRF and TEM techniques. Activity and selectivity of both catalysts were investigated in a batch reactor and the results ...

  5. Validation of the tanks-in series with recycle model for mixing characterization in anchor-agitated batch reactors

    International Nuclear Information System (INIS)

    Presently work settles down the fitness of the tanks-in-series with recycle model for describing the blending in a 100 liters anchor-agitated batch reactor. This model is used to establish the relationship between the mixing-rate number and the Reynolds number The basic information needed was obtained from the curves that record the counting rate variations of the 99mTc with time, during the mixing process. The mixing-rate number shows a tendency to a constant value of 7,8 within the Reynolds range between 4,78x104 and 2,68x105

  6. Effects of the addition of an organic polymer on the hydrolysis of sodium tetrahydroborate in batch reactors

    OpenAIRE

    M. J. F. Ferreira; Fernandes, V. R.; Gales, L.; Rangel, C. M.; Pinto, A. M. F. R.

    2010-01-01

    An experimental study is presented both on the generation and storage of molecular hydrogen (H2) by small additions of an organic polymer - carboxymethyl cellulose (CMC) - to sodium borohydride (NaBH4) through the alkaline hydrolysis, in the presence of a powdered nickel-ruthenium based catalyst reused from 274 to 282 times. The experiments were performed at 45 °C in two batch reactors with internal volumes of 0.229 L and 0.369 L, made of stainless-steel with bottom conical shape, positioned ...

  7. COMBINING A SEQUENCING BATCH REACTOR WITH HETEROGENEOUS PHOTOCATALYSIS (TiO2/UV FOR TREATING A PENCIL MANUFACTURER'S WASTEWATER

    Directory of Open Access Journals (Sweden)

    R. N. Padovan

    2015-03-01

    Full Text Available Abstract A Sequencing Batch Reactor (SBR was combined with heterogeneous photocatalysis (TiO2/UV as a tertiary treatment for a pencil manufacturer's wastewater. The SBR removed almost all Chemical Oxygen Demand (COD from the wastewater, although color was barely removed. Photocatalysis was optimized using a factorial design. Final COD, Dissolved Organic Carbon (DOC, and color removals were 95%, 80%, and 93%, respectively. Treated wastewater showed no ecotoxicity towards Lactuca sativa. Color removal kinetics (photocatalysis followed a pseudo-first order model. The SBR + AOP (Advanced Oxidation Process, TiO2/UV combination was a feasibility choice for removing both COD and color from this wastewater.

  8. Structure Analysis of Aerobic Granule from a Sequencing Batch Reactor for Organic Matter and Ammonia Nitrogen Removal

    OpenAIRE

    Jun Li; Ang Cai; Danjun Wang; Chao Chen; Yongjiong Ni

    2014-01-01

    Aerobic granules were cultivated in a sequencing batch reactor (SBR). COD and ammonia nitrogen removal rate were 94% and 99%, respectively. The diameter, settling velocity and SVI10 of granules ranged from 2 to 5 mm, 80 to 110 m/h and about 40 mL/g, respectively. Freezing microtome images, DO concentration profiles by microelectrode, distribution of bacteria and EPS by confocal laser scanning microscopy (CLSM) show that the aerobic granules have a three-layer structure. Each layer has diffe...

  9. Fermentative hydrogen production from liquid swine manure with glucose supplement using an anaerobic sequencing batch reactor

    Science.gov (United States)

    Wu, Xiao

    2009-12-01

    The idea of coupling renewable energy production and agricultural waste management inspired this thesis. The production of an important future fuel---hydrogen gas---from high strength waste stream-liquid swine manure---using anaerobic treatment processes makes the most sustainable sense for both wastewater utilization and energy generation. The objectives of this thesis were to develop a fermentation process for converting liquid swine manure to hydrogen and to maximize hydrogen productivity. Anaerobic sequencing batch reactor (ASBR) systems were constructed to carry out this fermentation process, and seed sludge obtained from a dairy manure anaerobic digester and pretreated by nutrient acclimation, heat and pH treatment was used as inoculum. High system stability was indicated by a short startup period of 12 days followed by stable hydrogen production, and successful sludge granulation occurred within 23 days of startup at a hydraulic retention time (HRT) of 24 hours. Operation at a progressively decreasing HRT from 24 to 8h gave rise to an increasing biogas production rate from 15.2-34.4L/d, while good linear relationships were observed between both total biogas and hydrogen production rates correlated to HRT, with R2 values of 0.993 and 0.997, respectively. The maximum hydrogen yield of 1.63 mol-H 2/mol-hexose-feed occurred at HRT of 16h, while the HRT of 12h was highly suggested to achieve both high production rate and efficient yield. Hexose utilization efficiencies over 98%, considerable hydrogen production rate up to 14.3 L/d and hydrogen percentage of off-gas up to 43% (i.e., a CO 2/H2 ratio of 1.2) with the absence of CH4 production throughout the whole course of experiment at a pH of 5.0 strongly validated the feasibility of the fermentative H2 production from liquid swine manure using an ASBR system. Ethanol as well as acetic, butyric and valeric acids were produced in the system accompanying the hydrogen production, with acetic acid being the dominant

  10. 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

  11. Analysis of denitrifier community in a bioaugmented sequencing batch reactor for the treatment of coking wastewater containing pyridine and quinoline

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yaohui; Xing, Rui; Wen, Donghui; Tang, Xiaoyan [Peking Univ., Beijing (CN). Key Lab. of Water and Sediment Sciences (Ministry of Education); Sun, Qinghua [Peking Univ., Beijing (CN). Key Lab. of Water and Sediment Sciences (Ministry of Education); Chinese Center for Disease Control and Prevention, Beijing (China). Inst. of Environmental Health and Related Product Safety

    2011-05-15

    The denitrifier community and associated nitrate and nitrite reduction in the bioaugmented and general sequencing batch reactors (SBRs) during the treatment of coking wastewater containing pyridine and quinoline were investigated. The efficiency and stability of nitrate and nitrite reduction in SBR was considerably improved after inoculation with four pyridine- or quinoline-degrading bacterial strains (including three denitrifying strains). Terminal restriction fragment length polymorphism (T-RFLP) based on the nosZ gene revealed that the structures of the denitrifier communities in bioaugmented and non-bioaugmented reactors were distinct and varied during the course of the experiment. Bioaugmentation protected indigenous denitrifiers from disruptions caused by pyridine and quinoline. Clone library analysis showed that one of the added denitrifiers comprised approximately 6% of the denitrifier population in the bioaugmented sludge. (orig.)

  12. REUSABLE ADSORBENTS FOR DILUTE SOLUTIONS SEPARATION. 6. BATCH AND CONTINUOUS REACTORS FOR ADSORPTION AND DEGRADATION OF 1,2-DICHLOROBENZENE FROM DILUTE WASTEWATER STREAMS USING TITANIA AS A PHOTOCATALYST. (R828598C753)

    Science.gov (United States)

    Two types of external lamp reactors were investigated for the titania catalyzed photodegradation of 1,2-dichlorobenzene (DCB) from a dilute water stream. The first one was a batch mixed slurry reactor and the second one was a semi-batch reactor with continuous feed recycle wit...

  13. Denitrifying capability and community dynamics of glycogen accumulating organisms during sludge granulation in an anaerobic-aerobic sequencing batch reactor

    Science.gov (United States)

    Bin, Zhang; Bin, Xue; Zhigang, Qiu; Zhiqiang, Chen; Junwen, Li; Taishi, Gong; Wenci, Zou; Jingfeng, Wang

    2015-08-01

    Denitrifying capability of glycogen accumulating organisms (GAOs) has received great attention in environmental science and microbial ecology. Combining this ability with granule processes would be an interesting attempt. Here, a laboratory-scale sequencing batch reactor (SBR) was operated to enrich GAOs and enable sludge granulation. The results showed that the GAO granules were cultivated successfully and the granules had denitrifying capability. The batch experiments demonstrated that all NO3--N could be removed or reduced, some amount of NO2--N were accumulated in the reactor, and N2 was the main gaseous product. SEM analysis suggested that the granules were tightly packed with a large amount of tetrad-forming organisms (TFOs); filamentous bacteria served as the supporting structures for the granules. The microbial community structure of GAO granules was differed substantially from the inoculant conventional activated sludge. Most of the bacteria in the seed sludge grouped with members of Proteobacterium. FISH analysis confirmed that GAOs were the predominant members in the granules and were distributed evenly throughout the granular space. In contrast, PAOs were severely inhibited. Overall, cultivation of the GAO granules and utilizing their denitrifying capability can provide us with a new approach of nitrogen removal and saving more energy.

  14. The Study Effect of Fill and React Period Change on the Performance of the Sequencing Batch Reactor

    Directory of Open Access Journals (Sweden)

    Azwar Azwar

    2009-06-01

    Full Text Available The operation of the sequencing batch reactor (SBR can be optimized by controlling the dissolved oxygen concentration, the dosage of external carbon, nitrification and denitrification, and the phase length of aeration (fills and react period. In this work, the analyses and tested with open loop identification the effect of fill and react period change on the performance of the SBR were studied. The process dynamic has been tested to determine the effect of Fill (tf and React (trperiod changes on soluble substrate (Ss, soluble intermediate product (Ps, inert substrate (Si, particulate organics concentration (Xs, active biomass concentration (Xa, inert biomass concentration (Xi, the total biomass concentration (Xto and the effluent chemical oxygen demand (COD concentration in the SBR. In all simulations the total Fill and React time were set at 6 h, with the Fill time varied at 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, and the corresponding react time set at 5.5 h, 5 h, 4.5 h, 4 h, 3.5 h, and 3 h, respectively. Keywords: fill time and reaction time, sequencing batch reactor, wastewater treatment

  15. Scalable synthesis of ionic liquids: comparison of performances of microstructured and stirred batch reactors

    OpenAIRE

    Iken, Hicham; Guillen, Frédéric; Chaumat, Hélène; Mazières, Marie-Rose; Plaquevent, Jean-Christophe; Tzedakis, Théodore

    2012-01-01

    A range of alkylpyridinium bromide ionic liquids have been synthesized in a stirred reactor at multigram scale and characterized by physical methods (viscosity, conductivity, melting point, electrochemical window, and water content). One ionic liquid, octylpyridinium bromide, was chosen to be synthesized in both macro and reduced scale reactors, in order to compare its performance and to afford evidence of the advantages of a cross channel micro reactor (channel width = 1 mm) compared to a st...

  16. A MINI SCALE REACTOR FOR BATCH PRODUCTION OF PALM BASED POLYOL

    OpenAIRE

    Badri, K.H.; M. S. Ngah

    2015-01-01

    An investigation on a batch production of palm kernel oil polyol (PKO-p) was conducted via esterification and condensation.The process design was thoroughly studied as a preliminary step for future upscaling. The process variables included necessity of vacuum pump, controlling of heating rate, recording the production time, nitrogen gas flow and agitator speed. About 250 ml PKO-p was successfully synthesized within 3 h. Vacuum pressure was applied to haul out moisture from the sys...

  17. Multivariable statistical process control to situation assessment of a sequencing batch reactor

    OpenAIRE

    Ruiz Ordóñez, Magda; Colomer, Joan; Colprim, Jesus; Meléndez, Joaquim

    2004-01-01

    In this work, a combination between Multivariate Statistical Process Control (MSPC) and an automatic classification algorithm is developed to application in Waste Water Treatment Plant. Multiway Principal Component Analysis is used as MSPC method. The goal is to create a model that describes the batch direction and helps to fix the limits used to determine abnormal situations. Then, an automatic classification algorithm is used to situation assessment of the process.

  18. About the performance of Sphaerotilus natans to reduce hexavalent chromium in batch and continuous reactors

    International Nuclear Information System (INIS)

    The hexavalent chromium biological reduction constitutes a safe and economical detoxification procedure of wastewaters containing Cr(VI). However, little research has been done to evaluate Cr(VI) tolerance and reduction capacity of microbial cultures under different growth conditions. The aims of this work were (a) to evaluate the capacity of Sphaerotilus natans to reduce Cr(VI) to Cr(III) in a continuous system limited in carbon and energy source or in nitrogen source, (b) to evaluate the toxic effect of Cr(VI) on this microorganism, (c) to carry out a complete analysis of Cr(VI) reduction by S. natans not only in continuous regime but also in batch system, and (d) to model the obtained results mathematically. S. natans exhibited great resistance to Cr(VI) (19-78 mg l-1) and optimal growth in continuous and batch systems using a mineral medium supplemented only with citric acid as organic substrate. In carbon- and energy-limited continuous systems, a maximum percentual decrease in Cr(VI) by 13% was reached for low influent Cr(VI) concentration (4.3-5.32 mgCr(VI) l-1); the efficiency of the process did not notoriously increase as the length of cellular residence time was increased from 4.16 to 50 h. A nitrogen-limited continuous operation with a cellular residence time of 28.5 h resulted in a Cr(VI) decrease of approximately 26-32%. In batch system, a mathematical model allowed to predict the Cr(VI) concentration as a function of time and the ratio between the initial Cr(VI) concentration and that of the biomass. High concentrations of initial Cr(VI) and biomass produced the highest performance of the process of Cr(VI) reduction reached in batch system, aspects which should be considered in detoxification strategies of wastewaters.

  19. OPTIMIZATION OF HYDRAULIC RETENTION TIME (HRT FOR RAW SUGARMILL WASTEWATER USING ANAEROBIC SEQUENTIAL BATCH REACTOR (AnSBR

    Directory of Open Access Journals (Sweden)

    Dr. S. JAYANTHI

    2013-04-01

    Full Text Available Sugar Industries in India generate about 1000 litres of wastewater for every tonne of sugarcane crushed during the manufacturing process of white crystals i.e. Sugar. There are various biological treatments for treating the wastewater of which here AnSBR is used. Anaerobic Sequential Batch Reactor (AnSBR was operated in mesophillic condition (27°C - 35°C for the treatment of Sugar mill wastewater. The study was initiated by studying the characteristics of the wastewater for the parameters such as pH, Chlorides, Acidity, Alkalinity, Total Solids, Suspended Solids, Total Dissolve Solids, Volatile Solids, Chemical Oxygen Demand (COD and Volatile Fatty Acids. The treatment of the sugar mill wastewater for the production of bio-methane gas is to be carried out in AnSBR at lab scale at room temperature with a volume of 3.5 Litres. The reactors are to be operated in 8 hours cyclic steps for different Hydraulic Retention Time (HRT such as 36, 48 and 72. Four steps involved during the 8 hours operation a Feeding Time (10 mins b Decanting time (10 mins c Reaction time (5.6 hours d Settling time (2 hours. AnSBR was operated in 8hr cyclic steps for 36, 48, 72 hrs HRT. The efficiency of the reactor was determined on basis of the maximum gas production by varying sequence lengths.OLR and HRTs. After 30 days, the AnSBR reactor could able to start with successful granulation. Optimum HRT was found to be 48 hrs at optimum HRT the COD removal % of 92 with a gas yield of 6.7828 L/L.day. The performance of reactor was considerably increased to a tune of 92%.

  20. The Effect of Initial Inoculum Source on the Microbial Community Structure and Dynamics in Laboratory-Scale Sequencing Batch Reactors

    KAUST Repository

    Hernandez, Susana

    2011-07-01

    Understanding the factors that shapes the microbial community assembly in activated sludge wastewater treatment processes provide a conceptual foundation for improving process performance. The aim of this study was to compare two major theories (deterministic theory and neutral theory) regarding the assembly of microorganisms in activated sludge: Six lab-scale activated sludge sequencing batch reactors were inoculated with activated sludge collected from three different sources (domestic, industrial, and sugar industry WWTP). Additionally, two reactors were seeded with equal proportion of sludge from the three WWTPs. Duplicate reactors were used for each sludge source (i.e. domestic, industrial, sugar and mix). Reactors were operated in parallel for 11 weeks under identical conditions. Bacterial diversity and community structure in the eight SBRs were assessed by 16S rRNA gene pyrosequencing. The 16S rRNA gene sequences were analyzed using taxonomic and clustering analysis and by measuring diversity indices (Shannon-weaver and Chao1 indices). Cluster analysis revealed that the microbial community structure was dynamic and that replicate reactors evolved differently. Also the microbial community structure in the SBRs seeded with a different sludge did not converge after 11 weeks of operation under identical conditions. These results suggest that history and distribution of taxa in the source inoculum were stronger regulating factors in shaping bacterial community structure than environmental factors. This supports the neutral theory which states that the assembly of the local microbial community from the metacommunity is random and is regulated by the size and diversity of the metacommunity. Furthermore, sludge performance, measured by COD and ammonia removal, confirmed that broad-scale functions (e.g. COD removal) are not influenced by dynamics in the microbial composition, while specific functions (e.g. nitrification) are more susceptible to these changes.

  1. Evaluation of kojic acid production in a repeated-batch PCS biofilm reactor.

    Science.gov (United States)

    Liu, Jui-Ming; Yu, Ting-Chu; Lin, Shin-Ping; Hsu, Ren-Jun; Hsu, Kai-Di; Cheng, Kuan-Chen

    2016-01-20

    In this study, kojic acid, a secondary metabolite as an industrially important compound, was produced by Aspergillus oryzae (A. oryzae), which was immobilized in plastic composite support (PCS) bioreactor. Nitrogen deficient medium was applied to increase the production of KA in PCS-immobilized bioreactor. The efficiency of immobilized culture for kojic acid (KA) production and the effect of morphology of A. oryzae on KA production were evaluated. After three cycles of cultivation, 83.47 g/L of KA was produced in PCS bioreactor in nitrogen deficient medium with productivity of 3.09 g/L/d, which is higher than free suspension culture in batch fermentation. The morphology of A. oryzae mycelium changed under nitrogen starvation. Feather-like mycelium was observed with increasing KA production. RNA expression (kojA and kojT) results indicated that the nitrogen deficient environment had strong influence on KA production on the transcriptional level. PCS immobilized fermentation system, which allowed a repeated-batch fermentation with higher production and productivity, is a potential tool in industrial production of KA. PMID:26657710

  2. Tratamiento del Colorante Azo Rojo Directo 23 mediante Reactores Discontinuos Secuenciados Anaerobios/Aerobios Treatment of Direct Red 23 Azo Dye by Anaerobic/Aerobic Sequencing Batch Reactors

    Directory of Open Access Journals (Sweden)

    Fernanda Morales-Guzmán

    2009-01-01

    Full Text Available Se evaluó el tratamiento del colorante azo Rojo Directo 23 mediante un proceso anaerobio/aerobio integrado en un sólo reactor. Se utilizaron dos reactores: uno de lecho expandido con carbón activado granular como mediador redox y otro conteniendo la biomasa suspendida, ambos operados en discontinuo. Se evaluó la eficiencia del proceso mediante la reducción y transformación del colorante a aminas aromáticas totales en la fase anaerobia y la degradación de éstas en la fase aerobia. La eliminación del colorante fue por microorganismos y no por adsorción en el carbón activado granular. Las concentraciones de colorante utilizadas fueron de 25 a 100 mg L-1. En el reactor de lecho expandido la eficiencia de degradación global del colorante fue del 90 % y la eliminación de las aminas formadas fue del 100 %.The treatment of the azo dye Direct Red 23 was evaluated by an anaerobic/aerobic process done in a single reactor. Two reactors were used: one was an expanded-bed with granular activated carbon as redox mediator and the other containing the suspended biomass, both operated in batch mode. The efficiency of the process was evaluated by the reduction and transformation of the azo dye to total aromatic amines in the anaerobic phase and the degradation of these in the aerobic phase. The elimination of azo dye direct red was by microorganisms and not by adsorption in the granular activated carbon. The concentration of azo dye used was of 25 to 100 mg L-¹. In the expanded-bed reactor the removal efficiency of the dye was 90 % and the elimination of the amines formed was of 100 %.

  3. Degradation kinetics of the main carbohydrates in birch wood during hot water extraction in a batch reactor at elevated temperatures.

    Science.gov (United States)

    Borrega, Marc; Nieminen, Kaarlo; Sixta, Herbert

    2011-11-01

    Hot water extraction of wood at elevated temperatures may be a suitable method to produce hemicellulose-lean pulps and to recover xylan-derived products from the water extract. In this study, water extractions of birch wood were conducted at temperatures between 180 and 240 °C in a batch reactor. Xylan was extensively removed, whereas cellulose was partly degraded only at temperatures above 180 °C. Under severe extraction conditions, acetic acid content in the water extract was higher than the corresponding amount of acetyl groups in wood. In addition to oligo- and monosaccharides, considerable amounts of furfural and 5-hydroxymethylfurfural (HMF) were recovered from the extracts. After reaching a maximum, the furfural yield remained constant with increasing extraction time. This maximum slightly decreased with increasing extraction temperature, suggesting the preferential formation of secondary degradation products from xylose. Kinetic models fitting experimental data are proposed to explain degradation and conversion reactions of xylan and glucan. PMID:21967712

  4. Influence of the agitation rate on the treatment of partially soluble wastewater in anaerobic sequencing batch biofilm reactor.

    Science.gov (United States)

    Pinho, Samantha Cristina; Ratusznei, Suzana Maria; Rodrigues, José Alberto Domingues; Foresti, Eugenio; Zaiat, Marcelo

    2004-11-01

    This work reports on the influence of the agitation rate on the organic matter degradation in an anaerobic sequencing batch reactor, containing biomass immobilized on 3 cm cubic polyurethane matrices, stirred mechanically and fed with partially soluble soymilk substrate with mean chemical oxygen demand (COD) of 974+/-70 mg l(-1). Hydrodynamic studies informed on the homogenization time under agitagion rates from 500 to 1100 rpm provided by three propeller impellers. It occurred very quickly compared to the total cycle time. The results showed that agitation provided good mixing and improved the overall organic matter consumption rates. A modified first-order kinetic model represented adequately the data in the entire range of agitation rate. The apparent first-order kinetic constant for suspended COD rose approximately 360% when the agitation rate was changed from 500 to 900 rpm, whereas the apparent first-order kinetic constant for soluble COD did not vary significantly. PMID:15491659

  5. Anaerobic co-digestion of sewage sludge and sugar beet pulp lixiviation in batch reactors: effect of temperature.

    Science.gov (United States)

    Montañés, Rocío; Solera, Rosario; Pérez, Montserrat

    2015-03-01

    The feasibility of anaerobic co-digestion of sewage sludge (SS) and sugar beet pulp lixiviation (SBPL) was assessed. Mesophilic and thermophilic batch assays of five different SS/SBPL ratios were used to investigate the effect of temperature, providing basic data on methane yield and reduction in total volatiles. Microbe concentrations (Eubacteria and methanogenic Archaea) were linked to traditional parameters, namely biogas production and removal of total volatile solids (TVS). The relationship between Eubacteria and Archaea was analysed. Given equal masses of organic matter, net methane generation was higher in the mesophilic range on the biochemical methane potential (BMP) test. Methane yield, TVS removal data and high levels of volatile fatty acids provided further evidence of the best behaviour of the mesophilic range. At the end of testing the microbial population under of the reactors consisted of Eubacteria and Archaea, with Eubacteria predominant in all cases. PMID:25600010

  6. Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor.

    Science.gov (United States)

    Kong, Qiang; Ngo, Huu Hao; Shu, Li; Fu, Rong-Shu; Jiang, Chun-Hui; Miao, Ming-sheng

    2014-08-30

    This study elucidates the enhancement of aerobic granulation by zero-valent iron (ZVI). A reactor augmented with ZVI had a start-up time of aerobic granulation (43 days) that was notably less than that for a reactor without augmentation (64 days). The former reactor also had better removal efficiencies for chemical oxygen demand and ammonium. Moreover, the mature granules augmented with ZVI had better physical characteristics and produced more extracellular polymeric substances (especially of protein). Three-dimensional-excitation emission matrix fluorescence showed that ZVI enhanced organic material diversity. Additionally, ZVI enhanced the diversity of the microbial community. Fe(2+) dissolution from ZVI helped reduce the start-up time of aerobic granulation and increased the extracellular polymeric substance content. Conclusively, the use of ZVI effectively enhanced aerobic granulation. PMID:25108827

  7. Modeling and monitoring cyclic and linear volatile methylsiloxanes in a wastewater treatment plant using constant water level sequencing batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, De-Gao, E-mail: degaowang@dlmu.edu.cn; Du, Juan; Pei, Wei; Liu, Yongjun; Guo, Mingxing

    2015-04-15

    The fate of cyclic and linear volatile methylsiloxanes (VMSs) was evaluated in a wastewater treatment plant (WWTP) using constant water level sequencing batch reactors from Dalian, China. Influent, effluent, and sewage sludge samples were collected for seven consecutive days. The mean concentrations of cyclic VMSs (cVMSs) in influent and effluent samples are 1.05 μg L{sup −1} and 0.343 μg L{sup −1}; the total removal efficiency of VMSs is > 60%. Linear VMS (lVMS) concentration is under the quantification limitation in aquatic samples but is found in sludge samples with a value of 90 μg kg{sup −1}. High solid-water partition coefficients result in high VMS concentrations in sludge with the mean value of 5030 μg kg{sup −1}. No significant differences of the daily mass flows are found when comparing the concentration during the weekend and during working days. The estimated mass load of total cVMSs is 194 mg d{sup −1} 1000 inhabitants{sup −1} derived for the population. A mass balance model of the WWTP was developed and derived to simulate the fate of cVMSs. The removal by sorption on sludge increases, and the volatilization decreases with increasing hydrophobicity and decreasing volatility for cVMSs. Sensitivity analysis shows that the total suspended solid concentration in the effluent, mixed liquor suspended solid concentration, the sewage sludge flow rate, and the influent flow rate are the most influential parameters on the mass distribution of cVMSs in this WWTP. - Highlights: • A mass balance model for siloxanes was developed in sequencing batch reactor. • Total suspended solid in effluent has the most influence on removal efficiency. • Enhancement of suspended solid removal reduces the release to aquatic environment.

  8. Modeling and monitoring cyclic and linear volatile methylsiloxanes in a wastewater treatment plant using constant water level sequencing batch reactors

    International Nuclear Information System (INIS)

    The fate of cyclic and linear volatile methylsiloxanes (VMSs) was evaluated in a wastewater treatment plant (WWTP) using constant water level sequencing batch reactors from Dalian, China. Influent, effluent, and sewage sludge samples were collected for seven consecutive days. The mean concentrations of cyclic VMSs (cVMSs) in influent and effluent samples are 1.05 μg L−1 and 0.343 μg L−1; the total removal efficiency of VMSs is > 60%. Linear VMS (lVMS) concentration is under the quantification limitation in aquatic samples but is found in sludge samples with a value of 90 μg kg−1. High solid-water partition coefficients result in high VMS concentrations in sludge with the mean value of 5030 μg kg−1. No significant differences of the daily mass flows are found when comparing the concentration during the weekend and during working days. The estimated mass load of total cVMSs is 194 mg d−1 1000 inhabitants−1 derived for the population. A mass balance model of the WWTP was developed and derived to simulate the fate of cVMSs. The removal by sorption on sludge increases, and the volatilization decreases with increasing hydrophobicity and decreasing volatility for cVMSs. Sensitivity analysis shows that the total suspended solid concentration in the effluent, mixed liquor suspended solid concentration, the sewage sludge flow rate, and the influent flow rate are the most influential parameters on the mass distribution of cVMSs in this WWTP. - Highlights: • A mass balance model for siloxanes was developed in sequencing batch reactor. • Total suspended solid in effluent has the most influence on removal efficiency. • Enhancement of suspended solid removal reduces the release to aquatic environment

  9. Evaluation of the microbial diversity in sequencing batch reactor treating linear alkylbenzene sulfonate under denitrifying and mesophilic conditions using swine sludge as inoculum

    OpenAIRE

    Iolanda Cristina Silveira Duarte; Lorena Lima de Oliveira; Dagoberto Yukio Okada; Pierre Ferreira do Prado; Maria Bernadete Amâncio Varesche

    2015-01-01

    The objective of this study was to evaluate the degradation of Linear Alkylbenzene Sulfonate (LAS) in anaerobic sequencing batch reactor (ASBR) under denitrifying conditions using swine sludge as inoculum. The reactor was operated for 104 days with synthetic substrate containing nitrate, and LAS was added later (22 mg/L). Considering the added mass of the LAS, the adsorbed mass in the sludge and discarded along with the effluent, degradation of the surfactant at the end of operation was 87%, ...

  10. Investigating Nitrosomonas europaea stress biomarkers in batch, continuous culture, and biofilm reactors.

    Science.gov (United States)

    Radniecki, Tyler S; Lauchnor, Ellen G

    2011-01-01

    The understanding of nitrification inhibition in ammonia oxidizing bacteria (AOB) by priority pollutants and emerging contaminants is critical in managing the nitrogen cycle to preserve current water supplies, one of the National Academy of Engineers Grand Challenges in Engineering for the twenty-first century. Nitrosomonas europaea is an excellent model AOB for nitrification inhibition experimentation due to its well-defined NH(3) metabolism and the availability of a wide range of physiological and transcriptional tools that can characterize the mechanism of nitrification inhibition and probe N. europaea's response to the inhibitor. This chapter is a compilation of the physiological and transcriptional methods that have been used to characterize nitrification inhibition of N. europaea under a wide variety of growth conditions including batch, continuously cultured, and in biofilms. The protocols presented here can be applied to other AOB, and may be readily adapted for other autotrophic bacteria (e.g., nitrite oxidizing bacteria). PMID:21514466

  11. Nitrate Removal from Wastewater through Biological Denitrification with OGA 24 in a Batch Reactor

    Directory of Open Access Journals (Sweden)

    Federico Rossi

    2014-12-01

    Full Text Available Nitrates pollution of waters is a worldwide problem and its remediation is a big challenge from the technical and the scientific point of view. One of the most used and promising cleaning techniques is the biological treatment of wastewaters operated by denitrifying bacteria. In this paper we begin a thorough study of denitrifying performances of the bacterium Azospira sp. OGA 24, recently isolated from the highly polluted Sarno river in the south of Italy. Here, the kinetics of nitrates consumption operated by bacteria in a specifically devised batch bioreactor, in anoxic condition and with acetate as the organic substrate, has been characterized. Experimental data were then used in a simplified model of a real wastewater treatment plant to find that OGA 24 can clean water with efficiency up to 90%. The denitrifying performances of OGA 24 match the requirements of Italian laws and make the bacterium suitable for its employment in treatment plants.

  12. Kinetics and dynamic modelling of batch anaerobic digestion of municipal solid waste in a stirred reactor.

    Science.gov (United States)

    Nopharatana, Annop; Pullammanappallil, Pratap C; Clarke, William P

    2007-01-01

    A series of batch, slurry anaerobic digestion experiments were performed where the soluble and insoluble fractions, and unwashed MSW were separately digested in a 200l stirred stainless steel vessel at a pH of 7.2 and a temperature of 38 degrees C. It was found that 7% of the total MSW COD was readily soluble, of which 80% was converted to biogas; 50% of the insoluble fraction was solubilised, of this only 80% was converted to biogas. The rate of digesting the insoluble fraction was about four times slower than the rate of digesting the soluble fraction; 48% of the total COD was converted to biogas and 40% of the total nitrogen was converted to ammonia. Soluble and insoluble fractions were broken down simultaneously. The minimum time to convert 95% of the degradable fraction to biogas was 20 days. The lag phase for the degradation of insoluble fraction of MSW can be overcome by acclimatising the culture with the soluble fraction. The rate of digestion and the methane yield was not affected by particle size (within the range of 2-50mm). A dynamic model was developed to describe batch digestion of MSW. The parameters of the model were estimated using data from the separate digestion of soluble and insoluble fractions and validated against data from the digestion of unwashed MSW. Trends in the specific aceticlastic and formate-utilising methanogenic activity were used to estimate initial methanogenic biomass concentration and bacterial death rate coefficient. The kinetics of hydrolysis of insoluble fraction could be adequately described by a Contois equation and the kinetics of acidogenesis, and aceticlastic and hydrogen utilising methanogenesis by Monod equations. PMID:16797956

  13. Optimisation of the reaction parameters in a batch reactor and a CSTR for the recovery of phenol from hydrothermal biomass liquefaction

    OpenAIRE

    Forchheim, Daniel

    2014-01-01

    This work deals with the hydrothermal liquefaction of lignin. The focus laid on the discovery of the main reaction pathways within the depolymerisation of lignin-macromolecules and the discovery of bottleneck reactions. This was achieved by literature study and experimental work in both batch and continuous reactor. Modelling of the formal kinetics of the discovered reactions facilitated the evaluation of experimental results.

  14. Effect of the C:N:P ratio on the denitrifying dephosphatation in a sequencing batch biofilm reactor (SBBR).

    Science.gov (United States)

    Mielcarek, Artur; Rodziewicz, Joanna; Janczukowicz, Wojciech; Thornton, Arthur J; Jóźwiak, Tomasz; Szymczyk, Paula

    2015-12-01

    A series of investigations were conducted using sequencing batch biofilm reactor (SBBR) to explore the influence of C:N:P ratio on biological dephosphatation including the denitrifying dephosphatation and the denitrification process. Biomass in the reactor occurred mainly in the form of a biofilm attached to completely submerged disks. Acetic acid was used as the source of organic carbon. C:N:P ratios have had a significant effect on the profiles of phosphate release and phosphate uptake and nitrogen removal. The highest rates of phosphate release and phosphate uptake were recorded at the C:N:P ratio of 140:70:7. The C:N ratio of 2.5:1 ensured complete denitrification. The highest rate of denitrification was achieved at the C:N:P ratio of 140:35:7. The increase of nitrogen load caused an increase in phosphates removal until a ratio C:N:P of 140:140:7. Bacteria of the biofilm exposed to alternate conditions of mixing and aeration exhibited enhanced intracellular accumulation of polyphosphates. Also, the structure of the biofilm encouraged anaerobic-aerobic as well as anoxic-anaerobic and absolutely anaerobic conditions in a SBBR. These heterogeneous conditions in the presence of nitrates may be a significant factor determining the promotion of denitrifying polyphosphate accumulating organism (DNPAO) development. PMID:26702975

  15. Efficiency influence of exogenous betaine on anaerobic sequencing batch biofilm reactor treating high salinity mustard tuber wastewater.

    Science.gov (United States)

    He, Qiang; Kong, Xiang-Juan; Chai, Hong-Xiang; Fan, Ming-Yu; Du, Jun

    2012-01-01

    When treating a composite mustard tuber wastewater with high concentrations of salt (about 20 g Cl(-) L(-1)) and organics (about 8000 mg L(-1) COD) by an anaerobic sequencing batch biofilm reactor (ASBBR) in winter, both high salinity and low temperature will inhibit the activity of anaerobic microorganisms and lead to low treatment efficiency. To solve this problem, betaine was added to the influent to improve the activity of the anaerobic sludge, and an experimental study was carried to investigate the influence of betaine on treating high salinity mustard tuber wastewater by the ASBBR. The results show that, when using anaerobic acclimated sludge in the ASBBR, and controlling biofilm density at 50% and water temperature at 8-12 degrees C, the treatment efficiency of the reactor could be improved by adding the betaine at different concentrations. The efficiency reached the highest when the optimal dosage ofbetaine was 0.5 mmol L(-1). The average effluent COD, after stable acclimation, was 4461 mg L(-1). Relative to ASBBR without adding betaine, the activity of the sludge increased significantly. Meanwhile, the dehydrogenase activity of anaerobic microorganisms and the COD removal efficiency were increased by 18.6% and 18.1%, respectively. PMID:22988630

  16. Effect of continuously dosing Cu(II) on pollutant removal and soluble microbial products in a sequencing batch reactor.

    Science.gov (United States)

    Yan, YangWei; Wang, YuWen; Liu, Yan; Liu, Xiang; Yao, ChenChao; Ma, LuMing

    2015-01-01

    The effects of synthetic wastewater that contained 20 mg/L Cu(II) on the removal of organic pollutants in a sequencing batch reactor were investigated. Results of continuous 20 mg/L Cu(II) exposure for 120 days demonstrated that the chemical oxygen demand (COD) removal efficiency decreased to 42% initially, followed by a subsequent gradual recovery, which peaked at 78% by day 97. Effluent volatile fatty acid (VFA) concentration contributed 67 to 89% of the influent COD in the experimental reactor, which indicated that the degradation of the organic substances ceased at the VFA production step. Meanwhile, the varieties of soluble microbial products (SMP) content and main components (protein, polysaccharide, and DNA) were discussed to reveal the response of activated sludge to the toxicity of 20 mg/L Cu(II). The determination of Cu(II) concentrations in extracellular polymeric substances (EPS) and SMP throughout the experiment indicated an inverse relationship between extracellular Cu(II) concentration and COD removal efficiency. PMID:26524458

  17. Shut-cut nitrification characteristics of aerobic granule in a sequencing batch airlift reactor at low temperature

    Institute of Scientific and Technical Information of China (English)

    BAO Rui-ling; YU Shui-li; ZUO Xing-tao; WANG Juan

    2009-01-01

    To investigate the shut-cut nitrification characteristics of aerobic granule, an aerobic granular se-quencing batch airlift reactor (AG-SBAR) was carried out with mixed carbon sources of sodium acetate and glu-cose at 10± 1℃. Results indicated that ammonia oxidizing bacteria was accumulated inside the aerobic gran-ules and the reactor performed stably with shut-cut nitrification for a long term at low temperature. During the stable operation period, the effluent ammonia nitrogen concentration was maintained at 13.6 mg/L without ni-trate and nitrite when the COD/N ratio was 20: 1. However, the effluent concentration of ammonia nitrogen was below 0. 5 mg/L with effluent nitrosation ratio of 96. 7% on average when the COD/N ratio was reduced to 15:1 and 10: 1. And the effluent phosphorus concentration was less than 0. 4 mg/L during the stable period with the sludge retention time of 30 d. The phosphorus removal efficiency was not strongly influenced by the adjust-ment of COD/N ratio in this experiment. The removal efficiencies for COD, NH4+-N and PO43--P were 91.3%-94. 6%, 97.9%-99. 7% and 97. 1%-99. 5%, respectively.

  18. 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.

  19. Pyrolysis of biomass and refuse-derived fuel performance in laboratory scale batch reactor

    OpenAIRE

    Kluska Jacek; Klein Marek; Kazimierski Paweł; Kardaś Dariusz

    2014-01-01

    The results of pyrolysis of pine chips and refuse derived fuel fractions are presented. The experiments were carried out in a pilot pyrolysis reactor. The feedstock was analyzed by an elemental analyzer and the X-ray fluorescence spectrometer to determine the elemental composition. To find out optimum conditions for pyrolysis and mass loss as a function of temperature the thermogravimetric analysis was applied. Gases from the thermogravimetric analysis were directed to the infrared spectromet...

  20. Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Qiang, E-mail: kongqiang0531@hotmail.com [College of Life Science, Shandong Normal University, 88 Wenhua Donglu, Jinan 250014, Shandong (China); Ngo, Huu Hao [School of Civil and Environmental Engineering, University of Technology Sydney, Broadway, NSW 2007 (Australia); Shu, Li [School of Engineering, Faculty of Science, Engineering and Built Environment, Deakin University, Geelong, Victoria 3216 (Australia); Fu, Rong-shu; Jiang, Chun-hui [College of Life Science, Shandong Normal University, 88 Wenhua Donglu, Jinan 250014, Shandong (China); Miao, Ming-sheng, E-mail: mingshengmiao@163.com [College of Life Science, Shandong Normal University, 88 Wenhua Donglu, Jinan 250014, Shandong (China)

    2014-08-30

    Highlights: • Zero-valent iron (ZVI) was used firstly to enhance the aerobic granulation. • ZVI significantly decreased the start-up time of the aerobic granulation. • ZVI had the function of enhancing organic material diversity identified by 3-D EEM. • ZVI could enhance the diversity of microbial community. - Abstract: This study elucidates the enhancement of aerobic granulation by zero-valent iron (ZVI). A reactor augmented with ZVI had a start-up time of aerobic granulation (43 days) that was notably less than that for a reactor without augmentation (64 days). The former reactor also had better removal efficiencies for chemical oxygen demand and ammonium. Moreover, the mature granules augmented with ZVI had better physical characteristics and produced more extracellular polymeric substances (especially of protein). Three-dimensional-excitation emission matrix fluorescence showed that ZVI enhanced organic material diversity. Additionally, ZVI enhanced the diversity of the microbial community. Fe{sup 2+} dissolution from ZVI helped reduce the start-up time of aerobic granulation and increased the extracellular polymeric substance content. Conclusively, the use of ZVI effectively enhanced aerobic granulation.

  1. Enhancement of aerobic granulation by zero-valent iron in sequencing batch airlift reactor

    International Nuclear Information System (INIS)

    Highlights: • Zero-valent iron (ZVI) was used firstly to enhance the aerobic granulation. • ZVI significantly decreased the start-up time of the aerobic granulation. • ZVI had the function of enhancing organic material diversity identified by 3-D EEM. • ZVI could enhance the diversity of microbial community. - Abstract: This study elucidates the enhancement of aerobic granulation by zero-valent iron (ZVI). A reactor augmented with ZVI had a start-up time of aerobic granulation (43 days) that was notably less than that for a reactor without augmentation (64 days). The former reactor also had better removal efficiencies for chemical oxygen demand and ammonium. Moreover, the mature granules augmented with ZVI had better physical characteristics and produced more extracellular polymeric substances (especially of protein). Three-dimensional-excitation emission matrix fluorescence showed that ZVI enhanced organic material diversity. Additionally, ZVI enhanced the diversity of the microbial community. Fe2+ dissolution from ZVI helped reduce the start-up time of aerobic granulation and increased the extracellular polymeric substance content. Conclusively, the use of ZVI effectively enhanced aerobic granulation

  2. Sequential batch membrane bio-reactor for wastewater treatment: The effect of increased salinity.

    Science.gov (United States)

    Mannina, Giorgio; Capodici, Marco; Cosenza, Alida; Di Trapani, Daniele; Viviani, Gaspare

    2016-06-01

    In this work, a sequential batch membrane bioreactor pilot plant is investigated to analyze the effect of a gradual increase in salinity on carbon and nutrient removal, membrane fouling and biomass kinetic parameters. The salinity was increased by 2gNaClL(-1) per week up to 10gNaClL(-1). The total COD removal efficiency was quite high (93%) throughout the experiment. A gradual biomass acclimation to the salinity level was observed during the experiment, highlighting the good recovery capabilities of the system. Nitrification was also influenced by the increase in salinity, with a slight decrease in nitrification efficiency (the lowest value was obtained at 10gNaClL(-1) due to lower nitrifier activity). Irreversible cake deposition was the predominant fouling mechanism observed during the experiment. Respirometric tests exhibited a stress effect due to salinity, with a reduction in the respiration rates observed (from 8.85mgO2L(-1)h(-1) to 4mgO2L(-1)h(-1)). PMID:26970923

  3. Evaluation of the microbial diversity in sequencing batch reactor treating linear alkylbenzene sulfonate under denitrifying and mesophilic conditions using swine sludge as inoculum

    Directory of Open Access Journals (Sweden)

    Iolanda Cristina Silveira Duarte

    2015-06-01

    Full Text Available The objective of this study was to evaluate the degradation of Linear Alkylbenzene Sulfonate (LAS in anaerobic sequencing batch reactor (ASBR under denitrifying conditions using swine sludge as inoculum. The reactor was operated for 104 days with synthetic substrate containing nitrate, and LAS was added later (22 mg/L. Considering the added mass of the LAS, the adsorbed mass in the sludge and discarded along with the effluent, degradation of the surfactant at the end of operation was 87%, removal of chemical oxygen demand was 86% and nitrate was 98%. The bacterial community was evaluated by cutting the bands and sequencing of polymerase chain reaction (PCR fragments and denaturing gradient gel electrophoresis (DGGE. The sequences obtained were related to the phylum Proteobacteria and the alpha-and beta-proteobacteria classes, these bacteria were probably involved in the degradation of LAS. The efficiently degraded LAS in the reactor was operated in batch sequences in denitrifying conditions.

  4. Comparative study between chemostat and batch reactors to quantify membrane permeability changes on bacteria exposed to silver nanoparticles.

    Science.gov (United States)

    Anaya, Nelson M; Faghihzadeh, Fatemeh; Ganji, Nasim; Bothun, Geoff; Oyanedel-Craver, Vinka

    2016-09-15

    Continuous and batch reactors were used to assess the effect of the exposure of casein-coated silver nanoparticles (AgNPs) on Escherichia coli (E. coli). Additionally, E. coli membrane extracts, membrane permeability and Langmuir film balance assays were used to determine integrity and changes in lipid composition in response to AgNPs exposure. Results showed that batch conditions were not appropriate for the tests due to the production of exopolymeric substances (EPS) during the growth phase. After 5h of contact between AgNPs and the used growth media containing EPS, the nanoparticles increased in size from 86nm to 282nm reducing the stability and thus limiting cell-nanoparticle interactions. AgNPs reduced E. coli growth by 20% at 1mg/L, in terms of Optical Density 670 (OD670), while no effect was detected at 15mg/L. At 50mg/L of AgNPs was not possible to perform the test due to aggregation and sedimentation of the nanoparticles. Membrane extract assays showed that at 1mg/L AgNPs had a greater change in area (-4.4cm(2)) on bacteria compared to 15mg/L (-4.0cm(2)). This area increment suggested that membrane disruption caused by AgNPs had a stabilizing/rigidifying effect where the cells responded by shifting their lipid composition to more unsaturated lipids to counteract membrane rigidification. In chemostats, the constant inflow of fresh media and aeration resulted in less AgNPs aggregation, thus increased the AgNPs-bacteria interactions, in comparison to batch conditions. AgNPs at 1mg/L, 15mg/L, and 50mg/L inhibited the growth (OD670 reduction) by 0%, 11% and 16.3%, respectively. Membrane extracts exposed to 1mg/L, 15mg/L, and 50mg/L of AgNPs required greater changes in area by -0.5cm(2), 2.7cm(2) and 3.6cm(2), respectively, indicating that the bacterial membranes were disrupted and bacteria responded by synthesizing lipids that stabilize or strengthen membranes. This study showed that the chemostat is more appropriate for the testing of nanotoxicological effects

  5. Pyrolysis of biomass and refuse-derived fuel performance in laboratory scale batch reactor

    Directory of Open Access Journals (Sweden)

    Kluska Jacek

    2014-03-01

    Full Text Available The results of pyrolysis of pine chips and refuse derived fuel fractions are presented. The experiments were carried out in a pilot pyrolysis reactor. The feedstock was analyzed by an elemental analyzer and the X-ray fluorescence spectrometer to determine the elemental composition. To find out optimum conditions for pyrolysis and mass loss as a function of temperature the thermogravimetric analysis was applied. Gases from the thermogravimetric analysis were directed to the infrared spectrometer using gas-flow cuvette to online analysis of gas composition. Chemical composition of the produced gas was measured using gas chromatography with a thermal conductivity detector and a flame ionization detector. The product analysis also took into account the mass balance of individual products.

  6. Pyrolysis of biomass and refuse-derived fuel performance in laboratory scale batch reactor

    Science.gov (United States)

    Kluska, Jacek; Klein, Marek; Kazimierski, Paweł; Kardaś, Dariusz

    2014-03-01

    The results of pyrolysis of pine chips and refuse derived fuel fractions are presented. The experiments were carried out in a pilot pyrolysis reactor. The feedstock was analyzed by an elemental analyzer and the X-ray fluorescence spectrometer to determine the elemental composition. To find out optimum conditions for pyrolysis and mass loss as a function of temperature the thermogravimetric analysis was applied. Gases from the thermogravimetric analysis were directed to the infrared spectrometer using gas-flow cuvette to online analysis of gas composition. Chemical composition of the produced gas was measured using gas chromatography with a thermal conductivity detector and a flame ionization detector. The product analysis also took into account the mass balance of individual products.

  7. Bioleaching of uranium in batch stirred tank reactor: Process optimization using Box–Behnken design

    International Nuclear Information System (INIS)

    Highlights: ► High amount of uranium recovery achieved using Acidithiobacillus ferrooxidans. ► ANOVA shows individual variables and their squares are statistically significant. ► The model can accurately predict the behavior of uranium recovery. ► The model shows that pulp density has the greatest effect on uranium recovery. - Abstract: To design industrial reactors, it is important to identify and optimize the effective parameters of the process. Therefore, in this study, a three-level Box–Behnken factorial design was employed combining with a response surface methodology to optimize pulp density, agitation speed and aeration rate in uranium bioleaching in a stirred tank reactor using a pure native culture of Acidithiobacillus ferrooxidans. A mathematical model was then developed by applying the least squares method using the software Minitab Version 16.1.0. The second order model represents the uranium recovery as a function of pulp density, agitation speed and aeration rate. An analysis of variance was carried out to investigate the effects of individual variables and their combined interactive effects on uranium recovery. The results showed that the linear and quadratic terms of variables were statistically significant whilst the interaction terms were statistically insignificant. The model estimated that a maximum uranium extraction (99.99%) could be obtained when the pulp density, agitation speed and aeration rate were set at optimized values of 5.8% w/v, 510 rpm and 250 l/h, respectively. A confirmatory test at the optimum conditions resulted in a uranium recovery of 95%, indicating a marginal error of 4.99%. Furthermore, control tests were performed to demonstrate the effect of A. ferrooxidans in uranium bioleaching process and showed that the addition of this microorganism greatly increases the uranium recovery

  8. Physiological changes of Candida tropicalis population degrading phenol in fed batch reactor

    Directory of Open Access Journals (Sweden)

    Eliska Komarkova

    2003-12-01

    Full Text Available Candida tropicalis can use phenol as the sole carbon and energy source. Experiments regarding phenol degradations from the water phase were carried out. The fermentor was operated as a fed-batch system with oxistat control. Under conditions of nutrient limitation and an excess of oxygen the respiration activity of cells was suppressed and some color metabolites (black-brown started to be formed. An accumulation of these products inhibited the cell growth under aerobic conditions. Another impact was a decrease of the phenol hydroxylase activity as the key enzyme of the phenol degradation pathway at the end of the cell respiration activity. This decrease is linked with the above mentioned product inhibition. The cell death studied by fluorescent probe proceeded very slowly after the loss of the respiration activity. The starvation stress induced an increase of the endogenous respiration rate at the expense of phenol oxidation.Candida tropicalis pode utilizar fenol como única fonte de carbono e de energia. O fermentador foi operado em um sistema ''batelada-alimentada'' e controle oxidativo. Em condições limitantes de nutrientes e excesso de oxigênio a atividade respiratória das células foi suprimida e o calor do metabolismo pode ser formado. Uma acumulação desses produtos inibiu o crescimento das células em condições aeróbicas. Outro impacto foi um decréscimo da atividade fenol hidroxilase como enzima chave da degradação do fenol no final da atividade respirométrica. Essa redução está relacionada com os fatos acima mencionados. A morte da célula estudada por sonda de fluorescência ocorreu lentamente após a perda da atividade respiratória. O ''stress'' celular induziu um aumento na taxa de respiração endógena devido à oxidação fenólica.

  9. Coupling of acrylic dyeing wastewater treatment by heterogeneous Fenton oxidation in a continuous stirred tank reactor with biological degradation in a sequential batch reactor.

    Science.gov (United States)

    Esteves, Bruno M; Rodrigues, Carmen S D; Boaventura, Rui A R; Maldonado-Hódar, F J; Madeira, Luís M

    2016-01-15

    This work deals with the treatment of a recalcitrant effluent, from the dyeing stage of acrylic fibres, by combination of the heterogeneous Fenton's process in a continuous stirred tank reactor (CSTR) with biological degradation in a sequential batch reactor (SBR). Three different catalysts (a commercial Fe/ZSM-5 zeolite and two distinct Fe-containing activated carbons - ACs - prepared by wet impregnation of iron acetate and iron nitrate) were employed on the Fenton's process, and afterwards a parametric study was carried out to determine the effect of the main operating conditions, namely the hydrogen peroxide feed concentration, temperature and contact time. Under the best operating conditions found, using the activated carbon impregnated with iron nitrate, 62.7% of discolouration and 39.9% of total organic carbon (TOC) reduction were achieved, at steady-state. Furthermore, a considerable increase in the effluent's biodegradability was attained (BOD5:COD ratio increased from toxicity (from 92.1 to 94.0% of Vibrio fischeri inhibition down to 6.9-9.9%). This allowed the application of the subsequent biological degradation stage. The combination of the two processes provided a treated effluent that clearly complies with the legislated discharge limits. It was also found that the iron leaching from the three catalysts tested was very small in all runs, a crucial factor for the stability and long-term use of such materials. PMID:26513317

  10. 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

  11. Quarterly Report, Dec. 1, 1999-Feb. 29, 2000, Novel, Integrated Reactor

    International Nuclear Information System (INIS)

    The basic core design requirements were defined in the previous reporting period. During the second quarter, several series of neutronic calculations were performed. Monte Carlo BOL (Beginning-of-Life) simulations were performed to evaluate the impact of various design alternatives on key core parameters. Fuel design alternatives that were examined by these studies included: fuel form (oxide, carbide and nitride) (note that due to the AMTEC high temperature requirement, metal fuel was eliminated from further considerations); fissile fuel content, and fuel rod and lattice pitch. The key neutronic parameters that were compared include: core reactivity, neutron spectrum, fast neutron flux and projected lifetime fast fluence (E and gt; 0.1 MeV), and material damage indicator, dpa (displacement-per-atom) and dpa rate. These analyses indicated that the fast neutron fluence will probably be the most limiting factor, with estimated fast fluence ranging between 3 x 10(sup 23) n/cm(sup 2) and up to 9 x 10(sup 23) n/cm(sup 2), depending on the fuel characteristics. Therefore, different fuel forms were examined and the projected fast fluence and dpa compared. Using MOX fuel results in the highest fast fluence and dpa, about 10% higher than for the carbide or nitride fuel. The nitride fuel leads to the lowest dpa, for the same reactor power density, up to(approx) 4% and(approx) 7% lower than for the carbide and MOX fuel, respectively

  12. Study of the diversity of microbial communities in a sequencing batch reactor oxic-settling-anaerobic process and its modified process.

    Science.gov (United States)

    Sun, Lianpeng; Chen, Jianfan; Wei, Xiange; Guo, Wuzhen; Lin, Meishan; Yu, Xiaoyu

    2016-05-01

    To further reveal the mechanism of sludge reduction in the oxic-settling-anaerobic (OSA) process, the polymerase chain reaction - denaturing gradient gel electrophoresis protocol was used to study the possible difference in the microbial communities between a sequencing batch reactor (SBR)-OSA process and its modified process, by analyzing the change in the diversity of the microbial communities in each reactor of both systems. The results indicated that the structure of the microbial communities in aerobic reactors of the 2 processes was very different, but the predominant microbial populations in anaerobic reactors were similar. The predominant microbial population in the aerobic reactor of the SBR-OSA belonged to Burkholderia cepacia, class Betaproteobacteria, while those of the modified process belonged to the classes Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. These 3 types of microbes had a cryptic growth characteristic, which was the main cause of a greater sludge reduction efficiency achieved by the modified process. PMID:27021584

  13. The effect of pH and operation mode for COD removal of slaughterhouse wastewater with Anaerobic Batch Reactor (ABR

    Directory of Open Access Journals (Sweden)

    Maria Octoviane Dyan

    2015-01-01

    Full Text Available Disposal of industrial wastes in large quantities was not in accordance with today's standards of waste into environmental issues that must be overcome with proper treatment. Similarly, the abattoir wastewater that contains too high organic compounds and suspended solids. The amount of liquid waste disposal Slaughterhouse (SW with high volume also causes pollution. The research aim to resolve this problem by lowering the levels of BOD-COD to comply with effluent quality standard. Anaerobic process is the right process for slaughterhouse wastewater treatment because of high content of organic compounds that can be utilized by anaerobic bacteria as a growth medium. Some research has been conducted among abattoir wastewater treatment using anaerobic reactors such as ABR, UASB and ASBR. Our research focuses on the search for the optimum results decline effluent COD levels to match the quality standards limbah and cow rumen fluid with biodigester ABR (Anaerobic Batch Reactor. The variables used were PH of 6, 7, and 8, as well as the concentration ratio of COD: N is 400:7; 450:7, and 500:7. COD value is set by the addition of N derived from urea [CO(NH2 2]. COD levels will be measured daily by water displacement technique. The research’s result for 20 days seen that optimum PH for biogas production was PH 7,719 ml. The optimum PH for COD removal is PH 6, 72.39 %. The operation mode COD:N for biogas production and COD removal is 500:7, with the production value is 601 ml and COD removal value is 63.85 %. The research’s conclusion, the PH optimum for biogas production was PH 7, then the optimum PH for COD removal is PH 6. The optimum operation mode COD:N for biogas production and COD removal was 500:7

  14. Effect of inorganic carbon on anaerobic ammonium oxidation enriched in sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    Liao Dexiang; Li Xiaoming; Yang Qi; Zeng Guangming; Guo Liang; Yue Xiu

    2008-01-01

    The present lab-scale research reveals the enrichment of anaerobic ammonium oxidation microorganism from methanogenic anaerobic granular sludge and the effect of inorganic carbon (sodium bicarbonate) on anaerobic ammonium oxidation. The enrichment of anammox bacteria was carried out in a 7.0-L SBR and the effect of bicarbonate on anammox was conducted in a 3.0-L SBR. Research results , especially the biomass, showed first signs of anammox activity after 54 d cultivation with synthetic wastewater, when the pH was controlled between 7.5 and 8.3, the temperature was 35℃. The anammox activity increased as the influent bicarbonate concentration increased from 1.0 to 1.5 g/L and then, was inhibited as the bicarbonate concentration approached 2.0 g/L. However, the activity could be restored by the reduction of bicarbonate concentration to 1.0 g/L, as shown by rapid conversion of ammonium, and nitrite and nitrate production with normal stoichiometry. The optimization of the bicarbonate concentration in the reactor could increase the anammox rate up to 66.4 mgN/(L·d).

  15. Using Sulfate-Amended Sediment Slurry Batch Reactors to Evaluate Mercury Methylation

    International Nuclear Information System (INIS)

    In the methylated form, mercury represents a concern to public health primarily through the consumption of contaminated fish tissue. Research conducted on the methylation of mercury strongly suggests the process is microbial in nature and facilitated principally by sulfate-reducing bacteria. This study addressed the potential for mercury methylation by varying sulfate treatments and wetland-based soil in microbial slurry reactors with available inorganic mercury. Under anoxic laboratory conditions conducive to growth of naturally occurring sulfate-reducing bacteria in the soil, it was possible to evaluate how various sulfate additions influenced the methylation of inorganic mercury added to overlying water. Treatments included sulfate amendments ranging FR-om 25 to 500 mg/L (0.26 to 5.2 mM) above the soil's natural sulfate level. This study also provided an assessment of mercury methylation relative to sulfate-reducing bacterial population growth and subsequent sulfide production. Mercury methylation in sulfate treatments did not exceed that of the non-amended control during a 35-day incubation. However, increases in methylmercury concentration were linked to bacterial growth and sulfate reduction. A time lag in methylation in the highest treatment correlated with an equivalent lag in bacterial growth

  16. Sewage-sludge-derived carbonaceous materials for catalytic wet hydrogen peroxide oxidation of m-cresol in batch and continuous reactors.

    Science.gov (United States)

    Yu, Yang; Wei, Huangzhao; Yu, Li; Wang, Wei; Zhao, Ying; Gu, Bin; Sun, Chenglin

    2016-01-01

    In this study, four sewage-sludge-derived carbonaceous materials (SWs) were evaluated for their catalytic wet hydrogen peroxide oxidation (CWPO) performance of m-cresol in batch reactor and continuous reactor, respectively. The SWs were produced by carbonization (SW); carbonization with the addition of CaO (CaO-SW); HNO3 pretreatment (HNO3-SW) and steam activation (Activated-SW). The properties of SW catalysts were assessed by thermogravimetric analysis, Brunauer-Emmett-Teller, Fourier Transform Infrared Spectroscopy, X-ray Fluorescence, Scanning electron microscopy, energy dispersive X-ray analysis and zeta potential. The results showed that SW treated by HNO3 (HNO3-SW) had a high conversion of m-cresol in batch reactor and continuous reactor, respectively. Under the conditions of batch reaction (Cm-cresol = 100 mg L(-1), CH2O2 = 15.7 mmol L(-1), initial pH=7.0, 0.5 g L(-1) catalyst, 80°C, 180 min adsorption and 210 min oxidation), the conversion of m-cresol reached 100% and total organic carbon removal was 67.1%. It had a high catalytic activity and stability on the treatment of m-cresol in CWPO for more than 1100 h. Furthermore, a possible reaction mechanism for the oxidation of m-cresol to 2-methyl-p-benzoquinone by CWPO was proposed. PMID:26109374

  17. Kinetics of electrochemical dechlorination of 2-chlorobiphenyl on a palladium-modified nickel foam cathode in a basic medium: From batch to continuous reactor operation

    International Nuclear Information System (INIS)

    A kinetic model for the electrochemical dechlorination of polychlorinated biphenyls (PCBs) will be an important contribution to the design and optimization of a continuous reactor. Initially, the electrocatalytic hydrodechlorination of 2-chlorobiphenyl (2-ClBP) to biphenyl at a palladium-modified nickel foam (Pd/Ni) cathode in a batch reactor was used as a model reaction for a quantitative study of the influences of the operating parameters, including temperature, the initial concentrations of PCBs, current density and the amount of Pd loading, on the apparent reaction rate. The dechlorination was found to follow pseudo first-order kinetics with respect to the 2-ClBP concentration. It was also found that a simple global power law rate equation, with Arrhenius dependency, can be used to describe the correlation between the pseudo first-order reaction rate constants and the reaction conditions. Subsequently, a mathematical model for predicting the performance of reductive dechlorination of 2-ClBP on Pd/Ni electrodes in a continuous stirred tank reactor was constructed, based on the batch-reaction kinetics. The suitability of the model was validated by performing experiments in and out of the range of reaction conditions applied in the batch reactor. The results show that the calculated values are a good fit to the experimental data

  18. Formation of Aerobic Granular Sludge in Sequencing Batch Reactor: Comparison of Different Divalent Metal Ions as Cofactors

    Science.gov (United States)

    Liu, Lin; Gao, Dawen; Zhang, Min

    2010-11-01

    The two sequencing batch reactors (SBRs) were operated to investigate the different effect of Ca2+ and Mg2+ augmentation on aerobic granulation. R1 was augmented with Ca2+ at 40 mg/L, while Mg+ was added to R2 with 40 mg/L. Results indicated that R1 had a faster granulation process, and aerobic granulation reached the steady state after 60 cycles in R1 but 80 cycles in R2. The mean diameter of the mature granules in R1 was 1.6 mm which was consistently larger than that (0.8 mm) in R2, and aerobic granules in R1 also showed a higher physical strength. However, the mature granules in R2 had the higher production yield of polysaccharides and proteins, and aerobic granules in R2 experienced a faster substrate biodegradation. Microbial and genetic characteristics in mature granules were analyzed using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) techniques. The results revealed that Mg2+ addition led to higher microbial diversity in mature granules. In addition, the uncultured bacterium (AB447697) was major specie in R1, and β-proteobacterium was dominant in R2.

  19. Liquefaction studies of low-rank Malaysian coal using high-pressure high-temperature batch-wise reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mohd Azlan Mohd Ishak; Khudzir Ismail; Mohd Fauzi Abdullah; Mohd Omar Abdul Kadir; Abdul Rahman Mohamed; Wan Hasiah Abdullah [University Technology MARA, Perlis (Malaysia). Fuel Combustion Research Laboratory, Faculty of Applied Sciences

    2005-12-01

    Direct liquefaction of low-rank Malaysian coal from the Mukah Balingian (MB) area was successfully carried out in a 1000 ml high-temperature (360-450{sup o}C) high-pressure (4-13 MPa) batch-wise reactor system using tetralin as hydrogen donor solvent. The results indicated that the percent coal conversion obtained were in the range of 31-90%. At optimum conditions of 450{sup o}C and 4 MPa, the oil + gas, asphaltene and preasphaltene of the coal extract were 80%, 7%, and 2%, respectively. It was observed that heat plays an important role in comparison to pressure in contributing to high coal conversion, oil yield, and organic properties of the residues. The high coal conversion and oil yield correlate well with the high content of reactive macerals, i.e., vitrinite and exinite, in the coal. Other parameters that were also investigated include the effect of reaction time (0-120 min) and coal-to-solvent ratio. A high yield of asphaltene and preasphaltene was obtained at the longest reaction time (i.e., 120 min). Coal conversion and oil yield increase with increasing in coal-to-solvent ratio, with the optimal ratio being 1:5.

  20. Simultaneous removal of nutrients from milking parlor wastewater using an AO2 sequencing batch reactor (SBR) system.

    Science.gov (United States)

    Wu, Xiao; Zhu, Jun

    2015-01-01

    The feasibility of using a lab-scale, anaerobic-aerobic-anoxic-aerobic sequencing batch reactor ((AO)2 SBR) to simultaneously remove biological organics, nitrogen and phosphorus from dairy milking parlor wastewater was investigated in this study. Three hydraulic retention times (HRT = 2.1, 2.7, and 3.5 days) and three mixing-to-process time ratios (TM/TP = 0.43, 0.57, and 0.68) were evaluated as two controlling factors using a 3 × 3 experimental design to determine the optimal combination. Results showed that the HRT of 2.7 days with TM/TP = 0.57 was the best to achieve simultaneous nutrients removal for the influent with initial soluble chemical oxygen demand (SCOD) of about 2000 mg L(-1) (only 0.55 mg L(-1) NH4-N, < 0.1 mg L(-1) nitrate, and 0.14 mg L(-1) soluble phosphorus in the effluent). Good correlations between pH and ORP, and ORP and DO, were also obtained with correlation coefficients all higher than or equal to 0.975. These relationships could be used to develop real-time control strategies to optimize the duration of each operating phase in the (AO)2 SBR system to save energy and enhance treatment efficiency. PMID:25723066

  1. Alkaline cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 in a batch reactor. Influence of pH

    International Nuclear Information System (INIS)

    Water containing cyanide was biologically detoxified with the bacterial strain Pseudomonas pseudoalcaligenes CECT5344 in a batch reactor. Volatilization of toxic hydrogen cyanide (HCN) was avoided by using an alkaline medium for the treatment. The operational procedure was optimized to assess cyanide biodegradation at variable pH values and dissolved oxygen concentrations. Using an initial pH of 10 without subsequent adjustment allowed total cyanide to be consumed at a mean rate of approximately 2.81 mg CN- L-1 O.D.-1 h-1; however, these conditions posed a high risk of HCN formation. Cyanide consumption was found to be pH-dependent. Thus, no bacterial growth was observed with a controlled pH of 10; on the other hand, pH 9.5 allowed up to 2.31 mg CN- L-1 O.D.-1 h-1 to be converted. The combination of a high pH and a low dissolved oxygen saturation (10%) minimized the release of HCN. This study contributes new basic knowledge about this biological treatment, which constitutes an effective alternative to available physico-chemical methods for the purification of wastewater containing cyanide or cyano-metal complexes.

  2. Modeling of kinetics of Cr(VI) sorption onto grape stalk waste in a stirred batch reactor

    International Nuclear Information System (INIS)

    Recently, Cr(VI) removal by grape stalks has been postulated to follow two mechanisms, adsorption and reduction to trivalent chromium. Nevertheless, the rate at which both processes take place and the possible simultaneity of both processes has not been investigated. In this work, kinetics of Cr(VI) sorption onto grape stalk waste has been studied. Experiments were carried out at different temperatures but at a constant pH (3 ± 0.1) in a stirred batch reactor. Results showed that three steps take place in the process of Cr(VI) sorption onto grape stalk waste: Cr(VI) sorption, Cr(VI) reduction to Cr(III) and the adsorption of the formed Cr(III). Taking into account the evidences above mentioned, a model has been developed to predict Cr(VI) sorption on grape stalks on the basis of (i) irreversible reduction of Cr(VI) to Cr(III) reaction, whose reaction rate is assumed to be proportional to the Cr(VI) concentration in solution and (ii) adsorption and desorption of Cr(VI) and formed Cr(III) assuming that all the processes follow Langmuir type kinetics. The proposed model fits successfully the kinetic data obtained at different temperatures and describes the kinetics profile of total, hexavalent and trivalent chromium. The proposed model would be helpful for researchers in the field of Cr(VI) biosorption to design and predict the performance of sorption processes.

  3. Landfill leachate treatment using powdered activated carbon augmented sequencing batch reactor (SBR) process: Optimization by response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Shuokr Qarani [School of Civil Engineering, Universiti Sains Malaysia (USM), 14300 Nibong Tebal, Penang (Malaysia); Aziz, Hamidi Abdul, E-mail: cehamidi@eng.usm.my [School of Civil Engineering, Universiti Sains Malaysia (USM), 14300 Nibong Tebal, Penang (Malaysia); Yusoff, Mohd Suffian; Bashir, Mohammed J.K. [School of Civil Engineering, Universiti Sains Malaysia (USM), 14300 Nibong Tebal, Penang (Malaysia)

    2011-05-15

    In this study, landfill leachate was treated by using the sequencing batch reactor (SBR) process. Two types of the SBR, namely non-powdered activated carbon and powdered activated carbon (PAC-SBR) were used. The influence of aeration rate and contact time on SBR and PAC-SBR performances was investigated. Removal efficiencies of chemical oxygen demand (COD), colour, ammoniacal nitrogen (NH{sub 3}-N), total dissolved salts (TDS), and sludge volume index (SVI) were monitored throughout the experiments. Response surface methodology (RSM) was applied for experimental design, analysis and optimization. Based on the results, the PAC-SBR displayed superior performance in term of removal efficiencies when compared to SBR. At the optimum conditions of aeration rate of 1 L/min and contact time of 5.5 h the PAC-SBR achieved 64.1%, 71.2%, 81.4%, and 1.33% removal of COD, colour, NH{sub 3}-N, and TDS, respectively. The SVI value of PAC-SBR was 122.2 mL/g at optimum conditions.

  4. Landfill leachate treatment using powdered activated carbon augmented sequencing batch reactor (SBR) process: optimization by response surface methodology.

    Science.gov (United States)

    Aziz, Shuokr Qarani; Aziz, Hamidi Abdul; Yusoff, Mohd Suffian; Bashir, Mohammed J K

    2011-05-15

    In this study, landfill leachate was treated by using the sequencing batch reactor (SBR) process. Two types of the SBR, namely non-powdered activated carbon and powdered activated carbon (PAC-SBR) were used. The influence of aeration rate and contact time on SBR and PAC-SBR performances was investigated. Removal efficiencies of chemical oxygen demand (COD), colour, ammoniacal nitrogen (NH(3)-N), total dissolved salts (TDS), and sludge volume index (SVI) were monitored throughout the experiments. Response surface methodology (RSM) was applied for experimental design, analysis and optimization. Based on the results, the PAC-SBR displayed superior performance in term of removal efficiencies when compared to SBR. At the optimum conditions of aeration rate of 1L/min and contact time of 5.5h the PAC-SBR achieved 64.1%, 71.2%, 81.4%, and 1.33% removal of COD, colour, NH(3)-N, and TDS, respectively. The SVI value of PAC-SBR was 122.2 mL/g at optimum conditions. PMID:21420786

  5. The effects of Bacillus subtilis on nitrogen recycling from aquaculture solid waste using heterotrophic nitrogen assimilation in sequencing batch reactors.

    Science.gov (United States)

    Lu, Lu; Tan, Hongxin; Luo, Guozhi; Liang, Wenyan

    2012-11-01

    A sequencing batch reactor (SBR) supplied with Bacillus subtilis (treatment group) was employed to treat the sludge from a re-circulating aquaculture system (RAS). The crude protein content of bio-flocs from the treatment group increased from 21.52%±1.5% to 29.65%±13.34%, which was 23.97%±11.62% greater than that of the SBRs without B. subtilis (control group). The removal rate of dissolved inorganic nitrogen (RR(DIN)) for the treatment group was 0.41±0.079 mg L(-1)d(-1), which was 1.17 times greater than that of the control group. The utility rate of total organic nitrogen (UR(TON)) for the treatment group was 1.42±0.33 mg L(-1)d(-1), which was 1.71 times greater than the control. The removal rate of dissolved organic carbon (RR(DOC)) for the treatment group was 138.39±7.77 mg L(-1)d(-1), which was 1.95 times greater than the control. The extra-cellular polymer substance (EPS) was primarily composed of polysaccharides. The flocs volume after 5 min (FV-5 min) reached 22.67%±2.08% at 19 days. PMID:22989644

  6. Landfill leachate treatment using powdered activated carbon augmented sequencing batch reactor (SBR) process: Optimization by response surface methodology

    International Nuclear Information System (INIS)

    In this study, landfill leachate was treated by using the sequencing batch reactor (SBR) process. Two types of the SBR, namely non-powdered activated carbon and powdered activated carbon (PAC-SBR) were used. The influence of aeration rate and contact time on SBR and PAC-SBR performances was investigated. Removal efficiencies of chemical oxygen demand (COD), colour, ammoniacal nitrogen (NH3-N), total dissolved salts (TDS), and sludge volume index (SVI) were monitored throughout the experiments. Response surface methodology (RSM) was applied for experimental design, analysis and optimization. Based on the results, the PAC-SBR displayed superior performance in term of removal efficiencies when compared to SBR. At the optimum conditions of aeration rate of 1 L/min and contact time of 5.5 h the PAC-SBR achieved 64.1%, 71.2%, 81.4%, and 1.33% removal of COD, colour, NH3-N, and TDS, respectively. The SVI value of PAC-SBR was 122.2 mL/g at optimum conditions.

  7. Economic and environmental performance of oil transesterification in supercritical methanol at different reaction conditions: Experimental study with a batch reactor

    International Nuclear Information System (INIS)

    Highlights: • Influence of reaction parameters on FAME yields has been investigated. • The highest yield (93%) was achieved after 15 min at 350 °C and 12 MPa. • Models which predict with high certainty yields at different reaction conditions. • Economic and environmental performance of supercritical transesterification. • The lowest costs and impacts are always achieved at the highest yields. - Abstract: This study aims to investigate the influence of various reaction parameters (temperatures, working pressures and reaction time) on biodiesel yields and environmental and economic performance of rapeseed oil transesterification in supercritical methanol. Experiments were carried out in a laboratory-scale batch reactor. Results were statistically analysed and multiple regression models which describe and predict biodiesel yields with high certainty at different reaction conditions were provided. The highest biodiesel yield (93 wt%) was achieved at 350 °C and 12 MPa after 15 min of reaction. The lowest direct costs and life cycle environmental impacts (in terms of GHG emissions and fossil energy demand) are achieved at the highest yield due to the lowest oil consumption per unit of biodiesel produced. The results of sensitivity analysis showed that even at significantly lower oil feedstock prices this observation stands firm

  8. 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.

  9. Effects of antibiotic resistance genes on the performance and stability of different microbial aggregates in a granular sequencing batch reactor.

    Science.gov (United States)

    Zou, Wenci; Xue, Bin; Zhi, Weijia; Zhao, Tianyu; Yang, Dong; Qiu, Zhigang; Shen, Zhiqiang; Li, Junwen; Zhang, Bin; Wang, Jingfeng

    2016-03-01

    Antibiotic resistance genes (ARGs) have emerged as key factors in wastewater environmental contaminants and continue to pose a challenge for wastewater treatment processes. With the aim of investigating the performance of granular sludge system when treating wastewater containing a considerable amount of ARGs, a lab-scale granular sequencing batch reactor (GSBR) where flocculent and granular sludge coexisted was designed. The results showed that after inoculation of donor strain NH4(+)-N purification efficiency diminished from 94.7% to 32.8% and recovered to 95.2% after 10 days. Meanwhile, RP4 plasmid had varying effects on different forms of microbial aggregates. As the size of aggregates increased, the abundance of RP4 in sludge decreased. The residence time of RP4 in granules with particle size exceeding 0.9 mm (14 days) was far shorter than that in flocculent sludge (26 days). Therefore, our studies conclude that with increasing number of ARGs being detected in wastewater, the use of granular sludge system in wastewater treatment processes will allow the reduction of ARGs transmissions and lessen potential ecological threats. PMID:26590870

  10. Enhanced Biological Phosphorus Removal in Anaerobic/Aerobic Sequencing Batch Reactor Supplied with Glucose as Carbon Source

    Institute of Scientific and Technical Information of China (English)

    LIU Yanan; YU Shui-li; JING Guo-lin; ZHAO Bing-jie; GUO Si-yuan

    2005-01-01

    Phosphorus removal performance in an aerobic/aerobic sequencing batch reactor (SBR) supplied with glucose as carbon source was investigated. It was found that there was no phosphate release concomitant with the storing of poly-β-hydroxyalkanoate (PHA) during the anaerobic phase. Whereas, glycogen was soon built up followed by rapid consumption, at the same time, glucose was depleted rapidly. Based on the analysis of different fractions of phosphorus in activated sludge, the relative ratio of organically bound phosphorus in sludge changed at the end of anaerobic and aerobic phases. The ratios were 45.3% and51.8% respectively. This showed that the polyphosphate broke down during the anaerobic phase to supply part of energy for PHA synthesis. The reason why there was no phosphate release might be the biosorption effect of extracellular exopolymers (EPS). It was also proved by the analysis of EPS with scanning electron microscopy (SEM)combined with energy dispersive spectrometry (EDS). The phosphorus weight percentage of EPS at the end of anaerobic phase was 9.22%.

  11. Alkaline cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 in a batch reactor. Influence of pH

    Energy Technology Data Exchange (ETDEWEB)

    Huertas, M.J., E-mail: mjhuertas@us.es [Instituto de Bioquimica Vegetal y Fotosintesis, CSIC-Universidad de Sevilla Avda Americo Vespucio, 49, 41092 Sevilla (Spain); Saez, L.P.; Roldan, M.D.; Luque-Almagro, V.M.; Martinez-Luque, M. [Departamento de Bioquimica y Biologia Molecular, Edificio Severo Ochoa, 1a Planta, Campus de Rabanales, Universidad de Cordoba, 14071 Cordoba (Spain); Blasco, R. [Departamento de Bioquimica y Biologia Molecular y Genetica, Facultad de Veterinaria, Universidad de Extremadura, 11071 Caceres (Spain); Castillo, F.; Moreno-Vivian, C. [Departamento de Bioquimica y Biologia Molecular, Edificio Severo Ochoa, 1a Planta, Campus de Rabanales, Universidad de Cordoba, 14071 Cordoba (Spain); Garcia-Garcia, I. [Departamento de Ingenieria Quimica, Edificio Marie Curie, Campus de Rabanales, Universidad de Cordoba, 14071 Cordoba (Spain)

    2010-07-15

    Water containing cyanide was biologically detoxified with the bacterial strain Pseudomonas pseudoalcaligenes CECT5344 in a batch reactor. Volatilization of toxic hydrogen cyanide (HCN) was avoided by using an alkaline medium for the treatment. The operational procedure was optimized to assess cyanide biodegradation at variable pH values and dissolved oxygen concentrations. Using an initial pH of 10 without subsequent adjustment allowed total cyanide to be consumed at a mean rate of approximately 2.81 mg CN{sup -} L{sup -1} O.D.{sup -1} h{sup -1}; however, these conditions posed a high risk of HCN formation. Cyanide consumption was found to be pH-dependent. Thus, no bacterial growth was observed with a controlled pH of 10; on the other hand, pH 9.5 allowed up to 2.31 mg CN{sup -} L{sup -1} O.D.{sup -1} h{sup -1} to be converted. The combination of a high pH and a low dissolved oxygen saturation (10%) minimized the release of HCN. This study contributes new basic knowledge about this biological treatment, which constitutes an effective alternative to available physico-chemical methods for the purification of wastewater containing cyanide or cyano-metal complexes.

  12. Performance comparison of biofilm and suspended sludge from a sequencing batch biofilm reactor treating mariculture wastewater under oxytetracycline stress.

    Science.gov (United States)

    Zheng, Dong; Gao, Mengchun; Wang, Zhe; She, Zonglian; Jin, Chunji; Chang, Qingbo

    2016-09-01

    The performance, extracellular polymeric substances (EPS) and microbial community of a sequencing batch biofilm reactor (SBBR) were investigated in treating mariculture wastewater under oxytetracycline stress. The chemical oxygen demand and [Formula: see text]-N removal efficiencies of the SBBR decreased with the increase of oxytetracycline concentration, and no obvious [Formula: see text]-N and [Formula: see text]-N accumulation in the effluent appeared at less than 10 mg L(-1) oxytetracycline. The specific oxygen utilization rate of the suspended sludge was more than that of the biofilm at different oxytetracycline concentrations. The specific ammonium oxidation rate (SAOR) of the biofilm was more easily affected by oxytetracycline than that of the suspended sludge, whereas the effect of oxytetracycline on the specific nitrite oxidation rate (SNOR) of the biofilm was less than that of the suspended sludge. The specific nitrate reduction rate of both the biofilm and suspended sludge was higher than the sum of the SAOR and SNOR at different oxytetracycline concentrations. The protein and polysaccharide contents in the EPS of the biofilm and suspended sludge increased with the increase of oxytetracycline concentration. The appearance of oxytetracycline in the influent could affect the chemical composition of the loosely bound EPS and tightly bound EPS. The amino, carboxyl and hydroxyl groups might be involved with interaction between EPS and oxytetracycline. The denaturing gradient gel electrophoresis profiles indicated that the variation of oxytetracycline concentration in the influent could affect the microbial communities of both the biofilm and suspended sludge. PMID:26854088

  13. Advanced nitrogen removal via nitrite using stored polymers in a modified sequencing batch reactor treating landfill leachate.

    Science.gov (United States)

    Miao, Lei; Wang, Shuying; Li, Baikun; Cao, Tianhao; Xue, Tonglai; Peng, Yongzhen

    2015-09-01

    A modified sequencing batch reactor (SBR) operated at the anaerobic-aerobic-anoxic mode was developed in this study to fully utilize the organics in landfill leachate (ammonia concentration of 1000 ± 50 mg N/L and COD/total nitrogen (TN) ratio of 1-4). The unique feature of modified SBR process was the addition of an anaerobic stage after feeding stage, so that microorganisms could store the organics during anaerobic stage and supply the carbon source for endogenous denitritation after aeration stage. The 70-day operational tests showed the effluent TN was below 10 mg N/L at C/N ratio of 4. The intracellular stored polymers were analyzed and the microorganisms were capable of storing the carbon source as polyhydroxybutyrate (PHB) and glycogen in anaerobic stage, which were the electron donors for endogenous denitritation. Fluorescence in situ hybridization (FISH) analysis showed that glycogen accumulating organisms (GAOs) account for 39.8% of microorganisms in SBR, and carried out advanced nitrogen removal. PMID:26056776

  14. Effect of inorganic carbon on the completely autotrophic nitrogen removal over nitrite (CANON) process in a sequencing batch biofilm reactor.

    Science.gov (United States)

    Chen, You-Peng; Li, Shan; Fang, Fang; Guo, Jin-Song; Zhang, Qiang; Gao, Xu

    2012-12-01

    Ammonia-oxidizing bacteria (AOB) and anaerobic ammonia-oxidizing bacteria (AnAOB) are autotrophic microorganisms. Inorganic carbon (IC) is their main carbon source. The effects of IC limitation on AOB and AnAOB in the completely autotrophic nitrogen removal over nitrite (CANON) process in a sequencing batch biofilm reactor (SBBR) were examined. The optimal IC concentration in the influent was investigated. The start-up time of the CANON process from the activated sludge in the SBBR was 80 d under controlled free ammonia (FA) conditions and sufficient IC source. The AOB and AnAOB activities were limited by an IC concentration of 50 mg-C-L(-1) in the influent, whilst the nitrogen loading rate (NLR) was 200 mg-N x L(-1) x d(-1). The experiment on recovering the influent IC showed that AOB and AnAOB activities were affected by the IC limitation, and not by the pH or FA, at 200mg-N x L(-1) x d(-1) NLR and 50mg-C x L(-1) IC in the CANON process. The activities were recovered by increasing the IC concentration in the influent. From an economic point of view, the optimal IC concentration in the influent was 250mg-C x L(-1) at 200mg-N x L(-1) x d(-1) NLR in this CANON system. PMID:23437661

  15. Characteristics of pellets with immobilized activated sludge and its performance in increasing nitrification in sequencing batch reactors at low temperatures.

    Science.gov (United States)

    Dong, Wenjie; Lu, Guang; Yan, Li; Zhang, Zhenjia; Zhang, Yalei

    2016-04-01

    Immobilized pellets obtained by means of entrapping activated sludge in waterborne polyurethane were successfully adapted in ammonium (NH4(+)-N) synthetic wastewater. Its physicochemical characteristics were determined using scanning electron microscope, pyrosequencing, and microelectrodes, and its influence on the nitrification process in sequencing batch reactors (SBRs) at low temperatures was evaluated. A large number of rod-shaped bacteria were observed on the surface of the immobilized pellet, in which Rudaea spp. (Xanthomonadaceae family) was an important bacterial component (23.44% of the total bacteria). The oxygen uptake rate of immobilized pellets reached 240.83±15.59mgO2/(L·hr), and the oxygen was primarily consumed by the bacteria on the pellet surfaces (0-600μm). The dosing of the pellets (30mL/L) into an SBR significantly improved the nitrification efficiency at low temperatures of 7-11°C, achieving an average NH4(+)-N removal of 84.09%, which is higher than the removal of 67.46% observed for the control group. PMID:27090712

  16. Powdered ZELIAC augmented sequencing batch reactors (SBR) process for co-treatment of landfill leachate and domestic wastewater.

    Science.gov (United States)

    Mojiri, Amin; Aziz, Hamidi Abdul; Zaman, Nastaein Q; Aziz, Shuokr Qarani; Zahed, Mohammad Ali

    2014-06-15

    Sequencing batch reactor (SBR) is one of the various methods of biological treatments used for treating wastewater and landfill leachate. This study investigated the treatment of landfill leachate and domestic wastewater by adding a new adsorbent (powdered ZELIAC; PZ) to the SBR technique. ZELIAC consists of zeolite, activated carbon, lime stone, rice husk ash, and Portland cement. The response surface methodology and central composite design were used to elucidate the nature of the response surface in the experimental design and describe the optimum conditions of the independent variables, including aeration rate (L/min), contact time (h), and ratio of leachate to wastewater mixture (%; v/v), as well as their responses (dependent variables). Appropriate conditions of operating variables were also optimized to predict the best value of responses. To perform an adequate analysis of the aerobic process, four dependent parameters, namely, chemical oxygen demand (COD), color, ammonia-nitrogen (NH3-N), and phenols, were measured as responses. The results indicated that the PZ-SBR showed higher performance in removing certain pollutants compared with SBR. Given the optimal conditions of aeration rate (1.74 L/min), leachate to wastewater ratio (20%), and contact time (10.31 h) for the PZ-SBR, the removal efficiencies for color, NH3-N, COD, and phenols were 84.11%, 99.01%, 72.84%, and 61.32%, respectively. PMID:24662109

  17. 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

  18. Mainstream partial nitritation and anammox in a 200,000 m(3)/day activated sludge process in Singapore: scale-down by using laboratory fed-batch reactor.

    Science.gov (United States)

    Yeshi, Cao; Hong, Kwok Bee; van Loosdrecht, Mark C M; Daigger, Glen T; Yi, Png Hui; Wah, Yuen Long; Chye, Chua Seng; Ghani, Yahya Abd

    2016-01-01

    A laboratory fed-batch reactor has been used to study under controlled conditions the performance of partial nitritation/anammox for the 200,000 m(3)/day step-feed activated sludge process at the Changi Water Reclamation Plant, Singapore. The similarity of the concentrations of NH4, NO2, NO3, PO4, suspended chemical oxygen demand (sCOD), pH, and alkalinity (ALK) between the on-site process and laboratory reactor illustrates that the laboratory fed-batch reactor can be used to simulate the site performance. The performance of the reactor fed by primary effluent illustrated the existence of anammox and heterotrophic denitrification and apparent excessive biological phosphorus removal as observed from the site. The performance of the reactor fed by final effluent proved the presence of anammox process on site. Both the laboratory reactor and on-site process showed that higher influent 5-day biochemical oxygen demand/total nitrogen (BOD5/TN) (COD/TN) ratio increases the nitrogen removal efficiency of the process. PMID:27386982

  19. Gas-cooled fast breeder reactor. Quarterly progress report, February 1-April 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    Information is presented concerning the reactor vessel; reactivity control mechanisms and instrumentation; reactor internals; primary coolant circuits;core auxiliary cooling system; reactor core; systems engineering; and reactor safety and reliability;

  20. Evaluation of a sequencing batch reactor sewage treatment rig for investigating the fate of radioactively labelled pharmaceuticals:case study of propranolol

    OpenAIRE

    Popple, T.; WILLIAMS, J.B.; May, E; Mills, Graham; Oliver, R.

    2016-01-01

    Pharmaceuticals are frequently detected in the aquatic environment, and have potentially damaging effects. Effluents from sewage treatment plants (STPs) are major sources of these substances. The use of sequencing batch reactor (SBR) STPs, involving cycling between aerobic and anoxic conditions to promote nitrification and denitrification, is increasing but these have yet to be understood in terms of removal of pharmaceutical residues. This study reports on the development of a laboratory rig...

  1. Time programmed feed of semi-batch reactors with non-linear radical copolymerizations: an experimental study of the system styrene + divinylbenzene using SEC/MALLS

    OpenAIRE

    Gonçalves, Miguel; Dias, Rolando; Costa, Mário Rui

    2007-01-01

    The radical crosslinking copolymerization of mono and divinyl monomers was experimentally studied with a 2.5 dm3 semi-batch reactor using styrene + divinylbenzene as a model system. The analysis of products was carried out by SEC with a MALLS detector. The influence of the feed policy of divinylbenzene on the time evolution of the copolymer molecular weights and z-average mean square radius of gyration was assessed. A detailed kinetic model, in the absence of intramolecular reactions but taki...

  2. Response of aerobic granular sludge to the long-term presence to nanosilver in sequencing batch reactors: Reactor performance, sludge property, microbial activity and community

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Xiangchun, E-mail: xchquan@bnu.edu.cn; Cen, Yan; Lu, Fang; Gu, Lingyun; Ma, Jingyun

    2015-02-15

    The increasing use of silver nanoparticles (Ag NPs) raises concerns about their potential toxic effects on the environment. Granular shape sludge is a special type of microbial aggregate. The response of aerobic granular sludge (AGS) to the long-term presence of Ag NPs has not been well studied. In this study, AGS was exposed to 5 and 50 mg/L Ag NPs in sequence batch reactors (SBRs) for 69 days, and its response was evaluated based on the sludge properties, microbial activity and community, and reactor performance. The results showed that Ag NPs caused inhibition to microbial activities of AGS from Day 35. At the end of 69 days of Ag NPs exposure, the microbial activity of AGS was significantly inhibited in terms of inhibitions of the ammonia oxidizing rate (33.0%), respiration rate (17.7% and 45.6%) and denitrification rate (6.8%), as well as decreases in the ammonia mono-oxygenase and nitrate reductase activities. During the long-term exposure, the AGS maintained its granular shape and large granule size (approximately 900 μm); the microbial community of AGS slightly changed, but the dominant microbial population remained. Overall, the AGS tolerated the toxicity of Ag NPs well, but a long-term exposure may produce chronic toxicity to the AGS, which is concerning. - Highlights: • AGS demonstrated a good tolerance to the long-term presence of Ag NPs. • Ag NPs did not produce acute toxicity but cause chronic toxicity to AGS. • AGS maintained granular shape, granule size and good settling ability. • The microbial community of AGS slightly changed after long-term Ag NPs exposure.

  3. Response of aerobic granular sludge to the long-term presence to nanosilver in sequencing batch reactors: Reactor performance, sludge property, microbial activity and community

    International Nuclear Information System (INIS)

    The increasing use of silver nanoparticles (Ag NPs) raises concerns about their potential toxic effects on the environment. Granular shape sludge is a special type of microbial aggregate. The response of aerobic granular sludge (AGS) to the long-term presence of Ag NPs has not been well studied. In this study, AGS was exposed to 5 and 50 mg/L Ag NPs in sequence batch reactors (SBRs) for 69 days, and its response was evaluated based on the sludge properties, microbial activity and community, and reactor performance. The results showed that Ag NPs caused inhibition to microbial activities of AGS from Day 35. At the end of 69 days of Ag NPs exposure, the microbial activity of AGS was significantly inhibited in terms of inhibitions of the ammonia oxidizing rate (33.0%), respiration rate (17.7% and 45.6%) and denitrification rate (6.8%), as well as decreases in the ammonia mono-oxygenase and nitrate reductase activities. During the long-term exposure, the AGS maintained its granular shape and large granule size (approximately 900 μm); the microbial community of AGS slightly changed, but the dominant microbial population remained. Overall, the AGS tolerated the toxicity of Ag NPs well, but a long-term exposure may produce chronic toxicity to the AGS, which is concerning. - Highlights: • AGS demonstrated a good tolerance to the long-term presence of Ag NPs. • Ag NPs did not produce acute toxicity but cause chronic toxicity to AGS. • AGS maintained granular shape, granule size and good settling ability. • The microbial community of AGS slightly changed after long-term Ag NPs exposure

  4. Contamination level of four priority phthalates in North Indian wastewater treatment plants and their fate in sequencing batch reactor systems.

    Science.gov (United States)

    Gani, Khalid Muzamil; Rajpal, Ankur; Kazmi, Absar Ahmad

    2016-03-16

    The contamination level of four phthalates in untreated and treated wastewater of fifteen wastewater treatment plants (WWTPs) and their fate in a full scale sequencing batch reactor (SBR) based WWTP was evaluated in this study. The four phthalates were diethyl phthalate (DEP), dibutyl phthalate (DBP), benzylbutyl phthalate (BBP) and diethylhexyl phthalate (DEHP). All compounds were present in untreated wastewater with DEHP being present in the highest mean concentration of 28.4 ± 5.3 μg L(-1). The concentration was in the range of 7.3 μg L(-1) (BBP) to 28.4 μg L(-1) (DEHP) in untreated wastewater and 1.3 μg L(-1) (DBP) to 2.6 μg L(-1) (DEHP) in treated wastewater. The nutrient removal process and advance tertiary treatment based WWTPs showed the highest phthalate removal efficiencies of 87% and 93%, respectively. The correlation between phthalate removal and conventional performance of WWTPs was positive. Fate analysis of these phthalates in a SBR based WWTP showed that total removal of the sum of phthalates in a primary settling tank and SBR was 84% out of which 55% is removed by biodegradation and 29% was removed by sorption to primary and secondary sludge. The percentage removal of four phthalates in primary settling tanks was 18%. Comparison of the diluted effluent DEHP concentration with its environmental quality standards showed that the dilution in an effluent receiving water body can reduce the DEHP emissions to acceptable values. PMID:26923228

  5. Treatment of a simulated textile wastewater in a sequencing batch reactor (SBR) with addition of a low-cost adsorbent

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Sílvia C.R., E-mail: scrs@fe.up.pt; Boaventura, Rui A.R.

    2015-06-30

    Highlights: • Treating textile dyeing effluents by SBR coupled with waste sludge adsorption. • Metal hydroxide sludge: a good adsorbent for a direct textile dye. • Good adsorption capacities were found with the low-cost adsorbent. • Adsorbent performance considerably reduced by auxiliary products. • Color removal complies with discharge limits. - Abstract: Color removal from textile wastewaters, at a low-cost and consistent technology, is even today a challenge. Simultaneous biological treatment and adsorption is a known alternative to the treatment of wastewaters containing biodegradable and non-biodegradable contaminants. The present work aims at evaluating the treatability of a simulated textile wastewater by simultaneously combining biological treatment and adsorption in a SBR (sequencing batch reactor), but using a low-cost adsorbent, instead of a commercial one. The selected adsorbent was a metal hydroxide sludge (WS) from an electroplating industry. Direct Blue 85 dye (DB) was used in the preparation of the synthetic wastewater. Firstly, adsorption kinetics and equilibrium were studied, in respect to many factors (temperature, pH, WS dosage and presence of salts and dyeing auxiliary chemicals in the aqueous media). At 25 °C and pH 4, 7 and 10, maximum DB adsorption capacities in aqueous solution were 600, 339 and 98.7 mg/g, respectively. These values are quite considerable, compared to other reported in literature, but proved to be significantly reduced by the presence of dyeing auxiliary chemicals in the wastewater. The simulated textile wastewater treatment in SBR led to BOD{sub 5} removals of 53–79%, but color removal was rather limited (10–18%). The performance was significantly enhanced by the addition of WS, with BOD{sub 5} removals above 91% and average color removals of 60–69%.

  6. Process evaluation of an alternating aerobic-anoxic process applied in a sequencing batch reactor for nitrogen removal

    Institute of Scientific and Technical Information of China (English)

    ZENG Wei; PENG Yongzhen; WANG Shuying

    2007-01-01

    In order to improve the nitrogen removal efficiency and save operational cost,the feasibility of the alternating aerobic-anoxic process(AAA process)applied in a sequencing batch reactor(SBR)system for nitrogen removal was investigated.Under sufficient influent alkalinity,the AAA process did not have an advantage over one aerobicanoxic(OAA)cycle on treatment efficiency because microorganisms had an adaptive stage at the alternating aerobic-anoxic transition,which would prolong the total cycling time.On the contrary,the AAA process made the system control more complicated.Under deficient influent alkalinity,when compared to OAA,the AAA process improved treatment efficiency and effluent quality with NH4+-N in the effluent below the detection limit.In the nitrification.the average stoichiometric ratio between alkalinity consumption and ammonia oxidation is calculated to be 7.07 mg CaCO3/mg NH4+-N.In the denitrification,the aver age stoichiometric ratio between alkalinity production and NO3- -N reduction is about 3.57 mg CaCO3/mg NO3- -N.As a result,half of the alkalinity previously consumed during the aerobic nitrification was recovered during the subsequent anoxic denitrification period.That was why the higher treatment efficiency in the AAA process was achieved without the supplement of bicarbonate alkalinity.If the lack of alkalinity in the influent was less than 1/3 of that needed.there is no need for external alkalinity addition and treatment efficiency was the same as that under sufficient influent alkalinity.Eyen if the lack of alkalinity in the influent was more than 1/3 of that needed.the AAA process was an optimal strategy because it reduced the external alkalinity addition and saved on operational cost.

  7. Sequencing Batch Reactor (SBR) for the removal of Hg2+ and Cd2+ from synthetic petrochemical factory wastewater

    International Nuclear Information System (INIS)

    Highlights: → We assessed SBR performances to treat synthetic wastewater containing Hg2+ and Cd2+. → SBR was able to remove 76-90% of Hg2+ and 96-98% of Cd2+. → COD removal efficiency and MLVSS was affected by Hg2+ and Cd2+ concentrations. → Removal was not only biological process but also by biosorption process of sludge. - Abstract: Petrochemical factories which manufacture vinyl chloride monomer and poly vinyl chloride (PVC) are among the largest industries which produce wastewater contains mercury and cadmium. The objective of this research is to evaluate the performance of a lab-scale Sequencing Batch Reactor (SBR) to treat a synthetic petrochemical wastewater containing mercury and cadmium. After acclimatization of the system which lasted 60 days, the SBR was introduced to mercury and cadmium in low concentrations which then was increased gradually to 9.03 ± 0.02 mg/L Hg and 15.52 ± 0.02 mg/L Cd until day 110. The SBR performance was assessed by measuring Chemical Oxygen Demand, Total and Volatile Suspended Solids as well as Sludge Volume Index. At maximum concentrations of the heavy metals, the SBR was able to remove 76-90% of Hg2+ and 96-98% of Cd2+. The COD removal efficiency and MLVSS (microorganism population) in the SBR was affected by mercury and cadmium concentrations in influent. Different species of microorganisms such as Rhodospirilium-like bacteria, Gomphonema-like algae, and sulfate reducing-like bacteria were identified in the system. While COD removal efficiency and MLVSS concentration declined during addition of heavy metals, the appreciable performance of SBR in removal of Hg2+ and Cd2+ implies that the removal in SBR was not only a biological process, but also by the biosorption process of the sludge.

  8. Dry anaerobic digestion of high solids content dairy manure at high organic loading rates in psychrophilic sequence batch reactor.

    Science.gov (United States)

    Massé, Daniel I; Saady, Noori M Cata

    2015-05-01

    Cow manure with bedding is renewable organic biomass available around the year on dairy farms. Developing efficient and cost-effective psychrophilic dry anaerobic digestion (PDAD) processes could contribute to solving farm-related environmental, energy, and manure management problems in cold-climate regions. This study was to increase the organic loading rate (OLR), fed to a novel psychrophilic (20 °C) dry anaerobic digestion of 27% total solid dairy manure (cow feces and wheat straw) in sequence batch reactor (PDAD-SBR), by 133 to 160%. The PDAD-SBR process operated at treatment cycle length of 21 days and OLR of 7.0 and 8.0 g total chemical oxygen demand (TCOD) kg(-1) inoculum day(-1) (5.2 ± 0.1 and 5.8 ± 0.0 g volatile solids (VS) kg(-1) inoculum day(-1)) for four successive cycles (84 days) produced average specific methane yields (SMYs) of 147.1 ± 17.2 and 143.2 ± 11.7 normalized liters (NL) CH4 kg(-1) VS fed, respectively. PDAD of cow feces and wheat straw is possible with VS-based inoculum-to-substrate ratio of 1.45 at OLR of 8.0 g TCOD kg(-1) inoculum day(-1). Hydrolysis was the limiting step reaction. The VS removal averaged around 57.4 ± 0.5 and 60.5 ± 5.7% at OLR 7.0 and 8.0 g TCOD kg(-1) inoculum day(-1), respectively. PMID:25773978

  9. Treatment of arsenic contaminated water in a batch reactor by using Ralstonia eutropha MTCC 2487 and granular activated carbon

    International Nuclear Information System (INIS)

    This paper presents the observations on the bio-removal of arsenic from contaminated water by using Ralstonia eutropha MTCC 2487 and activated carbon in a batch reactor. The effects of agitation time, pH, type of granular activated carbon (GAC) and initial arsenic concentration (Aso) on the % removal of arsenic have been discussed. Under the experimental conditions, optimum removal was obtained at the pH of 6-7 with agitation time of 100 h. The % removal of As(T) increased initially with the increase in Aso and after attaining the maximum removal (∼86%) at the Aso value of around 15 ppm, it started to decrease. Simultaneous adsorption bioaccumulation (SABA) was observed, when fresh GAC was used as supporting media for bacterial immobilization. In case of SABA, the % removal of As(III) was almost similar (only ∼1% more) to the additive values of individual removal of As(III) obtained by only adsorption and only bio-adsorption. However, for As(V) the % removal was less (∼8%) than the additive value of the individual % removals obtained by only adsorption and bio-adsorption. Percentage removal of Fe, Mn, Cu and Zn were 65.17%, 72.76%, 98.6% and 99.31%, respectively. Maximum regeneration (∼99.4%) of the used bio-adsorbent was achieved by the treatment with 5NH2SO4 followed by 1N NaOH and 30% H2O2 in HNO3. The fitness of the isotherms to predict the specific uptake for bio-adsorption/accumulation process has been found to decrease in the following order: Temkin isotherm > Langmuir isotherm > Freundlich isotherm. For the adsorption process with fresh GAC the corresponding order is Freundlich isotherm > Langmuir isotherm > Temkin isotherm for As(V) and As(T). However, for As(III) it was Langmuir > Temkin > Freundlich

  10. Individual and combined effects of organic, toxic, and hydraulic shocks on sequencing batch reactor in treating petroleum refinery wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Mizzouri, Nashwan Sh., E-mail: nashwan_mizzouri@yahoo.com [Department of Civil Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Department of Civil Engineering, University of Duhok, Kurdistan (Iraq); Shaaban, Md Ghazaly [Department of Civil Engineering, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia)

    2013-04-15

    Highlights: ► This research focuses on the combined impact of shock loads on the PRWW treatment. ► System failure resulted when combined shock of organic and hydraulic was applied. ► Recovery was achieved by replacing glucose with PRWW and OLR was decreased to half. ► Worst COD removals were 68.9, and 57.8% for organic, and combined shocks. -- Abstract: This study analyzes the effects of toxic, hydraulic, and organic shocks on the performance of a lab-scale sequencing batch reactor (SBR) with a capacity of 5 L. Petroleum refinery wastewater (PRWW) was treated with an organic loading rate (OLR) of approximately 0.3 kg chemical oxygen demand (COD)/kg MLSS d at 12.8 h hydraulic retention time (HRT). A considerable variation in the COD was observed for organic, toxic, hydraulic, and combined shocks, and the worst values observed were 68.9, 77.1, 70.2, and 57.8%, respectively. Improved control of toxic shock loads of 10 and 20 mg/L of chromium (VI) was identified. The system was adversely affected by the organic shock when a shock load thrice the normal value was used, and this behavior was repeated when the hydraulic shock was 4.8 h HRT. The empirical recovery period was greater than the theoretical period because of the inhibitory effects of phenols, sulfides, high oil, and grease in the PRWW. The system recovery rates from the shocks were in the following order: toxic, organic, hydraulic, and combined shocks. System failure occurred when the combined shocks of organic and hydraulic were applied. The system was resumed by replacing the PRWW with glucose, and the OLR was reduced to half its initial value.

  11. Treatment of a simulated textile wastewater in a sequencing batch reactor (SBR) with addition of a low-cost adsorbent

    International Nuclear Information System (INIS)

    Highlights: • Treating textile dyeing effluents by SBR coupled with waste sludge adsorption. • Metal hydroxide sludge: a good adsorbent for a direct textile dye. • Good adsorption capacities were found with the low-cost adsorbent. • Adsorbent performance considerably reduced by auxiliary products. • Color removal complies with discharge limits. - Abstract: Color removal from textile wastewaters, at a low-cost and consistent technology, is even today a challenge. Simultaneous biological treatment and adsorption is a known alternative to the treatment of wastewaters containing biodegradable and non-biodegradable contaminants. The present work aims at evaluating the treatability of a simulated textile wastewater by simultaneously combining biological treatment and adsorption in a SBR (sequencing batch reactor), but using a low-cost adsorbent, instead of a commercial one. The selected adsorbent was a metal hydroxide sludge (WS) from an electroplating industry. Direct Blue 85 dye (DB) was used in the preparation of the synthetic wastewater. Firstly, adsorption kinetics and equilibrium were studied, in respect to many factors (temperature, pH, WS dosage and presence of salts and dyeing auxiliary chemicals in the aqueous media). At 25 °C and pH 4, 7 and 10, maximum DB adsorption capacities in aqueous solution were 600, 339 and 98.7 mg/g, respectively. These values are quite considerable, compared to other reported in literature, but proved to be significantly reduced by the presence of dyeing auxiliary chemicals in the wastewater. The simulated textile wastewater treatment in SBR led to BOD5 removals of 53–79%, but color removal was rather limited (10–18%). The performance was significantly enhanced by the addition of WS, with BOD5 removals above 91% and average color removals of 60–69%

  12. Individual and combined effects of organic, toxic, and hydraulic shocks on sequencing batch reactor in treating petroleum refinery wastewater

    International Nuclear Information System (INIS)

    Highlights: ► This research focuses on the combined impact of shock loads on the PRWW treatment. ► System failure resulted when combined shock of organic and hydraulic was applied. ► Recovery was achieved by replacing glucose with PRWW and OLR was decreased to half. ► Worst COD removals were 68.9, and 57.8% for organic, and combined shocks. -- Abstract: This study analyzes the effects of toxic, hydraulic, and organic shocks on the performance of a lab-scale sequencing batch reactor (SBR) with a capacity of 5 L. Petroleum refinery wastewater (PRWW) was treated with an organic loading rate (OLR) of approximately 0.3 kg chemical oxygen demand (COD)/kg MLSS d at 12.8 h hydraulic retention time (HRT). A considerable variation in the COD was observed for organic, toxic, hydraulic, and combined shocks, and the worst values observed were 68.9, 77.1, 70.2, and 57.8%, respectively. Improved control of toxic shock loads of 10 and 20 mg/L of chromium (VI) was identified. The system was adversely affected by the organic shock when a shock load thrice the normal value was used, and this behavior was repeated when the hydraulic shock was 4.8 h HRT. The empirical recovery period was greater than the theoretical period because of the inhibitory effects of phenols, sulfides, high oil, and grease in the PRWW. The system recovery rates from the shocks were in the following order: toxic, organic, hydraulic, and combined shocks. System failure occurred when the combined shocks of organic and hydraulic were applied. The system was resumed by replacing the PRWW with glucose, and the OLR was reduced to half its initial value

  13. Cold-walled UHV/CVD batch reactor for the growth of Si1_x/Gex layers

    DEFF Research Database (Denmark)

    Thomsen, Erik Vilain; Christensen, Carsten; Andersen, C.R.;

    1997-01-01

    A novel cold-walled, lamp-heated, ultrahigh vacuum chemical vapor deposition (UHV/CVD) batch system for the growth of SiGe layers is presented. This system combines the batch capability of the standard UHV/CVD furnace with the temperature processing available in rapid thermal processing (Rm...

  14. Effects of the addition of an organic polymer on the hydrolysis of sodium tetrahydroborate in batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, M.J.F.; Pinto, A.M.F.R. [Centro de Estudos de Fenomenos de Transporte, Departamento de Engenharia Quimica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto (Portugal); Fernandes, V.R.; Rangel, C.M. [Laboratorio Nacional de Energia e Geologia - LNEG, Fuel Cells and Hydrogen Unit, Estrada do Paco do Lumiar 22, 1649-038 Lisboa (Portugal); Gales, L. [Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto and Instituto de Ciencias Biomedicas Abel Salazar, Largo Prof. Abel Salazar 2, 4099-003 Porto (Portugal)

    2010-10-15

    An experimental study is presented both on the generation and storage of molecular hydrogen (H{sub 2}) by small additions of an organic polymer -carboxymethyl cellulose (CMC) - to sodium borohydride (NaBH{sub 4}) through the alkaline hydrolysis, in the presence of a powdered nickel-ruthenium based catalyst reused from 274 to 282 times. The experiments were performed at 45 C in two batch reactors with internal volumes of 0.229 L and 0.369 L, made of stainless-steel with bottom conical shape, positioned vertically. The results showed that working at moderate pressures, up to 2.7 MPa, increases slightly the H{sub 2} dissolution in the liquid phase, enhanced by the changing of the polarity of the remained solution inside the reactor: a value of 0.182 for dimensionless H{sub 2} solubility in the liquid phase with 0.25 wt% CMC was found, at 45 C, based on Henry's law. As a consequence, sodium tetrahydroxoborate, NaB(OH){sub 4} by-product was produced in the presence of CMC additive, showing the absence of crystalline water in its crystal structure (NaB(OH){sub 4} presents structural water, with boron atoms linked to four hydroxyl groups). This new finding never reported to form at < 50 C, has a positive impact in recyclability costs of NaBO{sub 2} back to NaBH{sub 4} due to the elimination of two energy consuming steps in the metaborate dehydration kinetics. In fact our system of compressed hydrogen, shows that both H{sub 2} generation rates and yields and hydrogen storage capacities can be augmented, the latter to reach {approx} 6 wt%, by adding small amounts of an organic polymer (CMC) to the classic NaBH{sub 4} hydrolysis, performed with stoichiometric amount of water. The eventual success of this new route will depend upon developing a advantageous method of converting borates into tetrahydroborate and also finding materials (chemicals) which enhance the solubility of H{sub 2

  15. Enforcement actions: Significant actions resolved reactor licensees. Quarterly progress report, October--December 1994, Volume 13, No. 4, Part 1

    International Nuclear Information System (INIS)

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1994) and includes copies of letters Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  16. Enforcement actions: Significant actions resolved, reactor licensees. Quarterly progress report, July--September 1994; Volume 13, Number 3, Part 1

    International Nuclear Information System (INIS)

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (July--September 1994) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  17. Enforcement actions: Significant actions resolved reactor licensees. Volume 14, No. 2, Part 2, Quarterly progress report, April--June 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication.

  18. Enforcement actions: Significant actions resolved reactor licensees. Quarterly progress report, October--December 1994, Volume 13, No. 4, Part 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (October--December 1994) and includes copies of letters Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication.

  19. Enforcement actions: Significant actions resolved reactor licensees. Volume 13, No. 1, Part 1: Quarterly progress report, January--March 1994

    International Nuclear Information System (INIS)

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1994) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to these described in this publication

  20. Enforcement actions: Significant actions resolved reactor licensees. Volume 14, No. 2, Part 2, Quarterly progress report, April--June 1995

    International Nuclear Information System (INIS)

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (April--June 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  1. Enforcement actions: Significant actions resolved. Reactor licensees: Volume 14, No. 1, Part 1, Quarterly progress report January--March 1995

    International Nuclear Information System (INIS)

    This compilation summarizes significant enforcement actions that have been resolved during one quarterly period (January--March 1995) and includes copies of letters, Notices, and Orders sent by the Nuclear Regulatory Commission to reactor licensees with respect to these enforcement actions. It is anticipated that the information in this publication will be widely disseminated to managers and employees engaged in activities licensed by the NRC, so that actions can be taken to improve safety by avoiding future violations similar to those described in this publication

  2. Microbial succession within an anaerobic sequencing batch biofilm reactor (ASBBR treating cane vinasse at 55ºC

    Directory of Open Access Journals (Sweden)

    Maria Magdalena Ferreira Ribas

    2009-08-01

    Full Text Available The aim of this work was to investigate the anaerobic biomass formation capable of treating vinasse from the production of sugar cane alcohol, which was evolved within an anaerobic sequencing batch biofilm reactor (ASBBR as immobilized biomass on cubes of polyurethane foam at the temperature of 55ºC. The reactor was inoculated with mesophilic granular sludge originally treating poultry slaughterhouse wastewater. The evolution of the biofilm in the polyurethane foam matrices was assessed during seven experimental phases which were thus characterized by the changes in the organic matter concentrations as COD (1.0 to 20.0 g/L. Biomass characterization proceeded with the examination of sludge samples under optical and scanning electron microscopy. The reactor showed high microbial morphological diversity along the trial. The predominance of Methanosaeta-like cells was observed up to the organic load of 2.5 gCOD/L.d. On the other hand, Methanosarcinalike microorganisms were the predominant archaeal population within the foam matrices at high organic loading ratios above 3.3 gCOD/L.d. This was suggested to be associated to a higher specific rate of acetate consumption by the later organisms.Este trabalho investigou a formação de um biofilme anaeróbio capaz de tratar vinhaça da produção de álcool de cana-de-açúcar, que evoluiu dentro de um reator operado em bateladas seqüenciais com biofilme (ASBBR tendo a biomassa imobilizada em cubos de espuma de poliuretano na temperatura de 55ºC. O reator foi inoculado com lodo granular mesofílico tratando água residuária de abatedouro de aves. A evolução do biofilme nas matrizes de espuma de poliuretano foi observada durante sete fases experimentais que foram caracterizadas por mudanças nas concentrações de matéria orgânica como DQO (1,0 a 20,0 g/L. A caracterização da biomassa foi feita por exames de amostras do lodo em microscopia ótica e eletrônica de varredura. O reator apresentou

  3. A comparison study on the high-rate co-digestion of sewage sludge and food waste using a temperature-phased anaerobic sequencing batch reactor system.

    Science.gov (United States)

    Kim, Hyun-Woo; Nam, Joo-Youn; Shin, Hang-Sik

    2011-08-01

    Assessing contemporary anaerobic biotechnologies requires proofs on reliable performance in terms of renewable bioenergy recovery such as methane (CH(4)) production rate, CH(4) yield while removing volatile solid (VS) effectively. This study, therefore, aims to evaluate temperature-phased anaerobic sequencing batch reactor (TPASBR) system that is a promising approach for the sustainable treatment of organic fraction of municipal solid wastes (OFMSW). TPASBR system is compared with a conventional system, mesophilic two-stage anaerobic sequencing batch reactor system, which differs in operating temperature of 1st-stage. Results demonstrate that TPASBR system can obtain 44% VS removal from co-substrate of sewage sludge and food waste while producing 1.2m(3)CH(4)/m(3)(system)/d (0.2m(3)CH(4)/kgVS(added)) at organic loading rate of 6.1gVS/L/d through the synergy of sequencing-batch operation, co-digestion, and temperature-phasing. Consequently, the rapid and balanced anaerobic metabolism at thermophilic stage makes TPASBR system to afford high organic loading rate showing superior performance on OFMSW stabilization. PMID:21600764

  4. Neutronics and Depletion Methods for Parametric Studies of Fluoride Salt Cooled High Temperature Reactors with Slab Fuel Geometry and Multi-Batch Fuel Management Schemes

    International Nuclear Information System (INIS)

    The Advanced High Temperature Reactor (AHTR) is a 3400 MWth fluoride salt cooled high temperature reactor (FHR) that uses TRISO particle fuel compacted into slabs rather than spherical fuel pebbles or cylindrical fuel compacts. Simplified methods are required for parametric design studies such that analyzing the entire feasible design space for an AHTR is tractable. These simplifications include fuel homogenization techniques to increase the speed of neutron transport calculations in depletion analysis and equilibrium depletion analysis methods to analyze systems with multi-batch fuel management schemes. This paper presents three elements of significant novelty. First, the reactivity-equivalent physical transformation (RPT) methodology usually applied in systems with coated particle fuel in cylindrical and spherical geometries was extended to slab geometries. Secondly, based on this newly developed RPT method for slab geometries, a methodology that uses Monte Carlo depletion approaches was further developed to search for the maximum discharge burnup in a multi-batch system by iteratively estimating the beginning of equilibrium cycle composition and sampling different discharge burnups. This iterative equilibrium depletion search (IEDS) method fully defines an equilibrium fuel cycle (keff, power, flux and composition evolutions across space and time), but is computationally demanding, although feasible on single-processor workstations. Finally, an analytical method, the non-linear reactivity model, was developed by expanding the linear reactivity model to include an arbitrary number of higher order terms to extrapolate single-batch depletion results to estimate the maximum discharge burnup and BOEC keff in systems with multi-batch fuel management schemes. Results from this method were benchmarked against equilibrium depletion analysis results using the IEDS.

  5. Biogenic Hydrogen Conversion of De-Oiled Jatropha Waste via Anaerobic Sequencing Batch Reactor Operation: Process Performance, Microbial Insights, and CO2 Reduction Efficiency

    Directory of Open Access Journals (Sweden)

    Gopalakrishnan Kumar

    2014-01-01

    Full Text Available We report the semicontinuous, direct (anaerobic sequencing batch reactor operation hydrogen fermentation of de-oiled jatropha waste (DJW. The effect of hydraulic retention time (HRT was studied and results show that the stable and peak hydrogen production rate of 1.48 L/L*d and hydrogen yield of 8.7 mL H2/g volatile solid added were attained when the reactor was operated at HRT 2 days (d with a DJW concentration of 200 g/L, temperature 55°C, and pH 6.5. Reduced HRT enhanced the production performance until 1.75 d. Further reduction has lowered the process efficiency in terms of biogas production and hydrogen gas content. The effluent from hydrogen fermentor was utilized for methane fermentation in batch reactors using pig slurry and cow dung as seed sources. The results revealed that pig slurry was a feasible seed source for methane generation. Peak methane production rate of 0.43 L CH4/L*d and methane yield of 20.5 mL CH4/g COD were observed at substrate concentration of 10 g COD/L, temperature 30°C, and pH 7.0. PCR-DGGE analysis revealed that combination of celluloytic and fermentative bacteria were present in the hydrogen producing ASBR.

  6. Biogenic Hydrogen Conversion of De-Oiled Jatropha Waste via Anaerobic Sequencing Batch Reactor Operation: Process Performance, Microbial Insights, and CO2 Reduction Efficiency

    Science.gov (United States)

    Lin, Chiu-Yue

    2014-01-01

    We report the semicontinuous, direct (anaerobic sequencing batch reactor operation) hydrogen fermentation of de-oiled jatropha waste (DJW). The effect of hydraulic retention time (HRT) was studied and results show that the stable and peak hydrogen production rate of 1.48 L/L∗d and hydrogen yield of 8.7 mL H2/g volatile solid added were attained when the reactor was operated at HRT 2 days (d) with a DJW concentration of 200 g/L, temperature 55°C, and pH 6.5. Reduced HRT enhanced the production performance until 1.75 d. Further reduction has lowered the process efficiency in terms of biogas production and hydrogen gas content. The effluent from hydrogen fermentor was utilized for methane fermentation in batch reactors using pig slurry and cow dung as seed sources. The results revealed that pig slurry was a feasible seed source for methane generation. Peak methane production rate of 0.43 L CH4/L∗d and methane yield of 20.5 mL CH4/g COD were observed at substrate concentration of 10 g COD/L, temperature 30°C, and pH 7.0. PCR-DGGE analysis revealed that combination of celluloytic and fermentative bacteria were present in the hydrogen producing ASBR. PMID:24672398

  7. Engineering development of slurry bubble column reactor (SBCR) technology. Quarterly report, January 1--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Toseland, B.A.; Tischer, R.E.

    1997-12-31

    The major technical objectives of this program are threefold: (1) to develop the design tools and a fundamental understanding of the fluid dynamics of a slurry bubble column reactor to maximize reactor productivity; (2) to develop the mathematical reactor design models and gain an understanding of the hydrodynamic fundamentals under industrially relevant process conditions; and (3) to develop an understanding of the hydrodynamics and their interaction with the chemistries occurring in the bubble column reactor. Successful completion of these objectives will permit more efficient usage of the reactor column and tighter design criteria, increase overall reactor efficiency, and ensure a design that leads to stable reactor behavior when scaling up to large diameter reactors. The main part of this report describes tracer studies of slurry bubble column hydrodynamics during methanol synthesis.

  8. Application of multivariate statistical projection techniques for monitoring a sequencing batch reactor (SBR); Aplicacion de tecnicas estadisticas de proyeccion multivariante para la monitorizacion de un SBR

    Energy Technology Data Exchange (ETDEWEB)

    Aguado Garcia, D.; Ferrer Riquelme, A. J.; Seco Torrecillas, A.; Ferrer Polo, J.

    2006-07-01

    Due to the increasingly stringent effluents quality requirements imposed by the regulations, monitoring wastewater treatment plants (WWTP) becomes extremely important in order to achieve efficient process operations. Nowadays, at modern WWTP large number of online process variables are collected and these variable are usually highly correlated. Therefore, appropriate techniques are required to extract the information from the huge amount of collected data. In this work, the application of multivariate statistical projection techniques is presented as an effective strategy for monitoring a sequencing batch reactor (SBR) operated for enhanced biological phosphorus removal. (Author)

  9. Using a Statistical Model to Examine the Effect of COD: SO42− Ratio, HRT and LA Concentration on Sulfate Reduction in an Anaerobic Sequencing Batch Reactor

    OpenAIRE

    Rajesh Singh; Chungman Moon; Sathyanarayan S. Veeravalli; Saravanan R. Shanmugam; Subba Rao Chaganti; Jerald A. Lalman

    2014-01-01

    Taguchi statistical design, an orthogonal array (OA) method, was used to study the impact of the COD/SO42− ratio, hydraulic retention time (HRT) and linoleic acid (LA) concentration on sulfate (SO42−) reduction in an anaerobic sequencing batch reactor using glucose as the electron donor. Based on the OA, optimum condition for maximum SO42− reduction was evaluated. Increasing the COD/SO42− ratio and HRT caused decreasing SO42− reduction while increased SO42− reduction was observed with increas...

  10. Effects of Bio-sludge Concentration and Dilution Rate on the Efficiency of Sequencing Batch Reactor (SBR) System for Textile Wastewater Treatment

    OpenAIRE

    Suntud Sirianuntapiboon; Sarun Maneewon

    2012-01-01

    The color removal efficiency of a sequencing batch reactor (SBR) system with synthetic textile wastewater (STWW) containing 80 mg/L disperse dye increased with the increase of mixed liquor suspended solids (MLSS) or solids retention time (SRT). The color removal efficiency was over 98% at an MLSS of 4,000 mg/L and SRT of over 25 days. Also, the color removal efficiency decreased with the increase of dye concentration. Both disperse blue 60 and disperse red 60 repressed the growths and activit...

  11. Kinetic modeling and microbial assessment by fluorescent in situ hybridization in anaerobic sequencing batch biofilm reactors treating sulfate-rich wastewater

    Directory of Open Access Journals (Sweden)

    A. J. Silva

    2011-06-01

    Full Text Available This paper reports the results of applying anaerobic sequencing batch biofilm reactors (AnSBBR for treating sulfate-rich wastewater. The reactor was filled with polyurethane foam matrices or with eucalyptus charcoal, used as the support for biomass attachment. Synthetic wastewater was prepared with two ratios between chemical oxygen demand (COD and sulfate concentration (COD/SO4(2- of 0.4 and 3.2. For a COD/SO4(2- ratio of 3.2, the AnSBBR performance was influenced by the support material used; the average levels of organic matter removal were 67% and 81% in the reactors filled with polyurethane foam and charcoal, respectively, and both support materials were associated with similar levels of sulfate reduction (above 90%. In both reactors, sulfate-reducing bacteria (SRB represented more than 65% of the bacterial community. The kinetic model indicated equilibrium between complete- and incomplete-oxidizing SRB in the reactor filled with polyurethane foam and predominantly incomplete-oxidizing SRB in the reactor filled with charcoal. Methanogenic activity seems to have been the determining factor to explain the better performance of the reactor filled with charcoal to remove organic matter at a COD/SO4(2- ratio of 3.2. For a COD/SO4(2- ratio of 0.4, low values of sulfate reduction (around 32% and low reaction rates were observed as a result of the small SRB population (about 20% of the bacterial community. Although the support material did not affect overall performance for this condition, different degradation pathways were observed; incomplete oxidation of organic matter by SRB was the main kinetic pathway and methanogenesis was negligible in both reactors.

  12. Treatment of mature landfill leachate by internal micro-electrolysis integrated with coagulation: A comparative study on a novel sequencing batch reactor based on zero valent iron

    International Nuclear Information System (INIS)

    Highlights: ► Specifically-designed SIME reactor for treatment of mature landfill leachate. ► Excellent removal efficiencies of COD (86.1%), color (95.3%), and HA (81.8%). ► Combination effect of IME without aeration and IME with aeration. ► Optimal pH of 5, Fe/C of 1:1, gas flow rate of 80 L h−1, and H2O2 of 100 mg L−1. - Abstract: A comparative study of treating mature landfill leachate with various treatment processes was conducted to investigate whether the method of combined processes of internal micro-electrolysis (IME) without aeration and IME with full aeration in one reactor was an efficient treatment for mature landfill leachate. A specifically designed novel sequencing batch internal micro-electrolysis reactor (SIME) with the latest automation technology was employed in the experiment. Experimental data showed that combined processes obtained a high COD removal efficiency of 73.7 ± 1.3%, which was 15.2% and 24.8% higher than that of the IME with and without aeration, respectively. The SIME reactor also exhibited a COD removal efficiency of 86.1 ± 3.8% to mature landfill leachate in the continuous operation, which is much higher (p 2O2, were optimized. All results show that the SIME reactor is a promising and efficient technology in treating mature landfill leachate.

  13. Study of microbial flora aclimatization to increasing concentrations of efluents “in natura” of the industry of fishing in reactors of sequential batch

    Directory of Open Access Journals (Sweden)

    Maria Alice Z. Coelho

    2009-12-01

    Full Text Available The present work analyzes the adaptation and activity of a sludge belonging to a UASB reactor of the wastewater treatment unit from a fish processing industry, in a bench scale Sequencing Batch Reactor for biological nitrogen removal. The sludge adaptation was carried using an increasing sequence of the applied load from 1:3.33; 1:2.5; 1:2.0; regarding to volume of in natura wastewater : synthetic sewage. The initial inocullum concentration employed was 20 g VSS / L. During this period COD, nitrate and ammonia concentrations were followed and a removal about 80% of the organic matter and up to 97% of nitrogen could be achieved. An experiment employing the greater dilution (1:3.33 with 0.5% salt (as NaCl was also carried to evaluate the salinity effect which is considered in the analysis of the results herein presented.

  14. Effect of feeding time on the performance of a sequencing batch reactor treating a mixture of 4-CP and 2,4-DCP.

    Science.gov (United States)

    Sahinkaya, Erkan; Dilek, Filiz B

    2007-06-01

    This paper investigated the biodegradation kinetics of 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) separately in batch reactors and mixed in sequencing batch reactors (SBRs). Batch reactor experiments showed that both 4-CP and 2,4-DCP began to inhibit their own degradation at 53 and 25 mg l(-1), respectively, and that the Haldane equation gave a good fit to the experimental data because r(2) values were higher than 0.98. The maximum specific degradation rates (q(m)) were 130.3 and 112.4 mg g(-1) h for 4-CP and 2,4-DCP, respectively. The values of the half saturation (K(s)) and self-inhibition constants (K(i)) were 34.98 and 79.74 mg l(-1) for 4-CP, and 13.77 and 44.46 mg l(-1) for 2,4-DCP, respectively. The SBR was fed with a mixture of 220 mg l(-1) of 4-CP, 110 mg l(-1) of 2,4-DCP, and 300 mg l(-1) of peptone as biogenic substrate at varying feeding periods (0-8h) to evaluate the effect of feeding time on the performance of the SBR. During SBR operation, in addition to self-inhibition, 4-CP degradation was strongly and competitively inhibited by 2,4-DCP. The inhibitory effects were particularly pronounced during short feeding periods because of higher chlorophenol peak concentrations in the reactor. The competitive inhibition constant (K(ii)) of 2,4-DCP on 4-CP degradation was 0.17 mg l(-1) when the reactor was fed instantaneously (0 h feeding). During longer feedings, increased removal/loading rates led to lower chlorophenol peak concentrations at the end of feeding. Therefore, in multi-substrate systems feeding time plus reaction time should be determined based on both degradation kinetics and substrate interaction. During degradation, the meta cleavage of 4-chlorocatechol resulted in accumulation of a yellowish color because of the formation of 5-chloro-2-hydroxymuconic semialdehyde (CHMS), which was further metabolized. Isolation and enrichment of the chlorophenols-degrading culture suggested Pseudomonas sp. and Pseudomonas stutzeri to be the

  15. Effect of surfactant-coated iron oxide nanoparticles on the effluent water quality from a simulated sequencing batch reactor treating domestic wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Sangchul, E-mail: sangchul.hwang@upr.edu [Department of Civil Engineering, University of Puerto Rico, Mayaguez, PR 00681 (Puerto Rico); Martinez, Diana [Department of Civil Engineering, University of Puerto Rico, Mayaguez, PR 00681 (Puerto Rico); Perez, Priscilla [Department of Biology, University of Puerto Rico, Mayaguez, PR 00681 (Puerto Rico); Rinaldi, Carlos [Department of Chemical Engineering, University of Puerto Rico, Mayaguez, PR 00681 (Puerto Rico)

    2011-12-15

    This study was conducted to evaluate the effect of commercially available engineered iron oxide nanoparticles coated with a surfactant (ENP{sub Fe-surf}) on effluent water quality from a lab-scale sequencing batch reactor as a model secondary biological wastewater treatment. Results showed that {approx}8.7% of ENP{sub Fe-surf} applied were present in the effluent stream. The stable presence of ENP{sub Fe-surf} was confirmed by analyzing the mean particle diameter and iron concentration in the effluent. Consequently, aqueous ENP{sub Fe-surf} deteriorated the effluent water quality at a statistically significant level (p < 0.05) with respect to soluble chemical oxygen demand, turbidity, and apparent color. This implied that ENP{sub Fe-surf} would be introduced into environmental receptors through the treated effluent and could potentially impact them. - Highlights: > Surfactant-coated engineered iron oxide nanoparticles (ENP{sub Fe-surf}) were assessed. > Effluent quality was analyzed from a sequencing batch reactor with ENP{sub Fe-surf}. > {approx}8.7% of ENP{sub Fe-surf} applied was present in the effluent. > ENP{sub Fe-surf} significantly (p < 0.05) deteriorated the effluent water quality. > Stable fraction of ENP{sub Fe-surf} will be introduced into environmental receptors. - Stable presence of surfactant-coated engineered iron oxides nanoparticles deteriorated the effluent water quality at a statistically significant level (p < 0.05).

  16. Equilibrium studies on hydrolysis of urea in a semi-batch reactor for production of ammonia to reduce hazardous pollutants from flue gases

    International Nuclear Information System (INIS)

    The increasing environmental awareness and the mandate of the pollution control agencies in various part of country for lowering emission of air pollutants such as CO2, NOx, SO2 and fly ash emissions, has increased the urgency for reviewing options and alternatives to accomplish the above objective. The addition of ammonia into the flue gas stream as a conditioning agent is found to be used in recent years for the reduction of air pollutants. Flue gas conditioning requires in situ generation of ammonia as the transportation and storage of anhydrous ammonia is hazardous in nature. The equilibrium study on hydrolysis of urea was done in a semi-batch glass reactor to investigate the effect of reaction temperature, initial feed concentration and stirring speed on ammonia production. Few experiments were carried out in a semi-batch reactor at atmospheric pressure by using different concentration of urea solution from 10 to 40 wt% of urea to water and equilibrium study has been done. The study reveals that conversion increases exponentially with an increase in temperature but the conversion decreases with increase in the inlet feed concentration of urea solution. Furthermore, the effect of stirring speed on conversion has also been studied and it found that conversion increases with increase in stirring speed.

  17. Effect of surfactant-coated iron oxide nanoparticles on the effluent water quality from a simulated sequencing batch reactor treating domestic wastewater

    International Nuclear Information System (INIS)

    This study was conducted to evaluate the effect of commercially available engineered iron oxide nanoparticles coated with a surfactant (ENPFe-surf) on effluent water quality from a lab-scale sequencing batch reactor as a model secondary biological wastewater treatment. Results showed that ∼8.7% of ENPFe-surf applied were present in the effluent stream. The stable presence of ENPFe-surf was confirmed by analyzing the mean particle diameter and iron concentration in the effluent. Consequently, aqueous ENPFe-surf deteriorated the effluent water quality at a statistically significant level (p Fe-surf would be introduced into environmental receptors through the treated effluent and could potentially impact them. - Highlights: → Surfactant-coated engineered iron oxide nanoparticles (ENPFe-surf) were assessed. → Effluent quality was analyzed from a sequencing batch reactor with ENPFe-surf. → ∼8.7% of ENPFe-surf applied was present in the effluent. → ENPFe-surf significantly (p Fe-surf will be introduced into environmental receptors. - Stable presence of surfactant-coated engineered iron oxides nanoparticles deteriorated the effluent water quality at a statistically significant level (p < 0.05).

  18. Anaerobic digestion of solid waste in RAS: Effect of reactor type on the biochemical acidogenic potential (BAP) and assessment of the biochemical methane potential (BMP) by a batch assay

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Letelier-Gordo, Carlos Octavio; Lund, Ivar

    2015-01-01

    Anaerobic digestion is a way to utilize the potential energy contained in solid waste produced in recirculating aquaculture systems (RASs), either by providing acidogenic products for driving heterotrophic denitrification on site or by directly producing combustive methane. In this study the...... design of an acidogenic continuously stirred reactor tank in a RAS single-sludge denitrification set-up. The biochemical methane potential of the sludge was estimated to 318 ± 29 g CH4 g-1 TVS0 by a batch assay and represented a higher utility of the solid waste when comparing the methane yield with the...... biochemical acidogenic potential of solid waste from juvenile rainbow trout was evaluated by measuring the yield of volatile fatty acids (VFA) during anaerobic digestion by batch or fed-batch reactor operation at hydrolysis time (HT) / hydraulic retention time (HRT) of 1, 5, or 10 days (and for batch...

  19. Anaerobic digestion of kitchen wastes in a single-phased anaerobic sequencing batch reactor(ASBR) with gas-phased absorb of CO2

    Institute of Scientific and Technical Information of China (English)

    ZHANG Bo; HE Zheng-guang; ZHANG Li-li; XU Jian-bo; SHI Hong-zhuan; CAI Wei-min

    2005-01-01

    The performance of the single-stage anaerobic digestion of kitchen wastes was investigated in an anaerobic sequencing batch reactor(ASBR) with gas-phased absorb of CO2. The ASBR was operated at four chemical oxygen demand(COD) loading rates, 2.8,respectively. The operation of the reactor with gas-phased absorb of CO2 was stable in spite of the low pH (2.6-3.9) and high concentration of TS(142 g/L) of input mixture. The output volatile fatty acid(VFA) concentration was between 2.7-4.7 g/L and had no inhibition on the methanogenic microorganism. The reactor without gas-phased absorb of CO2 became acidified when the total COD alkaline will be required to keep pH in the appropriate range for the methanogenic microorganism based on theoretical calculation. Gasphased absorb of CO2 effectively reduced the alkaline consumption, hence avoided excessive cation into the reactor.

  20. Enhancement of the performance of an anaerobic sequencing batch reactor treating low-strength wastewater through implementation of a variable stirring rate program

    Directory of Open Access Journals (Sweden)

    Rodrigues J. A. D.

    2004-01-01

    Full Text Available This work focuses on enhancement of the performance of an anaerobic sequencing batch reactor with a six-vertical-blade-disk-turbine impeller, containing granulated biomass treating low-strength synthetic wastewater, through a study of the feasibility of implementing a variable stirring rate program. The reactor was operated at 30ºC and a six-hour cycle was used to treat approximately 2.0 L of the synthetic substrate with a chemical oxygen demand (COD of nearly 500 mg/L. Two different stirring rate program were implemented: a constant rate of 50 rpm and a variable rate consisting of 75 rpm for one hour, 50 rpm for four hours and 25 rpm for 0.5 hour. The last 0.5 hour of the cycle was used for the settling step. In both cases, a very short start-up period and unfiltered and filtered substrate removal efficiencies of 81% and 88%, respectively, were attained. However, use of the variable stirring rate enhanced efficiency of the reactor dynamics without impairing biomass morphology, thus resulting in a reduction in the total cycle time and a possible decrease in energy consumption. Additionally, a simplified model of the anaerobic metabolic activity, using apparent kinetic parameters, was proposed as a consecutive first-order kinetic model with substrate and total volatile acid residual concentrations in order to analyze how the variable stirring rate affects reactor performance.

  1. Investigation of tetrafluoromethane as a plasma gas in a very high pressure/low current dc batch reactor by means of 3D MHD modelling

    International Nuclear Information System (INIS)

    This paper deals with 3D MHD modelling of the behaviour of a tetrafluoromethane (CF4) plasma arc in a batch reactor under peculiar conditions of low current (0.35 A) and very high pressure (50 atm). The first part of the manuscript presents results for a horizontal configuration of the reactor, as is undertaken experimentally. The model has led to the understanding of the instabilities observed experimentally for such unusual operating conditions. The curved shape of the arc and the sliding of the anodic arc root along the electrode have been revealed to be the source of the experimental instabilities. The latter part of the manuscript investigates the effect of two vertical configurations of the reactor; with a cathode at the top and cathode at the bottom to overcome the instabilities. In these reactor configurations, the arc is much more stable and stays centred in the middle of the electrodes. These configurations are more suitable for the stability of the arc discharge, but have to be verified experimentally. (paper)

  2. Anaerobic digestion of solid waste in RAS: Effect of reactor type on the biochemical acidogenic potential (BAP) and assessment of the biochemical methane potential (BMP) by a batch assay

    OpenAIRE

    Suhr, Karin Isabel; Letelier-Gordo, Carlos Octavio; Lund, Ivar

    2015-01-01

    Anaerobic digestion is a way to utilize the potential energy contained in solid waste produced in recirculating aquaculture systems (RASs), either by providing acidogenic products for driving heterotrophic denitrification on site or by directly producing combustive methane. In this study the biochemical acidogenic potential of solid waste from juvenile rainbow trout was evaluated bymeasuring the yield of volatile fatty acids (VFA) during anaerobic digestion by batch or fed-batch reactor opera...

  3. Reactor safety research programs. Quarterly progress report, January 1--March 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Romano, A. J. [comp.

    1978-04-01

    Progress is summarized in the following areas: (1) gas reactor safety evaluation, (2) THOR code development, (3) foreign code review, (4) SSC code development, (5) LMFBR and LWR safety experiments, (6) fast reactor safety code validation, (7) stress corrosion cracking of PWR steam generator tubing, and (8) technical coordination of structural integrity.

  4. Advanced Reactor Safety Research Program quarterly report, April--June 1977. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-11-01

    Information is presented concerning accident energetics; core debris behavior; sodium containment and structural integrity; research for elevated temperature design criteria; fuel motion detection; ACPR fuel motion system; and advanced reactor safety research assessment.

  5. Oak Ridge reactor shutdown maintenance and surveillance quarterly report, July, August, and September 1989

    International Nuclear Information System (INIS)

    The Department of Energy ordered the Oak Ridge Reactor to be placed in permanent shutdown on July 14, 1987. Maintenance activities, both mechanical and instrument, were essentially routine in nature. Shutdown activities are discussed for this reporting period

  6. Advanced reactor safety research quarterly report, October-December 1982. Volume 24

    Energy Technology Data Exchange (ETDEWEB)

    None

    1984-04-01

    This report describes progress in a number of activities dealing with current safety issues relevant to both light water reactors (LWRs) and breeder reactors. The work includes a broad range of experiments to simulate accidental conditions to provide the required data base to understand important accident sequences and to serve as a basis for development and verification of the complex computer simulation models and codes used in accident analysis and licensing reviews. Such a program must include the development of analytical models, verified by experiment, which can be used to predict reactor and safety system performance under a broad variety of abnormal conditions. Current major emphasis is focused on providing information to NRC relevant to (1) its deliberations and decisions dealing with severe LWR accidents and (2) its safety evaluation of the proposed Clinch River Breeder Reactor.

  7. 40 CFR 63.1408 - Aggregate batch vent stream provisions.

    Science.gov (United States)

    2010-07-01

    ... from all aggregate batch vent streams in the compliance demonstration required for reactor batch... comply with the mass emission limit for reactor batch process vents. ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Aggregate batch vent stream...

  8. PEMBUATAN BAHAN BAKU SPREADS KAYA KAROTEN DARI MINYAK SAWIT MERAH MELALUI INTERESTERIFIKASI ENZIMATIK MENGGUNAKAN REAKTOR BATCH [Preparation of Red Palm Oil Based-Spreads Stock Rich in Carotene Through Enzymatic Interesterification in Batch-type Reactor

    Directory of Open Access Journals (Sweden)

    Nur Wulandari1,2

    2012-12-01

    Full Text Available Enzymatic interesterification of red palm oil (a mixture of red palm olein/RPO and red palm stearin/RPS in 1:1 weight ratio and coconut oil (CNO blends of varying proportions using a non-specific immobilized Candida antartica lipase (Novozyme 435 was studied for the preparation of spread stock. The interesterification reaction was held in a batch-type reactor. Two substrate blends were chosen for the production of spread stock i.e. 77.5:22,5 and 82.5:17.5 (RPO/RPS:CNO, by weight through enzymatic interesterification in three different reaction times (2, 4, and 6 hours. The interesterification reactions were conducted at 60°C, 200 rpm agitation speed and 10% of Novozyme 435. The interesterified products were evaluated for their physical characteristics (slip melting point or SMP and solid fat content or SFC and chemical characteristics (carotene retention, moisture content, and free fatty acid/FFA content. All of the interesterified products had lower SFC and SMP as compared to the initial blends. The SMP and SFC increased in longer reaction times. The SMP ranged from 30.8°C to 34.9°C. The carotene retention ranged from 74.80% to 81.08%, while the moisture content and FFA content increased in longer reaction times. The interesterified products had desirable physical properties for possible use as a spread stock rich in carotene.

  9. Population dynamics of bacteria for phosphorus removal in sequencing batch reactor (SBR) activated sludge processes. Kaibunshiki kassei odeiho ni okeru datsu rin tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Okada, M.; Ueno, Y.; Lin, C.; Murakami, A. (Tokyo University of Agriculture and Technology, Tokyo (Japan))

    1990-01-10

    As the phosphorus removal processes, chemical methods and biological methods are considered. This paper discussed a biological phosphorus removal method. Laboratory experiments of phosphorus removal in sequencing batch reactor (SBR) activated sludge processes were operated using synthetic waste water to clarify the effects of solid retention time (SRT) and organic substrates on the accumulation of bacteria having phosphorus removal ability (bio-P-bacteria). The accumulation of bio-P-bacteria was enhanced by large fluctuation in concentration of organic substances in the reactor fed in a short period of time under anaerobic condition. However, the accumulation did not be enhanced in the reactor operated with SRT less than 25 d. The specific growth rates of bio-P-bacteria were estimated to a range from 0.033/d to 0.035/d in the SBR activated sludge processes fed with glucose and polypeptone as substrates. Therefore, large SRT is necessary for the accumulation of bio-P-bacteria. 18 refs., 10 figs., 1 tab.

  10. Optimization of the moving-bed biofilm sequencing batch reactor (MBSBR) to control aeration time by kinetic computational modeling: Simulated sugar-industry wastewater treatment.

    Science.gov (United States)

    Faridnasr, Maryam; Ghanbari, Bastam; Sassani, Ardavan

    2016-05-01

    A novel approach was applied for optimization of a moving-bed biofilm sequencing batch reactor (MBSBR) to treat sugar-industry wastewater (BOD5=500-2500 and COD=750-3750 mg/L) at 2-4h of cycle time (CT). Although the experimental data showed that MBSBR reached high BOD5 and COD removal performances, it failed to achieve the standard limits at the mentioned CTs. Thus, optimization of the reactor was rendered by kinetic computational modeling and using statistical error indicator normalized root mean square error (NRMSE). The results of NRMSE revealed that Stover-Kincannon (error=6.40%) and Grau (error=6.15%) models provide better fits to the experimental data and may be used for CT optimization in the reactor. The models predicted required CTs of 4.5, 6.5, 7 and 7.5h for effluent standardization of 500, 1000, 1500 and 2500mg/L influent BOD5 concentrations, respectively. Similar pattern of the experimental data also confirmed these findings. PMID:26943932

  11. Treatment of low-strength wastewater using immobilized biomass in a sequencing batch external loop reactor: influence of the medium superficial velocity on the stability and performance

    Directory of Open Access Journals (Sweden)

    Camargo E.F.M.

    2002-01-01

    Full Text Available An anaerobic sequencing batch bioreactor with external circulation of the liquid phase wherein the biomass was immobilized on a polyurethane foam matrix was analyzed, focussing on the influence of the liquid superficial velocity on the reactor's stability and efficiency. Eight-hour cycles were carried out at 30ºC treating glucose-based synthetic wastewater around 500 mgDQO/L. The performance of the reactor was assessed without circulation and with circulating liquid superficial velocity between 0.034 and 0.188 cm/s. The reactor attained operating stability and a high organic matter removal was achieved when liquid was circulated. A first order model was used to evaluate the influence of the liquid superficial velocity (vS, resulting in an increase in the apparent first order parameter when vS increased from 0.034 to 0.094 cm/s. The parameter value remained unchangeable when 0.188 cm/s was applied, indicating that beyond this value no improvement on liquid mass transfer was observed. Moreover, the necessary time to reach the final removal efficiency decreased when liquid circulation was applied, indicating that a 3-hour cycle could be enough.

  12. Biological treatment of thin-film transistor liquid crystal display (TFT-LCD) wastewater using aerobic and anoxic/oxic sequencing batch reactors.

    Science.gov (United States)

    Lei, Chin-Nan; Whang, Liang-Ming; Chen, Po-Chun

    2010-09-01

    The amount of pollutants produced during manufacturing processes of thin-film transistor liquid crystal display (TFT-LCD) substantially increases due to an increasing production of the opto-electronic industry in Taiwan. This study presents the treatment performance of one aerobic and one anoxic/oxic (A/O) sequencing batch reactors (SBRs) treating synthetic TFT-LCD wastewater containing dimethyl sulfoxide (DMSO), monoethanolamine (MEA), and tetra-methyl ammonium hydroxide (TMAH). The long-term monitoring results for the aerobic and A/O SBRs demonstrate that stable biodegradation of DMSO, MEA, and TMAH can be achieved without any considerably adverse impacts. The ammonium released during MEA and TMAH degradation can also be completely oxidized to nitrate through nitrification in both SBRs. Batch studies on biodegradation rates for DMSO, MEA, and TMAH under anaerobic, anoxic, and aerobic conditions indicate that effective MEA degradation can be easily achieved under all three conditions examined, while efficient DMSO and TMAH degradation can be attained only under anaerobic and aerobic conditions, respectively. The potential odor problem caused by the formation of malodorous dimethyl sulfide from DMSO degradation under anaerobic conditions, however, requires insightful consideration in treating DMSO-containing wastewater. PMID:20705321

  13. Comparision of real waste (MSW and MPW) pyrolysis in batch reactor over different catalysts. Part I: product yields, gas and pyrolysis oil properties.

    Science.gov (United States)

    Ateş, Funda; Miskolczi, Norbert; Borsodi, Nikolett

    2013-04-01

    Pyrolysis of municipal solid waste (MSW) and municipal plastic waste (MPW) have been investigated in batch reactor at 500, 550 and 600°C both in absence and presence of catalysts (Y-zeolite, β-zeolite, equilibrium FCC, MoO3, Ni-Mo-catalyst, HZSM-5 and Al(OH)3). The effect of the parameters on the product properties was investigated. Products were characterized using gas-chromatography, GC/MS, (13)C NMR. Yields of volatile fractions increased, while reaction time necessity for the total cracking decreased in the presence of catalysts. Catalysts have productivity and selectivity in converting aliphatic hydrocarbons to aromatic and cyclic compounds in oil products. Gases from MSW consisted of hydrogen CO, CO2, while exclusively hydrogen and hydrocarbons were detected from MPW. Catalyst efficiency was higher using MPW than MSW. Pyrolysis oils contained aliphatic hydrocarbons, aromatics, cyclic compounds and less ketones, alcohols, acids or esters depending on the raw materials. PMID:23455219

  14. Exploring the controls of soil biogeochemistry in a restored coastal wetland using object-oriented computer simulations of uptake kinetics and thermodynamic optimization in batch reactors

    Science.gov (United States)

    Payn, R. A.; Helton, A. M.; Poole, G.; Izurieta, C.; Bernhardt, E. S.; Burgin, A. J.

    2012-12-01

    Many hypotheses have been proposed to predict patterns of biogeochemical redox reactions based on the availability of electron donors and acceptors and the thermodynamic theory of chemistry. Our objective was to develop a computer model that would allow us to test various alternatives of these hypotheses against data gathered from soil slurry batch reactors, experimental soil perfusion cores, and in situ soil profile observations from the restored Timberlake Wetland in coastal North Carolina, USA. Software requirements to meet this objective included the ability to rapidly develop and compare different hypothetical formulations of kinetic and thermodynamic theory, and the ability to easily change the list of potential biogeochemical reactions used in the optimization scheme. For future work, we also required an object pattern that could easily be coupled with an existing soil hydrologic model. These requirements were met using Network Exchange Objects (NEO), our recently developed object-oriented distributed modeling framework that facilitates simulations of multiple interacting currencies moving through network-based systems. An initial implementation of the object pattern was developed in NEO based on maximizing growth of the microbial community from available dissolved organic carbon. We then used this implementation to build a modeling system for comparing results across multiple simulated batch reactors with varied initial solute concentrations, varied biogeochemical parameters, or varied optimization schemes. Among heterotrophic aerobic and anaerobic reactions, we have found that this model reasonably predicts the use of terminal electron acceptors in simulated batch reactors, where reactions with higher energy yields occur before reactions with lower energy yields. However, among the aerobic reactions, we have also found this model predicts dominance of chemoautotrophs (e.g., nitrifiers) when their electron donor (e.g., ammonium) is abundant, despite the

  15. A start-up of psychrophilic anaerobic sequence batch reactor digesting a 35 % total solids feed of dairy manure and wheat straw

    OpenAIRE

    Saady, Noori M. Cata; Massé, Daniel I.

    2015-01-01

    Zero liquid discharge is currently an objective in livestock manure management to minimize water pollution. This paper reports the start-up phase of a novel psychrophilic (20 °C) dry anaerobic digestion of dairy manure with bedding fed at 35 % total solids and an organic loading rate of 3.0 g total chemical oxygen demand kg−1 inoculum day−1 in anaerobic sequence batch reactors. The specific methane (CH4) yield ranged from 165.4 ± 9.8 to 213.9 ± 13.6 NL CH4 kg−1 volatile solids (VS) with an ov...

  16. Influence of pH, concentration and ionic strength during batch and flow-through continuous stirred reactor experiments of Sr2+-adsorption onto montmorillonite

    International Nuclear Information System (INIS)

    Sorption/desorption experiments in batch and continuous flow-through stirred reactor under different experimental conditions were carried out using montmorillonite (2+ amount desorbed at pH 4 is only half of the amount desorbed at pH 8, revealing that the retention of Sr2+ onto montmorillonite was enhanced at pH 4. The largest adsorption value was obtained at pH 8.0 ([KNO3] = 10-3 mol/L) with q m = 41.49 mg Sr2+/g from the Langmuir isotherm. The gradient of concentration acted as an increasing driving force since the amount of Sr2+ adsorbed increased as increasing of Sr2+ concentration during the flow-through experiments. (author)

  17. Notifiable events in facilities for fission of nuclear fuels in the Federal Republic of Germany. Nuclear power plants and research reactors with a maximum continuous thermal output of more than 50 kW. Third quarterly report 1997

    International Nuclear Information System (INIS)

    The report presents the survey and the scenarios of events reported from nuclear power plant and research reactors with a rated thermal output above 50 kW, covering the 3rd quarter of 1997. (orig./CB)

  18. Correlation between microbial diversity and toxicity of sludge treating synthetic wastewater containing 4-chlorophenol in sequencing batch reactors.

    Science.gov (United States)

    Zhao, Jianguo; Chen, Xiurong; Bao, Linlin; Bao, Zheng; He, Yixuan; Zhang, Yuying; Li, Jiahui

    2016-06-01

    The relationship between microbial diversity and sludge toxicity in the biotreatment of refractory wastewater was investigated. Synthetic wastewater containing 4-chlorophenol (4-CP) was treated by an activated sludge using a sequencing batch bioreactor (SBR). At the end of a single SBR cycle, a stable operation stage was reached when the 4-CP was not detected both in aqueous and sludge phases and the effluent COD was maintained at approximately 70 mg L(-1) for the blank and control sludge groups. Then, the diversity of the microorganisms and the sludge toxicity were measured. The results showed that the Microtox acute toxicity of the control sludge was higher than those of the blank sludge. The difference analysis of the microbial diversity between the blank and control sludge indicated that the sludge toxicity was closely related to microbial diversity. PMID:27016808

  19. Light-Water-Reactor safety research program. Quarterly progress report, January--March 1977

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-06-01

    The report summarizes the Argonne National Laboratory work performed during January, February, and March 1977 on water-reactor-safety problems. The following research and development areas are covered: (1) loss-of-coolant accident research: heat transfer and fluid dynamics; (2) transient fuel response and fission-product release program; (3) mechanical properties of zircaloy containing oxygen; and (4) steam-explosion studies.

  20. Advanced reactor safety research. Quarterly report, April-June 1982. Volume 22

    Energy Technology Data Exchange (ETDEWEB)

    None

    1983-10-01

    Overall objective of this work is to provide NRC a comprehensive data base essential to (1) defining key safety issues, (2) understanding risk-significant accident sequences, (3) developing and verifying models used in safety assessments, and (4) assuring the public that power reactor systems will not be licensed and placed in commercial service in the United States without appropriate consideration being given to their effects on health and safety. This report describes progress in a number of activities dealing with current safety issues relevant to both light water and breeder reactors. The work includes a broad range of experiments to simulate accidental conditions to provide the required data base to understand important accident sequences and to serve as a basis for development and verification of the complex computer simulation models and codes used in accident analysis and licensing reviews. Such a program must include the development of analytical models, verified by experiment, which can be used to predict reactor and safety system performance under a broad variety of abnormal conditions. Current major emphasis is focused on providing information to NRC relevant to (1) its deliberations and decisions dealing with severe LWR accidents, and (2) its safety evaluation of the proposed Clinch River Breeder Reactor.

  1. Removal of absorbable organic halides (aox) from recycled paper mill effluent using granular activated carbon-sequencing batch biofilm reactor (GAC-SBBR)

    International Nuclear Information System (INIS)

    Paper mills generate varieties of pollutants depending upon the type of the pulping process. Paper mill wastewaters have high chemical oxygen demand (COD) and colour, indicating high concentrations of recalcitrant organics. The study was conducted employing a Granular Activated Carbon - Sequencing Batch Biofilm Reactor (GAC-SBBR), containing 3.0 L working volume, operated in aerobic condition and packed with 200 g/L of 2-3 mm granular activated carbon (coconut shells) as a medium for biofilm growth. For the first couple of month, the HRT was 36 hours and the HRT of this reactor was adjusted to 24 hours in order to evaluate the performance of the system. The treated wastewater sample for these studies came from a recycle paper factory from MNI Sdn Bhd with 4 different samples characteristics. The adsorbable organic halides (AOX) to be determined and treated were Pentachlorophenol (PCP), 2,3,4,5-Tetrachlorophenol (2,3,4,5-TeCP), 2,4,6-Trichlorophenol (2,4,6-TCP), 2,4-Dichlorophenol ( 2,4-DCP), 2-Chlorophenol (CP) and phenol. Results showed that, the biofilm attached onto granular activated carbon (GAC) could substantially remove these recalcitrant in the wastewater. More over, results from the studies showed that high removal was achieved by the biofilm SBR with 10-100% removal of AOX and depending on HRT. (Author)

  2. 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

  3. Modeling chlorophenols degradation in sequencing batch reactors with instantaneous feed-effect of 2,4-DCP presence on 4-CP degradation kinetics.

    Science.gov (United States)

    Sahinkaya, Erkan; Dilek, Filiz B

    2007-08-01

    Two instantaneously fed sequencing batch reactors (SBRs), one receiving 4-chlorophenol (4-CP) (SBR4) only and one receiving mixture of 4-CP and 2,4-dichlorophenol (2,4-DCP) (SBRM), were operated with increasing chlorophenols concentrations in the feed. Complete degradation of chlorophenols and high-Chemical oxygen demand (COD) removal efficiencies were observed throughout the reactors operation. Only a fraction of biomass (competent biomass) was thought to be responsible for the degradation of chlorophenols due to required unique metabolic pathways. Haldane model developed based on competent biomass concentration fitted reasonably well to the experimental data at different feed chlorophenols concentrations. The presence of 2,4-DCP competitively inhibited 4-CP degradation and its degradation began only after complete removal of 2,4-DCP. Based on the experimental results, the 4-CP degrader's fraction in SBRM was estimated to be higher than that in SBR4 since 2,4-DCP degraders were also capable of degrading 4-CP due to similarity in the degradation pathways of both compounds. PMID:17091347

  4. Study of the Effect of SRT on Microbial Diversity in Laboratory-scale Sequencing Batch Reactors Using Acclimated and Non-Acclimated Seed

    KAUST Repository

    Tellez, Berenice

    2011-07-07

    Solids Retention Time (SRT) is an important design parameter in activated sludge wastewater treatment systems. In this study, the effect of SRT on the bacterial community structure and diversity was examined in replicate lab-scale activated sludge sequencing batch reactors were operated for a period of 8 weeks and seeded with acclimated or non-acclimated sludge. Four SBRs (acclimated) were set up as duplicates and operated at an SRT of 2 days, and another set of four SBRs (non-acclimated) were operated at an SRT of 10 days. To characterize the microbial community in the SBRs, 16S rRNA gene pyrosequencing was used to measure biodiversity and to assess the reproducibility and stability of the bacterial community structure in replicate reactors. Diversity results showed that SBRs operated at an SRT of 10 days are more diverse than SBRs operated at an SRT of 2 days. This suggests that engineering decision could enhance diversity in activated sludge systems. Cluster analysis based on phylogenetic information revealed that the bacterial community structure was not stable and replicated SBRs evolved differently.

  5. Comparison of three combined sequencing batch reactor followed by enhanced Fenton process for an azo dye degradation: Bio-decolorization kinetics study.

    Science.gov (United States)

    Azizi, A; Alavi Moghaddam, M R; Maknoon, R; Kowsari, E

    2015-12-15

    The purpose of this research was to compare three combined sequencing batch reactor (SBR) - Fenton processes as post-treatment for the treatment of azo dye Acid Red 18 (AR18). Three combined treatment systems (CTS1, CTS2 and CTS3) were operated to investigate the biomass concentration, COD removal, AR18 dye decolorization and kinetics study. The MLSS concentration of CTS2 reached 7200 mg/L due to the use of external feeding in the SBR reactor of CTS2. The COD concentration remained 273 mg/L and 95 mg/L (initial COD=3270 mg/L) at the end of alternating anaerobic-aerobic SBR with external feeding (An-A MSBR) and CTS2, respectively, resulting in almost 65% of Fenton process efficiency. The dye concentration of 500 mg/L was finally reduced to less than 10mg/L in all systems indicating almost complete AR18 decolorization, which was also confirmed by UV-vis analysis. The dye was removed following two successive parts as parts 1 and 2 with pseudo zero-order and pseudo first-order kinetics, respectively, in all CTSs. Higher intermediate metabolites degradation was obtained using HPLC analysis in CTS2. Accordingly, a combined treatment system can be proposed as an appropriate and environmentally-friendly system for the treatment of the azo dye AR18 in wastewater. PMID:26143197

  6. Nuclear reactor safety. Quarterly progress report, October 1--December 31, 1977

    International Nuclear Information System (INIS)

    Progress in reactor safety research is summarized. LWR studies include TRAC code development for thermal-hydraulic analysis of accidents, containment systems evaluation, and safety experiments. LMFBR studies include SIMMER code development and applications, modeling of core disruptive accidents, and safety test facilities studies. HTGR safety studies cover fission product release and transport, structural evaluation, phenomena modeling, systems analysis, and accident delineation. GCFR studies are focussed on core disruptive testing

  7. Light-Water-Reactor Safety Research Program. Quarterly progress report, January--March 1978

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-05-01

    This progress report summarizes the Argonne National Laboratory work performed during January, February, and March 1978 on water-reactor-safety problems. The following research and development areas are covered: (1) Loss-of-coolant Accident Research: Heat Transfer and Fluid Dynamics; (2) Transient Fuel Response and Fission-product Release Program; (3) Mechanical Properties of Zircaloy Containing Oxygen; and (4) Steam-explosion Studies.

  8. Effect of pH and chloride concentration on the removal of hexavalent chromium in a batch electrocoagulation reactor

    Energy Technology Data Exchange (ETDEWEB)

    Arroyo, M.G. [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Perez-Herranz, V., E-mail: vperez@iqn.upv.es [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Montanes, M.T.; Garcia-Anton, J.; Guinon, J.L. [Departamento de Ingenieria Quimica y Nuclear, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

    2009-09-30

    In this work, the effect of pH and chloride ions concentration on the removal of Cr(VI) from wastewater by batch electrocoagulation using iron plate electrodes has been investigated. The initial solution pH was adjusted with different concentrations of H{sub 2}SO{sub 4}. The presence of chloride ions enhances the anode dissolution due to pitting corrosion. Fe{sup 2+} ions formed during the anode dissolution cause the reduction of Cr(VI) to form Cr(III), which are co-precipitated with Fe{sup 3+} ions at relatively low pH. The reduction degree of Cr(VI) to Cr(III) and the solubility of metal hydroxide species (both chromic and iron hydroxides) depend on pH. At higher concentrations of H{sub 2}SO{sub 4}, the reduction of Cr(VI) to Cr(III) by Fe{sup 2+} ions is preferred, but the coagulation of Fe{sup 3+} and Cr(III) is favoured at the lower H{sub 2}SO{sub 4} concentrations.

  9. Effect of pH and chloride concentration on the removal of hexavalent chromium in a batch electrocoagulation reactor

    International Nuclear Information System (INIS)

    In this work, the effect of pH and chloride ions concentration on the removal of Cr(VI) from wastewater by batch electrocoagulation using iron plate electrodes has been investigated. The initial solution pH was adjusted with different concentrations of H2SO4. The presence of chloride ions enhances the anode dissolution due to pitting corrosion. Fe2+ ions formed during the anode dissolution cause the reduction of Cr(VI) to form Cr(III), which are co-precipitated with Fe3+ ions at relatively low pH. The reduction degree of Cr(VI) to Cr(III) and the solubility of metal hydroxide species (both chromic and iron hydroxides) depend on pH. At higher concentrations of H2SO4, the reduction of Cr(VI) to Cr(III) by Fe2+ ions is preferred, but the coagulation of Fe3+ and Cr(III) is favoured at the lower H2SO4 concentrations.

  10. A pilot plant scale reactor/separator for ethanol from cellulosics. ERIP/DOE quarterly report no. 3 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Dale, M.C.; Moelhman, M.; Butters, R.

    1998-12-01

    The objective of this project is to develop and demonstrate a continuous, low energy process for the conversion of cellulosics to ethanol. This process involves a pretreatment step followed by enzymatic release of sugars and the consecutive simultaneous saccharification/fermentation (SSF) of cellulose (glucans) followed by hemi-cellulose (pentosans) in a multi-stage continuous stirred reactor separator (CSRS). During quarters 3 and 4, we have completed a literature survey on cellulase production, activated one strain of Trichoderma reesei. We continued developing our proprietary Steep Delignification (SD) process for biomass pretreatment. Some problems with fermentations were traces to bad cellulase enzyme. Using commercial cellulase enzymes from Solvay & Genecor, SSF experiments with wheat straw showed 41 g/L ethanol and free xylose of 20 g/L after completion of the fermentation. From corn stover, we noted 36 g/L ethanol production from the cellulose fraction of the biomass, and 4 g/L free xylose at the completion of the SSF. We also began some work with paper mill sludge as a cellulose source, and in some preliminary experiments obtained 23 g/L ethanol during SSF of the sludge. During year 2, a 130 L process scale unit will be operated to demonstrate the process using straw or cornstalks. Co-sponsors of this project include the Indiana Biomass Grants Program, Bio-Process Innovation.

  11. Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO2-water systems

    Science.gov (United States)

    Warr, Oliver; Rochelle, Christopher A.; Masters, Andrew J.; Ballentine, Christopher J.

    2016-01-01

    An experimental approach is presented which can be used to determine partitioning of trace gases within CO2-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magnetic stirrer and high-pressure liquid chromatography pump, respectively.

  12. Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO2-water systems

    International Nuclear Information System (INIS)

    An experimental approach is presented which can be used to determine partitioning of trace gases within CO2-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magnetic stirrer and high-pressure liquid chromatography pump, respectively

  13. Digester performance and microbial community changes in thermophilic and mesophilic sequencing batch reactors fed with the fine sieved fraction of municipal sewage.

    Science.gov (United States)

    Ghasimi, Dara S M; Tao, Yu; de Kreuk, Merle; Abbas, Ben; Zandvoort, Marcel H; van Lier, Jules B

    2015-12-15

    This study investigates the start-up and operation of bench-scale mesophilic (35 °C) and thermophilic (55 °C) anaerobic sequencing batch reactor (SBR) digesters treating the fine sieved fraction (FSF) from raw municipal sewage. FSF was sequestered from raw municipal wastewater, in the Netherlands, using a rotating belt filter equipped with a 350 micron mesh. For the given wastewater, the major component of FSF was toilet paper, which is estimated to be 10-14 kg per year per average person in the western European countries. A seven months adaptation time was allowed for the thermophilic and mesophilic digesters in order to adapt to FSF as the sole substrate with varying dry solids content of 10-25%. Different SBR cycle durations (14, 9 and 2 days) were applied for both temperature conditions to study methane production rates, volatile fatty acids (VFAs) dynamics, lag phases, as well as changes in microbial communities. The prevailing sludge in the two digesters consisted of very different bacterial and archaeal communities, with OP9 lineage and Methanothermobacter being pre-dominant in the thermophilic digester and Bacteroides and Methanosaeta dominating the mesophilic one. Eventually, decreasing the SBR cycle period, thus increasing the FSF load, resulted in improved digester performances, particularly with regard to the thermophilic digester, i.e. shortened lag phases following the batch feedings, and reduced VFA peaks. Over time, the thermophilic digester outperformed the mesophilic one with 15% increased volatile solids (VS) destruction, irrespective to lower species diversity found at high temperature. PMID:25976021

  14. 3D magnetohydrodynamic modelling of a dc low-current plasma arc batch reactor at very high pressure in helium

    International Nuclear Information System (INIS)

    This paper deals with a three-dimensional (3D) time-dependent magnetohydrodynamic (MHD) model under peculiar conditions of very high pressures (from 2 MPa up to 10 MPa) and low currents (2 retro-conversion. However, as a first approach in terms of MHD, the model considers the case for helium as a non-reactive working gas. After a detailed presentation of the model, a reference case has been fully analysed (P = 8 MPa, I = 0.35 A) in terms of physical properties. The results show a bending of the arc and displacement of the anodic arc root towards the top of the reactor, due to the combined effects of convection, gravity and electromagnetic forces. A parametric study on the pressure (2–10 MPa) and current (0.25–0.4 A) was then investigated. The operating pressure does not show an influence on the contraction of the arc but higher pressures involve a higher natural convection in the reactor, driven by the density gradients between the cold and hot gas. (paper)

  15. Competitive adsorption and desorption of strontium and cobalt on acid soils measured in batch and in stirred flow-through reactor

    International Nuclear Information System (INIS)

    Full text of publication follows: In order to investigate adsorption and desorption processes of contaminants, an acid mineral soil (pH = 4.75; organic carbon: 3.8 g.kg-1) and an acid organic soil (pH = 4.65; organic carbon: 65.5 g.kg-1) were tested. Amounts and kinetics of adsorption and desorption of strontium and cobalt were measured in batch and in stirred flow-through reactor. The stirred flow-through method is particularly appropriate to study desorption because an open flow flushes continuously the soil after adsorption. This method is also useful to study reaction kinetics because one can adjust the mean residence time or even close the circuit before desorption stage. The adsorption isotherms of these cations are non-linear for a wide range of concentration (from 10-8 M to 10-1 M). The organic soil presents higher saturating concentrations and retains about 5 times more cobalt than the mineral soil at any concentration. However, the organic soil does not significantly retain more strontium than the mineral soil at low concentrations. Cobalt is more retained than strontium in the organic soil, whereas the adsorption isotherms of strontium and cobalt are identical in the mineral soil (when the concentrations are expressed in mol.L-1 in liquid phase and in mol.kg-1 in solid phase). Adsorption kinetics were measured in batch using 10-4 M solutions. A fast adsorption stage (half-reaction time: 10 mn) was observed, followed by a slow stage (half-reaction time: 10 h). The equilibrium is not reached after 78 days even if adsorption is mainly completed after 2 h. These reaction times seem independent from the cation (strontium or cobalt) and are not affected by the presence of a competing cation (cobalt and strontium together). The same reaction times were observed for higher concentrations (10-3 M) or very low concentrations of radio-cobalt (10-10 M). So, the kinetics seem to be independent from the initial concentration as well. Desorption kinetics were measured

  16. Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO2-water systems.

    Science.gov (United States)

    Warr, Oliver; Rochelle, Christopher A; Masters, Andrew J; Ballentine, Christopher J

    2016-01-01

    An experimental approach is presented which can be used to determine partitioning of trace gases within CO2-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magnetic stirrer and high-pressure liquid chromatography pump, respectively. PMID:26827363

  17. Evaluation of a sequencing batch reactor sewage treatment rig for investigating the fate of radioactively labelled pharmaceuticals: Case study of propranolol.

    Science.gov (United States)

    Popple, T; Williams, J B; May, E; Mills, G A; Oliver, R

    2016-01-01

    Pharmaceuticals are frequently detected in the aquatic environment, and have potentially damaging effects. Effluents from sewage treatment plants (STPs) are major sources of these substances. The use of sequencing batch reactor (SBR) STPs, involving cycling between aerobic and anoxic conditions to promote nitrification and denitrification, is increasing but these have yet to be understood in terms of removal of pharmaceutical residues. This study reports on the development of a laboratory rig to simulate a SBR. The rig was used to investigate the fate of radiolabelled propranolol. This is a commonly prescribed beta blocker, but with unresolved fate in STPs. The SBR rig (4.5 L) was operated on an 8 h batch cycle with settled sewage. Effective treatment was demonstrated, with clearly distinct treatment phases and evidence of nitrogen removal. Radiolabelled (14)C-propranolol was dosed into both single (closed) and continuous (flow-through) simulations over 13 SBR cycles. Radioactivity in CO2 off-gas, biomass and liquid was monitored, along with the characteristics of the sewage. This allowed apparent rate constants and coefficients for biodegradation and solid:water partitioning to be determined. Extrapolation from off-gas radioactivity measurements in the single dose 4-d study suggested that propranolol fell outside the definitions of being readily biodegradable (DegT50 = 9.1 d; 60% biodegradation at 12.0 d). During continuous dosing, 63-72% of propranolol was removed in the rig, but less than 4% of dose recovered as (14)CO2, suggesting that biodegradation was a minor process (Kbiol(M) L kg d(-1) = 22-49) and that adsorption onto solids dominated, giving rise to accumulations within biomass during the 17 d solid retention time in the SBR. Estimations of adsorption isotherm coefficients were different depending on which of three generally accepted denominators representing sorption sites was used (mixed liquor suspended solids, reactor COD or mass of waste

  18. Anaerobic mesophilic co-digestion of sugar-beet processing wastewater and beet-pulp in batch reactors

    Energy Technology Data Exchange (ETDEWEB)

    Alkaya, Emrah; Demirer, Goeksel N. [Department of Environmental Engineering, Middle East Technical University, Inonu Bulvari, 06531 Ankara (Turkey)

    2011-03-15

    In this study, biochemical methane potential (BMP) assay was conducted to investigate the effect of waste mixing and F/M ratio on the co-digestion of wastewater and beet-pulp, in addition to the digestion of the wastes separately. In the studied F/M range (0.51-2.56 g COD/g VSS), observed treatment efficiencies (63.7-87.3% COD removal and 69.6-89.3% VS reduction) were indications of high biodegradability for both wastewater and beet-pulp, which decreased with increasing F/M. It was evident that the extent of biomethanation of wastewater was higher than beet-pulp, owing to the inherent soluble carbohydrates in wastewater. When the co-digestion of the wastes was evaluated, it came up with the result that, major outcome of wastewater addition was to increase methane production rate of beet-pulp, rather than increasing its ultimate biodegradability. Indeed, modeled first-order rate functions indicated that rate constants (k values) differentiated in the ranges between 0.081 and 0.143 day{sup -1} and 0.028-0.050 day{sup -1} respectively for wastewater added and non-added reactors. These results indicated that anaerobic co-digestion of wastewater and beet-pulp is promising since wastewater addition significantly increases the rate of biomethanation of beet-pulp. (author)

  19. 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

  20. Characterization of dissolved organic matter during landfill leachate treatment by sequencing batch reactor, aeration corrosive cell-Fenton, and granular activated carbon in series

    International Nuclear Information System (INIS)

    Landfill leachate is generally characterized as a complex recalcitrant wastewater containing high concentration of dissolved organic matter (DOM). A combination of sequencing batch reactor (SBR) + aeration corrosive cell-Fenton (ACF) + granular activated carbon (GAC) adsorption in series was proposed for the purpose of removing pollutants in the leachate. Fractionation was also performed to investigate the composition changes and characteristics of the leachate DOM in each treatment process. Experimental results showed that organic matter, in terms of chemical oxygen demand (COD), 5-day biological oxygen demand (BOD5), and dissolved organic carbon (DOC), was reduced by 97.2%, 99.1%, and 98.7%, respectively. To differentiate the DOM portions, leachates were separated into five fractions by XAD-8 and XAD-4 resins: hydrophobic acid (HPO-A), hydrophobic neutral (HPO-N), transphilic acid (TPI-A), transphilic neutral (TPI-N), and hydrophilic fraction (HPI). The predominant fraction in the raw leachate was HPO-A (36% of DOC), while the dominant fraction in the final effluent was HPI (53% of DOC). Accordingly, macromolecules were degraded to simpler ones in a relatively narrow range below 1000 Da. Spectral and chromatographic analyses also showed that most humic-like substances in all fractions were effectively removed during the treatments and led to a simultaneous decrease in aromaticity.

  1. On-line analysis of gas-phase composition in the combustion chamber and particle emission characteristics during combustion of wood and waste in a small batch reactor.

    Science.gov (United States)

    Ferge, T; Maguhn, J; Hafner, K; Mühlberger, F; Davidovic, M; Warnecke, R; Zimmermann, R

    2005-03-15

    The emission of particulate matter and gaseous compounds during combustion of wood and refuse-derived fuel in a small batch reactor is investigated by laser mass-spectrometric on-line measurement techniques for gas-phase analysis and simultaneous registration of physical aerosol properties (number size distribution). The gas-phase composition is addressed by a laser-based mass spectrometric method, namely, vacuum-UV single-photon ionization time-of-flight mass spectrometry (VUV-SPI-TOFMS). Particle-size distributions are measured with a scanning mobility particle sizer. Furthermore, a photoelectric aerosol sensor is applied for detection of particle-bound polycyclic aromatic hydrocarbons. The different phases of wood combustion are distinguishable by both the chemical profiles of gas-phase components (e.g., polycyclic aromatic hydrocarbons, PAH) and the particle-size distribution. Furthermore, short disturbances of the combustion process due to air supply shortages are investigated regarding their effect on particle-size distribution and gas-phase composition, respectively. It is shown that the combustion conditions strongly influence the particle-size distribution as well as on the emission of particle-bound polycyclic aromatic hydrocarbons. PMID:15819190

  2. Sludge reduction by direct addition of chlorine dioxide into a sequencing batch reactor under operational mode of repeatedly alternating aeration/non-aeration.

    Science.gov (United States)

    Peng, Hong; Liu, Weiyi; Li, Yuanmei; Xiao, Hong

    2015-01-01

    The effect of direct addition of chlorine dioxide (ClO2) into a repeatedly alternating aeration/non-aeration sequencing batch reactor (SBR) on its sludge reduction and process performance was investigated. The experimental results showed that the sludge reduction efficiency was 32.9% and the observed growth yield (Yobs) of SBR was 0.11 kg VSS (volatile suspended solids) /kg COD (chemical oxygen demand) for 80 days' operation at the optimum ClO2 dosage of 2.0 mg/g TSS (total suspended solids). It was speculated that cell lysis and cryptic growth, uncoupled metabolism and endogenous metabolism were jointly responsible for the sludge reduction in this study. COD, NH3-N, total nitrogen (TN) and total phosphorus (TP) in the effluent increased on average 29.47, 4.44, 1.97 and 0.05 mg/L, respectively. However, the effluent quality still satisfied the first-class B discharge standards for municipal wastewater treatment plants in China. In that case, the sludge maintained fine viability with the specific oxygen uptake rate (SOUR) being 14.47 mg O2/(g VSS·h) and demonstrated good settleability with the sludge volume index (SVI) being 116 mL/g. The extra cost of sludge reduction at the optimum ClO2 dosage was estimated to be 2.24 CNY (or 0.36 dollar)/kg dry sludge. PMID:26524444

  3. Impacts of composite wastewater on a Pampean stream (Argentina) and phytoremediation alternative with Spirodela intermedia Koch (Lemnaceae) growing in batch reactors.

    Science.gov (United States)

    Basílico, Gabriel; de Cabo, Laura; Faggi, Ana

    2013-01-30

    Poultry slaughterhouses are producing increasing amounts of solid organic by-products and waste in Argentina. The objectives of this study are to assess the impacts of wastewater, mainly composed of poultry slaughterhouse effluent, on a Pampean stream and to evaluate the convenience of phytoremediation alternative with Spirodela intermedia. Impacts over La Choza stream (Buenos Aires, Argentina) were evaluated by means of physical and chemical characterization of the water upstream and downstream input. Nutrients and total suspended solids increased downstream of the open channel outlet. A bioassay was performed in order to evaluate the role of S. intermedia in wastewater treatment. Two treatments were performed in batch reactors during 144 h (6 days), with (treatment A) and without (treatment B) the addition of S. intermedia. Water samples were taken at 8, 24, 48, 96 and 144 h after the start of the assay for the determination of ammonium, nitrite, nitrate, soluble reactive phosphorus and total phosphorus. Since removal rates of ammonium and total phosphorus were significantly higher in treatment A than in treatment B and the nitrification process was highly increased in treatment A, then the species could be used for the phytoremediation of composite wastewater. PMID:23246765

  4. Photo-removal of sulfamethoxazole (SMX) by photolytic and photocatalytic processes in a batch reactor under UV-C radiation ({lambda}{sub max} = 254 nm)

    Energy Technology Data Exchange (ETDEWEB)

    Nasuhoglu, Deniz; Yargeau, Viviane [Department of Chemical Engineering, McGill University, 3610 University Street, Montreal, Quebec, H3A 2B2 (Canada); Berk, Dimitrios, E-mail: dimitrios.berk@mcgill.ca [Department of Chemical Engineering, McGill University, 3610 University Street, Montreal, Quebec, H3A 2B2 (Canada)

    2011-02-15

    In this study, photolytic and photocatalytic removal of the antibiotic sulfamethoxazole (SMX) under UVC radiation ({lambda} = 254 nm) was investigated. The light intensity distribution inside the batch photoreactor was characterized by azoxybenzene actinometry. The intensity of incident radiation was found to be a strong function of position inside the reactor. 12 mg L{sup -1} of SMX was completely removed within 10 min of irradiation under UVC photolysis, compared to 30 min under TiO{sub 2} photocatalysis. COD measurement was used as an indication of the mineralization efficiency of both processes and higher COD removal with photocatalysis was shown. After 6 h of reaction with photolysis and photocatalysis, 24% and 87% removal of COD was observed, respectively. Two of the intermediate photo-products were identified as sulfanilic acid and 3-amino-5-methylisoxazole by direct comparison of the HPLC chromatograms of standards to those of treated solutions. Ecotoxicity of treated and untreated solutions of SMX towards Daphnia magna was also investigated. It was found that a 3:1 ratio of sample to standard freshwater and a high initial concentration of 60 mg L{sup -1} of SMX were used to obtain reliable and reproducible results. The photo-products formed during photocatalytic and photolytic processes were shown to be generally more toxic than the parent compound.

  5. Biological treatment of a synthetic dairy wastewater in a sequencing batch biofilm reactor: Statistical modeling using optimization using response surface methodology

    Directory of Open Access Journals (Sweden)

    Zinatizadeh A.A.L.

    2011-01-01

    Full Text Available In this study, the interactive effects of initial chemical oxygen demand (CODin, biomass concentration and aeration time on the performance of a lab-scale sequencing batch biofilm reactor (SBBR treating a synthetic dairy wastewater were investigated. The experiments were conducted based on a central composite design (CCD and analyzed using response surface methodology (RSM. The region of exploration for treatment of the synthetic dairy wastewater was taken as the area enclosed by the influent comical oxygen demand (CODin (1000, 3000 and 5000 mg/l, biomass concentration (3000, 5000 and 7000 mg VSS/l and aeration time (2, 8 and 18 h boundaries. Two dependent parameters were measured or calculated as response. These parameters were total COD removal efficiency and sludge volume index (SVI. The maximum COD removal efficiencies (99.5% were obtained at CODin, biomass concentration and aeration time of 5000 mg COD/l, 7000 mg VSS/l and 18 h, respectively. The present study provides valuable information about interrelations of quality and process parameters at different values of the operating variables.

  6. A start-up of psychrophilic anaerobic sequence batch reactor digesting a 35 % total solids feed of dairy manure and wheat straw.

    Science.gov (United States)

    Saady, Noori M Cata; Massé, Daniel I

    2015-12-01

    Zero liquid discharge is currently an objective in livestock manure management to minimize water pollution. This paper reports the start-up phase of a novel psychrophilic (20 °C) dry anaerobic digestion of dairy manure with bedding fed at 35 % total solids and an organic loading rate of 3.0 g total chemical oxygen demand kg(-1) inoculum day(-1) in anaerobic sequence batch reactors. The specific methane (CH4) yield ranged from 165.4 ± 9.8 to 213.9 ± 13.6 NL CH4 kg(-1) volatile solids (VS) with an overall average of 188 ± 17 NL CH4 kg(-1) VS during 11 successive start-up cycles (231 days) and a maximum CH4 production rate of 10.2 ± 0.6 NL CH4 kg(-1) VS day(-1). The inoculum-to-substrate (VS-based) ratio ranged from 4.06 to 4.47. Although methanogenesis proceeded fairly well the hydrolysis seemed to be the rate limiting step. It is possible start up psychrophilic dry anaerobic digestion of cow feces and wheat straw at feed TS of 35 % within 7-10 successive cycles (147-210 days). PMID:26289773

  7. 厌氧/缺氧SBR反硝化除磷过程的研究%Denitrification and Dephosphatation by Anaerobic/Anoxic Sequencing Batch Reactor

    Institute of Scientific and Technical Information of China (English)

    彭永臻; 李勇智; 王淑莹; 王亚宜

    2004-01-01

    Removal of denitrifying phosphorus was verified in a laboratory anaerobic/anoxic sequencing batch reactor (A/A SBR). The results obtained demonstrated that the anaerobic/anoxic strategy can enrich the growth of denitrifying phosphorus removing bacteria (DPB) and take up phosphate under anoxic condition by using nitrate as the electron acceptor. The phosphorus removal efficiency was higher than 90% and the effluent phosphate concentration was lower than 1 mg·L-1 after the A/A SBR was operated in a steady-state. When the chemical oxygen demand(COD) of influent was lower than 180mg· L-1, the more COD in the influent was, the higher efficiency of phosphorus removal could be attained under anoxic condition. However, simultaneous presence of carbon and nitrate would be detrimental to denitrifying phosphorus removal. Result of influence of sludge retention time (SRT) on denitrifying phosphorus removal suggested that the decrease of SRT caused a washout of DPB and consequently the enhanced biological phosphorus removal decreased with 8 days SRT. When the SRT was restored to 16 days, however, the efficiency of phosphorus removal was higher than 90%.

  8. Long-term effects of ZnO nanoparticles on nitrogen and phosphorus removal, microbial activity and microbial community of a sequencing batch reactor.

    Science.gov (United States)

    Wang, Sen; Gao, Mengchun; She, Zonglian; Zheng, Dong; Jin, Chunji; Guo, Liang; Zhao, Yangguo; Li, Zhiwei; Wang, Xuejiao

    2016-09-01

    The performance, microbial activity, and microbial community of a sequencing batch reactor (SBR) were investigated under the long-term exposure of ZnO nanoparticles (ZnO NPs). Low ZnO NPs concentration (less than 5mg/L) had no obvious effect on the SBR performance, whereas the removals of COD, NH4(+)-N, and phosphorus were affected at 10-60mg/L ZnO NPs. The variation trend of nitrogen and phosphorus removal rate was similar to that of microbial enzymatic activity with the increase of ZnO NPs concentrations. The richness and diversity of microbial community showed obvious variations at different ZnO NPs concentrations. ZnO NPs appeared on the surface and cell interior of activated sludge, and the Zn contents in the effluent and activated sludge increased with the increase of ZnO NPS concentration. The present results provide use information to understand the effect of ZnO NPS on the performance of wastewater biological treatment systems. PMID:27262098

  9. Effects of Bio-sludge Concentration and Dilution Rate on the Efficiency of Sequencing Batch Reactor (SBR System for Textile Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Suntud Sirianuntapiboon

    2012-06-01

    Full Text Available The color removal efficiency of a sequencing batch reactor (SBR system with synthetic textile wastewater (STWW containing 80 mg/L disperse dye increased with the increase of mixed liquor suspended solids (MLSS or solids retention time (SRT. The color removal efficiency was over 98% at an MLSS of 4,000 mg/L and SRT of over 25 days. Also, the color removal efficiency decreased with the increase of dye concentration. Both disperse blue 60 and disperse red 60 repressed the growths and activities of both heterotrophic and denitrifying bacteria, but they did not show any effect on nitrifying bacteria. However, the SBR system did not show any change in color removal efficiency of both disperse red 60 and disperse blue 60. The SBR system showed quite low color, COD and BOD5 removal efficiencies with raw textile wastewater (TWW. But, the system removal efficiencies could be increased by dilution of the TWW and supplementation with glucose. The color removal efficiency of the system with four times diluted-TWW containing 1.875 g/L glucose was 69.6±4.0%. Moreover, contaminated-NaCl in STWW could depress color adsorption yields of living as well as dead bio-sludge.

  10. Comparative study of emerging micropollutants removal by aerobic activated sludge of large laboratory-scale membrane bioreactors and sequencing batch reactors under low-temperature conditions.

    Science.gov (United States)

    Kruglova, Antonina; Kråkström, Matilda; Riska, Mats; Mikola, Anna; Rantanen, Pirjo; Vahala, Riku; Kronberg, Leif

    2016-08-01

    Four emerging micropollutants ibuprofen, diclofenac, estrone (E1) and 17α-ethinylestradiol (EE2) were studied in large laboratory-scale wastewater treatment plants (WWTPs) with high nitrifying activity. Activated sludge (AS) with sludge retention times (SRTs) of 12days and 14days in sequencing batch reactors (SBRs) and 30days, 60days and 90days in membrane bioreactors (MBRs) were examined at 8°C and 12°C. Concentrations of pharmaceuticals and their main metabolites were analysed in liquid phase and solid phase of AS by liquid chromatography-tandem mass spectrometry (LC-MS/MS). A remarkable amount of contaminants were detected in solids of AS, meaning the accumulation of micropollutants in bacterial cells. The biodegradation rate constants (Kbiol) were affected by SRT and temperature. MBR with a 90-day SRT showed the best results of removal. Conventional SBR process was inefficient at 8°C showing Kbiol values lower than 0.5lgSS(-1)d(-1) for studied micropollutants. PMID:27128192

  11. Photo-removal of sulfamethoxazole (SMX) by photolytic and photocatalytic processes in a batch reactor under UV-C radiation (λmax = 254 nm)

    International Nuclear Information System (INIS)

    In this study, photolytic and photocatalytic removal of the antibiotic sulfamethoxazole (SMX) under UVC radiation (λ = 254 nm) was investigated. The light intensity distribution inside the batch photoreactor was characterized by azoxybenzene actinometry. The intensity of incident radiation was found to be a strong function of position inside the reactor. 12 mg L-1 of SMX was completely removed within 10 min of irradiation under UVC photolysis, compared to 30 min under TiO2 photocatalysis. COD measurement was used as an indication of the mineralization efficiency of both processes and higher COD removal with photocatalysis was shown. After 6 h of reaction with photolysis and photocatalysis, 24% and 87% removal of COD was observed, respectively. Two of the intermediate photo-products were identified as sulfanilic acid and 3-amino-5-methylisoxazole by direct comparison of the HPLC chromatograms of standards to those of treated solutions. Ecotoxicity of treated and untreated solutions of SMX towards Daphnia magna was also investigated. It was found that a 3:1 ratio of sample to standard freshwater and a high initial concentration of 60 mg L-1 of SMX were used to obtain reliable and reproducible results. The photo-products formed during photocatalytic and photolytic processes were shown to be generally more toxic than the parent compound.

  12. In core fuel management optimization by varying the equilibrium cycle average flux shape for batch refuelled reactors

    International Nuclear Information System (INIS)

    We suggest a method to overcome this problem of optimization by varying reloading patterns by characterizing each particular reloading pattern by a set of intermediate parameters that are numbers. Plots of the objective function versus the intermediate parameters can be made. When the intermediate parameters represent the reloading patterns in a unique way, the optimum of the objective function can be found by interpolation within such plots and we can find the optimal reloading pattern in terms of intermediate parameters. These have to be transformed backwards to find an optimal reloading pattern. The intermediate parameters are closely related to the time averaged neutron flux shape in the core during an equilibrium cycle. This flux shape is characterized by a set of ratios of the space averaged fluxes in the fuel zones and the space averaged flux in the zone with the fresh fuel elements. An advantage of this choice of intermediate parameters is that it permits analytical calculation of equilibrium cycle fuel densities in the fuel zones for any applied reloading patten characterized by a set of equilibrium cycle average flux ratios and thus, provides analytical calculations of fuel management objective functions. The method is checked for the burnup of one fissile nuclide in a reactor core with the geometry of the PWR at Borssele. For simplicity, neither the conversion of fuel, nor the buildup of fission products were taken into account in this study. Since these phenomena can also be described by the equilibrium cycle average flux ratios, it is likely that this method can be extended to a more realistic method for global in core fuel management optimization. (orig./GL)

  13. Short- and long-term effects of temperature on partial nitrification in a sequencing batch reactor treating domestic wastewater

    International Nuclear Information System (INIS)

    Partial nitrification to nitrite has been frequently obtained at high temperatures, but has proved difficult to achieve at low temperatures when treating low strength domestic wastewater. In this study, the long-term effects of temperature on partial nitrification were investigated by operating a sequencing bath reactor with the use of aeration duration control. The specific ammonia oxidation rate decreased by 1.5 times with the temperature decreasing from 25 to 15 deg. C. However, low temperature did not deteriorate the stable partial nitrification performance. Nitrite accumulation ratio was always above 90%, even slightly higher (above 95%) at low temperatures. The nitrifying sludge accumulated with ammonia-oxidizing bacteria (AOB), but washout of nitrite-oxidizing bacteria (NOB) was used to determine the short-term effects of temperature on ammonia oxidation process. The ammonia oxidation rate depended more sensitively on lower temperatures; correspondingly the temperature coefficient θ was 1.172 from 5 to 20 deg. C, while θ was 1.062 from 20 to 35 deg. C. Moreover, the larger activation energy (111.5 kJ mol-1) was found at lower temperatures of 5-20 deg. C, whereas the smaller value (42.0 kJ mol-1) was observed at higher temperatures of 20-35 deg. C. These findings might be contributed to extend the applicability of the partial nitrification process in wastewater treatment plants operated under cold weather conditions. It is suggested that the selective enrichment of AOB as well as the washout of NOB be obtained by process control before making the biomass slowly adapt to low temperatures for achieving partial nitrification to nitrite at low temperatures.

  14. Effect of an azo dye on the performance of an aerobic granular sludge sequencing batch reactor treating a simulated textile wastewater.

    Science.gov (United States)

    Franca, Rita D G; Vieira, Anabela; Mata, Ana M T; Carvalho, Gilda S; Pinheiro, Helena M; Lourenço, Nídia D

    2015-11-15

    This study analyzed the effect of an azo dye (Acid Red 14) on the performance of an aerobic granular sludge (AGS) sequencing batch reactor (SBR) system operated with 6-h anaerobic-aerobic cycles for the treatment of a synthetic textile wastewater. In this sense, two SBRs inoculated with AGS from a domestic wastewater treatment plant were run in parallel, being one supplied with the dye and the other used as a dye-free control. The AGS successfully adapted to the new hydrodynamic conditions forming smaller, denser granules in both reactors, with optimal sludge volume index values of 19 and 17 mL g(-1) after 5-min and 30-min settling, respectively. As a result, high biomass concentration levels and sludge age values were registered, up to 13 gTSS L(-1) and 40 days, respectively, when deliberate biomass wastage was limited to the sampling needs. Stable dye removal yields above 90% were attained during the anaerobic reaction phase, confirmed by the formation of one of the aromatic amines arising from azo bond reduction. The control of the sludge retention time (SRT) to 15 days triggered a 30% reduction in the biodecolorization yield. However, the increase of the SRT values back to levels above 25 days reverted this effect and also promoted the complete bioconversion of the identified aromatic amine during the aerobic reaction phase. The dye and its breakdown products did not negatively affect the treatment performance, as organic load removal yields higher than 80% were attained in both reactors, up to 77% occurring in the anaerobic phase. These high anaerobic organic removal levels were correlated to an increase of Defluviicoccus-related glycogen accumulating organisms in the biomass. Also, the capacity of the system to deal with shocks of high dye concentration and organic load was successfully demonstrated. Granule breakup after long-term operation only occurred in the dye-free control SBR, suggesting that the azo dye plays an important role in improving granule

  15. QUARTERLY PROGRESS REPORT JANUARY, FEBRUARY, MARCH, 1968 REACTOR FUELS AND MATERIALS DEVELOPMENT PROGRAMS FOR FUELS AND MATERIALS BRANCH OF USAEC DIVISION OF REACTOR DEVELOPMENT AND TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Cadwell, J. J.; de Halas, D. R.; Nightingale, R. E.; Worlton, D. C.

    1968-06-01

    Progress is reported in these areas: nuclear graphite; fuel development for gas-cooled reactors; HTGR graphite studies; nuclear ceramics; fast-reactor nitrides research; non-destructive testing; metallic fuels; basic swelling studies; ATR gas and water loop operation and maintenance; reactor fuels and materials; fast reactor dosimetry and damage analysis; and irradiation damage to reactor metals.

  16. Using continuous UV extinction measurements to monitor and control the aerated phase of sequencing batch reactors; Einsatz der kontinuierlichen UV-Extinktionsmessung fuer die Ueberwachung und Regelung der Belueftungsphase in SBR-Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Nicolet, L.; Rott, U. [Stuttgart Univ. (Germany). Inst. fuer Siedlungswasserbau, Wasserguete- und Abfallwirtschaft; Bardeck, S. [Optek-Danulat GmbH (Germany)

    1999-07-01

    The work describes the measurement of UV extinction - expressed as the spectral absorption coefficient SAC - at a randomly chosen wave length as a technique for monitoring organic load in effluents from sequencing batch reactors (SBR) at municipal and industrial waste water treatment plants. Further described is to what extent the continuous determination of the SAC can be used in practice for the control of the aerated phase of sequencing batch reactors. By this means, process stabilization and optimization can be achieved and operating reliability can be enhanced. (orig.) [German] Inhalt dieses Beitrages ist es, die Messung der UV-Extinktion - ausgedrueckt durch den spektralen Absorptionskoeffizient (SAK) - bei einer frei gewaehlten Wellenlaenge als Verfahren fuer die Ueberwachung der organischen Belastung in den Ablaeufen von SBR-Anlagen (Sequencing-Batch-Reactor) in der kommunalen und industriellen Abwasserreinigung vorzustellen. Weiterhin soll dargestellt werden, in wieweit die kontinuierliche Bestimmung des SAK in der Praxis fuer die Regelung der beluefteten Phase von SBR-Anlagen eingesetzt werden kann. Hiermit kann eine Prozessstabilisierung und -optimierung der Anlagen erreicht sowie die Betriebssicherheit erhoeht werden. (orig.)

  17. Sequencing Batch Reactor (SBR) for the removal of Hg{sup 2+} and Cd{sup 2+} from synthetic petrochemical factory wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Malakahmad, Amirhossein, E-mail: amirhossein@petronas.com.my [Faculty of Energy and Environmental Studies, Islamic Azad University, Science and Research branch, Hesarak, Tehran (Iran, Islamic Republic of); Civil Engineering Department, Universiti Teknologi PETRONAS, Tronoh, Perak (Malaysia); Hasani, Amirhesam [Faculty of Energy and Environmental Studies, Islamic Azad University, Science and Research branch, Hesarak, Tehran (Iran, Islamic Republic of); Eisakhani, Mahdieh [School of Social, Development and the Environment, Universiti Kebangsaan Malaysia, Bangi, Selangor (Malaysia); Isa, Mohamed Hasnain [Civil Engineering Department, Universiti Teknologi PETRONAS, Tronoh, Perak (Malaysia)

    2011-07-15

    Highlights: {yields} We assessed SBR performances to treat synthetic wastewater containing Hg{sup 2+} and Cd{sup 2+}. {yields} SBR was able to remove 76-90% of Hg{sup 2+} and 96-98% of Cd{sup 2+}. {yields} COD removal efficiency and MLVSS was affected by Hg{sup 2+} and Cd{sup 2+} concentrations. {yields} Removal was not only biological process but also by biosorption process of sludge. - Abstract: Petrochemical factories which manufacture vinyl chloride monomer and poly vinyl chloride (PVC) are among the largest industries which produce wastewater contains mercury and cadmium. The objective of this research is to evaluate the performance of a lab-scale Sequencing Batch Reactor (SBR) to treat a synthetic petrochemical wastewater containing mercury and cadmium. After acclimatization of the system which lasted 60 days, the SBR was introduced to mercury and cadmium in low concentrations which then was increased gradually to 9.03 {+-} 0.02 mg/L Hg and 15.52 {+-} 0.02 mg/L Cd until day 110. The SBR performance was assessed by measuring Chemical Oxygen Demand, Total and Volatile Suspended Solids as well as Sludge Volume Index. At maximum concentrations of the heavy metals, the SBR was able to remove 76-90% of Hg{sup 2+} and 96-98% of Cd{sup 2+}. The COD removal efficiency and MLVSS (microorganism population) in the SBR was affected by mercury and cadmium concentrations in influent. Different species of microorganisms such as Rhodospirilium-like bacteria, Gomphonema-like algae, and sulfate reducing-like bacteria were identified in the system. While COD removal efficiency and MLVSS concentration declined during addition of heavy metals, the appreciable performance of SBR in removal of Hg{sup 2+} and Cd{sup 2+} implies that the removal in SBR was not only a biological process, but also by the biosorption process of the sludge.

  18. Long-term exposure of bacterial and protozoan communities to TiO2 nanoparticles in an aerobic-sequencing batch reactor

    Science.gov (United States)

    Supha, Chitpisud; Boonto, Yuphada; Jindakaraked, Manee; Ananpattarachai, Jirapat; Kajitvichyanukul, Puangrat

    2015-06-01

    Titanium dioxide (TiO2) nanopowders at different concentrations (0-50 mg L-1) were injected into an aerobic-sequencing batch reactor (SBR) to investigate the effects of long-term exposure to nanoparticles on bacterial and protozoan communities. The detection of nanoparticles in the bioflocs was analyzed by scanning electron microscopy, transmission electron microscopy, and energy-dispersive x-ray spectroscopy. The SBR wastewater experiments were conducted under the influence of ultraviolet light with photocatalytic TiO2. The intrusion of TiO2 nanoparticles was found both on the surface and inside of the bioflocs. The change of microbial population in terms of mixed liquor-suspended solids and the sludge volume index was monitored. The TiO2 nanoparticles tentatively exerted an adverse effect on the microbial population, causing the reduction of microorganisms (both bacteria and protozoa) in the SBR. The respiration inhibition rate of the bacteria was increased, and the viability of the microbial population was reduced at the high concentration (50 mg L-1) of TiO2. The decreasing number of protozoa in the presence of TiO2 nanoparticles during 20 days of treatment with 0.5 and 1.0 mg L-1 TiO2 is clearly demonstrated. The measured chemical oxygen demand (COD) in the effluent tends to increase with a long-term operation. The increase of COD in the system suggests a decrease in the efficiency of the wastewater treatment plant. However, the SBR can effectively remove the TiO2 nanoparticles (up to 50 mg L-1) from the effluent.

  19. 基于神经网络的SBBR系统建模方法%Modeling based on neural network for sequencing batch biofilm reactor system

    Institute of Scientific and Technical Information of China (English)

    卿晓霞; 梁汉超; 周健; 余建平

    2012-01-01

    It is difficult to build the model of sequencing batch biofilm reactor. This problem has been studied and solved by using the neural network technique. The 7-12-3 back-propagation neural network technique is developed for the system with excluding abnormal data according to pauta criterion,adjusting the network connection weights by training samples,monitoring the training process timely with test samples and the LM algorithm. The model output result being compared with actually measured data,the coefficient of COD is 0.857,ammonia is 0.918,and phosphate is 0.942, meeting the modeling requirement of sewage treatment process.%针对序批式生物膜系统难以构建水质模型的问题,采用神经网络技术进行建模方法研究.根据拉伊达准则剔除异常数据,并用训练样本调整网络连接权值,用检验样本实时动态监控训练过程,用LM算法构建了一个7-12-3结构的BP神经网络模型.将模型输出结果与实测数据进行比较,其相关系数分别为ROOD=0.857,RNH4+-N=0.918,RPO43--P=0.942,能够满足污水处理过程建模的要求.

  20. Site-Specific, Covalent Immobilization of Dehalogenase ST2570 Catalyzed by Formylglycine-Generating Enzymes and Its Application in Batch and Semi-Continuous Flow Reactors.

    Science.gov (United States)

    Jian, Hui; Wang, Yingwu; Bai, Yan; Li, Rong; Gao, Renjun

    2016-01-01

    Formylglycine-generating enzymes can selectively recognize and oxidize cysteine residues within the sulfatase sub motif at the terminus of proteins to form aldehyde-bearing formylglycine (FGly) residues, and are normally used in protein labeling. In this study, an aldehyde tag was introduced to proteins using formylglycine-generating enzymes encoded by a reconstructed set of the pET28a plasmid system for enzyme immobilization. The haloacid dehalogenase ST2570 from Sulfolobus tokodaii was used as a model enzyme. The C-terminal aldehyde-tagged ST2570 (ST2570CQ) exhibited significant enzymological properties, such as new free aldehyde groups, a high level of protein expression and improved enzyme activity. SBA-15 has widely been used as an immobilization support for its large surface and excellent thermal and chemical stability. It was functionalized with amino groups by aminopropyltriethoxysilane. The C-terminal aldehyde-tagged ST2570 was immobilized to SBA-15 by covalent binding. The site-specific immobilization of ST2570 avoided the chemical denaturation that occurs in general covalent immobilization and resulted in better fastening compared to physical adsorption. The site-specific immobilized ST2570 showed 3-fold higher thermal stability, 1.2-fold higher catalytic ability and improved operational stability than free ST2570. The site-specific immobilized ST2570 retained 60% of its original activity after seven cycles of batch operation, and it was superior to the ST2570 immobilized to SBA-15 by physical adsorption, which loses 40% of its original activity when used for the second time. It is remarkable that the site-specific immobilized ST2570 still retained 100% of its original activity after 10 cycles of reuse in the semi-continuous flow reactor. Overall, these results provide support for the industrial-scale production and application of site-specific, covalently immobilized ST2570. PMID:27409601

  1. Site-Specific, Covalent Immobilization of Dehalogenase ST2570 Catalyzed by Formylglycine-Generating Enzymes and Its Application in Batch and Semi-Continuous Flow Reactors

    Directory of Open Access Journals (Sweden)

    Hui Jian

    2016-07-01

    Full Text Available Formylglycine-generating enzymes can selectively recognize and oxidize cysteine residues within the sulfatase sub motif at the terminus of proteins to form aldehyde-bearing formylglycine (FGly residues, and are normally used in protein labeling. In this study, an aldehyde tag was introduced to proteins using formylglycine-generating enzymes encoded by a reconstructed set of the pET28a plasmid system for enzyme immobilization. The haloacid dehalogenase ST2570 from Sulfolobus tokodaii was used as a model enzyme. The C-terminal aldehyde-tagged ST2570 (ST2570CQ exhibited significant enzymological properties, such as new free aldehyde groups, a high level of protein expression and improved enzyme activity. SBA-15 has widely been used as an immobilization support for its large surface and excellent thermal and chemical stability. It was functionalized with amino groups by aminopropyltriethoxysilane. The C-terminal aldehyde-tagged ST2570 was immobilized to SBA-15 by covalent binding. The site-specific immobilization of ST2570 avoided the chemical denaturation that occurs in general covalent immobilization and resulted in better fastening compared to physical adsorption. The site-specific immobilized ST2570 showed 3-fold higher thermal stability, 1.2-fold higher catalytic ability and improved operational stability than free ST2570. The site-specific immobilized ST2570 retained 60% of its original activity after seven cycles of batch operation, and it was superior to the ST2570 immobilized to SBA-15 by physical adsorption, which loses 40% of its original activity when used for the second time. It is remarkable that the site-specific immobilized ST2570 still retained 100% of its original activity after 10 cycles of reuse in the semi-continuous flow reactor. Overall, these results provide support for the industrial-scale production and application of site-specific, covalently immobilized ST2570.

  2. Using a Statistical Model to Examine the Effect of COD: SO42− Ratio, HRT and LA Concentration on Sulfate Reduction in an Anaerobic Sequencing Batch Reactor

    Directory of Open Access Journals (Sweden)

    Rajesh Singh

    2014-11-01

    Full Text Available Taguchi statistical design, an orthogonal array (OA method, was used to study the impact of the COD/SO42− ratio, hydraulic retention time (HRT and linoleic acid (LA concentration on sulfate (SO42− reduction in an anaerobic sequencing batch reactor using glucose as the electron donor. Based on the OA, optimum condition for maximum SO42− reduction was evaluated. Increasing the COD/SO42− ratio and HRT caused decreasing SO42− reduction while increased SO42− reduction was observed with increasing LA concentration (1 g L−1. In control (not fed LA cultures, higher SO42− reduction (87% ± 3% was observed at a low COD/SO42− ratio of 0.8. This indicates that increasing SO42− reduction was observed at increasing SO42− loading rates. In general, results from this study reveal that limiting the substrate concentration with high SO42− levels (low COD/SO42− ratio favors high SO42− removal. Surface plots were used to evaluate the significant interactions between the experimental factors. Accuracy of the model was verified using an analysis of residuals. Optimum conditions for maximum SO42− reduction (97.61% were observed at a COD/SO42− ratio of 0.8 (level 1, 12 h HRT (level 1 together with 1000 mg L−1 LA addition (level 3. In general, the Taguchi OA provided a useful approach for predicting the percent SO42− reduction in inhibited mixed anaerobic cultures within the factor levels investigated.

  3. Effect of pH on biologic degradation of Microcystis aeruginosa by alga-lysing bacteria in sequencing batch biofilm reactors

    Institute of Scientific and Technical Information of China (English)

    Hongjing LI; Mengli HAO; Jingxian LIU; Chen CHEN1; Zhengqiu FAN; Xiangrong WANG

    2012-01-01

    In this paper, the effect of pH on biological degradation of Microcystis aeruginosa by alga-lysing bacteria in laboratory-scale sequencing batch biofilm reactors (SBBRs) was investigated. After 10 d filming with waste activated sludge, the biological film could be formed, and the bioreactors in which laid polyolefin resin filler were used to treat algal culture. By comparing the removal efficiency of chlorophyll a at different aerobic time, the optimum time was determined as 5 h. Under pH 6.5, 7.5, and 8.5 conditions, the removal rates of Microcystis aeruginosa were respectively 75.9%, 83.6%, and 78.3% (in term of chlorophyll a), and that of Chemical Oxygen Demand (CODMn) were 30.6%, 35.8%, and 33.5%. While the removal efficiencies of ammonia nitrogen (NH+ -N) were all 100%. It was observed that the sequence of the removal efficiencies of algae, NH+ -N and organic matter were pH 7.5 〉 pH 8.5 〉 pH 6.5. The results showed that the dominant alga-lysing bacteria in the SBBRs was strain HM-01, which was identified as Bacillus sp. by Polymerase Chain Reaction (PCR) amplification of the 16S rRNA gene, Basic Local Alignment Search Tool (BLAST) analysis, and compar- ison with sequences in the GenBank nucleotide database. The algicidal activated substance which HM-01 strain excreted could withstand high temperature and pressure, also had better hydrophily and stronger polarity.

  4. Performance evaluation of a granular activated carbon-sequencing batch biofilm reactor pilot plant system used in treating real wastewater from recycled paper industry.

    Science.gov (United States)

    Muhamad, Mohd Hafizuddin; Sheikh Abdullah, Siti Rozaimah; Mohamad, Abu Bakar; Rahman, Rakmi Abdul; Kadhum, Abdul Amir Hasan

    2012-01-01

    A pilot scale granular activated carbon-sequencing batch biofilm reactor with a capacity of 2.2 m3 was operated for over three months to evaluate its performance treating real recycled paper industry wastewater under different operational conditions. In this study, dissolved air floatation (DAF) and clarifier effluents were used as influent sources of the pilot plant. During the course of the study, the reactor was able to biodegrade the contaminants in the incoming recycled paper mill wastewater in terms of chemical oxygen demand (COD), adsorbable organic halides (AOX; specifically 2,4-dichlorophenol (2,4-DCP)) and ammoniacal nitrogen (NH3-N) removal efficiencies at varying hydraulic retention times (HRTs) of 1-3 days, aeration rates (ARs) of 2.1-3.4 m3/min and influent feed concentration of 40-950 mg COD/l. Percentages of COD, 2,4-DCP and NH3-N removals increased with increasing HRT, resulting in more than 90% COD, 2,4-DCP and NH3-N removals at HRT values above two days. Degradation of COD, 2,4-DCP and NH3-N were seriously affected by variation of ARs, which resulted in significant decrease of COD, 2,4-DCP and NH3-N removals by decreasing ARs from 3.4 m3/min to 2.1 m3/min, varying in the ranges of 24-80%, 6-96% and 5-42%, respectively. In comparison to the clarifier effluent, the treatment performance of DAF effluent, containing high COD concentration, resulted in a higher COD removal of 82%. The use of diluted DAF effluent did not improve significantly the COD removal. Higher NH3-N removal efficiency of almost 100% was observed during operation after maintenance shutdown compared to normal operation, even at the same HRT of one day due to the higher dissolved oxygen concentrations (1-7 mg/l), while no significant difference in COD removal efficiency was observed. PMID:22720416

  5. Effect and mechanism of carbon sources on phosphorus uptake by microorganisms in sequencing batch reactors with the single-stage oxic process

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    To investigate the chief reason for phosphorus uptake by microorganisms affected by substrates in sequencing batch reactors with the single-stage oxic process,two typical substrates,glucose (R1) and acetate (R2) were used as the sole carbon source,and the performances of phosphorus removal and the changes of intracellular storage were compared. The experimental results showed that the phenomenon of excess phosphorus uptake was observed in two reactors,but bacteria’s capability to take in phosphorus and its intracellular storage were obviously different under the same operational condition. After steady-state operation,total phosphorus (TP) removed per MLVSS in R1 and R2 was 6.7―7.4 and 2.7―3.2 mg/g,respectively. The energy storage of poly-β-hydroxyalkanoates (PHA) was nearly constant in R1 during the whole period,and another aerobic storage of glycogen was accumulated (the max accumulation of glycogen was 3.21 mmol-C/g) when external substrate was consumed,and then was decreased to the initial level. However in R2,PHA and glycogen were both accumulated (2.1 and 0.55 mmol-C/g,respectively) when external substrate was consumed,but they showed different changes after the period of external consumption. Compared to rapid decrease of PHA to the initial level,glycogen continued accumulating to the peak (0.88 mmol-C/g) in 2 h of aeration before decreasing. During the aeration,the accumulations/transformations of internal carbon sources in R1 were higher than those in R2. In addition,obvious TP releases were both observed in R1 and R2 other than PHA and glycogen during the long-term idle period; moreover,the release content of phosphorus in R1 was also higher than that in R2. The researches indicated that different aerobic metabolism of substrate occurred in R1 and R2 due to the different carbon sources in influent,resulting in different types and contents of aerobic storage accumulated/translated in bacteria of R1 and R2. As a result,ATP content provided for

  6. Notifiable events in systems for fission of nuclear fuels - nuclear power plants and research reactors with maximum output exceeding 50 kW of thermal normal rating - in the Federal Republic of Germany. Quarterly report, 2nd quarter of 1996

    International Nuclear Information System (INIS)

    There were 32 notifiable events in nuclear power plants in Germany in the second quarter of 1996. The report lists and characterises all the 32 events notified in the reporting period. The events did not involve any radioactivity release exceeding the maximum permissible limits during this period, so that there were no radiation hazards to the population or the environment. One event was classified at level 1 of the INES event scale (Anomaly). Research reactor operators in Germany reported 5 notifiable events in the reporting period. The report lists and characterises these events. These events did not involve any radioactivity release exceeding the maximum permissible limits during this period, so that there were no radiation hazards to the population or the environment. All events notified were classified into the lowest categories of safety significance of the official event scales (N, or below scale). (orig./DG)

  7. Performance of the auxotrophic Saccharomyces cerevisiae BY4741 as host for the production of IL-1β in aerated fed-batch reactor: role of ACA supplementation, strain viability, and maintenance energy

    Directory of Open Access Journals (Sweden)

    Zueco Jesus

    2009-12-01

    Full Text Available Abstract Background Saccharomyces cerevisiae BY4741 is an auxotrophic commonly used strain. In this work it has been used as host for the expression and secretion of human interleukin-1β (IL1β, using the cell wall protein Pir4 as fusion partner. To achieve high cell density and, consequently, high product yield, BY4741 [PIR4-IL1β] was cultured in an aerated fed-batch reactor, using a defined mineral medium supplemented with casamino acids as ACA (auxotrophy-complementing amino acid source. Also the S. cerevisiae mutant BY4741 Δyca1 [PIR4-IL1β], carrying the deletion of the YCA1 gene coding for a caspase-like protein involved in the apoptotic response, was cultured in aerated fed-batch reactor and compared to the parental strain, to test the effect of this mutation on strain robustness. Viability of the producer strains was examined during the runs and a mathematical model, which took into consideration the viable biomass present in the reactor and the glucose consumption for both growth and maintenance, was developed to describe and explain the time-course evolution of the process for both, the BY4741 parental and the BY4741 Δyca1 mutant strain. Results Our results show that the concentrations of ACA in the feeding solution, corresponding to those routinely used in the literature, are limiting for the growth of S. cerevisiae BY4741 [PIR4-IL1β] in fed-batch reactor. Even in the presence of a proper ACA supplementation, S. cerevisiae BY4741 [PIR4-IL1β] did not achieve a high cell density. The Δyca1 deletion did not have a beneficial effect on the overall performance of the strain, but it had a clear effect on its viability, which was not impaired during fed-batch operations, as shown by the kd value (0.0045 h-1, negligible if compared to that of the parental strain (0.028 h-1. However, independently of their robustness, both the parental and the Δyca1 mutant ceased to grow early during fed-batch runs, both strains using most of the

  8. Microbial dynamics and properties of aerobic granules developed in a laboratory-scale sequencing batch reactor with an intermediate filamentous bulking stage.

    Science.gov (United States)

    Aqeel, H; Basuvaraj, M; Hall, M; Neufeld, J D; Liss, S N

    2016-01-01

    Aerobic granules offer enhanced biological nutrient removal and are compact and dense structures resulting in efficient settling properties. Granule instability, however, is still a challenge as understanding of the drivers of instability is poorly understood. In this study, transient instability of aerobic granules, associated with filamentous outgrowth, was observed in laboratory-scale sequencing batch reactors (SBRs). The transient phase was followed by the formation of stable granules. Loosely bound, dispersed, and pinpoint seed flocs gradually turned into granular flocs within 60 days of SBR operation. In stage 1, the granular flocs were compact in structure and typically 0.2 mm in diameter, with excellent settling properties. Filaments appeared and dominated by stage 2, resulting in poor settleability. By stage 3, the SBRs were selected for larger granules and better settling structures, which included filaments that became enmeshed within the granule, eventually forming structures 2-5 mm in diameter. Corresponding changes in sludge volume index were observed that reflected changes in settleability. The protein-to-polysaccharide ratio in the extracted extracellular polymeric substance (EPS) from stage 1 and stage 3 granules was higher (2.8 and 5.7, respectively), as compared to stage 2 filamentous bulking (1.5). Confocal laser scanning microscopic (CLSM) imaging of the biomass samples, coupled with molecule-specific fluorescent staining, confirmed that protein was predominant in stage 1 and stage 3 granules. During stage 2 bulking, there was a decrease in live cells; dead cells predominated. Denaturing gradient gel electrophoresis (DGGE) fingerprint results indicated a shift in bacterial community composition during granulation, which was confirmed by 16S rRNA gene sequencing. In particular, Janthinobacterium (known denitrifier and producer of antimicrobial pigment) and Auxenochlorella protothecoides (mixotrophic green algae) were predominant during stage

  9. Effect of bio-sludge concentration on the efficiency of sequencing batch reactor (SBR) system to treat wastewater containing Pb2+and Ni2+

    International Nuclear Information System (INIS)

    The removal efficiency of sequencing batch reactor (SBR) system with synthetic industrial estate wastewater (SIEWW) containing Ni2+ or Pb2+ was increased with the increase of mixed liquor suspended solids (MLSS). But, the sludge volume index (SVI) of the system was increased up to higher than 100 mL/g under MLSS of up to 4000 mg/L. Also, the effluent NO3- was decreased with the increase of MLSS. The heavy metals (Ni2+ or Pb2+), BOD5, COD and TKN removal efficiencies of SBR system with SIEWW containing 5 mg/L heavy metal (Ni2+ or Pb2+) under MLSS of 3000 mg/L were 83-85%, 96-97%, 95-96% and 83-94%, respectively. The increase of heavy metal (Ni2+ or Pb2+) concentrations of SIEWW from 5 to 50 mg/L were not significantly effected to both COD and BOD5 removal efficiencies (they were reduced by only 4-5%), but they were strongly effected to both TKN and heavy metals removal efficiencies (they were reduced by 15 and 20-30%, respectively). Both Ni2+ and Pb2+ could repress the growth of both nitrification and denitrification bacteria. And Ni2+ was more effective than Pb2+ to reduce the heavy metals removal efficiency. The SBR system could be applied to treat the industrial estate wastewater (IEWW) containing both Pb2+ and Ni2+ even the heavy metals concentrations was up to 5 mg/L, but the removal efficiency was quite low and excess bio-sludge did not produce. However, the system efficiency could be increased with the increase of BOD5 concentration of the wastewater. The Pb2+, Ni2+, COD, BOD5 and TKN removal efficiencies of the system with IEWW containing 500 mg/L BOD5, 5 mg/L Ni2+ and 5 mg/L Pb2+ under HRT of 3 days were 85.68 ± 0.31%, 87.03 ± 0.21%, 86.0 ± 0.5%, 94.04 ± 0.4% and 90.5 ± 0.9%, respectively. And the effluent SRT, SS and SVI of the system were 44.7 ± 0.6 days, 150 ± 6 mg/L and 100 mL/g, respectively.

  10. Notifiable events in facilities for fission of nuclear fuels in the Federal Republic of Germany. Nuclear power plants and research reactors with a maximum continuous thermal output of more than 50 kW. Second quarterly report 1998

    International Nuclear Information System (INIS)

    The report contains the documentation of notifiable events in the defined reactors recorded over the second quarter of 1998. The documentation is prepared according to the national notification and reporting system prescribed by the relevant law in Germany, and is filed to the national atomic energy supervisory authorities in Germany for documentation in the national record. (orig./CB)

  11. 用改进的序批式生物膜反应器技术处理废水%Treatment of Wastewater with Modified Sequencing Batch Biofilm Reactor Technology

    Institute of Scientific and Technical Information of China (English)

    胡龙兴; 刘宇陆

    2002-01-01

    This paper describes the removal of COD and nitrogen from wastewater with modified sequencing batch biofilm reactor. The strategy of simultaneous feeding and draining was explored. The results show that introduction of a new batch of wastewater and withdrawal of the purified water can be conducted simultaneously with the maximum volumetric exchange rate of about 70 %. Application of this feeding and draining mode leads to the reduction of the cycle time, the increase of the utilization of the reactor volume and the simplification of the reactor structure. The treatment of a synthetic wastewater containing COD and nitrogen was investigated. The operation mode of F(D)-O ( i. e. , simultaneous feeding and draining followed by the aerobic condition) was adopted. It was found that COD was degraded very fast in the initial reaction period of time, then reduced slowly and the ammonia nitrogen and nitrate nitrogen concentrations decreased and increased with time respectively, while the nitrite nitrogen level increased first and then reduced. The relationship between the COD or ammonia nitrogen loading and its removal rate was examined, and the removal of COD, ammonia nitrogen and total nitrogen could exceed 95%, 90% and 80% respectively. The fact that nitrogen could be removed more completely under constant aeration (aerobic condition) of the SBBR operation mode is very interesting and could be explained in several respects.

  12. QUARTERLY PROGRESS REPORT JANUARY, FEBRUARY, MARCH, 1967 REACTOR FUELS AND MATERIALS DEVELOPMENT PROGRAMS FOR FUELS AND MATERIALS BRANCH OF USAEC DEVISION OF REACTOR DEVELOPMENT AND TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Albaugh, F. W.; Bush, S. H.; Cadwell, J. J.; de Halas, D. R.; Worlton, D. C.

    1967-06-01

    Work is reported in the areas of: fast fuels oxides and nitrides; nuclear ceramics; nuclear graphite; basic swelling studies; irradiation damage to reactor metals; ATR gas loop operation and maintenance; metallic fuels; nondestructive testing research; and fast reactor dosimetry and damage analysis.

  13. Batch By Batch Longitudinal Emittance Blowup MD

    CERN Document Server

    Mastoridis, T; Butterworth, A; Jaussi, M; Molendijk, J

    2012-01-01

    The transverse bunch emittance increases significantly at 450 GeV from the time of injection till the ramp due to IBS. By selectively blowing up the longitudinal emittance of the incoming batch at each injection, it should be possible to reduce the transverse emittance growth rates due to IBS. An MD was conducted on April 22nd 2012 to test the feasibility and performance of the batch-by-batch longitudinal emittance blowup. There were three main goals during the MD. First, to test the developed hardware, firmware, and software for the batch-by-batch blowup. Then, to measure the transverse emittance growth rates of blown-up and "witness" batches to quantify any improvement, and finally to test the ALLInjectSequencer class, which deals with the complicated gymnastics of introducing or masking the new batch to various RF loops.

  14. Treatability of cheese whey for single-cell protein production in nonsterile systems: Part I. Optimal condition for lactic acid fermentation using a microaerobic sequencing batch reactor (microaerobic SBR) with immobilized Lactobacillus plantarum TISTR 2265 and microbial communities.

    Science.gov (United States)

    Monkoondee, Sarawut; Kuntiya, Ampin; Chaiyaso, Thanongsak; Leksawasdi, Noppol; Techapun, Charin; Kawee-Ai, Arthitaya; Seesuriyachan, Phisit

    2016-05-18

    Cheese whey contains a high organic content and causes serious problems if it is released into the environment when untreated. This study aimed to investigate the optimum condition of lactic acid production using the microaerobic sequencing batch reactor (microaerobic SBR) in a nonsterile system. The high production of lactic acid was achieved by immobilized Lactobacillus plantarum TISTR 2265 to generate an acidic pH condition below 4.5 and then to support single-cell protein (SCP) production in the second aerobic sequencing batch reactor (aerobic SBR). A hydraulic retention time (HRT) of 4 days and a whey concentration of 80% feeding gave a high lactic acid yield of 12.58 g/L, chemical oxygen demand (COD) removal of 62.38%, and lactose utilization of 61.54%. The microbial communities in the nonsterile system were dominated by members of lactic acid bacteria, and it was shown that the inoculum remained in the system up to 330 days. PMID:26178366

  15. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production, 3rd Quarterly Report

    International Nuclear Information System (INIS)

    The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O and M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed

  16. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production, 3rd Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Mac Donald, Philip Elsworth

    2002-06-01

    The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed.

  17. Advanced Gas Cooled Nuclear Reactor Materials Evaluation and Development Program. Quarterly progress report, April 1, 1977--June 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    The objectives of this program are to evaluate candidate alloys of Very High Temperature Reactor (VHTR) Process Heat and Direct Cycle helium Turbine (DCHT) applications, in terms of the effects of simulated reactor primary coolant (impure helium), high temperatures, and long time exposures on the mechanical properties and structural and surface stability of selected candidate alloys. A second objective is to select and recommend materials for future test facilities and more extensive qualification programs. Work covered in the report includes completion of alloy selection for the screening tests. The alloys selected for potential VHTR Nuclear Process Heat (NPH) applications and for potential DCHT applications are listed. The present status on the simulated reactor helium loop design and construction and the design and construction progress on the testing and analysis facilities and equipment are discussed.

  18. Quarterly technical progress report on water reactor safety programs sponsored by the Nuclear Regulatory Commission's Division of Reactor Safety Research, October--December 1975

    Energy Technology Data Exchange (ETDEWEB)

    1976-05-01

    Light water reactor safety activities performed during October--December 1975 are reported. The blowdown heat transfer tests series of the Semiscale Mod-1 test program was completed. In the LOFT Program, preparations were made for nonnuclear testing. The Thermal Fuels Behavior Program completed a power-cooling-mismatch test and an irradiation effects test on PWR-type fuel rods. Model development and verification efforts of the Reactor Behavior Program included developing new analysis models for the RELAP4 computer code, subroutines for the FRAP-S and FRAP-T codes, and new models for predicting reactor fuel restructuring and zircaloy cladding behavior; an analysis of post-CHF fuel behavior was made using FRAP-T.

  19. Quarterly technical report on water reactor safety programs sponsored by the Nuclear Regulatory Commission's Division of Reactor Safety Research, July--September 1975

    International Nuclear Information System (INIS)

    Light water reactor safety activities performed during July through September 1975 are summarized. The isothermal blowdown test series of the Semiscale Mod-1 test program has provided data for evaluation of break flow phenomena and analyses of piping flow regimes and pump performance. In the LOFT Program, measurement uncertainties were evaluated. The Thermal Fuels Behavior Program completed two power-cooling-mismatch tests on PWR-type fuel rods to investigate critical heat flux characteristics. Model development and verification efforts of the Reactor Behavior Program included development of the SPLEN1 computer code, subroutines for the FRAP-T code, verification of RELAP4, and results of the Halden Recycle Plutonium Experiment

  20. Pro Spring Batch

    CERN Document Server

    Minella, Michael T

    2011-01-01

    Since its release, Spring Framework has transformed virtually every aspect of Java development including web applications, security, aspect-oriented programming, persistence, and messaging. Spring Batch, one of its newer additions, now brings the same familiar Spring idioms to batch processing. Spring Batch addresses the needs of any batch process, from the complex calculations performed in the biggest financial institutions to simple data migrations that occur with many software development projects. Pro Spring Batch is intended to answer three questions: *What? What is batch processing? What

  1. High temperature ceramic membrane reactors for coal liquid upgrading. Quarter report No. 9, September 21, 1991--December 20, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T.

    1992-07-01

    In this project we intend to study a novel process concept, i.e, the use of ceramic membranes reactors in upgrading of coal derived liquids. Membrane reactors have been used in a number of catalytic reaction processes in order to overcome the limitations on conversion imposed by thermodynamic equilibrium. They have, furthermore, the inherent capability for combining reaction and separation in a single step. Thus they offer promise for improving and optimizing yield, selectivity and performance of processes involving complex liquids, as those typically found in coal liquid upgrading. Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sol-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated.

  2. High temperature ceramic membrane reactors for coal liquid upgrading. Quarterly report No. 10, December 21, 1991--March 20, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T.

    1992-07-01

    In this project we will study a novel process concept, i.e., the use of ceramic membrane reactors in upgrading of coal model compounds and coal derived liquids. In general terms, the USC research team is responsible for constructing and operating the membrane reactor apparatus and for testing various inorganic membranes for the upgrading of coal derived asphaltenes and coal model compounds. The USC effort will involve the principal investigator of this project and two graduate research assistants. The ALCOA team is responsible for the preparation of the inorganic membranes, for construction and testing of the ceramic membrane modules, and for measurement of their transport properties. The ALCOA research effort will involve Dr. Paul K. T. Liu, who is the project manager of the ALCOA research team, an engineer and a technician. UNOCAL`s contribution will be limited to overall technical assistance in catalyst preparation and the operation of the laboratory upgrading membrane reactor and for analytical back-up and expertise in oil analysis and materials characterization. UNOCAL is a no-cost contractor but will be involved in all aspects of the project, as deemed appropriate.

  3. High temperature ceramic membrane reactors for coal liquid upgrading. Quarterly report No. 7, March 21, 1991--June 20, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, T.T.

    1992-06-19

    Ceramic membranes are a new class of materials, which have shown promise in a variety of industrial applications. Their mechanical and chemical stability coupled with a wide range of operating temperatures and pressures make them suitable for environments found in coal liquid upgrading. In this project we will evaluate the performance of Sel-Gel alumina membranes in coal liquid upgrading processes under realistic temperature and pressure conditions and investigate the feasibility of using such membranes in a membrane reactor based coal liquid upgrading process. In addition, the development of novel ceramic membranes with enhanced catalytic activity for coal-liquid upgrading applications, such as carbon-coated alumina membranes, will be also investigated.

  4. Nitrogen and phosphorus removal of domestic sewage using luffa cylindrical sponge carrier sequencing batch biofilm reactor%丝瓜络填料SBBR对生活污水脱氮除磷的试验研究

    Institute of Scientific and Technical Information of China (English)

    王营章; 张尚华; 刘志强; 李洁

    2012-01-01

    利用丝瓜络填料序批式生物膜反应器(LS-SBBR)处理生活污水,研究了反应器对生活污水中NH3-N、TN、TP的去除效果以及生物相的变化情况等.试验结果表明:丝瓜络填料SBBR对生活污水中NH3-N、TN、TP的平均去除率分别为90%、78%、88%.说明丝瓜络填料SBBR适用于生活污水的脱氮除磷.%Luffa cylindrical sponge carrier sequencing batch biofilm reactor(LS-SBBR) has been used for treating domestic wastewater. The removing effects of the reactor on NH3-N, TN, TP in domestic water are studied. The results show that the average removal rates of NH3-N,TN and TP reach 90% ,78% and 88% respectively,indicating that the luffa cylindrical sponge carrier SBBR is very suitable for the removal of nitrogen and phosphorus from domestic sewage.

  5. Performance evaluation of the sulfur-redox-reaction-activated up-flow anaerobic sludge blanket and down-flow hanging sponge anaerobic/anoxic sequencing batch reactor system for municipal sewage treatment.

    Science.gov (United States)

    Hatamoto, Masashi; Ohtsuki, Kota; Maharjan, Namita; Ono, Shinya; Dehama, Kazuya; Sakamoto, Kenichi; Takahashi, Masanobu; Yamaguchi, Takashi

    2016-03-01

    A sulfur-redox-reaction-activated up-flow anaerobic sludge blanket (UASB) and down-flow hanging sponge (DHS) system, combined with an anaerobic/anoxic sequencing batch reactor (A2SBR), has been used for municipal sewage treatment for over 2years. The present system achieved a removal rate of 95±14% for BOD, 74±22% for total nitrogen, and 78±25% for total phosphorus, including low water temperature conditions. Sludge conversion rates during the operational period were 0.016 and 0.218g-VSSg-COD-removed(-1) for the UASB, and DHS, respectively, which are similar to a conventional UASB-DHS system, which is not used of sulfur-redox-reaction, for sewage treatment. Using the sulfur-redox reaction made advanced treatment of municipal wastewater with minimal sludge generation possible, even in winter. Furthermore, the occurrence of a unique phenomenon, known as the anaerobic sulfur oxidation reaction, was confirmed in the UASB reactor under the winter season. PMID:26773951

  6. Precipitation of hydroxyapatite at 37 °C in a meso oscillatory flow reactor operated in batch at constant power density

    OpenAIRE

    Castro, Filipa; Ferreira, António; Rocha, F.A.; A.A. Vicente; Teixeira, J. A.

    2013-01-01

    A meso oscillatory flow reactor (OFR) was successfully applied for the precipitation of hydroxyapatite (HAp) nanoparticles. Mixing efficiency of the mesoreactor operated batchwise in a vertical tube was evaluated at constant power density, by monitoring variation of hue values upon mixing both spatially and temporally. The best operating conditions for fast mixing and a more homogeneous reaction medium were verified for f = 0.83 Hz and x0 = 4.5 mm. HAp precipitation was then carried out under...

  7. Batch and flow-through continuous stirred reactor experiments of Sr2+-adsorption onto smectite: influence of pH, concentration and ionic strength

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Strontium-90 (t1/2 = 29.1 years) resulting from the nuclear fission process is one of the main constituents connected with nuclear waste fuel. Concerning the physical properties and sorption behaviour one of the suitable buffer materials used as a backfill in the geological disposal systems for high-level radioactive wastes is smectite. The 2 μm clay fractions of di-octahedral smectite were used for adsorption experiments in batch and flow-through experiments. Flow-through experiments were carried out at different pH (4 and 8) and concentrations (8.00x10-2 mmolSr2+/L, 2.0x10-1 mmolSr2+/L, 3.3x10-1 mmolSr2+/L and 4.1 x10-1 mmol Sr2+/L). Batch experiments were carried out at different ionic strength ([KNO3]=10-2 M and [KNO3]=10-3 M), pH (4 and 8), whereas the concentration ranged between 0.19 mmolSr2+/L and 9.60 mmolSr2+/L. The adsorption strontium rate in flow-through experiments was found higher at pH 4 than at pH 8, where less of 20% amount of strontium was adsorbed on clay surface after 34 hours. This is explained by the surface charge of smectite layers with a permanent negative charge on the basal planes due essentially to isomorphic substitution. Also additional polar sites are conditionally charged by direct protonation of outer edge surfaces. Therefore, more negative sites become available for the strontium ions sorption, as the pH increasing. After adsorption, the clays were submitted to a desorption process. The rate of desorption at pH 4 is initially too fast due to the elevated amount of strontium released by smectite. After 255 min, the strontium amount desorbed is very low and the rate of desorption approached to zero. By contrast at pH 8 the rate of desorption is practically constant, and after 255 min there is a significant amount of strontium released by clay. Due to these different behaviors in different pH conditions, after 10 hours of desorption, the amount of strontium that left the clay in

  8. Recurrent Batch Normalization

    OpenAIRE

    Cooijmans, Tim; Ballas, Nicolas; Laurent, César; Gülçehre, Çağlar; Courville, Aaron

    2016-01-01

    We propose a reparameterization of LSTM that brings the benefits of batch normalization to recurrent neural networks. Whereas previous works only apply batch normalization to the input-to-hidden transformation of RNNs, we demonstrate that it is both possible and beneficial to batch-normalize the hidden-to-hidden transition, thereby reducing internal covariate shift between time steps. We evaluate our proposal on various sequential problems such as sequence classification, language modeling an...

  9. Hydrogenotrophic denitrification process efficiency and the number of denitrifying bacteria (MPN) in the sequencing batch biofilm reactor (SBBR) with platinum and carbon anodes.

    Science.gov (United States)

    Kłodowska, Izabella; Rodziewicz, Joanna; Janczukowicz, Wojciech; Gotkowska-Płachta, Anna; Cydzik-Kwiatkowska, Agnieszka

    2016-04-15

    This work reports on the effect of electric current density and anode material (platinum, carbon) on the concentration of oxidized and mineral forms of nitrogen, on physical parameters (pH, redox potential, electrical conductivity) and the number of denitrifying bacteria in the biofilm (MPN). Experiments were conducted under anaerobic conditions without and with the flow of electric current (with density of 79 mA·m(-2) and 132 mA·m(-2)). Results obtained in the study enabled concluding that increasing density of electric current caused a decreasing concentration of nitrate in the reactor with platinum anode (R1) and carbon anode (R2). Its concentration depended on anode material. The highest hydrogenotrophic denitrification efficiency was achieved in R2 in which the process was aided by inorganic carbon (CO2) that originated from carbon anode oxidation and the electrical conductivity of wastewater increased as a result of the presence of HCO3(-) and CO3(2-) ions. Strong oxidizing properties of the platinum anode (R1) prevented the accumulation of adverse forms of nitrogen, including nitrite and ammonia. The increase in electric current density affected also a lower number of denitrifying bacteria (MPN) in the biofilm in both reactors (R1 and R2). Metal oxides accumulated on the surface of the cathode had a toxic effect upon microorganisms and impaired the production of a hydrogen donor. PMID:26809836

  10. Note: A dual temperature closed loop batch reactor for determining the partitioning of trace gases within CO{sub 2}-water systems

    Energy Technology Data Exchange (ETDEWEB)

    Warr, Oliver, E-mail: oliver.warr@earth.ox.ac.uk; Ballentine, Christopher J. [Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN (United Kingdom); Rochelle, Christopher A. [British Geological Survey, Environmental Science Centre, Nicker Hill, Keyworth, Nottingham NG12 5GG (United Kingdom); Masters, Andrew J. [School of Chemical Engineering and Analytical Science, University of Manchester, Manchester M13 9PL (United Kingdom)

    2016-01-15

    An experimental approach is presented which can be used to determine partitioning of trace gases within CO{sub 2}-water systems. The key advantages of this system are (1) The system can be isolated with no external exchange, making it ideal for experiments with conservative tracers. (2) Both phases can be sampled concurrently to give an accurate composition at each phase at any given time. (3) Use of a lower temperature flow loop outside of the reactor removes contamination and facilitates sampling. (4) Rapid equilibration at given pressure/temperature conditions is significantly aided by stirring and circulating the water phase using a magnetic stirrer and high-pressure liquid chromatography pump, respectively.

  11. Spring batch essentials

    CERN Document Server

    Rao, P Raja Malleswara

    2015-01-01

    If you are a Java developer with basic knowledge of Spring and some experience in the development of enterprise applications, and want to learn about batch application development in detail, then this book is ideal for you. This book will be perfect as your next step towards building simple yet powerful batch applications on a Java-based platform.

  12. Tratamento de água com hidrocarbonetos aromáticos por uso de reator em bateladas sequenciais com inoculo fúngico Treatment of water with aromatic hydrocarbons by use of sequential batch reactor with fungi inoculum

    Directory of Open Access Journals (Sweden)

    Kelly Rodrigues

    2012-06-01

    Full Text Available Um reator em batelada, aerado, com biomassa imobilizada de Aspergillus niger AN400 foi operado durante 10 ciclos de 7 dias para remover benzeno (200 mg.L-1, tolueno (200 mg.L-1 e xileno (50 mg.L-1 - BTX - e de nutrientes de meio basal. O reator era alimentado semanalmente com 4 L do meio e glicose - 1 g.L-1, na Fase I, e 0,5 g.L-1, na Fase II. Os BTX foram detectados até o quarto dia de operação, em todos os ciclos. As melhores eficiências médias de remoção foram na Fase I: 75%de matéria orgânica solúvel, 80% de ortofosfato e 77% de amônia. O reator pode ser uma alternativa viável para tratamento de águas poluídas com BTX, porém há a necessidade de estudar o comportamento do reator durante período de operação mais longo e com ciclos reacionais mais curtos, bem como da identificação dos metabólitos produzidos.A batch reactor with air and immobilized biomass of Aspergillus niger AN400 was operated during 10 cycles of 7 days to remove benzene (200 mg.L-1, toluene (200 mg.L-1, and xylene (50 mg.L-1 - BTX - and nutrients from basal medium. The reactor was weekly fed with 4 L of the medium and glucose - 1 g.L-1 (Phase I and 0.5 g.L-1 (Phase II. The BTX had been detected until the fourth day of operation in all cycles. The best efficiencies of removal had been in Phase I: 75% of soluble organic matter, 80% of orthophosphate and 77% of ammonia. The reactor can be a viable alternative for the contaminated water treatment with BTX. However it has the necessity to study behavior of the reactor during longer period of operation and with shorter reaction cycles, as well as the identification of the produced metabolites.

  13. Notifiable events in facilities for fission of nuclear fuels in the Federal Republic of Germany. Nuclear power plants and research reactors with a maximum continuous thermal output of more than 50 kW. Fourth quarterly report 1996

    International Nuclear Information System (INIS)

    In the 4th quarter 1996, there were 28 notifiable events reported from nuclear power plants in Germany, and 4 from research reactors, all being classified and shown in a tabulated survey. There was no event resulting in release of radioactivity exceeding the regulatory limits, and there were no off-site risks to the population or the environment. All events reported belong to the lowest category N (normal communication of safety significance), and there were non of categories E or S. All reported events belonged to INES category 0 (no or below-scale safety or radiological significance). (orig./DG)

  14. Removal of fermentation inhibitors from alkaline peroxide pretreated and enzymatically hydrolyzed wheat straw: Production of butanol from hydrolysate using Clostridium beijerinckii in batch reactors

    International Nuclear Information System (INIS)

    In these studies, alkaline peroxide pretreatment of wheat straw was investigated. Pretreated wheat straw was hydrolyzed using cellulolytic and xylanolytic enzymes, and the hydrolysate was used to produce butanol using Clostridium beijerinckii P260. The culture produced less than 2.59 g L-1 acetone-butanol-ethanol (ABE) from alkaline peroxide wheat straw hydrolysate (APWSH) that had not been treated to reduce salt concentration (a neutralization product). However, fermentation was successful after inhibitors (salts) were removed from the hydrolysate by electrodialysis. A control glucose fermentation resulted in the production of 21.37 g L-1 ABE, while salt removed APWSH resulted in the production of 22.17 g L-1 ABE. In the two fermentations, reactor productivities were 0.30 and 0.55 g L-1 h-1, respectively. A comparison of use of different substrates (corn fiber, wheat straw) and different pretreatment techniques (dilute sulfuric acid, alkaline peroxide) suggests that generation of inhibitors is substrate and pretreatment specific

  15. Kinetic studies on hydrolysis of urea in a semi-batch reactor at atmospheric pressure for safe use of ammonia in a power plant for flue gas conditioning

    International Nuclear Information System (INIS)

    With growing industrialization in power sector, air is being polluted with a host of substances-most conspicuously with suspended particulate matter emanating from coal-fired thermal power plants. Flue gas conditioning, especially in such power plants, requires in situ generation of ammonia. In the present paper, experiments for kinetic study of hydrolysis of urea have been conducted using a borosil glass reactor, first without stirring followed by with stirring. The study reveals that conversion increases exponentially with an increase in temperature and feed concentration. Furthermore, the effect of stirring speed, temperature and concentration on conversion has been studied. Using collision theory, temperature dependency of forward rate constant has been developed from which activation energy of the reaction and the frequency factors have been calculated. It has been observed that the forward rate constant increases with an increase in temperature. The activation energy and frequency factor with stirring has been found to be 59.85 kJ/mol and 3.9 x 106 min-1 respectively with correlation co-efficient and standard deviation being 0.98% and ±0.1% in that order.

  16. On-line Monitoring for Phosphorus Removal Process and Bacterial Community in Sequencing Batch Reactor%SBR工艺除磷过程与种群结构在线监测

    Institute of Scientific and Technical Information of China (English)

    崔有为; 王淑莹; 李晶

    2009-01-01

    For efficient energy consumption and control of effluent quality, the cycle duration for a sequencing batch reactor (SBR) needs to be adjusted by real-time control according to the characteristics and loading of waste-water. In this study, an on-line information system for phosphorus removal processes was established. Based on the analysis for four systems with different ecological community structures and two operation modes, anaerobic-aerobic process and anaerobic-anaerobic process, the characteristic patterns of oxidation-reduction potential (ORP) and pH were related to phosphorous dynamics in the anaerobic, anoxic and aerobic phases, for determination of the end of phosphorous removal. In the operation mode of anaerobic-aerobic process, the pH profile in the anaerobic phase was used to estimate the relative amount of phosphorous accumulating organisms (PAOs) and glycogen accumulat- ing organisms (GAOs), which is beneficial to early detection of ecology community shifts. The on-line sensor val-ue of pH and ORP may be used as the parameters to adjust the duration for phosphorous removal and community shifts to cope with influent variations and maintain appropriate operation conditions.

  17. Application of response surface methodology (RSM) for optimisation of COD, NH3-N and 2,4-DCP removal from recycled paper wastewater in a pilot-scale granular activated carbon sequencing batch biofilm reactor (GAC-SBBR).

    Science.gov (United States)

    Muhamad, Mohd Hafizuddin; Sheikh Abdullah, Siti Rozaimah; Mohamad, Abu Bakar; Abdul Rahman, Rakmi; Hasan Kadhum, Abdul Amir

    2013-05-30

    In this study, the potential of a pilot-scale granular activated carbon sequencing batch biofilm reactor (GAC-SBBR) for removing chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N) and 2,4-dichlorophenol (2,4-DCP) from recycled paper wastewater was assessed. For this purpose, the response surface methodology (RSM) was employed, using a central composite face-centred design (CCFD), to optimise three of the most important operating variables, i.e., hydraulic retention time (HRT), aeration rate (AR) and influent feed concentration (IFC), in the pilot-scale GAC-SBBR process for recycled paper wastewater treatment. Quadratic models were developed for the response variables, i.e., COD, NH3-N and 2,4-DCP removal, based on the high value (>0.9) of the coefficient of determination (R(2)) obtained from the analysis of variance (ANOVA). The optimal conditions were established at 750 mg COD/L IFC, 3.2 m(3)/min AR and 1 day HRT, corresponding to predicted COD, NH3-N and 2,4-DCP removal percentages of 94.8, 100 and 80.9%, respectively. PMID:23542216

  18. Recovery of resources for advanced life support space applications: effect of retention time on biodegradation of two crop residues in a fed-batch, continuous stirred tank reactor

    Science.gov (United States)

    Strayer, R. F.; Finger, B. W.; Alazraki, M. P.; Cook, K.; Garland, J. L.

    2002-01-01

    Bioreactor retention time is a key process variable that will influence costs that are relevant to long distance space travel or long duration space habitation. However. little is known about the effects of this parameter on the microbiological treatment options that are being proposed for Advanced Life Support (ALS) systems. Two bioreactor studies were designed to examine this variable. In the first one, six retention times ranging from 1.3 to 21.3 days--were run in duplicate, 81 working-volume continuous stirred tank reactors (CSTR) that were fed ALS wheat residues. Ash-free dry weight loss, carbon mineralization, soluble TOC reduction, changes in fiber content (cellulose, hemicellulose, and lignin), bacterial numbers, and mineral recoveries were monitored. At short retention times--1.33 days--biodegradation was poor (total: 16-20%, cellulose - 12%, hemicellulose - 28%) but soluble TOC was decreased by 75-80% and recovery of major crop inorganic nutrients was adequate, except for phosphorus. A high proportion of the total bacteria (ca. 83%) was actively respiring. At the longest retention time tested, 21.3 days, biodegradation was good (total: 55-60%, cellulose ca. 70%, hemicellulose - ca. 55%) and soluble TOC was decreased by 80%. Recovery of major nutrients, except phosphorus, remained adequate. A very low proportion of total bacteria was actively respiring (ca. 16%). The second bioreactor study used potato residue to determine if even shorter retention times could be used (range 0.25-2.0 days). Although overall biodegradation deteriorated, the degradation of soluble TOC continued to be ca. 75%. We conclude that if the goal of ALS bioprocessing is maximal degradation of crop residues, including cellulose, then retention times of 10 days or longer will be needed. If the goal is to provide inorganic nutrients with the smallest volume/weight bioreactor possible, then a retention time of 1 day (or less) is sufficient.

  19. STUDY OF A SEQUENCING BATCH REACTOR TREATING WASTEWATER FROM AN INDUSTRY OF SOFT DRINKS = ESTUDO DE UM REATOR DE LODOS ATIVADOS POR BATELADA PARA O TRATAMENTO DOS EFLUENTES DE UMA INDÚSTRIA DE REFRIGERANTE

    Directory of Open Access Journals (Sweden)

    Rafael Brito de Moura

    2009-01-01

    Full Text Available This work aimed to study a pilot scale sequencing batch reactor in order to enhance its performance treating wastewater from a soft drink industry. Initially, 5 liters of anaerobic sludge from an UASB (Upflow Anaerobic Sludge Blanket reactor were inoculated in the reactor, which was acclimatized to the new conditions during two months. Conducted microscopy examination was developed to observe the microorganisms present in the sludge. After this stage, experimental procedure was divided in six phases with different times of cycles ranging from 8 to 18 hours, divided in aeration, stir and settle. As a result, higher removal percentages of COD were obtained in the 10 hours cycle, reaching an average of 89.8%. The cycle that had higher nitrogen removals was of 14 hours, with mean removal of 78.8%. In all cycles tested, the presence of nitrate in treated effluent was not detected, characterizing biological denitrification. = Esse trabalho teve como objetivo estudar o funcionamento de um reator sequencial por batelada em escala piloto, de forma a aumentar seu rendimento no tratamento de águas residuárias provenientes de uma indústria de refrigerantes. Inicialmente, foram inoculados 5 litros de lodo anaeróbio proveniente de um reator UASB (Upflow Anaerobic Sludge Blanket, sendo este aclimatado para o novo sistema durante dois meses. Foram realizados exames microscópicos do lodo para observar os microrganismos presentes nele. Após essa etapa, o período experimental foi dividido em seis fases de operação com tempos de ciclo variando entre 8 e 18 horas, divididos em aeração, agitação e sedimentação. Como resultado, obteve-se uma maior remoção de DQO para o ciclo de 10 horas, alcançando um percentual médio de 89,8%. O ciclo que apresentou maior remoção de nitrogênio foi o de 14 horas, com remoção de 78,8%. Em todos os ciclos testados, não houve a presença de nitrato no efluente tratado, caracterizando a desnitrificação.

  20. Tratamento de esgoto sanitário utilizando reatores anaeróbios operados em bateladas sequenciais (escala piloto Domestic sewage treatment in pilot-scale anaerobic sequencing batch reactors

    Directory of Open Access Journals (Sweden)

    Arnaldo Sarti

    2006-03-01

    Full Text Available Avaliou-se o desempenho de dois reatores anaeróbios operados em bateladas seqüenciais (1,2 m³ diferenciados pelo tipo de imobilização de biomassa, na forma de suporte inerte e de biomassa granular no tratamento de esgoto sanitário do Campus da USP de São Carlos. O monitoramento ao longo de 70 dias de operação revelou similaridade no comportamento das configurações ensaiadas, que apresentaram eficiências médias de remoção de DQO e sólidos suspensos ao redor de 60% e 75%, respectivamente. Por meio de técnicas de biologia molecular constatou-se diferenças na comunidade bacteriana nos reatores no 35º e 70º dias de operação, indicando que a imobilização de biomassa selecionou populações bacterianas diferentemente. Em relação ao domínio Archaea houve maior similaridade, provavelmente, pelo fato desses microrganismos utilizarem substratos específicos ao final do processo anaeróbio.The performances of two anaerobic sequencing batch reactors (1.2 m³ containing biomass immobilized in inert support and as granular sludge in the treatment of domestic sewage from the Campus of São Carlos-University of São Paulo were evaluated. The experimental phase lasted seventy days. During this period, the reactors presented quite similar performances in respect to COD and total suspended solids removal, achieving average efficiencies of approximately 60% and 75%, respectively. The analysis using molecular biology techniques on biomass samples taken at 35th and 70th showed differences in the bacterial community in the reactors indicating that the type of biomass immobilization selected the populations differently. A higher similarity was found for the Archaea domain probably because these microorganisms utilize specific substrates formed at the end of the anaerobic process.

  1. 40 CFR 63.491 - Batch front-end process vents-recordkeeping requirements.

    Science.gov (United States)

    2010-07-01

    ... reactor for that recipe. (2) A description of, and an emission estimate for, each batch emission episode... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch front-end process vents... § 63.491 Batch front-end process vents—recordkeeping requirements. (a) Group determination records...

  2. Tratamento de águas residuárias de suinocultura em reator anaeróbio operado em batelada sequencial Treatment of swine wastewater in anaerobic sequencing batch reactor

    Directory of Open Access Journals (Sweden)

    Roberto Alves de Oliveira

    2009-12-01

    Full Text Available Neste estudo avaliou-se o desempenho de um reator anaeróbio operado em batelada sequencial, em escala piloto, com volume total de 280 L, no tratamento de águas residuárias de suinocultura. As cargas orgânicas volumétricas aplicadas no reator foram de 4,42; 5,27; 9,33 e 11,79 g DQOtotal (L d-1. As eficiências médias de remoção de DQOtotal, sólidos suspensos totais (SST e sólidos suspensos voláteis (SSV variaram de 56 a 87%. O nitrogênio total Kjedahl (NTK, fósforo total (P-total e magnésio (Mg foram removidos com eficiências médias de 26 a 39%. As produções volumétricas de metano variaram de 0,50 a 0,64 L CH4 (L reator d-1 e não foram observadas diferenças significativas. As relações sólidos voláteis/sólidos totais (SV/ST do lodo de tal reator variaram de 0,74 a 0,58. As maiores concentrações médias de nutrientes no lodo do reator foram para o nitrogênio, fósforo, ferro e cálcio, com valores de 30.610 a 64.400, 1.590 a 9.870, 6.180 a 8.700 e 1.180 a 6.760 mg kg-1 base seca, respectivamente.In the present study, we evaluated an anaerobic sequencing batch reactor, in pilot scale and with a total volume of 280 L, for the treatment of swine wastewater. The organic loading rates applied in such reactor were 4.42; 5.27; 9.33 and 11.79 g CODtotal (L d-1. The average efficiencies of removal of CODtotal total solids suspension (TSS and volatile suspension solids (VSS varied from 56 to 87%. The nutrients total Kjedahl nitrogen (TKN, total phosphorus (total P and Mg were removed with average efficiencies from 26 to 39%. The volumetric methane productions varied from 0.50 to 0.64 L CH4 (L reactor d-1 and did not present significant differences. The VS/TS relations of the aforementioned reactor's sludge varied from 0.74 to 0.58. The highest mean concentrations of nutrients in the reactor sludge were those of nitrogen, phosphorus, iron and calcium, with values from 30.610 to 64.400, 1.590 to 9.870, 6.180 to 8.700 and 1.180 to 6

  3. Following an Optimal Batch Bioreactor Operations Model

    DEFF Research Database (Denmark)

    Ibarra-Junquera, V.; Jørgensen, Sten Bay; Virgen-Ortíz, J.J.;

    2012-01-01

    The problem of following an optimal batch operation model for a bioreactor in the presence of uncertainties is studied. The optimal batch bioreactor operation model (OBBOM) refers to the bioreactor trajectory for nominal cultivation to be optimal. A multiple-variable dynamic optimization of fed-batch...... reactor for biomass production is studied using a differential geometry approach. The maximization problem is solved by handling both the optimal filling policy and substrate concentration in the inlet stream. In order to follow the OBBOM, a master–slave synchronization is used. The OBBOM is considered as...... the master system which includes the optimal cultivation trajectory for the feed flow rate and the substrate concentration. The “real” bioreactor, the one with unknown dynamics and perturbations, is considered as the slave system. Finally, the controller is designed such that the real bioreactor is...

  4. Fourth quarterly report 1976

    International Nuclear Information System (INIS)

    The 4th quarterly report 1976 describes activities which were carried out within the framework of the Fast Breeder project at the Gesellschaft fuer Kernforschung, Karlsruhe, or on its behalf. The sections refer to the following subjects: Fuel rod development; material studies and development; corrosion experiments and coolant analysis; physics experiments; reactor theory; fast breeder safety; instrumentation and signal processing for core control; effects on the environment; sodium technology experiments; thermo- and fluid-dynamic tests in gas; design studies concerning sodium-cooled breeders. (HR)

  5. Batch-to-batch model improvement for cooling crystallization

    OpenAIRE

    Forgione, Marco; Birpoutsoukis, Georgios; Bombois, Xavier; Mesbah, Ali; Daudey, Peter; Van Den Hof, Paul

    2015-01-01

    © 2015 Elsevier Ltd. Two batch-to-batch model update strategies for model-based control of batch cooling crystallization are presented. In Iterative Learning Control, a nominal process model is adjusted by a non-parametric, additive correction term which depends on the difference between the measured output and the model prediction in the previous batch. In Iterative Identification Control, the uncertain model parameters are iteratively estimated using the measured batch data. Due to the diff...

  6. Tratamento de resíduos sólidos de centrais de abastecimento e feiras livres em reator anaeróbio de batelada Treatment of solid waste from supply centers and free markets in batch anaerobic reactor

    Directory of Open Access Journals (Sweden)

    Valderi D. Leite

    2003-08-01

    Full Text Available Em feiras livres e centrais de abastecimento são produzidas quantidades bastante significativas de resíduos sólidos, com características favoráveis ao aproveitamento integral em processo de bioestabilização anaeróbia. O processo de bioestabilização é realizado em reatores anaeróbios de batelada (RAB, com tempo de detenção de sólidos variando de 250 a 300 dias originando, como produtos finais, o biogás, com cerca de 60% de gás metano, além de composto orgânico parcialmente bioestabilizado. Neste trabalho, foram utilizados resíduos sólidos orgânicos tipicamente vegetais, advindos de centrais de abastecimento, feiras livres e lodo de esgoto sanitário. O sistema experimental utilizado era constituído basicamente por um reator anaeróbio de batelada, com capacidade unitária de 2200 litros, além de outros dispositivos complementares. O sistema experimental foi instalado e monitorado na Estação Experimental de Tratamento Biológico de Esgoto Sanitário, situada no Bairro do Tambor, na cidade de Campina Grande, Estado da Paraíba, no período de janeiro a setembro de 2001. No processo de monitoração foram realizadas caracterizações sistemáticas das frações sólidas, líquidas e gasosas. Após análise dos dados, ficou evidenciada a viabilidade desta alternativa de tratamento, restando ser investigada ainda a viabilidade econômica, quando comparada com outras alternativas tecnológicas de tratamento de resíduos sólidos orgânicos.Significant quantity of organic solid waste with favorable characteristics for integral utilization in anaerobic biostabilization is produced in free markets and supply centers. The process is conducted in anaerobic batch reactors (ABR, with detention time of solids varying from 250 to 300 days, producing biogas with about 60% of methane, besides the partially biostabilized organic compost as the final product. In this study, the organic solid waste used was typically of vegetables

  7. NST Quarterly

    International Nuclear Information System (INIS)

    NST Quarterly reports current development in nuclear science and technology in Malaysia. It keeps readers informed on the progress of research, services, application of nuclear science and technology, and other technical news. It highlights MINT activities and also announces coming events

  8. First quarter 2005 sales data

    International Nuclear Information System (INIS)

    This press release brings information on the AREVA group sales data. First quarter 2005 sales for the group were 2,496 millions of euros, up 3,6% year-on-year from 2,41 millions. The change in foreign exchange rates between the two periods show a negative impact of 22 millions euros, which is much lower than in the first quarter of 2004. It analyzes also in more details the situation of the front end, the reactors and service division, the back end division, the transmission and distribution division and the connectors division. (A.L.B.)

  9. Biorreator à membrana em batelada sequencial aplicado ao tratamento de esgoto visando à remoção de nutrientes Membrane sequencing batch reactor for the wastewater treatment aiming the nutrients removal

    Directory of Open Access Journals (Sweden)

    Tiago José Belli

    2012-06-01

    Full Text Available Neste trabalho, avaliou-se o desempenho de um biorreator à membrana em batelada sequencial para a remoção de nutrientes (nitrogênio e fósforo de esgoto sanitário. O reator, construído em escala piloto, foi operado durante 241 dias com tempo total de ciclo de 4 horas, sendo 5 minutos para alimentação, 55 minutos para a fase anóxica e 180 minutos para as fases de aeração e filtração (simultaneamente. Ao longo do monitoramento, foram empregados dois fluxos de filtração: 5,55 e 11,1 L.m-2.h-1, que resultaram nas taxas de troca volumétrica de 5 e 10%, respectivamente. As eficiências médias de remoção de Demanda Química de Oxigênio total, nitrogênio amoniacal e nitrogênio total alcançadas foram de 99, 98 e 96%, respectivamente. Em relação à remoção de fósforo, observou-se inicialmente um baixo rendimento do reator, sendo verificado ao longo do tempo, no entanto, uma tendência de melhora na remoção desse nutriente, atingindo eficiência média de 74% entre os dias 158 e 241. A utilização do fluxo de filtração de 5,55 L.m-2.h-1 proporcionou uma operação estável ao biorreator à membrana em batelada sequencial no que se refere à pressão transmembrana, tendo sido atingido o valor limite de 0,7 bar apenas uma vez em 181 dias de operação, ao passo que, com fluxo de 11,1 L.m-2.h-1, esse limite foi atingido 3 vezes em 55 dias.This study evaluated the performance of a membrane bioreactor sequencing batch, in pilot scale, to remove nutrients (nitrogen and phosphorus from domestic wastewater. The reactor was operated for 241 days with a total cycle time of 4 hours, with 5 minutes for feeding, 55 minutes for the anoxic phase and 180 minutes for the aeration and filtration phases (simultaneously. Throughout the monitoring, two filtration flows were employed: 5.5 and 11.1 (critical flux L.m-2.h-1, which resulted in the volume exchange rates of 5 and 10%, respectively. The removal efficiencies of total Chemical Oxygen

  10. Design and Application of Software Sensors in Batch and Fed-batch Cultivations during Recombinant Protein Expression in Escherichia coli

    OpenAIRE

    Warth, Benedikt

    2008-01-01

    Software sensors are a potent tool to improve biotechnological real time process monitoring and control. In the current project, algorithms for six partly novel, software sensors were established and tested in a microbial reactor system. Eight batch and two fed-batch runs were carried out with a recombinant Escherichia coli to investigate the suitability of the different software sensor models in diverse cultivation stages. Special respect was given to effects on the sensors after recombinant...

  11. Reactors

    International Nuclear Information System (INIS)

    Purpose: To provide a spray cooling structure wherein the steam phase in a bwr reactor vessel can sufficiently be cooled and the upper cap and flanges in the vessel can be cooled rapidly which kept from direct contaction with cold water. Constitution: An apertured shielding is provided in parallel spaced apart from the inner wall surface at the upper portion of a reactor vessel equipped with a spray nozzle, and the lower end of the shielding and the inner wall of the vessel are closed to each other so as to store the cooling water. Upon spray cooling, cooling water jetting out from the nozzle cools the vapor phase in the vessel and then hits against the shielding. Then the cooling water mostly falls as it is, while partially enters through the apertures to the back of the shielding plate, abuts against stoppers and falls down. The stoppers are formed in an inverted L shape so that the spray water may not in direct contaction with the inner wall of the vessel. (Horiuchi, T.)

  12. Shale oil value enhancement research. Quarterly report, March 1 - May 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Bunger, J.W.; Russell, C.P.; Tsai, J.C.H.; Cogswell, D.E.; Mihamou, H.; Wright, A.D.

    1996-12-31

    The overall objective is to develop a new technology for manufacturing valuable marketable products from shale oil. Phase I objectives are to identify desirable components in shale oil, develop separations techniques for those components, identify market needs and to identify plausible products manufacturable from raw shale oil to meet those needs. The quarter`s efforts were concentrated on (a) compound type analysis of shale oil and its extraction products, (b) thermal hydrodealkylation of the >290{degrees}C polar fraction, (c) reaction of pyridinic type compounds to form secondary products, (d) updating SPX economic analysis, and (e) preparation of a business plan for presentation before the Dawnbreaker Commercial Assistance Program. The subcontract on the thermal hydrodealkylation work at the University of Utah ended at May 3 1, 1996. We have obtained valuable information from the batch experiments. The progress on the flow reactor proved somewhat limited because of the restriction of the existing reactor configuration. The liaison with potential industrial partners is continuing. An additional company has reached agreement to proceed with a geochemical testing of shale oil derived products.

  13. Third quarter 2005 sales figures

    International Nuclear Information System (INIS)

    With manufacturing facilities in over 40 countries and a sales network in over 100, AREVA offers customers technological solutions for nuclear power generation and electricity transmission and distribution. The group also provides interconnect systems to the telecommunications, computer and automotive markets. This document presents the sales figures of the group for the third quarter of 2005: sales revenues in the front end division, in the reactor and services division, in the back end division and in the transmission and distribution division

  14. Polling with batch service

    OpenAIRE

    Boxma, O.; Van der Wal; Yechiali, U.

    2008-01-01

    This article considers a batch service polling system. We first study the case in which the server visits the queues cyclically, considering three different service regimes: gated, exhaustive, and globally gated. We subsequently analyze the case (the so-called "Israeli Queue") in which the server first visits the queue with the "oldest" customer. In both cases, queue lengths and waiting times are the main performance measures under consideration.

  15. Modelling of Batch Process Operations

    DEFF Research Database (Denmark)

    Abdul Samad, Noor Asma Fazli; Cameron, Ian; Gani, Rafiqul

    Here a batch cooling crystalliser is modelled and simulated as is a batch distillation system. In the batch crystalliser four operational modes of the crystalliser are considered, namely: initial cooling, nucleation, crystal growth and product removal. A model generation procedure is shown that s...

  16. Collisional mechanisms in D- beam sources for MFE experiments and reactors. Progress report No. 17, covering quarter ending March 31, 1984

    International Nuclear Information System (INIS)

    During this quarter we have tested our scheme to determine the final products and energy released in the charge transfer of H2+ and H3+ in Cs. These reactions occur at low energy in the volume of the LBL (Leung-Ehlers) surface conversion H- source and can yield suprathermal H atoms as well as vibrationally excited H2, both of which can affect the H- production. The scheme utilizes the fact that H atoms, produced by autodissociation of the excited molecular products of charge transfer in the Cs vapor, have a finite (small) probability of capturing a second electron to form H- before leaving the oven

  17. Feasibility Study of Supercritical Light Water Cooled Reactors for Electric Power Production, Progress Report for Work Through September 2003, 2nd Annual/8th Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Philip E. MacDonald

    2003-09-01

    The supercritical water-cooled reactor (SCWR) is one of the six reactor technologies selected for research and development under the Generation-IV program. SCWRs are promising advanced nuclear systems because of their high thermal efficiency (i.e., about 45% vs. about 33% efficiency for current Light Water Reactors, LWRs) and considerable plant simplification. SCWRs are basically LWRs operating at higher pressure and temperatures with a direct once-through cycle. Operation above the critical pressure eliminates coolant boiling, so the coolant remains single-phase throughout the system. Thus the need for recirculation and jet pumps, a pressurizer, steam generators, steam separators and dryers is eliminated. The main mission of the SCWR is generation of low-cost electricity. It is built upon two proven technologies, LWRs, which are the most commonly deployed power generating reactors in the world, and supercritical fossil-fired boilers, a large number of which is also in use around the world.

  18. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production Progress Report for Year 1, Quarter 2 (January - March 2002)

    Energy Technology Data Exchange (ETDEWEB)

    Mac Donald, Philip Elsworth; Buongiorno, Jacopo; Davis, Cliff Bybee; Weaver, Kevan Dean

    2002-03-01

    The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed.

  19. Kinetic study of batch and fed-batch enzymatic saccharification of pretreated substrate and subsequent fermentation to ethanol

    Directory of Open Access Journals (Sweden)

    Gupta Rishi

    2012-03-01

    Full Text Available Abstract Background Enzymatic hydrolysis, the rate limiting step in the process development for biofuel, is always hampered by its low sugar concentration. High solid enzymatic saccharification could solve this problem but has several other drawbacks such as low rate of reaction. In the present study we have attempted to enhance the concentration of sugars in enzymatic hydrolysate of delignified Prosopis juliflora, using a fed-batch enzymatic hydrolysis approach. Results The enzymatic hydrolysis was carried out at elevated solid loading up to 20% (w/v and a comparison kinetics of batch and fed-batch enzymatic hydrolysis was carried out using kinetic regimes. Under batch mode, the actual sugar concentration values at 20% initial substrate consistency were found deviated from the predicted values and the maximum sugar concentration obtained was 80.78 g/L. Fed-batch strategy was implemented to enhance the final sugar concentration to 127 g/L. The batch and fed-batch enzymatic hydrolysates were fermented with Saccharomyces cerevisiae and ethanol production of 34.78 g/L and 52.83 g/L, respectively, were achieved. Furthermore, model simulations showed that higher insoluble solids in the feed resulted in both smaller reactor volume and shorter residence time. Conclusion Fed-batch enzymatic hydrolysis is an efficient procedure for enhancing the sugar concentration in the hydrolysate. Restricting the process to suitable kinetic regimes could result in higher conversion rates.

  20. Quarterly progress report, process development, July--September 1975. Volume I

    Energy Technology Data Exchange (ETDEWEB)

    None,

    1975-01-01

    Four of the six lots of continuously precipitated PETN produced last quarter were formulated into LX-13 and evaluated for firing performance and extrudability. Detonability was improved. Three of the lots fired satisfactorily on the DV blocks; however, extrudability was reduced. Three batches of PETN were formulated this quarter to further examine LX-13 extrudability and detonability.

  1. Bioestabilização anaeróbia de resíduos sólidos orgânicos em reatores de batelada Anaerobic biostabilization of organic solid waste in batch reactors

    Directory of Open Access Journals (Sweden)

    Valderi D. Leite

    2001-04-01

    Full Text Available O processo de bioestabilização anaeróbio pode ser empregado para o tratamento de uma grande variedade de substratos, dentre os quais pode-se destacar os resíduos sólidos orgânicos. Neste trabalho, o processo de bioestabilização anaeróbio foi utilizado, quando do tratamento de resíduos sólidos orgânicos putrescíveis de origem urbana e rural. Os resíduos de origem urbana eram constituídos, basicamente, de restos de fruta, verduras e folhagens, enquanto o rúmen bovino era o resíduo rural utilizado. As proporções de rúmen empregadas foram de 5, 10 e 15% (percentagem em peso.O trabalho foi realizado em um sistema experimental, constituído basicamente por quatro reatores anaeróbios de batelada, com capacidade unitária de 20 L. A eficiência do processo foi determinada tomando-se, como parâmetros avaliativos, os sólidos totais voláteis (STV, a demanda química de oxigênio (DQO e o nitrogênio total Kjedhal (NTK. Salienta-se que este processo de tratamento bioestabiliza os resíduos orgânicos putrescíveis, tornando-os biodisponíveis de aplicação nos solos, além de produzir metano, que pode ser utilizado como fonte alternativa de energia para fins domésticos e industriais. A análise dos dados deste trabalho demonstra que o desempenho do processo de bioestabilização foi função do percentual de rúmen utilizado.The anaerobic biostabilization process can be employed for the treatment of a large variety of substrates, among which the organic solid waste can be cited. In this work, the anaerobic biostabilization process was employed to treat the putrescible organic solid waste of urban and rural origin. The urban origin waste basically consisted of fruits peelings, vegetables and foliage, whereas the rural solid waste was only the bovine rumen. The proportions of rumen used were 5, 10 and 15% (weight basis. The work was carried out on an experimental scale, basically consisting of four anaerobic batch reactors, each with

  2. A general framework for the synthesis and operational design of batch processes

    DEFF Research Database (Denmark)

    Papaeconomou, Eirini; Gani, Rafiqul; Jørgensen, Sten Bay

    2002-01-01

    , which is the sequence of batch operations performed in order to achieve a specific objective. Important features of the methodology are a set of rule-based algorithms that provide the operational model of the units. Such an algorithm is highlighted, together with the associated rules, for the......The objective of this paper is to present a general problem formulation and a general methodology for the synthesis of batch operations and the operational design of individual batch processes, such as mixing, reaction and separation. The general methodology described supplies the batch routes...... operational design of batch reactors. A case study involving the feasible operation of a batch reactor with multiple desirable and undesirable reactions and operational constraints is presented. Application results including verification of the generated operational sequences (alternatives) through dynamic...

  3. A General framework for the Synthesis and Operational Design of Batch Processes

    DEFF Research Database (Denmark)

    , which is the sequence of batch operations performed in order to achieve a specific objective. Important features of the methodology are a set of rule-based algorithms that provide the operational model of the units. Such an algorithm is highlighted, together with the associated rules, for the......The objective of this paper is to present a general problem formulation and a general methodlogy for the synthesis of batch operations and the operational design of individual batch processes, such as mixing, reaction and separation. The general methodology described supplies the batch routes...... operational design of batch reactors. A case study involving the feasible operation of a batch reactor with multiple desirable and undesirable reactions and operational constraints is presented. Application results including verification of the generated operational sequences (alternatives) through dynamic...

  4. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production, Progress Report for Work Through September 2002, 4th Quarterly Report

    Energy Technology Data Exchange (ETDEWEB)

    Mac Donald, Philip Elsworth

    2002-09-01

    The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If no additional moderator is added to the fuel rod lattice, it is possible to attain fast neutron energy spectrum conditions in a supercritical water-cooled reactor (SCWR). This type of core can make use of either fertile or fertile-free fuel and retain a hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity. One can also add moderation and design a thermal spectrum SCWR. The Generation IV Roadmap effort has identified the thermal spectrum SCWR (followed by the fast spectrum SCWR) as one of the advanced concepts that should be developed for future use. Therefore, the work in this NERI project is addressing both types of SCWRs.

  5. More on Combinatorial Batch Codes

    OpenAIRE

    Ruj, Sushmita; Roy, Bimal

    2008-01-01

    Paterson, Stinson and Wei \\cite{PSW} introduced Combinatorial batch codes, which are combinatorial description of Batch code. Batch codes were first presented by Ishai, Kushilevita, Ostrovsky and Sahai \\cite{IKOS} in STOC'04. In this paper we answer some of the questions put forward by Paterson, Stinson and Wei and give some results for the general case $t>1$ which were not studied by the authors.

  6. Reprocessing of spent fuel from AHWR: preliminary batch studies

    International Nuclear Information System (INIS)

    Scheme for the reprocessing of spent fuel from advanced heavy water reactor (AHWR) is under development. Present paper describes the results of some of the preliminary batch studies carried out to collect the data required for conducting counter-current studies. Studies are carried out using simulated solutions and include data on extraction as well as stripping. (author)

  7. Modelling of Batch Process Operations

    DEFF Research Database (Denmark)

    Abdul Samad, Noor Asma Fazli; Cameron, Ian; Gani, Rafiqul

    Here a batch cooling crystalliser is modelled and simulated as is a batch distillation system. In the batch crystalliser four operational modes of the crystalliser are considered, namely: initial cooling, nucleation, crystal growth and product removal. A model generation procedure is shown that...... Freedom (DoF) analysis, choice of variables to satisfy DoF and solution strategy. The batch distillation model for setting up and testing an operating sequence is developed and simulated. This looks at such operating policies as constant reflux ratio or set concentration of specific compound in the...

  8. Notifiable events in facilities for fission of nuclear fuels in the Federal Republic of Germany. Nuclear power plants and research reactors with a maximum continuous thermal output of more than 50 kW. Third quarterly report 1997; Meldepflichtige Ereignisse zur Spaltung von Kernbrennstoffen in der Bundesrepublik Deutschland. Kernkraftwerke und Forschungsreaktoren, deren Hoechstleistung 50 kW thermische Dauerleistung ueberschreitet. Vierteljahresbericht 3. Quartal 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The report presents the survey and the scenarios of events reported from nuclear power plant and research reactors with a rated thermal output above 50 kW, covering the 3rd quarter of 1997. (orig./CB) [Deutsch] Der vorliegende Bericht enthaelt die Uebersicht ueber die meldepflichtigen Ereignisse in Kernkraftwerken und Forschungsreaktoren, deren Hoechstleistung 50 kW thermische Dauerleistung ueberschreitet, fuer das dritte Vierteljahr 1997.

  9. Column and Batch Experiments

    Directory of Open Access Journals (Sweden)

    Jorge L. Gardea-Torresdey

    2005-01-01

    Full Text Available Batch and column experiments were performed to determine the Cu(II binding capacity of silica-immobilized humin biomass. For column studies, 500 bed volumes of a 0.1 mM Cu(II solution were passed through humin packed columns at the flow rates of 1, 1.5, 2, and 3 mL/min. The biopolymer showed an average Cu binding capacity of 12 ± 1.5 mg/g and a Cu recovery of about 96.5 % ± 1.5. The breakthrough points for Cu(II alone were approximately 420, 390, 385, and 300 bed volumes for the flow rates of 1, 1.5, 2 and 3 mL/min, respectively. The interference studies demonstrated that at low concentrations, the hard cations Ca(II and Mg(II did not seem to represent a major interference on Cu(II binding to the humin biopolymer. The selectivity showed by this biopolymer was Cu(II>Ca(II>Mg(II. On the other hand, batch experiments showed that Ca(II + Mg(II at 100mM each reduced the Cu(II binding to 73 %. However, 1000 mM concentrations of Ca(II and Mg(II, separately and in mixture, reduced the Cu(II binding to 47 %, 44 % and 31 %, respectively. The results of this study showed that immobilized humin in a silica matrix could represent an inexpensive bio-source for Cu removal from contaminated water, even in the presence of low concentrations of the hard cations Ca(II and Mg(II.

  10. Survey of reportable events in nuclear power plants and research reactors in the Federal Republic of Germany. Period covered: 4th quarter 1994

    International Nuclear Information System (INIS)

    Nuclear power plants: There were 34 reportable events in the period covered, all 34 events belonged to the lowest category N (normal notification INES scale O); research reactors: There were 5 reportable events, all 5 events belonged to the lowest reportable category N (normal notification, INES scale O). There was no release above limit of radioactivity nor were there any effects on man or environment. (orig.)

  11. Nuclear Energy Research Initiative Program (NERI) Quarterly Progress Report; New Design Equations for Swelling and Irradiation Creep in Generation IV Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Wolfer, W G; Surh, M P; Garner, F A; Chrzan, D C; Schaldach, C; Sturgeon, J B

    2003-02-13

    The objectives of this research project are to significantly extend the theoretical foundation and the modeling of radiation-induced microstructural changes in structural materials used in Generation IV nuclear reactors, and to derive from these microstructure models the constitutive laws for void swelling, irradiation creep and stress-induced swelling, as well as changes in mechanical properties. The need for the proposed research is based on three major developments and advances over the past two decades. First, new experimental discoveries have been made on void swelling and irradiation creep which invalidate previous theoretical models and empirical constitutive laws for swelling and irradiation creep. Second, recent advances in computational methods and power make it now possible to model the complex processes of microstructure evolution over long-term neutron exposures. Third, it is now required that radiation-induced changes in structural materials over extended lifetimes be predicted and incorporated in the design of Generation IV reactors. Our approach to modeling and data analysis is a dual one in accord with both the objectives to simulate the evolution of the microstructure and to develop design equations for macroscopic properties. Validation of the models through data analysis is therefore carried out at both the microscopic and the macroscopic levels. For the microstructure models, we utilize the transmission electron microscopy results from steels irradiated in reactors and from model materials irradiated by neutrons as well as ion bombardments. The macroscopic constitutive laws will be tested and validated by analyzing density data, irradiation creep data, diameter changes of fuel elements, and post-irradiation tensile data. Validation of both microstructure models and macroscopic constitutive laws is a more stringent test of the internal consistency of the underlying science for radiation effects in structural materials for nuclear reactors.

  12. Heterogeneous batch structures in throughput scheduling

    OpenAIRE

    Weeda, P.J.

    1993-01-01

    Recently a few papers appeared on throughput scheduling, dealing with the relationship between batch structure and process structure in discrete batch production, while maximizing time-constrained throughput. Results have been concentrated on the class of homogeneous batch structures, i.e. batch structures with equal batch sizes for each process per cycle. In this paper heterogeneous batch structures are considered. By numerical examples, it is shown that heterogeneous batch structures can ou...

  13. STUDY ON MAXIMUM SPECIFIC SLUDGE ACIVITY OF DIFFERENT ANAEROBIC GRANULAR SLUDGE BY BATCH TESTS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The maximum specific sludge activity of granular sludge from large-scale UASB, IC and Biobed anaerobic reactors were investigated by batch tests. The limitation factors related to maximum specific sludge activity (diffusion, substrate sort, substrate concentration and granular size) were studied. The general principle and procedure for the precise measurement of maximum specific sludge activity were suggested. The potential capacity of loading rate of the IC and Biobed anaerobic reactors were analyzed and compared by use of the batch tests results.

  14. Contribuição para o estudo da influência do dióxido de carbono no processo de biodegradação (reactor fed-batch proporcional)

    OpenAIRE

    Epifâneo, Lisete Calado

    2007-01-01

    O reactor “Fed-batch” Proporcional utiliza o aumento de pressão que se verifica no interior do reactor, provocado pela acumulação do dióxido de carbono produzido no decurso da degradação aeróbia de um composto orgânico, para adicionar substrato ao reactor, sendo a alimentação proporcional à velocidade ou taxa de degradação de substrato. Nestas circunstâncias, e pretendendo-se avaliar da fiabilidade daquele tipo de reactor, era necessário verificar se a reacção biológica era per...

  15. Fundamentals of coal depolymerization: investigation of free radicals in coal depolymerization under SRC-II preheater/reactor conditions. Quarterly report, July 1-September 30, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Petrakis, L; Grandy, D W

    1980-09-01

    The overall objective of the project is to study the fundamentals of coal depolymerization under direct liquefaction preheater/reactor conditions. A uniquely designed and fabricated high pressure/high temperature Electron Spin Resonance (ESR) apparatus is used to monitor the formation and behavior of free radicals, which are generally assumed to be the key factor in coal liquefaction. The main conclusions that have been reached are as follows: the methodology indeed allows the observation of the free radical formation and behavior at conditions relating to direct liquefaction preheater/reactor conditions. Measurements can be made continually three minutes after the heating of the coal slurry is started. Temperatures up to 500/sup 0/C and pressures up to 1800 psi are accessible; the observed changes in the concentration of free radicals due to variations of process variables are a real effect. Concentrations can be determined to +- 40%, but process variable manipulation has produced a 12-fold increase; temperature is the single most significant process variable that affects free radical formation; the next most significant effect is due to the combination of solvent and residence time. Some considerable different chemistry takes place especially in the first half-hour of the reaction when the SRC-II distillate is used as the solvent; this effect is particularly pronounced at 460/sup 0/C; and the conversions obtained in the in situ ESR experiments using SRC-II heavy distillate as the solvent are comparable to the shaken autoclave conversion.

  16. Advanced Proliferation Resistant, Lower Cost, Uranium-Thorium Dioxide Fuels for Light Water Reactors (Progress report for work through June 2002, 12th quarterly report)

    International Nuclear Information System (INIS)

    The overall objective of this NERI project is to evaluate the potential advantages and disadvantages of an optimized thorium-uranium dioxide (ThO2/UO2) fuel design for light water reactors (LWRs). The project is led by the Idaho National Engineering and Environmental Laboratory (INEEL), with the collaboration of three universities, the University of Florida, Massachusetts Institute of Technology (MIT), and Purdue University; Argonne National Laboratory; and all of the Pressurized Water Reactor (PWR) fuel vendors in the United States (Framatome, Siemens, and Westinghouse). In addition, a number of researchers at the Korean Atomic Energy Research Institute and Professor Kwangheon Park at Kyunghee University are active collaborators with Korean Ministry of Science and Technology funding. The project has been organized into five tasks: Task 1 consists of fuel cycle neutronics and economics analysis to determine the economic viability of various ThO2/UO2 fuel designs in PWRs; Task 2 will determine whether or not ThO2/UO2 fuel can be manufactured economically; Task 3 will evaluate the behavior of ThO2/UO2 fuel during normal, off-normal, and accident conditions and compare the results with the results of previous UO2 fuel evaluations and U.S. Nuclear Regulatory Commission (NRC) licensing standards; Task 4 will determine the long-term stability of ThO2/UO2 high-level waste; and Task 5 consists of the Korean work on core design, fuel performance analysis, and xenon diffusivity measurements

  17. A pilot plant scale reactor/separator for ethanol from cellulosics. Quarterly report No. 1 & 2, October 1, 1997--March 30, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Dale, M.C.

    1998-06-01

    The basic objective of this project is to develop and demonstrate a continuous, low energy process for the conversion of cellulosics to ethanol. This process involves a pretreatment step followed by enzymatic release of sugars and the consecutive saccharification/fermentation of cellulose (glucans) followed by hemi-cellulose (glucans) in a multi-stage continuous stirred reactor separator (CSRS). During year 1, pretreatment and bench scale fermentation trials will be performed to demonstrate and develop the process, and during year 2, a 130 L or larger process scale unit will be operated to demonstrate the process using straw or cornstalks. Co-sponsors of this project include the Indiana Biomass Grants Program, Bio-Process Innovation, Xylan Inc as a possible provider of pretreated biomass.

  18. Microalgal TAG production strategies: why batch beats repeated-batch

    OpenAIRE

    Benvenuti, G.; Lamers, P.P.; Breuer, G.; Bosma, R.; Cerar, Ana; Wijffels, R.H.; Barbosa, M. J.

    2016-01-01

    Background For a commercially feasible microalgal triglyceride (TAG) production, high TAG productivities are required. The operational strategy affects TAG productivity but a systematic comparison between different strategies is lacking. For this, physiological responses of Nannochloropsis sp. to nitrogen (N) starvation and N-rich medium replenishment were studied in lab-scale batch and repeated-batch (part of the culture is periodically harvested and N-rich medium is re-supplied) cultivation...

  19. Advanced Proliferation Resistant, Lower Cost, Uranium-Thorium Dioxide Fuels for Light Water Reactors (Progress report for work through June 2002, 12th quarterly report)

    Energy Technology Data Exchange (ETDEWEB)

    Mac Donald, Philip Elsworth

    2002-09-01

    The overall objective of this NERI project is to evaluate the potential advantages and disadvantages of an optimized thorium-uranium dioxide (ThO2/UO2) fuel design for light water reactors (LWRs). The project is led by the Idaho National Engineering and Environmental Laboratory (INEEL), with the collaboration of three universities, the University of Florida, Massachusetts Institute of Technology (MIT), and Purdue University; Argonne National Laboratory; and all of the Pressurized Water Reactor (PWR) fuel vendors in the United States (Framatome, Siemens, and Westinghouse). In addition, a number of researchers at the Korean Atomic Energy Research Institute and Professor Kwangheon Park at Kyunghee University are active collaborators with Korean Ministry of Science and Technology funding. The project has been organized into five tasks: · Task 1 consists of fuel cycle neutronics and economics analysis to determine the economic viability of various ThO2/UO2 fuel designs in PWRs, · Task 2 will determine whether or not ThO2/UO2 fuel can be manufactured economically, · Task 3 will evaluate the behavior of ThO2/UO2 fuel during normal, off-normal, and accident conditions and compare the results with the results of previous UO2 fuel evaluations and U.S. Nuclear Regulatory Commission (NRC) licensing standards, · Task 4 will determine the long-term stability of ThO2/UO2 high-level waste, and · Task 5 consists of the Korean work on core design, fuel performance analysis, and xenon diffusivity measurements.

  20. Data-driven batch schuduling

    Energy Technology Data Exchange (ETDEWEB)

    Bent, John [Los Alamos National Laboratory; Denehy, Tim [GOOGLE; Arpaci - Dusseau, Remzi [UNIV OF WISCONSIN; Livny, Miron [UNIV OF WISCONSIN; Arpaci - Dusseau, Andrea C [NON LANL

    2009-01-01

    In this paper, we develop data-driven strategies for batch computing schedulers. Current CPU-centric batch schedulers ignore the data needs within workloads and execute them by linking them transparently and directly to their needed data. When scheduled on remote computational resources, this elegant solution of direct data access can incur an order of magnitude performance penalty for data-intensive workloads. Adding data-awareness to batch schedulers allows a careful coordination of data and CPU allocation thereby reducing the cost of remote execution. We offer here new techniques by which batch schedulers can become data-driven. Such systems can use our analytical predictive models to select one of the four data-driven scheduling policies that we have created. Through simulation, we demonstrate the accuracy of our predictive models and show how they can reduce time to completion for some workloads by as much as 80%.

  1. Batch compositions for cordierite ceramics

    Science.gov (United States)

    Hickman, David L.

    1994-07-26

    Ceramic products consisting principally of cordierite and a method for making them are provided, the method employing batches comprising a mineral component and a chemical component, the mineral component comprising clay and talc and the chemical component consisting essentially of a combination of the powdered oxides, hydroxides, or hydrous oxides of magnesium, aluminum and silicon. Ceramics made by extrusion and firing of the batches can exhibit low porosity, high strength and low thermal expansion coefficients.

  2. From Fed-batch to Continuous Enzymatic Biodiesel Production

    DEFF Research Database (Denmark)

    Price, Jason Anthony; Nordblad, Mathias; Woodley, John M.;

    2015-01-01

    In this this paper, we use mechanistic modelling to guide the development of acontinuous enzymatic process that is performed as a fed-batch operation. In this workwe use the enzymatic biodiesel process as a case study. A mechanistic model developedin our previous work was used to determine...... measured components (triglycerides, diglycerides, monoglycerides, free fatty acid and fatty acid methyl esters(biodiesel)) much better than using fed-batch data alone given the smaller residuals. We also observe a reduction in the correlation between the parameters.The model was then used to predict that 5...... reactors are required (with a combined residence time of 30 hours) to reach a final biodiesel concentration within 2 % of the95.6 mass % achieved in a fed-batch operation, for 24 hours....

  3. HYDRODYNAMIC MODELS FOR SLURRY BUBBLE COLUMN REACTORS. FINAL TECHNICAL REPORT ALSO INCLUDES THE QUARTERLY TECHNICAL REPORT FOR THE PERIOD 01/01/1997 - 03/31/1997.

    Energy Technology Data Exchange (ETDEWEB)

    DIMITRI GIDASPOW

    1997-08-15

    The objective of this study is to develop a predictive experimentally verified computational fluid dynamic (CFD) three phase model. It predicts the gas, liquid and solid hold-ups (volume fractions) and flow patterns in the industrially important bubble-coalesced (churn-turbulent) regime. The input into the model can be either particulate viscosities as measured with a Brookfield viscometer or effective restitution coefficient for particles. A combination of x-ray and {gamma}-ray densitometers was used to measure solid and liquid volume fractions. There is a fair agreement between the theory and the experiment. A CCD camera was used to measure instantaneous particle velocities. There is a good agreement between the computed time average velocities and the measurements. There is an excellent agreement between the viscosity of 800 {micro}m glass beads obtained from measurement of granular temperature (random kinetic energy of particles) and the measurement using a Brookfield viscometer. A relation between particle Reynolds stresses and granular temperature was found for developed flow. Such measurement and computations gave a restitution coefficient for a methanol catalyst to be about 0.9. A transient, two-dimensional hydrodynamic model for production of methanol from syn-gas in an Air Products/DOE LaPorte slurry bubble column reactor was developed. The model predicts downflow of catalyst at the walls and oscillatory particle and gas flow at the center, with a frequency of about 0.7 Hertz. The computed temperature variation in the rector with heat exchangers was only about 5 K, indicating good thermal management. The computed slurry height, the gas holdup and the rate of methanol production agree with LaPorte's reported data. Unlike the previous models in the literature, this model computes the gas and the particle holdups and the particle rheology. The only adjustable parameter in the model is the effective particle restitution coefficient.

  4. BatchJobs and BatchExperiments: Abstraction Mechanisms for Using R in Batch Environments

    Directory of Open Access Journals (Sweden)

    Bernd Bischl

    2015-03-01

    Full Text Available Empirical analysis of statistical algorithms often demands time-consuming experiments. We present two R packages which greatly simplify working in batch computing environments. The package BatchJobs implements the basic objects and procedures to control any batch cluster from within R. It is structured around cluster versions of the well-known higher order functions Map, Reduce and Filter from functional programming. Computations are performed asynchronously and all job states are persistently stored in a database, which can be queried at any point in time. The second package, BatchExperiments, is tailored for the still very general scenario of analyzing arbitrary algorithms on problem instances. It extends package BatchJobs by letting the user define an array of jobs of the kind apply algorithm A to problem instance P and store results. It is possible to associate statistical designs with parameters of problems and algorithms and therefore to systematically study their influence on the results. The packages main features are: (a Convenient usage: All relevant batch system operations are either handled internally or mapped to simple R functions. (b Portability: Both packages use a clear and well-defined interface to the batch system which makes them applicable in most high-performance computing environments. (c Reproducibility: Every computational part has an associated seed to ensure reproducibility even when the underlying batch system changes. (d Abstraction and good software design: The code layers for algorithms, experiment definitions and execution are cleanly separated and enable the writing of readable and maintainable code.

  5. Kinetics of D-lactic acid production by Sporolactobacillus sp. strain CASD using repeated batch fermentation.

    Science.gov (United States)

    Zhao, Bo; Wang, Limin; Li, Fengsong; Hua, Dongliang; Ma, Cuiqing; Ma, Yanhe; Xu, Ping

    2010-08-01

    D-lactic acid was produced by Sporolactobacillus sp. strain CASD in repeated batch fermentation with one- and two-reactor systems. The strain showed relatively high energy consumption in its growth-related metabolism in comparison with other lactic acid producers. When the fermentation was repeated with 10% (v/v) of previous culture to start a new batch, D-lactic acid production shifted from being cell-maintenance-dependent to cell-growth-dependent. In comparison with the one-reactor system, D-lactic acid production increased approximately 9% in the fourth batch of the two-reactor system. Strain CASD is an efficient D-lactic acid producer with increased growth rate at the early stage of repeated cycles, which explains the strain's physiological adaptation to repeated batch culture and improved performance in the two-reactor fermentation system. From a kinetic point of view, two-reactor fermentation system was shown to be an alternative for conventional one-reactor repeated batch operation. PMID:20374976

  6. Remoção de sulfato de águas residuárias industriais em reator anaeróbio de leito fixo operado em bateladas sequenciais Sulfate removal from industrial wastewaters in fixed film anaerobic sequential batch reactor

    Directory of Open Access Journals (Sweden)

    Arnaldo Sarti

    2008-03-01

    Full Text Available Avaliou-se o potencial de uso reator anaeróbio operado em bateladas seqüenciais com biomassa imobilizada (ASBBR, em escala piloto, no tratamento de água residuária industrial contendo elevadas concentrações de sulfato. O ASBBR, com volume total de 1.2 m³, foi preenchido com carvão mineral como meio suporte para imobilização da biomassa (leito fixo. Foram aplicadas cargas de 0,15; 0,30; 0,65; 1,30 e 1,90 kg SO4-2/ciclo (ou batelada com duração de 48 h, correspondendo, respectivamente, às concentrações de sulfato no afluente de 0,25; 0,50; 1,0; 2,0 e 3,0 gSO4-2.l-1. Utilizou-se etanol como doador de elétrons para a redução do sulfato. O reator foi operado à temperatura ambiente (29±8ºC, tendo sido obtidas eficiências médias na redução de sulfato entre 88 e 92% em 92 ciclos (275 dias. Os resultados obtidos permitem concluir que o uso de reatores ASBBR constitui-se em alternativa eficiente para a remoção de sulfatos de águas residuárias com características semelhantes às utilizadas neste trabalho.The potential use of an anaerobic sequencing batch biofilm reactor (ASBBR in pilot-scale for the treatment of a sulfate-rich industrial wastewater was evaluated. The pilot 1.2 m³ ASBBR reactor was filled with mineral coal for biomass immobilization (fixed film. The sulfate loading rates applied were 0.15; 0.30; 0.65; 1.30 and 1.90 kg SO4-2/cycle (or batch. Each cycle lasted 48 h. The influent concentrations were, respectively, 0.25; 0.50; 1.0; 2.0 and 3.0 gSO4-2.l-1. Ethanol was used as electron donor for sulfate reduction. The reactor operated at ambient temperature (29±8ºC, and the mean efficiencies of sulfate removal were in the range 88 to 92% in the 92 run cycles. The total operating period comprised 275 days. Based on the results obtained in this research, it could be concluded that the ASBBR can be an efficient alternative for the removal of sulfate from other industrial wastewaters with similar characteristics.

  7. Physicochemical Characteristics of Transferon™ Batches

    Directory of Open Access Journals (Sweden)

    Emilio Medina-Rivero

    2016-01-01

    Full Text Available Transferon, a biotherapeutic agent that has been used for the past 2 decades for diseases with an inflammatory component, has been approved by regulatory authorities in Mexico (COFEPRIS for the treatment of patients with herpes infection. The active pharmaceutical ingredient (API of Transferon is based on polydispersion of peptides that have been extracted from lysed human leukocytes by a dialysis process and a subsequent ultrafiltration step to select molecules below 10 kDa. To physicochemically characterize the drug product, we developed chromatographic methods and an SDS-PAGE approach to analyze the composition and the overall variability of Transferon. Reversed-phase chromatographic profiles of peptide populations demonstrated batch-to-batch consistency from 10 representative batches that harbored 4 primary peaks with a relative standard deviation (RSD of less than 7%. Aminogram profiles exhibited 17 proteinogenic amino acids and showed that glycine was the most abundant amino acid, with a relative content of approximately 18%. Further, based on their electrophoretic migration, the peptide populations exhibited a molecular mass of about 10 kDa. Finally, we determined the Transferon fingerprint using a mass spectrometry tool. Because each batch was produced from independent pooled buffy coat samples from healthy donors, supplied by a local blood bank, our results support the consistency of the production of Transferon and reveal its peptide identity with regard to its physicochemical attributes.

  8. NDA BATCH 2002-02

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence Livermore National Laboratory

    2009-12-09

    QC sample results (daily background checks, 20-gram and 100-gram SGS drum checks) were within acceptable criteria established by WIPP's Quality Assurance Objectives for TRU Waste Characterization. Replicate runs were performed on 5 drums with IDs LL85101099TRU, LL85801147TRU, LL85801109TRU, LL85300999TRU and LL85500979TRU. All replicate measurement results are identical at the 95% confidence level as established by WIPP criteria. Note that the batch covered 5 weeks of SGS measurements from 23-Jan-2002 through 22-Feb-2002. Data packet for SGS Batch 2002-02 generated using gamma spectroscopy with the Pu Facility SGS unit is technically reasonable. All QC samples are in compliance with established control limits. The batch data packet has been reviewed for correctness, completeness, consistency and compliance with WIPP's Quality Assurance Objectives and determined to be acceptable. An Expert Review was performed on the data packet between 28-Feb-02 and 09-Jul-02 to check for potential U-235, Np-237 and Am-241 interferences and address drum cases where specific scan segments showed Se gamma ray transmissions for the 136-keV gamma to be below 0.1 %. Two drums in the batch showed Pu-238 at a relative mass ratio more than 2% of all the Pu isotopes.

  9. Simulated Batch Production of Penicillin

    Science.gov (United States)

    Whitaker, A.; Walker, J. D.

    1973-01-01

    Describes a program in applied biology in which the simulation of the production of penicillin in a batch fermentor is used as a teaching technique to give students experience before handling a genuine industrial fermentation process. Details are given for the calculation of minimum production cost. (JR)

  10. Physicochemical Characteristics of Transferon™ Batches

    Science.gov (United States)

    Pérez-Sánchez, Gilberto; Favari, Liliana; Estrada-Parra, Sergio

    2016-01-01

    Transferon, a biotherapeutic agent that has been used for the past 2 decades for diseases with an inflammatory component, has been approved by regulatory authorities in Mexico (COFEPRIS) for the treatment of patients with herpes infection. The active pharmaceutical ingredient (API) of Transferon is based on polydispersion of peptides that have been extracted from lysed human leukocytes by a dialysis process and a subsequent ultrafiltration step to select molecules below 10 kDa. To physicochemically characterize the drug product, we developed chromatographic methods and an SDS-PAGE approach to analyze the composition and the overall variability of Transferon. Reversed-phase chromatographic profiles of peptide populations demonstrated batch-to-batch consistency from 10 representative batches that harbored 4 primary peaks with a relative standard deviation (RSD) of less than 7%. Aminogram profiles exhibited 17 proteinogenic amino acids and showed that glycine was the most abundant amino acid, with a relative content of approximately 18%. Further, based on their electrophoretic migration, the peptide populations exhibited a molecular mass of about 10 kDa. Finally, we determined the Transferon fingerprint using a mass spectrometry tool. Because each batch was produced from independent pooled buffy coat samples from healthy donors, supplied by a local blood bank, our results support the consistency of the production of Transferon and reveal its peptide identity with regard to its physicochemical attributes. PMID:27525277

  11. Aircraft Nuclear Propulsion Project Quarterly Progress Report for Period Ending December 31, 1956

    Energy Technology Data Exchange (ETDEWEB)

    NA, NA [ORNL

    1957-03-12

    This quarterly progress report of the Aircraft Nuclear Propulsion Project at ORNL records the technical progress of research on circulating-fuel reactors and other ANP research at the Laboratory. The report is divided into five major parts: 1) Aircraft Reactor Engineering, 2) Chemistry, and 3) Metallurgy, 4) Heat Transfer and Physical Properties, Radiation Damage, and Fuel Recovery and Reprocessing, and 5) Reactor Shielding.

  12. Batch chemical microreactors: Reversible, in-situ UHV sealing of a microcavity

    DEFF Research Database (Denmark)

    Monkowski, Adam; Johansson, Martin; Nielsen, Jane Hvolbæk; Chorkendorff, Ib; Hansen, Ole

    We propose a new type of microreactor to study heterogeneous catalytic systems. The proposed device operates using a batch reactor scheme, in which catalyst and reactant are introduced in one step and analyzed in a subsequent step. This differs from a flow microreactor in which reaction and...... analysis take place continuously. A batch microreactor could evaluate the products from a very small amount of catalyst possibly...

  13. NGBAuth - Next Generation Batch Authentication for long running batch jobs.

    CERN Document Server

    Juto, Zakarias

    2015-01-01

    This document describes the prototyping of a new solution for the CERN batch authentication of long running jobs. While the job submission requires valid user credentials, these have to be renewed due to long queuing and execution times. Described within is a new system which will guarantee a similar level of security as the old LSFAuth while simplifying the implementation and the overall architecture. The new system is being built on solid, streamlined and tested components (notably OpenSSL) and a priority has been to make it more generic in order to facilitate the evolution of the current system such as for the expected migration from LSF to Condor as backend batch system.

  14. Cinética de Remoción Biológica de Nitratos en Reactores Batch Secuenciados Manejando Dilución y Carga Pesada de Contaminantes

    Directory of Open Access Journals (Sweden)

    Adriana Lizeth Mendoza Ortega

    2010-01-01

    Full Text Available El desarrollo de bio-procesos para eliminar los compuestos nitrogenados de las aguas residuales y la recuperación del metal es importante en la competitiva industria de refinería de metales en términos de proceso, los factores económicos tales como el uso eficiente de los recursos naturales, la baja energía, los procesos intensivos y un mínimo de descarga de aguas residuales vertidas al medio ambiente. Se ha estudiado la eliminación de nitrógeno biológico de aguas residuales de refinación de metales pesados que contienen altas concentraciones de sales inorgánicas tales como los nitratos. En este trabajo, por un lado, en el Método de Dilución, la concentración del afluente fue 5,500 mg / L, y en el efluente la concentración fue de 320 mg /L, de nitrato de sodio, la degradación es de un 94,1818% en reactor discontinuo secuencial con un tiempo de residencia de 5 días. El comportamiento de la cinética es similar al consumo de DBO. La concentración de nitratos en la solución original fue de 120 gr / L de en un volumen de 0,5 L. (sólo el 9,1% del volumen de reactor. Esta se diluyó con 5 litros de lodo de retorno, desde el dispositivo de 3NaNO sedimentación; concentración final, 5,500 mg / L. Por otra parte, en el concepto de carga pesada (sin la dilución de las aguas residuales se presenta una cinética de primer orden, la concentración del afluente es 87,4 gr / L 3NO- y la concentración del efluente es 28,5 gr / L con un tiempo de residencia de 14 días que representa el 67,39% de removido , es decir 3NO-58,9 gr / L , 10,7 veces más alta que en el método de dilución.

  15. Notifiable events in facilities for fission of nuclear fuels in the Federal Republic of Germany. Nuclear power plants and research reactors with a maximum continuous thermal output of more than 50 kW. Fourth quarterly report 1997; Meldepflichtige Ereignisse in Anlagen zur Spaltung von Kernbrennstoffen in der Bundesrepublik Deutschland. Kernkraftwerke und Forschungsreaktoren, deren Hoechstleistung 50 kW thermische Dauerleistung ueberschreitet. 4. Quartal 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-08-01

    The report presents a brief survey of notifiable events in German nuclear power plants and research reactors of the given output category, covering the last quarter of the year 1997. (orig./CB) [Deutsch] Der vorliegende Bericht enthaelt die Uebersicht ueber die meldepflichtigen Ereignisse in Anlagen zur Spaltung von Kernbrennstoffen (Kernkraftwerke und Forschungsreaktoren, deren Hoechstleistung 50 kW thermische Dauerleistung ueberschreitet) der Bundesrepublik Deutschland fuer das vierte Vierteljahr 1997. (orig./AJ)

  16. Performance of biological hydrogen production process from synthesis gas, mass transfer in batch and continuous bioreactors

    International Nuclear Information System (INIS)

    Biological hydrogen production by anaerobic bacterium, rhodospirillum rubrum was studied in batch and continuous bioreactors using synthesis gas(Co) as substrate. The systems were operated at ambient temperature and pressure. Correlations available in the literature were used to estimate the gas-liquid mass transfer coefficients (KLa) in batch reactor. Based on experimental results for the continuous reactor, new correlation was generated. The results showed that the agitation. gas flow rate and dilution rate were greatly influenced the hydrogen production as well as on KLa. It was found that the KLa of continuous bioreactor was 180 times higher than the mass transfer coefficient reported in batch reactor. It can be considered that the estimation of KLa for the continuous bioreactor may be successful for the large-scale biological hydrogen production

  17. Atlantic Richfield Hanford Company process technology and process development. Quarterly report, April 1977--June 1977

    Energy Technology Data Exchange (ETDEWEB)

    1977-08-01

    This quarterly report is the fifth in a series intended to provide information on research and engineering activities being performed to improve the processing of irradiated reactor fuels, the production of plutonium, and the management of resultant chemical wastes.

  18. Atlantic Richfield Hanford Company process technology and process development. Quarterly report, July 1976--September 1976

    Energy Technology Data Exchange (ETDEWEB)

    1976-11-01

    This quarterly report is the second in a series intended to provide information on research and engineering activities being performed to improve the processing of irradiated reactor fuels, the production of plutonium, and the management of resultant chemical wastes.

  19. Process technology and process development. Atlantic Richfield Hanford Company quarterly report, April 1976--June 1976

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, D. C.

    1976-08-01

    This quarterly report is the first in a series intended to provide information on research and engineering activities being performed to improve the processing of irradiated reactor fuels, the production of plutonium, and the management of resultant chemical wastes.

  20. NDA Batch 2002-13

    Energy Technology Data Exchange (ETDEWEB)

    Hollister, R

    2009-09-17

    QC sample results (daily background check drum and 100-gram SGS check drum) were within acceptance criteria established by WIPP's Quality Assurance Objectives for TRU Waste Characterization. Replicate runs were performed on drum LL85501243TRU. Replicate measurement results are identical at the 95% confidence level as established by WIPP criteria. HWM NCAR No. 02-1000168 issued on 17-Oct-2002 regarding a partially dislodged Cd sheet filter on the HPGe coaxial detector. This physical geometry occurred on 01-Oct-2002 and was not corrected until 10-Oct-2002, during which period is inclusive of the present batch run of drums. Per discussions among the Independent Technical Reviewer, Expert Reviewer and the Technical QA Supervisor, as well as in consultation with John Fleissner, Technical Point of Contact from Canberra, the analytical results are technically reliable. All QC standard runs during this period were in control. Data packet for SGS Batch 2002-13 generated using passive gamma-ray spectroscopy with the Pu Facility SGS unit is technically reasonable. All QC samples are in compliance with establiShed control limits. The batch data packet has been reviewed for correctness, completeness, consistency and compliance with WIPP's Quality Assurance Objectives and determined to be acceptable.

  1. Optimal online-list batch scheduling

    OpenAIRE

    Paulus, JJ Jacob Jan; Ye, Deshi; Zhang, G.

    2008-01-01

    We consider the online-list batch scheduling problem. Jobs arrive one by one and have to be assigned upon arrival to a scheduled batch such that the makespan is minimized. Each batch can accommodate up to B jobs. We give a complete classification of the tractability of this online problem.

  2. 间歇结晶过程的分批优化%Batch-to-batch Optimization of Batch Crystallization Processes

    Institute of Scientific and Technical Information of China (English)

    Woranee Paengjuntuek; Paisan Kittisupakorn; Amornchai Arpornwichanop

    2008-01-01

    It is the fact that several process parameters are either unknown or uncertain. Therefore, an optimal control profile calculated with developed process models with respect to such process parameters may not give an optimal performance when implemented to real processes. This study proposes a batch-to-batch optimization strat-egy for the estimation of uncertain kinetic parameters in a batch crystallization process of potassium sulfate produc-tion. The knowledge of a crystal size distribution of the product at the end of batch operation is used in the proposedmethodology. The updated kinetic parameters are applied for determining an optimal operating temperature policy for the next batch run.

  3. Operation of Finnish nuclear power plants. Quarterly report, 2nd quarter 1997

    International Nuclear Information System (INIS)

    Quarterly Reports on the operation of Finnish nuclear power plants describe events and observations relating to nuclear and radiation safety which STUK - Radiation and Nuclear Safety Authority considers safety significant. Safety improvements at the plants are also described. The Report also includes a summary of the radiation safety of plant personnel and of the environment and tabulated data on the plants' production and load factors. The Finnish nuclear power plant units were in power operation in the second quarter of 1997, except for the annual maintenance outages of Olkiluoto plant units and the Midsummer outage at Olkiluoto 2 due to reduced demand for electricity. There were also brief interruptions in power operation at the Olkiluoto plant units due to three reactor scrams. All plant units are undergoing long-term test operation at upgraded reactor power level which has been approved by STUK The load factor average of all plant units was 88.7 %. One event in the second quarter of 1997 was classified level 1 on the INES. The event in question was a scram at Olkiluoto 1 which was caused by erroneous opening of switches. Other events in this quarter were level 0. Occupational doses and radioactive releases off-site were below authorized limits. Radioactive substances were measurable in samples collected around the plants in such quantities only as have no bearing on the radiation exposure of the population. (orig.)

  4. THE EFFECT OF THE ADDITION OF INVERT SUGAR ON THE PRODUCTION OF CEPHALOSPORIN C IN A FED-BATCH BIOREACTOR

    Directory of Open Access Journals (Sweden)

    A.S. Silva

    1998-12-01

    Full Text Available Cephalosporin C, a b -lactam antibiotic, is the starting molecule for industrial production of semi-synthetic cephalosporins. The bioprocess for its production is carried out in batch stirred and aerated tank reactors utilizing strains of the filamentous fungus Cephalosporium acremonium. In this work a comparison was made between the processes of production of cephalosporin C in a conventional batch bioreactor, with synthetic medium containing glucose and sucrose, and in a fed-batch reactor at several flowrates of supplementary medium containing invert sucrose. In general, the fed-batch process was shown to be more efficient than the conventional batch one, and the process in which the lowest supplementation flowrate was used presented an antibiotic production significantly higher than those obtained under the other conditions.

  5. Batch estimation of statistical errors in the Monte Carlo calculation of local powers

    International Nuclear Information System (INIS)

    Highlights: → Batch methodology performs well on the practical grounds. → The sample variance without autocorrelation terms is utterly unacceptable. → Non-overlapping and overlapping batch means perform better than standardized time series. → Overlapping batch means can be improved based on autocovariance bias correction without the cost of instability. - Abstract: Batch methodology is among the techniques for computing the standard deviation of sample mean and is applicable to any output series from stationary iteration cycles. In the present article, three forms of the methodology are investigated: non-overlapping batch means (NBM), which dates back to , overlapping batch means (OBM) by , and standardized time series (STS) by . In particular, they are applied to the MC calculation of local powers of a pressurized water reactor. The numerical results reveal that the performance of NBM is equivalent to that of OBM, whereas STS performs poorly for small batch sizes. It is also shown that OBM can be improved based on the method of autocovariance bias correction. For a computational condition leading to 0.5-1.5% statistical errors, the improved OBM for a batch size of 10% of the stationary iteration cycle length yields 88-103% of the reference value of standard deviation at tally cells where the sample standard deviation yields 22-36% of the same reference value.

  6. Tratamento de esgoto sanitário em reator híbrido em bateladas sequenciais: eficiência e estabilidade na remoção de matéria orgânica e nutrientes (N, P Sewage treatment in a sequencing batch hybrid reactor: efficiency and stability in organic matter and nutrient (N, P removal

    Directory of Open Access Journals (Sweden)

    Luiz Gonzaga Lamego Neto

    2011-12-01

    Full Text Available Este trabalho apresenta os resultados de estudo sobre o comportamento de um reator híbrido, operado em bateladas sequenciais, na remoção conjunta de matéria carbonácea, nitrogênio e fósforo de esgoto sanitário. Operado em ciclos de 8 horas de duração, o reator possuía em seu interior um suporte fixo com rede de nylon. Foram testadas cargas compreendidas entre 0,39 e 1,35 kgDQO.m-3.dia-1, 42 e 60 gN-NH4-.m-3.dia e 51 e 70 gP-PO4-.m-3.dia. O reator funcionou como um sistema estável e apresentou boas condições de depuração. A remoção da matéria carbonácea mostrou-se elevada, com eficiências médias de 92% de DBO5 e 80% de DQO. A remoção de nutrientes variou entre 59 e 71% para nitrogênio total e entre 45 e 67% para fósforo total. Tanto no lodo em suspensão, quanto no biofilme, foi observada a ocorrência de bactérias oxidadoras de amônio e micro-organismos responsáveis pela desnitrificação e remoção biológica de fósforo.This paper presents the results about the behavior of a sequencing batch hybrid reactor on combined removal of carbonaceous matter, nitrogen and phosphorus from sewage. Operated in 8-hour cycles, the reactor had a nylon net fixed inside. Loads between 0.39 and 1.35 kg COD.m-3.day-1, 42 and 60 gN-NH4-m-3.day-1 and 51 and 70 gP-PO4-m-3.day-1 were tested. The reactor operated as a stable system and showed good depuration conditions. The carbonaceous matter removal was high, with 92 and 80% efficiencies average to BOD5 and COD, respectively. The nutrients removal varied between 59 and 71% for total nitrogen and between 45 and 67% for total phosphorus. In both, sludge in suspension and the biofilm, occurrence of ammonium-oxidizing bacteria and microorganisms responsible for denitrification and biological phosphorus removal was observed.

  7. Influence of batch or fed-batch growth on Staphylococcus epidermidis biofilm formation

    OpenAIRE

    Cerca, Nuno; Pier, Gerald B.; Vilanova, Manuel; Oliveira, Rosário; Azeredo, Joana

    2004-01-01

    Aims: To make a quantitative evaluation of the differences in biofilm formation by Staphylococcus epidermidis using batch and fed-batch growth systems and to correlate this with production of the major biofilm polysaccharide, poly-N-acetyl glucosamine (PNAG). Methods and Results: Dry weight measurements of biofilms formed in batch and fed-batch conditions were compared with haemagglutination titres, which measure the amount of PNAG produced. Strains grown in batch systems devel...

  8. Transition to four batch loading scheme in Loviisa NPP

    International Nuclear Information System (INIS)

    The WWER-440 reactors of Loviisa NPP are operated with 1500 MWth power and reduced core. During recent years a 3-batch loading scheme has been used. Loviisa-1 is currently running with BNFL fuel equilibrium cycle and Loviisa-2 with TVEL fuel equilibrium cycle. Our goal is to move to a 4-batch scheme with TVEL fuel for both reactors. To achieve this goal the U-235 enrichment has to be increased from the current designs used. The fuel to be used in the near future is 4.37 % enriched fuel with six Gd2O3 doped rods. The characteristics and consequences of the core consisting of Gd-fuel are discussed based on our target equilibrium loading pattern. With the 4-batch loading scheme the discharge burnups exceed the current assembly burnup limit with a clear margin. Thus, we also have to prepare an application for the safety authority to increase the assembly average burnup limit from the current 45 MWd/kgU to about 56 MWd/kgU. First Gd-fuel assemblies are loaded into Loviisa-1 core in September 2009 and into Loviisa-2 core in October 2010. The reload batch of Loviisa-1 in 2009 consists of 60 Gd-assemblies and 24 non-Gd-assemblies plus 12 followers. In this paper some results are presented from Loviisa-1 zero power startup experiments and the first days of power operation. Among other aspects the six Gd2O3 doped pins used in the assembly have an effect on the pin power profile of the assembly during the first half of the cycle. The influence of the changing pin power profile on the outlet temperature measurements is briefly discussed based on expected effect and measurement (Authors)

  9. Quarterly report of the Swedish Nuclear Power Inspectorate

    International Nuclear Information System (INIS)

    The inspectorate is reporting on the departures of the nuclear power plants from normal operations. No safety incidents of importance occurred during the 4th quarter 1983. There have been 12 reactor trips for the 10 power units, 9 of those occurred on Dec. 27th, when the Southern Swedish power grid tripped.(P.Aa.)

  10. Combinatorial Batch Codes with Redundancy

    OpenAIRE

    Jung, Jiyoon; Mummert, Carl; Niese, Elizabeth; Schroeder, Michael w.

    2015-01-01

    A combinatorial batch code with redundancy $r$ and parameters $(n,k,m,t)$ can be represented as a system $C$ of $m$ (not necessarily distinct) subsets of an underlying $n$-element set $F$, so that each $k$-subset of $F$ can be covered by every $(m-r)$-subset $K$ of $C$ while taking no more than $t$ elements of $F$ with each set in $K$. The sum of the cardinalities of the sets in $C$ is the weight of the code. We focus on the case $t =1$, and determine the minimal weight for several ranges of ...

  11. EMSL Quarterly Highlights Report: 1st Quarter, Fiscal Year 2009

    Energy Technology Data Exchange (ETDEWEB)

    Showalter, Mary Ann; Kathmann, Loel E.; Manke, Kristin L.

    2009-02-02

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2008 - December 2008) of Fiscal Year 2009.

  12. EMSL Quarterly Highlights Report: FY 2008, 3rd Quarter

    Energy Technology Data Exchange (ETDEWEB)

    Showalter, Mary Ann

    2008-09-16

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2007 - December 2007) of Fiscal Year 2008.

  13. EMSL Quarterly Highlights Report: 1st Quarter, FY08

    Energy Technology Data Exchange (ETDEWEB)

    Showalter, Mary Ann

    2008-01-28

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2007 - December 2007) of Fiscal Year 2008.

  14. Optimal control of batch emulsion polymerization of vinyl chloride

    Energy Technology Data Exchange (ETDEWEB)

    Damslora, Andre Johan

    1998-12-31

    The highly exothermic polymerization of vinyl chloride (VC) is carried out in large vessels where the heat removal represents a major limitation of the production rate. Many emulsion polymerization reactors are operated in such a way that a substantial part of the heat transfer capacity is left unused for a significant part of the total batch time. To increase the reaction rate so that it matches the heat removal capacity during the course of the reaction, this thesis proposes the use of a sufficiently flexible initiator system to obtain a reaction rate which is high throughout the reaction and real-time optimization to compute the addition policy for the initiator. This optimization based approach provides a basis for an interplay between design and control and between production and research. A simple model is developed for predicting the polymerization rate. The model is highly nonlinear and open-loop unstable and may serve as an interesting case for comparison of nonlinear control strategies. The model is fitted to data obtained in a laboratory scale reactor. Finally, the thesis discusses optimal control of the emulsion polymerization reactor. Reduction of the batch cycle time is of major economic importance, as long as the quality parameters are within their specifications. The control parameterization had a major influence on the performance. A differentiable spline parameterization was applied and the optimization is illustrated in a number of cases. The best performance is obtained when the reactor temperature is obtained when the optimization is combined with some form of closed-loop control of the reactor temperature. 112 refs., 48 figs., 4 tabs.

  15. Rational design and optimization of fed-batch and continuous fermentations.

    Science.gov (United States)

    Zhang, Wenhui; Inan, Mehmet; Meagher, Michael M

    2007-01-01

    This chapter provides rational approaches to design and optimize fed-batch and continuous fermentations of both Mut+ and Muts (methanol utilization plus and slow) Pichia pastoris strains. The methods are described in detail for glycerol batch, glycerol fed-batch, transition, and methanol fed-batch/mixed feed/ continuous stirred tank reactor (CSTR) phases of the process based on glycerol and methanol consumption models. Cell density, broth volume, substrate feed rate, and the length of each phase are rationally designed to conduct runs with selected parameters for optimizing a process. The optimization is anchored by the impact of a specific growth rate/dilution time (for CSTRs) on productivity. Equations for simulation of a process with optimal parameters are derived for an optimal process design. This protocol can be used as a practical manual for process development of a P. pastoris recombinant fermentation, and also as a reference for fermentation of other microorganisms. PMID:17951634

  16. Remoção biológica de fósforo em reatores em bateladas sequenciais com diferentes tempos de retenção de sólidos Biological phosphorus removal in sequencing batch reactors with different solid retention times

    Directory of Open Access Journals (Sweden)

    Israel Nunes Henrique

    2010-06-01

    Full Text Available Nos últimos anos, tem surgido a necessidade de se projetarem sistemas de tratamento de águas residuárias que, além de remover carga orgânica, sejam capazes de remover nutrientes, particularmente nitrogênio e fósforo. Este trabalho avaliou a remoção biológica de fósforo em sistemas de lodo ativado, tratando esgoto doméstico por meio de reatores em bateladas sequenciais (RBS, monitorado com diferentes tempos de retenção celular (TRC: 20, 5 e 3 dias. Esses experimentos foram avaliados em escala de bancada com o uso da respirometria, utilizando-se acetato como fonte de carbono orgânico. Os resultados mostraram satisfatória remoção de fósforo total nos três experimentos, com valores médios entre 79 a 82%, sendo que o sistema RBS que operou com TRC de cinco dias obteve resultados melhores.In recent years, there has been an increasing need to design wastewater treatment systems that are capable of removing both organic material and nutrients, notably nitrogen and phosphorus. This study evaluated biological phosphorus removal by activated sludge systems fed with domestic sewage and operating as sequencing batch reactors (SBR with different solids retention times (SRT namely 20, 5 and 3 days. This was supported by respirometry experiments at bench scale using acetate as the source of organic carbon. The results showed satisfactory total phosphorus removal efficiencies mean values between 79-82% for the three regimes with the best removal efficiency occurring in the SBR operating with a five-day SRT.

  17. APPLICATION OF THE ANAEROBIC SEQUENCING BATCH REACTORS WITH FIXED FILM IN THE TREATMENT OF INDUSTRIAL WASTEWATER CONTAINING HIGH SULFATE CONCENTRATION = APLICAÇÃO DE REATORES ANAERÓBIOS OPERADOS EM BATELADAS SEQUENCIAIS COM FILME FIXO NO TRATAMENTO DE ÁGUA RESIDUARIA INDUSTRIAL RICA EM SULFATO

    Directory of Open Access Journals (Sweden)

    Eugenio Foresti

    2009-01-01

    Full Text Available This paper presents and discusses the potential for use of pilot-scale anaerobic sequencing batch biofilm reactors (ASBBR for the treatment of industrial wastewater containing high sulfate concentration. The pilot-scale ASBBR reactor (total volume=1.2 m3 containing biomass immobilized in inert support (mineral coal was operated at sulfate loading rates varying from 0.15 to 1.90 kgSO4-2/cycle (cycle of 48h corresponding to sulfate concentrations of 0.25 to 3.0 gSO4-2.L-1. Domestic sewage and ethanol were utilized as electron donors for sulfate reduction. The mean sulfate removal efficiencies remained in the range of 88 to 92% in the several sulfate concentrations obtained from 92 operational cycles. As post-treatment unit for the generated effluents by the sulfate reduction was used another reactor ASBBR in pilot-scale (total volume=385,0 L with same inert support for biomass immobilization and different granulometry. The mean COD removal (mean influent=1450 mg.L-1 achieved 88% and total sulfide concentrations (H2S, HS−, S2− remained in the range of 41 to 71 mg.L-1 during the 35 operational cycles of 48 h. The results demonstrated that the use of ASBBR reactors is an alternative potential for the sulfate removal and as post-treatment of generated effluent. = Este trabalho apresenta e discute o potencial de uso de reatores anaeróbios operados em bateladas seqüenciais com biomassa imobilizada (ASBBR, em escala piloto, no tratamento de água residuária industrial contendo elevadas concentrações de sulfato. No ASBBR, com volume total de 1,2 m3, preenchido com carvão mineral (meio suporte foram aplicadas cargas de sulfato de 0,15 a 1,90 kg/ciclo com duração de ciclo de 48 h, correspondendo, respectivamente, às concentrações de sulfato no afluente de 0,25 a 3,0 g.L-1. O esgoto sanitário e etanol foram usados como doadores de elétrons para a redução do sulfato. As eficiências médias na redução de sulfato ficaram entre 88 e 92% nos

  18. Remoção de fósforo de efluentes da parboilização de arroz por absorção biológica estimulada em reator em batelada sequencial (RBS Rice parboilization wastewater phosphorus removal by enhanced biological assimilation in sequencing batch reactor (SBR

    Directory of Open Access Journals (Sweden)

    Osvaldo Luís Vieira Faria

    2006-06-01

    Full Text Available O efluente do arroz parboilizado contém altas concentrações de fósforo. Um reator em batelada seqüencial (RBS alimentado com efluente de reator UASB, operou com três fases anaeróbias e aeróbias e tempo de detenção de sólidos (TDS de 25 d, 15 d, 10 d e 5d e tempo de reação (tR de 1 d, 2 d e 3 d com e sem a adição de ácido acético (HAc. O reator operou com o efluente do equalizador em duas fases tratando com TDS de cinco dias. A eficiência foi calculada pela relação entre a massa de fósforo suspenso descartada e a massa total alimentada. O maior potencial de remoção de 46,14 mg ocorreu operando-se com uma fase anaeróbia e uma aeróbia com adição de HAc. O tR de um dia tem a maior possibilidade de aumento da eficiência pelo incremento do descarte de biomassa. A operação com TDS menores obtém as maiores eficiências de remoção. A capacidade de remoção é melhor utilizada com TDS de cinco dias. A maior eficiência (E=17,82% foi obtida tratando o efluente do reator UASB com TDS de cinco dias, com duas fases, sem a adição HAc.The parboiled rice effluent has high phosphorus concentration. A sequential batch reactor (SBR was fed with a UASB reactor effluent and operated with three anaerobic and aerobic phases and solids retention time (SRT of 25 d, 15 d, 10 d and 5 d, and reaction time (tR of 1 d, 2 d and 3 d, with and without acetic acid (HOAc addition. The reactor operated with 5 d of SRT and two phases treating equalization tank effluent. The removal efficiency was calculated by the relation between phosphorus suspended wasted mass and feed mass. The biggest removal potential, 46.14 mg, was operated with HOAc addition and one anaerobic and aerobic phase. The biggest possibility of efficiency increase by biomass waste was obtained with tR=1 d. The system operating with smaller SRT achieves higher removal efficiencies. The removal capacity is better utilized with five days of SRT. The highest efficiency (E=17.82% was

  19. Batch processing: definition and event log identification

    OpenAIRE

    Martin, Niels,; SWENNEN, Marijke; Depaire, Benoit; Jans, Mieke; CARIS, An; Vanhoof, Koen

    2015-01-01

    A resource typically executes a particular activity on a series of cases. When a resource performs an activity on several cases simultaneously, (quasi-) sequentially or concurrently, this is referred to as batch processing. Given its influence on process performance, batch processing needs to be taken into account when modeling business processes for performance evaluation purposes. This paper suggests event logs as an information source to gain insight in batching behavior. It marks a first ...

  20. Batch process design: an overview from control

    OpenAIRE

    Zuluaga Bedoya, Christian Camilo

    2015-01-01

    Abstract: batch process design: an overview from control In this work, the topic of batch process design is addressed, through an analysis of the phenomenological-based model and using set-theoretic methods to deduce process constraints and parametric effects in state controllability. A review of literature is presented about characterization of batch process from point of view of design problem. Furthermore simultaneous process and control design is also reviewed, considering the main contri...