WorldWideScience

Sample records for landfill bioreactor design

  1. BIOREACTOR DESIGN - OUTER LOOP LANDFILL, LOUISVILLE, KY

    Science.gov (United States)

    Bioreactor field demonstration projects are underway at the Outer Loop Landfill in Louisville, KY, USA. The research effort is a cooperative research effort between US EPA and Waste Management Inc. Two primary kinds of municipal waste bioreactors are under study at this site. ...

  2. Bioreactor landfill

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; XING Kai; Anthony Adzomani

    2004-01-01

    Following the population expansion, there is a growing threat brought by municipal solid waste (MSW) against environment and human health. Sanitary landfill is the most important method of MSW disposal in China. In contrast to the conventional landfill, this paper introduces a new technique named bioreactor landfill (BL). Mechanisms, operation conditions as well as the advantages and disadvantages of BL are also discussed in this paper.

  3. STEADY-STATE DESIGN OF VERTICAL WELLS FOR LIQUIDS ADDITION AT BIOREACTOR LANDFILLS

    Science.gov (United States)

    This paper presents design charts that a landfill engineer can use for the design of a vertical well system for liquids addition at bioreactor landfills. The flow rate and lateral and vertical zones of impact of a vertical well were estimated as a function of input variables su...

  4. STEADY-STATE DESIGN OF VERTICAL WELLS FOR LIQUIDS ADDITION AT BIOREACTOR LANDFILLS

    Science.gov (United States)

    This paper presents design charts that a landfill engineer can use for the design of a vertical well system for liquids addition at bioreactor landfills. The flow rate and lateral and vertical zones of impact of a vertical well were estimated as a function of input variables su...

  5. Landfill leachate treatment in assisted landfill bioreactor

    Institute of Scientific and Technical Information of China (English)

    HE Pin-jing; QU Xian; SHAO Li-ming; LEE Duu-jong

    2006-01-01

    Landfill is the major disposal route of municipal solid waste(MSW) in most Asian countries. Leachate from landfill presents a strong wastewater that needs intensive treatment before discharge. Direct recycling was proposed as an effective alternative for leachate treatment by taking the landfill as a bioreactor. This process was proved not only considerably reducing the pollution potential of leachate, but also enhancing organic degradation in the landfill. However, as this paper shows, although direct leachate recycling was effective in landfilled MSW with low food waste fraction (3.5%, w/w), it failed in MSW containing 54% food waste, as normally noted in Asian countries. The initial acid stuck would inhibit methanogenesis to build up, hence strong leachate was yielded from landfill to threaten the quality of receiving water body. We demonstrated the feasibility to use an assisted bioreactor landfill, with a well-decomposed refuse layer as ex-situ anaerobic digester to reducing COD loading in leachate. By doing so, the refuse in simulated landfill column (2.3 m high) could be stabilized in 30 weeks while the COD in leachate reduced by 95%(61000 mg/L to 3000 mg/L). Meanwhile, the biogas production was considerably enhanced, signaling by the much greater amount and much higher methane content in the biogas.

  6. PRACTICE REVIEW OF FIVE BIOREACTOR/RECIRCULATION LANDFILLS

    Science.gov (United States)

    Six bioreactor landfills were analyzed to provide a perspective of current practice and technical issues that differentiate bioreactor landfills from conventional landfills. Five of the bioreactor landfills were anaerobic and one was aerated. In one case, nearly identical cells e...

  7. Aerobic landfill bioreactor

    Science.gov (United States)

    Hudgins, Mark P; Bessette, Bernard J; March, John; McComb, Scott T.

    2000-01-01

    The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  8. LANDFILL BIOREACTOR PERFORMANCE, SECOND INTERIM REPORT

    Science.gov (United States)

    A bioreactor landfill is a landfill that is operated in a manner that is expected to increase the rate and extent of waste decomposition, gas generation, and settlement compared to a traditional landfill. This Second Interim Report was prepared to provide an interpretation of fie...

  9. LANDFILL BIOREACTOR PERFORMANCE, SECOND INTERIM REPORT

    Science.gov (United States)

    A bioreactor landfill is a landfill that is operated in a manner that is expected to increase the rate and extent of waste decomposition, gas generation, and settlement compared to a traditional landfill. This Second Interim Report was prepared to provide an interpretation of fie...

  10. MONITORING APPROACHES FOR BIOREACTOR LANDFILLS - Report

    Science.gov (United States)

    Experimental bioreactor landfill operations at operating Municipal Solid Waste (MSW) landfills can be approved under the research development and demonstration (RD&D) provisions of 30CFR 258.4. To provide a basis for consistent data collection for future decision-making in suppor...

  11. MONITORING APPROACHES FOR BIOREACTOR LANDFILLS - Report

    Science.gov (United States)

    Experimental bioreactor landfill operations at operating Municipal Solid Waste (MSW) landfills can be approved under the research development and demonstration (RD&D) provisions of 30CFR 258.4. To provide a basis for consistent data collection for future decision-making in suppor...

  12. Methane production in simulated hybrid bioreactor landfill.

    Science.gov (United States)

    Xu, Qiyong; Jin, Xiao; Ma, Zeyu; Tao, Huchun; Ko, Jae Hac

    2014-09-01

    The aim of this work was to study a hybrid bioreactor landfill technology for landfill methane production from municipal solid waste. Two laboratory-scale columns were operated for about ten months to simulate an anaerobic and a hybrid landfill bioreactor, respectively. Leachate was recirculated into each column but aeration was conducted in the hybrid bioreactor during the first stage. Results showed that leachate pH in the anaerobic bioreactor maintained below 6.5, while in the hybrid bioreactor quickly increased from 5.6 to 7.0 due to the aeration. The temporary aeration resulted in lowering COD and BOD5 in the leachate. The volume of methane collected from the hybrid bioreactor was 400 times greater than that of the anaerobic bioreactor. Also, the methane production rate of the hybrid bioreactor was improved within a short period of time. After about 10 months' operation, the total methane production in the hybrid bioreactor was 212 L (16 L/kgwaste).

  13. Comparison between controlled landfill reactor and conditioned landfill bioreactor

    Institute of Scientific and Technical Information of China (English)

    LUO Feng; CHEN Wan-zhi; SONG Fu-zhong; LI Xiao-peng; ZHANG Guo-qing

    2004-01-01

    Bioreactor landfills allow a more active landfill management that recognizes the biological, chemical and physical processes involved in a landfill environment. The results of laboratory-scale simulators of landfill reactors treating municipal solid wastes were studied, the effect of solid waste size, leachate recirculation, nutrient balance, pH value, moisture content and temperature on the rate of municipal solid waste(MSW) biodegradation were determined, and it indicated the optimum pH value, moisture content and temperature can used to decompose MSW. The results of waste biodegradation were compared with that of the simulators of the leachate-recirculated landfill and conservative sanitary landfill. In the control experiment the antitheses of a decreasing trend of the organic load, measured as biological oxygen demand and chemical oxygen demand, was shown, and heavy metals concentration was observed. An obvious enhancement of effective disposal from simulator of conservative sanitary landfill(CSL), to that of leachate-recirculated landfill(LRL) and to that of conditioned bioreactor landfill(CBL) would be noted, through displaying the compared results of solid waste settlement, heavy metal concentration in leachate, methane production rate, biogas composition, BOD and COD as well as their ratio.

  14. Evaluation Of Landfill Gas Decay Constant For Municipal Solid Waste Landfills Operated As Bioreactors

    Science.gov (United States)

    Prediction of the rate of gas production from bioreactor landfills is important to optimize energy recovery and to estimate greenhouse gas emissions. Landfill gas (LFG) composition and flow rate were monitored for four years for a conventional and two bioreactor landfill landfil...

  15. Degradation of Refuse in Hybrid Bioreactor Landfill

    Institute of Scientific and Technical Information of China (English)

    YAN LONG; Yu-YANG LONG; HAI-CHUN LIU; DONG-SHENG SHEN

    2009-01-01

    Objectivess To explore the process of refuse decomposition in hybrid bioreactor landfill. Methods The bioreactor landfill was operated in sequencing of facultative-anaerobic and aerobic conditions with leachate recireulation, pH, COD, and ammonia in the leachate and pH, biodegradable organic matter (BDM), and cation exchange capacity (CEC) in refuse were detected. Results CEC increased gradually with the degradation of refuse, which was negatively correlad, With BDM. COD and ammonia in the leachate was declined to 399.2 mg L-1 and 20.6 mg N L-1, respectively, during the 357-day operation. The respective concentrations of ammonia and COD were below the second and the third levels of current discharge standards in China. Conclusion The refuse is relatively stable at the end of hybrid bioreactor landfill operation. Most of the readily biodegradable organic matter is mineralized in the initial phase of refuse degradation, whereas the hard-biodegradable organic matter is mainly humidified in the maturity phase of refuse degradation.

  16. STATE OF THE PRACTICE FOR BIOREACTOR LANDFILLS - SUMMARY OF USEPA WORKSHOP ON BIOREACTOR LANDFILLS: SUMMARY

    Science.gov (United States)

    This is a summary of the Workshop on Landfill Bioreactors, held 9/6-7/2000 in Arlington, VA. The purpose of the workshop was to provide a forum to EPA, state and local governments, solid waste industry, and academic research representatives to exchange information and ideas on b...

  17. STATE OF THE PRACTICE FOR BIOREACTOR LANDFILLS - SUMMARY OF USEPA WORKSHOP ON BIOREACTOR LANDFILLS: SUMMARY

    Science.gov (United States)

    This is a summary of the Workshop on Landfill Bioreactors, held 9/6-7/2000 in Arlington, VA. The purpose of the workshop was to provide a forum to EPA, state and local governments, solid waste industry, and academic research representatives to exchange information and ideas on b...

  18. Ammonia release and conversion in bioreactor landfill simulators

    Energy Technology Data Exchange (ETDEWEB)

    Lubberding, H.; Valencia, R.; Salazar, R.; Lens, P.

    2009-07-01

    Bioreactor landfills are considered to be an improvements to normal sanitary landfills, because the Municipal Solid Waste is stabilised faster and the biogas is produced in a shorter period of time (Valencia et al 2008a, b). In spite of these advantages, it is still difficult to reach within 30 years a safe status of the landfill due to the elevated NH{sub 4}{sup +} levels (up to 3 g/L) in the leachate. (Author)

  19. Releasing behavior of copper in recirculated bioreactor landfill.

    Science.gov (United States)

    Long, Yu-Yang; Hu, Li-Fang; Jiang, Chen-Jing; Fang, Cheng-Ran; Wang, Feng-Ping; Shen, Dong-Sheng

    2009-04-01

    The purpose of this study was to determine the releasing behavior of copper in municipal solid waste (MSW) in landfill with respect to refuse and leachate as an inseparable system. Two simulated bioreactor landfills, one with leachate recirculation and the other without, were operated in room temperature for 320 days. Copper in refuse showed behaviors of staggered migration and retention, which corresponded with the degradation process of landfill obviously. The significant different amounts of Cu2+ leached out from refuse into leachate of two landfills were 24.74 mg and 118.53 mg after 320 days' operation, respectively. It also reflected the releasing behavior of copper in landfill refuse at different stage accordingly. The results confirmed that the refuse in landfill had high potential of secondary pollution after closure.

  20. Permitting of Landfill Bioreactor Operations: Ten Years after ...

    Science.gov (United States)

    Prior to promulgation of the Rule, there were approximately 20 full-scale bioreactor projects in North America, including one in Canada. Of these, six were permitted by EPA (four Project XL sites and two projects listed separately under a cooperative research agreement at the Outer Loop Landfill in Kentucky). In March 2014, there were about 40 bioreactor projects reported, including 30 active RD&D projects in 11 approved states and one project on tribal lands. Wisconsin features the largest number of projects at 13, due primarily to the fact that landfill owners in the state must either eliminate landfill disposal of biodegradable materials or to achieve the complete stabilization of deposited organic waste at MSW landfills within 40 years after closure. Most landfill operators have selected a bioreactor approach to attempt to achieve the latter goal. In summary, only 16 of 50 (32%) states have currently adopted the Rule, meaning that development of RD&D permitting procedures that are consistent with EPA’s requirements has generally not occurred. The predominant single reason cited for not adopting the Rule was lack of interest amongst landfill facilities in the state. Subtitle D and its state derivatives already allow leachate recirculation over prescriptive (i.e., minimum technology) liner systems, which is often the primary goal of site operators seeking to control leachate treatment costs. Other reasons related to concerns over increased time, cost

  1. Performance of bioreactor landfill with waste mined from a dumpsite.

    Science.gov (United States)

    Karthikeyan, Obuli P; Swati, M; Nagendran, R; Joseph, Kurian

    2007-12-01

    Emissions from landfills via leachate and gas are influenced by state and stability of the organic matter in the solid waste and the environmental conditions within the landfill. This paper describes a modified, ecologically sound waste treatment technique, where municipal solid waste is anaerobically treated in a lysimeter-scale landfill bioreactor with leachate recirculation to enhance organic degradation. The results demonstrate a substantial decrease in organic matter (BOD 99%, COD 88% and TOC 81%) and a clear decrease in nutrient concentrations especially ammonia (85%) over a period of 1 year with leachate recirculation.

  2. MEASUREMENT OF FUGITIVE EMISSIONS AT A BIOREACTOR LANDFILL

    Science.gov (United States)

    This report focuses on three field campaigns performed in 2002 and 2003 to measure fugitive emissions at a bioreactor landfill in Louisville, KY, using an open-path Fourier transform infrared spectrometer. The study uses optical remote sensing-radial plume mapping. The horizontal...

  3. MEASUREMENT OF FUGITIVE EMISSIONS AT A BIOREACTOR LANDFILL

    Science.gov (United States)

    This report focuses on three field campaigns performed in 2002 and 2003 to measure fugitive emissions at a bioreactor landfill in Louisville, KY, using an open-path Fourier transform infrared spectrometer. The study uses optical remote sensing-radial plume mapping. The horizontal...

  4. Basic bioreactor design.

    NARCIS (Netherlands)

    Riet, van 't K.; Tramper, J.

    1991-01-01

    Based on a graduate course in biochemical engineering, provides the basic knowledge needed for the efficient design of bioreactors and the relevant principles and data for practical process engineering, with an emphasis on enzyme reactors and aerated reactors for microorganisms. Includes exercises.

  5. Basic bioreactor design.

    NARCIS (Netherlands)

    Riet, van 't K.; Tramper, J.

    1991-01-01

    Based on a graduate course in biochemical engineering, provides the basic knowledge needed for the efficient design of bioreactors and the relevant principles and data for practical process engineering, with an emphasis on enzyme reactors and aerated reactors for microorganisms. Includes exercises.

  6. Pilot-scale nitrogen removal from leachate by ex situ nitrification and in situ denitrification in a landfill bioreactor.

    Science.gov (United States)

    Sun, Faqian; Sun, Bin; Li, Qian; Deng, Xiaoya; Hu, Jian; Wu, Weixiang

    2014-04-01

    A combined process consisting of ex situ nitrification and in situ denitrification in landfill refuse was studied in pilot scale for nitrogen removal from municipal landfill leachate. The results showed that above 80% of partial nitrification ratio and an average COD loading rate of 1.50 kg m(-3) d(-1) were steadily maintained under DO concentrations of 1.0-1.7 mg L(-1) in the aerobic reactor. Quantitative PCR results indicated that nitrite-oxidizing bacteria being sensitive to DO fluctuations lead to partial nitrification when free ammonia inhibition was weak. Nitrified landfill leachate could be denitrified in the landfill bioreactor with maximum total oxidizing nitrogen removal rate of 67.2 g N t(-1) TSwaste d(-1). Clone and sequencing analysis of denitrifying bacterial nirS gene inferred that heterotrophic denitrifier Azoarcus tolulyticu was the primary nitrogen converter in the landfill bioreactor. The obtained results will provide valuable information for optimizing the design and operation of a landfill bioreactor.

  7. T2LBM Version 1.0: Landfill bioreactor model for TOUGH2

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, Curtis M.

    2001-05-22

    The need to control gas and leachate production and minimize refuse volume in landfills has motivated the development of landfill simulation models that can be used by operators to predict and design optimal treatment processes. T2LBM is a module for the TOUGH2 simulator that implements a Landfill Bioreactor Model to provide simulation capability for the processes of aerobic or anaerobic biodegradation of municipal solid waste and the associated flow and transport of gas and liquid through the refuse mass. T2LBM incorporates a Monod kinetic rate law for the biodegradation of acetic acid in the aqueous phase by either aerobic or anaerobic microbes as controlled by the local oxygen concentration. Acetic acid is considered a proxy for all biodegradable substrates in the refuse. Aerobic and anaerobic microbes are assumed to be immobile and not limited by nutrients in their growth. Methane and carbon dioxide generation due to biodegradation with corresponding thermal effects are modeled. The numerous parameters needed to specify biodegradation are input by the user in the SELEC block of the TOUGH2 input file. Test problems show that good matches to laboratory experiments of biodegradation can be obtained. A landfill test problem demonstrates the capabilities of T2LBM for a hypothetical two-dimensional landfill scenario with permeability heterogeneity and compaction.

  8. Design challenges for space bioreactors

    Science.gov (United States)

    Seshan, P. K.; Petersen, G. R.

    1989-01-01

    The design of bioreactors for operation under conditions of microgravity presents problems and challenges. Absence of a significant body force such as gravity can have profound consequences for interfacial phenomena. Marangoni convection can no longer be overlooked. Many speculations on the advantages and benefits of microgravity can be found in the literature. Initial bioreactor research considerations for space applications had little regard for the suitability of the designs for conditions of microgravity. Bioreactors can be classified in terms of their function and type of operation. The complex interaction of parameters leading to optimal design and operation of a bioreactor is illustrated by the JSC mammalian cell culture system. The design of a bioreactor is strongly dependent upon its intended use as a production unit for cell mass and/or biologicals or as a research reactor for the study of cell growth and function. Therefore a variety of bioreactor configurations are presented in rapid summary. Following this, a rationale is presented for not attempting to derive key design parameters such as the oxygen transfer coefficient from ground-based data. A set of themes/objectives for flight experiments to develop the expertise for design of space bioreactors is then proposed for discussion. These experiments, carried out systematically, will provide a database from which engineering tools for space bioreactor design will be derived.

  9. PERFORMANCE OF NORTH AMERICAN BIOREACTOR LANDFILLS: II. CHEMICAL AND BIOLOGICAL CHARACTERISTICS

    Science.gov (United States)

    The objective of this research was to examine the performance of five North American bioreactor landfills. This paper represents the second of a two part series and addresses biological and chemical aspects of bioreactor performance including gas production and management, and l...

  10. PERFORMANCE OF NORTH AMERICAN BIOREACTOR LANDFILLS: II. CHEMICAL AND BIOLOGICAL CHARACTERISTICS

    Science.gov (United States)

    The objective of this research was to examine the performance of five North American bioreactor landfills. This paper represents the second of a two part series and addresses biological and chemical aspects of bioreactor performance including gas production and management, and l...

  11. Treatment of mechanically sorted organic waste by bioreactor landfill: Experimental results and preliminary comparative impact assessment with biostabilization and conventional landfill.

    Science.gov (United States)

    Di Maria, Francesco; Micale, Caterina; Sisani, Luciano; Rotondi, Luca

    2016-09-01

    Treatment and disposal of the mechanically sorted organic fraction (MSOF) of municipal solid waste using a full-scale hybrid bioreactor landfill was experimentally analyzed. A preliminary life cycle assessment was used to compare the hybrid bioreactor landfill with the conventional scheme based on aerobic biostabilization plus landfill. The main findings showed that hybrid bioreactor landfill was able to achieve a dynamic respiration index (DRI)55% v/v started within 140days from MSOF disposal, allowing prompt energy recovery and higher collection efficiency. With the exception of fresh water eutrophication with the bioreactor scenario there was a reduction of the impact categories by about 30% compared to the conventional scheme. Such environmental improvement was mainly a consequence of the reduction of direct and indirect emissions from conventional aerobic biostabilization and of the lower amount of gaseous loses from the bioreactor landfill. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Heavy metals mobility in full-scale bioreactor landfill: initial stage.

    Science.gov (United States)

    Qu, Xian; He, Pin-Jing; Shao, Li-Ming; Lee, Duu-Jong

    2008-01-01

    Selected heavy metals (HMs) including Cd, Cr, Cu, Ni, Pb and Zn initially released from a full-scale bioreactor landfill were monitored over the first 20 months of operation. At the initial landfill stage, the leachate exhibited high HMs release, high organic matter content (27000-43000gl(-1) of TOC) and low pH (5-6). By the fifth month of landfilling, the methanogenic stage had been established, and HMs release was reduced below the Chinese National Standards. Total released HMs accounted for less than 1% of landfill deposited during the investigated period. Most landfill HMs were inorganic. Fourier-transform infrared (FT-IR) spectra data and model calculations using Visual MINTEQ indicated that humic substances strongly affected the mobility of organic fractions of HMs in the methanogenic landfill. The initial rates of HMs release could be enhanced by recycling the leachate back to bioreactor landfill, but the total quantity released may be reduced by early establishment of methanogenic stage in bioreactor landfill.

  13. Effects of aeration frequency on leachate quality and waste in simulated hybrid bioreactor landfills.

    Science.gov (United States)

    Ko, Jae Hac; Ma, Zeyu; Jin, Xiao; Xu, Qiyong

    2016-12-01

    Research has been conducted to investigate the effects of daily aeration frequency on leachate quality and waste settlement in simulated hybrid landfill bioreactors. Four laboratory-scale reactors were constructed and operated for about 10 months to simulate different bioreactor operations, including one anaerobic bioreactor and three hybrid bioreactors with different aeration frequencies (one, two, and four times per day). Chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) reduced more than 96% of the initial concentrations in all aerated bioreactors. The differences of COD and BOD5 reductions among tested aeration frequencies were relatively small. For ammonia nitrogen, the higher aeration frequency (two or four times per day) resulted in the quicker reduction. Overall, the concentrations of heavy metals (Cr, Co, Cu, Mn, Ni, and Zn) decreased over time except Cd and Pb. The reduction of redox-sensitive metal concentrations (Mn, Co, Ni, and Cu) was greater in aerated bioreactors than in anaerobic bioreactor. Settlement of municipal solid waste (MSW) was enhanced with higher frequency of aeration events (four times per day). In recent years, hybird bioreactor landfill technology has gained a lot of attention. Appropriate aeration rate is crucial for hybrid bioreactor operation, but few studies have been done and different results were obtained. Research was conducted to investigate the effects of daily aeration frequency on leachate quality and waste settlement. Results indicated that aeration can effectively accelerate waste stabilization and remove organic carbon concentration and total nitrogen in the leachate.

  14. Landfill gas management facilities design guidelines

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-03-15

    In British Columbia, municipal solid waste landfills generate over 1000 tonnes of methane per year; landfill gas management facilities are required to improve the environmental performance of solid waste landfills. The aim of this document, developed by the British Columbia Ministry of the Environment, is to provide guidance for the design, installation, and operation of landfill gas management facilities to address odor and pollutant emissions issues and also address health and safety issues. A review of technical experience and best practices in landfill gas management facilities was carried out, as was as a review of existing regulations related to landfill gas management all over the world. This paper provides useful information to landfill owners, operators, and other professionals for the design of landfill gas management facilities which meet the requirements of landfill gas management regulations.

  15. PERFORMANCE OF NORTH AMERICAN BIOREACTOR LANDFILLS: I. LEACHATE HYDROLOGY AND WASTE SETTLEMENT

    Science.gov (United States)

    An assessment of state-of-the-practice at five full-scale North American landfills operating as bioreactors is presented in this two-paper set. This paper focuses on effectiveness of liners and leachate collection systems, leachate generation rates, leachate recirculation practi...

  16. PERFORMANCE OF NORTH AMERICAN BIOREACTOR LANDFILLS: I. LEACHATE HYDROLOGY AND WASTE SETTLEMENT

    Science.gov (United States)

    An assessment of state-of-the-practice at five full-scale North American landfills operating as bioreactors is presented in this two-paper set. This paper focuses on effectiveness of liners and leachate collection systems, leachate generation rates, leachate recirculation practi...

  17. Biogas production enhancement using semi-aerobic pre-aeration in a hybrid bioreactor landfill.

    Science.gov (United States)

    Cossu, Raffaello; Morello, Luca; Raga, Roberto; Cerminara, Giulia

    2016-09-01

    Landfilling continues to be one of the main methods used in managing Municipal Solid Waste (MSW) worldwide, particularly in developing countries. Although in many countries national legislation aims to reduce this practice as much as possible, landfill is a necessary and unavoidable step in closing the material cycle. The need for innovative waste management techniques to improve landfill management and minimize the adverse environmental impact produced has resulted in an increasing interest in innovative systems capable of accelerating waste stabilization. Landfill bioreactors allow decomposition kinetics to be increased and post-operational phase to be shortened; in particular, hybrid bioreactors combine the benefits afforded by both aerobic and anaerobic processes. Six bioreactor simulators were used in the present study: four managed as hybrid, with an initial semi-aerobic phase and a second anaerobic phase, and two as anaerobic control bioreactors. The main goal of the first aerated phase is to reduce Volatile Fatty Acids (VFA) in order to increase pH and enhance methane production during the anaerobic phase; for this reason, air injection was stopped only when these parameters reached the optimum range for methanogenic bacteria. Biogas and leachate were constantly monitored throughout the entire methanogenic phase with the aim of calibrating a Gompertz Model and evaluating the effects of pre-aeration on subsequent methane production. The results showed that moderate and intermittent pre-aeration produces a positive effect both on methane potential and in the kinetics of reaction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Achieving "Final Storage Quality" of municipal solid waste in pilot scale bioreactor landfills.

    Science.gov (United States)

    Valencia, R; van der Zon, W; Woelders, H; Lubberding, H J; Gijzen, H J

    2009-01-01

    Entombed waste in current sanitary landfills will generate biogas and leachate when physical barriers fail in the future, allowing the intrusion of moisture into the waste mass contradicting the precepts of the sustainability concept. Bioreactor landfills are suggested as a sustainable option to achieve Final Storage Quality (FSQ) status of waste residues; however, it is not clear what characteristics the residues should have in order to stop operation and after-care monitoring schemes. An experiment was conducted to determine the feasibility to achieve FSQ status (Waste Acceptance Criteria of the European Landfill Directive) of residues in a pilot scale bioreactor landfill. The results of the leaching test were very encouraging due to their proximity to achieve the proposed stringent FSQ criterion after 2 years of operation. Furthermore, residues have the same characteristics of alternative waste stabilisation parameters (low BMP, BOD/COD ratio, VS content, SO4(2-)/Cl- ratio) established by other researchers. Mass balances showed that the bioreactor landfill simulator was capable of practically achieving biological stabilisation after 2 years of operation, while releasing approximately 45% of the total available (organic and inorganic) carbon and nitrogen into the liquid and gas phases.

  19. COMMERCIAL-SCALE AEROBIC-ANAEROBIC BIOREACTOR LANDFILL OPERATIONS

    Science.gov (United States)

    A sequential aerobic-anaerobic treatment system has been applied at a commercial scale (3,000 ton per day) municipal solid waste landfill in Kentucky, USA since 2001. In this system, the uppermost layer of landfilled waste is aerated and liquid waste including leachate, surface w...

  20. COMMERCIAL-SCALE AEROBIC-ANAEROBIC BIOREACTOR LANDFILL OPERATIONS

    Science.gov (United States)

    A sequential aerobic-anaerobic treatment system has been applied at a commercial scale (3,000 ton per day) municipal solid waste landfill in Kentucky, USA since 2001. In this system, the uppermost layer of landfilled waste is aerated and liquid waste including leachate, surface w...

  1. Integrating landfill bioreactors, partial nitritation and anammox process for methane recovery and nitrogen removal from leachate

    Science.gov (United States)

    Sun, Faqian; Su, Xiaomei; Kang, Tingting; Wu, Songwei; Yuan, Mengdong; Zhu, Jing; Zhang, Xiayun; Xu, Fang; Wu, Weixiang

    2016-06-01

    A new process consisting of a landfill bioreactor, partial-nitritation (PN) and the anammox process has been developed for landfill leachate treatment. In this study, the landfill bioreactor exhibited excellent performance in methane-rich biogas recovery, with a specific biogas yield of 0.47 L gas g-1 COD and methane percentages of 53-76%. PN was achieved in the aerobic reactor by high free ammonia (101 ± 83 mg NH3 L-1) inhibition for nitrite-oxidizing bacteria, and the desired PN effluent composition (effluent nitrite: ammonium ratio of 1.1 ± 0.3) was controlled by adjusting the alkalinity concentration per unit of ammonium oxidized to approximately 14.3 mg CaCO3 mg-1 N in the influent. The startup of anammox process was successfully achieved with a membrane bioreactor in 160 d, and a maximum nitrogen removal rate of 216 mg N L-1 d-1 was attained for real landfill leachate treatment. The quantitative polymerase chain reaction results confirmed that the cell-specific anammox activity was approximately 68-95 fmol N cell-1 d-1, which finally led to the stable operation of the system.

  2. Yolo County's Accelerated Anaerobic and Aerobic Composting (Full-Scale Controlled Landfill Bioreactor) Project

    Science.gov (United States)

    Yazdani, R.; Kieffer, J.; Akau, H.; Augenstein, D.

    2002-12-01

    Sanitary landfilling is the dominant method of solid waste disposal in the United States, accounting for about 217 million tons of waste annually (U.S. EPA, 1997) and has more than doubled since 1960. In spite of increasing rates of reuse and recycling, population and economic growth will continue to render landfilling as an important and necessary component of solid waste management. Yolo County Department of Planning and Public Works, Division of Integrated Waste Management is demonstrating a new landfill technology called Bioreactor Landfill to better manage solid waste. In a Bioreactor Landfill, controlled quantities of liquid (leachate, groundwater, gray-water, etc.) are added and recirculated to increase the moisture content of the waste and improve waste decomposition. As demonstrated in a small-scale demonstration project at the Yolo County Central Landfill in 1995, this process significantly increases the biodegradation rate of waste and thus decreases the waste stabilization and composting time (5 to 10 years) relative to what would occur within a conventional landfill (30 to 50 years or more). When waste decomposes anaerobically (in absence of oxygen), it produces landfill gas (biogas). Biogas is primarily a mixture of methane, a potent greenhouse gas, carbon dioxide, and small amounts of Volatile Organic Compounds (VOC's) which can be recovered for electricity or other uses. Other benefits of a bioreactor landfill composting operation include increased landfill waste settlement which increases in landfill capacity and life, improved leachate chemistry, possible reduction of landfill post-closure management time, opportunity to explore decomposed waste for landfill mining, and abatement of greenhouse gases through highly efficient methane capture over a much shorter period of time than is typical of waste management through conventional landfilling. This project also investigates the aerobic decomposition of waste of 13,000 tons of waste (2.5 acre) for

  3. Impact of vent pipe diameter on characteristics of waste degradation in semi-aerobic bioreactor landfill.

    Science.gov (United States)

    Jiang, Guobin; Liu, Dan; Chen, Weiming; Ye, Zhicheng; Liu, Hong; Li, Qibin

    2017-08-01

    The evolution mechanism of a vent pipe diameter on a waste-stabilization process in semi-aerobic bioreactor landfills was analyzed from the organic-matter concentration, biodegradability, spectral characteristics of dissolved organic matter, correlations and principal-component analysis. Waste samples were collected at different distances from the vent pipe and from different landfill layers in semi-aerobic bioreactor landfills with different vent pipe diameters. An increase in vent pipe diameter favored waste degradation. Waste degradation in landfills can be promoted slightly when the vent pipe diameter increases from 25 to 50 mm. It could be promoted significantly when the vent pipe diameter was increased to 75 mm. The vent pipe diameter is important in waste degradation in the middle layer of landfills. The dissolved organic matter in the waste is composed mainly of long-wave humus (humin), short-wave humus (fulvic acid) and tryptophan. The humification levels of the waste that was located at the center of vent pipes with 25-, 50- and 75-mm diameters were 2.2682, 4.0520 and 7.6419 Raman units, respectively. The appropriate vent pipe diameter for semi-aerobic bioreactor landfills with an 800-mm diameter was 75 mm. The effect of different vent pipe diameters on the degree of waste stabilization is reflected by two main components. Component 1 is related mainly to the content of fulvic acid, biologically degradable material and organic matter. Component 2 is related mainly to the content of tryptophan and humin from the higher vascular plants.

  4. 40 CFR 258.41 - Project XL Bioreactor Landfill Projects.

    Science.gov (United States)

    2010-07-01

    ... geosynthetic clay liner (GCL) overlaying and in direct contact with the 18 inches of compacted soil in... direct and uniform contact with an overlaying soil cushioning component. (v) Underlying the above liner... recirculation is allowed only to the extent that the integrity of the landfill including its liner system...

  5. Nitrogen removal through different pathways in an aged refuse bioreactor treating mature landfill leachate.

    Science.gov (United States)

    Xie, Bing; Lv, Zhuo; Hu, Chong; Yang, Xuezhi; Li, Xiangzhen

    2013-10-01

    In this study, an aged refuse bioreactor was constructed to remove nitrogen in a mature landfill leachate. The nitrogen removal efficiency and the microbial community composition in the bioreactor were investigated. The results showed that the aged refuse bioreactor removed more than 90 % of total nitrogen in the leachate under the nitrogen loading rate (NLR) of 0.74 g/kg (vs) day, and the total nitrogen removal rate decreased to 62.2 % when NLR increased up to 2.03 g/kg (vs) day. Quantitative polymerase chain reaction results showed that the average cell number of ammonia-oxidizing bacteria in the bioreactor was 1.58 × 10(8) cells/g, which accounted for 0.41 % of total bacteria. The number of anammox bacteria in the reactor was 1.09 × 10(8) cells/g, which accounted for 0.27 % of total bacteria. Isotopic (15)N tracing experiments showed that nearly 10 % of nitrogen was removed by anammox. High-throughout 454 pyrosequencing revealed that the predominant bacteria in the bioreactor were Proteobacteria, Chloroflexi, Actinobacteria, Bacteroidetes, and Gemmatimonadetes, including various nitrifiers and denitrifiers with diverse heterotrophic and autotrophic metabolic pathways, supporting that nitrogen was removed through different pathways in this aged refuse bioreactor.

  6. Full Scale Bioreactor Landfill for Carbon Sequestration and Greenhouse Emission Control

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Kathy Sananikone; Don Augenstein

    2005-03-30

    The Yolo County Department of Planning and Public Works constructed a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective was to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entailed the construction of a 12-acre module that contained a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells were highly instrumented to monitor bioreactor performance. Liquid addition commenced in the 3.5-acre anaerobic cell and the 6-acre anaerobic cell. Construction of the 2.5-acre aerobic cell and biofilter has been completed. The current project status and preliminary monitoring results are summarized in this report.

  7. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2002-01-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches while providing superior environmental protection. The overall objective is to manage landfill solid waste for rapid waste decomposition, maximum landfill gas generation and capture, and minimum long-term environmental consequences. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. The current project status and preliminary monitoring results are summarized in this report.

  8. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2003-12-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Liquid addition has commenced in the 3.5-acre anaerobic cell and the 6-acre anaerobic cell. Construction of the 2.5-acre aerobic cell and biofilter has been completed. The remaining task to be completed is to test the biofilter prior to operation, which is currently anticipated to begin in January 2004. The current project status and preliminary monitoring results are summarized in this report.

  9. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2002-02-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches while providing superior environmental protection. The overall objective is to manage landfill solid waste for rapid waste decomposition, maximum landfill gas generation and capture, and minimum long-term environmental consequences. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. The current project status and preliminary monitoring results are summarized in this report.

  10. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2003-05-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Construction is complete on the 3.5-acre anaerobic cell and liquid addition has commenced. Construction of the 2.5-acre aerobic cell is nearly complete with only the biofilter remaining and construction of the west-side 6-acre anaerobic cell is nearly complete with only the liquid addition system remaining. The current project status and preliminary monitoring results are summarized in this report.

  11. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2002-04-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches while providing superior environmental protection. The overall objective is to manage landfill solid waste for rapid waste decomposition, maximum landfill gas generation and capture, and minimum long-term environmental consequences. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Construction is complete on the 3.5 acre anaerobic cell and liquid addition has commenced. Construction of the 2.5 acre aerobic cell is nearly complete with only the blower station and biofilter remaining. Waste placement and instrumentation installation is ongoing in the west-side 6-acre anaerobic cell. The current project status and preliminary monitoring results are summarized in this report.

  12. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2003-08-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Liquid addition has commenced in the 3.5-acre anaerobic cell and the 6-acre anaerobic cell. Construction of the 2.5-acre aerobic cell is nearly complete with only the biofilter remaining and is scheduled to be complete by the end of August 2003. The current project status and preliminary monitoring results are summarized in this report.

  13. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2002-08-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Construction is complete on the 3.5-acre anaerobic cell and liquid addition has commenced. Construction of the 2.5 acre aerobic cell is nearly complete with only the blower station and biofilter remaining. Waste placement and instrumentation installation is ongoing in the west-side 6-acre anaerobic cell. The current project status and preliminary monitoring results are summarized in this report.

  14. FULL SCALE BIOREACTOR LANDFILL FOR CARBON SEQUESTRATION AND GREENHOUSE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Ramin Yazdani; Jeff Kieffer; Heather Akau

    2003-12-01

    The Yolo County Department of Planning and Public Works is constructing a full-scale bioreactor landfill as a part of the Environmental Protection Agency's (EPA) Project XL program to develop innovative approaches for carbon sequestration and greenhouse emission control. The overall objective is to manage landfill solid waste for rapid waste decomposition and maximum landfill gas generation and capture for carbon sequestration and greenhouse emission control. Waste decomposition is accelerated by improving conditions for either the aerobic or anaerobic biological processes and involves circulating controlled quantities of liquid (leachate, groundwater, gray water, etc.), and, in the aerobic process, large volumes of air. The first phase of the project entails the construction of a 12-acre module that contains a 6-acre anaerobic cell, a 3.5-acre anaerobic cell, and a 2.5-acre aerobic cell at the Yolo County Central Landfill near Davis, California. The cells are highly instrumented to monitor bioreactor performance. Liquid addition has commenced in the 3.5-acre anaerobic cell and the 6-acre anaerobic cell. Construction of the 2.5-acre aerobic cell and biofilter has been completed. The remaining task to be completed is to test the biofilter prior to operation, which is currently anticipated to begin in January 2004. The current project status and preliminary monitoring results are summarized in this report.

  15. Performance evaluation of the bioreactor landfill in treatment and stabilisation of mechanically biologically treated municipal solid waste.

    Science.gov (United States)

    Lakshmikanthan, P; Sivakumar Babu, G L

    2017-03-01

    The potential of bioreactor landfills to treat mechanically biologically treated municipal solid waste is analysed in this study. Developing countries like India and China have begun to investigate bioreactor landfills for municipal solid waste management. This article describes the impacts of leachate recirculation on waste stabilisation, landfill gas generation, leachate characteristics and long-term waste settlement. A small-scale and large-scale anaerobic cell were filled with mechanically biologically treated municipal solid waste collected from a landfill site at the outskirts of Bangalore, India. Leachate collected from the same landfill site was recirculated at the rate of 2-5 times a month on a regular basis for 370 days. The total quantity of gas generated was around 416 L in the large-scale reactor and 21 L in the small-scale reactor, respectively. Differential settlements ranging from 20%-26% were observed at two different locations in the large reactor, whereas 30% of settlement was observed in the small reactor. The biological oxygen demand/chemical oxygen demand (COD) ratio indicated that the waste in the large reactor was stabilised at the end of 1 year. The performance of the bioreactor with respect to the reactor size, temperature, landfill gas and leachate quality was analysed and it was found that the bioreactor landfill is efficient in the treatment and stabilising of mechanically biologically treated municipal solid waste.

  16. Bioreactor design and optimization – a future perspective

    DEFF Research Database (Denmark)

    Gernaey, Krist

    2011-01-01

    Bioreactor design and optimisation are essential in translating the experience gained from lab or pilot scale experiments to efficient production processes in industrial scale bioreactors. This article gives a future perspective on bioreactor design and optimisation, where it is foreseen...

  17. LANDFILLS AS BIOREACTORS: RESEARH AT THE OUTER LOOP LANDFILL, LOUISVILLE, KENTUCKY; FIRST INTERIM REPORT

    Science.gov (United States)

    Interim report resulting from a cooperative research and development agreement (CRADA) between US EP A's Officeof Research and Development - National Risk Management Research Laboratory and a n ongoing field demonstrationof municipal waste landfills being operated as bioreact...

  18. Co-disposal of electronic waste with municipal solid waste in bioreactor landfills.

    Science.gov (United States)

    Visvanathan, C; Visvanthan, C; Yin, Nang Htay; Karthikeyan, Obuli P

    2010-12-01

    Three pilot scale lysimeters were adopted to evaluate the stability pattern and leaching potential of heavy metals from MSW landfills under the E-waste co-disposed condition. One lysimeter served as control and solely filled with MSW, whereas the other two lysimeters were provided with 10% and 25% of E-waste scraps (% by weight), respectively. The reactors were monitored over a period of 280 days at ambient settings with continuous leachate recirculation. Stabilization pattern of carbon appears to be more than 50% in all the three lysimeters with irrespective of their operating conditions. Iron and zinc concentrations were high in leachate during bioreactor landfill operation and correlating with the TCLP leachability test results. In contrast, Pb concentration was around waste was found to be amplified with the long term disposal or stabilization within landfills. The results showed that the TCLP test cannot be completely reliable tool for measuring long-term leachability of toxic substances under landfill condition; rather landfill lysimeter studies are necessary to get the real scenario.

  19. GEOTECHNICAL DESIGN OF SOLID WASTE LANDFILL SITES

    Directory of Open Access Journals (Sweden)

    Suat AKBULUT

    2003-02-01

    Full Text Available Solid waste landfills are important engineering structures for protection of wastes, decrease of environmental pollution, and especially prevention of soil and water pollution. Solid wastes should conveniently be maintained in landfill areas to control environmental pollution caused by waste disposals. Until the middle of this century clay liners were used for maintenance of waste disposal, but it was observed that these liner systems were insufficient. Today thinner and less permeable liner systems are constructed by using synthetic materials. In this study, by evaluating the waste landfills, site assessment of landfills and construction of natural and synthetic liner systems were summarized respectively, and especially the design properties of these systems were examined intensively. Also, leachate collection and removal facilities, landfill gas collection unites, and final cover unites were evaluated in a detailed way.

  20. Neural Network Modeling and Prediction of Methane Fraction in Biogas from Landfill Bioreactors

    Directory of Open Access Journals (Sweden)

    A Ghavidel

    2009-09-01

    Full Text Available "n "nBackgrounds and Objectives:A number of different technologies have recently been studied todetermine the best use of biogas, however, to choose optimize technologies of using biogas for energy recovery it is necessary to monitor and predict the methane percentage of biogas. In this study, a method is proposed for predicting the methane fraction in landfill gas originating from Labscalelandfill bioreactors, based on neural network."nMaterials and Methods: In this study, two different systems were applied, to predict the methane fraction in landfill gas as a final product of anaerobic digestion, we used the leachate specifications as input parameters. In system I (C1, the leachate generated from a fresh-waste reactor was drained to recirculation tank, and recycled. In System II (C2, the leachate generated from a fresh waste landfill reactor was fed through a well-decomposed refuse landfill reactor, and at the same time, the leachate generated from a well-decomposed refuse landfill reactor recycled to a fresh waste landfill reactor."nResults: There is very good agreement in the trends between forecasted and measured data. R valuesare 0.999 and 0.997, and the obtained Root mean square error values are 1.098 and 2.387 for training and test data, respectively"nConclusion: The proposed method can significantly predict the methane fraction in landfill gasoriginating and, consequently, neural network can be use to optimize the dimensions of a plant using biogas for energy (i.e. heat and/or electricity recovery and monitoring system.

  1. Bioreactor

    Science.gov (United States)

    1996-01-01

    The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues currently being cultured in rotating bioreactors by investigators

  2. Bioreactor Design for Tendon/Ligament Engineering

    Science.gov (United States)

    Wang, Tao; Gardiner, Bruce S.; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B.; Wang, Allan; Xu, Jiake

    2013-01-01

    Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a suitable culture environment, which mimics the dynamics of the in vivo environment for tendon/ligament maturation. For clinical settings, bioreactors also have the advantages of less-contamination risk, high reproducibility of cell propagation by minimizing manual operation, and a consistent end product. In this review, we identify the key components, design preferences, and criteria that are required for the development of an ideal bioreactor for engineering tendons and ligaments. PMID:23072472

  3. Hollow-fiber membrane bioreactor for the treatment of high-strength landfill leachate

    KAUST Repository

    Rizkallah, Marwan

    2013-07-15

    Performance assessment of membrane bioreactor (MBR) technology for the treatability of high-strength landfill leachate is relatively limited or lacking. This study examines the feasibility of treating high-strength landfill leachate using a hollow-fiber MBR. For this purpose, a laboratory-scale MBR was constructed and operated to treat leachate with a chemical oxygen demand (COD) of 9000-11,000 mg/l, a 5-day biochemical oxygen demand (BOD5) of 4000-6,000 mg/l, volatile suspended solids (VSS) of 300-500 mg/l, total nitrogen (TN) of 2000-6000 mg/l, and an ammonia-nitrogen (NH3-N) of 1800-4000 mg/l. VSS was used with the BOD and COD data to simulate the biological activity in the activated sludge. Removal efficiencies > 95-99% for BOD5, VSS, TN and NH3-N were attained. The coupled experimental and simulation results contribute in filling a gap in managing high-strength landfill leachate and providing guidelines for corresponding MBR application. © The Author(s) 2013.

  4. Influence of temperature on carbon and nitrogen dynamics during in situ aeration of aged waste in simulated landfill bioreactors.

    Science.gov (United States)

    Tong, Huanhuan; Yin, Ke; Giannis, Apostolos; Ge, Liya; Wang, Jing-Yuan

    2015-09-01

    The effect of temperature on carbon and nitrogen compounds during in situ aeration of aged waste was investigated in lab-scale simulated landfill bioreactors at 35, 45 and 55 °C, respectively. The bioreactor operated at 55 °C presented the highest carbon mineralization rate in the initial stage, suggesting accelerated biodegradation rates under thermophilic conditions. The nitrogen speciation study indicated that organic nitrogen was the dominant species of total N in aerobic bioreactors due to ammonia removal. Leachate organic nitrogen was further fractionated to elucidate the fate of individual constituent. Detailed investigation revealed the higher bioconversion rates of N-humic and N-fulvic compounds compared to hydrophilic compounds in thermophilic conditions. At the end, waste material in 55 °C bioreactor was richer in highly matured humic substances (HS) verifying the high bioconversion rates.

  5. Reaction mechanisms and rate constants of waste degradation in landfill bioreactor systems with enzymatic-enhancement.

    Science.gov (United States)

    Jayasinghe, P A; Hettiaratchi, J P A; Mehrotra, A K; Kumar, S

    2014-06-01

    Augmenting leachate before recirculation with peroxidase enzymes is a novel method to increase the available carbon, and therefore the food supply to microorganisms at the declining phase of the anaerobic landfill bioreactor operation. In order to optimize the enzyme-catalyzed leachate recirculation process, it is necessary to identify the reaction mechanisms and determine rate constants. This paper presents a kinetic model developed to ascertain the reaction mechanisms and determine the rate constants for enzyme catalyzed anaerobic waste degradation. The maximum rate of reaction (Vmax) for MnP enzyme-catalyzed reactors was 0.076 g(TOC)/g(DS).day. The catalytic turnover number (k(cat)) of the MnP enzyme-catalyzed was 506.7 per day while the rate constant (k) of the un-catalyzed reaction was 0.012 per day.

  6. An experimental study with bioreactor-landfill system%生物反应器填埋场的试验研究

    Institute of Scientific and Technical Information of China (English)

    王君琴; 沈东升

    2003-01-01

    In this study, a methane bioreactor-landfill system was utilized to treat municipal solid waste (MSW). Through analyzing and detecting the pollutant(CODcr) in the bioreactor-landfill system, a simulated mathematic formulaof waste degradation was established. After treated with this system, the CODcr and VFA concentrations in MSW could be decreased from more than 20000 and 7000 mg·L-1 to less than 1500 and 200 mg·L-1, respec-tively.

  7. Liquid balance monitoring inside conventional, Retrofit, and bio-reactor landfill cells

    Energy Technology Data Exchange (ETDEWEB)

    Abichou, Tarek, E-mail: abichou@eng.fsu.edu [Department of Civil and Environmental Engineering, Florida State University, 2525 Pottsdamer Street, Tallahassee, FL 32311 (United States); Barlaz, Morton A. [Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Green, Roger; Hater, Gary [Waste Management Inc., Cincinnati, OH 45211 (United States)

    2013-10-15

    Highlights: • The Retrofit, Control, and As-Built cells received 48, 14, and 213 L Mg{sup −1} (liters of liquids per metric ton of waste). • The leachate collection system yielded 60, 57 and 198 L Mg{sup −1} from the Retrofit, Control, and As-Built cells. • The head on liner in all cells was below regulatory limits. • Measured moisture content of the waste samples was consistent with that calculated from accumulated liquid by balance. • The in-place saturated hydraulic conductivity of the MSW was calculated to be in the range of 10{sup −8} to 10{sup −7} m s{sup −1}. - Abstract: The Outer Loop landfill bioreactor (OLLB) in Louisville, KY, USA has been the site of a study to evaluate long-term bioreactor performance at a full-scale operational landfill. Three types of landfill units were studied including a conventional landfill (Control cell), a new landfill area that had an air addition and recirculation piping network installed as waste was being placed (As-Built cell), and a conventional landfill that was modified to allow for liquids recirculation (Retrofit cell). During the monitoring period, the Retrofit, Control, and As-Built cells received 48, 14, and 213 L Mg{sup −1} (liters of liquids per metric ton of waste), respectively. The leachate collection system yielded 60, 57 and 198 L Mg{sup −1} from the Retrofit, Control, and As-Built cells, respectively. The head on liner in all cells was below regulatory limits. In the Control and As-Built cells, leachate head on liner decreased once waste placement stopped. The measured moisture content of the waste samples was consistent with that calculated from the estimate of accumulated liquid by the liquid balance. Additionally, measurements on excavated solid waste samples revealed large spatial variability in waste moisture content. The degree of saturation in the Control cells decreased from 85% to 75%. The degree of saturation increased from 82% to 83% due to liquids addition in the Retrofit

  8. Designing systems for landfill gas migration control in Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, J. [Camp, Dresser & McKee, Inc., St. Paul, MN (United States)

    1996-11-01

    Camp, Dresser & McKee (CDM) has designed or is in the process of designing several landfill gas migration control systems in Minnesota. The systems are for both active and closed municipal solid waste landfills. The sites have a variety of covers, including geomembranes, clay caps, and non-engineered soil covers. The control system types include small perimeter systems, full-site systems and phased systems for active sites. Figure 1 shows the locations of the systems CDM is working on in Minnesota. This paper focuses on four sites: Oak Grove Landfill, Hopkins Landfill, Washington County Landfill, and Elk River Landfill. Table 1 provides an outline of the individual site characteristics. The first three sites are closed landfills. The Oak Grove Landfill system was designed and constructed for a group of industries responsible for closure and remedial action. The Hopkins and Washington County landfills are under the control of the Minnesota Pollution Control Agency (MPCA). The MPCA enacted a remedial action program at closed landfills, taking over responsibility for long-term liability under the terms of legally binding agreements negotiated with the site owners. The Elk River Landfill is an active, privately-owned facility. The migration problems and solutions developed for these four landfills are generally descriptive of all the landfills CDM is working on in Minnesota. All landfills have unique characteristics requiring site-specific solutions. CDM, after designing a number of migration control systems in Minnesota, is able to provide a generalized description of design options for specific types of sites. This paper discussions design options used to address different cover types, aesthetic needs, and waste depths, and includes a discussion of design needs for cold climates. A brief case history of the Oak Grove Landfill is included.

  9. Start-up of the SHARON and ANAMMOX process in landfill bioreactors using aerobic and anaerobic ammonium oxidising biomass.

    Science.gov (United States)

    Shalini, S Sri; Joseph, Kurian

    2013-12-01

    The main aim of this study is to analyse the feasibility to use aerobic ammonium oxidising bacteria (AOB) and anammox/AnAOB biomass enriched from mined municipal solid waste for in situ SHARON and ANAMMOX processes in laboratory scale landfill bioreactors (LFBR) for ammonia nitrogen removal. For this purpose, three LFBRs were operated as Control (without biomass seed), SHARON (with AOB biomass seed) and ANAMMOX (with anammox biomass seed) for 315 days. Results showed nitrogen loading rate of 1.0 kg N/d was effectively removed in SHARON and ANAMMOX LFBR. In SHARON LFBR, partial nitritation efficiency reached up to 98.5% with AOB population of MPN of 5.1 × 10(6)/mL obtained. ANAMMOX LFBR gave evolution of 95% of nitrogen gas as the end product confirmed the ANAMMOX process. Nitrogen transformations, biomass development and hydrazine and hydroxylamine formation authenticated the enriched AOB and anammox biomass activity in landfill bioreactors.

  10. Effect of leachate recycle and inoculation on microbial characteristics of municipal refuse in landfill bioreactors

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Population development of key groups of anaerobic and aerobic bacteria involved in municipal refuse decomposition under laboratory landfill bioreactors with and without leachate recycle adinoculation was measured since modeling municipal refuse was landfilled in bioreactors for about 210 days. Hydrolytic fermentative bacteria (HFB), hydrogen-producing acetogenic bacteria (HPAB), methane-producing bacteria (MPB), sulfate-reducing bacteria (SRB), anaerobic and aerobic cellulolytic bacteria and denitrabacteria were enumerated by the most probable number technique. The results showed that the dominant microorganismgroups were the methanogenic bacteria including hydrolytic fermentative, hydrogen-producing acetogenic and methane-producing bacteria. They were present in fresh refuse but at low values and positively affected by leachate recycle and refuse inoculation. The amounts of HFB or HPAB in digesters D4 and D5 operated with noculation and leachate recycle reached their maximum values of1010-1012 cells/g dry refuse for HFB or 105-106 cells/g dry refuse for HPAB on day 60, in digester D3 operated with leachate recycle on day 120 for HFB (109 cells/g dry refuse) or on day 90 for HPAB (105 cells/g dry refuse), and in digesters D1 and D2 on day 210 for HFB (109 cells/g dry refuse) or on day 90 for HPAB (104-106 cells/g dry refuse). The population of methane-producing bacteria in digesters D4 and D5 sharply increased on days 60 and 90 respectively, however in igesters D1, D2 and D3 on day 120. Leachate recycle and inoculation changed the cellulolytic microorganisms composition of refuse ecosystem, the higher amounts of anaerobic cellulolytic bacteria were measured in digesters D4 and D5 (107 cells/g dry refuse), followed by digesters D3 (106 cells/g dry refuse), D2 or D1(104 cells/g dry refuse). However, the amounts of aerobic cellulolytic bacteria were much lower than that of anaerobic cellulolytic bacteria. And it was higher in digester D3 than those in digesters D1, D2

  11. Design and validation of a corneal bioreactor.

    Science.gov (United States)

    Leonard, Elissa K; Pai, Vincent H; Amberg, Philip; Gardner, Jens; Orwin, Elizabeth J

    2012-12-01

    Mechanical strain is an important signal that influences the behavior and properties of cells in a wide variety of tissues. Physiologically similar mechanical strain can revert cultured cells to a more normal phenotype. Here, we have demonstrated that 3% equibiaxial (EB) and uniaxial strains confer favorable protein expression in cultured rabbit corneal fibroblasts (RCFs), with approximately 35% and 65% reduction in expression of α-smooth muscle actin (α-SMA), respectively. We have designed a novel bioreactor that is capable of imparting up to 7% EB strain and up to 6% EB strain using a cornea-shaped post. Additional features of the bioreactor include the application of shear stress to cells in culture and the ability to image cells using optical coherence microscopy (OCM) without being removed from the system. Copyright © 2012 Wiley Periodicals, Inc.

  12. Bioreactor and process design for biohydrogen production.

    Science.gov (United States)

    Show, Kuan-Yeow; Lee, Duu-Jong; Chang, Jo-Shu

    2011-09-01

    Biohydrogen is regarded as an attractive future clean energy carrier due to its high energy content and environmental-friendly conversion. It has the potential for renewable biofuel to replace current hydrogen production which rely heavily on fossil fuels. While biohydrogen production is still in the early stage of development, there have been a variety of laboratory- and pilot-scale systems developed with promising potential. This work presents a review of advances in bioreactor and bioprocess design for biohydrogen production. The state-of-the art of biohydrogen production is discussed emphasizing on production pathways, factors affecting biohydrogen production, as well as bioreactor configuration and operation. Challenges and prospects of biohydrogen production are also outlined.

  13. N₂O emission from a combined ex-situ nitrification and in-situ denitrification bioreactor landfill.

    Science.gov (United States)

    Wang, Ya-nan; Sun, Ying-jie; Wang, Lei; Sun, Xiao-jie; Wu, Hao; Bian, Rong-xing; Li, Jing-jing

    2014-11-01

    A combined process comprised of ex-situ nitrification in an aged refuse bioreactor (designated as A bioreactor) and in-situ denitrification in a fresh refuse bioreactor (designated as F bioreactor) was constructed for investigating N2O emission during the stabilization of municipal solid waste (MSW). The results showed that N2O concentration in the F bioreactor varied from undetectable to about 130 ppm, while it was much higher in the A bioreactor with the concentration varying from undetectable to about 900 ppm. The greatly differences of continuous monitoring of N2O emission after leachate cross recirculation in each period were primarily attributed to the stabilization degree of MSW. Moreover, the variation of N2O concentration was closely related to the leachate quality in both bioreactors and it was mainly affected by the COD and COD/TN ratio of leachate from the F bioreactor, as well as the DO, ORP, and NO3(-)-N of leachate from the A bioreactor.

  14. [Analysis on Diversity of Denitrifying Microorganisms in Sequential Batch Bioreactor Landfill].

    Science.gov (United States)

    Li, Wei-Hua; Sun, Ying-Jie; Liu, Zi-Liang; Ma, Qiang; Yang, Qiang

    2016-01-15

    A denitrification functional microorganism gene clone library (amoA, nosZ) and the PCR-RFLP technology was constructed to investigate the microbial diversity of denitrifying microorganisms in the late period of stabilization of sequential batch bioreactor landfill. The results indicated that: the bacterial diversity of ammonia oxidizing bacteria in the aged refuse reactor was very high, and most of them were unknown groups, also, all bacteria were unculturable or had not been isolated. The phylogenetic analysis suggested that the dominant ammonia oxidizing bacteria were presumably Nitrosomonas of 6-Proteobacteria. The diversity of denitrifying bacteria in fresh refuse reactor was abundant, which mainly included Thauera and Thiobacillus of 6-Proteobacteria. As Thauera sp. has the denitrification characteristics under the condition of aerobic while Thiobacillus denitrificans has the autotrophic denitrification characteristics, it was speculated that aerobic denitrification and autotrophic denitrification might be the main pathways for nitrogen removal in the fresh refuse reactor at the late period of stabilization. Additionally, another group in the gene clone library of denitrifying bacteria may be classified as Bradyrhizobiaceae of alpha-Proteobacteria.

  15. Comparative modeling of biological nutrient removal from landfill leachate using a circulating fluidized bed bioreactor (CFBBR).

    Science.gov (United States)

    Eldyasti, Ahmed; Andalib, Mehran; Hafez, Hisham; Nakhla, George; Zhu, Jesse

    2011-03-15

    Steady state operational data from a pilot scale circulating fluidized bed bioreactor (CFBBR) during biological treatment of landfill leachate, at empty bed contact times (EBCTs) of 0.49, and 0.41 d and volumetric nutrients loading rates of 2.2-2.6 kg COD/(m(3)d), 0.7-0.8 kg N/(m(3)d), and 0.014-0.016 kg P/(m(3)d), was used to calibrate and compare developed process models in BioWin(®) and AQUIFAS(®). BioWin(®) and AQUIFAS(®) were both capable of predicting most of the performance parameters such as effluent TKN, NH(4)-N, NO(3)-N, TP, PO(4)-P, TSS, and VSS with an average percentage error (APE) of 0-20%. BioWin(®) underpredicted the effluent BOD and SBOD values for various runs by 80% while AQUIFAS(®) predicted effluent BOD and SBOD with an APE of 50%. Although both calibrated models, confirmed the advantages of the CFBBR technology in treating the leachate of high volumetric loading and low biomass yields due to the long solid retention time (SRT), both BioWin(®) and AQUIFAS(®) predicted the total biomass and SRT of CFBBR based on active biomass only, whereas in the CFBBR runs both active as well as inactive biomass accumulated.

  16. Degradation of municipal solid waste in simulated landfill bioreactors under aerobic conditions.

    Science.gov (United States)

    Slezak, Radoslaw; Krzystek, Liliana; Ledakowicz, Stanislaw

    2015-09-01

    In this study the municipal solid waste degradation processes in simulated landfill bioreactors under aerobic and anaerobic conditions is investigated. The effect of waste aeration on the dynamics of the aerobic degradation processes in lysimeters as well as during anaerobic processes after completion of aeration is presented. The results are compared with the anaerobic degradation process to determine the stabilization stage of waste in both experimental modes. The experiments in aerobic lysimeters were carried out at small aeration rate (4.41⋅10(-3)lmin(-1)kg(-1)) and for two recirculation rates (24.9 and 1.58lm(-3)d(-1)). The change of leachate and formed gases composition showed that the application of even a small aeration rate favored the degradation of organic matter. The amount of CO2 and CH4 released from anaerobic lysimeter was about 5 times lower than that from the aerobic lysimeters. Better stabilization of the waste was obtained in the aerobic lysimeter with small recirculation, from which the amount of CO2 produced was larger by about 19% in comparison with that from the aerobic lysimeter with large leachate recirculation.

  17. Landfills

    Data.gov (United States)

    Vermont Center for Geographic Information — This data set defines both current and historic landfills/waste disposal storage sites for the State of Vermont. Historic landfills were identified with the...

  18. Bioreactor Scalability: Laboratory-Scale Bioreactor Design Influences Performance, Ecology, and Community Physiology in Expanded Granular Sludge Bed Bioreactors.

    Science.gov (United States)

    Connelly, Stephanie; Shin, Seung G; Dillon, Robert J; Ijaz, Umer Z; Quince, Christopher; Sloan, William T; Collins, Gavin

    2017-01-01

    Studies investigating the feasibility of new, or improved, biotechnologies, such as wastewater treatment digesters, inevitably start with laboratory-scale trials. However, it is rarely determined whether laboratory-scale results reflect full-scale performance or microbial ecology. The Expanded Granular Sludge Bed (EGSB) bioreactor, which is a high-rate anaerobic digester configuration, was used as a model to address that knowledge gap in this study. Two laboratory-scale idealizations of the EGSB-a one-dimensional and a three- dimensional scale-down of a full-scale design-were built and operated in triplicate under near-identical conditions to a full-scale EGSB. The laboratory-scale bioreactors were seeded using biomass obtained from the full-scale bioreactor, and, spent water from the distillation of whisky from maize was applied as substrate at both scales. Over 70 days, bioreactor performance, microbial ecology, and microbial community physiology were monitored at various depths in the sludge-beds using 16S rRNA gene sequencing (V4 region), specific methanogenic activity (SMA) assays, and a range of physical and chemical monitoring methods. SMA assays indicated dominance of the hydrogenotrophic pathway at full-scale whilst a more balanced activity profile developed during the laboratory-scale trials. At each scale, Methanobacterium was the dominant methanogenic genus present. Bioreactor performance overall was better at laboratory-scale than full-scale. We observed that bioreactor design at laboratory-scale significantly influenced spatial distribution of microbial community physiology and taxonomy in the bioreactor sludge-bed, with 1-D bioreactor types promoting stratification of each. In the 1-D laboratory bioreactors, increased abundance of Firmicutes was associated with both granule position in the sludge bed and increased activity against acetate and ethanol as substrates. We further observed that stratification in the sludge-bed in 1-D laboratory

  19. Protozoan indicators and extracellular polymeric substances alterations in an intermittently aerated membrane bioreactor treating mature landfill leachate.

    Science.gov (United States)

    Remmas, Nikolaos; Melidis, Paraschos; Paschos, Georgios; Statiris, Evangelos; Ntougias, Spyridon

    2017-01-01

    A membrane bioreactor was operated under intermittent aeration and various organic loading rates (OLR: 0.070, 0.159 and 0.291 g COD L(-1) d(-1)) to remove carbon and nitrogen from mature landfill leachate, where external carbon source (glycerol) addition resulted in effective nitrate removal. A relative increase in soluble microbial product (SMP) over extracellular polymeric substances (EPS) was observed at the highest OLR and glycerol addition, whereas no membrane biofouling occurred. SMP (proteins and carbohydrates) and carbohydrate EPS correlated positively and negatively, respectively, with suspended solids and transmembrane pressure (TMP). Moreover, proteinous SMP significantly correlated with carbon and nitrogen load. Principal component analysis also revealed the influence of leachate organic and nitrogen content on biomass production, TMP and sessile ciliate densities. Although filamentous index (FI) was sustained at high levels (3-4), with Haliscomenobacter hydrossis being the main filamentous bacterium identified, no bulking phenomena occurred. High glycerol addition resulted in a rapid increase in sessile ciliate population. Increased Epistylis and Vorticella microstoma population was detected by microscopic examination during high glycerol addition, while a remarkable Rhogostoma population (supergroup Rhizaria) was identified by molecular techniques. The contribution of Rhizaria in nitrogen processes may lead to the dominance of Rhogostoma during landfill leachate treatment.

  20. Removal of organic micro-pollutants from solid waste landfill leachate in membrane bioreactor operated without excess sludge discharge.

    Science.gov (United States)

    Boonyaroj, V; Chiemchaisri, C; Chiemchaisri, W; Yamamoto, K

    2012-01-01

    Two-stage membrane bioreactor (MBR) system was applied to the treatment of landfill leachate from a solid waste disposal site in Thailand. The first stage anoxic reactor was equipped with an inclined tube module for sludge separation. It was followed by an aerobic stage with a hollow fiber membrane module for solid liquid separation. Mixed liquor sludge from the aerobic reactor was re-circulated back to anoxic reactor in order to maintain constant mixed liquor suspended solids (MLSS) concentration in the aerobic reactor. The removal of micro-pollutants from landfill leachate along the treatment period of 300 days was monitored. The results indicated that two-stage MBRs could remove biochemical oxygen demand (BOD), chemical oxygen demand (COD) and NH(4)(+) by 97, 87 and 91% at steady operating condition. Meanwhile organic micro-pollutant removals were 50-76%. The removal efficiencies varied according to the hydrophobic characteristic of compounds but they were improved during long-term MBR operation without sludge discharge.

  1. Occurrence and removal of organic micropollutants in the treatment of landfill leachate by combined anaerobic-membrane bioreactor technology

    Institute of Scientific and Technical Information of China (English)

    XU Yiping; ZHOU Yiqi; WANG Donghong; CHEN Shaohua; LIU Junxin; WANG Zijian

    2008-01-01

    Organic micropollutants, with high toxicity and environmental concern, are present in the landfill leachate at much lower levels than total organic constituents (chemical oxygen demand (COD), biochemical oxygen demand (BOD), or total organic carbon (TOC)), and few has been known for their behaviors in different treatment processes. In this study, occurrence and removal of 17 organochlorine pesticides (OCPs), 16 polycyelic aromatic hydrocarbons (PAHs), and technical 4-nonylphenol (4-NP) in landfill leachate in a combined anaerobic-membrane bioreactor (MBR) were investigated. Chemical analyses were performed in leachates sampled from different treatment processes, using solid-phase extraction and gas chromatography with electron capture detector and mass spectrometry.Concentrations of OCPs, PAHs, and 4-NP in the raw leachate were detected within the range from ND (not detected) to 595.2 ng/L,which were as low as only 10-7-10-5 percentage of TOC (at the concentration of 2,962 mg/L). The removal of 4-NP was mainly established in the MBR process, in agreement with removals of COD, BOD, and TOC. However, the removals of OCPs and PAHs were different, mainly achieved in the anaerobic process. High removal efliciencies of both total organic constituents and organic micropollutants could be achieved by the combined anaerobic-MBR technology. The removal efficiencies of total organic constituents were in the order of BOD (99%) > COD (89%) > TOC (87%), whereas the removal efficiencies of investigated organic micropollutants were as follows: OCPs (94%) > 4-NP (77%) > PAHs (59%).

  2. [Technological characteristics of bioreactor landfill with aeration in the upper layer].

    Science.gov (United States)

    Tian, Ying; Wang, Shen; Xu, Qi-Yong

    2014-11-01

    In order to study the effects of upper-layer aerobic pretreatment in bioreactors on refuse degradation, leachate condition and methane production, two simulated columns were constructed, including traditional anaerobic bioreactor A1 and hybrid bioreactor C1 with aeration pretreatment in the upper layer. Results indicated that A1 was seriously inhibited by the accumulation of volatile fatty acids (VFA) with nearly no methane production and slower settlements. At the end of operations, refuse in A1 only deposited 5.4 cm which was less than half of that in C1. And up to 70 000 mg x L(-1) COD and 30 000 mg x L(-1) VFA could be monitored in the leachate. On the contrary, aerobic pretreatment effectively improved the removal of high VFA concentrations and remarkably accelerated the degradation rate. In bioreactor C1, COD and VFA concentrations were reduced to less than 14000 mg x L(-1) and 8900 mg x L(-1) at the end of the experiment, respectively. And about 61 976 mL methane gases were produced since aeration ceased on day 60 with its methane recovery efficiency rising to over 95%. However, the performance of hybrid bioreactors was still closely related to its operation conditions, such as aeration supply and leachate recirculation. Therefore, in order to guarantee better performance, appropriate aeration and leachate operations need to be provided.

  3. Hairy root culture: bioreactor design and process intensification.

    Science.gov (United States)

    Stiles, Amanda R; Liu, Chun-Zhao

    2013-01-01

    The cultivation of hairy roots for the production of secondary metabolites offers numerous advantages; hairy roots have a fast growth rate, are genetically stable, and are relatively simple to maintain in phytohormone free media. Hairy roots provide a continuous source of secondary metabolites, and are useful for the production of chemicals for pharmaceuticals, cosmetics, and food additives. In order for hairy roots to be utilized on a commercial scale, it is necessary to scale-up their production. Over the last several decades, significant research has been conducted on the cultivation of hairy roots in various types of bioreactor systems. In this review, we discuss the advantages and disadvantages of various bioreactor systems, the major factors related to large-scale bioreactor cultures, process intensification technologies and overview the mathematical models and computer-aided methods that have been utilized for bioreactor design and development.

  4. Permitting of Landfill Bioreactor Operations: Ten Years after the RD&D Rule

    Science.gov (United States)

    Prior to promulgation of the Rule, there were approximately 20 full-scale bioreactor projects in North America, including one in Canada. Of these, six were permitted by EPA (four Project XL sites and two projects listed separately under a cooperative research agreement at the Ou...

  5. Permitting of Landfill Bioreactor Operations: Ten Years after the RD&D Rule

    Science.gov (United States)

    Prior to promulgation of the Rule, there were approximately 20 full-scale bioreactor projects in North America, including one in Canada. Of these, six were permitted by EPA (four Project XL sites and two projects listed separately under a cooperative research agreement at the Ou...

  6. Bioreactor technology in marine microbiology: from design to future application.

    Science.gov (United States)

    Zhang, Yu; Arends, Jan B A; Van de Wiele, Tom; Boon, Nico

    2011-01-01

    Marine micro-organisms have been playing highly diverse roles over evolutionary time: they have defined the chemistry of the oceans and atmosphere. During the last decades, the bioreactors with novel designs have become an important tool to study marine microbiology and ecology in terms of: marine microorganism cultivation and deep-sea bioprocess characterization; unique bio-chemical product formation and intensification; marine waste treatment and clean energy generation. In this review we briefly summarize the current status of the bioreactor technology applied in marine microbiology and the critical parameters to take into account during the reactor design. Furthermore, when we look at the growing population, as well as, the pollution in the coastal areas of the world, it is urgent to find sustainable practices that beneficially stimulate both the economy and the natural environment. Here we outlook a few possibilities where innovative bioreactor technology can be applied to enhance energy generation and food production without harming the local marine ecosystem.

  7. Effect of leachate recycling and inoculation on the biochemical characteristics of municipal refuse in landfill bioreactors

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Activity development of key groups of enzymes involved in municipal refuse decomposition was measured in laboratory landfill hioreactors with and without leachate recycling and inoculation for about 210 days.The results showed that the enzymes (amylase,protease,cellulase,lipase and pectinase ) were present in fresh refuse but at low values and positively affected hy leachate recycling and refuse inoculation.The total average of cellulase activity in digesters D3 operated with leachate recycling but no inoculation,D4 and D5 operated with leachate recycling and inoculation was much higher than that in digesters D1 and D2 without leachate recycling and inoculation by 88%-127%,117%-162% and 64%-98%.The total average of protease activity was higher in digester D4 than that in digesters D1,D2,D3and D5 by 63%,39%,24% and 24%,respectively,and the positive effect of leachate recycli.ng and inoculation on protease activity of landfilled refuse mainly was at the first two months.The total average of amylase activity was higher in digesters D3,D4 and D5 than that in digesters D1 and D2 by 83%-132%,96%-148% and 81%-129%.During the early phase of incubation,the stimulatory effect of inoculation on lipase activity was measured,but refuse moisture was the main factor affecting lipase activity of landfilled refuse.The inoculation,initial and continuous inoculation of microorganisms existing in leachate,was the mainly stimulatory factor affecting pectinase activity of landfilled refuse.

  8. Bioreactor design for continuous dark fermentative hydrogen production.

    Science.gov (United States)

    Jung, Kyung-Won; Kim, Dong-Hoon; Kim, Sang-Hyoun; Shin, Hang-Sik

    2011-09-01

    Dark fermentative H2 production (DFHP) has received increasing attention in recent years due to its high H2 production rate (HPR) as well as the versatility of the substrates used in the process. For most studies in this field, batch reactors have been applied due to their simple operation and efficient control; however, continuous DFHP operation is necessary from economical and practical points of view. Continuous systems can be classified into two categories, suspended and immobilized bioreactors, according to the life forms of H2 producing bacteria (HPB) used in the reactor. This paper reviews operational parameters for bioreactor design including pH, temperature, hydraulic retention time (HRT), and H2 partial pressure. Also, in this review, various bioreactor configurations and performance parameters including H2 yield (HY), HPR, and specific H2 production rate (SHPR) are evaluated and presented.

  9. International training seminar: high training on sanitary landfills design, Madrid 7-11, April 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    The seminar on design of sanitary landfills was articulated in 5 sessions: 1.- Design of sanitary landfills depending on the quality of wastes. 2.- Legal, techniques and administrative aspects of management. 3.- Geotechniques studies 4.- Biogas 5.- Environmental impact of sanitary landfills.

  10. On adaptive optimal input design: A bioreactor case study

    NARCIS (Netherlands)

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

    2006-01-01

    The problem of optimal input design (OID) for a fed-batch bioreactor case study is solved recursively. Here an adaptive receding horizon optimal control problem, involving the so-called E-criterion, is solved on-line, using the current estimate of the parameter vector at each sample instant {tk, k =

  11. Intelligent Bioreactor Management Information System (IBM-IS) for Mitigation of Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Paul Imhoff; Ramin Yazdani; Don Augenstein; Harold Bentley; Pei Chiu

    2010-04-30

    Methane is an important contributor to global warming with a total climate forcing estimated to be close to 20% that of carbon dioxide (CO2) over the past two decades. The largest anthropogenic source of methane in the US is 'conventional' landfills, which account for over 30% of anthropogenic emissions. While controlling greenhouse gas emissions must necessarily focus on large CO2 sources, attention to reducing CH4 emissions from landfills can result in significant reductions in greenhouse gas emissions at low cost. For example, the use of 'controlled' or bioreactor landfilling has been estimated to reduce annual US greenhouse emissions by about 15-30 million tons of CO2 carbon (equivalent) at costs between $3-13/ton carbon. In this project we developed or advanced new management approaches, landfill designs, and landfill operating procedures for bioreactor landfills. These advances are needed to address lingering concerns about bioreactor landfills (e.g., efficient collection of increased CH4 generation) in the waste management industry, concerns that hamper bioreactor implementation and the consequent reductions in CH4 emissions. Collectively, the advances described in this report should result in better control of bioreactor landfills and reductions in CH4 emissions. Several advances are important components of an Intelligent Bioreactor Management Information System (IBM-IS).

  12. Post-treatment of the permeate of a submerged anaerobic membrane bioreactor (SAMBR) treating landfill leachate.

    Science.gov (United States)

    Trzcinski, Antoine P; Ofoegbu, Nkechi; Stuckey, David C

    2011-01-01

    In this study, various methods were compared to reduce the Chemical Oxygen Demand (COD) content of stabilised leachate from a Submerged Anaerobic Membrane Bioreactor (SAMBR). It was found that Powdered Activated Carbon (PAC) resulted in greater COD removals (84 %) than Granular Activated Carbon (GAC-80 %), an ultrafiltration membrane of 1kDa (75 %), coagulation-flocculation with FeCl(3) and polyelectrolyte (45 %), FeCl(3) alone (32 %), and polymeric adsorbents such as XAD7HP (46 %) and XAD4 (32 %). Results obtained on the PAC and GAC had a similar adsorption efficiency of about 60 % COD removal, followed by XAD7HP (48 %), XAD4 (27 %) and then FeCl(3) (23 %). The post-treatment sequence UF+GAC would result in a final effluent with less than 100 mg COD/L. Size Exclusion Chromatography (SEC) revealed that the extent of adsorption of low MW compounds onto PAC was limited due to low MW hydrophilic compounds, whereas the kinetics of PAC adsorption depended mainly on the adsorption of high MW aromatics.

  13. STUDI PENGARUH AERASI DAN RESIRKULASI LINDI TERHADAP LAJU PROSES DEGRADASI SAMPAH PADA BIOREACTOR LANDFILL

    Directory of Open Access Journals (Sweden)

    Syafrudin Syafrudin

    2012-02-01

    Full Text Available On the conventional landfill, the waste degradation requires a lot of time to make it through and it produces amethane gasfrom a anaerobic which could be dangerous if there is not an optimal processing. On this research,the writer uses 7 experimental reactors, 6 reactors given aeration treatments and leachate recirculation. Thevariations which have done in the research is leachate recirculation debit, namely (10 and 15 ml/minutes andcontinual lacheate’s flowing system and aeration variation, namely (3, 2, and 1ml/minutes everyday. Theparameter which is measured is the reduction of waste volume, temperature, PH, BOD and COD for weeklyanalysis. The results of the analysis are that the aeration of 1 ml/minutes with leachate resirculation of 15ml/minutes is the best of aeration condition and it can increase the settlement process and reduction of BOD andCOD concentration in a short time of leachate. This reactor can increase the volume reduction as much as 14,14% in six week and it is bigger than control reactor. The concentration reduction of BOD is from 718, 24 mg/lbecomes 88,44 mg/l and the reduction of COD is from 1285,58 mg/l becomes 893,44 mg/l

  14. Targeted modification of organic components of municipal solid waste by short-term pre-aeration and its enhancement on anaerobic degradation in simulated landfill bioreactors.

    Science.gov (United States)

    Ni, Zhe; Liu, Jianguo; Girotto, Francesca; Cossu, Raffaello; Qi, Guangxia

    2016-09-01

    Pre-aeration is effective on regulating subsequent anaerobic degradation of municipal solid waste (MSW) with high organic fractions during landfilling. The strength of pre-aeration should be optimized to intentionally remove some easily biodegradable fractions while conserve bio-methane potential as much as possible. This study investigates the evolution of organic components in MSW during 2-14days pre-aeration process and its impacts on subsequent anaerobic degradation in simulated landfill bioreactors. Results showed that a 6-day pre-aeration enabled to develop a thermophilic stage, which significantly accelerated biodegradation of organics except lignocelluloses, with removal rates of 42.8%, 76.7% and 25.1% for proteins, carbohydrates and lipids, respectively. Particularly, ammonia from accelerated ammonification in the thermophilic stage neutralized VFAs generated from anaerobic landfilling. As a result, the MSW with 6-day pre-aeration obtained the highest methane yield 123.4NL/kg dry matter. Therefore, it is recommended to interrupt pre-aeration before its cooling stage to switch to anaerobic landfilling.

  15. Bioreactor technology in marine microbiology: From design to future application

    OpenAIRE

    Zhang, Yu; Arends, Jan B.A.; van de Wiele, Tom; Boon, Nico

    2011-01-01

    Marine micro-organisms have been playing highly diverse roles over evolutionary time: they have defined the chemistry of the oceans and atmosphere. During the last decades, the bioreactors with novel designs have become an important tool to study marine microbiology and ecology in terms of: marine microorganism cultivation and deep-sea bioprocess characterization; unique bio-chemical product formation and intensification; marine waste treatment and clean energy generation. In this review we b...

  16. Pharmaceuticals and personal care products in the leachates from a typical landfill reservoir of municipal solid waste in Shanghai, China: Occurrence and removal by a full-scale membrane bioreactor.

    Science.gov (United States)

    Sui, Qian; Zhao, Wentao; Cao, Xuqi; Lu, Shuguang; Qiu, Zhaofu; Gu, Xiaogang; Yu, Gang

    2017-02-05

    Knowledge on the pharmaceuticals and personal care products (PPCPs) in landfill leachates, which are an important source of PPCPs in the environment, was very limited. Hence, four sampling campaigns were conducted to determine eighteen PPCPs in the landfill leachates from a landfill reservoir in Shanghai. Five of the target PPCPs were first included in a landfill leachate study. Additionally, their removal from landfill leachates by a full-scale membrane bioreactor (MBR) was illustrated. The results showed fourteen out of eighteen PPCPs were detectable in at least one sampling campaign and achieved individual concentrations ranging from 0.39 to 349μg/L in the landfill leachates. Some PPCPs exhibited higher contamination levels than those reported in other countries. Good removal of PPCPs by MBR led to a largely reduced contamination level (landfill leachates, which was, however, still much higher than those in municipal wastewaters in Shanghai. To the best of our knowledge, this is the first report on the removal of PPCPs in landfill leachates. The findings emphasized the necessity to further study the PPCPs in the landfill leachates in China and the requirement to enhance their removal in the landfill leachates. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Design of microfluidic bioreactors using topology optimization

    DEFF Research Database (Denmark)

    Okkels, Fridolin; Bruus, Henrik

    2007-01-01

    We address the design of optimal reactors for supporting biological cultures using the method of topology optimization. For some years this method have been used to design various optimal microfluidic devices.1-4 We apply this method to distribute optimally biologic cultures within a flow of nutr...

  18. Bioreactor design for photofermentative hydrogen production.

    Science.gov (United States)

    Uyar, Basar

    2016-09-01

    Hydrogen will become a significant fuel in the near future. Photofermentative production of hydrogen is a promising and sustainable process. The design, construction and successful operation of the photobioreactors are of critical importance for photofermentative hydrogen production and became a major field of research where novel technologies are developed and adapted frequently. This paper gives an overview of the design aspects related to photobioreactors giving particular attention to design limitations, construction material, type, operating mode and scale-up. Sub-components of the overall system setup such as mixing, temperature control and hydrogen collection are also discussed. Recent achievements in the photobioreactor technologies are described.

  19. Rational design approach for landfill liner protective soil cover

    Energy Technology Data Exchange (ETDEWEB)

    Ruetten, M.G. [STS Consultants Ltd., Green Bay, WI (United States); Bandi, S.R. [Rust Environment & Infrastructure, Livonia, MI (United States); Reddy, K.R. [Univ. of Illinois, Chicago, IL (United States)

    1995-12-31

    This paper presents a rational approach for designing protective soil cover for landfill geomembrane liners in order to prevent damage to the liners. The present practice involves using a combination of geotextile and soil layer as protective cover. The geotextile is placed directly over the geomembrane and then a protective soil is placed on the geotextile. The protective soil layer generally consists of a free-draining granular soil which also serves as a drainage layer for the leachate collection and removal system. The degree of protection offered to the geomembrane depends on the type of geotextile, and the composition and thickness of the protective soil used.

  20. Landfilling: Hydrology

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Beaven, R.

    2011-01-01

    Landfill hydrology deals with the presence and movement of water through a landfill. The main objective in landfill hydrology is usually to predict leachate generation, but the presence and movement of water in a landfill also affect the degradation of the waste, the leaching of pollutants...... and the geotechnical stability of the fill. Understanding landfill hydrology is thus important for many aspects of landfill, in particular siting, design and operation. The objective of this chapter is to give a basic understanding of the hydrology of landfills, and to present ways to estimate leachate quantities......-circuiting. In the final section different existing hydrological models for landfills are presented with a special focus on the HELP model. This model is the most widely used tool for the prediction of leachate quantities in landfills, and for the sizing of leachate control and management infrastructure....

  1. Landfilling: Hydrology

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Beaven, R.

    2011-01-01

    Landfill hydrology deals with the presence and movement of water through a landfill. The main objective in landfill hydrology is usually to predict leachate generation, but the presence and movement of water in a landfill also affect the degradation of the waste, the leaching of pollutants...... and the geotechnical stability of the fill. Understanding landfill hydrology is thus important for many aspects of landfill, in particular siting, design and operation. The objective of this chapter is to give a basic understanding of the hydrology of landfills, and to present ways to estimate leachate quantities......-circuiting. In the final section different existing hydrological models for landfills are presented with a special focus on the HELP model. This model is the most widely used tool for the prediction of leachate quantities in landfills, and for the sizing of leachate control and management infrastructure....

  2. Heavy metal leaching from aerobic and anaerobic landfill bioreactors of co-disposed municipal solid waste incineration bottom ash and shredded low-organic residues.

    Science.gov (United States)

    Inanc, Bulent; Inoue, Yuzo; Yamada, Masato; Ono, Yusaku; Nagamori, Masanao

    2007-03-22

    In this study, heavy metal leaching from aerobic and anaerobic landfill bioreactor test cells for co-disposed municipal solid waste incineration (MSWI) bottom ash and shredded low-organic residues has been investigated. Test cells were operated for 1 year. Heavy metals which were comparatively higher in leachate of aerobic cell were copper (Cu), lead (Pb), boron (B), zinc (Zn), manganese (Mn) and iron (Fe), and those apparently lower were aluminum (Al), arsenic (As), molybdenum (Mo), and vanadium (V). However, no significant release of heavy metals under aerobic conditions was observed compared to anaerobic and control cells. Furthermore, there was no meaningful correlation between oxidation-reduction potential (ORP) and heavy metal concentrations in the leachates although some researchers speculate that aeration may result in excessive heavy metal leaching. No meaningful correlation between dissolved organic carbon (DOC) and leaching of Cu and Pb was another interesting observation. The only heavy metal that exceeded the state discharge limits (10mg/l, to be enforced after April 2005) in the aerobic cell leachate samples was boron and there was no correlation between boron leaching and ORP. Higher B levels in aerobic cell should be due to comparatively lower pH values in this cell. However, it is anticipated that this slightly increased concentrations of B (maximum 25mg/l) will not create a risk for bioreactor operation; rather it should be beneficial for long-term stability of the landfill through faster washout. It was concluded that aerobization of landfills of heavy metal rich MSWI bottom ash and shredded residues is possible with no dramatic increase in heavy metals in the leachate.

  3. Case study of an MBT plant producing SRF for cement kiln co-combustion, coupled with a bioreactor landfill for process residues.

    Science.gov (United States)

    Grosso, Mario; Dellavedova, Stefano; Rigamonti, Lucia; Scotti, Sergio

    2016-01-01

    The paper describes the performances of the energy recovery pathway from the residual waste based on the production of a Solid Recovered Fuel (SRF) to be exploited via co-combustion in a cement kiln. The SRF is produced in a single stream Mechanical-Biological Treatment plant, where bio-drying of the waste is followed by mechanical refining in order to fulfil the quality requirements by the cement kilns. Peculiar of this MBT is the fact that sorting residues are disposed in a nearby landfill, managed according to a bioreactor approach, where landfill gas is collected for electric energy recovery. A detailed mass and energy balance of the system is presented based on one year operational data, followed by its Life Cycle Assessment. Results show that the system is energetically and environmentally effective, with most of the impacts being more than compensated by the savings of materials and energy. Major role in determining such outcome is the displacement of petcoke in the cement kiln, both in terms of its fossil CO2 emissions and of its life cycle impacts, including the trans-oceanic transport. To check the robustness of the results, two sensitivity analyses are performed on the landfill gas collection efficiency and on the avoided electric energy mix.

  4. BIOREACTOR ECONOMICS, SIZE AND TIME OF OPERATION (BEST) COMPUTER SIMULATOR FOR DESIGNING SULFATE-REDUCING BACTERIA FIELD BIOREACTORS

    Science.gov (United States)

    BEST (bioreactor economics, size and time of operation) is an Excel™ spreadsheet-based model that is used in conjunction with the public domain geochemical modeling software, PHREEQCI. The BEST model is used in the design process of sulfate-reducing bacteria (SRB) field bioreacto...

  5. Consecutive anaerobic-aerobic treatment of the organic fraction of municipal solid waste and lignocellulosic materials in laboratory-scale landfill-bioreactors.

    Science.gov (United States)

    Pellera, Frantseska-Maria; Pasparakis, Emmanouil; Gidarakos, Evangelos

    2016-10-01

    The scope of this study is to evaluate the use of laboratory-scale landfill-bioreactors, operated consecutively under anaerobic and aerobic conditions, for the combined treatment of the organic fraction of municipal solid waste (OFMSW) with two different co-substrates of lignocellulosic nature, namely green waste (GW) and dried olive pomace (DOP). According to the results such a system would represent a promising option for eventual larger scale applications. Similar variation patterns among bioreactors indicate a relatively defined sequence of processes. Initially operating the systems under anaerobic conditions would allow energetic exploitation of the substrates, while the implementation of a leachate treatment system ultimately aiming at nutrient recovery, especially during the anaerobic phase, could be a profitable option for the whole system, due to the high organic load that characterizes this effluent. In order to improve the overall effectiveness of such a system, measures towards enhancing methane contents of produced biogas, such as substrate pretreatment, should be investigated. Moreover, the subsequent aerobic phase should have the goal of stabilizing the residual materials and finally obtain an end material eventually suitable for other purposes.

  6. DESIGNING SULFATE-REDUCING BACTERIA FIELD BIOREACTORS USING THE BEST MODEL

    Science.gov (United States)

    BEST (bioreactor economics, size and time of operation) is a spreadsheet-based model that is used in conjunction with a public domain computer software package, PHREEQCI. BEST is intended to be used in the design process of sulfate-reducing bacteria (SRB)field bioreactors to pas...

  7. Design and Performance of an Automated Bioreactor for Cell Culture Experiments in a Microgravity Environment

    Science.gov (United States)

    Kim, Youn-Kyu; Park, Seul-Hyun; Lee, Joo-Hee; Choi, Gi-Hyuk

    2015-03-01

    In this paper, we describe the development of a bioreactor for a cell-culture experiment on the International Space Station (ISS). The bioreactor is an experimental device for culturing mouse muscle cells in a microgravity environment. The purpose of the experiment was to assess the impact of microgravity on the muscles to address the possibility of longterm human residence in space. After investigation of previously developed bioreactors, and analysis of the requirements for microgravity cell culture experiments, a bioreactor design is herein proposed that is able to automatically culture 32 samples simultaneously. This reactor design is capable of automatic control of temperature, humidity, and culture-medium injection rate; and satisfies the interface requirements of the ISS. Since bioreactors are vulnerable to cell contamination, the medium-circulation modules were designed to be a completely replaceable, in order to reuse the bioreactor after each experiment. The bioreactor control system is designed to circulate culture media to 32 culture chambers at a maximum speed of 1 ml/min, to maintain the temperature of the reactor at 36°C, and to keep the relative humidity of the reactor above 70%. Because bubbles in the culture media negatively affect cell culture, a de-bubbler unit was provided to eliminate such bubbles. A working model of the reactor was built according to the new design, to verify its performance, and was used to perform a cell culture experiment that confirmed the feasibility of this device.

  8. 生物反应器填埋场中水平沟回灌渗滤液非饱和-饱和渗流分析%Unsaturated-saturated seepage analysis for leachate recirculation using horizontal trenches in bioreactor landfills

    Institute of Scientific and Technical Information of China (English)

    冯世进; 张旭

    2013-01-01

    The horizontal trench is one of the main methods which are available to recirculate leachates.To study the unsaturated-saturated seepage laws during leachate recirculation process,different flow control equations are used for the saturated/unsaturated zones in bioreactor landfills.The saturated Richards' equation is adopted as the flow governing equation in the saturated area of the waste mass.For the unsaturated area of the waste mass,based on the law of conservation of mass,the modified Darcy's law and the Elagroudy's settlement model,a new flow governing equation considering solid waste settlement is developed.Based on the two-dimensional saturated/unsaturated model which has been developed considering solid waste settlement,the migration laws of recirculated leachates are studied.The simulated results indicate that the various parameters (i.e.,settlement of MSW,pressure head,initial void ratio,etc.) have effects on the zone of impact,pressure head,water content of MSW and recirculation leachate volume per m of trench length.The design method of horizontal trenches is proposed for the bioreactor landfills.%水平沟回灌是生物反应器填埋场中渗滤液回灌的主要模式之一,为研究水平沟回灌时生物反应器填埋场中渗滤液的非饱和-饱和运移规律,垃圾体的饱和与非饱和区域采用不同水流控制方程,饱和区域的水流控制方程采用饱和Richards方程,对垃圾体非饱和区域,由质量守恒原理,以修正的Darcy定理为基础,结合Elagroudy等提出的垃圾体沉降模型,建立了考虑垃圾体沉降的非饱和渗滤液运移控制方程.基于建立的考虑沉降特性的二维非饱和-饱和水平沟回灌计算模型,研究了水平沟回灌时渗滤液在生物反应器填埋场中的运移规律,提出水平沟回灌系统的设计方法.

  9. Design of a biaxial mechanical loading bioreactor for tissue engineering.

    Science.gov (United States)

    Bilgen, Bahar; Chu, Danielle; Stefani, Robert; Aaron, Roy K

    2013-04-25

    We designed a loading device that is capable of applying uniaxial or biaxial mechanical strain to a tissue engineered biocomposites fabricated for transplantation. While the device primarily functions as a bioreactor that mimics the native mechanical strains, it is also outfitted with a load cell for providing force feedback or mechanical testing of the constructs. The device subjects engineered cartilage constructs to biaxial mechanical loading with great precision of loading dose (amplitude and frequency) and is compact enough to fit inside a standard tissue culture incubator. It loads samples directly in a tissue culture plate, and multiple plate sizes are compatible with the system. The device has been designed using components manufactured for precision-guided laser applications. Bi-axial loading is accomplished by two orthogonal stages. The stages have a 50 mm travel range and are driven independently by stepper motor actuators, controlled by a closed-loop stepper motor driver that features micro-stepping capabilities, enabling step sizes of less than 50 nm. A polysulfone loading platen is coupled to the bi-axial moving platform. Movements of the stages are controlled by Thor-labs Advanced Positioning Technology (APT) software. The stepper motor driver is used with the software to adjust load parameters of frequency and amplitude of both shear and compression independently and simultaneously. Positional feedback is provided by linear optical encoders that have a bidirectional repeatability of 0.1 μm and a resolution of 20 nm, translating to a positional accuracy of less than 3 μm over the full 50 mm of travel. These encoders provide the necessary position feedback to the drive electronics to ensure true nanopositioning capabilities. In order to provide the force feedback to detect contact and evaluate loading responses, a precision miniature load cell is positioned between the loading platen and the moving platform. The load cell has high accuracies of 0

  10. Design of a Biaxial Mechanical Loading Bioreactor for Tissue Engineering

    Science.gov (United States)

    Bilgen, Bahar; Chu, Danielle; Stefani, Robert; Aaron, Roy K.

    2013-01-01

    We designed a loading device that is capable of applying uniaxial or biaxial mechanical strain to a tissue engineered biocomposites fabricated for transplantation. While the device primarily functions as a bioreactor that mimics the native mechanical strains, it is also outfitted with a load cell for providing force feedback or mechanical testing of the constructs. The device subjects engineered cartilage constructs to biaxial mechanical loading with great precision of loading dose (amplitude and frequency) and is compact enough to fit inside a standard tissue culture incubator. It loads samples directly in a tissue culture plate, and multiple plate sizes are compatible with the system. The device has been designed using components manufactured for precision-guided laser applications. Bi-axial loading is accomplished by two orthogonal stages. The stages have a 50 mm travel range and are driven independently by stepper motor actuators, controlled by a closed-loop stepper motor driver that features micro-stepping capabilities, enabling step sizes of less than 50 nm. A polysulfone loading platen is coupled to the bi-axial moving platform. Movements of the stages are controlled by Thor-labs Advanced Positioning Technology (APT) software. The stepper motor driver is used with the software to adjust load parameters of frequency and amplitude of both shear and compression independently and simultaneously. Positional feedback is provided by linear optical encoders that have a bidirectional repeatability of 0.1 μm and a resolution of 20 nm, translating to a positional accuracy of less than 3 μm over the full 50 mm of travel. These encoders provide the necessary position feedback to the drive electronics to ensure true nanopositioning capabilities. In order to provide the force feedback to detect contact and evaluate loading responses, a precision miniature load cell is positioned between the loading platen and the moving platform. The load cell has high accuracies of 0

  11. Landfilling: Environmental Issues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Manfredi, Simone; Kjeldsen, Peter

    2011-01-01

    to air, soil and water caused by the processes stabilizing the waste in the landfill. The main factors controlling the actual environmental impacts from the landfilling are: the nature and amount of the waste landfilled, the geological and hydrological setting of the landfill, the landfill technology......, the extent and quality of the technical environmental protection measures introduced, the daily operation and the timescale. This chapter describes the main potential environmental impacts from landfills. The modern landfill is able to avoid most of these impacts. However, in the planning and design...... of landfills it is important to understand the potential environmental impacts, which must be avoided. The emissions of landfill gas and leachate causing most of the environmental risks are described in detail in the chapters addressing specific landfill types: Chapter 10.5 (mineral waste landfill), Chapter 10...

  12. Title I conceptual design for Pit 6 landfill closure at Lawrence Livermore National Laboratory Site 300

    Energy Technology Data Exchange (ETDEWEB)

    MacDonnell, B.A.; Obenauf, K.S. [Golder Associates, Inc., Alameda, CA (United States)

    1996-08-01

    The objective of this design project is to evaluate and prepare design and construction documents for a closure cover cap for the Pit 6 Landfill located at Lawrence Livermore National Laboratory Site 300. This submittal constitutes the Title I Design (Conceptual Design) for the closure cover of the Pit 6 Landfill. A Title I Design is generally 30 percent of the design effort. Title H Design takes the design to 100 percent complete. Comments and edits to this Title I Design will be addressed in the Title II design submittal. Contents of this report are as follows: project background; design issues and engineering approach; design drawings; calculation packages; construction specifications outline; and construction quality assurance plan outline.

  13. The effectiveness of a novel cartridge-based bioreactor design in supporting liver cells.

    Science.gov (United States)

    Niu, Mei; Hammond, Paul; Coger, Robin N

    2009-10-01

    There are a number of applications--ranging from temporary strategies for organ failure to pharmaceutical testing--that rely on effective bioreactor designs. The significance of these devices is that they provide an environment for maintaining cells in a way that allows them to perform key cellular and tissue functions. In the current study, a novel cartridge-based bioreactor was developed and evaluated. Its unique features include its capacity for cell support and the adaptable design of its cellular space. Specifically, it is able to accommodate functional and reasonably sized tissue (>2.0 x 10(8) cells), and can be easily modified to support a range of anchorage-dependent cells. To evaluate its efficacy, it was applied to liver support in the current study. This involved evaluating the performance of rat primary hepatocytes within the unique cartridges in culture--sans bioreactor--and after being loaded within the novel bioreactor. Compared to collagen sandwich culture functional controls, hepatocytes within the unique cartridge design demonstrated significantly higher albumin production and urea secretion rates when cultured under dynamic flow conditions--reaching peak values of 170 +/- 22 microg/10(6) cells/day and 195 +/- 18 microg/10(6) cells/day, respectively. The bioreactor's effectiveness in supporting live and functioning primary hepatocytes is also presented. Cell viability at the end of 15 days of culture in the new bioreactor was 84 +/- 18%, suggesting that the new design is effective in maintaining primary hepatocytes for at least 2 weeks in culture. Liver-specific functions of urea secretion, albumin synthesis, and cytochrome P450 activity were also assessed. The results indicate that hepatocytes are able to achieve good functional performance when cultured within the novel bioreactor. This is especially true in the case of cytochrome P450 activity, where by day 15 of culture, hepatocytes within the bioreactor reached values that were 56.6% higher

  14. Design considerations and challenges for mechanical stretch bioreactors in tissue engineering.

    Science.gov (United States)

    Lei, Ying; Ferdous, Zannatul

    2016-05-01

    With the increase in average life expectancy and growing aging population, lack of functional grafts for replacement surgeries has become a severe problem. Engineered tissues are a promising alternative to this problem because they can mimic the physiological function of the native tissues and be cultured on demand. Cyclic stretch is important for developing many engineered tissues such as hearts, heart valves, muscles, and bones. Thus a variety of stretch bioreactors and corresponding scaffolds have been designed and tested to study the underlying mechanism of tissue formation and to optimize the mechanical conditions applied to the engineered tissues. In this review, we look at various designs of stretch bioreactors and common scaffolds and offer insights for future improvements in tissue engineering applications. First, we summarize the requirements and common configuration of stretch bioreactors. Next, we present the features of different actuating and motion transforming systems and their applications. Since most bioreactors must measure detailed distributions of loads and deformations on engineered tissues, techniques with high accuracy, precision, and frequency have been developed. We also cover the key points in designing culture chambers, nutrition exchanging systems, and regimens used for specific tissues. Since scaffolds are essential for providing biophysical microenvironments for residing cells, we discuss materials and technologies used in fabricating scaffolds to mimic anisotropic native tissues, including decellularized tissues, hydrogels, biocompatible polymers, electrospinning, and 3D bioprinting techniques. Finally, we present the potential future directions for improving stretch bioreactors and scaffolds. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:543-553, 2016.

  15. Innovative landfill bioreactor systems for municipal solid waste treatment in East Africa aimed at optimal energy recovery and minimal greenhouse gas emissions

    NARCIS (Netherlands)

    Salukele, F.M.

    2013-01-01

    Landfilling is currently the dominant disposal method for municipal solid waste (MSW) in developing countries. Approximately 50% of the MSW generated in East Africa is disposed in landfills. Low costs and availability of land have made landfilling the most common waste management option in East Afri

  16. Innovative landfill bioreactor systems for municipal solid waste treatment in East Africa aimed at optimal energy recovery and minimal greenhouse gas emissions

    NARCIS (Netherlands)

    Salukele, F.M.

    2013-01-01

    Landfilling is currently the dominant disposal method for municipal solid waste (MSW) in developing countries. Approximately 50% of the MSW generated in East Africa is disposed in landfills. Low costs and availability of land have made landfilling the most common waste management option in East

  17. MOLECULAR AND CULTURAL METHODOLOGIES FOR ENUMERATING BACTERIA IN LANDFILL LEACHATES

    Science.gov (United States)

    Landfill bioreactor technology has been under investigation in the field for its potential economic and waste treatment benefits over conventional landfill systems. A better understanding of biological influences on the stabilization process is needed for incorporation into the e...

  18. Evaluation of Landfill Cover Design Options for Waste Disposal Sites in the Coastal Regions of Ghana

    Directory of Open Access Journals (Sweden)

    Kodwo Beedu Keelson

    2015-01-01

    Full Text Available Uncontrolled leachate generation from operational and closed waste disposal sites is a major environmental concern in the coastal regions of Ghana which have abundant surface water and groundwater resources. The Ghana Landfill Guidelines requires the provision of a final cover or capping system as part of a final closure plan for waste disposal sites in the country as a means of minimizing the harmful environmental effects of these emissions. However, this technical manual does not provide explicit guidance on the material types or configuration for landfill covers that would be suitable for the different climatic conditions in the country. Four landfill cover options which are based on the USEPA RCRA-type and evapotranspirative landfill cover design specifications were evaluated with the aid of the HELP computer program to determine their suitability for waste disposal sites located in the Western, Central and Greater Accra regions. The RCRA Subtitle C cover which yielded flux rates of less than 0.001 mm/yr was found to be suitable for the specific climatic conditions. The RCRA Subtitle D cover was determined to be unsuitable due to the production of very large flux rates in excess of 200 mm/yr. The results for the anisotropic barrier and capillary barrier covers were inconclusive. Recommendations for further study include a longer simulation period as well the study of the combined effects of different topsoil vegetative conditions and evaporative zone depths on the landfill water balance. The use of other water balance models such as EPIC, HYDRUS-2D and UNSAT-H for the evaluation of the evapotranspirative landfill cover design options should also be considered.

  19. DESIGNING SULFATE-REDUCING BACTERIA FIELD-BIOREACTORS USING THE BEST MODEL

    Science.gov (United States)

    DESIGNING SULFATE-REDUCING BACTERIA FIELD-BIOREACTORS USING THE BEST MODELMarek H. Zaluski1,3, Brian T. Park1, Diana R. Bless21 MSE Technology Applications; 200 Technology Way, Butte, Montana 59701, USA2 U.S. EPA, Office of Research and Development, Cincinna...

  20. Design concept for the solid waste landfill site:a case study of Chuzhou City,China

    Institute of Scientific and Technical Information of China (English)

    Wu Wentao

    2006-01-01

    This paper introduces landfill site of Chuzhou domestic waste, to which the improved anaerobic hygienic burying technology is applied. Chuzhou City, situated between Yangtze River and Huai River, is a window city in the east of Anhui Province. A landfill site with a capacity of 400 ton per day is to be constructed according to the city development plan and the garbage amount. This paper summarizes the landfill location, landform, groundwater; surface water,landfill stratal configuration, dominant wind, and the major machinery equipment. The projects of anti-percolation,seepage collection, seepage disposal, rainwater discharge, biogas diversion are deeply studied. The advanced design principle of the landfills is summarized, which is environment-friendly, science-oriented and economy-based. Environ ment-friendly principle is implemented in the selection of landfill location, construction of all projects, sealing up project and perfecting environment monitoring system; science-oriented principle prescribes that the design, construction, and management should be science-oriented; the selection of landfill location, design, plan optimization, resource-saving measures and comprehensive utilization should be economy-based. Chuzhou domestic waste landfill site is qualified as a golden model in this paper.

  1. Fluctuation of dissolved heavy metal concentrations in the leachate from anaerobic digestion of municipal solid waste in commercial scale landfill bioreactors: The effect of pH and associated mechanisms.

    Science.gov (United States)

    Xie, S; Ma, Y; Strong, P J; Clarke, W P

    2015-12-15

    Heavy metals present in landfill leachate have infrequently been related to complete anaerobic degradation municipal solid waste (MSW) due to discrete ages of deposited MSW layers and leachate channelling in landfills. In this study, anaerobic digestion of MSW was performed in two enclosed 1000 tonne bioreactors using a unique flood and drain process. Leachates were characterised in terms of pH, soluble chemical oxygen demand, volatile fatty acids (VFAs), ammonium nitrogen and heavy metals over the entire course of digestion. All parameters, including pH, fluctuated during acidogenesis, acetogenesis and methanogenesis, which strongly impacted on the dynamics of dissolved heavy metal concentrations. The simulation of dissolution and precipitation processes indicated that metal sulphide precipitation was not a factor as metal concentrations exceeded solubility limits. The correlation of pH and dissolved heavy metal concentrations indicated that other, mechanisms were involved in the homogenised conditions within the bioreactors. Beside dissolution and precipitation, the main processes most likely involved in metal distributions were adsorption (Zn, Cu, Ni, Pb and Cd), complexation (Cr) or combinations of both process (As and Co).

  2. Bioreactor principles

    Science.gov (United States)

    2001-01-01

    Cells cultured on Earth (left) typically settle quickly on the bottom of culture vessels due to gravity. In microgravity (right), cells remain suspended and aggregate to form three-dimensional tissue. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  3. Bioreactor principles

    Science.gov (United States)

    2001-01-01

    Cells cultured on Earth (left) typically settle quickly on the bottom of culture vessels due to gravity. In microgravity (right), cells remain suspended and aggregate to form three-dimensional tissue. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  4. Galvanotactic migration of EA.Hy926 endothelial cells in a novel designed electric field bioreactor.

    Science.gov (United States)

    Long, Haiyan; Yang, Gang; Wang, Zhengrong

    2011-12-01

    Endogenous direct current electric fields (dcEFs) play a significant role in major biological processes such as embryogenesis, wound healing, and tissue regeneration. In this study, the galvanotaxis of human umbilical vein endothelial cell line EA.Hy926 was investigated by using a novel designed bioreactor. The physical features of the bioreactor were discussed and analyzed by both numerical simulation method and equivalent circuit model method. EA.Hy926 cells were cultured in the bioreactor for 10-24 h under 50-250 mV/mm dcEFs. Cell migration direction, distance, and velocity were recorded under an online time-lapse microscope. The effects of serum and growth factor on cell galvanotatic migration were investigated. To further explore the role of dcEFs in regulating endothelial cells, we analyzed the endothelial cell proliferation and secretion of nitric oxide (NO), endothelin-1 (ET-1) in response to dcEFs of physiological strength. Our results showed that EA.Hy926 cells had an obvious directional migration to the cathode, and the EF-directed migration was voltage dependent. The results also showed dcEFs did not affect cell proliferation, but affected the productions of NO and ET-1. Our study also showed the novel bioreactor, with a compact and planar style, makes it more convenient and more reasonable for EF stimulation experiments than earlier chamber designs.

  5. 回灌频率对联合型生物反应器填埋场的影响研究%Effect of Recirculation Frequency in Anaerobic-semiaerobic Bioreactor Landfill

    Institute of Scientific and Technical Information of China (English)

    陈馨; 李启彬; 刘丹; 韩智勇

    2013-01-01

    为解决厌氧型生物反应器填埋场中氨氮积累问题,加速填埋场的稳定化进程,将厌氧生物反应器填埋场和准好氧矿化垃圾反应床串联.实验设置了1个厌氧型生物反应器填埋场(ANBL1#)作为参照组,2个厌氧-准好氧联合型生物反应器填埋场(AN-SABL2#、AN-SABL 3#)作为对照组,以研究不同回灌频率下AN-SABL的稳定化规律.研究结果表明:AN-SABL2#、AN-SABL3#可缩短酸化时间,渗滤液的pH值分别在94周、98周升至大于7,而ANBL1#渗滤液的pH值直至100周仍小于7.AN-SABL系统可有效降解渗滤液COD浓度,实验进行到100周左右时,AN-SABL2#、AN-SABL3#系统中厌氧柱D2、D3柱COD浓度仅为ANBL1#系统中厌氧柱D1柱的40.63%、12.5%,而准好氧柱对渗滤液COD的去除率大部分在95%以上.AN-SABL系统能缓解厌氧型生物反应器填埋场中氨氮积累问题,这主要依靠矿化垃圾床良好的生物脱氮作用,厌氧柱D1、D2、D3中NH3-N含量总体趋势为:NH3-ND1>NH3-Nm,NH3-ND1>NH3-ND2,准好氧d2、d3柱氨氮去除率均在90%以上,且厌氧-准好氧联合型生物反应器填埋场(AN-SABL)在实验产酸阶段低回灌频率(3d/次)对氨氮的去除有利,而后期高回灌频率(1 d/次)更有利.%Anaerobic bioreactor landfill with a semi-aerobic aged refuse bioreactor was studied for reducing high concentration ammonia nitrogen cumulated in anaerobic bioreactor landfill, in order to accelerate the stabilization of landfill ANBL1#, a simulated anaerobic bioreactor, as the reference group and two simulated anaerobic-semiaerobic bioreactors (AN-S ABL2#, AN-SABL3#) as control groups were devised, for studying the stabilization of AN -SABL operated at different leachate recirculation frequencies. Results indicated that leachate pH value in ANBL1# remained less than 7 until the 100th week. By contrast, the pH value of leachate in AN-SABL2# and AN-SABL3# both rose to more than 7 after 94 weeks and 98 weeks respectively

  6. Efficient high-throughput biological process characterization: Definitive screening design with the ambr250 bioreactor system.

    Science.gov (United States)

    Tai, Mitchell; Ly, Amanda; Leung, Inne; Nayar, Gautam

    2015-01-01

    The burgeoning pipeline for new biologic drugs has increased the need for high-throughput process characterization to efficiently use process development resources. Breakthroughs in highly automated and parallelized upstream process development have led to technologies such as the 250-mL automated mini bioreactor (ambr250™) system. Furthermore, developments in modern design of experiments (DoE) have promoted the use of definitive screening design (DSD) as an efficient method to combine factor screening and characterization. Here we utilize the 24-bioreactor ambr250™ system with 10-factor DSD to demonstrate a systematic experimental workflow to efficiently characterize an Escherichia coli (E. coli) fermentation process for recombinant protein production. The generated process model is further validated by laboratory-scale experiments and shows how the strategy is useful for quality by design (QbD) approaches to control strategies for late-stage characterization. © 2015 American Institute of Chemical Engineers.

  7. Navigating environmental, economic, and technological trade-offs in the design and operation of submerged anaerobic membrane bioreactors (AnMBRs).

    Science.gov (United States)

    Pretel, R; Shoener, B D; Ferrer, J; Guest, J S

    2015-12-15

    Anaerobic membrane bioreactors (AnMBRs) enable energy recovery from wastewater while simultaneously achieving high levels of treatment. The objective of this study was to elucidate how detailed design and operational decisions of submerged AnMBRs influence the technological, environmental, and economic sustainability of the system across its life cycle. Specific design and operational decisions evaluated included: solids retention time (SRT), mixed liquor suspended solids (MLSS) concentration, sludge recycling ratio (r), flux (J), and specific gas demand per membrane area (SGD). The possibility of methane recovery (both as biogas and as soluble methane in reactor effluent) and bioenergy production, nutrient recovery, and final destination of the sludge (land application, landfill, or incineration) were also evaluated. The implications of these design and operational decisions were characterized by leveraging a quantitative sustainable design (QSD) framework which integrated steady-state performance modeling across seasonal temperatures (using pilot-scale experimental data and the simulating software DESASS), life cycle cost (LCC) analysis, and life cycle assessment (LCA). Sensitivity and uncertainty analyses were used to characterize the relative importance of individual design decisions, and to navigate trade-offs across environmental, economic, and technological criteria. Based on this analysis, there are design and operational conditions under which submerged AnMBRs could be net energy positive and contribute to the pursuit of carbon negative wastewater treatment.

  8. Navigating environmental, economic, and technological trade-offs in the design and operation of submerged anaerobic membrane bioreactors (AnMBRs)

    KAUST Repository

    Pretel, R.

    2015-12-01

    © 2015 Elsevier Ltd. Anaerobic membrane bioreactors (AnMBRs) enable energy recovery from wastewater while simultaneously achieving high levels of treatment. The objective of this study was to elucidate how detailed design and operational decisions of submerged AnMBRs influence the technological, environmental, and economic sustainability of the system across its life cycle. Specific design and operational decisions evaluated included: solids retention time (SRT), mixed liquor suspended solids (MLSS) concentration, sludge recycling ratio (r), flux (J), and specific gas demand per membrane area (SGD). The possibility of methane recovery (both as biogas and as soluble methane in reactor effluent) and bioenergy production, nutrient recovery, and final destination of the sludge (land application, landfill, or incineration) were also evaluated. The implications of these design and operational decisions were characterized by leveraging a quantitative sustainable design (QSD) framework which integrated steady-state performance modeling across seasonal temperatures (using pilot-scale experimental data and the simulating software DESASS), life cycle cost (LCC) analysis, and life cycle assessment (LCA). Sensitivity and uncertainty analyses were used to characterize the relative importance of individual design decisions, and to navigate trade-offs across environmental, economic, and technological criteria. Based on this analysis, there are design and operational conditions under which submerged AnMBRs could be net energy positive and contribute to the pursuit of carbon negative wastewater treatment.

  9. Long term organ culture of human prostate tissue in a NASA-designed rotating wall bioreactor

    Science.gov (United States)

    Margolis, L.; Hatfill, S.; Chuaqui, R.; Vocke, C.; Emmert-Buck, M.; Linehan, W. M.; Duray, P. H.

    1999-01-01

    PURPOSE: To maintain ex vivo integral prostatic tissue including intact stromal and ductal elements using the NASA-designed Rotating Wall Vessel (RWV) which maintains colocalized cells in an environment that promotes both three-dimensional cellular interactions together with the uniform mass transfer of nutrients and metabolic wastes. MATERIALS AND METHODS: Samples of normal prostate were obtained as a byproduct of transurethral prostatectomy or needle biopsy. Prostatic tissue dissected into small 1 x 1 mm. blocks was cultured in the Rotating Wall Vessel (RWV) Bioreactor for various time periods and analyzed using histological, immunochemical, and total cell RNA assays. RESULTS: We report the long term maintenance of benign explanted human prostate tissue grown in simple culture medium, under the simulated microgravity conditions afforded by the RWV bioreactor. Mesenchymal stromal elements including blood vessels and architecturally preserved tubuloglandular acini were maintained for a minimum of 28 days. Cytokeratins, vimentin and TGF-beta2 receptor and ligand were preserved through the entire culture period as revealed by immunocytochemistry. Prostatic acid phosphatase (PAP) was continuously expressed during the culture period, although somewhat decreased. Prostatic specific antigen (PSA) and its transcript were down regulated over time of culture. Prostatic carcinoma cells from the TSU cell line were able to invade RWV-cultured benign prostate tissue explants. CONCLUSIONS: The RWV bioreactor represents an additional new technology for culturing prostate tissue for further investigations concerning the basic physiology and pathobiology of this clinically important tissue.

  10. Design and evaluation of a bioreactor with application to forensic burial environments.

    Science.gov (United States)

    Dunphy, Melissa A; Weisensee, Katherine E; Mikhailova, Elena A; Harman, Melinda K

    2015-12-01

    Existing forensic taphonomic methods lack specificity in estimating the postmortem interval (PMI) in the period following active decomposition. New methods, such as the use of citrate concentration in bone, are currently being considered; however, determining the applicability of these methods in differing environmental contexts is challenging. This research aims to design a forensic bioreactor that can account for environmental factors known to impact decomposition, specifically temperature, moisture, physical damage from animals, burial depth, soil pH, and organic matter content. These forensically relevant environmental variables were characterized in a soil science context. The resulting metrics were soil temperature regime, soil moisture regime, slope, texture, soil horizon, cation exchange capacity, soil pH, and organic matter content. Bioreactor chambers were constructed using sterilized thin-walled polystyrene boxes housed in calibrated temperature units. Gravesoil was represented using mineral soil (Ultisols), and organic soil proxy for Histosols, horticulture mix. Gravesoil depth was determined using mineral soil horizons A and Bt2 to simulate surface scatter and shallow grave burial respectively. A total of fourteen different environmental conditions were created and controlled successfully over a 90-day experiment. These results demonstrate successful implementation and control of forensic bioreactor simulating precise environments in a single research location, rather than site-specific testing occurring in different geographic regions. Bone sections were grossly assessed for weathering characteristics, which revealed notable differences related to exposure to different temperature regimes and soil types. Over the short 90-day duration of this experiment, changes in weathering characteristics were more evident across the different temperature regimes rather than the soil types. Using this methodology, bioreactor systems can be created to replicate many

  11. NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    Bioreactor Demonstration System (BDS) comprises an electronics module, a gas supply module, and the incubator module housing the rotating wall vessel and its support systems. Nutrient media are pumped through an oxygenator and the culture vessel. The shell rotates at 0.5 rpm while the irner filter typically rotates at 11.5 rpm to produce a gentle flow that ensures removal of waste products as fresh media are infused. Periodically, some spent media are pumped into a waste bag and replaced by fresh media. When the waste bag is filled, an astronaut drains the waste bag and refills the supply bag through ports on the face of the incubator. Pinch valves and a perfusion pump ensure that no media are exposed to moving parts. An Experiment Control Computer controls the Bioreactor, records conditions, and alerts the crew when problems occur. The crew operates the system through a laptop computer displaying graphics designed for easy crew training and operation. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. See No. 0101825 for a version with major elements labeled, and No. 0103180 for an operational schematic. 0101816

  12. NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    Bioreactor Demonstration System (BDS) comprises an electronics module, a gas supply module, and the incubator module housing the rotating wall vessel and its support systems. Nutrient media are pumped through an oxygenator and the culture vessel. The shell rotates at 0.5 rpm while the irner filter typically rotates at 11.5 rpm to produce a gentle flow that ensures removal of waste products as fresh media are infused. Periodically, some spent media are pumped into a waste bag and replaced by fresh media. When the waste bag is filled, an astronaut drains the waste bag and refills the supply bag through ports on the face of the incubator. Pinch valves and a perfusion pump ensure that no media are exposed to moving parts. An Experiment Control Computer controls the Bioreactor, records conditions, and alerts the crew when problems occur. The crew operates the system through a laptop computer displaying graphics designed for easy crew training and operation. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. See No. 0101825 for a version with major elements labeled, and No. 0103180 for an operational schematic. 0101816

  13. NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    Biotechnology Specimen Temperature Controller (BSTC) will cultivate cells until their turn in the bioreactor; it can also be used in culturing experiments that do not require the bioreactor. The BSTC comprises four incubation/refrigeration chambers individually set at 4 to 50 deg. C (near-freezing to above body temperature). Each chamber holds three rugged tissue chamber modules (12 total), clear Teflon bags holding 30 ml of growth media, all positioned by a metal frame. Every 7 to 21 days (depending on growth rates), an astronaut uses a shrouded syringe and the bags' needleless injection ports to transfer a few cells to a fresh media bag, and to introduce a fixative so that the cells may be studied after flight. The design also lets the crew sample the media to measure glucose, gas, and pH levels, and to inspect cells with a microscope. The controller is monitored by the flight crew through a 23-cm (9-inch) color computer display on the face of the BSTC. This view shows the BTSC with the front panel open. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  14. Landfilling: Concepts and Challenges

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Scharff, H.; Hjelmar, O.

    2011-01-01

    Landfilling of waste historically has been the main management route for waste, and in many parts of the world it still is. Landfills have developed from open polluting dumps to modern highly engineered facilities with sophisticated control measures and monitoring routines. However, in spite of all...... new approaches and technological advancement the landfill still is a long lasting accumulation of waste in the environment. Much of current landfill design and technology has been introduced as a reaction to problems encountered at actual landfills. The solution was in many cases sought in isolation...... to understand the concepts, the processes and the long-term aspects of landfilling. This chapter describes the main conceptual aspects of landfilling. The historical development is presented and key issues of time frames, mass balances and technical approaches are discussed. The environmental issues...

  15. A COMPARISON OF MOLECULAR AND CULTURAL METHODOLOGIES FOR ENUMERATING BACTERIA IN LANDFILL LEACHATES

    Science.gov (United States)

    Landfill bioreactor technology has been under investigation in the field for its potential economic and waste treatment benefits over conventional landfill systems. A better understanding of biological influences on the stabilization process is needed for incorporation into the e...

  16. Design of electrical stimulation bioreactors for cardiac tissue engineering.

    Science.gov (United States)

    Tandon, N; Marsano, A; Cannizzaro, C; Voldman, J; Vunjak-Novakovic, G

    2008-01-01

    Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. Carbon electrodes were found in past studies to have the best current injection characteristics. The goal of this study was to develop rational experimental design principles for the electrodes and stimulation regime, in particular electrode configuration, electrode ageing, and stimulation amplitude. Carbon rod electrodes were compared via electrochemical impedance spectroscopy (EIS) and we identified a safety range of 0 to 8 V/cm by comparing excitation thresholds and maximum capture rates for neonatal rat cardiomyocytes cultured with electrical stimulation. We conclude with recommendations for studies involving carbon electrodes for cardiac tissue engineering.

  17. A Novel Designed Bioreactor for Recovering Precious Metals from Waste Printed Circuit Boards.

    Science.gov (United States)

    Jujun, Ruan; Jie, Zheng; Jian, Hu; Zhang, Jianwen

    2015-08-28

    For recovering precious metals from waste printed circuit boards (PCBs), a novel hybrid technology including physical and biological methods was developed. It consisted of crushing, corona-electrostatic separation, and bioleaching. Bioleaching process is the focus of this paper. A novel bioreactor for bioleaching was designed. Bioleaching was carried out using Pseudomonas chlororaphis. Bioleaching experiments using mixed particles of Au and Cu were performed and leachate contained 0.006 mg/L, 2823 mg/L Au(+) and Cu(2+) respectively. It showed when Cu existed, the concentrations of Au were extremely small. This provided the feasibility to separate Cu from Au. The method of orthogonal experimental design was employed in the simulation bioleaching experiments. Experimental results showed the optimized parameters for separating Cu from Au particles were pH 7.0, temperature 22.5 °C, and rotation speed 80 r/min. Based on the optimized parameters obtained, the bioreactor was operated for recovering mixed Au and Cu particles. 88.1 wt.% of Cu and 76.6 wt.% of Au were recovered. The paper contributed important information to recover precious metals from waste PCBs.

  18. A Novel Designed Bioreactor for Recovering Precious Metals from Waste Printed Circuit Boards

    Science.gov (United States)

    Jujun, Ruan; Jie, Zheng; Jian, Hu; Zhang, Jianwen

    2015-01-01

    For recovering precious metals from waste printed circuit boards (PCBs), a novel hybrid technology including physical and biological methods was developed. It consisted of crushing, corona-electrostatic separation, and bioleaching. Bioleaching process is the focus of this paper. A novel bioreactor for bioleaching was designed. Bioleaching was carried out using Pseudomonas chlororaphis. Bioleaching experiments using mixed particles of Au and Cu were performed and leachate contained 0.006 mg/L, 2823 mg/L Au+ and Cu2+ respectively. It showed when Cu existed, the concentrations of Au were extremely small. This provided the feasibility to separate Cu from Au. The method of orthogonal experimental design was employed in the simulation bioleaching experiments. Experimental results showed the optimized parameters for separating Cu from Au particles were pH 7.0, temperature 22.5 °C, and rotation speed 80 r/min. Based on the optimized parameters obtained, the bioreactor was operated for recovering mixed Au and Cu particles. 88.1 wt.% of Cu and 76.6 wt.% of Au were recovered. The paper contributed important information to recover precious metals from waste PCBs. PMID:26316021

  19. 简析生活垃圾卫生填埋场封场设计%Closure Design of Domestic Waste Sanitary Landfill Sites

    Institute of Scientific and Technical Information of China (English)

    吴健萍

    2011-01-01

    Functions of closure of domestic waste sanitary landfill sites were sketched. Main contents about closure design were analyzed, including landfill pile shaping, structure determining of closure cover system, collection and drainage of landfill gas, and collection and discharge of rainwater in landfill pile.%简述了生活垃圾卫生填埋场封场的作用,分析了封场设计中堆体整形、封场覆盖系统结构的确定、填埋气体的收集导排、垃圾堆体雨水的收集排放等主要内容.

  20. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    the landfill section has been filled or several years later depending on the settlement patterns. Significant differential settlements may disturb the functioning of the top cover. The specific design of the cover system depends on the type of waste landfilled (municipal, hazardous, or inert waste...... such as lowpermeability clay soils and geomembranes are required. The avoidance of water input to organic waste may impede the microbial stabilization processes including gas generation. Therefore watertight top covers may be in conflict with the purposes of reactor landfills (see Chapter 10.6). At some sites covers...... sometimes are made to include components for recirculation of landfill leachate (see Section 10.9.2 for more details). The top cover is an important factor in the water management of landfills. Details about water infiltration through top covers and its influence on the hydrology of the landfill is covered...

  1. Landfill Top Covers

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Kjeldsen, Peter

    2011-01-01

    is landscaped in order to fit into the surrounding area/environment or meet specific plans for the final use of the landfill. To fulfill the above listed requirements landfill covers are often multicomponent systems which are placed directly on top of the waste. The top cover may be placed immediately after...... the landfill section has been filled or several years later depending on the settlement patterns. Significant differential settlements may disturb the functioning of the top cover. The specific design of the cover system depends on the type of waste landfilled (municipal, hazardous, or inert waste...... however, top covers may be the only environmental protection measure. In some landfill regulations (for instance the Subtitle D landfills receiving municipal solid waste in the USA) it is required to minimize infiltration into the waste layers. Therefore top covers containing liner components...

  2. Design and Validation of a Cyclic Strain Bioreactor to Condition Spatially-Selective Scaffolds in Dual Strain Regimes

    Directory of Open Access Journals (Sweden)

    J. Matthew Goodhart

    2014-03-01

    Full Text Available The objective of this study was to design and validate a unique bioreactor design for applying spatially selective, linear, cyclic strain to degradable and non-degradable polymeric fabric scaffolds. This system uses a novel three-clamp design to apply cyclic strain via a computer controlled linear actuator to a specified zone of a scaffold while isolating the remainder of the scaffold from strain. Image analysis of polyethylene terephthalate (PET woven scaffolds subjected to a 3% mechanical stretch demonstrated that the stretched portion of the scaffold experienced 2.97% ± 0.13% strain (mean ± standard deviation while the unstretched portion experienced 0.02% ± 0.18% strain. NIH-3T3 fibroblast cells were cultured on the PET scaffolds and half of each scaffold was stretched 5% at 0.5 Hz for one hour per day for 14 days in the bioreactor. Cells were checked for viability and proliferation at the end of the 14 day period and levels of glycosaminoglycan (GAG and collagen (hydroxyproline were measured as indicators of extracellular matrix production. Scaffolds in the bioreactor showed a seven-fold increase in cell number over scaffolds cultured statically in tissue culture plastic petri dishes (control. Bioreactor scaffolds showed a lower concentration of GAG deposition per cell as compared to the control scaffolds largely due to the great increase in cell number. A 75% increase in hydroxyproline concentration per cell was seen in the bioreactor stretched scaffolds as compared to the control scaffolds. Surprisingly, little differences were experienced between the stretched and unstretched portions of the scaffolds for this study. This was largely attributed to the conditioned and shared media effect. Results indicate that the bioreactor system is capable of applying spatially-selective, linear, cyclic strain to cells growing on polymeric fabric scaffolds and evaluating the cellular and matrix responses to the applied strains.

  3. Towards a Tissue-Engineered Ligament: Design and Preliminary Evaluation of a Dedicated Multi-Chamber Tension-Torsion Bioreactor

    Directory of Open Access Journals (Sweden)

    Cédric P. Laurent

    2014-02-01

    Full Text Available Tissue engineering may constitute a promising alternative to current strategies in ligament repair, providing that suitable scaffolds and culture conditions are proposed. The objective of the present contribution is to present the design and instrumentation of a novel multi-chamber tension-torsion bioreactor dedicated to ligament tissue engineering. A preliminary biological evaluation of a new braided scaffold within this bioreactor under dynamic loading is reported, starting with the development of a dedicated seeding protocol validated from static cultures. The results of these preliminary biological characterizations confirm that the present combination of scaffold, seeding protocol and bioreactor may enable us to head towards a suitable ligament tissue-engineered construct.

  4. Inverse Estimation of Temperature Profiles in Landfills Using Heat Recovery Fluids Measurements

    Directory of Open Access Journals (Sweden)

    C. Solisio

    2012-01-01

    Full Text Available In addition to leachate and gas emission analysis, temperature variations in municipal solid waste landfills are routinely monitored for safety and health reasons, such as the increased production of biogas or the danger of spontaneous combustion phenomena if the temperature exceeds 70–75°C. The increasing constraints on greenhouse gas emissions and the convenience of fuel and heat recovery have helped develop a global approach to landfills' operation and maintenance, generally referred to as bioreactor landfill management. The heat recovery piping we are presently designing can be a significant part of this approach. The heat gained by a fluid circulated in a closed network through the landfill is transferred to an external heat exchanger or used directly as warm water. Additionally, it can help reduce landfill temperature levels and control biogas generation. Since the pipes diameter is large enough to allow for a radial temperature gradient, this information can be used for an inverse estimation of the temperature profile in the landfill which constitutes the boundary conditions of the resulting heat transfer problem. In this paper, we describe an algorithm for regularising the resulting ill-posed free boundary estimation problem using sampled data of the heat recovery fluid on exiting the landfill.

  5. Methylated mercury species in municipal waste landfill gas sampled in Florida, USA

    Science.gov (United States)

    Lindberg, S. E.; Wallschläger, D.; Prestbo, E. M.; Bloom, N. S.; Price, J.; Reinhart, D.

    Mercury-bearing material has been placed in municipal landfills from a wide array of sources including fluorescent lights, batteries, electrical switches, thermometers, and general waste. Despite its known volatility, persistence, and toxicity in the environment, the fate of mercury in landfills has not been widely studied. The nature of landfills designed to reduce waste through generation of methane by anaerobic bacteria suggests the possibility that these systems might also serve as bioreactors for the production of methylated mercury compounds. The toxicity of such species mandates the need to determine if they are emitted in municipal landfill gas (LFG). In a previous study, we had measured levels of total gaseous mercury (TGM) in LFG in the μg/m 3 range in two Florida landfills, and elevated levels of monomethyl mercury (MMM) were identified in LFG condensate, suggesting the possible existence of gaseous organic Hg compounds in LFG. In the current study, we measured TGM, Hg 0, and methylated mercury compounds directly in LFG from another Florida landfill. Again, TGM was in the μg/m 3 range, MMM was found in condensate, and this time we positively identified dimethyl mercury (DMM) in the LGF in the ng/m 3 range. These results identify landfills as a possible anthropogenic source of DMM emissions to air, and may help explain the reports of MMM in continental rainfall.

  6. Bioreactor design considerations in the production of high-quality microbial exopolysaccaride

    Energy Technology Data Exchange (ETDEWEB)

    Lawford, H.G.; Rousseau, J.D. [Univ. of Toronto, Ontario (Canada)

    1991-12-31

    An examination into the effect of bioreactor design on the production of {beta},1,3-glucan exopolysaccharide ({open_quotes}curdlan{close_quotes}) by selected patent cultures of Alcaligenes faecalis and Agrobacterium radiobacter revealed that low shear mixing achieved through the replacement of the radial-flow flat-blade impellers that are commonly supplied in {open_quotes}standard{close_quotes} commercial bioreactors, by low shear (high-pumping) axial-flow impellers, leads to an increase in the quality of the exopolymer recovered during the stationary-phase of batch fermentations. Whereas {open_quotes}Rushton turbine{close_quotes} impellers were effective in providing high rates of oxygen transfer necessary for high cell density fermentations, the high shear-to-flow ratio characteristic of this design produced a product of inferior quality, but with characteristics very similar to that of the commercially available {open_quotes}curdlan standard.{close_quotes} Curdlan is water insoluble, and consequently, the fermentation broth is of a relative low viscosity compared to other soluble microbial polysaccharides. Whereas curdlan does not constrain mass transfer from gas to liquid, it nevertheless offers a resistance to oxygen transfer from the liquid to the cell by virtue of the layer of insoluble exopolymer surrounding the cell mass thereby necessitating an unexpectedly high dissolved oxygen concentration for maximal productivity. The requirement for high volumetric oxygen transfer can be met by low shear designs with axial-flow impellers, providing gas dispersion is assisted by the use of sparging devices consisting of microporous materials.

  7. Toxicological characterization of a novel wastewater treatment process using EDTA-Na2Zn as draw solution (DS) for the efficient treatment of MBR-treated landfill leachate.

    Science.gov (United States)

    Niu, Aping; Ren, Yi-Wei; Yang, Li; Xie, Shao-Lin; Jia, Pan-Pan; Zhang, Jing-Hui; Wang, Xiao; Li, Jing; Pei, De-Sheng

    2016-07-01

    Landfill leachate has become an important source of environmental pollution in past decades, due to the increase of waste volume. Acute toxic and genotoxic hazards to organisms can be caused by landfill leachate. Thus, how to efficiently recover water from landfill leachate and effectively eliminate combined toxicity of landfill leachate are the most pressing issues in waste management. In this study, EDTA-Na2Zn as draw solution (DS) was used to remove the toxicity of membrane bioreactor-treated landfill leachate (MBR-treated landfill leachate) in forward osmosis (FO) process, and nanofiltration (NF) was designed for recovering the diluted DS. Zebrafish and human cells were used for toxicity assay after the novel wastewater treatment process using EDTA-Na2Zn as DS. Results showed that the water recovery rate of MBR-treated landfill leachate (M-LL) in FO membrane system could achieve 66.5% and 71.2% in the PRO and FO mode respectively, and the diluted DS could be efficiently recovered by NF. Toxicity tests performed by using zebrafish and human cells showed that M-LL treated by EDTA-Na2Zn had no toxicity effect on zebrafish larvae and human cells, but it had very slight effect on zebrafish embryos. In conclusion, all results indicated that EDTA-Na2Zn as DS can effectively eliminate toxicity of landfill leachate and this method is economical and eco-friendly for treatment of different types of landfill leachate.

  8. Engineering parameters in bioreactor's design: a critical aspect in tissue engineering

    NARCIS (Netherlands)

    dds., N.; Amoabediny, G.; Pouran, B.; Tabesh, H.; Shokrgozar, M.A.; Haghighipour, N.; Khatibi, N.; Anisi, F.; Mottaghy, K.; Zandieh-Doulabi, B.

    2013-01-01

    Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transf

  9. A Water Balance Study of Four Landfill Cover Designs at Material Disposal Area B in Los Alamos, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    David D. Breshears; Fairley J. Barnes; John W. Nyhan; Johnny A. Salazar

    1998-09-01

    The goal of disposing of low-level radioactive and hazardous waste in shallow landfills is to reduce risk to human health and the environment by isolating contaminants until they no longer pose an unacceptable hazard. In order to achieve this, the Department of Energy Environmental Restoration Program is comparing the performance of several different surface covers at Material Disposal Area (MDA) B in Los Alamos. Two conventional landfill were compared with an improved cover designed to minimize plant and animal intrusion and to minimize water infiltration into the underlying wastes. The conventional covers varied in depth and both conventional and improved designs had different combinations of vegetation (grass verses shrub) and gravel mulch (no mulch verses mulch). These treatments were applied to each of 12 plots and water balance parameters were measured from March1987 through June 1995. Adding a gravel mulch significantly influenced the plant covered field plots receiving no gravel mulch averaged 21.2% shrub cover, while plots with gravel had a 20% larger percent cover of shrubs. However, the influence of gravel mulch on the grass cover was even larger than the influence on shrub cover, average grass cover on the plots with no gravel was 16.3%, compared with a 42% increase in grass cover due to gravel mulch. These cover relationships are important to reduce runoff on the landfill cover, as shown by a regression model that predicts that as ground cover is increased from 30 to 90%,annual runoff is reduced from 8.8 to 0.98 cm-a nine-fold increase. We also found that decreasing the slope of the landfill cover from 6 to 2% reduced runoff from the landfill cover by 2.7-fold. To minimize the risk of hazardous waste from landfills to humans, runoff and seepage need to be minimized and evapotranspiration maximized on the landfill cover. This has to be accomplished for dry and wet years at MDA B. Seepage consisted of 1.9% and 6.2% of the precipitation in the average and

  10. 联合型生物反应器填埋场厌氧单元产甲烷规律研究%Study on Methane Generation Regulation in Anaerobic-semiaerobic Bioreactor Anaerobic Landfill

    Institute of Scientific and Technical Information of China (English)

    宋豪娟; 刘丹; 韩智勇; 王宁

    2013-01-01

    基于模拟实验,研究新型厌氧型生物反应器(ANBL)-准好氧矿化垃圾联合型生物反应器(SAABR)厌氧单元产气速率、产气CH4含量以及累计产CH4量的变化规律.实验证明,由于回灌复氧后的渗滤液甲烷菌的活性受到抑制,AN-SABL中的厌氧填埋单元的产气受到了抑制,但较高的回灌频率使得渗滤液与微生物的接触机会增多,利于垃圾产气;综合分析产气CH4含量、渗滤液COD和渗滤液pH值,在此判断3个ANBL CH4发酵阶段分别为705~820,690~ 800和660~740 d,该阶段产气φ(CH4)最大值分别为78.6%,74.1%和71.5%.建立了ANBL累计产CH4量的指数增长模型,对生物反应器CH.的收集和利用有重要意义.%Alstract:Based on the experimental simulation device,the regulation of the gas production,content of methane and cumulative methane production in the anaerobic-semiaerobic bioreactor landfill were studied.It was proved that,methane germ of the activity was repressed because of leachate recirculation to infuse to reply oxygen,and gas production in the ANSABL was repressed,but higher leachate recirculation frequency improved the contact opportunity of leachate and microorganism,then benefit gas production; comprehensively analyzed the gas methane content,leachate COD and leachate pH,this research judged three ANBL methane ferments stage were 705 ~ 820 d,690 ~ 800 d and 660 ~ 740 d,that stage the biggest content of methane is 78.6%,74.1% and 71.5%.The index number growth model of the ANBL cumulative methane was built up,which was important to collections and exploitation of bioreactor methane.

  11. Considerations on the design and financial feasibility of full-scale membrane bioreactors for municipal applications.

    Science.gov (United States)

    Brepols, Ch; Schäfer, H; Engelhardt, N

    2010-01-01

    Based on the practical experience in design and operation of three full-scale membrane bioreactors (MBR) for municipal wastewater treatment that were commissioned since 1999, an overview on the different design concepts that were applied to the three MBR plants is given. The investment costs and the energy consumption of the MBRs and conventional activated sludge (CAS) plants (with and without tertiary treatment) in the Erft river region are compared. It is found that the specific investment costs of the MBR plants are lower than those of comparable CAS with tertiary treatment. A comparison of the specific energy demand of MBRs and conventional WWTPs is given. The structure of the MBRs actual operational costs is analysed. It can be seen that energy consumption is only responsible for one quarter to one third of all operational expenses. Based on a rough design and empirical cost data, a cost comparison of a full-scale MBR and a CAS is carried out. In this example the CAS employs a sand filtration and a disinfection in order to achieve comparable effluent quality. The influence of membrane lifetime on life cycle cost is assessed.

  12. Cryogenic Heat-Exchanger Design for Freeze-out Removal of Carbon Dioxide from Landfill Gas

    Science.gov (United States)

    Chang, Ho-Myung; Chung, Myung Jin; Park, Seong Bum

    A cryogenic heat exchanger to remove carbon dioxide from landfill gas (LFG) is proposed and designed for applications to LNG production in distributed-scale. Since the major components of LFG are methane and carbon dioxide, CO2 removal is a significant pre-process in the liquefaction systems. A new and simple approach is proposed to directly remove carbon dioxide as frost on the surface wall along the cooling passage in a liquefying heat exchanger and to install two identical heat exchangers in parallel for alternative switching. As a first step of feasibility study, combined heat and mass transfer analysis is performed on the freeze-out process of CO2 in a counterflow heat exchanger, where CH4-CO2 mixture is cooled below its frost temperature in thermal contact with cold refrigerant. Engineering correlations for the analogy of heat and mass transfer are incorporated into numerical heat exchanger analysis with detailed fluid properties. The developed analytical model is used to estimate the distribution of CO2 accumulation and the required heat exchanger size with latent thermal load for the cryogenic CO2 removal in various operating conditions.

  13. NASA Bioreactor Demonstration System

    Science.gov (United States)

    2002-01-01

    Leland W. K. Chung (left), Director, Molecular Urology Therapeutics Program at the Winship Cancer Institute at Emory University, is principal investigator for the NASA bioreactor demonstration system (BDS-05). With him is Dr. Jun Shu, an assistant professor of Orthopedics Surgery from Kuming Medical University China. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: Emory University.

  14. Bioreactor process parameter screening utilizing a Plackett-Burman design for a model monoclonal antibody.

    Science.gov (United States)

    Agarabi, Cyrus D; Schiel, John E; Lute, Scott C; Chavez, Brittany K; Boyne, Michael T; Brorson, Kurt A; Khan, Mansoor A; Read, Erik K

    2015-06-01

    Consistent high-quality antibody yield is a key goal for cell culture bioprocessing. This endpoint is typically achieved in commercial settings through product and process engineering of bioreactor parameters during development. When the process is complex and not optimized, small changes in composition and control may yield a finished product of less desirable quality. Therefore, changes proposed to currently validated processes usually require justification and are reported to the US FDA for approval. Recently, design-of-experiments-based approaches have been explored to rapidly and efficiently achieve this goal of optimized yield with a better understanding of product and process variables that affect a product's critical quality attributes. Here, we present a laboratory-scale model culture where we apply a Plackett-Burman screening design to parallel cultures to study the main effects of 11 process variables. This exercise allowed us to determine the relative importance of these variables and identify the most important factors to be further optimized in order to control both desirable and undesirable glycan profiles. We found engineering changes relating to culture temperature and nonessential amino acid supplementation significantly impacted glycan profiles associated with fucosylation, β-galactosylation, and sialylation. All of these are important for monoclonal antibody product quality.

  15. Numerical investigation of a bubble-column photo-bioreactor design for biodiesel production from microalgae

    Energy Technology Data Exchange (ETDEWEB)

    Seo, I.H.; Lee, I.B.; Hwang, H.S.; Hong, S.W.; Bitog, J.P.; Kwon, K.S.; Choi, J.S.; Song, S.H. [Seoul National Univ., Seoul (Korea, Democratic People' s Republic of). Dept. of Rural Systems Engineering and Research Inst. for Agriculture and Life Sciences

    2010-07-01

    Biodiesel made from vegetable oil is among the most desirable of renewable energy sources because it can be a substitute for diesel oil. However, biodiesel from soybean or corn can be confronted with a food crisis. Microalgae is a new biodiesel source which contains high oil lipids with a high growth rate, and which also offers value-added products from the residue, such as cosmetics, health functional food or pharmaceuticals. Microalgae are best cultivated in photo-bioreactors (PBRs) where light, nutrients, carbon dioxide and temperature can be controlled. Despite the current availability of PBRs, only a few can be practically used for mass production. Computational fluid dynamics (CFD) was used in this study to design an optimum bubble-column PBR for mass production of microalgae. Multi-phase models including bubble movement, meshes and time step independent tests were considered to develop the 3-dimensional CFD model. Particle Image Velocimetry (PIV) tests were used to enhance and validate the model. Different types of PBRs were simulated and compared quantitatively with the microalgae's growth model.

  16. Hydrodynamic extensional stress during the bubble bursting process for bioreactor system design

    Science.gov (United States)

    Tran, Thanh Tinh; Lee, Eun Gyo; Lee, In Su; Woo, Nam Sub; Han, Sang Mok; Kim, Young Ju; Hwang, Wook Ryol

    2016-11-01

    Cell damage, one of critical issues in the bioreactor design for animal cell culture, is caused mainly from the bubble bursting at the free surface subjected to strong extensional flows. In this work, extensive computational studies are performed to investigate bubble bursting process in great details. Extensive numerical simulations are performed for a wide range of bubble diameters (from 0.5 to 6 mm) and the surface tension values (from 0.03 to 0.072 N/m), with which effects of the bubble size and surfactant (PF68) concentration on the hydrodynamic stress are investigated. For all the cases, the maximum extensional stress appears at the instance when receding films impact each other at the bottom of the bubble. A model equation based on numerical simulations is presented to predict the maximum extensional stress as a function of the bubble diameter and the surface tension. The bubble diameter has turned out to contribute significantly the maximum hydrodynamic extensional stress. In addition, the bubble collapsed time and the affected volume around a bubble subjected to the critical extensional stress are investigated. The extensional stress estimation is reported as a function of the bubble size and the surface tension. The influence of the bubble size on the maximum stress dominates and extensional stress reaches up to the order of 104 Pa for bubble size of 0.5 mm.

  17. A multiobjective decision support/numerical modeling approach for design and evaluation of shallow landfill burial systems

    Energy Technology Data Exchange (ETDEWEB)

    Ascough, II, James Clifford [Purdue Univ., Lafayette, IN (United States)

    1992-05-01

    The capability to objectively evaluate design performance of shallow landfill burial (SLB) systems is of great interest to diverse scientific disciplines, including hydrologists, engineers, environmental scientists, and SLB regulators. The goal of this work was to develop and validate a procedure for the nonsubjective evaluation of SLB designs under actual or simulated environmental conditions. A multiobjective decision module (MDM) based on scoring functions (Wymore, 1988) was implemented to evaluate SLB design performance. Input values to the MDM are provided by hydrologic models. The MDM assigns a total score to each SLB design alternative, thereby allowing for rapid and repeatable design performance evaluation. The MDM was validated for a wide range of SLB designs under different climatic conditions. Rigorous assessment of SLB performance also requires incorporation of hydrologic probabilistic analysis and hydrologic risk into the overall design. This was accomplished through the development of a frequency analysis module. The frequency analysis module allows SLB design event magnitudes to be calculated based on the hydrologic return period. The multiobjective decision and freqeuncy anslysis modules were integrated in a decision support system (DSS) framework, SLEUTH (Shallow Landfill Evaluation Using Transport and Hydrology). SLEUTH is a Microsoft Windows {trademark} application, and is written in the Knowledge Pro Windows (Knowledge Garden, Inc., 1991) development language.

  18. Controlled landfill project, Yolo County, California

    Energy Technology Data Exchange (ETDEWEB)

    Augenstein, D.C.; Benemann, J.R. [Inst. for Environmental Management Inc., Palo Alto, CA (United States); Yazdani, R.; Kieffer, J.; Akau, H. [Yolo County Dept. of Public Works, Woodland, CA (United States)

    2004-07-01

    Controlled bioreactor landfill tests were conducted at the Central Landfill in Yolo County, California to determine how to maximize methane recovery for energy use while minimizing methane emissions to the atmosphere. Landfill gas has the potential to contribute 1 per cent to the total electricity supplies in the United States. The failure to use methane to its potential is due to unpredictability, variability and slow rates of production and low recovery factors of landfill methane. The main challenge lies in accelerating the biological decomposition and treatment of the municipal solid waste (MSW). The breakdown rate of MWS can be increased through the use of basic landfill biochemical engineering methods. This study demonstrated the influence of adding supplemental water and leachate to the MSW. Moisture, temperature and gas pressures were recorded throughout the waste mass. This study also focused on eliminating volatile organic compounds, reducing the costs for post-closure landfill care, improving the economics of scale for energy use, improving leachate quality and reducing the costs for off-site disposal of landfill leachate. It was shown that methane capture was maximized when a surface membrane was placed over a permeable layer and when the bioreactor was operated at a slight vacuum. Accelerated methane production and waste reduction were noted in the enhanced test cell. The first order rate constant for methanogenesis was about 0.45 per year. The control cell stopped producing gas after one year. 12 refs., 4 figs.

  19. Design of a GIS-based rating protocol to assess the potential for landfill closure using dredge material in post Hurricane Sandy New Jersey.

    Science.gov (United States)

    Miskewitz, Robert J; Barone, Daniel; Guterl, Sar J; Uchrin, Christopher G

    2017-05-12

    New Jersey is rapidly running out of capacity for storage of dredged material. A potential solution to this lack of storage space is to remove and reuse the dredged material for some beneficial use. Results from a Rutgers University project performed for the New Jersey Department of Transportation, Office of Maritime Resources, designed to assess the potential for closure of New Jersey landfills using dredge material from existing Confined Disposal Facilities (CDFs) are presented and discussed. The project included an update of the existing NJDEP landfill database, the development of a rating system to identify landfills with the highest potential to utilize dredged material for their closure, and the identification and preliminary investigation of the top candidate landfills based on this rating system.

  20. Bioreactor rotating wall vessel

    Science.gov (United States)

    2001-01-01

    The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Cell constructs grown in a rotating bioreactor on Earth (left) eventually become too large to stay suspended in the nutrient media. In the microgravity of orbit, the cells stay suspended. Rotation then is needed for gentle stirring to replenish the media around the cells.

  1. Bioreactor rotating wall vessel

    Science.gov (United States)

    2001-01-01

    The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Cell constructs grown in a rotating bioreactor on Earth (left) eventually become too large to stay suspended in the nutrient media. In the microgravity of orbit, the cells stay suspended. Rotation then is needed for gentle stirring to replenish the media around the cells.

  2. Space Bioreactor Science Workshop

    Science.gov (United States)

    Morrison, Dennis R. (Editor)

    1987-01-01

    The first space bioreactor has been designed for microprocessor control, no gaseous headspace, circulation and resupply of culture medium, and a slow mixing in very low shear regimes. Various ground based bioreactors are being used to test reactor vessel design, on-line sensors, effects of shear, nutrient supply, and waste removal from continuous culture of human cells attached to microcarriers. The small (500 ml) bioreactor is being constructed for flight experiments in the Shuttle middeck to verify systems operation under microgravity conditions and to measure the efficiencies of mass transport, gas transfer, oxygen consumption, and control of low shear stress on cells. Applications of microcarrier cultures, development of the first space bioreactor flight system, shear and mixing effects on cells, process control, and methods to monitor cell metabolism and nutrient requirements are among the topics covered.

  3. Design and Use of a Novel Bioreactor for Regeneration of Biaxially Stretched Tissue-Engineered Vessels.

    Science.gov (United States)

    Huang, Angela Hai; Lee, Yong-Ung; Calle, Elizabeth A; Boyle, Michael; Starcher, Barry C; Humphrey, Jay D; Niklason, Laura E

    2015-08-01

    Conventional bioreactors are used to enhance extracellular matrix (ECM) production and mechanical strength of tissue-engineered vessels (TEVs) by applying circumferential strain, which is uniaxial stretching. However, the resulting TEVs still suffer from inadequate mechanical properties, where rupture strengths and compliance values are still very different from native arteries. The biomechanical milieu of native arteries consists of both circumferential and axial loading. Therefore, to better simulate the physiological stresses acting on native arteries, we built a novel bioreactor system to enable biaxial stretching of engineered arteries during culture. This new bioreactor system allows for independent control of circumferential and axial stretching parameters, such as displacement and beat rate. The assembly and setup processes for this biaxial bioreactor system are reliable with a success rate greater than 75% for completion of long-term sterile culture. This bioreactor also supports side-by-side assessments of TEVs that are cultured under three types of mechanical conditions (static, uniaxial, and biaxial), all within the same biochemical environment. Using this bioreactor, we examined the impact of biaxial stretching on arterial wall remodeling of TEVs. Biaxial TEVs developed the greatest wall thickness compared with static and uniaxial TEVs. Unlike uniaxial loading, biaxial loading led to undulated collagen fibers that are commonly found in native arteries. More importantly, the biaxial TEVs developed the most mature elastin in the ECM, both qualitatively and quantitatively. The presence of mature extracellular elastin along with the undulated collagen fibers may contribute to the observed vascular compliance in the biaxial TEVs. The current work shows that biaxial stretching is a novel and promising means to improve TEV generation. Furthermore, this novel system allows us to optimize biomechanical conditioning by unraveling the interrelationships among the

  4. Design, characterization and application of the Multiple Air-lift Loop bioreactor.

    NARCIS (Netherlands)

    Bakker, W.A.M.

    1995-01-01

    A new bioreactor is introduced: the Multiple Air-lift Loop reactor (MAL). The MAL consists of a series of air-lift loop reactors within one vessel. With the MAL, a new type of geometry for air-lift reactors with an internal loop is introduced. This new geometry was characterized with respect to hydr

  5. Design, characterization and application of the multiple air-lift loop bioreactor

    NARCIS (Netherlands)

    Bakker, W.A.M.

    1995-01-01

    A new bioreactor is introduced: the Multiple Air-lift Loop reactor (MAL). The MAL consists of a series of air-lift loop reactors within one vessel. With the MAL, a new type of geometry for air-lift reactors with an internal loop is introduced. This new geometry was characterized with

  6. A method for designing configurations of nested monitoring wells near landfills

    Science.gov (United States)

    Hudak, Paul F.

    A method was devised for designing configurations of monitoring wells, consisting of vertically nested intakes in boreholes. The network-design method involves analyzing a subset of potential contaminant plumes emerging from the downgradient margin of a landfill. Plume widths are evaluated along selected equipotential lines and compared to the lengths of those lines. The method was applied to a 32-ha solid-waste landfill in Tarrant County, Texas, USA. Sixtynine potential source nodes were considered. A 15-borehole network devised by the method registered 93 detections in total, detecting all 69 model-generated plumes by at least one borehole. Based on an enumeration procedure, a minimum of 10 boreholes was needed to detect all of the model-generated plumes. However, the less conservative 10-borehole network had little capability for backup detection. An existing monitoring network of seven downgradient wells detected only 38 model-generated plumes. Results of this study illustrate a practical need for structured approaches to designing detection-based groundwater-monitoring configurations. Résumé Une méthode a été développée pour fournir les caractéristiques de puits de surveillance, avec des points de prélèvements superposés en forage. La méthode de réalisation du réseau s'appuie sur l'analyse d'un ensemble de panaches de pollution potentiels provenant du bord en aval d'une décharge. Les largeurs de panache sont estimées le long d'isopièzes sélectionnées et sont comparées à leur longueur. Cette méthode a été appliquée à une décharge de déchets solides couvrant 32ha, dans le canton de Tarrant (Texas, Etats-Unis). 69 noeuds de source potentielle de pollution ont été pris en compte. Un réseau de 15 forages, défini par la méthode, a enregistré au total 93 alarmes, détectant les 69 panaches simulés dans au moins un forage. Une procédure de dénombrement précise qu'un minimum de 10 forages est nécessaire pour détecter tous les

  7. Use of CFD for static sampling hood design: An example for methane flux assessment on landfill surfaces.

    Science.gov (United States)

    Lucernoni, Federico; Rizzotto, Matteo; Tapparo, Federica; Capelli, Laura; Sironi, Selena; Busini, Valentina

    2016-11-01

    The work focuses on the principles for the design of a specific static hood and on the definition of an optimal sampling procedure for the assessment of landfill gas (LFG) surface emissions. This is carried out by means of computational fluid dynamics (CFD) simulations to investigate the fluid dynamics conditions of the hood. The study proves that understanding the fluid dynamic conditions is fundamental in order to understand the sampling results and correctly interpret the measured concentration values by relating them to a suitable LFG emission model, and therefore to estimate emission rates. For this reason, CFD is a useful tool for the design and evaluation of sampling systems, among others, to verify the fundamental hypotheses on which the mass balance for the sampling hood is defined. The procedure here discussed, which is specific for the case of the investigated landfill, can be generalized to be applied also to different scenarios, where hood sampling is involved. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. ON THE DESIGN OF A NEURO-FUZZY CONTROLLER - APPLICATION TO THE CONTROL OF A BIOREACTOR

    Institute of Scientific and Technical Information of China (English)

    Joseph HAGGEGE; Mohamed BENREJEB; Pierre BORNE

    2005-01-01

    This paper presents a new methodological approach for the synthesis of a neuro-fuzzy controller,using an on-line learning procedure. A simple algebraic formulation of a Sugeno fuzzy inference system that ensures a coherent universe of discourse, making easy its interpretation by a human being,is proposed and implemented in the case of the control of a bioreactor, which is considered as a complex non linear process.

  9. Design Aspects of Bioreactors for Solid-state Fermentation: A Review

    OpenAIRE

    Ali, H. Kh. Q.; Zulkali, M.M.D.

    2011-01-01

    Solid-state fermentation has gained renewed attention, not only from researchers but also from industries, due to several advantages over submerged fermentations. This is partly because solid-state fermentation has lower energy requirements, higher yields, produces less wastewater with less risk of bacterial contamination, and partly because of environmental concerns regarding the disposal of solid wastes. This paper reviews different types of bioreactors that have been used for various purpo...

  10. Engineering Parameters in Bioreactor's Design: A Critical Aspect in Tissue Engineering

    Science.gov (United States)

    Amoabediny, Ghassem; Pouran, Behdad; Tabesh, Hadi; Shokrgozar, Mohammad Ali; Haghighipour, Nooshin; Khatibi, Nahid; Mottaghy, Khosrow; Zandieh-Doulabi, Behrouz

    2013-01-01

    Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors. PMID:24000327

  11. Engineering parameters in bioreactor's design: a critical aspect in tissue engineering.

    Science.gov (United States)

    Salehi-Nik, Nasim; Amoabediny, Ghassem; Pouran, Behdad; Tabesh, Hadi; Shokrgozar, Mohammad Ali; Haghighipour, Nooshin; Khatibi, Nahid; Anisi, Fatemeh; Mottaghy, Khosrow; Zandieh-Doulabi, Behrouz

    2013-01-01

    Bioreactors are important inevitable part of any tissue engineering (TE) strategy as they aid the construction of three-dimensional functional tissues. Since the ultimate aim of a bioreactor is to create a biological product, the engineering parameters, for example, internal and external mass transfer, fluid velocity, shear stress, electrical current distribution, and so forth, are worth to be thoroughly investigated. The effects of such engineering parameters on biological cultures have been addressed in only a few preceding studies. Furthermore, it would be highly inefficient to determine the optimal engineering parameters by trial and error method. A solution is provided by emerging modeling and computational tools and by analyzing oxygen, carbon dioxide, and nutrient and metabolism waste material transports, which can simulate and predict the experimental results. Discovering the optimal engineering parameters is crucial not only to reduce the cost and time of experiments, but also to enhance efficacy and functionality of the tissue construct. This review intends to provide an inclusive package of the engineering parameters together with their calculation procedure in addition to the modeling techniques in TE bioreactors.

  12. Membrane bioreactor for waste gas treatment

    NARCIS (Netherlands)

    Reij, M.W.

    1997-01-01

    Summary

    This thesis describes the design and testing of a membrane bioreactor (MBR) for removal of organic pollutants from air. In such a bioreactor for biological gas treatment pollutants are degraded by micro-organisms. The membrane bioreactor is an alternative to other types of

  13. Quality-by-Design approach to monitor the operation of a batch bioreactor in an industrial avian vaccine manufacturing process.

    Science.gov (United States)

    Largoni, Martina; Facco, Pierantonio; Bernini, Donatella; Bezzo, Fabrizio; Barolo, Massimiliano

    2015-10-10

    Monitoring batch bioreactors is a complex task, due to the fact that several sources of variability can affect a running batch and impact on the final product quality. Additionally, the product quality itself may not be measurable on line, but requires sampling and lab analysis taking several days to be completed. In this study we show that, by using appropriate process analytical technology tools, the operation of an industrial batch bioreactor used in avian vaccine manufacturing can be effectively monitored as the batch progresses. Multivariate statistical models are built from historical databases of batches already completed, and they are used to enable the real time identification of the variability sources, to reliably predict the final product quality, and to improve process understanding, paving the way to a reduction of final product rejections, as well as to a reduction of the product cycle time. It is also shown that the product quality "builds up" mainly during the first half of a batch, suggesting on the one side that reducing the variability during this period is crucial, and on the other side that the batch length can possibly be shortened. Overall, the study demonstrates that, by using a Quality-by-Design approach centered on the appropriate use of mathematical modeling, quality can indeed be built "by design" into the final product, whereas the role of end-point product testing can progressively reduce its importance in product manufacturing.

  14. State of the art design: A closure system for the largest hazardous waste landfill at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Bartlett, S.F.; Serrato, M.G.; McMullin, S.R.

    1992-12-31

    This paper discusses the cover system proposed for a 55-acre, hazardous waste closure of the sanitary landfill at the Savannah River Site, near Aiken, South Carolina. The proposed cover system has been designed to accommodate a significant amount of post-closure settlement while maintaining a permeability of 1 {times} 10{sup {minus}7} cm/s or less throughout its 30-year, regulatory lifetime. A composite cover consisting of a geomembrane (GM) underlain by a geosynthetic clay liner (GCL) was selected because of its extremely low permeability, ability to elongate without tearing, and capacity to ``self-heal`` if punctured. These characteristics will enable the cover system to accommodate differential settlement without cracking or tearing, this providing long-term protection with minimal maintenance. Also, to improve the ability of the cover system to span voids that may develop in the underlying waste, a geogrid has been included in the foundation layer. A gas vent layer has been included to allow for the safe collection and venting of landfill gases.

  15. State of the art design: A closure system for the largest hazardous waste landfill at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Bartlett, S.F.; Serrato, M.G.; McMullin, S.R.

    1992-01-01

    This paper discusses the cover system proposed for a 55-acre, hazardous waste closure of the sanitary landfill at the Savannah River Site, near Aiken, South Carolina. The proposed cover system has been designed to accommodate a significant amount of post-closure settlement while maintaining a permeability of 1 [times] 10[sup [minus]7] cm/s or less throughout its 30-year, regulatory lifetime. A composite cover consisting of a geomembrane (GM) underlain by a geosynthetic clay liner (GCL) was selected because of its extremely low permeability, ability to elongate without tearing, and capacity to self-heal'' if punctured. These characteristics will enable the cover system to accommodate differential settlement without cracking or tearing, this providing long-term protection with minimal maintenance. Also, to improve the ability of the cover system to span voids that may develop in the underlying waste, a geogrid has been included in the foundation layer. A gas vent layer has been included to allow for the safe collection and venting of landfill gases.

  16. Design for Deconstruction (DfD): Critical success factors for diverting end-of-life waste from landfills.

    Science.gov (United States)

    Akinade, Olugbenga O; Oyedele, Lukumon O; Ajayi, Saheed O; Bilal, Muhammad; Alaka, Hafiz A; Owolabi, Hakeem A; Bello, Sururah A; Jaiyeoba, Babatunde E; Kadiri, Kabir O

    2017-02-01

    The aim of this paper is to identify Critical Success Factors (CSF) needed for effective material recovery through Design for Deconstruction (DfD). The research approach employed in this paper is based on a sequential exploratory mixed method strategy. After a thorough review of literature and conducting four Focus Group Discussion (FGDs), 43 DfD factors were identified and put together in a questionnaire survey. Data analyses include Cronbach's alpha reliability analysis, mean testing using significance index, and exploratory factor analysis. The result of the factor analysis reveals that an underlying factor structure of five DfD factors groups that include 'stringent legislation and policy', 'deconstruction design process and competencies', 'design for material recovery', 'design for material reuse', and 'design for building flexibility'. These groups of DfD factor groups show that the requirements for DfD goes beyond technical competencies and that non-technical factors such as stringent legislation and policy and design process and competency for deconstruction are key in designing deconstructable buildings. Paying attention to the factors identified in all of these categories will help to tackle impediments that could hinder the effectiveness of DfD. The results of this study would help design and project managers to understand areas of possible improvement in employing DfD as a strategy for diverting waste from landfills. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Effects of exogenous aerobic bacteria on methane production and biodegradation of municipal solid waste in bioreactors.

    Science.gov (United States)

    Ge, Sai; Liu, Lei; Xue, Qiang; Yuan, Zhiming

    2016-09-01

    Landfill is the most common and efficient ways of municipal solid waste (MSW) disposal and the landfill biogas, mostly methane, is currently utilized to generate electricity and heat. The aim of this work is to study the effects and the role of exogenous aerobic bacteria mixture (EABM) on methane production and biodegradation of MSW in bioreactors. The results showed that the addition of EABM could effectively enhance hydrolysis and acidogenesis processes of MSW degradation, resulting in 63.95% reduction of volatile solid (VS), the highest methane production rate (89.83Lkg(-1) organic matter) ever recorded and a threefold increase in accumulative methane production (362.9L) than the control (127.1L). In addition, it is demonstrated that white-rot fungi (WRF) might further promote the methane production through highly decomposing lignin, but the lower pH value in leachate and longer acidogenesis duration may cause methane production reduced. The data demonstrated that methane production and biodegradation of MSW in bioreactors could be significantly enhanced by EABM via enhanced hydrolysis and acidogenesis processes, and the results are of great economic importance for the future design and management of landfill.

  18. Design, characterization and application of the Multiple Air-lift Loop bioreactor.

    OpenAIRE

    Bakker, W.A.M.

    1995-01-01

    A new bioreactor is introduced: the Multiple Air-lift Loop reactor (MAL). The MAL consists of a series of air-lift loop reactors within one vessel. With the MAL, a new type of geometry for air-lift reactors with an internal loop is introduced. This new geometry was characterized with respect to hydrodynamics, mixing and oxygen transfer. The hydrodynamics were described by an existing model. Hydrodynamics, mixing and oxygen transfer in the new reactor configuration were comparable to that in c...

  19. Landfill gas

    Energy Technology Data Exchange (ETDEWEB)

    Willumsen, H. (Crone and Koch, Viborg (Denmark))

    1990-08-01

    In most landfills, the refuse deposit usually has a high content of organic matter consisting of a mixture of household, industrial and garden waste. Immediately after the refuse has been placed in the landfill, aerobic decomposition of the organic waste begins. Once the oxygen has been exhausted, anaerobic decomposition begins. 'Biogas' is produced which has a methane content of approximately 50% and can be used as a fuel. The exploitation of landfill gas for energy purposes was initiated in the USA around 1975 and later in Europe. A landfill gas plant consists of a recovery system and a production system. A recovery system can consist of vertical perforated pipe wells, horizontal perforated pipes or ditches, or membrane covers to collect the generated gas. Under normal conditions it will not be necessary to process the gas except for the removal of water and other impurities (e.g. solid particles) if the gas is to be used in a boiler or engine. In the USA most often only power is produced, whereas in Europe the waste heat is normally exploited, making the plant function as a combined power and heating plant. It is also possible to upgrade the landfill gas to a methane content of nearly 100, after which it can be distributed with natural gas. There are several such plants in the USA. 8 refs., 6 figs., 6 tabs.

  20. Study of anaerobic ammonium oxidation bacterial community in the aged refuse bioreactor with 16S rRNA gene library technique.

    Science.gov (United States)

    Wang, Chao; Xie, Bing; Han, Lu; Xu, Xiaofan

    2013-10-01

    In order to investigate the anaerobic ammonium-oxidation (Anammox) nitrogen removal pathway of the aged refuse bioreactor treating landfill leachate, a lab-scale bioreactor was established and run for 35 weeks, the performance of the bioreactor and its bacterial community structure of Planctomycetes were analyzed. The results showed that the average TN removal rate of landfill leachate could be reached to 89%. 16S rRNA gene library of Planctomycetes revealed that Anammox sequences accounted for 28.3% of the total Planctomycetes sequences in the bioreactor, and previously recognized Anammox bacterium Candidatus Kuenenia stuttgartiensis was the only detected Anammox species in the reactor. It was also found that Anammox bacteria distributed at different sites of the bioreactor while mostly concentrated in the middle and low-middle part. Results above confirmed that Anammox process could happen in aged refuse bioreactor treating landfill leachate and provided an alternative nitrogen removal pathway in practical landfills.

  1. NASA Bioreactor Schematic

    Science.gov (United States)

    2001-01-01

    The schematic depicts the major elements and flow patterns inside the NASA Bioreactor system. Waste and fresh medium are contained in plastic bags placed side-by-side so the waste bag fills as the fresh medium bag is depleted. The compliance vessel contains a bladder to accommodate pressure transients that might damage the system. A peristolic pump moves fluid by squeezing the plastic tubing, thus avoiding potential contamination. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  2. NASA Bioreactor Schematic

    Science.gov (United States)

    2001-01-01

    The schematic depicts the major elements and flow patterns inside the NASA Bioreactor system. Waste and fresh medium are contained in plastic bags placed side-by-side so the waste bag fills as the fresh medium bag is depleted. The compliance vessel contains a bladder to accommodate pressure transients that might damage the system. A peristolic pump moves fluid by squeezing the plastic tubing, thus avoiding potential contamination. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  3. Gaseous methyl- and inorganic mercury in landfill gas from landfills in Florida, Minnesota, Delaware, and California

    Science.gov (United States)

    Lindberg, S. E.; Southworth, G.; Prestbo, E. M.; Wallschläger, D.; Bogle, M. A.; Price, J.

    2005-01-01

    Municipal waste landfills contain numerous sources of mercury which could be emitted to the atmosphere. Their generation of methane by anaerobic bacteria suggests that landfills may act as bioreactors for methylated mercury compounds. Since our previous study at a single Florida landfill, gaseous inorganic and methylated mercury species have now been identified and quantified in landfill gas at nine additional municipal landfills in several regions of the US. Total gaseous mercury occurs at concentrations in the μg m-3 range, while methylated compounds occur at concentrations in the ng m-3 range at all but one of the landfill sites. Dimethylmercury is the predominant methylated species, at concentrations up to 100 ng m-3, while monomethyl mercury was generally lower. Limited measurements near sites where waste is exposed for processing (e.g. working face, transfer areas) suggest that dimethylmercury is released during these activities as well. Although increasing amounts of landfill gas generated in the US are flared (which should thermally decompose the organic mercury to inorganic mercury), unflared landfill gas is a potentially important anthropogenic source of methylated mercury emissions to the atmosphere.

  4. Bioreactors and bioseparation.

    Science.gov (United States)

    Zhang, Siliang; Cao, Xuejun; Chu, Ju; Qian, Jiangchao; Zhuang, Yingping

    2010-01-01

    Along with the rapid development of life science, great attention has been increasingly given to the biotechnological products of cell cultivation technology. In the course of industrialization, bioreactor and bioproduct separation techniques are the two essential technical platforms. In this chapter, the current situation and development prospects of bioreactor techniques in China are systematically discussed, starting with the elucidation of bioreactor processes and the principle of process optimization. Separation technology for biological products is also briefly introduced.At present, a series of bioreactors made by Chinese enterprises have been widely used for laboratory microbial cultivation, process optimization studies, and large-scale production. In the course of bioprocess optimization studies, the complicated bioprocesses in a bioreactor could be resolved into different reaction processes on three scales, namely genetic, cellular, and bioreactor scales. The structural varieties and nonlinear features of various scales of bioprocess systems was discussed through considering the mutual effects of different scale events, namely material flux, energy flux, and information flux, and the optimization approach for bioprocesses was proposed by taking the analysis of metabolic flux and multiscale consideration as a core strategy.In order to realize such an optimization approach, a bioreactor system based on association analysis of multiscale parameters was elaborated, and process optimization of many biological products were materialized, which resulted in great improvement in production efficiency. In designing and manufacturing large-scale bioreactors, the principle of scaling up a process incorporated with flow field study and physiological features in a bioreactor was suggested according to the criterion for the scale-up of cellular physiological and metabolic traits. The flow field features of a bioreactor were investigated through computational fluid

  5. Aortic valve biomechanics during LVAD support: Implementation in a bioreactor design and preliminary testing

    Science.gov (United States)

    Jamal, Madiha

    Although Left Ventricle Assist Device (LVAD) support has enhanced the quality of life for many heart failure patients, its prolonged in-vivo implantation causes change in hemodynamics and biomechanics of the aortic heart valve eventually leading to development of aortic insufficiency (AI). The LVAD decreases pressure in the left ventricle, leading to high transvalvular pressure and reduced aortic valve opening. Our hypothesis is that the increased pressure leads to increased mechanical stretch in the aortic valve leaflets, inducing a cascade of responses that ultimately result in local tissue fibrosis and AI. The goal of this study is to investigate the mechanism behind this hypothesis using the methods of tissue engineering. A bioreactor has been built that imparts cyclic stretch and flow to small 3-D constructs of living cells cultured in a silicone membrane. The approach is to use this device for in vitro tissue culture of vascular interstitial cells (VICs) embedded in a collagen gel, which will be subjected to normal and altered stretch and shear representative of the in vivo valve biomechanics. The bioreactor was validated to measure the amount of stretch and shear it can impart to closely replicate in-vivo conditions using PIV technique and ImageJ software. Mean longitudinal strain of 0.037cm (SD= +/-0.013cm) was recorded with mean perpendicular strain being 0.0046cm (SD= +/-0.0169cm). Measured average shear stress imparted at 100ml/min was 2.735 dynes/cm2 (SD= +/-2.25 dynes/cm2) with 6.21 dynes/cm2 (SD= +/-3.35 dynes/cm2) at 200ml/min. The cells that underwent cycles of stretch and shear in the bioreactor were screened for formation of myofibroblast using techniques of immunohistochemistry. The marker used was ? smooth muscle actin (SMA) which identifies pathological differentiation of the CPCs to myofibroblast. Yhe expression of the myofibroblast phenotype is a feature of valvupathy. In case of Shear Vs Static control, the mean value for SMA expression for

  6. Application of bioreactor design principles and multivariate analysis for development of cell culture scale down models.

    Science.gov (United States)

    Tescione, Lia; Lambropoulos, James; Paranandi, Madhava Ram; Makagiansar, Helena; Ryll, Thomas

    2015-01-01

    A bench scale cell culture model representative of manufacturing scale (2,000 L) was developed based on oxygen mass transfer principles, for a CHO-based process producing a recombinant human protein. Cell culture performance differences across scales are characterized most often by sub-optimal performance in manufacturing scale bioreactors. By contrast in this study, reduced growth rates were observed at bench scale during the initial model development. Bioreactor models based on power per unit volume (P/V), volumetric mass transfer coefficient (kL a), and oxygen transfer rate (OTR) were evaluated to address this scale performance difference. Lower viable cell densities observed for the P/V model were attributed to higher sparge rates and reduced oxygen mass transfer efficiency (kL a) of the small scale hole spargers. Increasing the sparger kL a by decreasing the pore size resulted in a further decrease in growth at bench scale. Due to sensitivity of the cell line to gas sparge rate and bubble size that was revealed by the P/V and kL a models, an OTR model based on oxygen enrichment and increased P/V was selected that generated endpoint sparge rates representative of 2,000 L scale. This final bench scale model generated similar growth rates as manufacturing. In order to take into account other routinely monitored process parameters besides growth, a multivariate statistical approach was applied to demonstrate validity of the small scale model. After the model was selected based on univariate and multivariate analysis, product quality was generated and verified to fall within the 95% confidence limit of the multivariate model.

  7. 40 CFR 63.1947 - When do I have to comply with this subpart if I own or operate a bioreactor?

    Science.gov (United States)

    2010-07-01

    ... subpart if I own or operate a bioreactor? 63.1947 Section 63.1947 Protection of Environment ENVIRONMENTAL... or operate a bioreactor? You must comply with this subpart by the dates specified in § 63.1945(a) or (b) of this subpart. If you own or operate a bioreactor located at a landfill that is not permanently...

  8. Stability analysis criteria in landfill design based on the Spanish code; Criterios de estabilidad en el diseno de un vertedero, basado en la normativa espanola

    Energy Technology Data Exchange (ETDEWEB)

    Estaire Gepp, J.; Pardo de Santayana, F.

    2014-02-01

    The design of a landfill requires performing stability analyses. To perform such analyses it is necessary to define different design situations and their corresponding safety factors. Geo synthetics are normally used to construct the lining system of the landfills, causing critical slip surfaces to pass along one of the different geo synthetic interfaces. Determination of the shear strength of such critical interfaces is, therefore, an extremely important issue. In this paper, these aspects are analysed based on what is set in the Spanish codes and in the technical literature. As a result of the study, some tables are presented which relate the different design situations (normal, accidental or extraordinary) to the shear strength of the lining system to be used (peak or residual) and define the minimum factor of safety to be accomplished. (Author)

  9. Design for a bioreactor with sunlight supply and operations systems for use in the space environment

    Science.gov (United States)

    Mori, Kei; Ohya, Haruhiko; Matsumoto, Kanji; Furuune, Hiroyuki; Isozaki, Kyôko; Siekmeier, Peter

    An experiment was carried out to determine the characteristics of an operations system that can support fast cultivation of algae at high densities in the weightlessness of space. The experiment was conducted in glass bioreactor tanks, in which light was supplied by radiator rods connected to optical fiber cables. The illumination areas of the tanks were 2600 cm2, 6000 cm2, and 9200 cm2 per liter of solution. The characteristics of O2-CO2 gas exchange, concentration and separation of chlorella in the growth medium, dialysis of ionic salts in the growth medium, etc. were examined. Chlorella ellipsoidea was used in the experiment, yielding the following results: o (1)By increasing the ratio of illumination area to volume, growth rates of up to approximately 0.6 g/L.h could be obtained in a highly concentrated solution (one that contains 20 g/L or more of algae). (2)The most suitable proportions of carbon dioxide and oxygen gases for growing algae quickly at high concentrations were found to be 10% CO2 and 10% O2 (by volume). (3)There was a high optimum concentration for fast cultivation, and the data obtained resembled the theoretical curve postulated by P. Behrens et al. (4)It was possible to exchange carbon dioxide and oxygen using gas-permeable membrane modules. (5)It was possible to separare the chlorella from the growth medium and recycle the medium.

  10. Effect of Injected Leachate C/N Ratio on the Denitrification of a Bioreactor Filled with Landfilled Refuse%回灌渗滤液C/N对填埋垃圾生物反应器反硝化特性的影响

    Institute of Scientific and Technical Information of China (English)

    黎乾; 吴松维; 吴伟祥; 孙法迁; 刘晶静; 蔡传钰; 陈敏

    2011-01-01

    The denitrification capacity of a landfill bioreactor was investigated under different ratios of injected leachate C/N;the denitrifying bacteria community compositions over four injection times were also studied using molecular approaches and functional gene nirS served as marker.Results showed that COD/NO-3-N ratio of the injected landfill leachate had a significant impact on the denitrification capacity of the bioreactor.Nitrate reduction rate increased from 1.14 mg·(kg·h)-1 to 11.40 mg mg·(kg·h)-1 when the injected leachate COD/NO-3-N ratio raised from 3.11 to 13.08.It suggested that a stable and rapid denitrification could be obtained when bioavailable COD/NO-3-N ratio in the injected leachate was 6.37.In the bioreactor,the main denitrifying bacteria was similar to β-proteobacteria,and others belonged to uncultured bacteria.Thiobacillus denitrificans and Azoarcus tolulyticus known as β-proteobacteria were the dominant species and played an important role in NO-3-N consumption during the leachate injection.%利用模拟填埋垃圾生物反应器(landfill bioreactor)研究了回灌渗滤液C/N对填埋垃圾堆体反硝化性能的影响,并采用PCR扩增、克隆测序等分子生物学技术,以功能基因nirS为分子标记考察了4次回灌过程中反应器内反硝化微生物群落结构变化.结果表明,回灌渗滤液的COD/NO 3--N比例对反应器的反硝化活性具有显著性影响.当COD/NO 3--N从3.11提高到13.08时,反应器内硝酸盐还原速率可从1.14 mg.(kg.h)-1提高到11.40 mg.(kg.h)-1.当回灌渗滤液生物可利用性COD与NO 3--N比值达到6.37时,可以实现填埋垃圾生物反应器反硝化作用的快速、稳定运行.4次回灌,反应器内的反硝化微生物大部分与β-变形菌纲(β-proteobacteria)细菌相似,少数属于非培养微生物(uncultured bacteria),其中Thiobacillus denitrificans和Azoarcus tolulyticus是反硝化过程的主要功能微生物,在回灌渗

  11. NASA Bioreactor tissue culture

    Science.gov (United States)

    1998-01-01

    Dr. Lisa E. Freed of the Massachusetts Institute of Technology and her colleagues have reported that initially disc-like specimens tend to become spherical in space, demonstrating that tissues can grow and differentiate into distinct structures in microgravity. The Mir Increment 3 (Sept. 16, 1996 - Jan. 22, 1997) samples were smaller, more spherical, and mechanically weaker than Earth-grown control samples. These results demonstrate the feasibility of microgravity tissue engineering and may have implications for long human space voyages and for treating musculoskeletal disorders on earth. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  12. NASA Bioreactor tissue culture

    Science.gov (United States)

    1998-01-01

    Dr. Lisa E. Freed of the Massachusetts Institute of Technology and her colleagues have reported that initially disc-like specimens tend to become spherical in space, demonstrating that tissues can grow and differentiate into distinct structures in microgravity. The Mir Increment 3 (Sept. 16, 1996 - Jan. 22, 1997) samples were smaller, more spherical, and mechanically weaker than Earth-grown control samples. These results demonstrate the feasibility of microgravity tissue engineering and may have implications for long human space voyages and for treating musculoskeletal disorders on earth. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  13. The Novel Design and Manufacturing Technology of Densified RDF from Reclaimed Landfill without a Mixing Binding Agent Using a Hydraulic Hot Pressing Machine

    Directory of Open Access Journals (Sweden)

    Kerdsuwan Somrat

    2016-01-01

    Full Text Available The manufacturing of RDF (Refuse Derived Fuel from a conventional cold press extrusion machine is not suitable for producing RDF from reclaimed landfill since it is not identical in shape and form after production due to the swelling of the plastic fraction contained inside the reclaimed landfill and hence needs a very high compression force. Moreover, a binder agent is needed in order to keep the RDF in a similar shape and form. A novel design and manufacturing technology for a hydraulic hot pressing machine has been established and can produce high-quality RDF without any binder. The two electrical heaters are installed at the inner core and on the surface of the mold. The compression force on the mold is performed by a hydraulic jack. In addition, a newly-designed locking plate system which is designed by a slider to open and close along the paired horizontal slots, can reduce the cycle time of the manufacturing process and yield higher productivity. The testing properties of the RDF produced by the novel hydraulic hot pressing machine include the examination of size, shape, weight, unit density, bulk density, compression strength, moisture content, and heating value. The results showed that the RDF is suitable to be used as feedstock in an incinerator or gasifier to produce green and clean energy from reclaimed landfill.

  14. Cells growing in NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    For 5 days on the STS-70 mission, a bioreactor cultivated human colon cancer cells, which grew to 30 times the volume of control specimens grown on Earth. This significant result was reproduced on STS-85 which grew mature structures that more closely match what are found in tumors in humans. Shown here, clusters of cells slowly spin inside a bioreactor. On Earth, the cells continually fall through the buffer medium and never hit bottom. In space, they are naturally suspended. Rotation ensures gentle stirring so waste is removed and fresh nutrient and oxygen are supplied. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  15. Cells growing in NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    For 5 days on the STS-70 mission, a bioreactor cultivated human colon cancer cells, which grew to 30 times the volume of control specimens grown on Earth. This significant result was reproduced on STS-85 which grew mature structures that more closely match what are found in tumors in humans. Shown here, clusters of cells slowly spin inside a bioreactor. On Earth, the cells continually fall through the buffer medium and never hit bottom. In space, they are naturally suspended. Rotation ensures gentle stirring so waste is removed and fresh nutrient and oxygen are supplied. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  16. Landfills, Landfills, Published in 2003, Taylor County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Landfills dataset, was produced all or in part from Published Reports/Deeds information as of 2003. It is described as 'Landfills'. Data by this publisher are...

  17. Design and Test of a Low-Cost RGB Sensor for Online Measurement of Microalgae Concentration within a Photo-Bioreactor

    Directory of Open Access Journals (Sweden)

    Micaela Benavides

    2015-02-01

    Full Text Available In this study, a low-cost RGB sensor is developed to measure online the microalgae concentration within a photo-bioreactor. Two commercially available devices, i.e., a spectrophotometer for offline measurements and an immersed probe for online measurements, are used for calibration and comparison purposes. Furthermore, the potential of such a sensor for estimating other variables is illustrated with the design of an extended Luenberger observer.

  18. Transgenic bioreactors.

    Science.gov (United States)

    Jänne, J; Alhonen, L; Hyttinen, J M; Peura, T; Tolvanen, M; Korhonen, V P

    1998-01-01

    Since the generation of the first transgenic mice in 1980, transgene technology has also been successfully applied to large farm animals. Although this technology can be employed to improve certain production traits of livestock, this approach has not been very successful so far owing to unwanted effects encountered in the production animals. However, by using tissue-specific targeting of the transgene expression, it is possible to produce heterologous proteins in the extracellular space of large transgenic farm animals. Even though some recombinant proteins, such as human hemoglobin, have been produced in the blood of transgenic pigs, in the majority of the cases mammary gland targeted expression of the transgene has been employed. Using production genes driven by regulatory sequences of milk protein genes a number of valuable therapeutic proteins have been produced in the milk of transgenic bioreactors, ranging from rabbits to dairy cattle. Unlike bacterial fermentors, the mammary gland of transgenic bioreactors appear to carry out proper postsynthetic modifications of human proteins required for full biological activity. In comparison with mammalian cell bioreactors, transgenic livestock with mammary gland targeted expression seems to be able to produce valuable human therapeutic proteins at very low cost. Although not one transgenically produced therapeutic protein is yet on the market, the first such proteins have recently entered or even completed clinical trials required for their approval.

  19. DESIGN OF LANDFILL LEACHATE TREATMENT PLANT IN CHANGSHA SOLID WASTE LANDFILL SITE%长沙市固体废弃物处理场渗沥液处理工程

    Institute of Scientific and Technical Information of China (English)

    吴惠鹏; 周昭阳; 陈娟娟

    2012-01-01

    长沙市固体废弃物处理场渗沥液处理工程是目前国内达到垃圾填埋场污染物排放限制(GB 16889-2008)要求的大型渗沥液处理厂,于2010年6月建成,最大处理规模达到1500 t/d,采用(A/O)2-MBR+RO/NF处理工艺设计.经运行验证,处理系统稳定高效,出水水质良好达标.文中对工程概况、污水特点、工艺流程、单元设计及运行效果进行了说明,并对本项目设计经验进行了总结.%The leachate treatment plant in Changsha Solid Waste Landfill Site was a large-scale plant which final effluent can meet the requirements of GB 16889-2008: standard for pollution control on the landfill site of municipal solid waste. The plant was completed on June 2010, whose maximum handling capacity was 1 500 m3/d, which was designed by (A/O)2-MBR+RO/NF process. The practical running showed that the treatment system was reliable and efficient, the effluent water quality can meet the standard. This article introduced the treatment plant, influent water quality, treatment process and treatment effect, and summarized as well the experiences of the plant designing.

  20. Treatment of municipal landfill leachate by catalytic wet air oxidation: Assessment of the role of operating parameters by factorial design.

    Science.gov (United States)

    Anglada, Angela; Urtiaga, Ane; Ortiz, Inmaculada; Mantzavinos, Dionissios; Diamadopoulos, Evan

    2011-08-01

    The wet air oxidation (WAO) of municipal landfill leachate catalyzed by cupric ions and promoted by hydrogen peroxide was investigated. The effect of operating conditions such as WAO treatment time (15-30min), temperature (160-200°C), Cu(2+) concentration (250-750mgL(-1)) and H(2)O(2) concentration (0-1500mgL(-1)) on chemical oxygen demand (COD) removal was investigated by factorial design considering a two-stage, sequential process comprising the heating-up of the reactor and the actual WAO. The leachate, at an initial COD of 4920mgL(-1), was acidified to pH 3 leading to 31% COD decrease presumably due to the coagulation/precipitation of colloidal and other organic matter. During the 45min long heating-up period of the WAO reactor under an inert atmosphere, COD removal values up to 35% (based on the initial COD value) were recorded as a result of the catalytic decomposition of H(2)O(2) to reactive hydroxyl radicals. WAO at 2.5MPa oxygen partial pressure advanced treatment further; for example, 22min of oxidation at 200°C, 250mgL(-1) Cu(2+) and 0-1500mgL(-1) H(2)O(2) resulted in an overall (i.e. including acidification and heating-up) COD reduction of 78%. Amongst the operating variables in question, temperature had the strongest influence on both the heating-up and WAO stages, while H(2)O(2) concentration strongly affected the former and reaction time the latter. Nonetheless, the effects of temperature and H(2)O(2) concentration were found to depend on the concentration levels of catalyst as suggested by the significance of their 3rd order interaction term.

  1. Factorial design analysis for COD removal from landfill leachate by photoassisted Fered-Fenton process.

    Science.gov (United States)

    Wu, Xiaogang; Zhang, Hui; Li, Yanli; Zhang, Daobin; Li, Xianwang

    2014-01-01

    The Fered-Fenton process has been shown to be an effective method for leachate treatment, but it still faces problems of inadequate regeneration of ferrous ion. However, the use of the photoassisted Fered-Fenton process could overcome this difficulty and improve the efficiency of chemical oxygen demand (COD) removal since photoassisted Fered-Fenton process induces the production of hydroxyl radicals from the regeneration of ferrous ions and the reaction of hydrogen peroxide with UV light. As there are so many operating parameters in photoassisted Fered-Fenton process, it is necessary to develop a mathematical model in order to produce the most economical process. In the present study, a factorial design was carried out to evaluate leachate treatment by photoassisted Fered-Fenton process. The influence of the following variables: H₂O₂ concentration, Fe(2+) concentration, current density, and initial pH in the photoassisted Fered-Fenton process was investigated by measuring COD removal efficiencies after 60-min reaction. The relationship between COD removal and the most significant independent variables was established by means of an experimental design. The H₂O₂ concentration, Fe(2+) concentration, initial pH, and the interaction effect between current density and initial pH were all significant factors. The factorial design models were derived based on the COD removal efficiency results and the models fit the data well.

  2. An improvement of surfactin production by B. subtilis BBG131 using design of experiments in microbioreactors and continuous process in bubbleless membrane bioreactor.

    Science.gov (United States)

    Motta Dos Santos, Luiz Fernando; Coutte, François; Ravallec, Rozenn; Dhulster, Pascal; Tournier-Couturier, Lucie; Jacques, Philippe

    2016-10-01

    Culture medium elements were analysed by a screening DoE to identify their influence in surfactin specific production by a surfactin constitutive overproducing Bacillus subtilis strain. Statistics pointed the major enhancement caused by high glutamic acid concentrations, as well as a minor positive influence of tryptophan and glucose. Successively, a central composite design was performed in microplate bioreactors using a BioLector®, in which variations of these impressive parameters, glucose, glutamic acid and tryptophan concentrations were selected for optimization of product-biomass yield (YP/X). Results were exploited in combination with a RSM. In absolute terms, experiments attained an YP/X 3.28-fold higher than those obtained in Landy medium, a usual culture medium used for lipopeptide production by B. subtilis. Therefore, two medium compositions for enhancing biomass and surfactin specific production were proposed and tested in continuous regime in a bubbleless membrane bioreactor. An YP/X increase of 2.26-fold was observed in bioreactor scale.

  3. Bioreactors for Plant Embryogenesis and Beyond.

    Science.gov (United States)

    Fei, Liwen; Weathers, Pamela

    2016-01-01

    A variety of different bioreactors have been developed for use in initiating and cultivating somatic embryos. The various designs for embryogenesis and culture are critically evaluated here. Bioreactor optimization and operation methods are also described along with recommendations for use based on desired outcome.

  4. 40 CFR 60.752 - Standards for air emissions from municipal solid waste landfills.

    Science.gov (United States)

    2010-07-01

    ... municipal solid waste landfills. 60.752 Section 60.752 Protection of Environment ENVIRONMENTAL PROTECTION... of Performance for Municipal Solid Waste Landfills § 60.752 Standards for air emissions from municipal solid waste landfills. (a) Each owner or operator of an MSW landfill having a design capacity...

  5. Biological technologies for the removal of sulfur containing compounds from waste streams: bioreactors and microbial characteristics.

    Science.gov (United States)

    Li, Lin; Zhang, Jingying; Lin, Jian; Liu, Junxin

    2015-10-01

    Waste gases containing sulfur compounds, such as hydrogen sulfide, sulfur dioxide, thioethers, and mercaptan, produced and emitted from industrial processes, wastewater treatment, and landfill waste may cause undesirable issues in adjacent areas and contribute to atmospheric pollution. Their control has been an area of concern and research for many years. As alternative to conventional physicochemical air pollution control technologies, biological treatment processes which can transform sulfur compounds to harmless products by microbial activity, have gained in popularity due to their efficiency, cost-effectiveness and environmental acceptability. This paper provides an overview of the current biological techniques used for the treatment of air streams contaminated with sulfur compounds as well as the advances made in the past year. The discussion focuses on bioreactor configuration and design, mechanism of operation, insights into the overall biological treatment process, and the characterization of the microbial species present in bioreactors, their populations and their interactions with the environment. Some bioreactor case studies are also introduced. Finally, the perspectives on future research and development needs in this research area were also highlighted.

  6. Flow bioreactor design for quantitative measurements over endothelial cells using micro-particle image velocimetry

    Science.gov (United States)

    Leong, Chia Min; Voorhees, Abram; Nackman, Gary B.; Wei, Timothy

    2013-04-01

    Mechanotransduction in endothelial cells (ECs) is a highly complex process through which cells respond to changes in hemodynamic loading by generating biochemical signals involving gene and protein expression. To study the effects of mechanical loading on ECs in a controlled fashion, different in vitro devices have been designed to simulate or replicate various aspects of these physiological phenomena. This paper describes the design, use, and validation of a flow chamber which allows for spatially and temporally resolved micro-particle image velocimetry measurements of endothelial surface topography and stresses over living ECs immersed in pulsatile flow. This flow chamber also allows the study of co-cultures (i.e., ECs and smooth muscle cells) and the effect of different substrates (i.e., coverslip and/or polyethylene terepthalate (PET) membrane) on cellular response. In this report, the results of steady and pulsatile flow on fixed endothelial cells seeded on PET membrane and coverslip, respectively, are presented. Surface topography of ECs is computed from multiple two-dimensional flow measurements. The distributions of shear stress and wall pressure on each individual cell are also determined and the importance of both types of stress in cell remodeling is highlighted.

  7. Flow bioreactor design for quantitative measurements over endothelial cells using micro-particle image velocimetry.

    Science.gov (United States)

    Leong, Chia Min; Voorhees, Abram; Nackman, Gary B; Wei, Timothy

    2013-04-01

    Mechanotransduction in endothelial cells (ECs) is a highly complex process through which cells respond to changes in hemodynamic loading by generating biochemical signals involving gene and protein expression. To study the effects of mechanical loading on ECs in a controlled fashion, different in vitro devices have been designed to simulate or replicate various aspects of these physiological phenomena. This paper describes the design, use, and validation of a flow chamber which allows for spatially and temporally resolved micro-particle image velocimetry measurements of endothelial surface topography and stresses over living ECs immersed in pulsatile flow. This flow chamber also allows the study of co-cultures (i.e., ECs and smooth muscle cells) and the effect of different substrates (i.e., coverslip and∕or polyethylene terepthalate (PET) membrane) on cellular response. In this report, the results of steady and pulsatile flow on fixed endothelial cells seeded on PET membrane and coverslip, respectively, are presented. Surface topography of ECs is computed from multiple two-dimensional flow measurements. The distributions of shear stress and wall pressure on each individual cell are also determined and the importance of both types of stress in cell remodeling is highlighted.

  8. Experimental mixture design as a tool to enhance glycosyl hydrolases production by a new Trichoderma harzianum P49P11 strain cultivated under controlled bioreactor submerged fermentation.

    Science.gov (United States)

    Delabona, Priscila da Silva; Farinas, Cristiane Sanchez; Lima, Deise Juliana da Silva; Pradella, José Geraldo da Cruz

    2013-03-01

    This work investigates the glycosyl hydrolase (GH) profile of a new Trichoderma harzianum strain cultivated under controlled bioreactor submerged fermentation. The influence of different medium components (delignified steam-exploded sugarcane bagasse, sucrose, and soybean flour) on GH biosynthesis was assessed using experimental mixture design (EMD). Additionally, the effect of increased component concentrations in culture media selected from the EMD was studied. It was found that that a mixed culture medium could significantly maximize GH biosynthesis rate, especially for xylanase enzymes which achieved a 2-fold increment. Overall, it was demonstrated that T. harzianumP49P11 enzymes have a great potential to be used in the deconstruction of biomass.

  9. Bioreactors addressing diabetes mellitus.

    Science.gov (United States)

    Minteer, Danielle M; Gerlach, Jorg C; Marra, Kacey G

    2014-11-01

    The concept of bioreactors in biochemical engineering is a well-established process; however, the idea of applying bioreactor technology to biomedical and tissue engineering issues is relatively novel and has been rapidly accepted as a culture model. Tissue engineers have developed and adapted various types of bioreactors in which to culture many different cell types and therapies addressing several diseases, including diabetes mellitus types 1 and 2. With a rising world of bioreactor development and an ever increasing diagnosis rate of diabetes, this review aims to highlight bioreactor history and emerging bioreactor technologies used for diabetes-related cell culture and therapies.

  10. Oscillating Cell Culture Bioreactor

    Science.gov (United States)

    Freed, Lisa E.; Cheng, Mingyu; Moretti, Matteo G.

    2010-01-01

    To better exploit the principles of gas transport and mass transport during the processes of cell seeding of 3D scaffolds and in vitro culture of 3D tissue engineered constructs, the oscillatory cell culture bioreactor provides a flow of cell suspensions and culture media directly through a porous 3D scaffold (during cell seeding) and a 3D construct (during subsequent cultivation) within a highly gas-permeable closed-loop tube. This design is simple, modular, and flexible, and its component parts are easy to assemble and operate, and are inexpensive. Chamber volume can be very low, but can be easily scaled up. This innovation is well suited to work with different biological specimens, particularly with cells having high oxygen requirements and/or shear sensitivity, and different scaffold structures and dimensions. The closed-loop changer is highly gas permeable to allow efficient gas exchange during the cell seeding/culturing process. A porous scaffold, which may be seeded with cells, is fixed by means of a scaffold holder to the chamber wall with scaffold/construct orientation with respect to the chamber determined by the geometry of the scaffold holder. A fluid, with/without biological specimens, is added to the chamber such that all, or most, of the air is displaced (i.e., with or without an enclosed air bubble). Motion is applied to the chamber within a controlled environment (e.g., oscillatory motion within a humidified 37 C incubator). Movement of the chamber induces relative motion of the scaffold/construct with respect to the fluid. In case the fluid is a cell suspension, cells will come into contact with the scaffold and eventually adhere to it. Alternatively, cells can be seeded on scaffolds by gel entrapment prior to bioreactor cultivation. Subsequently, the oscillatory cell culture bioreactor will provide efficient gas exchange (i.e., of oxygen and carbon dioxide, as required for viability of metabolically active cells) and controlled levels of fluid

  11. Landfilling: Environmental Issues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Manfredi, Simone; Kjeldsen, Peter

    2011-01-01

    Waste disposed of in a landfill is by its nature different from the material found in the surroundings of the landfill and thereby the landfill may potentially affect the surrounding environment. This may be in terms of attracting or repelling flora and fauna from the area and through the emissio...

  12. Perfusion Bioreactor Module

    Science.gov (United States)

    Morrison, Dennis R.

    1990-01-01

    Perfusion bioreactor module, self-contained, closed-loop cell-culture system that operates in microgravity or on Earth. Equipment supports growth or long-term maintenance of cultures of human or other fragile cells for experiments in basic cell biology or process technology. Designed to support proliferation (initially at exponential rates of growth) of cells in complex growth medium and to maintain confluent cells in defined medium under conditions optimized to permit or encourage selected functions of cells, including secretion of products of cells into medium.

  13. 厌氧-准好氧联合型生物反应器填埋场渗滤液水质水量变化规律的研究%Evolution of Leachate Quantity and Quality in the Anaerobic-semiaerobic Bioreactor Landfill

    Institute of Scientific and Technical Information of China (English)

    韩智勇; 刘丹; 李启彬; 陈馨

    2012-01-01

    The Anaerobic-semiaerobic Bioreactor Landfill(AN-SABL) has been devised combining an Anaerobic Bioreactor Landfill(ANBL) with a Semi-aerobic Aged Refuse Biofilter(SAARB) for reducing the investment and the running expense.It was a novel bioreactor landfill which could accelerate the stabilization of waste obviously.The evolution of leachate quantity and quality for the AN-SABL was studied in order to provide a theoretical basis for the management and treatment of leachate.The results indicated that the quantitative reduction of leachate in the AN-SABL was obvious and the highest reduction could reach by 771 g·kg-1.Moreover,the quality of leachate varied in phases.The concentration of nitrate including nitrite and ammonium was influenced markedly by Eh and pH.At the end of the experiment,the removal rates of COD for the AN-SABL2 and the AN-SABL3 reached by 98.49% and 97.98% and the concentrations of COD were only 14.5% and 21.1% of that in leachate from the ANBL1 respectively.Therefore,the organic matter could be degraded completely with the AN-SABL.Besides,the AN-SABL could remove the nitrogen pollutant effectively as well.The concentrations of ammonium in leachate from the AN-SABL2 and the AN-SABL3 decreased obviously from the maximum of 1 452 mg·L^-1 and 1 409 mg·L^-1 to 525 mg·L^-1 and 459 mg·L^-1 respectively which only were 36.5% and 31.9% of that in leachate from the ANBL1.For the SAARB unit,the TOC and TC ratio played a vital influence on the removal efficiency of the organic matter and nitrogen pollutant.After the TOC and TC ratio declined to about 0.2,the removal rate of COD and TN for SAARB decreased from over 95% and over 93% to 35.25%-69.56% and 64.53%-77.45% respectively.%为了减少生物反应器填埋场投资和运行费用,实现填埋场的快速稳定化,将厌氧型生物反应器填埋场(ANBL)和准好氧矿化垃圾生物反应床(SAARB)串联,组成新型的厌氧-准好氧联合型生物反应器填埋场(AN-SABL).通过

  14. Research, development and demonstration in the design of sanitary landfill to optimize the generation and capture of compressible gas

    Science.gov (United States)

    Nosanov, M. E.; Teeple, F. E.; Buesch, S. C.

    1982-02-01

    The influences of selected factors on the generation and recovery of methane gas from sanitary landfills were investigated. The factors included encapsulation, shredding, air classifying, moisture, and pH. Facilities consisting of six model sanitary landfill cells, each with a capacity of approximately 450 cubic yards of municipal waste, and auxiliary subsystems were constructed. Municipal waste in each cell is contained in a 30-mil thick polyvinly chloride plastic sheeting forming a virtually gas-tight envelope. Two cells were filled with as-collected urban waste, two with shredded waste, and two with shredded and air classified waste, constituting three pairs of cells. One of each pair is a control cell with the other used as an experimental variable. Systems were provided for adding measured amounts of water, removing and recirculating leachate, and for extracting gas and measuring gas flow. During testing, gas production and internal cell characteristics were measured to determine the effects of mechanical processing, moisture content, and leachate pH.

  15. Design and validation of a novel bioreactor principle to combine online micro-computed tomography monitoring and mechanical loading in bone tissue engineering

    Science.gov (United States)

    Hagenmüller, Henri; Hitz, Marco; Merkle, Hans P.; Meinel, Lorenz; Müller, Ralph

    2010-01-01

    Mechanical loading plays an important role in bone remodeling in vivo and, therefore, has been suggested as a key parameter in stem cell-based engineering of bone-like tissue in vitro. However, the optimization of loading protocols during stem cell differentiation and subsequent bone-like tissue formation is challenged by multiple input factors, which are difficult to control and validate. These include the variable cellular performance of cells harvested from different patients, nonstandardized culture media components, the choice of the biomaterial forming the scaffold, and its morphology, impacting a broader validity of mechanical stimulation regimens. To standardize the cell culture of bone-like tissue constructs, we suggest the involvement of time-lapsed feedback loops. For this purpose we present a prototype bioreactor that combines online, nondestructive monitoring using micro-computed tomography and direct mechanical loading of three-dimensional tissue engineering constructs. Validation of this system showed displacement steps down to 1 μm and cyclic sinusoidal loadings of up to 10 Hz. Load detection resolution was 0.01 N, and micro-computed tomography data were of high quality. For the first time, the developed bioreactor links time-lapsed, nondestructive, and dynamic imaging with mechanical stimulation, designed for cell culture under sterile conditions. This system is believed to substantially improve today's experimental options to study and optimize osteogenic stem cell culture and differentiation at the interface with mechanical stimulation.

  16. Design and validation of a novel bioreactor principle to combine online micro-computed tomography monitoring and mechanical loading in bone tissue engineering.

    Science.gov (United States)

    Hagenmüller, Henri; Hitz, Marco; Merkle, Hans P; Meinel, Lorenz; Müller, Ralph

    2010-01-01

    Mechanical loading plays an important role in bone remodeling in vivo and, therefore, has been suggested as a key parameter in stem cell-based engineering of bone-like tissue in vitro. However, the optimization of loading protocols during stem cell differentiation and subsequent bone-like tissue formation is challenged by multiple input factors, which are difficult to control and validate. These include the variable cellular performance of cells harvested from different patients, nonstandardized culture media components, the choice of the biomaterial forming the scaffold, and its morphology, impacting a broader validity of mechanical stimulation regimens. To standardize the cell culture of bone-like tissue constructs, we suggest the involvement of time-lapsed feedback loops. For this purpose we present a prototype bioreactor that combines online, nondestructive monitoring using micro-computed tomography and direct mechanical loading of three-dimensional tissue engineering constructs. Validation of this system showed displacement steps down to 1 microm and cyclic sinusoidal loadings of up to 10 Hz. Load detection resolution was 0.01 N, and micro-computed tomography data were of high quality. For the first time, the developed bioreactor links time-lapsed, nondestructive, and dynamic imaging with mechanical stimulation, designed for cell culture under sterile conditions. This system is believed to substantially improve today's experimental options to study and optimize osteogenic stem cell culture and differentiation at the interface with mechanical stimulation.

  17. H{sub 2} production from marine and freshwater species of green algae during sulfur deprivation and considerations for bioreactor design

    Energy Technology Data Exchange (ETDEWEB)

    Skjaanes, Kari [Department of Biology, University of Bergen (UiB), Box 7800, N-5020 Bergen (Norway); Department of Photochemistry and Molecular Science, The Aangstroem Laboratories, Uppsala University, Box 523, SE-751 20 Uppsala (Sweden); Knutsen, Gjert [Department of Biology, University of Bergen (UiB), Box 7800, N-5020 Bergen (Norway); Kaellqvist, Torsten [Norwegian Institute for Water Research (NIVA), Gaustadaleen 21, N-0349 Oslo (Norway); Lindblad, Peter [Department of Photochemistry and Molecular Science, The Aangstroem Laboratories, Uppsala University, Box 523, SE-751 20 Uppsala (Sweden)

    2008-01-15

    Twenty-one species of green algae isolated from marine, freshwater and terrestrial environments were screened for the ability to produce H{sub 2} under anaerobic conditions. Seven strains found positive for H{sub 2} production under anaerobic conditions were also screened for the ability to produce H{sub 2} under sulfur (S) deprivation. In addition to the traditional model species Chlamydomonas reinhardtii, C. noctigama (freshwater) and C. euryale (brackish water) were able to produce significant amounts of H{sub 2} under S-deprivation. These species were also able to utilize acetate as a substrate for growth in light. The S-deprivation experiments were performed under photoheterotrophic conditions in a purpose-specific designed bioreactor, and it was shown that an automated pH adjustment feature was essential to maintain a stable pH in the cultures. Several materials commonly used in bioreactors, such as rubber materials, plastics and steel alloys, had a negative effect on the survival of S-deprived algae cultures. Unexpectedly, traces of H{sub 2} were produced under S-deprivation during O{sub 2} saturation in the cultures, possibly derived from local anaerobic environments formed in algal biofilms on the membranes covering the O{sub 2} electrodes. (author)

  18. Microbes in biological processes for municipal landfill leachate treatment: Community, function and interaction

    DEFF Research Database (Denmark)

    Zhang, Duoying; Vahala, Riku; Wang, Yu

    2016-01-01

    Landfill leachate (LFL) contains high strength of ammonium and complex organic substances including biodegradable volatile fatty acids (VFAs), refractory aquatic humic substances (AHS) and micro-scale xenobiotic organic chemicals (XOCs), which promotes the diverse microbial community in LFL...... treatment bioreactors. These microbes cooperate to remove nitrogen, biodegrade organic matters, eliminate the toxicity of XOCs and produce energy. In these diverse microbes, some show dominant in the bioreactor and are prevalent in many kinds of LFL treatment bio-processes, such as Brocadia from the phylum....... High ammonium loading, low DO (bacteria (AnAOB). In anaerobic LFL treatment bioreactors, Methanosaeta...

  19. A Student Team in a University of Michigan Biomedical Engineering Design Course Constructs a Microfluidic Bioreactor for Studies of Zebrafish Development

    Science.gov (United States)

    Shen, Yu-chi; Li, David; Al-Shoaibi, Ali; Bersano-Begey, Tom; Chen, Hao; Ali, Shahid; Flak, Betsy; Perrin, Catherine; Winslow, Max; Shah, Harsh; Ramamurthy, Poornapriya; Schmedlen, Rachael H.; Takayama, Shuichi

    2009-01-01

    Abstract The zebrafish is a valuable model for teaching developmental, molecular, and cell biology; aquatic sciences; comparative anatomy; physiology; and genetics. Here we demonstrate that zebrafish provide an excellent model system to teach engineering principles. A seven-member undergraduate team in a biomedical engineering class designed, built, and tested a zebrafish microfluidic bioreactor applying microfluidics, an emerging engineering technology, to study zebrafish development. During the semester, students learned engineering and biology experimental design, chip microfabrication, mathematical modeling, zebrafish husbandry, principles of developmental biology, fluid dynamics, microscopy, and basic molecular biology theory and techniques. The team worked to maximize each person's contribution and presented weekly written and oral reports. Two postdoctoral fellows, a graduate student, and three faculty instructors coordinated and directed the team in an optimal blending of engineering, molecular, and developmental biology skill sets. The students presented two posters, including one at the Zebrafish meetings in Madison, Wisconsin (June 2008). PMID:19292670

  20. Cell Separations in Microgravity and Development of a Space Bioreactor

    Science.gov (United States)

    Morrison, D. R.

    1985-01-01

    A bioreactor optimized for operations in space is now being developed. The current research is focused on determining the optimum cell-bead ratios, medium content and proper maintenance conditions required to keep living cell specimens alive and healthy for the entire flight. The bioreactor development project has recently added a microprocessor/computer to the JSC prototype for control and data analysis. Appropriate new technology is being combined with the current bioreactor designs and tested to determine what specific features must be included in the fabrication of a bioreactor designed to operate for STS demonstration tests. Considerations include: (1) circulation and resupply of culture media; (2) sensors required to monitor temperature, cell growth, mass transport, and oxygen consumption; and (3) inflight control of shear stress on cells, gas transfer in microgravity, diffusion, and intracellular transport. These data and results from the JSC prototype bioreactor test will be used for the design and construction of a small space bioreactor for the Orbiter middeck.

  1. Tissue grown in space in NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    For 5 days on the STS-70 mission, a bioreactor cultivated human colon cancer cells, such as the culture section shown here, which grew to 30 times the volume of control specimens grown on Earth. This significant result was reproduced on STS-85 which grew mature structures that more closely match what are found in tumors in humans. The two white circles within the tumor are part of a plastic lattice that helped the cells associate. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators.

  2. Case study: City of Industry landfill gas recovery operation

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-11-01

    Development of civic, recreation, and conservation facilities throughout a 150-acre site which had been used for waste disposal from 1951 to 1970 is described. The history of the landfill site, the geology of the site, and a test well program to assess the feasibility of recoverying landfill gas economically from the site are discussed. Based on results of the test well program, the City of Industry authorized the design and installation of a full-scale landfill gas recovery system. Design, construction, and operation of the system are described. The landfill gas system provides fuel for use in boilers to meet space heating and hot water demands for site development (MCW)

  3. Operating a fuel cell using landfill gas

    Energy Technology Data Exchange (ETDEWEB)

    Trippel, C.E.; Preston, J.L. Jr.; Trocciola, J.; Spiegel, R.

    1996-12-31

    An ONSI PC25{trademark}, 200 kW (nominal capacity) phosphoric acid fuel cell operating on landfill gas is installed at the Town of Groton Flanders Road landfill in Groton, Connecticut. This joint project by the Connecticut Light & Power Company (CL&P) which is an operating company of Northeast Utilities, the Town of Groton, International Fuel Cells (IFC), and the US EPA is intended to demonstrate the viability of installing, operating and maintaining a fuel cell operating on landfill gas at a landfill site. The goals of the project are to evaluate the fuel cell and gas pretreatment unit operation, test modifications to simplify the GPU design and demonstrate reliability of the entire system.

  4. Nitrous oxides reduction pathways induced during nitrified leachate recirculation in bioreactor landfill; Voies de reduction des oxydes d'azote lors de leur injection dans un massif de dechets menagers et assimiles: contribution a l'etude de la recirculation de lixiviat nitrifie dans une installation de stockage de dechets menagers et assimiles bioactive

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, V.

    2005-12-15

    Nitrified leachate recirculation in bioreactor landfill has been proposed to avoid ammonium accumulation. We worked on the identification of nitrous oxides reduction pathways induced when nitrified leachate is recirculated during waste degradation. Batch reactors (1.1 liter, 40 g of reconstituted Municipal Solid Waste, MSW) were operated at 35 deg C and saturated with leachate. Injections of 250 mg N-NO{sub x}.10{sup -1} were performed during different phases of waste biodegradation. Nitrate reduction during acido-genic and active methanogenic phases, with an easily available carbon source in leachate, was mainly attributed to heterotrophic denitrification. However, H{sub 2}S concentration up to 0.7 % in the biogas (corresponding to 0.5 mmol of free H{sub 2}S per liter of leachate) led to prevalent DNRA (Dissimilatory Nitrate Reduction to Ammonium) over denitrification. This reaction hindered the release of nitrogen outside of the system. This observation was confirmed with experiments performed with {sup 15}N enriched nitrate. During late methanogenic phase, without any available carbon source in leachate, nitrate was reduced by autotrophic denitrification with sulfide as an electron donor. No free metal was detected in the leachate. N{sub 2}O transient accumulation was detected during both DNRA and autotrophic denitrification. A second set of experiments was conducted in a MSW pilot scale column (0.2 m{sup 3}, 80 kg of reconstituted waste) in methanogenic phase. 113 % and 203 % of nitrate were converted into N{sub 2} when a synthetic KNO{sub 3} solution (280 mg N.day{sup -1} during 77 days) or nitrified leachate (61 mg N.day{sup -1} during 54 days) were respectively injected into the system. The downward movement of a denitrification front passing through the waste mass was followed using 3 redox probes inserted at different levels of the pilot. Even if N{sub 2}O was never detected, a small production of this gas could not be totally excluded. It was established

  5. Minimizing N2O fluxes from full-scale municipal solid waste landfill with properly selected cover soil

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Municipal solid waste landfills emit nitrous oxide (N2O) gas. Assuming that the soil cover is the primary N2O source from landfills,this study tested, during a four-year project, the hypothesis that the proper use of chosen soils with fine texture minimizes N2O emissions. A full-scale sanitary landfill, a full-scale bioreactor landfill and a cell planted with Nerium indicum or Festuca arundinacea Schreb, at the Hangzhou Tianziling landfill in Hangzhou City were the test sites. The N2O emission rates from all test sites were considerably lower than those reported in the published reports. Specifically, the N2O emission rate was dependent on soil water content and nitrate concentrations in the cover soil. The effects of leachate recirculation and irrigation were minimal. Properly chosen cover soils applied to the landfills reduced N2O flux.

  6. Design of photo-bioreactor and the application for cultivating algae%藻类光生物反应器的设计及应用研究

    Institute of Scientific and Technical Information of China (English)

    董汝晶; 谯顺彬; 田辉; 张义明; 罗芳; 陶希芹

    2012-01-01

    A new photo-bioreactor was designed basing on the growth trait of the algae.The volume of the reactor was 10.0L,the length,width and height was 320,80,390mm,respectively.Used the reactor to culture Spirulina platensis,and employed the response surface methodology to optimize the fermentation conditions.Then,researched the optimization concentration levels and the relations between these factors and building up a quadratic regression equation with dry weight as the dependent,light intensity,air flow,time of cultivation and volume of medium as independent.Under the optimistically conditions,the final dry weight was 1.298g/L.According to the experiment results,the photo-bioreactor designed was fit to cultivate the algae.%根据藻类的生长特点设计了一个容积为10.0L的光生物反应器,其长×宽×高分别为320mm×80mm×390mm。利用该反应器进行螺旋藻培养实验,采用响应面法对其培养条件进行优化研究,建立以藻体干重为响应值,以光照强度、通气量、培养时间和装液量为自变量的二次多项式数学模型。培养条件优化后螺旋藻最终干重为1.298g/L。实验结果表明,所设计的反应器能很好地满足藻类生长,其培养产率也明显提高。

  7. Factorial experimental design for the culture of human embryonic stem cells as aggregates in stirred suspension bioreactors reveals the potential for interaction effects between bioprocess parameters.

    Science.gov (United States)

    Hunt, Megan M; Meng, Guoliang; Rancourt, Derrick E; Gates, Ian D; Kallos, Michael S

    2014-01-01

    Traditional optimization of culture parameters for the large-scale culture of human embryonic stem cells (ESCs) as aggregates is carried out in a stepwise manner whereby the effect of varying each culture parameter is investigated individually. However, as evidenced by the wide range of published protocols and culture performance indicators (growth rates, pluripotency marker expression, etc.), there is a lack of systematic investigation into the true effect of varying culture parameters especially with respect to potential interactions between culture variables. Here we describe the design and execution of a two-parameter, three-level (3(2)) factorial experiment resulting in nine conditions that were run in duplicate 125-mL stirred suspension bioreactors. The two parameters investigated here were inoculation density and agitation rate, which are easily controlled, but currently, poorly characterized. Cell readouts analyzed included fold expansion, maximum density, and exponential growth rate. Our results reveal that the choice of best case culture parameters was dependent on which cell property was chosen as the primary output variable. Subsequent statistical analyses via two-way analysis of variance indicated significant interaction effects between inoculation density and agitation rate specifically in the case of exponential growth rates. Results indicate that stepwise optimization has the potential to miss out on the true optimal case. In addition, choosing an optimum condition for a culture output of interest from the factorial design yielded similar results when repeated with the same cell line indicating reproducibility. We finally validated that human ESCs remain pluripotent in suspension culture as aggregates under our optimal conditions and maintain their differentiation capabilities as well as a stable karyotype and strong expression levels of specific human ESC markers over several passages in suspension bioreactors.

  8. A performance-based method for calculating the design thickness of compacted clay liners exposed to high strength leachate under simulated landfill conditions.

    Science.gov (United States)

    Safari, Edwin; Jalili Ghazizade, Mahdi; Abdoli, Mohammad Ali

    2012-09-01

    Compacted clay liners (CCLs) when feasible, are preferred to composite geosynthetic liners. The thickness of CCLs is typically prescribed by each country's environmental protection regulations. However, considering the fact that construction of CCLs represents a significant portion of overall landfill construction costs; a performance based design of liner thickness would be preferable to 'one size fits all' prescriptive standards. In this study researchers analyzed the hydraulic behaviour of a compacted clayey soil in three laboratory pilot scale columns exposed to high strength leachate under simulated landfill conditions. The temperature of the simulated CCL at the surface was maintained at 40 ± 2 °C and a vertical pressure of 250 kPa was applied to the soil through a gravel layer on top of the 50 cm thick CCL where high strength fresh leachate was circulated at heads of 15 and 30 cm simulating the flow over the CCL. Inverse modelling using HYDRUS-1D indicated that the hydraulic conductivity after 180 days was decreased about three orders of magnitude in comparison with the values measured prior to the experiment. A number of scenarios of different leachate heads and persistence time were considered and saturation depth of the CCL was predicted through modelling. Under a typical leachate head of 30 cm, the saturation depth was predicted to be less than 60 cm for a persistence time of 3 years. This approach can be generalized to estimate an effective thickness of a CCL instead of using prescribed values, which may be conservatively overdesigned and thus unduly costly.

  9. Significance of membrane bioreactor design on the biocatalytic performance of glucose oxidase and catalase: Free vs. immobilized enzyme systems

    DEFF Research Database (Denmark)

    Morthensen, Sofie Thage; Meyer, Anne S.; Jørgensen, Henning

    2017-01-01

    -induced enzyme immobilization in the porous support of an ultrafiltration membrane was used as strategy for entrapment of glucose oxidase and catalase. The biocatalytic productivity of the membrane reactor was found to be highly related to the oxygen availability, which in turn depended on the reactor......Membrane separation of xylose and glucose can be accomplished via oxidation of glucose to gluconic acid by enzymatic glucose oxidase catalysis. Oxygen for this reaction can be supplied via decomposition of hydrogen peroxide by enzymatic catalase catalysis. In order to maximize the biocatalytic...... productivity of glucose oxidase and catalase (gluconic acid yield per total amount of enzyme) the following system set-ups were compared: immobilization of glucose oxidase alone; co-immobilization of glucose oxidase and catalase; glucose oxidase and catalase free in the membrane bioreactor. Fouling...

  10. Design criteria for semi-central sanitation with low pressure network and membrane bioreactor-the ENREM project.

    Science.gov (United States)

    Gnirss, Regina; Luedicke, Carsten; Vocks, Martin; Lesjean, Boris

    2008-01-01

    MBR-technology is able to fulfil similar or even higher standard for nutrients removal than conventional activated sludge processes. This paper presents the optimisation of the membrane bioreactor technology, together with a low pressure sewer, to equip a remote and yet unsewered area of Berlin requiring high quality wastewater treatment. The hydraulic flow pattern of the entire system has to be studied carefully due to the small collection system (no time delay between wastewater discharge and treatment to minimise the daily profile). The pollutant concentrations in the wastewater exhibit also stronger variations. In order to flatten out the hydraulic and load profile, and therefore to reduce the size of the biological reactor and the membrane surface, a buffer tank was installed before the MBR-plant. A full analysis of the influent hydraulic flow and wastewater characterisation is provided for the demonstration MBR-plant.

  11. Production of oncolytic adenovirus and human mesenchymal stem cells in a single-use, Vertical-Wheel bioreactor system: Impact of bioreactor design on performance of microcarrier-based cell culture processes.

    Science.gov (United States)

    Sousa, Marcos F Q; Silva, Marta M; Giroux, Daniel; Hashimura, Yas; Wesselschmidt, Robin; Lee, Brian; Roldão, António; Carrondo, Manuel J T; Alves, Paula M; Serra, Margarida

    2015-01-01

    Anchorage-dependent cell cultures are used for the production of viruses, viral vectors, and vaccines, as well as for various cell therapies and tissue engineering applications. Most of these applications currently rely on planar technologies for the generation of biological products. However, as new cell therapy product candidates move from clinical trials towards potential commercialization, planar platforms have proven to be inadequate to meet large-scale manufacturing demand. Therefore, a new scalable platform for culturing anchorage-dependent cells at high cell volumetric concentrations is urgently needed. One promising solution is to grow cells on microcarriers suspended in single-use bioreactors. Toward this goal, a novel bioreactor system utilizing an innovative Vertical-Wheel™ technology was evaluated for its potential to support scalable cell culture process development. Two anchorage-dependent human cell types were used: human lung carcinoma cells (A549 cell line) and human bone marrow-derived mesenchymal stem cells (hMSC). Key hydrodynamic parameters such as power input, mixing time, Kolmogorov length scale, and shear stress were estimated. The performance of Vertical-Wheel bioreactors (PBS-VW) was then evaluated for A549 cell growth and oncolytic adenovirus type 5 production as well as for hMSC expansion. Regarding the first cell model, higher cell growth and number of infectious viruses per cell were achieved when compared with stirred tank (ST) bioreactors. For the hMSC model, although higher percentages of proliferative cells could be reached in the PBS-VW compared with ST bioreactors, no significant differences in the cell volumetric concentration and expansion factor were observed. Noteworthy, the hMSC population generated in the PBS-VW showed a significantly lower percentage of apoptotic cells as well as reduced levels of HLA-DR positive cells. Overall, these results showed that process transfer from ST bioreactor to PBS-VW, and scale-up was

  12. Review of nonconventional bioreactor technology

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C.E.; Mcllwain, M.E.

    1993-09-01

    Biotechnology will significantly affect many industrial sectors in the future. Industrial sectors that will be affected include pharmaceutical, chemical, fuel, agricultural, and environmental remediation. Future research is needed to improve bioprocessing efficiency and cost-effectiveness in order to compete with traditional technologies. This report describes recent advances in bioprocess technologies and bioreactor designs and relates them to problems encountered in many industrial bioprocessing operations. The primary focus is directed towards increasing gas and vapor transfer for enhanced bioprocess kinetics as well as unproved by-product separation and removal. The advantages and disadvantages of various conceptual designs such as hollow-fiber, gas-phase, hyperbaric/hypobaric, and electrochemical bioreactors are also discussed. Specific applications that are intended for improved bioprocesses include coal desulfurization, coal liquefaction, soil bioremediation, biomass conversion to marketable chemicals, biomining, and biohydrometallurgy as well as bioprocessing of gases and vapors.

  13. Landfill mining: Developing a comprehensive assessment method.

    Science.gov (United States)

    Hermann, Robert; Wolfsberger, Tanja; Pomberger, Roland; Sarc, Renato

    2016-11-01

    In Austria, the first basic technological and economic examinations of mass-waste landfills with the purpose to recover secondary raw materials have been carried out by the 'LAMIS - Landfill Mining Österreich' pilot project. A main focus of its research, and the subject of this article, is the first conceptual design of a comprehensive assessment method for landfill mining plans, including not only monetary factors (like costs and proceeds) but also non-monetary ones, such as the concerns of adjoining owners or the environmental impact. Detailed reviews of references, the identification of influences and system boundaries to be included in planning landfill mining, several expert workshops and talks with landfill operators have been performed followed by a division of the whole assessment method into preliminary and main assessment. Preliminary assessment is carried out with a questionnaire to rate juridical feasibility, the risk and the expenditure of a landfill mining project. The results of this questionnaire are compiled in a portfolio chart that is used to recommend, or not, further assessment. If a detailed main assessment is recommended, defined economic criteria are rated by net present value calculations, while ecological and socio-economic criteria are examined in a utility analysis and then transferred into a utility-net present value chart. If this chart does not support making a definite statement on the feasibility of the project, the results must be further examined in a cost-effectiveness analysis. Here, the benefit of the particular landfill mining project per capital unit (utility-net present value ratio) is determined to make a final distinct statement on the general benefit of a landfill mining project.

  14. Hollow fiber bioreactor technology for tissue engineering applications.

    Science.gov (United States)

    Eghbali, Hadis; Nava, Michele M; Mohebbi-Kalhori, Davod; Raimondi, Manuela T

    2016-01-01

    Hollow fiber bioreactors are the focus of scientific research aiming to mimic physiological vascular networks and engineer organs and tissues in vitro. The reason for this lies in the interesting features of this bioreactor type, including excellent mass transport properties. Indeed, hollow fiber bioreactors allow limitations to be overcome in nutrient transport by diffusion, which is often an obstacle to engineer sizable constructs in vitro. This work reviews the existing literature relevant to hollow fiber bioreactors in organ and tissue engineering applications. To this purpose, we first classify the hollow fiber bioreactors into 2 categories: cylindrical and rectangular. For each category, we summarize their main applications both at the tissue and at the organ level, focusing on experimental models and computational studies as predictive tools for designing innovative, dynamic culture systems. Finally, we discuss future perspectives on hollow fiber bioreactors as in vitro models for tissue and organ engineering applications.

  15. Heart tissue grown in NASA Bioreactor

    Science.gov (United States)

    2001-01-01

    Lisa Freed and Gordana Vunjak-Novakovic, both of the Massachusetts Institute of Technology (MIT), have taken the first steps toward engineering heart muscle tissue that could one day be used to patch damaged human hearts. Cells isolated from very young animals are attached to a three-dimensional polymer scaffold, then placed in a NASA bioreactor. The cells do not divide, but after about a week start to cornect to form a functional piece of tissue. Functionally connected heart cells that are capable of transmitting electrical signals are the goal for Freed and Vunjak-Novakovic. Electrophysiological recordings of engineered tissue show spontaneous contractions at a rate of 70 beats per minute (a), and paced contractions at rates of 80, 150, and 200 beats per minute respectively (b, c, and d). The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. The Bioreactor is rotated to provide gentle mixing of fresh and spent nutrient without inducing shear forces that would damage the cells. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). Credit: NASA and MIT.

  16. Colon tumor cells grown in NASA Bioreactor

    Science.gov (United States)

    2001-01-01

    These photos compare the results of colon carcinoma cells grown in a NASA Bioreactor flown on the STS-70 Space Shuttle in 1995 flight and ground control experiments. The cells grown in microgravity (left) have aggregated to form masses that are larger and more similar to tissue found in the body than the cells cultured on the ground (right). The principal investigator is Milburn Jessup of the University of Texas M. D. Anderson Cancer Center. The NASA Bioreactor provides a low turbulence culture environment which promotes the formation of large, three-dimensional cell clusters. Due to their high level of cellular organization and specialization, samples constructed in the bioreactor more closely resemble the original tumor or tissue found in the body. NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Cell constructs grown in a rotating bioreactor on Earth (left) eventually become too large to stay suspended in the nutrient media. In the microgravity of orbit, the cells stay suspended. Rotation then is needed for gentle stirring to replenish the media around the cells. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). Credit: NASA and University of Texas M. D. Anderson Cancer Center.

  17. Mitigation of methane emissions in a pilot-scale biocover system at the AV Miljø Landfill, Denmark: 1. System design and gas distribution

    DEFF Research Database (Denmark)

    Cassini, Filippo; Scheutz, Charlotte; Skov, Bent Henning

    2017-01-01

    Greenhouse gas mitigation at landfills by methane oxidation in engineered biocover systems is believed to be a cost effective technology, but so far a full quantitative evaluation of the efficiency of the technology in full scale has only been carried out in a few cases. A third generation semi......-passive biocover system was constructed at the AV Miljø Landfill, Denmark. The biocover system was fed by landfill gas pumped out of three leachate collection wells. An innovative gas distribution system was used to overcome the commonly observed surface emission hot spot areas resulting from an uGreenhouse gas...... mitigation at landfills by methane oxidation in engineered biocover systems is believed to be a cost effective technology, but so far a full quantitative evaluation of the efficiency of the technology in full scale has only been carried out in a few cases. A third generation semi-passive biocover system...

  18. Design of Rainwater and Sewage Separation System at Valley-type Landfill Site%山谷型生活垃圾填埋场库区雨污分流设计

    Institute of Scientific and Technical Information of China (English)

    苟剑锋; 曾正中; 徐燕; 郭浩磊

    2012-01-01

    以甘肃省肃南县城区生活垃圾填埋场为例,对山谷型生活垃圾填埋场库区的雨污分流措施进行了探讨,提出了一种填埋场雨污分流设计方案,以实现渗滤液的减量化,为山谷型生活垃圾填埋场工程的雨污分流设计提供了借鉴.%The rainwater and sewage separation measures at the valley-type municipal solid waste landfill site in Sunan County, Gansu Province are discussed. A design scheme for rainwater and sewage separation is proposed to achieve the reduction of leachate, which provides reference for design of the rainwater and sewage separation system at the valley-type municipal solid waste landfill site.

  19. Bio-tarp alternative daily cover prototypes for methane oxidation atop open landfill cells.

    Science.gov (United States)

    Adams, Bryn L; Besnard, Fabien; Bogner, Jean; Hilger, Helene

    2011-05-01

    Final landfill covers are highly engineered to prevent methane release into the atmosphere. However, methane production begins soon after waste placement and is an unaddressed source of emissions. The methane oxidation capacity of methanotrophs embedded in a "bio-tarp" was investigated as a means to mitigate methane release from open landfill cells. The bio-tarp would also serve as an alternative daily cover during routine landfill operation. Evaluations of nine synthetic geotextiles identified two that would likely be suitable bio-tarp components. Pilot tarp prototypes were tested in continuous flow systems simulating landfill gas conditions. Multilayered bio-tarp prototypes consisting of alternating layers of the two geotextiles were found to remove 16% of the methane flowing through the bio-tarp. The addition of landfill cover soil, compost, or shale amendments to the bio-tarp increased the methane removal up to 32%. With evidence of methane removal in a laboratory bioreactor, prototypes were evaluated at a local landfill using flux chambers installed atop intermediate cover at a landfill. The multilayered bio-tarp and amended bio-tarp configurations were all found to decrease landfill methane flux; however, the performance efficacy of bio-tarps was not significantly different from controls without methanotrophs. Because highly variable methane fluxes at the field site likely confounded the test results, repeat field testing is recommended under more controlled flux conditions.

  20. Open source software to control Bioflo bioreactors.

    Directory of Open Access Journals (Sweden)

    David A Burdge

    Full Text Available Bioreactors are designed to support highly controlled environments for growth of tissues, cell cultures or microbial cultures. A variety of bioreactors are commercially available, often including sophisticated software to enhance the functionality of the bioreactor. However, experiments that the bioreactor hardware can support, but that were not envisioned during the software design cannot be performed without developing custom software. In addition, support for third party or custom designed auxiliary hardware is often sparse or absent. This work presents flexible open source freeware for the control of bioreactors of the Bioflo product family. The functionality of the software includes setpoint control, data logging, and protocol execution. Auxiliary hardware can be easily integrated and controlled through an integrated plugin interface without altering existing software. Simple experimental protocols can be entered as a CSV scripting file, and a Python-based protocol execution model is included for more demanding conditional experimental control. The software was designed to be a more flexible and free open source alternative to the commercially available solution. The source code and various auxiliary hardware plugins are publicly available for download from https://github.com/LibourelLab/BiofloSoftware. In addition to the source code, the software was compiled and packaged as a self-installing file for 32 and 64 bit windows operating systems. The compiled software will be able to control a Bioflo system, and will not require the installation of LabVIEW.

  1. Open source software to control Bioflo bioreactors.

    Science.gov (United States)

    Burdge, David A; Libourel, Igor G L

    2014-01-01

    Bioreactors are designed to support highly controlled environments for growth of tissues, cell cultures or microbial cultures. A variety of bioreactors are commercially available, often including sophisticated software to enhance the functionality of the bioreactor. However, experiments that the bioreactor hardware can support, but that were not envisioned during the software design cannot be performed without developing custom software. In addition, support for third party or custom designed auxiliary hardware is often sparse or absent. This work presents flexible open source freeware for the control of bioreactors of the Bioflo product family. The functionality of the software includes setpoint control, data logging, and protocol execution. Auxiliary hardware can be easily integrated and controlled through an integrated plugin interface without altering existing software. Simple experimental protocols can be entered as a CSV scripting file, and a Python-based protocol execution model is included for more demanding conditional experimental control. The software was designed to be a more flexible and free open source alternative to the commercially available solution. The source code and various auxiliary hardware plugins are publicly available for download from https://github.com/LibourelLab/BiofloSoftware. In addition to the source code, the software was compiled and packaged as a self-installing file for 32 and 64 bit windows operating systems. The compiled software will be able to control a Bioflo system, and will not require the installation of LabVIEW.

  2. Corrective Action Plan for Corrective Action Unit 424: Area 3 Landfill Complex, Tonopah Test Range, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel Nevada

    1998-08-31

    This corrective action plan provides the closure implementation methods for the Area 3 Landfill Complex, Corrective Action Unit (CAU) 424, located at the Tonopah Test Range. The Area 3 Landfill Complex consists of 8 landfill sites, each designated as a separate corrective action site.

  3. Sulfur formation and recovery in a thiosulfateoxidizing bioreactor

    NARCIS (Netherlands)

    Gonzalez-Sanchez, A.; Meulepas, R.J.W.; Revah, S.

    2008-01-01

    This work describes the design and Performance of a thiosulfate-oxidizing bioreactor that allowed high elemental sulfur production and recovery efficiency. The reactor system, referred to as a Supernatant-Recycling Settler Bioreactor (SRSB), consisted of a cylindrical upflow reactor and a separate

  4. Sulfur formation and recovery in a thiosulfateoxidizing bioreactor

    NARCIS (Netherlands)

    Gonzalez-Sanchez, A.; Meulepas, R.J.W.; Revah, S.

    2008-01-01

    This work describes the design and Performance of a thiosulfate-oxidizing bioreactor that allowed high elemental sulfur production and recovery efficiency. The reactor system, referred to as a Supernatant-Recycling Settler Bioreactor (SRSB), consisted of a cylindrical upflow reactor and a separate a

  5. Design of Ditching Device for Greenhouse Straw Bioreactor%温室秸秆生物反应堆开沟装置的设计

    Institute of Scientific and Technical Information of China (English)

    樊禹铭; 董向辉; 刘欣

    2012-01-01

    in view of the existent problems in promoting straw bioreactor technology, including manual ditching, high labor intensity in earthing, and inefficiency, a novel ditching device is designed suitable for operation in greenhouse. This article examines the overall structure and working principle of the machine and makes optimization on its major components. The test and application of the device shows that the designed machine is rational in structure, efficient in operation, and low in power consumption. Therefore it should be promoted as a supportive equipment for straw bioreaetor technology.%针对秸秆生物反应堆技术推广中存在的人工开沟、覆土环节劳动强度过大、生产率低的问题,设计开发出适合在温室内作业的新型开沟装置。阐述该装置的总体结构与工作原理,对其关键部件进行优化设计。通过试制与应用,证实该装置结构合理、作业质量好、动力消耗小,可作为秸秆生物反应堆技术的配套机具进行推广应用。

  6. Enhanced stabilisation of municipal solid waste in bioreactor landfills

    NARCIS (Netherlands)

    Valencia Vázquez, R.

    2008-01-01

    The increasing development and urbanization of the society has led to an increase per-capita production of municipal solid waste (MSW) materials. These MSW materials are of organic and inorganic nature that can be of rapidly, moderately and slowly biodegradable or inert characteristics. With regard

  7. Enhanced stabilisation of municipal solid waste in bioreactor landfills

    NARCIS (Netherlands)

    Valencia Vázquez, R.

    2008-01-01

    The increasing development and urbanization of the society has led to an increase per-capita production of municipal solid waste (MSW) materials. These MSW materials are of organic and inorganic nature that can be of rapidly, moderately and slowly biodegradable or inert characteristics. With regard

  8. Landfill to Learning Facility

    Science.gov (United States)

    Venner, Laura

    2008-05-01

    Engaging "K-to-Gray” audiences (children, families, and older adults) in scientific exploration and discovery is the main goal of the NJMC Center for Environmental and Scientific Education and the William D. McDowell Observatory located in Lyndhurst, NJ. Perched atop a closed and reclaimed municipal solid waste landfill, our new LEED - certified building (certification pending) and William D. McDowell observatory will bring hands-on scientific experiences to the 25,000 students and 3,000 adults that visit our site from the NY/NJ region each year. Our programs adhere to the New Jersey Core Curriculum Content Standards and are modified for accessibility for the underserved communities that visit us, specifically those individuals that have mobility, sensory, and/or cognitive ability differences. The programs are conducted in a classroom setting and are designed to nourish the individual's inquisitive nature and provide an opportunity to function as a scientist by, making observations, performing experiments and recording data. We have an $850,000, three year NSF grant that targets adults with disabilities and older adults with age related limitations in vision, hearing, cognition and/or mobility. From dip netting in the marsh to astronomical investigation of the cosmos, the MEC/CESE remains committed to reaching the largest audience possible and leaving them with a truly exceptional scientific experience that serves to educate and inspire.

  9. Hydrodynamics research of wastewater treatment bioreactors

    Institute of Scientific and Technical Information of China (English)

    REN Nan-qi; ZHANG Bing; ZHOU Xue-fei

    2009-01-01

    To optimize the design and improve the performance of wastewater treatment bioreactors, the review concerning the hydrodynamics explored by theoretical equations, process experiments, modeling of the hydrody-namics and flow field measurement is presented. Results of different kinds of experiments show that the hydro-dynamic characteristics can affect sludge characteristics, mass transfer and reactor performance significantly. A-long with the development of theoretical equations, turbulence models including large eddy simulation models and Reynolds-averaged Navier-Stokes (RANS) models are widely used at present. Standard and modified k-ε models are the most widely used eddy viscosity turbulence models for simulating flows in bioreactors. Numericalsimulation of hydrodynamics is proved to be efficient for optimizing design and operation. The development of measurement techniques with high accuracy and low intrusion enables the flow filed in the bioreactors to be transparent. Integration of both numerical simulation and experimental measurement can describe the hydrody-namics very well.

  10. Morphological studies on the culture of kidney epithelial cells in a fiber-in-fiber bioreactor design with hollow fiber membranes.

    Science.gov (United States)

    Fey-Lamprecht, F; Albrecht, W; Groth, T; Weigel, T; Gross, U

    2003-05-01

    A hollow fiber-in-fiber-based bioreactor system was tested for the applicability to host kidney epithelial cells as a model system for a bioartificial kidney. Hollow fibers were prepared from polyacrylonitrile (PAN), polysulfone-polyvinylpyrollidinone (PVP) blend (PSU) and poly(acrylonitrile-N-vinylpyrollidinone) copolymer P(AN-NVP). Hollow fibers with smaller and larger diameters were prepared so that the smaller fitted into the larger, with a distance of 50-100 microm in between. The following material combinations as outer and inner fiber were applied: PAN-PAN; PSU-PSU, PSU-P(AN-NVP). Madin-Darby kidney epithelial cells (MDCK) were seeded in the interfiber space and cultured for a period up to 14 days. Light, scanning, and transmission electron microscopy were used to follow the adhesion and growth of cells, and to characterize their morphology. As a result, we found that MDCK cells were able to grow in the interfiber space in mono- and multilayers without signs of systemic degeneration. Comparison of the different materials showed that PAN and P(AN-NVP) provided the best growth conditions, indicated by a tight attachment of cells on hollow fiber membrane, and subsequent proliferation and development of structural elements of normal epithelia, such as tight junctions and microvilli. In conclusion, the fiber-in-fiber design seems to be an interesting system for the construction of a bioartificial kidney. Copyright 2003 Wiley Periodicals, Inc.

  11. Tapered bed bioreactor

    Science.gov (United States)

    Scott, Charles D.; Hancher, Charles W.

    1977-01-01

    A vertically oriented conically shaped column is used as a fluidized bed bioreactor wherein biologically catalyzed reactions are conducted in a continuous manner. The column utilizes a packing material a support having attached thereto a biologically active catalytic material.

  12. Turkey Run Landfill Emissions Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — landfill emissions measurements for the Turkey run landfill in Georgia. This dataset is associated with the following publication: De la Cruz, F., R. Green, G....

  13. Effect of nano-ZnO on biogas generation from simulated landfills.

    Science.gov (United States)

    Temizel, İlknur; Emadian, S Mehdi; Di Addario, Martina; Onay, Turgut T; Demirel, Burak; Copty, Nadim K; Karanfil, Tanju

    2017-05-01

    Extensive use of nanomaterials in commercial consumer products and industrial applications eventually leads to their release to the waste streams and the environment. Nano-ZnO is one of the most widely-used nanomaterials (NMs) due to its unique properties. It is also known to impact biological processes adversely. In this study, the effect of nano-ZnO on biogas generation from sanitary landfills was investigated. Two conventional and two bioreactor landfills were operated using real MSW samples at mesophilic temperature (35°C) for a period of about 1year. 100mg nano-ZnO/kg of dry waste was added to the simulated landfill reactors. Daily gas production, gas composition and leachate Zn concentrations were regularly monitored. A model describing the fate of the nano-ZnO was also developed. The results obtained indicated that as much as 99% of the nano-ZnO was retained within the waste matrix for both reactor operation modes. Waste stabilization was faster in simulated landfill bioreactors with and without the addition of nano-ZnO. Moreover, the presence of the nano-ZnO within the waste led to a decrease in biogas production of about 15%, suggesting that the nano-ZnO might have some inhibitory effects on waste stabilization. This reduction can have potentially significant implications on waste stabilization and the use of biogas from landfills as a renewable energy source. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Monitoring transitory profiles of leachate humic substances in landfill aeration reactors in mesophilic and thermophilic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Huanhuan [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Yin, Ke; Ge, Liya; Giannis, Apostolos [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); Chuan, Valerie W.L. [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Wang, Jing-Yuan, E-mail: JYWANG@ntu.edu.sg [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore)

    2015-04-28

    Highlights: • Polymerization and condensation of humic substances (HS) were enhanced by aeration. • Carboxylic group was enriched in HS by aeration presenting improved hydrophilicity. • Mobility of humic acid, as a result was enhanced by aeration especially in young landfill. • Waste age plays an important role in leachate management during aeration. - Abstract: The presence of humic substances (HS) in landfill leachate is of great interest because of their structural stability and potential toxicity. This study examined the effects of temperature and waste age on the transformation of HS during in situ aeration of bioreactor landfills. By establishing aerobic conditions, dissolved organic carbon (DOC) rapidly accumulated in the bioreactor leachate. Fractional analysis showed that the elevated concentration of humic acids (HAs) was primarily responsible for the increment of leachate strength. Further structural characterization indicated that the molecular weight (MW) and aromacity of HS were enhanced by aeration in conjunction with thermophilic temperature. Interestingly, elevation of HAs concentration was not observed in the aeration reactor with a prolonged waste age, as the mobility of HAs was lowered by the high MW derived from extended waste age. Based on these results, aeration may be more favorable in aged landfills, since dissolution of HAs could be minimized by the evolution to larger MW compared to young landfills. Moreover, increased operation temperature during aeration likely offers benefits for the rapid maturation of HS.

  15. Industrial Waste Landfill IV upgrade package

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-10-14

    This document consists of page replacements for the Y-12 industrial waste landfill. The cover page is to replace the old page, and a new set of text pages are to replace the old ones. A replacement design drawing is also included.

  16. The Measurement of Landfill Gas Emissions with the Orbiting Carbon Observatory and CarbonSAT Satellites

    Science.gov (United States)

    Vigil, S. A.; Bovensmann, H.

    2010-12-01

    Landfill gas is a significant contributor to anthropogenic emissions of CH4 and CO2. The U.S. Environmental Protection Agency has estimated the total U.S. 2007 emissions of the CH4 component of landfill gas at 132.9 Tg CO2 Equivalent. This compares to total CH4 emission from all US sources in 2007 at 585.3 Tg CO2 Equivalent. Worldwide CH4 emissions from landfill gas have been estimated at 668 Tg CO2 Equivalent. Satellite remote sensing can also be used to characterize landfill gas emissions. The NASA Orbiting Carbon Observatory (OCO-2) and the proposed CarbonSAT (University of Bremen) satellites are particularly suited for this purpose. The Orbiting Carbon Observatory (OCO) was designed to provided high spatial resolution ( developed countries. In general, landfills in the developed countries have landfill gas control system ground based landfill gas monitoring systems. These ground-based measurements can be used to calibrate OCO-2 and CarbonSAT landfill gas measurements. OCO-2 and CarbonSAT can be used to measure landfill emissions from the large landfills and open dumps of the emerging megacities in the developing world where accurate ground measurements are not available. For example Mexico City generates 26,000 MT of municipal solid waste that is disposed of in two uncontrolled landfills. Similar conditions exist in Asia, Latin America, and Africa. Satellite based measurements of these landfill gas emissions could help prioritize greenhouse gas remediation projects for these countries.

  17. Landfill Mining of Shredder Residues

    DEFF Research Database (Denmark)

    Hansen, Jette Bjerre; Hyks, Jiri; Shabeer Ahmed, Nassera

    In Denmark, shredder residues (SR) are classified as hazardous waste and until January 2012 the all SR were landfilled. It is estimated that more than 1.8 million tons of SR have been landfilled in mono cells. This paper describes investigations conducted at two Danish landfills. SR were excavated...

  18. Reduced-Gravity Experiments Conducted to Help Bioreactor Development

    Science.gov (United States)

    Niederhaus, Charles E.; Nahra, Henry K.; Kizito, John P.

    2004-01-01

    The NASA Glenn Research Center and the NASA Johnson Space Center are collaborating on fluid dynamic investigations for a future cell science bioreactor to fly on the International Space Station (ISS). Project Manager Steven Gonda from the Cellular Biotechnology Program at Johnson is leading the development of the Hydrodynamic Focusing Bioreactor--Space (HFB-S) for use on the ISS to study tissue growth in microgravity. Glenn is providing microgravity fluid physics expertise to help with the design and evaluation of the HFB-S. These bioreactors are used for three-dimensional tissue culture, which cannot be done in ground-based labs in normal gravity. The bioreactors provide a continual supply of oxygen for cell growth, as well as periodic replacement of cell culture media with nutrients. The bioreactor must provide a uniform distribution of oxygen and nutrients while minimizing the shear stresses on the tissue culture.

  19. Design of Cut-off Ditch at Valley-type Small Waste Sanitary Landfill Site in Southwest China%西南地区山谷型小型垃圾填埋场截洪沟设计

    Institute of Scientific and Technical Information of China (English)

    邹许鑫; 吕燕; 尹滔

    2012-01-01

    对西南地区山谷型小型垃圾填埋场截洪沟设计展开探讨,结合相关规范优选适用于西南地区的截洪沟设计充满度、设计流速、径流系数等关键设计参数,对截洪沟的流量计算、断面选择、沟壁沟底材料及基础设计、出水口及转弯段的设计、整体平面布置等进行讨论,提出三种优化截洪沟断面.通过截洪沟的优化设计可实现清污分流,降低渗滤液产量,减少雨水对垃圾渗滤液收集及处理系统的冲击,降低垃圾渗滤液处理成本,确保垃圾填埋场正常、安全运行.%The design of cut-off ditch at valley-type small landfill site in the southwest China is explored. The design parameters of cut-off ditch applicable to the southwest China, such as design filling degree, design flow, runoff coefficient and other key design parameters are selected according to the related codes. The flow calculation, cross section selection, materials and foundation design for the ditch walls and bottom, design of outlet and curved segment and overall layout are discussed. Three kinds of optimized cross sections of cut-off ditch are proposed. The optimization design of cut-off dilch can achieve the separation of rainwater and sewage, reduce the leachate production, mitigate the impact of rainwater on collection and treatment systems of landfill leachate, thus reducing the treatment cost of landfill leachate and ensuring the normal and safe operation of landfill site.

  20. Membrane Bioreactors design and operation improvements: The Spanish Experience; Avances en el diseno y la operacion de los biorreactores de membrana: La experiencia espanola

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias Esteban, R.; Ortega de Miguel, E.; Martinez Tarifa, M. A.; Simon Andreu, P.; Moragas Bouyart, L.; Garcia Fernandez, E.; Robuste Cartro, J.; Rodriguez-Roda layret, I.

    2012-07-01

    A Membrane Bioreactor (MBR) is a modification of a conventional activated sludge (CAS) plant where the secondary settling ins replaced by a low pressure ultrafiltration (UF) or micro filtration (MF) membranes separation process in order to obtain an effluent almost free of suspended solids and microorganisms. since the first MBR installation in 2002, the number and capacity of these systems have exponentially increased in spain, driven by the high quality of the effluent which allows direct reuse and discharge into environmentally sensitive areas, the compactness and automation of these plants and the possibility of upgrading existing wastewater treatment plants (WWTP) which no longer reach the required effluent quality levels. There were 45 operating MBR systems in 2011 and the total municipal wastewater treatment capacity by this type of plants will be about 90 hm{sup 3} in 204 when the current projects have been implemented. Today, Spain public and private wastewater management agencies consider MBR plants as an alternative of treatment but first they had to face a complex learning period to operate and design this kind of system. A significant progress has been made over the last years, but especially energy efficiency responds to the challenge of continuous improvement. Membrane fouling control consumes most of the energy involved in the process therefore, anti fouling materials and better membrane air-scour systems that allow the frequency and intensity of air flow to be controlled in realtime, are being investigated. This brings MBR closer to the CAS process in terms of energy efficiency. Breakthroughs in the design and operation of MBR plants are being collected in a guide for the implementation of MBR led by CEDEX, in which the main managers and operators are involved. This paper presents some of these improvements. (Author) 9 refs.

  1. LEACHATE CLOGGING ASSESSMENT OF GEOTEXTILE AND SOIL LANDFILL FILTERS

    Science.gov (United States)

    The liquids management strategy for any municipal or hazardous waste landfill requires a knowledgeable design strategy for the leachate collection system located at the base of the waste mass. Such leachate collection systems generally consist of sumps, perforated pipes, drainag...

  2. Mitigation of methane emissions in a pilot-scale biocover system at the av miljø landfill, denmark: system design and gas distribution

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Skov, B.; Cassini, Filippo

    2013-01-01

    Greenhouse gas mitigation at landfills by methane oxidation in engineered biocover systems is believed to be a cost effective technology but so far a full quantitative evaluation of the efficiency of the technology in full scale has only been carried out in a few cases. A third generation semi-pa...

  3. Astronomy on a Landfill

    Science.gov (United States)

    Venner, Laura

    2008-09-01

    Engaging "K-to-Gray” audiences (children, families, and older adults) in astronomical activities is one of the main goals of the NJMC Center for Environmental and Scientific Education and the William D. McDowell Observatory located in Lyndhurst, NJ. Perched atop a closed and reclaimed municipal solid waste landfill, our new LEED - certified building (certification pending) and William D. McDowell observatory will assist in bringing the goals of IYA 2009 to the approximately 25,000 students and 15,000 adults that visit our site from the NY/NJ region each year. Diversifying our traditional environmental science offerings, we have incorporated astronomy into our repertoire with "The Sun Through Time” module, which includes storytelling, cultural astronomy, telescope anatomy, and other activities that are based on the electromagnetic spectrum and our current knowledge of the sun. These lessons have also been modified to bring astronomy to underserved communities, specifically those individuals that have dexterity or cognitive ability differences. The program is conducted in a classroom setting and is designed to meet New Jersey Core Curriculum Content Standards. With the installation of our new 20” telescope, students and amateur astronomers will be given the opportunity to perform rudimentary research. In addition, a program is in development that will allow individuals to measure local sky brightness and understand the effects of light pollution on astronomical viewing. Teaching astronomy in an urban setting presents many challenges. All individuals, regardless of ability level or location, should be given the opportunity to be exposed to the wonders of the universe and the MEC/CESE has been successful in providing those opportunities.

  4. NASA Classroom Bioreactor

    Science.gov (United States)

    Scully, Robert

    2004-01-01

    Exploration of space provides a compelling need for cell-based research into the basic mechanisms that underlie the profound changes that occur in terrestrial life that is transitioned to low gravity environments. Toward that end, NASA developed a rotating bioreactor in which cells are cultured while continuously suspended in a cylinder in which the culture medium rotates with the cylinder. The randomization of the gravity vector accomplished by the continuous rotation, in a low shear environment, provides an analog of microgravity. Because cultures grown in bioreactors develop structures and functions that are much closer to those exhibited by native tissue than can be achieved with traditional culture methods, bioreactors have contributed substantially to advancing research in the fields of cancer, diabetes, infectious disease modeling for vaccine production, drug efficacy, and tissue engineering. NASA has developed a Classroom Bioreactor (CB) that is built from parts that are easily obtained and assembled, user-friendly and versatile. It can be easily used in simple school settings to examine the effect cultures of seeds or cells. An educational brief provides assembly instructions and lesson plans that describes activities in science, math and technology that explore free fall, microgravity, orbits, bioreactors, structure-function relationships and the scientific method.

  5. NASA Classroom Bioreactor

    Science.gov (United States)

    Scully, Robert

    2004-01-01

    Exploration of space provides a compelling need for cell-based research into the basic mechanisms that underlie the profound changes that occur in terrestrial life that is transitioned to low gravity environments. Toward that end, NASA developed a rotating bioreactor in which cells are cultured while continuously suspended in a cylinder in which the culture medium rotates with the cylinder. The randomization of the gravity vector accomplished by the continuous rotation, in a low shear environment, provides an analog of microgravity. Because cultures grown in bioreactors develop structures and functions that are much closer to those exhibited by native tissue than can be achieved with traditional culture methods, bioreactors have contributed substantially to advancing research in the fields of cancer, diabetes, infectious disease modeling for vaccine production, drug efficacy, and tissue engineering. NASA has developed a Classroom Bioreactor (CB) that is built from parts that are easily obtained and assembled, user-friendly and versatile. It can be easily used in simple school settings to examine the effect cultures of seeds or cells. An educational brief provides assembly instructions and lesson plans that describes activities in science, math and technology that explore free fall, microgravity, orbits, bioreactors, structure-function relationships and the scientific method.

  6. Environmental assessment of solid waste landfilling technologies by means of LCA-modeling.

    Science.gov (United States)

    Manfredi, Simone; Christensen, Thomas H

    2009-01-01

    By using life cycle assessment (LCA) modeling, this paper compares the environmental performance of six landfilling technologies (open dump, conventional landfill with flares, conventional landfill with energy recovery, standard bioreactor landfill, flushing bioreactor landfill and semi-aerobic landfill) and assesses the influence of the active operations practiced on these performances. The environmental assessments have been performed by means of the LCA-based tool EASEWASTE, whereby the functional unit utilized for the LCA is "landfilling of 1ton of wet household waste in a 10m deep landfill for 100 years". The assessment criteria include standard categories (global warming, nutrient enrichment, ozone depletion, photo-chemical ozone formation and acidification), toxicity-related categories (human toxicity and ecotoxicity) and impact on spoiled groundwater resources. Results demonstrate that it is crucially important to ensure the highest collection efficiency of landfill gas and leachate since a poor capture compromises the overall environmental performance. Once gas and leachate are collected and treated, the potential impacts in the standard environmental categories and on spoiled groundwater resources significantly decrease, although at the same time specific emissions from gas treatment lead to increased impact potentials in the toxicity-related categories. Gas utilization for energy recovery leads to saved emissions and avoided impact potentials in several environmental categories. Measures should be taken to prevent leachate infiltration to groundwater and it is essential to collect and treat the generated leachate. The bioreactor technologies recirculate the collected leachate to enhance the waste degradation process. This allows the gas collection period to be reduced from 40 to 15 years, although it does not lead to noticeable environmental benefits when considering a 100 years LCA-perspective. In order to more comprehensively understand the influence

  7. Human cell culture in a space bioreactor

    Science.gov (United States)

    Morrison, Dennis R.

    1988-01-01

    Microgravity offers new ways of handling fluids, gases, and growing mammalian cells in efficient suspension cultures. In 1976 bioreactor engineers designed a system using a cylindrical reactor vessel in which the cells and medium are slowly mixed. The reaction chamber is interchangeable and can be used for several types of cell cultures. NASA has methodically developed unique suspension type cell and recovery apparatus culture systems for bioprocess technology experiments and production of biological products in microgravity. The first Space Bioreactor was designed for microprocessor control, no gaseous headspace, circulation and resupply of culture medium, and slow mixing in very low shear regimes. Various ground based bioreactors are being used to test reactor vessel design, on-line sensors, effects of shear, nutrient supply, and waste removal from continuous culture of human cells attached to microcarriers. The small Bioreactor is being constructed for flight experiments in the Shuttle Middeck to verify systems operation under microgravity conditions and to measure the efficiencies of mass transport, gas transfer, oxygen consumption and control of low shear stress on cells.

  8. Methods of Sensing Land Pollution from Sanitary Landfills

    Science.gov (United States)

    Nosanov, Myron Ellis; Bowerman, Frank R.

    1971-01-01

    Major cities are congested and large sites suitable for landfill development are limited. Methane and other gases are produced at most sanitary landfills and dumps. These gases may migrate horizontally and vertically and have caused fatalities. Monitoring these gases provides data bases for design and construction of safe buildings on and adjacent to landfills. Methods of monitoring include: (1) a portable combustible gas indicator; and (2) glass flasks valved to allow simultaneous exhaust of the flask and aspiration of the sample into the flask. Samples are drawn through tubing from probes as deep as twenty-five feet below the surface.

  9. Indirect measurements of field-scale hydraulic conductivity of waste from two landfill sites.

    Science.gov (United States)

    Fleming, I R

    2011-12-01

    Management and prediction of the movement and distribution of fluids in large landfills is important for various reasons. Bioreactor landfill technology shows promise, but in arid or semi-arid regions, the natural content of landfilled waste may be low, thus requiring addition of significant volumes of water. In more humid locations, landfills can become saturated, flooding gas collection systems and causing sideslope leachate seeps or other undesirable occurrences. This paper compares results from two different approaches to monitoring water in waste. At the Brock West Landfill in eastern Canada, positive pore pressures were measured at various depths in saturated waste. The downward seepage flux through the waste is known, thus the vertical saturated hydraulic conductivity of the waste at this landfill was determined to be 3 × 10(-7)cm/s. By comparison, the Spadina Landfill in western Canada is predominantly unsaturated. The infiltration of moisture into the waste was measured using moisture sensors installed in boreholes which determined arrival time for moisture fronts resulting from major precipitation events as well as longer-term change in moisture content resulting from unsaturated drainage during winter when frozen ground prevented infiltration. The unsaturated hydraulic conductivity calculated from these data ranged from approximately 10(-6)cm/s for the slow winter drainage in the absence of significant recharge to 10(-2)cm/s or higher for shallow waste subject to high infiltration through apparent preferential pathways. These two very different approaches to field-scale measurements of vertical hydraulic conductivity provide insight into the nature of fluid movement in saturated and unsaturated waste masses. It is suggested that the principles of unsaturated seepage apply reasonably well for landfilled waste and that the hydraulic behavior of waste is profoundly influenced by the nature and size of voids and by the degree of saturation prevailing in the

  10. Cascades of bioreactors.

    NARCIS (Netherlands)

    Gooijer, de C.D.

    1995-01-01

    In this thesis a common phenomenon in bioprocess engineering is described : the execution of a certain bioprocess in more than one bioreactor. Chapter 1, a review, classifies bioprocesses by means of a number of characteristics :i) processes with a variable stoichiometry ,ii) processes with a consta

  11. Cascades of bioreactors

    NARCIS (Netherlands)

    Gooijer, de C.D.

    1995-01-01

    In this thesis a common phenomenon in bioprocess engineering is described : the execution of a certain bioprocess in more than one bioreactor. Chapter 1, a review, classifies bioprocesses by means of a number of characteristics :
    i) processes with a variable

  12. Yolo County controlled landfill project

    Energy Technology Data Exchange (ETDEWEB)

    Augenstein, D. [IEM, Palo Alto, CA (United States); Yazdani, R.; Dahl, K.; Mansoub, A.; Moore, R. [Yolo County Department of Public Works, Davis, CA (United States); Pacey, J. [Emcon, San Mateo, CA (United States)

    1999-07-01

    A new landfill management approach controlled landfilling is being demonstrated by the Yolo County, California Department of Public Works at the Yolo County Central Landfill (YCCL) near Davis. Overall objectives are to obtain earlier and greater methane energy recovery from landfilled waste and to reduce landfill greenhouse gas emissions to near-negligible levels. Methane generation and waste stabilization were accelerated by improving biological conditions within a test cell through carefully controlled additions of water and leachate. A control cell was operated in parallel. Landfill gas capture was maximized, with emissions reduced to minimal levels, by a combination of surface membrane containment, a permeable layer conducting gas to collection points, and operation at slight vacuum. Cells are highly instrumented to determine performance. To date, normalized methane recovery is the highest seen from such a large waste mass, anywhere - about ten times that from conventional landfall practice. The rationale and details of this project, and first three years' results, are summarized. (author)

  13. Disposable Bioreactors for Plant Micropropagation and Mass Plant Cell Culture

    Science.gov (United States)

    Ducos, Jean-Paul; Terrier, Bénédicte; Courtois, Didier

    Different types of bioreactors are used at Nestlé R&D Centre - Tours for mass propagation of selected plant varieties by somatic embryogenesis and for large scale culture of plants cells to produce metabolites or recombinant proteins. Recent studies have been directed to cut down the production costs of these two processes by developing disposable cell culture systems. Vegetative propagation of elite plant varieties is achieved through somatic embryogenesis in liquid medium. A pilot scale process has recently been set up for the industrial propagation of Coffea canephora (Robusta coffee). The current production capacity is 3.0 million embryos per year. The pre-germination of the embryos was previously conducted by temporary immersion in liquid medium in 10-L glass bioreactors. An improved process has been developed using a 10-L disposable bioreactor consisting of a bag containing a rigid plastic box ('Box-in-Bag' bioreactor), insuring, amongst other advantages, a higher light transmittance to the biomass due to its horizontal design. For large scale cell culture, two novel flexible plastic-based disposable bioreactors have been developed from 10 to 100 L working volumes, validated with several plant species ('Wave and Undertow' and 'Slug Bubble' bioreactors). The advantages and the limits of these new types of bioreactor are discussed, based mainly on our own experience on coffee somatic embryogenesis and mass cell culture of soya and tobacco.

  14. Determining design and scale-up parameters for degradation of atrazine with suspended Pseudomonas sp. ADP in aqueous bioreactors.

    Science.gov (United States)

    Biglione, Nicole; Rodgers, V G J; Peeples, Tonya L

    2008-01-01

    This work investigated the kinetic parameters of atrazine mineralization by suspended cells of Pseudomonas sp. ADP in both shake flasks and spherical stirred tank batch reactors (SSTR). The degradation of atrazine and growth of Pseudomonas sp. ADP were studied. Experiments were performed at different temperatures and stirring speeds in both reactors at varying initial concentrations of atrazine. Cell growth and atrazine concentration were monitored over time, and a Monod model with one limiting substrate was used to characterize the kinetic behavior. Temperature, stirring speed, and reactor type were all found to significantly affect the regressed Monod parameters. At 27 degrees C and 200 rpm, for the shaker flask experiments, mu max and Ks were determined to be 0.14 (+/-0.01) h-1 and 1.88 (+/-1.80) mg/L, respectively. At 37 degrees C, mu max and Ks increased to 0.25 (+/-0.05) h-1 and 9.59 (+/-6.55) mg/L, respectively. As expected, stirrer speed was also found to significantly alter the kinetic parameters. At 27 degrees C and 125 rpm, mu max and Ks were 0.04 (+/-0.002) h-1 and 3.72 (+/-1.05) mg/L, respectively, whereas at 37 degrees C and 125 rpm, mu max and Ks were 0.07 (+/-0.008) h-1 and 1.65 (+/-2.06) mg/L. In the SSTR the kinetic parameters mu max and Ks at room temperature were determined to be 0.12 (+/-0.009) h-1 and 2.18 (+/-0.47) mg/L, respectively. Although the mu max values for both types of reactors were similar, the shaker flask experiments resulted in considerable error. Error analysis on calculated values of Ks were found to impact estimates in atrazine concentration by as much as two orders of magnitude, depending on the reactor design, illustrating the importance of these factors in reactor scale-up.

  15. Environmental assessment of solid waste landfilling technologies by means of LCA-modeling

    DEFF Research Database (Denmark)

    Manfredi, Simone; Christensen, Thomas Højlund

    2009-01-01

    -aerobic landfill) and assesses the influence of the active operations practiced on these performances. The environmental assessments have been performed by means of the LCA-based tool EASEWASTE, whereby the functional unit utilized for the LCA is “landfilling of 1 ton of wet household waste in a 10 m deep landfill...... should be taken to prevent leachate infiltration to groundwater and it is essential to collect and treat the generated leachate. The bioreactor technologies recirculate the collected leachate to enhance the waste degradation process. This allows the gas collection period to be reduced from 40 to 15 years......, although it does not lead to noticeable environmental benefits when considering a 100 years LCA-perspective. In order to more comprehensively understand the influence of the active operations (i.e., leachate recirculation, waste flushing and air injection) on the environmental performance, the time horizon...

  16. Methane elimination methods on landfills

    OpenAIRE

    Ponikvar, Martin

    2008-01-01

    Increase in substance and energy exploitation from waste which reduces the greenhouse gas emissions are one of the main goals of environmental protection. Slovenian legislation defines that in case captured landfill gas cannot be used for energy acquisition, incineration on the landfill itself or some other equivalent procedure must be used to prevent gas emissions into the air. The graduation thesis is based on existing municipal landfill Volče where suitable gas elimination is yet to be arr...

  17. A comparative study of leachate quality and biogas generation in simulated anaerobic and hybrid bioreactors.

    Science.gov (United States)

    Xu, Qiyong; Tian, Ying; Wang, Shen; Ko, Jae Hac

    2015-07-01

    Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10months. The hybrid bioreactors were operated in an aerobic-anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia-nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75d and 60d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4L/kgvs and 113.2L/kgvs. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens.

  18. Use of Doehlert and constrained mixture designs in the development of a photo-oxidation procedure using UV radiation/H₂O₂ for decomposition of landfill leachate samples and determination of metals by flame atomic absorption spectrometry.

    Science.gov (United States)

    Bezerra, Marcos A; Souza, Antônio D S; Oliveira, Rafael V; Oliveira, Djalma M; Cardoso, Luiz A M; Sousa Filho, Hélio R

    2015-03-01

    This work proposes the use of photo-oxidation degradation with UV radiation/H2O2 as sample treatment for the determination of Fe, Zn, Mn, Ni and Co in municipal solid waste landfill leachate by flame atomic absorption spectrometry (FAAS). Three variables (pH, irradiation time and buffer concentration) were optimized using Doehlert design and the proportions of mixture components submitted to UV radiation (leachate sample, buffer solution and H2O2 30%, v/v) were optimized using a constrained mixture design. Using the experimental conditions established, this procedure allows limits of detection of 0.075, 0.025, 0.010, 0.075 and 0.041 µg mL-1, and the precision levels expressed as relative standard (%RSD, 0.5 µg mL-1) were 3.6, 1.8, 1.3, 3.3 and 1.7%, for Fe, Mn, Zn, Ni and Co respectively. Recovery tests were carried out for evaluation of the procedure accuracy and recoveries were between 92 and 106% for the studied metals. This procedure has been applied for the analysis of the landfill leachate collected in Jequié, a city of the southwestern region of the State of Bahia, Brazil. The results were compared with those obtained by acid digestion. There was no significant difference between the results obtained by the two methods based on paired t-test at 95% confidence level.

  19. Use of Doehlert and constrained mixture designs in the development of a photo-oxidation procedure using UV radiation/H2O2 for decomposition of landfill leachate samples and determination of metals by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Marcos A. Bezerra

    2015-03-01

    Full Text Available This work proposes the use of photo-oxidation degradation with UV radiation/H2O2 as sample treatment for the determination of Fe, Zn, Mn, Ni and Co in municipal solid waste landfill leachate by flame atomic absorption spectrometry (FAAS. Three variables (pH, irradiation time and buffer concentration were optimized using Doehlert design and the proportions of mixture components submitted to UV radiation (leachate sample, buffer solution and H2O2 30%, v/v were optimized using a constrained mixture design. Using the experimental conditions established, this procedure allows limits of detection of 0.075, 0.025, 0.010, 0.075 and 0.041 µg mL-1, and the precision levels expressed as relative standard (%RSD, 0.5 µg mL-1 were 3.6, 1.8, 1.3, 3.3 and 1.7%, for Fe, Mn, Zn, Ni and Co respectively. Recovery tests were carried out for evaluation of the procedure accuracy and recoveries were between 92 and 106% for the studied metals. This procedure has been applied for the analysis of the landfill leachate collected in Jequié, a city of the southwestern region of the State of Bahia, Brazil. The results were compared with those obtained by acid digestion. There was no significant difference between the results obtained by the two methods based on paired t-test at 95% confidence level.

  20. The bioreactor: a powerful tool for large-scale culture of animal cells.

    Science.gov (United States)

    Wang, Dianliang; Liu, Wanshun; Han, Baoqin; Xu, Ruian

    2005-10-01

    Bioreactors play a key role in the field of biologics, where they are used for the production of recombinant therapeutic proteins by large-scale cultivation of animal cells. There are several types of bioreactors, including stirred-tank, airlift, hollow-fiber, and Rotary Cell Culture System (RCCS) designs. The stirred-tank bioreactor is one of the most commonly used types, and is used both for industrial applications and laboratory research. The RCCS, invented by NASA, is increasingly used in the area of tissue engineering for medical purposes. Important improvements have been made in the design of traditional bioreactors, and new types of bioreactor are also being developed such as Couette-Taylor bioreactor, multifunctional-membrane bioreactor, and shaking bioreactor. Work is also progressing on techniques to improve the performance of bioreactors, including perfusion culture, the use of microcarriers, and methods of suppressing apoptosis and of monitoring cell growth in real time. Given the demand for the production by animal cells for use in the growing number of clinical applications, further advances in bioreactor technology can be expected during the next few years. Two main goals will be pursued: firstly, to increase output by high density cultivation of animal cells to produce high value protein pharmaceutics or viral vectors for clinical gene therapy; and secondly, to create a three-dimension space similar to that of an in vivo environment to regenerate tissue or organ and to reproduce valuable cells that are hard to culture in the traditional culture system.

  1. Energy efficiency in membrane bioreactors.

    Science.gov (United States)

    Barillon, B; Martin Ruel, S; Langlais, C; Lazarova, V

    2013-01-01

    Energy consumption remains the key factor for the optimisation of the performance of membrane bioreactors (MBRs). This paper presents the results of the detailed energy audits of six full-scale MBRs operated by Suez Environnement in France, Spain and the USA based on on-site energy measurement and analysis of plant operation parameters and treatment performance. Specific energy consumption is compared for two different MBR configurations (flat sheet and hollow fibre membranes) and for plants with different design, loads and operation parameters. The aim of this project was to understand how the energy is consumed in MBR facilities and under which operating conditions, in order to finally provide guidelines and recommended practices for optimisation of MBR operation and design to reduce energy consumption and environmental impacts.

  2. Nitrogen removal pathway of anaerobic ammonium oxidation in on-site aged refuse bioreactor.

    Science.gov (United States)

    Wang, Chao; Zhao, Youcai; Xie, Bing; Peng, Qing; Hassan, Muhammad; Wang, Xiaoyuan

    2014-05-01

    The nitrogen removal pathways and nitrogen-related functional genes in on-site three-stage aged refuse bioreactor (ARB) treating landfill leachate were investigated. It was found that on average 90.0% of CODCr, 97.6% of BOD5, 99.3% of NH4(+)-N, and 81.0% of TN were removed with initial CODCr, BOD5, NH4(+)-N, and TN concentrations ranging from 2323 to 2754, 277 to 362, 1237 to 1506, and 1251 to 1580 mg/L, respectively. Meanwhile, the functional genes amoA, nirS and anammox 16S rRNA gene were found to coexist in every bioreactor, and their relative proportions in each bioreactor were closely related to the pollutant removal performance of the corresponding bioreactor, which indicated the coexistence of multiple nitrogen removal pathways in the ARB. Detection of anammox expression proved the presence of the anammox nitrogen removal pathway during the process of recirculating mature leachate to the on-site ARB, which provides important information for nitrogen management in landfills.

  3. Migration behavior of landfill leachate contaminants through alternative composite liners

    Energy Technology Data Exchange (ETDEWEB)

    Varank, Gamze, E-mail: gvarank@yildiz.edu.tr; Demir, Ahmet, E-mail: ahmetd@yildiz.edu.tr; Top, Selin, E-mail: stop@yildiz.edu.tr; Sekman, Elif, E-mail: esekman@yildiz.edu.tr; Akkaya, Ebru, E-mail: ekoca@yildiz.edu.tr; Yetilmezsoy, Kaan, E-mail: yetilmez@yildiz.edu.tr; Bilgili, M. Sinan, E-mail: mbilgili@yildiz.edu.tr

    2011-08-01

    Four identical pilot-scale landfill reactors with different alternative composite liners were simultaneously operated for a period of about 540 days to investigate and to simulate the migration behaviors of phenolic compounds (phenol, 2-CP, 2-MP, 3-MP, 4-MP, 2-NP, 4-NP, 2,4-DNP, 2,4-DCP, 2,6-DCP, 2,4,5-TCP, 2,4,6-TCP, 2,3,4,6-TeCP, PCP) and heavy metals (Pb, Cu, Zn, Cr, Cd, Ni) from landfill leachate to the groundwater. Alternative landfill liners of four reactors consist of R1: Compacted clay liner (10 cm + 10 cm, k = 10{sup -8} m/sn), R2: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm + 10 cm, k = 10{sup -8} m/sn), R3: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm, k = 10{sup -8} m/sn) + bentonite liner (2 cm) + compacted clay liner (10 cm, k = 10{sup -8} m/sn), and R4: Geomembrane (2 mm HDPE) + compacted clay liner (10 cm, k = 10{sup -8} m/sn) + zeolite liner (2 cm) + compacted clay liner (10 cm, k = 10{sup -8} m/sn). Wastes representing Istanbul municipal solid wastes were disposed in the reactors. To represent bioreactor landfills, reactors were operated by leachate recirculation. To monitor and control anaerobic degradation in the reactors, variations of conventional parameters (pH, alkalinity, chloride, conductivity, COD, TOC, TKN, ammonia and alcaly metals) were also investigated in landfill leachate samples. The results of this study showed that about 35-50% of migration of organic contaminants (phenolic compounds) and 55-100% of migration of inorganic contaminants (heavy metals) to the model groundwater could be effectively reduced with the use of bentonite and zeolite materials in landfill liner systems. Although leachate contaminants can reach to the groundwater in trace concentrations, findings of this study concluded that the release of these compounds from landfill leachate to the groundwater may potentially be of an important environmental concern based on the experimental findings. - Research highlights: {yields} Migration of

  4. “膜生物反应器(MBR)+反渗透(RO)”工艺处理垃圾渗滤液项目调试运行%Debugging and Running of the Membrane Bioreactor (MBR) + Reverse Osmosis (RO) Process for Landfill Leachate Treatment Project

    Institute of Scientific and Technical Information of China (English)

    况柏华

    2012-01-01

    通过对广州市兴丰生活垃圾卫生填埋场渗滤液处理厂扩容工程的调试运行,表明采用"膜生物反应器(MBR)+反渗透(RO)"工艺处理垃圾渗滤液存在设备维护简单、处理效果稳定等特点,出水各项指标均优于《生活垃圾填埋场污染控制标准》(GB16889-2008)一般地区一级排放标准要求。%Through debugging and running on the Guangzhou City Xingfeng waste sanitary landfill leachate treatment plant expansion project,indicating that the process of a membrane biological reactor(MBR) + reverse osmosis(RO) "landfill leachate exist simple maintenance of equipment,processing the effect of stability and other characteristics of the effluent of the indicators were better than "municipal solid waste landfill pollution control standards"(GB16889-2008) the general area of A emission standard requirements.

  5. Landfill gas from environment to energy

    Energy Technology Data Exchange (ETDEWEB)

    Gendebien, A.; Pauwels, M.; Constant, M.; Ledrut-Damanet, M.J.; Nyns, E.J. [Louvain Univ. (Belgium); Fabry, R.; Ferrero, G.L. [Commission of the European Communities, Brussels (Belgium); Willumsen, H.C.; Butson, J.

    1992-11-01

    Landfill gas is an alternative source of energy which can be commercially exploited wherever municipal solid wastes are disposed of in sanitary landfills. In this context, it was decided to launch a comprehensive study on the subject of energy valorization of landfill gas. The main topics dealt with in the study, which is supported by a comprehensive literature survey and six detailed case-studies, include; (i) the environmental impact of landfill gas, (ii) the process of landfill gas genesis and the technology of landfill gas control by its exploitation, (iii) the monitoring of landfill gas emissions, (iv) the policies and legal aspects of landfill gas in the European Community and in the world, (v) the estimation of landfill gas potentials and economics of landfill gas control and exploitation, (vi) the status of landfill gas exploitation in the European Community and in the world. (authors). refs., figs., tabs.

  6. Hepatocyte function within a stacked double sandwich culture plate cylindrical bioreactor for bioartificial liver system.

    Science.gov (United States)

    Xia, Lei; Arooz, Talha; Zhang, Shufang; Tuo, Xiaoye; Xiao, Guangfa; Susanto, Thomas Adi Kurnia; Sundararajan, Janani; Cheng, Tianming; Kang, Yuzhan; Poh, Hee Joo; Leo, Hwa Liang; Yu, Hanry

    2012-11-01

    Bioartificial liver (BAL) system is promising as an alternative treatment for liver failure. We have developed a bioreactor with stacked sandwich culture plates for the application of BAL. This bioreactor design addresses some of the persistent problems in flat-bed bioreactors through increasing cell packing capacity, eliminating dead flow, regulating shear stress, and facilitating the scalability of the bioreactor unit. The bioreactor contained a stack of twelve double-sandwich-culture plates, allowing 100 million hepatocytes to be housed in a single cylindrical bioreactor unit (7 cm of height and 5.5 cm of inner diameter). The serial flow perfusion through the bioreactor increased cell-fluid contact area for effective mass exchange. With the optimal perfusion flow rate, shear stress was minimized to achieve high and uniform cell viabilities across different plates in the bioreactor. Our results demonstrated that hepatocytes cultured in the bioreactor could re-establish cell polarity and maintain liver-specific functions (e.g. albumin and urea synthesis, phase I&II metabolism functions) for seven days. The single bioreactor unit can be readily scaled up to house adequate number of functional hepatocytes for BAL development.

  7. Hydrofocusing Bioreactor for Three-Dimensional Cell Culture

    Science.gov (United States)

    Gonda, Steve R.; Spaulding, Glenn F.; Tsao, Yow-Min D.; Flechsig, Scott; Jones, Leslie; Soehnge, Holly

    2003-01-01

    The hydrodynamic focusing bioreactor (HFB) is a bioreactor system designed for three-dimensional cell culture and tissue-engineering investigations on orbiting spacecraft and in laboratories on Earth. The HFB offers a unique hydrofocusing capability that enables the creation of a low-shear culture environment simultaneously with the "herding" of suspended cells, tissue assemblies, and air bubbles. Under development for use in the Biotechnology Facility on the International Space Station, the HFB has successfully grown large three-dimensional, tissuelike assemblies from anchorage-dependent cells and grown suspension hybridoma cells to high densities. The HFB, based on the principle of hydrodynamic focusing, provides the capability to control the movement of air bubbles and removes them from the bioreactor without degrading the low-shear culture environment or the suspended three-dimensional tissue assemblies. The HFB also provides unparalleled control over the locations of cells and tissues within its bioreactor vessel during operation and sampling.

  8. A comparative study of leachate quality and biogas generation in simulated anaerobic and hybrid bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qiyong; Tian, Ying; Wang, Shen; Ko, Jae Hac, E-mail: jaehacko@pkusz.edu.cn

    2015-07-15

    Highlights: • Temporary aeration shortened the initial acid inhibition phase for methanogens. • COD decreased faster in the hybrid bioreactor than that in the anaerobic control. • Methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. • MSW settlement increased with increasing the frequency of intermittent aeration. - Abstract: Research has been conducted to compare leachate characterization and biogas generation in simulated anaerobic and hybrid bioreactor landfills with typical Chinese municipal solid waste (MSW). Three laboratory-scale reactors, an anaerobic (A1) and two hybrid bioreactors (C1 and C2), were constructed and operated for about 10 months. The hybrid bioreactors were operated in an aerobic–anaerobic mode with different aeration frequencies by providing air into the upper layer of waste. Results showed that the temporary aeration into the upper layer aided methane generation by shortening the initial acidogenic phase because of volatile fatty acids (VFAs) reduction and pH increase. Chemical oxygen demand (COD) decreased faster in the hybrid bioreactors, but the concentrations of ammonia–nitrogen in the hybrid bioreactors were greater than those in the anaerobic control. Methanogenic conditions were established within 75 d and 60 d in C1 and C2, respectively. However, high aeration frequency led to the consumption of organic matters by aerobic degradation and resulted in reducing accumulative methane volume. The temporary aeration enhanced waste settlement and the settlement increased with increasing the frequency of aeration. Methane production was inhibited in the anaerobic control; however, the total methane generations from hybrid bioreactors were 133.4 L/kg{sub vs} and 113.2 L/kg{sub vs}. As for MSW with high content of food waste, leachate recirculation right after aeration stopped was not recommended due to VFA inhibition for methanogens.

  9. Landfill Construction and Capacity Expansion

    NARCIS (Netherlands)

    Andre, F.J.; Cerda, E.

    2003-01-01

    We study the optimal capacity and lifetime of landfills taking into account their sequential nature.Such an optimal capacity is characterized by the so-called Optimal Capacity Condition.Particular versions of this condition are obtained for two alternative settings: first, if all the landfills are t

  10. Stabilizing Waste Materials for Landfills

    Science.gov (United States)

    Environmental Science and Technology, 1977

    1977-01-01

    The test procedures used to evaluate the suitability of landfilled materials of varying stability and to determine the leachate from such materials are reviewed. A process for stabilizing a mixture of sulfur dioxide sludge, fly ash, and bottom ash with lime and other additives for deposition in landfills is detailed. (BT)

  11. Landfill gas as vehicle fuel; Deponigas som fordonsbraensle

    Energy Technology Data Exchange (ETDEWEB)

    Benjaminsson, Johan; Johansson, Nina; Karlsvaerd, Johan (Grontmij AB, Stockholm (Sweden))

    2010-03-15

    The landfill gas extraction in Sweden 2008 was 370 GWh. Mainly because of lack of available technologies for landfill gas upgrading and high assessed upgrading costs, landfill gas has so far only been used for heating and cogenerations plants (CHP). In recent years, interest has been brought to upgrade landfill gas and this study highlights the possibility of using landfill gas as fuel for vehicles. A decision in investment in an upgrading installation requires a forecast of future gas production and landfill gas extraction. From 2005, dispose of organic waste is prohibited, reducing the number of active landfills and the landfill gas production will go down. Factors such as moisture content, design of the final coverage and landfill gas collection system have a major impact on the extraction. It is therefore difficult to make appropriate predictions of the future gas production. Today's landfill gas extraction is approximately 35% of the landfill gas production and in the light of this, extraction can be in a level comparable to today's at least ten years ahead, provided that the extraction system is being expanded and that measurements are taken to so that landfills should not dry out. In comparison with biogas from anaerobic digestion in a dedicated digester, landfill gas has a high percentage of nitrogen and a content of many contaminants such as organic silicon compounds (siloxanes) and halogenated hydrocarbons (hydrocarbons containing the halogens chlorine, fluorine and bromine). This often requires more treatment and a further separation step. A common method for purification of landfill gas is regenerative adsorption on a dedicated adsorption material. Carbon dioxide is separated by conventional techniques like PSA, water scrubber and membranes. The main barrier to use landfill gas as vehicle fuel is a cost-effective separation of nitrogen that does not generate high methane losses. Nitrogen is separated by PSA or distillation technique (cryogenic

  12. Application of Grey Situation Decision-Making Theory in Site Selection of a Waste Sanitary Landfill

    Institute of Scientific and Technical Information of China (English)

    CAO Li-wen; CHENG Yun-huan; ZHANG Jing; ZHOU Xiao-zhi; LIAN Cui-xia

    2006-01-01

    An application of an unequal-weighted multi-objective decision making method in site selection of a waste sanitary landfill is discussed. The eight factors, which affected possible options, were: size and capacity of the landfill, permeability of the stratum, the average difference in elevation between the groundwater level and the bottom of the landfill pit, quality and source of clay, the quality grade of the landfill site, the effect of landfill engineering on nearby residents, distance to the water supply and the water source as well as the cost of construction and waste transport. These are determined, given the conditions of the geological environment, the need for environmental protection and landfill site construction and transportation related to the design and operation of a sanitary landfill. The weights of the eight factors were further investigated based on the difference in their relevance. Combined with practical experience from Xuzhou city (Jiangsu province, China), the objectives, effects and weights of grey decision-making were determined and the process and outcome of the landfill site selection are stated in detail. The decision-making results have been proven to be acceptable and correct. As we show, unequal-weighted multi-objective grey situation decision-mak- ing is characterized by easy calculations and good maneuverability when used in landfill site selection. The number of factors (objectives) affecting the outcome and the quantitative method of qualitative indices can be adjusted on the basis of concrete conditions in landfill site selection. Therefore, unequal-weighted multi-objective grey situation decision making is a feasible method in selecting landfill sites which offers a reference method for landfill site selection elsewhere. It is a useful, rational and scientific exploration in the choice of a landfill site.

  13. Development of a bioreactor based on magnetically stabilized fluidized bed for bioartificial liver.

    Science.gov (United States)

    Deng, Fei; Chen, Li; Zhang, Ying; Zhao, Shan; Wang, Yu; Li, Na; Li, Shen; Guo, Xin; Ma, Xiaojun

    2015-12-01

    Bioartificial liver (BAL) based on microcapsules has been proposed as a potential treatment for acute liver failure. The bioreactors used in such BAL are usually expected to achieve sufficient flow rate and minimized void volume for effective application. Due to the superiorities in bed pressure drop and operation velocity, magnetically stabilized fluidized beds (MSFBs) show the potential to serve as ideal microcapsule-based bioreactors. In the present study, we attempted to develop a microcapsule-based MSFB bioreactor for bioartificial liver device. Compared to conventional-fluidized bed bioreactors, the bioreactor presented here increased perfusion velocity and decreased void volume significantly. Meanwhile, the mechanical stability as well as the immunoisolation property of magnetite microcapsules were well maintained during the fluidization. Besides, the magnetite microcapsules were found no toxicity to cell survival. Therefore, our study might provide a novel approach for the design of microcapsule-based bioartificial liver bioreactors.

  14. ENGINEERING ASPECTS OF LANDFILLING MUNICIPAL SOLID WASTE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Sanitary landfilling is the most important method of municipalsolid waste disposal in China. Landfill sites are always set up in mountain valley, on plain or beside seashore. A complete landfill consists of base system, cover system, and leachate collection and gas extraction system. This paper reviews the state-of-the-art landfilling technology in China and collection discusses research projects for engineers.

  15. Field assessment of semi-aerobic condition and the methane correction factor for the semi-aerobic landfills provided by IPCC guidelines.

    Science.gov (United States)

    Jeong, Sangjae; Nam, Anwoo; Yi, Seung-Muk; Kim, Jae Young

    2015-02-01

    According to IPCC guidelines, a semi-aerobic landfill site produces one-half of the amount of CH4 produced by an equally-sized anaerobic landfill site. Therefore categorizing the landfill type is important on greenhouse gas inventories. In order to assess semi-aerobic condition in the sites and the MCF value for semi-aerobic landfill, landfill gas has been measured from vent pipes in five semi-aerobically designed landfills in South Korea. All of the five sites satisfied requirements of semi-aerobic landfills in 2006 IPCC guidelines. However, the ends of leachate collection pipes which are main entrance of air in the semi-aerobic landfill were closed in all five sites. The CH4/CO2 ratio in landfill gas, indicator of aerobic and anaerobic decomposition, ranged from 1.08 to 1.46 which is higher than the values (0.3-1.0) reported for semi-aerobic landfill sites and is rather close to those (1.0-2.0) for anaerobic landfill sites. The low CH4+CO2% in landfill gas implied air intrusion into the landfill. However, there was no evidence that air intrusion has caused by semi-aerobic design and operation. Therefore, the landfills investigated in this study are difficult to be classified as semi-aerobic landfills. Also MCF of 0.5 may significantly underestimate methane emissions compared to other researches. According to the carbon mass balance analyses, the higher MCF needs to be proposed for semi-aerobic landfills. Consequently, methane emission estimate should be based on field evaluation for the semi-aerobically designed landfills. Copyright © 2015. Published by Elsevier Ltd.

  16. Development of a Laminar Flow Bioreactor by Computational Fluid Dynamics

    Directory of Open Access Journals (Sweden)

    Meir Israelowitz

    2012-01-01

    Full Text Available The purpose of this study is to improve the design of a bioreactor for growing bone and other three-dimensional tissues using a computational fluid dynamics (CFD software to simulate flow through a porous scaffold, and to recommend design changes based on the results. Basic requirements for CFD modeling were that the flow in the reactor should be laminar and any flow stagnation should be avoided in order to support cellular growth within the scaffold. We simulated three different designs with different permeability values of the scaffold and tissue. Model simulation addressed flow patterns in combination with pressure distribution within the bioreactor. Pressure build-up and turbulent flow within the reactor was solved by introduction of an integrated bypass system for pressure release. The use of CFD afforded direct feedback to optimize the bioreactor design.

  17. Enhanced Denitrification in Roadside Ditches with Bioreactors

    Science.gov (United States)

    Pluer, W.; Schneider, R.; Walter, M. T.

    2016-12-01

    Nitrate (NO3) pollution remains a water quality problem in agriculture-dominated watersheds despite decades of research and concerted efforts. Excess NO3 causes eutrophication in estuarine and marine ecosystems far downstream of the pollution source. Denitrification reduces NO3 to inert dinitrogen gas; this process occurs naturally in saturated areas of the landscape but this rate cannot keep up with the runoff rate due to fertilizer and manure applications. Researchers developed denitrifying bioreactors as a solution to encourage denitrification at the field level. Denitrifying bioreactors remove NO3 at a significantly higher rate (>2 g N m-2 d-1) than natural systems such as wetlands (<0.5 g N m-2 d-1). Most current designs of denitrifying bioreactors necessitate connection with tile drainage as the inflow source of water and NO3. It also requires a portion of farmland (typically <1% of field area is needed) which farmers can be reluctant to relinquish. Meanwhile, road ditches commonly run along agricultural fields, channeling runoff and NO3 to surface water. Because the ditches are designed to avoid flooding, they channel water rapidly and minimize time and contact with soil microbes for denitrification (denitrification rates in ditches are typically <0.1 g N m-2 d-1). Modified denitrifying bioreactors placed in road ditches could provide high NO3 removal in already marginal land, especially at baseflow conditions. A pilot study of this shows instantaneous NO3 removal rates up to 110 g N m-2 d-1 in the first year. Continued results similar to this pilot study and wider application could significantly increase ditch denitrification and help mitigate NO3 pollution.

  18. 40 CFR 62.14353 - Standards for municipal solid waste landfill emissions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Standards for municipal solid waste... POLLUTANTS Federal Plan Requirements for Municipal Solid Waste Landfills That Commenced Construction Prior to... municipal solid waste landfill emissions. (a) The owner or operator of a designated facility having a...

  19. Modeling and mitigation of denitrification 'woodchip' bioreactor phosphorus releases during treatment of aquaculture wastewater

    Science.gov (United States)

    Denitrification 'woodchip' bioreactors designed to remove nitrate from agricultural waters may either be phosphorus sources or sinks. A 24 d batch test showed woodchip leaching is an important source of phosphorus during bioreactor start-up with a leaching potential of approximately 20 -30 mg P per ...

  20. Optimizing hydraulic retention times in denitrifying woodchip bioreactors treating recirculating aquaculture system wastewater

    Science.gov (United States)

    The performance of wood-based denitrifying bioreactors to treat high-nitrate wastewaters from aquaculture systems has not previously been demonstrated. Four pilot-scale woodchip bioreactors (approximately 1:10 scale) were constructed and operated for 268 d to determine the optimal range of design hy...

  1. Propagation and Dissolution of CO2 bubbles in Algae Photo-bioreactors

    Science.gov (United States)

    Kosaraju, Srinivas

    2015-11-01

    Research grade photo-bioreactors are used to study and cultivate different algal species for biofuel production. In an attempt to study the growth properties of a local algal species in rain water, a custom made bioreactor is designed and being tested. Bio-algae consumes dissolved CO2 in water and during its growth cycle, the consumed CO2 must be replenished. Conventional methods use supply of air or CO2 bubbles in the growth medium. The propagation and dissolution of the bubbles, however, are strongly dependent on the design parameters of the photo-bioreactor. In this paper, we discuss the numerical modeling of the air and CO2 bubble propagation and dissolution in the photo-bioreactor. Using the results the bioreactor design will be modified for maximum productivity.

  2. Landfill aeration for emission control before and during landfill mining.

    Science.gov (United States)

    Raga, Roberto; Cossu, Raffaello; Heerenklage, Joern; Pivato, Alberto; Ritzkowski, Marco

    2015-12-01

    The landfill of Modena, in northern Italy, is now crossed by the new high velocity railway line connecting Milan and Bologna. Waste was completely removed from a part of the landfill and a trench for the train line was built. With the aim of facilitating excavation and further disposal of the material extracted, suitable measures were defined. In order to prevent undesired emissions into the excavation area, the aerobic in situ stabilisation by means of the Airflow technology took place before and during the Landfill Mining. Specific project features involved the pneumatic leachate extraction from the aeration wells (to keep the leachate table low inside the landfill and increase the volume of waste available for air migration) and the controlled moisture addition into a limited zone, for a preliminary evaluation of the effects on process enhancement. Waste and leachate were periodically sampled in the landfill during the aeration before the excavation, for quality assessment over time; the evolution of biogas composition in the landfill body and in the extraction system for different plant set-ups during the project was monitored, with specific focus on uncontrolled migration into the excavation area. Waste biological stability significantly increased during the aeration (waste respiration index dropped to 33% of the initial value after six months). Leachate head decreased from 4 to 1.5m; leachate recirculation tests proved the beneficial effects of moisture addition on temperature control, without hampering waste aerobization. Proper management of the aeration plant enabled the minimization of uncontrolled biogas emissions into the excavation area.

  3. Landfill Gas Energy Cost Model Version 3.0 (LFGcost-Web V3 ...

    Science.gov (United States)

    To help stakeholders estimate the costs of a landfill gas (LFG) energy project, in 2002, LMOP developed a cost tool (LFGcost). Since then, LMOP has routinely updated the tool to reflect changes in the LFG energy industry. Initially the model was designed for EPA to assist landfills in evaluating the economic and financial feasibility of LFG energy project development. In 2014, LMOP developed a public version of the model, LFGcost-Web (Version 3.0), to allow landfill and industry stakeholders to evaluate project feasibility on their own. LFGcost-Web can analyze costs for 12 energy recovery project types. These project costs can be estimated with or without the costs of a gas collection and control system (GCCS). The EPA used select equations from LFGcost-Web to estimate costs of the regulatory options in the 2015 proposed revisions to the MSW Landfills Standards of Performance (also known as New Source Performance Standards) and the Emission Guidelines (herein thereafter referred to collectively as the Landfill Rules). More specifically, equations derived from LFGcost-Web were applied to each landfill expected to be impacted by the Landfill Rules to estimate annualized installed capital costs and annual O&M costs of a gas collection and control system. In addition, after applying the LFGcost-Web equations to the list of landfills expected to require a GCCS in year 2025 as a result of the proposed Landfill Rules, the regulatory analysis evaluated whether electr

  4. High-throughput miniaturized bioreactors for cell culture process development: reproducibility, scalability, and control.

    Science.gov (United States)

    Rameez, Shahid; Mostafa, Sigma S; Miller, Christopher; Shukla, Abhinav A

    2014-01-01

    Decreasing the timeframe for cell culture process development has been a key goal toward accelerating biopharmaceutical development. Advanced Microscale Bioreactors (ambr™) is an automated micro-bioreactor system with miniature single-use bioreactors with a 10-15 mL working volume controlled by an automated workstation. This system was compared to conventional bioreactor systems in terms of its performance for the production of a monoclonal antibody in a recombinant Chinese Hamster Ovary cell line. The miniaturized bioreactor system was found to produce cell culture profiles that matched across scales to 3 L, 15 L, and 200 L stirred tank bioreactors. The processes used in this article involve complex feed formulations, perturbations, and strict process control within the design space, which are in-line with processes used for commercial scale manufacturing of biopharmaceuticals. Changes to important process parameters in ambr™ resulted in predictable cell growth, viability and titer changes, which were in good agreement to data from the conventional larger scale bioreactors. ambr™ was found to successfully reproduce variations in temperature, dissolved oxygen (DO), and pH conditions similar to the larger bioreactor systems. Additionally, the miniature bioreactors were found to react well to perturbations in pH and DO through adjustments to the Proportional and Integral control loop. The data presented here demonstrates the utility of the ambr™ system as a high throughput system for cell culture process development.

  5. Replaceable Sensor System for Bioreactor Monitoring

    Science.gov (United States)

    Mayo, Mike; Savoy, Steve; Bruno, John

    2006-01-01

    A sensor system was proposed that would monitor spaceflight bioreactor parameters. Not only will this technology be invaluable in the space program for which it was developed, it will find applications in medical science and industrial laboratories as well. Using frequency-domain-based fluorescence lifetime technology, the sensor system will be able to detect changes in fluorescence lifetime quenching that results from displacement of fluorophorelabeled receptors bound to target ligands. This device will be used to monitor and regulate bioreactor parameters including glucose, pH, oxygen pressure (pO2), and carbon dioxide pressure (pCO2). Moreover, these biosensor fluorophore receptor-quenching complexes can be designed to further detect and monitor for potential biohazards, bioproducts, or bioimpurities. Biosensors used to detect biological fluid constituents have already been developed that employ a number of strategies, including invasive microelectrodes (e.g., dark electrodes), optical techniques including fluorescence, and membrane permeable systems based on osmotic pressure. Yet the longevity of any of these sensors does not meet the demands of extended use in spacecraft habitat or bioreactor monitoring. It was therefore necessary to develop a sensor platform that could determine not only fluid variables such as glucose concentration, pO2, pCO2, and pH but can also regulate these fluid variables with controlled feedback loop.

  6. Comparative lysimeters studies for landfill leachate characterization and settlement variation in partly sorted municipal solid waste and fully sorted organic wastes.

    Science.gov (United States)

    Khan, A S; Narulkar, S M

    2010-04-01

    About three-quarters of the countries and territories around the world use crude 'open dumping' method of disposal for municipal solid waste (MSW) which is the easiest and cheapest method of removing waste from the immediate environment but it creates serious environmental problems like groundwater contamination and air pollution. Land-filling is considered to be the most cost-effective method for solid waste disposal in developing countries if adequate sites are available. Bioreactor landfill is a promising biotechnological option for faster stabilization of municipal solid waste. The bioreactor landfill provides control and process optimization, primarily through the addition ofleachate or other liquid amendments. In the present study, Lysimeter experiments were carried out for the comparison of leachate characterization and settlement variation of "MSW except recyclable and domestic hazardous wastes" and "organic waste" to know the bioreactor feasibility in Indian context, because in India organic content of the solid waste is more due to consumption of unprocessed food items. Three Lysimeters under different operational conditions have been experimented for leachate characterization and settlement variation of the wastes. The results indicate the faster decay of pollutants in bioreactor in comparison to open dumps. The trend indicating the decay of pollutants elements in the produced leachate is encouraging.

  7. Field assessment of semi-aerobic condition and the methane correction factor for the semi-aerobic landfills provided by IPCC guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Sangjae [Department of Civil and Environmental Engineering, College of Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Nam, Anwoo [Korea Environment Corporation, 42 Hwangyeong-ro, Seo-gu, Incheon 404-170 (Korea, Republic of); Yi, Seung-Muk [Department of Environmental Health, School of Public Health, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Jae Young, E-mail: jaeykim@snu.ac.kr [Department of Civil and Environmental Engineering, College of Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

    2015-02-15

    Highlights: • CH{sub 4}/CO{sub 2} and CH{sub 4} + CO{sub 2}% are proposed as indices to evaluate semi-aerobic landfills. • A landfill which CH{sub 4}/CO{sub 2} > 1.0 is difficult to be categorized as semi-aerobic landfill. • Field conditions should be carefully investigated to determine landfill types. • The MCF default value for semi-aerobic landfills underestimates the methane emissions. - Abstract: According to IPCC guidelines, a semi-aerobic landfill site produces one-half of the amount of CH{sub 4} produced by an equally-sized anaerobic landfill site. Therefore categorizing the landfill type is important on greenhouse gas inventories. In order to assess semi-aerobic condition in the sites and the MCF value for semi-aerobic landfill, landfill gas has been measured from vent pipes in five semi-aerobically designed landfills in South Korea. All of the five sites satisfied requirements of semi-aerobic landfills in 2006 IPCC guidelines. However, the ends of leachate collection pipes which are main entrance of air in the semi-aerobic landfill were closed in all five sites. The CH{sub 4}/CO{sub 2} ratio in landfill gas, indicator of aerobic and anaerobic decomposition, ranged from 1.08 to 1.46 which is higher than the values (0.3–1.0) reported for semi-aerobic landfill sites and is rather close to those (1.0–2.0) for anaerobic landfill sites. The low CH{sub 4} + CO{sub 2}% in landfill gas implied air intrusion into the landfill. However, there was no evidence that air intrusion has caused by semi-aerobic design and operation. Therefore, the landfills investigated in this study are difficult to be classified as semi-aerobic landfills. Also MCF of 0.5 may significantly underestimate methane emissions compared to other researches. According to the carbon mass balance analyses, the higher MCF needs to be proposed for semi-aerobic landfills. Consequently, methane emission estimate should be based on field evaluation for the semi-aerobically designed landfills.

  8. Construction and evaluation of urinary bladder bioreactor for urologic tissue-engineering purposes.

    LENUS (Irish Health Repository)

    Davis, Niall F

    2012-01-31

    OBJECTIVE: To design and construct a urinary bladder bioreactor for urologic tissue-engineering purposes and to compare the viability and proliferative activity of cell-seeded extracellular matrix scaffolds cultured in the bioreactor with conventional static growth conditions. MATERIALS AND METHODS: A urinary bladder bioreactor was designed and constructed to replicate physiologic bladder dynamics. The bioreactor mimicked the filling pressures of the human bladder by way of a cyclical low-delivery pressure regulator. In addition, cell growth was evaluated by culturing human urothelial cells (UCs) on porcine extracellular matrix scaffolds in the bioreactor and in static growth conditions for 5 consecutive days. The attachment, viability, and proliferative potential were assessed and compared with quantitative viability indicators and by fluorescent markers for intracellular esterase activity and plasma membrane integrity. Scaffold integrity was characterized with scanning electron microscopy and 4\\

  9. Residential landfill remedial action construction case history

    Energy Technology Data Exchange (ETDEWEB)

    Creamer, P.D.; Martin, K.E. [RMT, Inc., Madison, WI (United States); Fahrney, J.S. [City of Madison, WI (United States)

    1995-12-31

    The City of Madison - Mineral Point Park is located on Madison`s west side within a well-established neighborhood on approximately 11 acres of open green space, which was formerly the Mineral Point Landfill. In 1994, a comprehensive remedial action construction project was implemented to more effectively extract methane gas and control gas migration, to minimize potential groundwater contamination, and to improve surface water run-off controls. This was accomplished by installing two new gas extraction systems, constructing a 4-foot-thick composite final cover with a geosynthetic subsurface drainage system, and adding 12 feet of relief and a storm sewer system to promote positive surface water drainage. While these features alone are not uncommon to many other landfills, the challenging aspect of this project was to install them in extreme proximity to homes, condominiums, and a school that were quickly developed shortly after the landfill closed. Some of the issues unique to this project due to the residential setting included strict noise, dust, and odor controls, easement negotiations, limited hours of operation, limited material storage areas, utility relocations and crossings, continuous operation of the existing gas extraction system, limited construction access, and increased health and safety concerns for the general public. The need to keep the neighboring residents informed, as well as to address their concerns and requests, was also a critical requirement in both the design and construction phases. This paper will review the design of the remedial action plan and present the construction process, highlighting the constructability issues encountered and the innovative means to overcome them. The program for communication with the neighbors throughout the design and construction phases will also be addressed.

  10. Spiral vane bioreactor

    Science.gov (United States)

    Morrison, Dennis R. (Inventor)

    1991-01-01

    A spiral vane bioreactor of a perfusion type is described in which a vertical chamber, intended for use in a microgravity condition, has a central rotating filter assembly and has flexible membranes disposed to rotate annularly about the filter assembly. The flexible members have end portions disposed angularly with respect to one another. A fluid replenishment medium is input from a closed loop liquid system to a completely liquid filled chamber containing microcarrier beads, cells and a fluid medium. Output of spent medium is to the closed loop. In the closed loop, the output and input parameters are sensed by sensors. A manifold permits recharging of the nutrients and pH adjustment. Oxygen is supplied and carbon dioxide and bubbles are removed and the system is monitored and controlled by a microprocessor.

  11. [Transgenic animals bioreactors].

    Science.gov (United States)

    Gou, Ke-Mian; An, Xiao-Rong; Tian, Jian-Hui; Chen, Yong-Fu

    2002-01-01

    The production of human recombinant proteins in milk of transgenic farm animals offers a safe, very cost-effective source of commercially important proteins that cannot be produced as efficiently in adequate quantities by other methods. This review has summarized the current status of gene selection, vector construct, transgenic methods, economics, and obvious potential in transgenic animals bioreactors. Recently, a more powerful approach was adopted in the transgenic animals founded on the application of nuclear transfer. As we will illustrate, this strategy presents a breakthrough in the overall efficiency of generating transgenic farm animals, product consistency, and time of product development. The successful adaptation of Cre-/lox P-mediated site-specific DNA recombination systems in farm animals will offer unprecedented possibilities for generating transgenic animals.

  12. Controlled-Turbulence Bioreactors

    Science.gov (United States)

    Wolf, David A.; Schwartz, Ray; Trinh, Tinh

    1989-01-01

    Two versions of bioreactor vessel provide steady supplies of oxygen and nutrients with little turbulence. Suspends cells in environment needed for sustenance and growth, while inflicting less damage from agitation and bubbling than do propeller-stirred reactors. Gentle environments in new reactors well suited to delicate mammalian cells. One reactor kept human kidney cells alive for as long as 11 days. Cells grow on carrier beads suspended in liquid culture medium that fills cylindrical housing. Rotating vanes - inside vessel but outside filter - gently circulates nutrient medium. Vessel stationary; magnetic clutch drives filter cylinder and vanes. Another reactor creates even less turbulence. Oxygen-permeable tubing wrapped around rod extending along central axis. Small external pump feeds oxygen to tubing through rotary coupling, and oxygen diffuses into liquid medium.

  13. Hydrodynamic study to the bioreactor at the Granollers wastewater plant; Estudio hidrodinamico del reactor biologia de la EDAR Granollers

    Energy Technology Data Exchange (ETDEWEB)

    Olivet Santana, D.; Valls Puig, J.; Gordillo Bolasell, M. A.; Sanchez Ferrer, A.; Freixo Rey, A.

    2002-07-01

    One of the most important parameters affecting the operation of bioreactors used in the wastewater treatment is their hydrodynamic behaviour. Usually, bioreactors are designed according to ideal flow models, concretely stirred tank and plug flow models. However, actual bioreactors show a different behaviour from that predicted from ideal modelling. This fact is due to the presence of multiphase systems (e. g. biomass, liquid phase, air, etc.) and the yield obtained can significantly differ from theoretical design values. In the present work, residence-time distribution (RTD) is used to study a plug-flow bioreactor, which is currently working at the plant placed in Granollers (Barcelona). (Author) 5 refs.

  14. Fast multipoint immobilized MOF bioreactor.

    Science.gov (United States)

    Liu, Wan-Ling; Wu, Cheng-You; Chen, Chien-Yu; Singco, Brenda; Lin, Chia-Her; Huang, Hsi-Ya

    2014-07-14

    An enzyme-NBD@MOF bioreactor with exemplary proteolytic performance, even after successive reuse and storage, was produced through a novel, rapid and simple multipoint immobilization technique without chemical modification of the solid support. Enzyme loading and distribution could be directly monitored from the fluorescence emission of the bioreactor. The dye molecular dimension plays a role in its overall performance. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Bioreactor Mass Transport Studies

    Science.gov (United States)

    Kleis, Stanley J.; Begley, Cynthia M.

    1997-01-01

    The objectives of the proposed research efforts were to develop both a simulation tool and a series of experiments to provide a quantitative assessment of mass transport in the NASA rotating wall perfused vessel (RWPV) bioreactor to be flown on EDU#2. This effort consisted of a literature review of bioreactor mass transport studies, the extension of an existing scalar transport computer simulation to include production and utilization of the scalar, and the evaluation of experimental techniques for determining mass transport in these vessels. Since mass transport at the cell surface is determined primarily by the relative motion of the cell assemblage and the surrounding fluid, a detailed assessment of the relative motion was conducted. Results of the simulations of the motion of spheres in the RWPV under microgravity conditions are compared with flight data from EDU#1 flown on STS-70. The mass transport across the cell membrane depends upon the environment, the cell type, and the biological state of the cell. Results from a literature review of cell requirements of several scalars are presented. As a first approximation, a model with a uniform spatial distribution of utilization or production was developed and results from these simulations are presented. There were two candidate processes considered for the experimental mass transport evaluations. The first was to measure the dissolution rate of solid or gel beads. The second was to measure the induced fluorescence of beads as a stimulant (for example hydrogen peroxide) is infused into the vessel. Either technique would use video taped images of the process for recording the quantitative results. Results of preliminary tests of these techniques are discussed.

  16. Recycling of aged refuse from a closed landfill.

    Science.gov (United States)

    Zhao, Youcai; Song, Liyan; Huang, Renhua; Song, Lijie; Li, Xiong

    2007-04-01

    In this study, refuse excavated from a typical refuse landfill in Shanghai after 8-10 years of placement was characterized in terms of particle size, total nitrogen, total phosphorus, and biodegradable matter. The refuse contained a large and diverse population of micro-organisms with a high capacity for decomposing refractory organic matter present in some wastewaters, including leachate. It was found that the aged refuse was quite stable after about a decade of decomposition in the warm, humid climate of southern China. The fine fractions resembled and had the properties of black soil, a medium that is suitable for green construction, organic fertilizer, or as bioreactor media for biological treatment of organic wastewaters. Excavation of the aged refuse would make about 50% of the space available for fresh refuse. The plastics, glass, textiles, and cans can be readily mechanically separated and recycled after cleaning. It is estimated that at least 200 millions tonnes of such aged refuse are available in China alone, and at least 10 times that much is buried worldwide. Hence, the evaluation of mined landfill waste and consideration of its potential uses is of great significance.

  17. Characterization of thermal properties of municipal solid waste landfills.

    Science.gov (United States)

    Faitli, József; Magyar, Tamás; Erdélyi, Attila; Murányi, Attila

    2015-02-01

    Municipal waste landfills represent not only a source of landfill gases, but a source of thermal energy as well. The heat in landfills is generated by physical, chemical and microbiological processes. The goal of our study was to characterize the thermal properties of municipal solid waste (MSW) samples of the given landfill. A new apparatus was designed and constructed to measure heat flow. A systematic test series of 17 discrete measurements was carried out with municipal waste samples of 1.0-1.7 m(3). The thermal conductivity, heat diffusivity and specific heat capacity of the samples were determined. Analysing the results of the sampling and our experiments it was realized that the theoretical fundaments should be clarified. Two theories were developed for the serial and for the parallel heat flow in three phase disperse systems. The serial and parallel models resulted in different theoretical estimations. The measured thermal conductivity and heat diffusivity were better characterized by the parallel heat flow estimations. The results show that heat can flow parallel in solid, liquid and gas phases. Characterization of thermal properties serves to establish the fundament of heat extraction from municipal waste landfills.

  18. A novel bioreactor to simulate urinary bladder mechanical properties and compliance for bladder functional tissue engineering

    Institute of Scientific and Technical Information of China (English)

    WEI Xin; LI Dao-bing; XU Feng; WANG Yan; ZHU Yu-chun; LI Hong; WANG Kun-jie

    2011-01-01

    Background Bioreactors are pivotal tools for generating mechanical stimulation in functional tissue engineering study.This study aimed to create a bioreactor that can simulate urinary bladder mechanical properties, and to investigate the effects of a mechanically stimulated culture on urothelial cells and bladder smooth muscle cells.Methods We designed a bioreactor to simulate the mechanical properties of bladder. A pressure-record system was used to evaluate the mechanical properties of the bioreactor by measuring the pressure in culture chambers. To test the biocompatibility of the bioreactor, viabilities of urothelial cells and smooth muscle cells cultured in the bioreactor under static and mechanically changed conditions were measured after 7-day culture. To evaluate the effect of mechanical stimulations on the vital cells, urethral cells and smooth muscle cells were cultured in the simulated mechanical conditions. After that, the viability and the distribution pattern of the cells were observed and compared with cells cultured in non-mechanical stimulated condition.Results The bioreactor system successfully generated waveforms similar to the intended programmed model while maintaining a cell-seeded elastic membrane between the chambers. There were no differences between viabilities of urothelial cells ((91.90±1.22)% vs. (93.14±1.78)%, P >0.05) and bladder smooth muscle cells ((93.41±1.49)% vs.(92.61±1.34)%, P >0.05). The viability of cells and tissue structure observation after cultured in simulated condition showed that mechanical stimulation was the only factor affected cells in the bioreactor and improved the arrangement of cells on silastic membrane.Conclusions This bioreactor can effectively simulate the physiological and mechanical properties of the bladder.Mechanical stimulation is the only factor that affected the viability of cells cultured in the bioreactor. The bioreactor can change the growth behavior of urothelial cells and bladder smooth

  19. A novel bioreactor to simulate urinary bladder mechanical properties and compliance for bladder functional tissue engineering.

    Science.gov (United States)

    Wei, Xin; Li, Dao-bing; Xu, Feng; Wang, Yan; Zhu, Yu-chun; Li, Hong; Wang, Kun-jie

    2011-02-01

    Bioreactors are pivotal tools for generating mechanical stimulation in functional tissue engineering study. This study aimed to create a bioreactor that can simulate urinary bladder mechanical properties, and to investigate the effects of a mechanically stimulated culture on urothelial cells and bladder smooth muscle cells. We designed a bioreactor to simulate the mechanical properties of bladder. A pressure-record system was used to evaluate the mechanical properties of the bioreactor by measuring the pressure in culture chambers. To test the biocompatibility of the bioreactor, viabilities of urothelial cells and smooth muscle cells cultured in the bioreactor under static and mechanically changed conditions were measured after 7-day culture. To evaluate the effect of mechanical stimulations on the vital cells, urethral cells and smooth muscle cells were cultured in the simulated mechanical conditions. After that, the viability and the distribution pattern of the cells were observed and compared with cells cultured in non-mechanical stimulated condition. The bioreactor system successfully generated waveforms similar to the intended programmed model while maintaining a cell-seeded elastic membrane between the chambers. There were no differences between viabilities of urothelial cells ((91.90 ± 1.22)% vs. (93.14 ± 1.78)%, P > 0.05) and bladder smooth muscle cells ((93.41 ± 1.49)% vs. (92.61 ± 1.34)%, P > 0.05). The viability of cells and tissue structure observation after cultured in simulated condition showed that mechanical stimulation was the only factor affected cells in the bioreactor and improved the arrangement of cells on silastic membrane. This bioreactor can effectively simulate the physiological and mechanical properties of the bladder. Mechanical stimulation is the only factor that affected the viability of cells cultured in the bioreactor. The bioreactor can change the growth behavior of urothelial cells and bladder smooth muscle cells, resulting in

  20. LCA and economic evaluation of landfill leachate and gas technologies.

    Science.gov (United States)

    Damgaard, Anders; Manfredi, Simone; Merrild, Hanna; Stensøe, Steen; Christensen, Thomas H

    2011-07-01

    Landfills receiving a mix of waste, including organics, have developed dramatically over the last 3-4 decades; from open dumps to engineered facilities with extensive controls on leachate and gas. The conventional municipal landfill will in most climates produce a highly contaminated leachate and a significant amount of landfill gas. Leachate controls may include bottom liners and leachate collection systems as well as leachate treatment prior to discharge to surface water. Gas controls may include oxidizing top covers, gas collection systems with flares or gas utilization systems for production of electricity and heat. The importance of leachate and gas control measures in reducing the overall environmental impact from a conventional landfill was assessed by life-cycle-assessment (LCA). The direct cost for the measures were also estimated providing a basis for assessing which measures are the most cost-effective in reducing the impact from a conventional landfill. This was done by modeling landfills ranging from a simple open dump to highly engineered conventional landfills with energy recovery in form of heat or electricity. The modeling was done in the waste LCA model EASEWASTE. The results showed drastic improvements for most impact categories. Global warming went from an impact of 0.1 person equivalent (PE) for the dump to -0.05 PE for the best design. Similar improvements were found for photochemical ozone formation (0.02 PE to 0.002 PE) and stratospheric ozone formation (0.04 PE to 0.001 PE). For the toxic and spoiled groundwater impact categories the trend is not as clear. The reason for this was that the load to the environment shifted as more technologies were used. For the dump landfill the main impacts were impacts for spoiled groundwater due to lack of leachate collection, 2.3 PE down to 0.4 PE when leachate is collected. However, at the same time, leachate collection causes a slight increase in eco-toxicity and human toxicity via water (0.007 E to 0

  1. A review of landfill microbiology research

    Energy Technology Data Exchange (ETDEWEB)

    Archer, D.; Reynolds, P.; Blakey, N.C.

    1995-05-01

    In May 1994 the DTI through ETSU commissioned WRc to undertake a comprehensive review of the landfill microbiology programme to date. The review has attempted to identify remaining gaps in knowledge which are most likely to find application in controlling the production of gas from landfills, and concludes with a list of recommendations for specific landfill process research which is likely to facilitate and optimise energy recovery from landfill. (UK)

  2. Thermal inactivation of Bacillus anthracis surrogate spores in a bench-scale enclosed landfill gas flare.

    Science.gov (United States)

    Tufts, Jenia A McBrian; Rosati, Jacky A

    2012-02-01

    A bench-scale landfill flare system was designed and built to test the potential for landfilled biological spores that migrate from the waste into the landfill gas to pass through the flare and exit into the environment as viable. The residence times and temperatures of the flare were characterized and compared to full-scale systems. Geobacillus stearothermophilus and Bacillus atrophaeus, nonpathogenic spores that may serve as surrogates for Bacillus anthracis, the causative agent for anthrax, were investigated to determine whether these organisms would be inactivated or remain viable after passing through a simulated landfill flare. High concentration spore solutions were aerosolized, dried, and sent through a bench-scale system to simulate the fate of biological weapon (BW)-grade spores in a landfill gas flare. Sampling was conducted downstream of the flare using a bioaerosol collection device containing sterile white mineral oil. The samples were cultured, incubated for seven days, and assessed for viability. Results showed that the bench-scale system exhibited good similarity to the real-world conditions of an enclosed standard combustor flare stack with a single orifice, forced-draft diffusion burner. All spores of G. stearothermophilus and B. atrophaeus were inactivated in the flare, indicating that spores that become re-entrained in landfill gas may not escape the landfill as viable, apparently becoming completely inactivated as they exit through a landfill flare.

  3. On optimization design for a flood intercepting trench of solid waste sanitary landfill in Shaanxi province%陕西省某生活垃圾卫生填埋场泄洪沟设计分析

    Institute of Scientific and Technical Information of China (English)

    赵丰毅; 张莉平; 曹叶; 文国庆; 袁莹

    2012-01-01

    西北地区山谷形垃圾填埋场一般具有汇水面积大、土质疏松、易发生山体垮塌等特点,因而需进行降水拦截导排。以实际工程设计为基点,结合当地条件进行了基本参数的选取、断面比选、出口形式选择、消力区段设计计算等。针对场区地形高差大、坡度陡实际情况,给出了陡坡段消力设计计算的一般方法。%Valley-shaped solid waste sanitary landfill in northwest has generally the characteristics of large catchment area, loose soil and high incidence of mountain collapse, therefore, it is required to discharge the rainfall humanly. Based on the actual engineering design and combined with the local conditions, the selection of basic parameters, the choice of the section, outlet of the ditches and the calculation of hydraulic drop pipeline are discussed. According to the actual situation of high level difference and slope, general design and calculate method on hydraulic drop pipeline in slope area is given, and as well as a summary.

  4. Miniature Bioreactor System for Long-Term Cell Culture

    Science.gov (United States)

    Gonda, Steve R.; Kleis, Stanley J.; Geffert, Sandara K.

    2010-01-01

    A prototype miniature bioreactor system is designed to serve as a laboratory benchtop cell-culturing system that minimizes the need for relatively expensive equipment and reagents and can be operated under computer control, thereby reducing the time and effort required of human investigators and reducing uncertainty in results. The system includes a bioreactor, a fluid-handling subsystem, a chamber wherein the bioreactor is maintained in a controlled atmosphere at a controlled temperature, and associated control subsystems. The system can be used to culture both anchorage-dependent and suspension cells, which can be either prokaryotic or eukaryotic. Cells can be cultured for extended periods of time in this system, and samples of cells can be extracted and analyzed at specified intervals. By integrating this system with one or more microanalytical instrument(s), one can construct a complete automated analytical system that can be tailored to perform one or more of a large variety of assays.

  5. The Fluid Mechanics of a Wavy-Wall Bioreactor

    Science.gov (United States)

    Sucosky, Philippe; Bilgen, Bahar; Aleem, Alexander; Neitzel, Paul; Barabino, Gilda

    2004-11-01

    Bioreactors are devices used for the production of mammalian tissue in vitro. Although mixing has been shown to stimulate the growth of cartilage constructs, high shear-stress levels can damage the cells. In order to enhance mixing while minimizing shear, a wavy-wall bioreactor (WWB) featuring a sinusoidal internal profile has been designed. The turbulent hydrodynamic environment produced in this device is investigated experimentally using particle-image velocimetry. A model bioreactor made of acrylic and filled with an index-matching solution of zinc iodide is used to compensate for the refraction of light at the walls. The flow observed in different planes is shown to be periodic, spatially dependent, and dominated by mean-shear rather than Reynolds stresses in the vicinity of constructs. Finally, a comparison between the mean-shear stresses obtained in the WWB and in a standard spinner flask reveals similar stress levels near the construct walls.

  6. Landfilling of waste incineration residues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Cai, Zuansi

    2002-01-01

    Residues from waste incineration are bottom ashes and air-pollution-control (APC) residues including fly ashes. The leaching of heavy metals and salts from the ashes is substantial and a wide spectrum of leaching tests and corresponding criteria have been introduced to regulate the landfilling...... of the ashes. Leaching test, however, must be selected carefully to provide information relevant for the actual disposal scenario and for evaluating the benefits of pre-treating the residues prior to landfilling. This paper describes research at the Technical University of Denmark addressing some...... of these issues focusing on pH-development in landfilled residues, effects of leaching test conditions on Cr leaching and effects of pre-treatment with FeSO4....

  7. Sustainable treatment of landfill leachate

    Science.gov (United States)

    Kamaruddin, Mohamad Anuar; Yusoff, Mohd. Suffian; Aziz, Hamidi Abdul; Hung, Yung-Tse

    2015-06-01

    Landfill leachate is a complex liquid that contains excessive concentrations of biodegradable and non-biodegradable products including organic matter, phenols, ammonia nitrogen, phosphate, heavy metals, and sulfide. If not properly treated and safely disposed, landfill leachate could be an impending source to surface and ground water contamination as it may percolate throughout soils and subsoils, causing adverse impacts to receiving waters. Lately, various types of treatment methods have been proposed to alleviate the risks of untreated leachate. However, some of the available techniques remain complicated, expensive and generally require definite adaptation during process. In this article, a review of literature reported from 2008 to 2012 on sustainable landfill leachate treatment technologies is discussed which includes biological and physical-chemical techniques, respectively.

  8. Anaerobic membrane bioreactor under extreme conditions (poster)

    NARCIS (Netherlands)

    Munoz Sierra, J.D.; De Kreuk, M.K.; Spanjers, H.; Van Lier, J.B.

    2013-01-01

    Membrane bioreactors ensure biomass retention by the application of micro or ultrafiltration processes. This allows operation at high sludge concentrations. Previous studies have shown that anaerobic membrane bioreactors is an efficient way to retain specialist microorganisms for treating wastewater

  9. Aerobic SMBR/reverse osmosis system enhanced by Fenton oxidation for advanced treatment of old municipal landfill leachate.

    Science.gov (United States)

    Zhang, Guoliang; Qin, Lei; Meng, Qin; Fan, Zheng; Wu, Dexin

    2013-08-01

    A novel combined process of Fenton oxidation, submerged membrane bioreactor (SMBR) and reverse osmosis (RO) was applied as an appropriate option for old municipal landfill leachate treatment. Fenton process was designed to intensively solve the problem of non-biodegradable organic pollutant removal and low biodegradability of leachate, although the removal of ammonia-nitrogen was similar to 10%. After SMBR treatment, it not only presented a higher removal efficiency of organics, but also exhibited high ammonia-nitrogen removal of 80% on average. The variation of extracellular polymeric substance (EPS) content, zeta potential, and particle size of flocs after Fenton effluent continually fed in SMBR was found to be benefit for alleviating membrane fouling. Finally, three kinds of RO membranes (RE, CPA, and BW) were applied to treat SMBR effluents and successfully met wastewater re-utilization requirement. Compared with simple RO process, the troublesome membrane fouling can be effectively reduced in the combined process. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Landfilling of waste incineration residues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Cai, Zuansi

    2002-01-01

    Residues from waste incineration are bottom ashes and air-pollution-control (APC) residues including fly ashes. The leaching of heavy metals and salts from the ashes is substantial and a wide spectrum of leaching tests and corresponding criteria have been introduced to regulate the landfilling...... of the ashes. Leaching test, however, must be selected carefully to provide information relevant for the actual disposal scenario and for evaluating the benefits of pre-treating the residues prior to landfilling. This paper describes research at the Technical University of Denmark addressing some...

  11. Microfluidic bioreactors for culture of non-adherent cells

    DEFF Research Database (Denmark)

    Shah, Pranjul Jaykumar; Vedarethinam, Indumathi; Kwasny, Dorota

    2011-01-01

    Microfluidic bioreactors (μBR) are becoming increasingly popular for cell culture, sample preparation and analysis in case of routine genetic and clinical diagnostics. We present a novel μBR for non-adherent cells designed to mimic in vivo perfusion of cells based on diffusion of media through...

  12. Reduced Order Dead-Beat Observers for a Bioreactor

    CERN Document Server

    Karafyllis, Iasson

    2010-01-01

    This paper studies the strong observability property and the reduced-order dead-beat observer design problem for a continuous bioreactor. New relationships between coexistence and strong observability, and checkable sufficient conditions for strong observability, are established for a chemostat with two competing microbial species. Furthermore, the dynamic output feedback stabilization problem is solved for the case of one species.

  13. Exploring the potential of membrane bioreactors to enhance metals removal from wastewater: pilot experiences.

    Science.gov (United States)

    Fatone, F; Eusebi, A L; Pavan, P; Battistoni, P

    2008-01-01

    The potential of membrane bioreactors to enhance the removal of selected metals from low loaded sewages has been explored. A 1400 litre pilot plant, equipped with an industrial submerged module of hollow fibre membranes, has been used in three different configurations: membrane bioreactor, operating in sequencing batch modality, for the treatment of real mixed municipal/industrial wastewater; membrane-assisted biosorption reactor, for the treatment of real leachate from municipal landfills; continuously fed membrane bioreactor, for the treatment of water charged with cadmium and nickel ions. The results show that: (a) in treating wastewaters with low levels of heavy metals (high sludge ages is not an effective strategy to significantly enhance the metals removal; (b) Hg and Cd are effectively removed already in conventional systems with gravitational final clarifiers, while Cu, Cr, Ni can rely on a additional performance in membrane bioreactors; (c) the further membrane effect is remarkable for Cu and Cr, while it is less significant for Ni. Basically, similar membrane effects recur in three different experimental applications that let us estimate the potential of membrane system to retain selected metal complexes. The future development of the research will investigate the relations between the membrane effect and the manipulable filtration parameters (i.e., permeate flux, solids content, filtration cycle).

  14. Progress in bioreactors of bioartiifcial livers

    Institute of Scientific and Technical Information of China (English)

    Cheng-Bo Yu; Xiao-Ping Pan; Lan-Juan Li

    2009-01-01

    BACKGROUND: Bioartiifcial liver support systems are becoming an effective therapy for hepatic failure. Bioreactors, as key devices in these systems, can provide a favorable growth and metabolic environment, mass exchange, and immunological isolation as a platform. Currently, stagnancy in bioreactor research is the main factor restricting the development of bioartiifcial liver support systems. DATA SOURCES: A PubMed database search of English-language literature was performed to identify relevant articles using the keywords "bioreactor", "bioartiifcial liver", "hepatocyte", and "liver failure". More than 40 articles related to the bioreactors of bioartiifcial livers were reviewed. RESULTS: Some progress has been made in the improvement of structures, functions, and modiifed macromolecular materials related to bioreactors in recent years. The current data on the improvement of bioreactor conifgurations for bioartiifcial livers or on the potential of the use of certain scaffold materials in bioreactors, combined with the clinical efifcacy and safety evaluation of cultured hepatocytesin vitro, indicate that the AMC (Academic Medical Center) BAL bioreactor and MELS (modular extracorporeal liver support) BAL bioreactor system can partly replace the synthetic and metabolic functions of the liver in phaseⅠ clinical studies. In addition, it has been indicated that the microlfuidic PDMS (polydimethylsiloxane) bioreactor, or SlideBioreactor, and the microfabricated grooved bioreactor are appropriate for hepatocyte culture, which is also promising for bioartiifcial livers. Similarly, modiifed scaffolds can promote the adhesion, growth, and function of hepatocytes, and provide reliable materials for bioreactors.CONCLUSIONS: Bioreactors, as key devices in bioartiifcial livers, play an important role in the therapy for liver failure both now and in the future. Bioreactor conifgurations are indispensable for the development of bioartiifcial livers used for liver

  15. 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-b...

  16. Preliminary Study on Airlift Membran—Bioreactor

    Institute of Scientific and Technical Information of China (English)

    XUNong; XINGWeihong; 等

    2002-01-01

    A new type of membrane bioreactor named “airlift membrane-bioreactor”is discussed.For municipal wastewater reclamation,the preliminary study on airlift membrane-bioreactor shows its good performance such as high flux and lower energy consumption.The airlift membrane-bioreactor is potentially applicable in bioengineering and environmental protection fields.

  17. A framework for assessment and characterisation of municipal solid waste landfill leachate: an application to the Turbhe landfill, Navi Mumbai, India.

    Science.gov (United States)

    Mishra, Harshit; Rathod, Merwan; Karmakar, Subhankar; Kumar, Rakesh

    2016-06-01

    Rapid industrialisation, growing population and changing lifestyles are the root causes for the generation of huge amounts of solid waste in developing countries. In India, disposal of municipal solid waste (MSW) through open dumping is the most common waste disposal method. Unfortunately, leachate generation from landfill is high due to the prolonged and prominent monsoon season in India. As leachate generation rate is high in most of the tropical countries, long-term and extensive monitoring efforts are expected to evaluate actual environmental pollution potential due to leachate contamination. However, the leachate characterisation involves a comprehensive process, which has numerous shortcomings and uncertainties possibly due to the complex nature of landfilling process, heterogeneous waste characteristics, widely varying hydrologic conditions and selection of analytes. In order to develop a sustainable MSW management strategy for protecting the surface and ground water resources, particularly from MSW landfill leachate contamination, assessment and characterisation of leachate are necessary. Numerous studies have been conducted in the past to characterise leachate quality from various municipal landfills; unfortunately, none of these propose a framework or protocol. The present study proposes a generic framework for municipal landfill leachate assessment and characterisation. The proposed framework can be applied to design any type of landfill leachate quality monitoring programme and also to facilitate improved leachate treatment activities. A landfill site located at Turbhe, Navi Mumbai, India, which had not been investigated earlier, has been selected as a case study. The proposed framework has been demonstrated on the Turbhe landfill site which is a comparatively new and the only sanitary landfill in Navi Mumbai.

  18. Quantifying capital goods for waste landfilling

    DEFF Research Database (Denmark)

    Brogaard, Line Kai-Sørensen; Stentsøe, Steen; Willumsen, Hans Christian

    2013-01-01

    Materials and energy used for construction of a hill-type landfill of 4 million m3 were quantified in detail. The landfill is engineered with a liner and leachate collections system, as well as a gas collection and control system. Gravel and clay were the most common materials used, amounting...... to approximately 260 kg per tonne of waste landfilled. The environmental burdens from the extraction and manufacturing of the materials used in the landfill, as well as from the construction of the landfill, were modelled as potential environmental impacts. For example, the potential impact on global warming was 2.......5 kg carbon dioxide (CO2) equivalents or 0.32 milli person equivalents per tonne of waste. The potential impacts from the use of materials and construction of the landfill are low-to-insignificant compared with data reported in the literature on impact potentials of landfills in operation...

  19. Use of the landfill water pollution index (LWPI) for groundwater quality assessment near the landfill sites.

    Science.gov (United States)

    Talalaj, Izabela A; Biedka, Pawel

    2016-12-01

    The purpose of the paper is to assess the groundwater quality near the landfill sites using landfill water pollution index (LWPI). In order to investigate the scale of groundwater contamination, three landfills (E, H and S) in different stages of their operation were taken into analysis. Samples of groundwater in the vicinity of studied landfills were collected four times each year in the period from 2004 to 2014. A total of over 300 groundwater samples were analysed for pH, EC, PAH, TOC, Cr, Hg, Zn, Pb, Cd, Cu, as required by the UE legal acts for landfill monitoring system. The calculated values of the LWPI allowed the quantification of the overall water quality near the landfill sites. The obtained results indicated that the most negative impact on groundwater quality is observed near the old Landfill H. Improper location of piezometer at the Landfill S favoured infiltration of run-off from road pavement into the soil-water environment. Deep deposition of the groundwater level at Landfill S area reduced the landfill impact on the water quality. Conducted analyses revealed that the LWPI can be used for evaluation of water pollution near a landfill, for assessment of the variability of water pollution with time and for comparison of water quality from different piezometers, landfills or time periods. The applied WQI (Water Quality Index) can also be an important information tool for landfill policy makers and the public about the groundwater pollution threat from landfill.

  20. Development of thin-film photo-bioreactor and its application to outdoor culture of microalgae.

    Science.gov (United States)

    Yoo, Jae Jun; Choi, Seung Phill; Kim, Jaoon Y H; Chang, Won Seok; Sim, Sang Jun

    2013-06-01

    Photosynthetic microalgae have received much attention as a microbial source of diverse useful biomaterials through CO(2) fixation and various types of photo-bioreactors have been developed for efficient microalgal cultivation. Herein, we developed a novel thin-film photo-bioreactor, which was made of cast polypropylene film, considering outdoor mass cultivation. To develop optimal design of photo-bioreactor, we tested performance of three shapes of thin-film photo-bioreactors (flat, horizontal and vertical tubular shapes) and various parts in the bioreactor. Collectively, vertical tubular bioreactor with H/D ratio 6:1 and cylindrical stainless steel spargers showed the most outstanding performance. Furthermore, the photo-bioreactor was successfully applied to the cultivation of other microalgae such as Chlamydomonas reinhardtii and Chlorella vulgaris. The scalability of photo-bioreactor was confirmed by gradually increasing culture volume from 4 to 25 L and the biomass productivity of each reactor was quite consistent (0.05-0.07 g/L/day) during the cultivation of H. pluvialis under indoor and outdoor conditions. Especially, we also achieved dry cell weight of 4.64 g/L and astaxanthin yield of 218.16 mg/L through long-term cultivation (100 days) under outdoor condition in 15 L photo-bioreactor using Haematococcus pluvialis, which means that the astaxanthin yield from outdoor cultivation is equal or superior to that obtained from controlled indoor condition. Therefore, these results indicate that we can apply this approach to development of optimal photo-bioreactor for the large-scale culture of microalgae and production of useful biomaterials under outdoor condition.

  1. Tissue grown in NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    Cells from kidneys lose some of their special features in conventional culture but form spheres replete with specialized cell microvilli (hair) and synthesize hormones that may be clinically useful. Ground-based research studies have demonstrated that both normal and neoplastic cells and tissues recreate many of the characteristics in the NASA bioreactor that they display in vivo. Proximal kidney tubule cells that normally have rich apically oriented microvilli with intercellular clefts in the kidney do not form any of these structures in conventional two-dimensional monolayer culture. However, when normal proximal renal tubule cells are cultured in three-dimensions in the bioreactor, both the microvilli and the intercellular clefts form. This is important because, when the morphology is recreated, the function is more likely also to be rejuvenated. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC).

  2. Tissue grown in NASA Bioreactor

    Science.gov (United States)

    1998-01-01

    Cells from kidneys lose some of their special features in conventional culture but form spheres replete with specialized cell microvilli (hair) and synthesize hormones that may be clinically useful. Ground-based research studies have demonstrated that both normal and neoplastic cells and tissues recreate many of the characteristics in the NASA bioreactor that they display in vivo. Proximal kidney tubule cells that normally have rich apically oriented microvilli with intercellular clefts in the kidney do not form any of these structures in conventional two-dimensional monolayer culture. However, when normal proximal renal tubule cells are cultured in three-dimensions in the bioreactor, both the microvilli and the intercellular clefts form. This is important because, when the morphology is recreated, the function is more likely also to be rejuvenated. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC).

  3. The Use of Biofilter to Reduce Atmospheric Global Warming Gas (CH4) Eemissions from Landfills

    Science.gov (United States)

    Park, S.; Thomas, J. C.; Brown, K. W.; Sung, K.

    2001-12-01

    The emission of greenhouse gasses resulting from anthropogenic activities is increasing the atmospheric concentration of these gases, which can influence the climatic system by changing the temperature, precipitation, wind and other climate factors. Methane (CH4) is a very potent greenhouse gas and CH4 emission from landfills in US has been reported as 37% of total anthropogenic source of CH4 emission. Properly designed soil biofilters may reduce atmospheric CH4 emissions from landfills and help reduce the accumulation of greenhouse gasses in the atmosphere. Biofilter performance was tested under a variety of environmental and design conditions. The results showed that biofilters have the potential to reduce CH4 emissions from landfills by as much as 83%. A quadratic equation was developed to describe the dependence of methane oxidation rate in a sandy loam textured soil as a function of soil temperature, soil moisture and ammonium nitrogen concentration. Using this equation and the averaged soil temperature and moisture contents, and census data for the largest cities of each of the 48 contiguous states, oxidation rates was calculated. A methane emission model was also developed to estimate the methane emission from municipal waste landfills with different covers. Older landfills with soil covers emitted an average of 83% of the generated CH4. Landfills with RCRA covers emitted 90% of the generated CH4 without biofilters and only 10% with biofilters. Thus, the installation of properly sized biofilters should significantly reduce atmospheric CH4 emissions from landfills.

  4. Optimal Homogenization of Perfusion Flows in Microfluidic Bio-Reactors: A Numerical Study

    DEFF Research Database (Denmark)

    Okkels, Fridolin; Dufva, Martin; Bruus, Henrik

    2011-01-01

    In recent years, the interest in small-scale bio-reactors has increased dramatically. To ensure homogeneous conditions within the complete area of perfused microfluidic bio-reactors, we develop a general design of a continually feed bio-reactor with uniform perfusion flow. This is achieved...... by introducing a specific type of perfusion inlet to the reaction area. The geometry of these inlets are found using the methods of topology optimization and shape optimization. The results are compared with two different analytic models, from which a general parametric description of the design is obtained...... and tested numerically. Such a parametric description will generally be beneficial for the design of a broad range of microfluidic bioreactors used for, e. g., cell culturing and analysis and in feeding bio-arrays....

  5. Greenhouse gas emissions from landfill leachate treatment plants: A comparison of young and aged landfill

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojun, E-mail: xjwang@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Jia, Mingsheng, E-mail: msjia@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Chen, Xiaohai, E-mail: cxiaoh_xm@126.com [Xiamen City Environmental Sanitation Management Department, Xiamen 361000 (China); Xu, Ying, E-mail: yxu@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Lin, Xiangyu, E-mail: xylin@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Kao, Chih Ming, E-mail: jkao@mail.nsysu.edu.tw [Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Chen, Shaohua, E-mail: shchen@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China)

    2014-07-15

    Highlights: • Young and aged leachate works accounted for 89.1% and 10.9% of 33.35 Gg CO{sub 2} yr{sup −1}. • Fresh leachate owned extremely low ORP and high organic matter content. • Strong CH{sub 4} emissions occurred in the fresh leachate ponds, but small in the aged. • N{sub 2}O emissions became dominant in the treatment units of both systems. • 8.45–11.9% of nitrogen was removed as the form of N{sub 2}O under steady-state. - Abstract: With limited assessment, leachate treatment of a specified landfill is considered to be a significant source of greenhouse gas (GHG) emissions. In our study, the cumulative GHG emitted from the storage ponds and process configurations that manage fresh or aged landfill leachate were investigated. Our results showed that strong CH{sub 4} emissions were observed from the fresh leachate storage pond, with the fluxes values (2219–26,489 mg C m{sup −2} h{sup −1}) extremely higher than those of N{sub 2}O (0.028–0.41 mg N m{sup −2} h{sup −1}). In contrast, the emission values for both CH{sub 4} and N{sub 2}O were low for the aged leachate tank. N{sub 2}O emissions became dominant once the leachate entered the treatment plants of both systems, accounting for 8–12% of the removal of N-species gases. Per capita, the N{sub 2}O emission based on both leachate treatment systems was estimated to be 7.99 g N{sub 2}O–N capita{sup −1} yr{sup −1}. An increase of 80% in N{sub 2}O emissions was observed when the bioreactor pH decreased by approximately 1 pH unit. The vast majority of carbon was removed in the form of CO{sub 2}, with a small portion as CH{sub 4} (<0.3%) during both treatment processes. The cumulative GHG emissions for fresh leachate storage ponds, fresh leachate treatment system and aged leachate treatment system were 19.10, 10.62 and 3.63 Gg CO{sub 2} eq yr{sup −1}, respectively, for a total that could be transformed to 9.09 kg CO{sub 2} eq capita{sup −1} yr{sup −1}.

  6. Detection of contaminant plumes released from landfills

    Science.gov (United States)

    Yenigül, N. B.; Hendsbergen, A. T.; Elfeki, A. M. M.; Dekking, F. M.

    2006-06-01

    Contaminant leaks released from landfills are a significant threat to groundwater quality. The groundwater detection monitoring systems installed in the vicinity of such facilities are vital. In this study the detection probability of a contaminant plume released from a landfill has been investigated by means of both a simulation and an analytical model for both homogeneous and heterogeneous aquifer conditions. The results of the two models are compared for homogeneous aquifer conditions to illustrate the errors that might be encountered with the simulation model. For heterogeneous aquifer conditions contaminant transport is modelled by an analytical model using effective (macro) dispersivities. The results of the analysis show that the simulation model gives the concentration values correctly over most of the plume length for homogeneous aquifer conditions, and that the detection probability of a contaminant plume at given monitoring well locations match quite well. For heterogeneous aquifer conditions the approximating analytical model based on effective (macro) dispersivities yields the average concentration distribution satisfactorily. However, it is insufficient in monitoring system design since the discrepancy between the detection probabilities of contaminant plumes at given monitoring well locations computed by the two models is significant, particularly with high dispersivity and heterogeneity.

  7. SEISMIC DISTRESS AND PROTECTION OF FLEXIBLE MEMBRANE LINERS OF SOLID WASTE LANDFILLS

    DEFF Research Database (Denmark)

    Zania, Varvara; Tsompanakis, Yiannis; Psarropoulos, Prodromos

    2011-01-01

    Seismic distress of solid waste landfills may result from any of the two consequences of a seismic event: (a) the transient ground deformation related to seismic wave propagation, (b) the permanent ground deformation caused by abrupt fault dislocation. Design provisions for solid waste landfills......-element analyses were performed, taking also into account the potential slip displacement development along the interfaces formulated on each side of the flexible membrane liner (FML). It is shown that base fault dislocation causes significant plastic strains at each one of the components of the waste landfill...

  8. Use Alkalinity Monitoring to Optimize Bioreactor Performance.

    Science.gov (United States)

    Jones, Christopher S; Kult, Keegan J

    2016-05-01

    In recent years, the agricultural community has reduced flow of nitrogen from farmed landscapes to stream networks through the use of woodchip denitrification bioreactors. Although deployment of this practice is becoming more common to treat high-nitrate water from agricultural drainage pipes, information about bioreactor management strategies is sparse. This study focuses on the use of water monitoring, and especially the use of alkalinity monitoring, in five Iowa woodchip bioreactors to provide insights into and to help manage bioreactor chemistry in ways that will produce desirable outcomes. Results reported here for the five bioreactors show average annual nitrate load reductions between 50 and 80%, which is acceptable according to established practice standards. Alkalinity data, however, imply that nitrous oxide formation may have regularly occurred in at least three of the bioreactors that are considered to be closed systems. Nitrous oxide measurements of influent and effluent water provide evidence that alkalinity may be an important indicator of bioreactor performance. Bioreactor chemistry can be managed by manipulation of water throughput in ways that produce adequate nitrate removal while preventing undesirable side effects. We conclude that (i) water should be retained for longer periods of time in bioreactors where nitrous oxide formation is indicated, (ii) measuring only nitrate and sulfate concentrations is insufficient for proper bioreactor operation, and (iii) alkalinity monitoring should be implemented into protocols for bioreactor management.

  9. Imaging and characterization of heterogeneous landfills using geophysical methods

    NARCIS (Netherlands)

    Konstantaki, L.A.

    2016-01-01

    Nowadays many countries use landfilling for the management of their waste or for treating old landfills. Emissions from landfills can be harmful to the environment and to human health, making the stabilization of landfills a priority for the landfill communities. Estimation of the emission potential

  10. Imaging and characterization of heterogeneous landfills using geophysical methods

    NARCIS (Netherlands)

    Konstantaki, L.A.

    2016-01-01

    Nowadays many countries use landfilling for the management of their waste or for treating old landfills. Emissions from landfills can be harmful to the environment and to human health, making the stabilization of landfills a priority for the landfill communities. Estimation of the emission potential

  11. Environmental Control in Flow Bioreactors

    Directory of Open Access Journals (Sweden)

    Serena Giusti

    2017-04-01

    Full Text Available The realization of physiologically-relevant advanced in vitro models is not just related to the reproduction of a three-dimensional multicellular architecture, but also to the maintenance of a cell culture environment in which parameters, such as temperature, pH, and hydrostatic pressure are finely controlled. Tunable and reproducible culture conditions are crucial for the study of environment-sensitive cells, and can also be used for mimicking pathophysiological conditions related with alterations of temperature, pressure and pH. Here, we present the SUITE (Supervising Unit for In Vitro Testing system, a platform able to monitor and adjust local environmental variables in dynamic cell culture experiments. The physical core of the control system is a mixing chamber, which can be connected to different bioreactors and acts as a media reservoir equipped with a pH meter and pressure sensors. The chamber is heated by external resistive elements and the temperature is controlled using a thermistor. A purpose-built electronic control unit gathers all data from the sensors and controls the pH and hydrostatic pressure by regulating air and CO2 overpressure and flux. The system’s modularity and the possibility of imposing different pressure conditions were used to implement a model of portal hypertension with both endothelial and hepatic cells. The results show that the SUITE platform is able to control and maintain cell culture parameters at fixed values that represent either physiological or pathological conditions. Thus, it represents a fundamental tool for the design of biomimetic in vitro models, with applications in disease modelling or toxicity testing.

  12. Tissue engineering bioreactor systems for applying physical and electrical stimulations to cells.

    Science.gov (United States)

    Jin, GyuHyun; Yang, Gi-Hoon; Kim, GeunHyung

    2015-05-01

    Bioreactor systems in tissue engineering applications provide various types of stimulation to mimic the tissues in vitro and in vivo. Various bioreactors have been designed to induce high cellular activities, including initial cell attachment, cell growth, and differentiation. Although cell-stimulation processes exert mostly positive effects on cellular responses, in some cases such stimulation can also have a negative effect on cultured cells. In this review, we discuss various types of bioreactor and the positive and negative effects of stimulation (physical, chemical, and electrical) on various cultured cell types.

  13. Spaceflight bioreactor studies of cells and tissues.

    Science.gov (United States)

    Freed, Lisa E; Vunjak-Novakovic, Gordana

    2002-01-01

    Studies of the fundamental role of gravity in the development and function of biological organisms are a central component of the human exploration of space. Microgravity affects numerous physical phenomena relevant to biological research, including the hydrostatic pressure in fluid filled vesicles, sedimentation of organelles, and buoyancy-driven convection of flow and heat. These physical phenomena can in turn directly and indirectly affect cellular morphology, metabolism, locomotion, secretion of extracellular matrix and soluble signals, and assembly into functional tissues. Studies aimed at distinguishing specific effects of gravity on biological systems require the ability to: (i) control and systematically vary gravity, e.g. by utilizing the microgravity environment of space in conjunction with an in-flight centrifuge; and (ii) maintain constant all other factors in the immediate environment, including in particular concentrations and exchange rates of biochemical species and hydrodynamic shear. The latter criteria imply the need for gravity-independent mechanisms to provide for mass transport between the cells and their environment. Available flight hardware has largely determined the experimental design and scientific objectives of spaceflight cell and tissue culture studies carried out to date. Simple culture vessels have yielded important quantitative data, and helped establish in vitro models of cell locomotion, growth and differentiation in various mammalian cell types including embryonic lung cells [6], lymphocytes [2,8], and renal cells [7,31]. Studies done using bacterial cells established the first correlations between gravity-dependent factors such as cell settling velocity and diffusional distance and the respective cell responses [12]. The development of advanced bioreactors for microgravity cell and tissue culture and for tissue engineering has benefited both research areas and provided relevant in vitro model systems for studies of astronaut

  14. Effect of enzyme additions on methane production and lignin degradation of landfilled sample of municipal solid waste.

    Science.gov (United States)

    Jayasinghe, P A; Hettiaratchi, J P A; Mehrotra, A K; Kumar, Sunil

    2011-04-01

    Operation of waste cells as landfill bioreactors with leachate recirculation is known to accelerate waste degradation and landfill gas generation. However, waste degradation rates in landfill bioreactors decrease with time, with the accumulation of difficult to degrade materials, such as lignin-rich waste. Although, potential exists to modify the leachate quality to promote further degradation of such waste, very little information is available in literature. The objective of this study was to determine the viability of augmenting leachate with enzymes to increase the rate of degradation of lignin-rich waste materials. Among the enzymes evaluated MnP enzyme showed the best performance in terms of methane yield and substrate (lignin) utilization. Methane production of 200 mL CH(4)/g VS was observed for the MnP amended reactor as compared to 5.7 mL CH(4)/g VS for the control reactor. The lignin reduction in the MnP amended reactor and control reactor was 68.4% and 6.2%, respectively.

  15. Two new disposable bioreactors for plant cell culture: The wave and undertow bioreactor and the slug bubble bioreactor.

    Science.gov (United States)

    Terrier, Bénédicte; Courtois, Didier; Hénault, Nicolas; Cuvier, Arnaud; Bastin, Maryse; Aknin, Aziz; Dubreuil, Julien; Pétiard, Vincent

    2007-04-01

    The present article describes two novel flexible plastic-based disposable bioreactors. The first one, the WU bioreactor, is based on the principle of a wave and undertow mechanism that provides agitation while offering convenient mixing and aeration to the plant cell culture contained within the bioreactor. The second one is a high aspect ratio bubble column bioreactor, where agitation and aeration are achieved through the intermittent generation of large diameter bubbles, "Taylor-like" or "slug bubbles" (SB bioreactor). It allows an easy volume increase from a few liters to larger volumes up to several hundred liters with the use of multiple units. The cultivation of tobacco and soya cells producing isoflavones is described up to 70 and 100 L working volume for the SB bioreactor and WU bioreactor, respectively. The bioreactors being disposable and pre-sterilized before use, cleaning, sterilization, and maintenance operations are strongly reduced or eliminated. Both bioreactors represent efficient and low cost cell culture systems, applicable to various cell cultures at small and medium scale, complementary to traditional stainless-steel bioreactors.

  16. Evaluation and selection of decision-making methods to assess landfill mining projects.

    Science.gov (United States)

    Hermann, Robert; Baumgartner, Rupert J; Vorbach, Stefan; Ragossnig, Arne; Pomberger, Roland

    2015-09-01

    For the first time in Austria, fundamental technological and economic studies on recovering secondary raw materials from large landfills have been carried out, based on the 'LAMIS - Landfill Mining Austria' pilot project. A main focus of the research - and the subject of this article - was to develop an assessment or decision-making procedure that allows landfill owners to thoroughly examine the feasibility of a landfill mining project in advance. Currently there are no standard procedures that would sufficiently cover all the multiple-criteria requirements. The basic structure of the multiple attribute decision making process was used to narrow down on selection, conceptual design and assessment of suitable procedures. Along with a breakdown into preliminary and main assessment, the entire foundation required was created, such as definitions of requirements to an assessment method, selection and accurate description of the various assessment criteria and classification of the target system for the present 'landfill mining' vs. 'retaining the landfill in after-care' decision-making problem. Based on these studies, cost-utility analysis and the analytical-hierarchy process were selected from the range of multiple attribute decision-making procedures and examined in detail. Overall, both methods have their pros and cons with regard to their use for assessing landfill mining projects. Merging these methods or connecting them with single-criteria decision-making methods (like the net present value method) may turn out to be reasonable and constitute an appropriate assessment method.

  17. IJER@2014 Page 57 Disposal Criteria of Bhanpur Solid Waste Landfill Site: Investigation and Suggestions

    Directory of Open Access Journals (Sweden)

    Tapas Dasgpta

    2014-03-01

    Full Text Available The solid waste management and design assist waste management officials in developing and encouraging environmentally sound methods for the disposal of "nonhazardous" solid waste. Promulgated under the authority of municipal act, the Municipal Solid Waste Landfill (MSWLF regulation act establish a framework for planning and implementing municipal solid waste landfill programs at the state and local levels. This framework sets minimum standards for protecting human health and the environment, while allowing states to develop more flexible MSWLF criteria. Intension to mitigate or expeditiously remediate potential adverse environmental impacts resulting from municipal landfills. However, other regulations existed prior to the revised MSWLF standards discussed in this module. The promulgation Criteria for Classification of Solid Waste Disposal Facilities and Practices. The established regulatory standards to satisfy the minimum national performance criteria for sanitary landfills governs only those solid waste disposal facilities and practices that do not meet the definition of a MSWLF. Such facilities include waste piles, industrial nonhazardous waste landfills, surface impoundments, and land application units. Environmental Protect Authority (EPA modified address the fact that these non-municipal non-hazardous wastes landfills may receive Conditionally Exempt Small Quantity Generator (CESQG hazardous waste, further clarify that construction and demolition landfills may receive residential lead-based paint waste as Solid Waste Disposal Facilities without for MSWLFs as long as all conditions are met.

  18. Solid waste management in Croatia in response to the European Landfill Directive.

    Science.gov (United States)

    Stanic-Maruna, Ira; Fellner, Johann

    2012-08-01

    The European Landfill Directive 99/31/EC represents the most influential piece of waste legislation on the management of municipal solid waste. In addition to technical standards regarding the design and location of landfills, it calls for a decrease in the amount of biodegradable waste landfilled. In order to meet the reduction targets set in the Landfill Directive, national solid waste strategies need to be changed. This article outlines the impact of the Landfill Directive on the Croatian waste management strategy and discusses the key challenges of its implementation. In addition, three scenarios of future waste management (mechanical biological pre-treatment, waste-to-energy and landfilling) have been investigated and evaluated regarding environmental impacts and affordability. The results of the analysis show that Croatia has transposed the said Directive into its own legislation in an exemplary way. The developed national waste management strategy foresees the set up of a separate collection of recyclables, waste pre-treatment of MSW, as well as the upgrading of existing disposal sites to sanitary landfills. However, the practical progress of carrying out provisions implemented on paper is lagging behind. Concerning the investigated scenarios the results of the evaluation indicate that mechanical biological pre-treatment in conjunction with separate collection of recyclables appears to be the most feasible option (in terms of economic and ecologic parameters). This result is in line with the proposed national waste management strategy.

  19. Alleviating liver failure conditions using an integrated hybrid cryogel based cellular bioreactor as a bioartificial liver support

    Science.gov (United States)

    Damania, Apeksha; Hassan, Mohsin; Shirakigawa, Nana; Mizumoto, Hiroshi; Kumar, Anupam; Sarin, Shiv K.; Ijima, Hiroyuki; Kamihira, Masamichi; Kumar, Ashok

    2017-01-01

    Conventionally, some bioartificial liver devices are used with separate plasmapheresis unit to separate out plasma from whole blood and adsorbent column to detoxify plasma before it passes through a hepatocytes-laden bioreactor. We aim to develop a hybrid bioreactor that integrates the separate modules in one compact design improving the efficacy of the cryogel based bioreactor as a bioartificial liver support. A plasma separation membrane and an activated carbon cloth are placed over a HepG2-loaded cryogel scaffold in a three-chambered bioreactor design. This bioreactor is consequently connected extracorporeally to a rat model of acute liver failure for 3 h and major biochemical parameters studied. Bilirubin and aspartate transaminase showed a percentage decrease of 20–60% in the integrated bioreactor as opposed to 5–15% in the conventional setup. Urea and ammonia levels which showed negligible change in the conventional setup increase (40%) and decrease (18%), respectively in the integrated system. Also, an overall increase of 5% in human albumin in rat plasma indicated bioreactor functionality in terms of synthetic functions. These results were corroborated by offline evaluation of patient plasma. Hence, integrating the plasmapheresis and adsorbent units with the bioreactor module in one compact design improves the efficacy of the bioartificial liver device. PMID:28079174

  20. Landfill reduction experience in The Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Scharff, Heijo, E-mail: h.scharff@afvalzorg.nl

    2014-11-15

    Highlights: • ‘Zero waste’ initiatives never consider risks, side effects or experience of achieved low levels of landfill. • This paper provides insight into what works and what not. • Where strong gradients in regulations and tax occur between countries, waste will find its way to landfills across borders. • Strong landfill reduction can create a fierce competition over the remaining waste to be landfilled resulting in losses. • At some point a public organisation should take responsibility for the operation of a ‘safety net’ in waste management. - Abstract: Modern waste legislation aims at resource efficiency and landfill reduction. This paper analyses more than 20 years of landfill reduction in the Netherlands. The combination of landfill regulations, landfill tax and landfill bans resulted in the desired landfill reduction, but also had negative effects. A fierce competition developed over the remaining waste to be landfilled. In 2013 the Dutch landfill industry generated €40 million of annual revenue, had €58 million annual costs and therefore incurred an annual loss of €18 million. It is not an attractive option to prematurely end business. There is a risk that Dutch landfill operators will not be able to fulfil the financial obligations for closure and aftercare. Contrary to the polluter pays principle the burden may end up with society. EU regulations prohibiting export of waste for disposal are in place. Strong differentials in landfill tax rate between nations have nevertheless resulted in transboundary shipment of waste and in non-compliance with the self-sufficiency and proximity principles. During the transformation from a disposal society to a recycling society, it is important to carefully plan required capacity and to guide the reorganisation of the landfill sector. At some point, it is no longer profitable to provide landfill services. It may be necessary for public organisations or the state to take responsibility for the

  1. Novel Hydrogen Bioreactor and Detection Apparatus.

    Science.gov (United States)

    Rollin, Joseph A; Ye, Xinhao; Del Campo, Julia Martin; Adams, Michael W W; Zhang, Y-H Percival

    2016-01-01

    In vitro hydrogen generation represents a clear opportunity for novel bioreactor and system design. Hydrogen, already a globally important commodity chemical, has the potential to become the dominant transportation fuel of the future. Technologies such as in vitro synthetic pathway biotransformation (SyPaB)-the use of more than 10 purified enzymes to catalyze unnatural catabolic pathways-enable the storage of hydrogen in the form of carbohydrates. Biohydrogen production from local carbohydrate resources offers a solution to the most pressing challenges to vehicular and bioenergy uses: small-size distributed production, minimization of CO2 emissions, and potential low cost, driven by high yield and volumetric productivity. In this study, we introduce a novel bioreactor that provides the oxygen-free gas phase necessary for enzymatic hydrogen generation while regulating temperature and reactor volume. A variety of techniques are currently used for laboratory detection of biohydrogen, but the most information is provided by a continuous low-cost hydrogen sensor. Most such systems currently use electrolysis for calibration; here an alternative method, flow calibration, is introduced. This system is further demonstrated here with the conversion of glucose to hydrogen at a high rate, and the production of hydrogen from glucose 6-phosphate at a greatly increased reaction rate, 157 mmol/L/h at 60 °C.

  2. LTCC based bioreactors for cell cultivation

    Science.gov (United States)

    Bartsch, H.; Welker, T.; Welker, K.; Witte, H.; Müller, J.

    2016-01-01

    LTCC multilayers offer a wide range of structural options and flexibility of connections not available in standard thin film technology. Therefore they are considered as material base for cell culture reactors. The integration of microfluidic handling systems and features for optical and electrical capturing of indicators for cell culture growth offers the platform for an open system concept. The present paper assesses different approaches for the creation of microfluidic channels in LTCC multilayers. Basic functions required for the fluid management in bioreactors include temperature and flow control. Both features can be realized with integrated heaters and temperature sensors in LTCC multilayers. Technological conditions for the integration of such elements into bioreactors are analysed. The temperature regulation for the system makes use of NTC thermistor sensors which serve as real value input for the control of the heater. It allows the adjustment of the fluid temperature with an accuracy of 0.2 K. The tempered fluid flows through the cell culture chamber. Inside of this chamber a thick film electrode array monitors the impedance as an indicator for the growth process of 3-dimensional cell cultures. At the system output a flow sensor is arranged to monitor the continual flow. For this purpose a calorimetric sensor is implemented, and its crucial design parameters are discussed. Thus, the work presented gives an overview on the current status of LTCC based fluid management for cell culture reactors, which provides a promising base for the automation of cell culture processes.

  3. Y-12 Industrial Landfill V. Permit application modifications

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This report contains the modifications in operations and design to meet the Tennessee Department of Environment and Conversation (TDEC) July 10, 1993, amendments to the regulations for Class 2 landfills. These modifications, though extensive in design and construction cost, are considered minor revisions and should not require a processing fee. Area 1 of ILF V, comprising approximately 20% of the ILF V footprint, was designed and submitted to TDEC prior to the implementation of current regulations. This initial area was constructed with a compacted clay liner and leachate collection system, and became operational in April 1994. The current regulations require landfills to have a composite liner with leachate collection system and closure cap. Modifications to upgrade Areas 2 and 3 of ILF V to meet the current TDEC requirements are included.

  4. Use of a Three-Dimensional Reactive Solute Transport Model for Evaluation of Bioreactor Placement in Stream Restoration.

    Science.gov (United States)

    Cui, Zhengtao; Welty, Claire; Gold, Arthur J; Groffman, Peter M; Kaushal, Sujay S; Miller, Andrew J

    2016-05-01

    A three-dimensional groundwater flow and multispecies reactive transport model was used to strategically design placement of bioreactors in the subsurface to achieve maximum removal of nitrate along restored stream reaches. Two hypothetical stream restoration scenarios were evaluated over stream reaches of 40 and 94 m: a step-pool scenario and a channel re-meandering scenario. For the step-pool scenario, bioreactors were placed at locations where mass fluxes of groundwater and nitrate were highest. Bioreactors installed over 50% of the total channel length of a step-pool scenario (located to intercept maximum groundwater and nitrate mass flux) removed nitrate-N entering the channel at a rate of 36.5 kg N yr (100 g N d), achieving about 65% of the removal of a whole-length bioreactor. Bioreactor placement for the re-meandering scenario was designed using a criterion of either highest nitrate mass flux or highest groundwater flux, but not both, because they did not occur together. Bioreactors installed at maximum nitrate flux locations (53% of the total channel length) on the western bank removed nitrate-N entering the channel at 62.0 kg N yr (170 g N d), achieving 85% of nitrate-N removal of whole-length bioreactors for the re-meandering scenario. Bioreactors installed at maximum groundwater flux locations on the western bank along approximately 40% of the re-meandering channel achieved about 65% of nitrate removal of whole-length bioreactors. Placing bioreactors at maximum nitrate flux locations improved denitrification efficiency. Due to low groundwater velocities, bioreactor nitrate-N removal was found to be nitrate limited for all scenarios.

  5. Quantification of methane emissions from danish landfills

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Mønster, Jacob; Kjeldsen, Peter

    2013-01-01

    Whole-landfill methane emission was quantified using a tracer technique that combines controlled tracer gas release from the landfill with time-resolved concentration measurements downwind of the landfill using a mobile high-resolution analytical instrument. Methane emissions from 13 Danish...... landfills varied between 2.6 and 60.8 kg CH4 h–1. The highest methane emission was measured at the largest (in terms of disposed waste amounts) of the 13 landfills, whereas the lowest methane emissions (2.6-6.1 kgCH4 h–1) were measured at the older and smaller landfills. At two of the sites, which had gas...... collection, emission measurements showed that the gas collection systems only collected between 30-50% of the methane produced (assuming that the produced methane equalled the sum of the emitted methane and the collected methane). Significant methane emissions were observed from disposed shredder waste...

  6. Landfilling: Bottom Lining and Leachate Collection

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Manfredi, Simone; Kjeldsen, Peter

    2011-01-01

    from entering the groundwater or surface water. The bottom lining system should cover the full footprint area of the landfill, including both the relatively flat bottom and the sideslopes in the case of an excavated configuration. This prevents the lateral migration of leachate from within the landfill...... triple) liners, are extremely effective in preventing leachate from entering into the environment. In addition, the risk of polluting the groundwater at a landfill by any leakage of leachate depends on several factors related to siting of the landfill: distance to the water table, distance to surface...... water bodies, and the properties of the soil beneath the landfill. In addition to the lining and drainage systems described in this chapter, the siting and hydrogeology of the landfill site (Chapter 10.12) and the top cover (Chapter 10.9) are also part of the barrier system, contributing to reducing...

  7. Vertical alignment design of a landfill approaching road%垃圾处理场进场道路纵断面线形设计

    Institute of Scientific and Technical Information of China (English)

    陈玖玲; 杨鎏; 沈家旺

    2016-01-01

    The finite element amendment model is established to get the pulling slope vertical curve and vertical section view with Haiti road design software.The design of approaching road vertical section is evaluated with the model and the results show that the road design is based on the earth-rock and meets the needs of both construction and driving.%利用海地道路设计软件进行有限元建模修正,拉坡设竖曲线,得到纵断面图。根据建模得到的设计图对进场道路纵断面的设计进行评价。结果表明,该设计合理利用了土石方,满足施工需要和汽车行驶要求。

  8. LANDFILL LEACHATES PRETREATMENT BY OZONATION

    Directory of Open Access Journals (Sweden)

    Jacek Leszczyński

    2016-06-01

    Full Text Available In this paper, the application of ozonation processes for stabilized landfill leachate treatment was investigated. The leachate came from a municipal sanitary landfill located nearby Bielsk Podlaski. The average values of its main parameters were: pH 8.23; COD 870 mgO2/dm3; BOD 90 mgO2/dm3; NH4+ 136.2 mgN/dm3; UV254 absorbance 0.312 and turbidity 14 NTU. The ozone dosages used were in the range of 115.5 to 808.5 mgO3/dm3 of the leachate. The maximum COD, color and UV254 absorbance removal wa.5 mgO3/dm3. After oxidation, the ratio of BOD/COD was increased from 0.1 up to 0.23.

  9. Estimating methane emissions from landfills based on rainfall, ambient temperature, and waste composition: The CLEEN model.

    Science.gov (United States)

    Karanjekar, Richa V; Bhatt, Arpita; Altouqui, Said; Jangikhatoonabad, Neda; Durai, Vennila; Sattler, Melanie L; Hossain, M D Sahadat; Chen, Victoria

    2015-12-01

    Accurately estimating landfill methane emissions is important for quantifying a landfill's greenhouse gas emissions and power generation potential. Current models, including LandGEM and IPCC, often greatly simplify treatment of factors like rainfall and ambient temperature, which can substantially impact gas production. The newly developed Capturing Landfill Emissions for Energy Needs (CLEEN) model aims to improve landfill methane generation estimates, but still require inputs that are fairly easy to obtain: waste composition, annual rainfall, and ambient temperature. To develop the model, methane generation was measured from 27 laboratory scale landfill reactors, with varying waste compositions (ranging from 0% to 100%); average rainfall rates of 2, 6, and 12 mm/day; and temperatures of 20, 30, and 37°C, according to a statistical experimental design. Refuse components considered were the major biodegradable wastes, food, paper, yard/wood, and textile, as well as inert inorganic waste. Based on the data collected, a multiple linear regression equation (R(2)=0.75) was developed to predict first-order methane generation rate constant values k as functions of waste composition, annual rainfall, and temperature. Because, laboratory methane generation rates exceed field rates, a second scale-up regression equation for k was developed using actual gas-recovery data from 11 landfills in high-income countries with conventional operation. The Capturing Landfill Emissions for Energy Needs (CLEEN) model was developed by incorporating both regression equations into the first-order decay based model for estimating methane generation rates from landfills. CLEEN model values were compared to actual field data from 6 US landfills, and to estimates from LandGEM and IPCC. For 4 of the 6 cases, CLEEN model estimates were the closest to actual.

  10. Evaluation of an Odour Emission Factor (OEF) to estimate odour emissions from landfill surfaces

    Science.gov (United States)

    Lucernoni, Federico; Tapparo, Federica; Capelli, Laura; Sironi, Selena

    2016-11-01

    Emission factors are fundamental tools for air quality management. Odour Emission Factors (OEFs) can be developed in analogy with the emission factors defined for other chemical compounds, which relate the quantity of a pollutant released to the atmosphere to a given associated activity. Landfills typically represent a common source of odour complaint; for this reason, the development of specific OEFs allowing the estimation of odour emissions from this kind of source would be of great interest both for the landfill design and management. This study proposes an up-to-date methodology for the development of an OEF for the estimation of odour emissions from landfills, thereby focusing on the odour emissions related to the emissions of landfill gas (LFG) from the exhausted landfill surface. The proposed approach is an "indirect" approach based on the quantification of the LFG emissions from methane concentration measurements carried out on an Italian landfill. The Odour Emission Rate (OER) is then obtained by multiplying the emitted gas flow rate by the LFG odour concentration. The odour concentration of the LFG emitted through the landfill surface was estimated by means of an ad hoc correlation investigated between methane concentration and odour concentration. The OEF for the estimation of odour emissions from landfill surfaces was computed, considering the landfill surface as the activity index, as the product between the mean specific LFG flux emitted through the surface resulting from the experimental campaigns, equal to 0.39 l/m2/h, and its odour concentration, which was estimated to be equal to 105‧000 eq. ouE/m3, thus giving an OEF of 0.011 ouE/m2/s. This value, which is considerably lower than those published in previous works, should be considered as an improved estimation based on the most recent developments of the research in the field of odour sampling on surface sources.

  11. Estimating methane gas generation from Devil's swamp landfill using greenhouse gas emission models

    Science.gov (United States)

    Adeyemi, Ayodeji Thompson

    Greenhouse gas (GHG) has been a key issue in the study, design, and management of landfills. Landfill gas (LFG) is considered either as a significant source of renewable energy (if extracted and processed accordingly) or significant source of pollution and risk (if not mitigated or processed). A municipal solid waste (MSW) landfill emits a significant amount of methane, a potent GHG. Thus, quantification and mitigation of GHG emissions is an important area of study in engineering and other sciences related to landfill technology and management. The present study will focus on estimating methane generation from Devils swamp landfill (DSLF), a closed landfill in Baton Rouge, LA. The landfill operated for 53 years (1940-1993) and contains both industrial and municipal waste products. Since the Clean Air Act of 1963, landfills are now classified as New Source Performance Standard (NSPS) waste (i.e., waste that will decompose to generate LFG). Currently, the DSLF is being used as source of renewable energy through the "Waste to Energy" program. For this study, to estimate the methane potential in the DSLF, it is important to determine the characteristics and classification of the landfill's wastes. The study uses and compares different GHG modeling tools---LandGEM, a multiphase model, and a simple first-order model---to estimate methane gas emission and compare results with the actual emissions from the DSLF. The sensitivity of the methane generation rate was analyzed by the methane generation models to assess the effects of variables such as initial conditions, specific growth rate, and reaction rate constants. The study concludes that methane (L0) and initial organic concentration in waste (k) are the most important parameters when estimating methane generation using the models.

  12. Limited site investigation of Landfills 1 and 4, Fort Lewis, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Last, G.V.; Eddy, P.A.; Airhart, S.P.; Olsen, K.R.; Raymond, J.R.; Dahl, D.R.

    1990-08-01

    The information presented in this report was collected during limited site investigation activities conducted in the vicinity of Landfills 1 and 4 at Fort Lewis. The purpose of this work was to provide a means of detecting and evaluating the impacts of these inactive landfills on ground-water quality and adjacent lands. This effort included the design and construction of ground-water monitoring systems for compliance with applicable federal and state regulations governing Resource Conservation and Recovery Act (RCRA)-type landfills. Ground-water samples were collected from both existing (1981 and 1984) wells and the newly installed (1988) wells. The analytical results from the water samples indicate that the ground water in and around Landfill 1 contains limited contamination. Contaminants may include volatile organic compounds and nitrate. The primary concern in the area around Landfill 1 was the determination that ground water from two wells may contain cis-1,2-dichloroethylene and 1,1,1-trichloroethylene above drinking water standards. Nitrate levels in the downgradient wells were greater than those in upgradient wells and exceeded drinking water standards in some of the less-representative samples. Analyses of ground-water samples from wells in and around Landfill 4 indicate several contaminants may be present. These include volatile organic compounds (principally cis-1,2-dichloroethylene and 1,1,1-trichloroethylene), coliform, oil and grease, and perhaps some metals (iron and magnesium). The primary concern in the area around Landfill 4 was the determination that ground water from five wells contained cis-1,2-dichloroethylene and 1,1,1-trichloroethylene above drinking water standards. The source of contaminants beneath either landfill cannot yet be identified. Insufficient data exist to disprove or confirm either landfill as possible contributors. 19 refs., 32 figs., 17 tabs.

  13. Congenital anomalies and proximity to landfill sites.

    LENUS (Irish Health Repository)

    Boyle, E

    2004-01-01

    The occurrence of congenital anomalies in proximity to municipal landfill sites in the Eastern Region (counties Dublin, Kildare, Wicklow) was examined by small area (district electoral division), distance and clustering tendancies in relation to 83 landfills, five of which were major sites. The study included 2136 cases of congenital anomaly, 37,487 births and 1423 controls between 1986 and 1990. For the more populous areas of the region 50% of the population lived within 2-3 km of a landfill and within 4-5 km for more rural areas. In the area-level analysis, the standardised prevalence ratios, empirical and full Bayesian modelling, and Kulldorff\\'s spatial scan statistic found no association between the residential area of cases and location of landfills. In the case control analysis, the mean distance of cases and controls from the nearest landfill was similar. The odds ratios of cases compared to controls for increasing distances from all landfills and major landfills showed no significant difference from the baseline value of 1. The kernel and K methods showed no tendency of cases to cluster in relationship to landfills. In conclusion, congenital anomalies were not found to occur more commonly in proximity to municipal landfills.

  14. Landfill Barrier-Overview and Prospect

    Institute of Scientific and Technical Information of China (English)

    Zheng Liange; Zhao Yongsheng

    2000-01-01

    Landfill is the primary method of waste disposal. The increasing attention focused on the effect of landfill on environment prompts the development of environmental sound landfill system. As the key parts of landfill, the barrier system can provide impermeabilization of leachate and prevent biogas from escaping intotheenvironment. In recent years, the technology pertaining the barrier system developed rapidly. In this paper, new materials used in liners and new concept of barrier construction are reviewed; the mechanisms of leachate through clay liner and geomembrane, the calculation of leaks through liner and the effect of freezing/thaw on liner are discussed.

  15. Landfill leachate treatment by MBR: Performance and molecular weight distribution of organic contaminant

    Institute of Scientific and Technical Information of China (English)

    CHEN Shaohua; LIU Junxin

    2006-01-01

    A membrane bioreactor (MBR) with an air-lift bioreactor and gravity flow is applied to'treating landfill leachate. More than 99% of BOD5 (biochemical oxygen demand for five days) removal efficiency is achieved with less than 35 mg/L of BOD5 in the effluent at less than 1.71 kg BOD5/m3.d of BOD5 loading rate. When DO (dissolved oxygen) is maintained at the range of 2.3-2.8 mg/L and the loading rate of NH4+-N (ammonium nitrogen) is kept at 0.16-0.24 kg NH4+-N/m3.d, the NH4+-N in the effluent is less than 15 mg/L. However, compared with high removal rates of BOD5 and NH4+-N, the removal efficiency of soluble chemical oxygen demand (SCOD)varies between 70% and 96%. The investigation of molecular weight (MW) distribution has been carried out by the gel permeation chromatography (GPC) so as to understand the fate of organic matters in the MBR treating of landfill leachate. Results indicate that organic matters of the landfill leachate are composed of a high MW fraction (MW of the peak, MWp =11480-13182 Da) and a low MW fraction (MWp =158-275 Da). The high MW fraction is not biodegradable, but can be decreased with microfiltration membrane. The most of the low MW fraction is biodegradable, but the residue of the low MW fraction is able to permeate through the membrane, thus resulting in high SCOD in the effluent of the MBR.

  16. Landfills - LANDFILL_BOUNDARIES_IDEM_IN: Waste Site Boundaries in Indiana (Indiana Department of Environmental Management, Polygon Shapefile)

    Data.gov (United States)

    NSGIC State | GIS Inventory — LANDFILL_BOUNDARIES_IDEM_IN.SHP is a polygon shapefile that contains boundaries for open dump sites, approved landfills, and permitted landfills in Indiana, provided...

  17. Moving Denitrifying Bioreactors beyond Proof of Concept: Introduction to the Special Section.

    Science.gov (United States)

    Christianson, Laura E; Schipper, Louis A

    2016-05-01

    Denitrifying bioreactors are organic carbon-filled excavations designed to enhance the natural process of denitrification for the simple, passive treatment of nitrate-nitrogen. Research on and installation of these bioreactors has accelerated within the past 10 years, particularly in watersheds concerned about high nonpoint-source nitrate loads and also for tertiary wastewater treatment. This special section, inspired by the meeting of the Managing Denitrification in Agronomic Systems Community at the 2014 Annual Meeting of the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, aims to firmly establish that denitrifying bioreactors for treatment of nitrate in drainage waters, groundwater, and some wastewaters have moved beyond the proof of concept. This collection of 14 papers expands the peer-reviewed literature of denitrifying bioreactors into new locations, applications, and environmental conditions. There is momentum behind the pairing of wood-based bioreactors with other media (biochar, corn cobs) and in novel designs (e.g., use within treatment trains or use of baffles) to broaden applicability into new kinds of waters and pollutants and to improve performance under challenging field conditions such as cool early season agricultural drainage. Concerns about negative bioreactor by-products (nitrous oxide and hydrogen sulfide emissions, start-up nutrient flushing) are ongoing, but this translates into a significant research opportunity to develop more advanced designs and to fine tune management strategies. Future research must think more broadly to address bioreactor impacts on holistic watershed health and greenhouse gas balances and to facilitate collaborations that allow investigation of mechanisms within the bioreactor "black box."

  18. Evaluation of respiration in compost landfill biocovers intended for methane oxidation

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Pedicone, Alessio; Pedersen, Gitte Bukh

    2011-01-01

    will compete for O2 with other aerobic microorganisms. If the compost is not mature, a significant portion of the O2 diffusing into the compost layer will be consumed by non-methanotrophs, thereby limiting CH4 oxidation. The results of this study however also suggest that the consumption of O2 in the compost......A low-cost alternative approach to reduce landfill gas (LFG) emissions is to integrate compost into the landfill cover design in order to establish a biocover that is optimized for biological oxidation of methane (CH4). A laboratory and field investigation was performed to quantify respiration...... in an experimental compost biocover in terms of oxygen (O2) consumption and carbon dioxide (CO2) production and emission rates. O2 consumption and CO2 production rates were measured in batch and column experiments containing compost sampled from a landfill biowindow at Fakse landfill in Denmark. Column gas...

  19. Livingston Parish Landfill Methane Recovery Project (Feasibility Study)

    Energy Technology Data Exchange (ETDEWEB)

    White, Steven

    2012-11-15

    The Woodside Landfill is owned by Livingston Parish, Louisiana and is operated under contract by Waste Management of Louisiana LLC. This public owner/private operator partnership is commonplace in the solid waste industry today. The landfill has been in operation since approximately 1988 and has a permitted capacity of approximately 41 million cubic yards. Based on an assumed in-place waste density of 0.94 ton per cubic yard, the landfill could have an expected design capacity of 39.3 million tons. The landfill does have an active landfill gas collection and control system (LFGCCS) in place because it meets the minimum thresholds for the New Source Performance Standards (NSPS). The initial LFGCS was installed prior to 2006 and subsequent phases were installed in 2007 and 2010. The Parish received a grant from the United States Department of Energy in 2009 to evaluate the potential for landfill gas recovery and utilization at the Woodside Landfill. This includes a technical and economic feasibility study of a project to install a landfill gas to energy (LFGTE) plant and to compare alternative technologies. The LFGTE plant can take the form of on-site electrical generation, a direct use/medium Btu option, or a high-Btu upgrade technology. The technical evaluation in Section 2 of this report concludes that landfill gas from the Woodside landfill is suitable for recovery and utilization. The financial evaluations in sections 3, 4, and 5 of this report provide financial estimates of the returns for various utilization technologies. The report concludes that the most economically viable project is the Electricity Generation option, subject to the Parish’s ability and willingness to allocate adequate cash for initial capital and/or to obtain debt financing. However, even this option does not present a solid return: by our estimates, there is a 19 year simple payback on the electricity generation option. All of the energy recovery options discussed in this report

  20. Mechanobiologic Research in a Microgravity Environment Bioreactor

    Science.gov (United States)

    Guidi, A.; Dubini, G.; Tominetti, F.; Raimondi, M.

    mechanical forces. For example, cartilage constructs have been cultured in spinner flasks under mixed or unmixed conditions, in simulated and in real microgravity. In these mixing studies, however, it is difficult to definitively quantify the effects of mixing-induced mechanical forces from those of convection-enhanced transport of nutrients to and of catabolites away from the cells. At the state of the art, the presence of a more controlled mechanical environment may be the condition required in order to study the biochemical and mechanical response of these biological systems. Such a controlled environment could lead to an advanced fluid dynamic design of the culture chamber that could both enhance the local mass transfer phenomena and match the needs of specific macroscopic mechanical effects in tissue development. The bioreactor is an excellent example of how the skills and resources of two distinctly different fields can complement each other. Microgravity can be used to enhance the formation of tissue like aggregates in specially designed bioreactors. Theoretical and experimental projects are under way to improve cell culture techniques using microgravity conditions experienced during space flights. Bioreactors usable under space flight conditions impose constructional principles which are different from those intended solely for ground applications. The Columbus Laboratory as part of the International Space Station (ISS) will be an evolving facility in low Earth orbit. Its mission is to support scientific, technological, and commercial activities in space. A goal of this research is to design a unique bioreactor for use sequentially from ground research to space research. One of the particularities of the simulated microgravity obtained through time averaging of the weight vector is that by varying the rotational velocity the same results can be obtained with a different value of g. One of the first applications of this technique in space biology was in fact the

  1. Lactic acid Production with in situ Extraction in Membrane Bioreactor

    Directory of Open Access Journals (Sweden)

    Hamidreza Ghafouri Taleghani

    2017-01-01

    Full Text Available Background and Objective: Lactic acid is widely used in the food, chemical and pharmaceutical industries. The major problems associated with lactic acid production are substrate and end-product inhibition, and by-product formation. Membrane technologyrepresents one of the most effective processes for lactic acid production. The aim of this work is to increase cell density and lactic acid productivity due to reduced inhibition effect of substrate and product in membrane bioreactor.Material and Methods: In this work, lactic acid was produced from lactose in membrane bioreactor. A laboratory scale membrane bioreactor was designed and fabricated. Five types of commercial membranes were tested at the same operating conditions (transmembrane pressure: 500 KPa and temperature: 25°C. The effects of initial lactose concentration and dilution rate on biomass growth, lactic acid production and substrate utilization were evaluated.Results and Conclusion: The high lactose retention of 79% v v-1 and low lactic acid retention of 22% v v-1 were obtained with NF1 membrane; therefore, this membrane was selected for membrane bioreactor. The maximal productivity of 17.1 g l-1 h-1 was obtainedwith the lactic acid concentration of 71.5 g l-1 at the dilution rate of 0.24 h−1. The maximum concentration of lactic acid was obtained at the dilution rate of 0.04 h−1. The inhibiting effect of lactic acid was not observed at high initial lactose concentration. The critical lactose concentration at which the cell growth severely hampered was 150 g l-1. This study proved that membrane bioreactor had great advantages such as elimination of substrate and product inhibition, high concentration of process substrate, high cell density,and high lactic acid productivity.Conflict of interest: There is no conflict of interest.

  2. Biodegradation of the water-soluble gasoline components in a novel hybrid bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-De-Jesus, A.; Lara-Rodriguez, A.; Santoyo-Tepole, F.; Juarez-Ramirez, C.; Cristiani-Urbina, E.; Ruiz-Ordaz, N.; Galindez Mayer, J. [Escuela Nacional de Ciencias Biologicas, del Instituto Politecnico Nacional, Departamento de Ingenieria Bioquimica, Carpio y Plan de Ayala, ' ' Centro Operativo Naranjo' ' , Mexico, D.F. (Mexico)

    2003-07-01

    A novel hybrid bioreactor was designed to remove volatile organic compounds from water contaminated with water-soluble gasoline components, and the performance of this new bioreactor was investigated. It was composed of two biotrickling filter sections and one biofilter section. The liquid phase pollutants were removed by a mixed culture in the biotrickling filter sections and the gas phase pollutants stripped by air injection in the biofilter section. The specific rates of chemical oxygen demand (COD) removal obtained in the reactor were directly proportional to the pollutant-loading rate. A stable operation of the hybrid bioreactor was attained for long periods of time. The bioreactor had the potential to simultaneously treat a complex mixture of volatile organic compounds, e.g., those present in the water-soluble fraction of gasoline, as well as the capacity to readily adapt to changing operational conditions, such as an increased contaminant loading, and variations in the airflow rate. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  3. Three-Dimensional Modelling inside a Differential Pressure Laminar Flow Bioreactor Filled with Porous Media

    Directory of Open Access Journals (Sweden)

    Birgit Weyand

    2015-01-01

    Full Text Available A three-dimensional computational fluid dynamics- (CFD- model based on a differential pressure laminar flow bioreactor prototype was developed to further examine performance under changing culture conditions. Cell growth inside scaffolds was simulated by decreasing intrinsic permeability values and led to pressure build-up in the upper culture chamber. Pressure release by an integrated bypass system allowed continuation of culture. The specific shape of the bioreactor culture vessel supported a homogenous flow profile and mass flux at the scaffold level at various scaffold permeabilities. Experimental data showed an increase in oxygen concentration measured inside a collagen scaffold seeded with human mesenchymal stem cells when cultured in the perfusion bioreactor after 24 h compared to static culture in a Petri dish (dynamic: 11% O2 versus static: 3% O2. Computational fluid simulation can support design of bioreactor systems for tissue engineering application.

  4. Mswi bottom ash for upgrading of biogas and landfill gas.

    Science.gov (United States)

    Mostbauer, P; Lenz, S; Lechner, P

    2008-07-01

    A new upgrading process for biogas and landfill gas (LFG) has been designed recently by the authors' institute. The process uses the alkalinity of the fine fraction of bottom ash from municipal solid waste incineration (MSWI) for sorbing CO2 and H2S. Results from process development and optimisation are presented in this paper. It is expected that nearly pure CH4 can be produced for substitution of fossil fuels. Simultaneously, the leachability of MSWI bottom ash is clearly reduced.

  5. Optimizing of Culture Conditionin Horizontal Rotating Bioreactor

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionBioreactor is the most important equipment in tissue engineering. It can mimic the micro-environment of cell growth in vitro. At present, horizontal rotating bioreactor is the most advanced equipment for cell culture in the world. 2 Rotating bioreactors2.1 Working principleThere are two kinds of horizontal rotating bioreactor: HARV(high aspect ratio vessel) and RCCS (rotary cell culture system). It is drived by step motor with horizontal rotation, the culture medium and cell is filled between ...

  6. Advanced methods for bioreactor characterization.

    Science.gov (United States)

    Lübbert, A

    1992-08-01

    Bioreactors are characterized by the transport capacities they provide to optimally supply the microorganisms during production process. The transport is performed by flows induced in their cultivation media. In order to understand the extremely complex mixing, mass and heat transfer phenomena encountered, and to perceive their influences on bioreactor performance, sophisticated measuring techniques are required. This review compiles the developments currently in progress to surmount today's shortage of reliable measuring techniques. Measuring techniques are distinguished which can be used on different scales and their application spectra are illustrated by recently obtained results. Several new measuring techniques, which can be employed to resolve the flow structures, are discussed in detail. Only those techniques are considered which can be used to advantage during real cultivations in industrial-scale reactors.

  7. Monolithic Continuous-Flow Bioreactors

    Science.gov (United States)

    Stephanopoulos, Gregory; Kornfield, Julia A.; Voecks, Gerald A.

    1993-01-01

    Monolithic ceramic matrices containing many small flow passages useful as continuous-flow bioreactors. Ceramic matrix containing passages made by extruding and firing suitable ceramic. Pores in matrix provide attachment medium for film of cells and allow free movement of solution. Material one not toxic to micro-organisms grown in reactor. In reactor, liquid nutrients flow over, and liquid reaction products flow from, cell culture immobilized in one set of channels while oxygen flows to, and gaseous reaction products flow from, culture in adjacent set of passages. Cells live on inner surfaces containing flowing nutrient and in pores of walls of passages. Ready access to nutrients and oxygen in channels. They generate continuous high yield characteristic of immobilized cells, without large expenditure of energy otherwise incurred if necessary to pump nutrient solution through dense biomass as in bioreactors of other types.

  8. COD fractions of leachate from aerobic and anaerobic pilot scale landfill reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bilgili, M. Sinan [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: mbilgili@yildiz.edu.tr; Demir, Ahmet [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: ahmetd@yildiz.edu.tr; Akkaya, Ebru [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: ekoca@yildiz.edu.tr; Ozkaya, Bestamin [Yildiz Technical University, Environmental Engineering Department, 34349 Besiktas, Istanbul (Turkey)], E-mail: bozkaya@yildiz.edu.tr

    2008-10-01

    One of the most important problems with designing and maintaining a landfill is managing leachate that generated when water passes through the waste. In this study, leachate samples taken from aerobic and anaerobic landfill reactors operated with and without leachate recirculation are investigated in terms of biodegradable and non-biodegradable fractions of COD. The operation time is 600 days for anaerobic reactors and 250 days for aerobic reactors. Results of this study show that while the values of soluble inert COD to total COD in the leachate of aerobic landfill with leachate recirculation and aerobic dry reactors are determined around 40%, this rate was found around 30% in the leachate of anaerobic landfill with leachate recirculation and traditional landfill reactors. The reason for this difference is that the aerobic reactors generated much more microbial products. Because of this condition, it can be concluded that total inert COD/total COD ratios of the aerobic reactors were 60%, whereas those of anaerobic reactors were 50%. This study is important for modeling, design, and operation of landfill leachate treatment systems and determination of discharge limits.

  9. Landfill Site Selection by AHP Based Multi-criteria Decision Making Tool: A Case Study in Kolkata, India

    Science.gov (United States)

    Majumdar, Ankush; Hazra, Tumpa; Dutta, Amit

    2017-07-01

    This work presents a Multi-criteria Decision Making (MCDM) tool to select a landfill site from three candidate sites proposed for Kolkata Municipal Corporation (KMC) area that complies with accessibility, receptor, environment, public acceptability, geological and economic criteria. Analytical Hierarchy Process has been used to solve the MCDM problem. Suitability of the three sites (viz. Natagachi, Gangajoara and Kharamba) as landfills as proposed by KMC has been checked by Landfill Site Sensitivity Index (LSSI) as well as Economic Viability Index (EVI). Land area availability for disposing huge quantity of Municipal Solid Waste for the design period has been checked. Analysis of the studied sites show that they are moderately suitable for landfill facility construction as both LSSI and EVI scores lay between 300 and 750. The proposed approach represents an effective MCDM tool for siting sanitary landfill in growing metropolitan cities of developing countries like India.

  10. Application of wireless sensor network based on ZigBee technology in photo-bioreactors system

    Science.gov (United States)

    Liu, Bo; Chen, Ming; Chi, Tao

    2013-03-01

    A photo-bioreactor is a bioreactor that incorporates some types of light source to provide photonic energy input into the reactor[1][2]. In the situation of Large-scale industrialization production of micro-algae, hundreds of photo-bioreactors will be deployed in a factory, thus the design of entire system is based on the distribution theory and the remote monitoring must be deployed. So the communication in the entire photo-bioreactors system is very important. However, the recent solution of communication is based on RS-485 data bus, and the twisted-pair cable is used as the communication medium, so the flexibility and scalability of entire system reduce. In this paper, the wireless sensor network (WSN) based on ZigBee technology is applied to this photo-bioreactors system, and the related key problems include the architecture of entire system and the design of wireless sensor network nodes[3]~[6]. The application of this technology will also reduce the cost and effectively raise the intelligence level of the large-scale industrialization photo-bioreactors system.

  11. Bioreactor cultivation of anatomically shaped human bone grafts.

    Science.gov (United States)

    Temple, Joshua P; Yeager, Keith; Bhumiratana, Sarindr; Vunjak-Novakovic, Gordana; Grayson, Warren L

    2014-01-01

    In this chapter, we describe a method for engineering bone grafts in vitro with the specific geometry of the temporomandibular joint (TMJ) condyle. The anatomical geometry of the bone grafts was segmented from computed tomography (CT) scans, converted to G-code, and used to machine decellularized trabecular bone scaffolds into the identical shape of the condyle. These scaffolds were seeded with human bone marrow-derived mesenchymal stem cells (MSCs) using spinner flasks and cultivated for up to 5 weeks in vitro using a custom-designed perfusion bioreactor system. The flow patterns through the complex geometry were modeled using the FloWorks module of SolidWorks to optimize bioreactor design. The perfused scaffolds exhibited significantly higher cellular content, better matrix production, and increased bone mineral deposition relative to non-perfused (static) controls after 5 weeks of in vitro cultivation. This technology is broadly applicable for creating patient-specific bone grafts of varying shapes and sizes.

  12. Environmental impact assessment on the construction and operation of municipal solid waste sanitary landfills in developing countries: China case study.

    Science.gov (United States)

    Yang, Na; Damgaard, Anders; Lü, Fan; Shao, Li-Ming; Brogaard, Line Kai-Sørensen; He, Pin-Jing

    2014-05-01

    An inventory of material and energy consumption during the construction and operation (C&O) of a typical sanitary landfill site in China was calculated based on Chinese industrial standards for landfill management and design reports. The environmental impacts of landfill C&O were evaluated through life cycle assessment (LCA). The amounts of materials and energy used during this type of undertaking in China are comparable to those in developed countries, except that the consumption of concrete and asphalt is significantly higher in China. A comparison of the normalized impact potential between landfill C&O and the total landfilling technology implies that the contribution of C&O to overall landfill emissions is not negligible. The non-toxic impacts induced by C&O can be attributed mainly to the consumption of diesel used for daily operation, while the toxic impacts are primarily due to the use of mineral materials. To test the influences of different landfill C&O approaches on environmental impacts, six baseline alternatives were assessed through sensitivity analysis. If geomembranes and geonets were utilized to replace daily and intermediate soil covers and gravel drainage systems, respectively, the environmental burdens of C&O could be mitigated by between 2% and 27%. During the LCA of landfill C&O, the research scope or system boundary has to be declared when referring to material consumption values taken from the literature; for example, the misapplication of data could lead to an underestimation of diesel consumption by 60-80%.

  13. Bioleach: a mathematical model for the joint evaluation of leachate and biogas production in urban solid waste landfills

    Science.gov (United States)

    Rodrigo-Clavero, Maria-Elena; Rodrigo-Ilarri, Javier

    2017-04-01

    One of the most serious environmental problems in modern societies is the management and disposal of urban solid waste (MSW). Despite the efforts of the administration to promote recycling and reuse policies and energy recovery technologies, nowadays the majority of MSW still is disposed in sanitary landfills. During the phases of operation and post-closure maintenance of any solid waste disposal site, two of the most relevant problems are the production of leachate and the generation of biogas. The leachate and biogas production formation processes occur simultaneously over time and are coupled together through the consumption and/or production of water. However, no mathematical models have been easily identified that allow to the evaluation of the joint production of leachate and biogas, during the operational and the post-closure phase of an urban waste landfill. This paper introduces BIOLEACH, a new mathematical model programmed on a monthly scale, that evaluates the joint production of leachate and biogas applying water balance techniques and considers the management of the landfill as a bioreactor. The application of such a model on real landfills allows to perform an environmentally sustainable management that minimizes the environmental impacts produced being also economically more profitable.

  14. LANDFILL GAS PRETREATMENT FOR FUEL CELL APPLICATIONS

    Science.gov (United States)

    The paper discusses the U.S. EPA's program, underway at International Fuel Cells Corporation, to demonstrate landfill methane control and the fuel cell energy recovery concept. In this program, two critical issues are being addressed: (1) a landfill gas cleanup method that would ...

  15. Characterisation of landfills using a multidisciplinary approach

    NARCIS (Netherlands)

    Paap, B.F.; Bakker, M.A.J.; Hoekstra, N.K.; Oonk, H.

    2011-01-01

    The Netherlands has about 3800 abandoned landfills with a total surface of about 9000 ha. As they are often located near urban areas and their influence extends into their surrounding environment they put pressure on available space. Most abandoned landfills were in use until the 1960s and 1970s. Th

  16. Imaging scatterers in landfills using seismic interferometry

    NARCIS (Netherlands)

    Konstantaki, L.A.; Dragnov, D.S.; Heimovaara, T.J.; Ghose, R.

    2013-01-01

    A significant problem with landfills is their aftercare period. A landfill is considered to be safe for the environment only after a relatively long period of time. Until it reaches such a condition, it has to be periodically treated. Not only are treatments very expensive, but they could be dangero

  17. Quantifying capital goods for waste landfilling.

    Science.gov (United States)

    Brogaard, Line K; Stentsøe, Steen; Willumsen, Hans Christian; Christensen, Thomas H

    2013-06-01

    Materials and energy used for construction of a hill-type landfill of 4 million m(3) were quantified in detail. The landfill is engineered with a liner and leachate collections system, as well as a gas collection and control system. Gravel and clay were the most common materials used, amounting to approximately 260 kg per tonne of waste landfilled. The environmental burdens from the extraction and manufacturing of the materials used in the landfill, as well as from the construction of the landfill, were modelled as potential environmental impacts. For example, the potential impact on global warming was 2.5 kg carbon dioxide (CO2) equivalents or 0.32 milli person equivalents per tonne of waste. The potential impacts from the use of materials and construction of the landfill are low-to-insignificant compared with data reported in the literature on impact potentials of landfills in operation. The construction of the landfill is only a significant contributor to the impact of resource depletion owing to the high use of gravel and steel.

  18. Protein Expression in Insect and Mammalian Cells Using Baculoviruses in Wave Bioreactors.

    Science.gov (United States)

    Kadwell, Sue H; Overton, Laurie K

    2016-01-01

    Many types of disposable bioreactors for protein expression in insect and mammalian cells are now available. They differ in design, capacity, and sensor options, with many selections available for either rocking platform, orbitally shaken, pneumatically mixed, or stirred-tank bioreactors lined with an integral disposable bag (Shukla and Gottschalk, Trends Biotechnol 31(3):147-154, 2013). WAVE Bioreactors™ were among the first disposable systems to be developed (Singh, Cytotechnology 30:149-158, 1999). Since their commercialization in 1999, Wave Bioreactors have become routinely used in many laboratories due to their ease of operation, limited utility requirements, and protein expression levels comparability to traditional stirred-tank bioreactors. Wave Bioreactors are designed to use a presterilized Cellbag™, which is attached to a rocking platform and inflated with filtered air provided by the bioreactor unit. The Cellbag can be filled with medium and cells and maintained at a set temperature. The rocking motion, which is adjusted through angle and rock speed settings, provides mixing of oxygen (and CO2, which is used to control pH in mammalian cell cultures) from the headspace created in the inflated Cellbag with the cell culture medium and cells. This rocking motion can be adjusted to prevent cell shear damage. Dissolved oxygen and pH can be monitored during scale-up, and samples can be easily removed to monitor other parameters. Insect and mammalian cells grow very well in Wave Bioreactors (Shukla and Gottschalk, Trends Biotechnol 31(3):147-154, 2013). Combining Wave Bioreactor cell growth capabilities with recombinant baculoviruses engineered for insect or mammalian cell expression has proven to be a powerful tool for rapid production of a wide range of proteins.

  19. The Future Through the Past: The Use of Analog Sites for Design Criteria and Long Term Performance Assessment of Evapotranspiration Landfill Covers

    Energy Technology Data Exchange (ETDEWEB)

    Shafer, D. S.; Miller, J. J.; Young, M. H.; Edwards, S. C.; Rawlinson, S. E.

    2002-02-26

    There is growing support for using evapotranspiration (ET) covers for closure of low-level waste (LLW) and other types of waste disposal sites, particularly in the lower latitude arid regions of the western United States. At the Nevada Test Site (NTS), monolayer ET covers are the baseline technology for closure of LLW and mixed LLW cells. To better predict the long-term performance of monolayer ET covers, as well as to identify design criteria that will potentially improve their performance, the properties of, and processes occurring on, analog sites for ET covers on the NTS are being studied. The project is funded through the Subsurface Contaminants Focus Area of the U.S. Department of Energy. Four analog sites on the NTS have been selected to predict performance of ET covers over a 1,000-year compliance period. Two sites are relatively recently disturbed (within the last 50 years) and have been selected to evaluate processes and changes on ET covers for the early period after active cover maintenance is discontinued. Two other sites, late to mid-Holocene in age, are intended as analogs for the end of the compliance period (1,000 years or more); both surfaces are abandoned alluvial/colluvial deposits. The history of the early post-institutional control analog sites are being evaluated by an archaeologist to help determine when the sites were last disturbed or modified, and the mode of disturbance to help set baseline conditions. Similar to other ''landforms,'' ET covers will evolve over time because of pedogenic, biotic, and climatic processes. Properties of analog sites that could affect ET water balance performance will be evaluated to help understand ET cover performance over time.

  20. Qualitative Research and Evaluation of Landfill Leachate

    Directory of Open Access Journals (Sweden)

    Irina Kačinskaja

    2013-12-01

    Full Text Available Currently, depositing municipal waste in landfills is the dominating method in Lithuania. A large amount of landfill leachate is the main environmental problem. Municipal waste landfill leachate is characterized by high biochemical oxygen demand (BOD containing a number of heavy metals and concentration of organic compounds. The colmatation of landfill leachate collection systems is another burning problem that occurs due to certain characteristics of leachate such as suspended solids, an increase in calcium and magnesium concentrations and vital activity of microorganisms. Therefore, it is necessary to examine conditions affecting these parameters. The paper presents and analyses the characteristics of experimental data, assesses the factors having the greatest influence on recent development and introduces the measures that should be taken into account so that to the ensure optimal operation of the systems for collecting municipal waste landfill leachate.Article in Lithuanian

  1. Biogeochemistry of landfill leachate plumes

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Kjeldsen, Peter; Bjerg, Poul Løgstrup

    2001-01-01

    is on dissolved organic matter, xenobiotic organic compounds, inorganic macrocomponents as anions and cations, and heavy metals. Laboratory as well as field investigations are included. This review is an up-date of an earlier comprehensive review. The review shows that most leachate contamination plumes...... the behavior of the contaminants in the plume as the leachate migrates away from the landfill. Diverse microbial communities have been identified in leachate plumes and are believed to be responsible for the redox processes. Dissolved organic C in the leachate, although it appears to be only slowly degradable...

  2. Fluxes of methane between landfills and the atmosphere: Natural and engineered controls

    Energy Technology Data Exchange (ETDEWEB)

    Bogner, J. [Argonne National Lab., IL (United States); Meadows, M. [ETSU, Harwell, Oxfordshire (United Kingdom); Czepiel, P. [Harvard Univ., Cambridge, MA (United States)

    1997-08-01

    Field measurement of landfill methane emissions indicates natural variability spanning more than 2 seven orders of magnitude, from approximately 0.0004 to more than 4000 g m{sub -2} day{sup -1}. This wide range reflects net emissions resulting from production (methanogenesis), consumption (methanotrophic oxidation), and gaseous transport processes. The determination of an {open_quotes}average{close_quotes} emission rate for a given field site requires sampling designs and statistical techniques which consider spatial and temporal variability. Moreover, particularly at sites with pumped gas recovery systems, it is possible for methanotrophic microorganisms in aerated cover soils to oxidize all of the methane from landfill sources below and, additionally, to oxidize methane diffusing into cover soils from atmospheric sources above. In such cases, a reversed soil gas concentration gradient is observed in shallow cover soils, indicating bidirectional diffusional transport to the depth of optimum methane oxidation. Rates of landfill methane oxidation from field and laboratory incubation studies range up to 166 g m{sup -2} day{sup -1} among the highest for any natural setting, providing an effective natural control on net emissions. Estimates of worldwide landfill methane emissions to the atmosphere have ranged from 9 to 70 Tg yr{sup -1}, differing mainly in assumed methane yields from estimated quantities of landfilled refuse. At highly controlled landfill sites in developed countries, landfill methane is often collected via vertical wells or horizontal collectors. Recovery of landfill methane through engineered systems can provide both environmental and energy benefits by mitigating subsurface migration, reducing surface emissions, and providing an alternative energy resource for industrial boiler use, on-site electrical generation, or upgrading to a substitute natural gas.

  3. Evaluation of the Oedometer Tests of Municipal Landfill Waste Material

    Directory of Open Access Journals (Sweden)

    Imre Emőke

    2014-07-01

    Full Text Available The aim of the ongoing research is (i to develop a new biodegradation landfill technique so that the landfill gas production could be controlled and the utilisation of the landfill gas could economically be optimized, (ii to plan the energy utilisation of the landfill including individual and combined solutions (solar, wind, geothermal energy, energy storage using methanol etc.. [1, 2, 3

  4. Assessing the environmental impact of ashes used in a landfill cover construction.

    Science.gov (United States)

    Travar, I; Lidelöw, S; Andreas, L; Tham, G; Lagerkvist, A

    2009-04-01

    Large amounts of construction materials will be needed in Europe in anticipation for capping landfills that will be closed due to the tightening up of landfill legislation. This study was conducted to assess the potential environmental impacts of using refuse derived fuel (RDF) and municipal solid waste incineration (MSWI) ashes as substitutes for natural materials in landfill cover designs. The leaching of substances from a full-scale landfill cover test area built with different fly and bottom ashes was evaluated based on laboratory tests and field monitoring. The water that drained off above the liner (drainage) and the water that percolated through the liner into the landfill (leachate) were contaminated with Cl(-), nitrogen and several trace elements (e.g., As, Cu, Mo, Ni and Se). The drainage from layers containing ash will probably require pre-treatment before discharge. The leachate quality from the ash cover is expected to have a minor influence on overall landfill leachate quality because the amounts generated from the ash covers were low, construction, which could contribute to the retention of trace elements in the liner in the long term. Hence, from an environmental view point, the placement of ashes in layers above the liner is more critical than within the liner.

  5. Denitrification 'Woodchip' Bioreactors for Productive and Sustainable Agricultural Systems

    Science.gov (United States)

    Christianson, L. E.; Summerfelt, S.; Sharrer, K.; Lepine, C.; Helmers, M. J.

    2014-12-01

    Growing alarm about negative cascading effects of reactive nitrogen in the environment has led to multifaceted efforts to address elevated nitrate-nitrogen levels in water bodies worldwide. The best way to mitigate N-related impacts, such as hypoxic zones and human health concerns, is to convert nitrate to stable, non-reactive dinitrogen gas through the natural process of denitrification. This means denitrification technologies need to be one of our major strategies for tackling the grand challenge of managing human-induced changes to our global nitrogen cycle. While denitrification technologies have historically been focused on wastewater treatment, there is great interest in new lower-tech options for treating effluent and drainage water from one of our largest reactive nitrogen emitters -- agriculture. Denitrification 'woodchip' bioreactors are able to enhance this natural N-conversion via addition of a solid carbon source (e.g., woodchips) and through designs that facilitate development of anoxic conditions required for denitrification. Wood-based denitrification technologies such as woodchip bioreactors and 'sawdust' walls for groundwater have been shown to be effective at reducing nitrate loads in agricultural settings around the world. Designing these systems to be low-maintenance and to avoid removing land from agricultural production has been a primary focus of this "farmer-friendly" technology. This presentation provides a background on woodchip bioreactors including design considerations, N-removal performance, and current research worldwide. Woodchip bioreactors for the agricultural sector are an accessible new option to address society's interest in improving water quality while simultaneously allowing highly productive agricultural systems to continue to provide food in the face of increasing demand, changing global diets, and fluctuating weather.

  6. Membrane bioreactors for waste gas treatment.

    NARCIS (Netherlands)

    Reij, M.W.; Keurentjes, J.T.F.; Hartmans, S.

    1998-01-01

    This review describes the recent development of membrane reactors for biological treatment of waste gases. In this type of bioreactor gaseous pollutants are transferred through a membrane to the liquid phase, where micro-organisms degrade the pollutants. The membrane bioreactor combines the

  7. Oxygen mass transfer and scale-up studies in baffled roller bioreactors.

    Science.gov (United States)

    Nikakhtari, H; Song, W; Nemati, M; Hill, G A

    2014-02-01

    Oxygen mass transfer was studied in conventional, bead mill and baffled roller bioreactors. Using central composite rotational design, impacts of size, rotation speed and working volume on the oxygen mass transfer were evaluated. Baffled roller bioreactor outperformed its conventional and bead mill counterparts, with the highest k(L)a obtained in these configurations being 0.58, 0.19, 0.41 min(-1), respectively. Performances of the bead mill and baffled roller bioreactor were only comparable when a high bead loading (40%) was applied. Regardless of configuration increase in rotation speed and decrease in working volume improved the oxygen mass transfer rate. Increase in size led to enhanced mass transfer and higher k(L)a in baffled roller bioreactor (0.49 min(-1) for 2.2 L and 1.31 min(-1) for 55 L bioreactors). Finally, the experimentally determined k(L)a in the baffled roller bioreactors of different sizes fit reasonably well to an empirical correlation describing the k(L)a in terms of dimensionless numbers.

  8. 3D Printed Vascular Networks Enhance Viability in High-Volume Perfusion Bioreactor.

    Science.gov (United States)

    Ball, Owen; Nguyen, Bao-Ngoc B; Placone, Jesse K; Fisher, John P

    2016-12-01

    There is a significant clinical need for engineered bone graft substitutes that can quickly, effectively, and safely repair large segmental bone defects. One emerging field of interest involves the growth of engineered bone tissue in vitro within bioreactors, the most promising of which are perfusion bioreactors. Using bioreactor systems, tissue engineered bone constructs can be fabricated in vitro. However, these engineered constructs lack inherent vasculature and once implanted, quickly develop a necrotic core, where no nutrient exchange occurs. Here, we utilized COMSOL modeling to predict oxygen diffusion gradients throughout aggregated alginate constructs, which allowed for the computer-aided design of printable vascular networks, compatible with any large tissue engineered construct cultured in a perfusion bioreactor. We investigated the effect of 3D printed macroscale vascular networks with various porosities on the viability of human mesenchymal stem cells in vitro, using both gas-permeable, and non-gas permeable bioreactor growth chamber walls. Through the use of 3D printed vascular structures in conjunction with a tubular perfusion system bioreactor, cell viability was found to increase by as much as 50% in the core of these constructs, with in silico modeling predicting construct viability at steady state.

  9. Verification of energy dissipation rate scalability in pilot and production scale bioreactors using computational fluid dynamics.

    Science.gov (United States)

    Johnson, Chris; Natarajan, Venkatesh; Antoniou, Chris

    2014-01-01

    Suspension mammalian cell cultures in aerated stirred tank bioreactors are widely used in the production of monoclonal antibodies. Given that production scale cell culture operations are typically performed in very large bioreactors (≥ 10,000 L), bioreactor scale-down and scale-up become crucial in the development of robust cell-culture processes. For successful scale-up and scale-down of cell culture operations, it is important to understand the scale-dependence of the distribution of the energy dissipation rates in a bioreactor. Computational fluid dynamics (CFD) simulations can provide an additional layer of depth to bioreactor scalability analysis. In this communication, we use CFD analyses of five bioreactor configurations to evaluate energy dissipation rates and Kolmogorov length scale distributions at various scales. The results show that hydrodynamic scalability is achievable as long as major design features (# of baffles, impellers) remain consistent across the scales. Finally, in all configurations, the mean Kolmogorov length scale is substantially higher than the average cell size, indicating that catastrophic cell damage due to mechanical agitation is highly unlikely at all scales.

  10. Landfills: Engineering Design for Waste Control

    Science.gov (United States)

    Deck, Anita; Grubbs, Michael E.

    2016-01-01

    It is becoming increasingly important to consider the waste humans produce and options for reducing the impact it has on the environment. Allowing students the opportunities to research potential solutions and present their ideas results in an educated citizenry that considers consequences of technological advances. Throughout the course of a…

  11. Microbial activity in the landfill soil.

    Science.gov (United States)

    Brzezinska, M Swiontek; Burkowska, A; Walczak, M

    2012-01-01

    The research objective was to determine the activity of microorganisms in the soil exposed to direct influence of a landfill, as well as in the soil beyond its influence. Fluorescein diacetate (FDA) hydrolytic activity and respiration in the soil were determined. The highest number of cultivated bacteria was recorded at the site located within the zone of direct influence exerted by the landfill, whereas the least amount was found at a distance of 1000 metres from the landfill. In contrast, the largest numbers of molds were observed in the soil at a distance of 1000 m from the headquarters of the landfill. The highest FDA hydrolytic activity and biological oxygen demand (BOD5) were recorded in the soil by the headquarters of the landfill, and the least parameters were revealed at a distance of 1000 m from the landfill. It was found a high correlation between the number of bacteria and FDA hydrolytic activity of soil and BOD5 in the north-eastern of the landfill. However, in the same place, there is a low correlation between the number of molds, and FDA hydrolytic activity of soil and BOD5.

  12. Hydrodynamic Characterization of a Column-type Prototype Bioreactor

    Science.gov (United States)

    Espinosa-Solares, Teodoro; Morales-Contreras, Marcos; Robles-Martínez, Fabián; García-Nazariega, Melvin; Lobato-Calleros, Consuelo

    Agro-food industrial processes produce a large amount of residues, most of which are organic. One of the possible solutions for the treatment of these residues is anaerobic digestion in bioreactors. A novel 18-L bioreactor for treating waste water was designed based on pneumatic agitation and semispherical baffles. Flow patterns were visualized using the particle tracer technique. Circulation times were measured with the particle tracer and the thermal technique, while mixing times were measured using the thermal technique. Newtonian fluid and two non-Newtonian fluids were used to simulate the operational conditions. The results showed that the change from Newtonian to non-Newtonian properties reduces mixed zones and increases circulation and mixing times. Circulation time was similar when evaluated with the thermal and the tracer particle methods. It was possible to predict dimensionless mixing time (θm) using an equivalent Froude number (Fr eq).

  13. Closure Alternatives for Municipal Waste Landfills.Study Case: Municipal Waste Landfill Medias,Sibiu County

    Directory of Open Access Journals (Sweden)

    MIHĂIESCU R.

    2010-12-01

    Full Text Available In the recent decades, the environmental impact produced by municipal solid wastes has received specialattention. All new EU countries are involved in the process of implementation of the European Council Directive31/99/EC on the landfill of waste in the European Union. As consequence National legislation, adapted to fit the EUrequirements, focuses on integrated waste management and environmental control of municipal solid waste landfills,from start-up to closure and assimilation into the environment. In Romania, by Government decision, HG 349/2005,was established the obligatoriness of closing unconform waste landfills located in urban areas starting at July 2009. Asconsequence the owner of municipal waste landfill Medias started the proceedings of closure for the landfill. The aim ofthis study is to compare, from an environmental point of view, different alternatives for the closure of the municipalsolid waste landfill Somard-Medias (Romania.

  14. Hydrodynamic characteristics of UASB bioreactors.

    Science.gov (United States)

    John, Siby; Tare, Vinod

    2011-10-01

    The hydrodynamic characteristics of UASB bioreactors operated under different organic loading and hydraulic loading rates were studied, using three laboratory scale models treating concocted sucrose wastewater. Residence time distribution (RTD) analysis using dispersion model and tanks-in-series model was directed towards the characterization of the fluid flow pattern in the reactors and correlation of the hydraulic regime with the biomass content and biogas production. Empty bed reactors followed a plug flow pattern and the flow pattern changed to a large dispersion mixing with biomass and gas production. Effect of increase in gas production on the overall hydraulics was insignificant.

  15. Alternative landfill cover technology demonstration at Kaneohe Marine Corps Base Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Karr, L.A.; Harre, B. [Naval Facilities Engineering Service Center, Port Hueneme, CA (United States); Hakonson, T.E. [Colorado State Univ., Fort Collins, CO (United States)

    1997-12-31

    Surface covers to control water infiltration to waste buried in landfills will be the remediation alternative of choice for most hazardous and sanitary landfills operated by the Department of Defense. Although surface covers are the least expensive method of remediation for landfills, they can still be expensive solutions. Conventional wisdom suggests that landfill capping technology is well developed as evidenced by the availability of EPA guidance for designing and constructing what has become known as the {open_quotes}RCRA Cap{close_quotes}. In practice, however, very little testing of the RCRA cap, or any other design, has been done to evaluate how effective these designs are in limiting infiltration of water into waste. This paper describes a low cost alternative to the {open_quotes}RCRA Cap{close_quotes} that is being evaluated at Marine Corps Base Hawaii (MCBH) Kaneohe Bay. This study uses an innovative, simple and inexpensive concept to manipulate the fate of water falling on a landfill. The infiltration of water through the cap will be controlled by combining the evaporative forces of vegetation to remove soil water, with engineered structures that limit infiltration of precipitation into the soil. This approach relies on diverting enough of the annual precipitation to runoff, so that the water that does infiltrate into the soil can easily be removed by evapotranspiration.

  16. Life cycle assessment (LCA) of solid waste management strategies in Tehran: landfill and composting plus landfill.

    Science.gov (United States)

    Abduli, M A; Naghib, Abolghasem; Yonesi, Mansoor; Akbari, Ali

    2011-07-01

    As circumstances of operating and maintenance activities for landfilling and composting in Tehran metropolis differ from those of cities in developed countries, it was concluded to have an environmental impact comparison between the current solid waste management (MSW) strategies: (1) landfill, and (2) composting plus landfill. Life cycle assessment (LCA) was used to compare these scenarios for MSW in Tehran, Iran. The Eco-Indicator 99 is applied as an impact assessment method considering surplus energy, climate change, acidification, respiratory effect, carcinogenesis, ecotoxicity and ozone layer depletion points of aspects. One ton of municipal solid waste of Tehran was selected as the functional unit. According to the comparisons, the composting plus landfill scenario causes less damage to human health in comparison to landfill scenario. However, its damages to both mineral and fossil resources as well as ecosystem quality are higher than the landfill scenario. Thus, the composting plus landfill scenario had a higher environmental impact than landfill scenario. However, an integrated waste management will ultimately be the most efficient approach in terms of both environmental and economic benefits. In this paper, a cost evaluation shows that the unit cost per ton of waste for the scenarios is 15.28 and 26.40 US$, respectively. Results show landfill scenario as the preferable option both in environmental and economic aspects for Tehran in the current situation.

  17. Optimal homogenization of perfusion flows in microfluidic bio-reactors; a numerical study

    CERN Document Server

    Okkels, Fridolin; Bruus, Henrik

    2009-01-01

    To ensure homogeneous conditions within the complete area of perfused microfluidic bio-reactors, we develop a general design of a continuously feed bio-reactor with uniform perfusion flow. This is achieved by introducing a specific type of perfusion inlet to the reaction area. The geometry of these inlets are found using the methods of topology optimization and shape optimization. The results are compared with two different analytic models, from which a general parametric description of the design is obtained and tested numerically. Such a parametric description will generally be beneficial for the design of a broad range of microfluidic bioreactors used for e.g. cell culturing and analysis, and in feeding bio-arrays.

  18. Development of a Cyclic Strain Bioreactor for Mechanical Enhancement and Assessment of Bioengineered Myocardial Constructs.

    Science.gov (United States)

    Salazar, Betsy H; Cashion, Avery T; Dennis, Robert G; Birla, Ravi K

    2015-12-01

    The purpose of this study was to develop enabling bioreactor technologies using a novel voice coil actuator system for investigating the effects of periodic strain on cardiac patches fabricated with rat cardiomyocytes. The bioengineered muscle constructs used in this study were formed by culturing rat neonatal primary cardiac cells on a fibrin gel. The physical design of the bioreactor was initially conceived using Solidworks to test clearances and perform structural strain analysis. Once the software design phase was completed the bioreactor was assembled using a combination of commercially available, custom machined, and 3-D printed parts. We utilized the bioreactor to evaluate the effect of a 4-h stretch protocol on the contractile properties of the tissue after which immunohistological assessment of the tissue was also performed. An increase in contractile force was observed after the strain protocol of 10% stretch at 1 Hz, with no significant increase observed in the control group. Additionally, an increase in cardiac myofibril alignment, connexin 43 expression, and collagen type I distribution were noted. In this study we demonstrated the effectiveness of a new bioreactor design to improve contractility of engineered cardiac muscle tissue.

  19. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS - PHASE I FINAL REPORT: CONCEPTUAL STUDY

    Science.gov (United States)

    The report discusses results of a conceptual design, cost, and evaluation study of energy recovery from landfill gas using a commercial phosphoric acid fuel cell power plant. The conceptual design of the fuel cell energy recovery system is described, and its economic and environm...

  20. Hydrologic Evaluation of Landfill Performance (HELP) Model

    Science.gov (United States)

    The program models rainfall, runoff, infiltration, and other water pathways to estimate how much water builds up above each landfill liner. It can incorporate data on vegetation, soil types, geosynthetic materials, initial moisture conditions, slopes, etc.

  1. Landfills in the Western United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Locations of landfills and waste transfer stations in 11 western states. Data was obtained from state and federal agencies in GIS, tabular, and map format.

  2. Influence of aeration modes on leachate characteristic of landfills that adopt the aerobic-anaerobic landfill method.

    Science.gov (United States)

    Wu, Chuanfu; Shimaoka, Takayuki; Nakayama, Hirofumi; Komiya, Teppei; Chai, Xiaoli; Hao, Yongxia

    2014-01-01

    As far as the optimal design, operation, and field application of the Aerobic-Anaerobic Landfill Method (AALM) are concerned, it is very important to understand how aeration modes (different combinations of aeration depth and air injection rate) affect the biodegradation of organic carbon and the transformation of nitrogen in landfill solid waste. Pilot-scale lysimeter experiments were carried out under different aeration modes to obtain detailed information regarding the influence of aeration modes on leachate characteristics. Results from these lysimeter experiments revealed that aeration at the bottom layer was the most effective for decomposition of organic carbon when compared with aeration at the surface or middle layers. Moreover, the air injection rate led to different nitrogen transformation patterns, unlike the lesser influence it has on organic carbon decomposition. Effective simultaneous nitrification and denitrification were observed for the aeration mode with a higher air injection rate (=1.0 L/min). On the other hand, the phenomenon of sequenced nitrification and denitrification could be observed when a low air injection rate (=0.5L/min.) was employed. Finally, it is concluded that, for AALM, air injection with a higher air injection rate at the deepest layer near the leachate collection pipe tends to accelerate the stabilization of landfill waste as defined in terms of the enhancement of denitrification as well as organic carbon decomposition.

  3. INPP Landfill[Disposal of very low level radioactive waste at Ignalina NPP

    Energy Technology Data Exchange (ETDEWEB)

    Dahlberg, Jan; Bergstroem, Ulla

    2004-06-15

    The objective of this report is to propose the basic design for final disposal of Very Low Level Radioactive Waste (VLLW) produced at the Ignalina Nuclear Power Plant and at other small waste producers in Lithuania. Considering the safety for the environment, as well as the construction costs, it has been decided that the repository will be of a landfill type based on the same design principles as similar authorised facilities in other countries. It has also been decided that the location of the landfill shall be in the vicinity of the Ignalina Nuclear Power Plant (INPP)

  4. Constrained linear control design of continuous bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Tarbouriech, S.; Queinnec, I.

    1994-12-31

    The control problem of a continuous bio-process is expressed in terms of stabilization and disturbances attenuation of an uncertain linear system under state and control constraints. A static output feedback is realized to obtain a suitable Eigen-structure assignment in closed-loop; then a positively invariant set of admissible initial states is determined by using cones properties, in order to respect the constraints. (authors) 19 refs.

  5. Bioreactors for tissue engineering--a new role for perfusionists?

    Science.gov (United States)

    Sistino, Joseph J

    2003-09-01

    Tissue engineering is an exciting new area of medicine with rapid growth and expansion over the last decade. It has the potential to have a profound impact on the practice of medicine and influence the economic development in the industry of biotechnology. In almost every specialty of medicine, the ability to generate replacement cells and develop tissues will change the focus from artificial organs and transplantation to growing replacement organs from the patient's own stem cells. Once these organs are at a size that requires perfusion to maintain oxygen and nutrient delivery, then automated perfusion systems termed "bioreactors" will be necessary to sustain the organ until harvesting. The design of these "bioreactors" will have a crucial role in the maintenance of cellular function throughout the growth period. The perfusion schemes necessary to determine the optimal conditions have not been well elucidated and will undergo extensive research over the next decade. The key to progress in this endeavor will development of long-term perfusion techniques and identifying the ideal pressures, flow rates, type of flow (pulsatile/nonpulsatile), and perfusate solution. Perfusionists are considered experts in the field of whole body perfusion, and it is possible that they can participate in the development and operation of these "bioreactors." Additional education of perfusionists in the area of tissue engineering is necessary in order for them to become integral parts of this exciting new area of medicine.

  6. Biological Nutrient Removal in an Intermittently Aerated Bioreactor

    Directory of Open Access Journals (Sweden)

    J. Derco

    2017-07-01

    Full Text Available The extension of biological processes from carbonaceous impurities removal to nitrogen and phosphorus removal had an impact on the biological system configuration. The system must be well designed, optimized, and operated at its optimum in order to meet the ever more stringent effluent standards. An intermittently aerated completely mixed lab-scale activated sludge bioreactor (IACMB has been used for modelling biological processes of nutrients removal. Concerning the nitrogen removal, the operating cycles 15–30 (15 minutes of aeration, 30 minutes of only mixing without aeration and 30–30 were tested. For the experiments with luxury uptake processes, the operating cycles 15–45, 15–90, 30–60 and 15–75 were used. The cycle 15–75 was the most satisfactory with convenient lengths of aerobic, anoxic, and anaerobic period, high efficiency of the nitrification and denitrification processes, and significant decrease in phosphorus concentration. The results have shown that the intermittently aerated bioreactors are suitable for nitrogen removal as well as luxury uptake of phosphorus. The main advantage is high flexibility in maintenance and control of biochemical environments in the bioreactor.

  7. Sulfur formation and recovery in a thiosulfate-oxidizing bioreactor.

    Science.gov (United States)

    González-Sánchez, A; Meulepas, R; Revah, S

    2008-08-01

    This work describes the design and performance of a thiosulfate-oxidizing bioreactor that allowed high elemental sulfur production and recovery efficiency. The reactor system, referred to as a Supernatant-Recycling Settler Bioreactor (SRSB), consisted of a cylindrical upflow reactor and a separate aeration vessel. The reactor was equipped with an internal settler and packing material (structured corrugated PVC sheets) to facilitate both cell retention and the settling of the formed elemental sulfur. The supernatant from the reactor was continuously recirculated through the aerator. An inlet thiosulfate concentration of 100 mmol l(-1) was used. The reactor system was fed with 89 mmol l(-1) d(-1) thiosulfate reaching 98 to 100% thiosulfate conversion with an elemental sulfur yield of 77%. Ninety-three percent of the produced sulfur was harvested from the bottom of the reactor as sulfur sludge. The dry sulfur sludge contained 87% elemental sulfur. The inclusion of an internal settler and packing material in the reactor system resulted in an effective retention of sulfur and biomass inside the bioreactor, preventing the oxidation of thiosulfate and elemental sulfur to sulfate in the aerator and, therefore, improving the efficiency of elemental sulfur formation and recovery.

  8. Tubular membrane bioreactors for biotechnological processes.

    Science.gov (United States)

    Wolff, Christoph; Beutel, Sascha; Scheper, Thomas

    2013-02-01

    This article is an overview of bioreactors using tubular membranes such as hollow fibers or ceramic capillaries for cultivation processes. This diverse group of bioreactor is described here in regard to the membrane materials used, operational modes, and configurations. The typical advantages of this kind of system such as environments with low shear stress together with high cell densities and also disadvantages like poor oxygen supply are summed up. As the usage of tubular membrane bioreactors is not restricted to a certain organism, a brief overview of various applications covering nearly all types of cells from prokaryotic to eukaryotic cells is also given here.

  9. Bioreactor Technology in Cardiovascular Tissue Engineering

    Science.gov (United States)

    Mertsching, H.; Hansmann, J.

    Cardiovascular tissue engineering is a fast evolving field of biomedical science and technology to manufacture viable blood vessels, heart valves, myocar-dial substitutes and vascularised complex tissues. In consideration of the specific role of the haemodynamics of human circulation, bioreactors are a fundamental of this field. The development of perfusion bioreactor technology is a consequence of successes in extracorporeal circulation techniques, to provide an in vitro environment mimicking in vivo conditions. The bioreactor system should enable an automatic hydrodynamic regime control. Furthermore, the systematic studies regarding the cellular responses to various mechanical and biochemical cues guarantee the viability, bio-monitoring, testing, storage and transportation of the growing tissue.

  10. Spatial Experiment Technologies Suitable for Unreturnable Bioreactor

    Science.gov (United States)

    Zhang, Tao; Zheng, Weibo; Tong, Guanghui

    2016-07-01

    The system composition and main function of the bioreactor piggybacked on TZ cargo transport spacecraft are introduced briefly in the paper.The spatial experiment technologies which are suitable for unreturnable bioreactor are described in detail,including multi-channel liquid transportion and management,multi-type animal cells circuit testing,dynamic targets microscopic observation in situ etc..The feasibility and effectiveness of these technologies which will be used in space experiment in bioreactor are verified in tests and experiments on the ground.

  11. Development of Fundamental Technologies for Micro Bioreactors

    Science.gov (United States)

    Sato, Kiichi; Kitamori, Takehiko

    This chapter reviews the development of fundamental technologies required for microchip-based bioreactors utilizing living mammalian cells and pressure driven flow. The most important factor in the bioreactor is the cell culture. For proper cell culturing, continuous medium supply from a microfluidic channel and appropriate modification of the channel surface to accommodate cell attachment is required. Moreover, the medium flow rate should be chosen carefully, because shear stress affects cell activity. The techniques presented here could be applied to the development of micro bioreactors such as microlivers, pigment production by plant cells, and artificial insemination.

  12. Engineering cellulosic bioreactors by template assisted DNA shuffling and in vitro recombination (TADSir).

    Science.gov (United States)

    Davis, Leroy K

    2014-10-01

    The current study focuses on development of a bioreactor engineering strategy based on exploitation of the Arabidopsis thaliana genome. Chimeric A. thaliana glycosyl hydrolase (GH) gene libraries were assembled using a novel directed evolution strategy (TADSir: template assisted DNA shuffling and in vitro recombination) that promotes DNA recombination by reassembly of DNA fragments on unique gene templates. TADSir was modeled using a set of algorithms designed to simulate DNA interactions based on nearest neighbor base stacking interactions and Gibb's free energy differences between helical coil and folded DNA states. The algorithms allow for target gene prediction and for in silica analysis of chimeric gene library composition. Further, the study investigated utilization of A. thaliana GH sequence space for bioreactor design by evolving 20 A. thaliana genes representing the GH1, GH3, GH5, GH9 and GH10 gene families. Notably, TADSir achieved streamlined engineering of Saccharomyces cerevisiae and spinach mesophyll protoplast bioreactors capable of processing CM cellulose, Avicel and xylan.

  13. Suspension cell culture in microgravity and development of a space bioreactor

    Science.gov (United States)

    Morrison, Dennis R.

    1987-01-01

    NASA has methodically developed unique suspension type cell and recovery apparatus culture systems for bioprocess technology experiments and production of biological products in microgravity. The first space bioreactor has been designed for microprocessor control, no gaseous headspace, circulation and resupply of culture medium, and slow mixing in very low shear regimes. Various ground based bioreactors are being used to test reactor vessel design, on-line sensors, effects of shear, nutrient supply, and waste removal from continuous culture of human cells attached to microcarriers. The small (500 ml) bioreactor is being constructed for flight experiments in the Shuttle middeck to verify systems operation under microgravity conditions and to measure the efficiencies of mass transport, gas transfer, oxygen consumption, and control of low shear stress on cells.

  14. Performance of tapered column packed-bed bioreactor for ethanol production.

    Science.gov (United States)

    Hamamci, H; Ryu, D D

    1987-06-01

    A tapered column type of bioreactor system packed with immobilized Saccharomyces cerevisiae was used to study the bioreactor performance as a function of design and operating variables. The performance of tapered column bioreactor system was found to be better than that of the conventional cylindrical column reactor system for the ethanol fermentation. The new bioreactor design alleviated problems associated with carbon dioxide evolution and provided a significantly better flow pattern for both liquid and gas phases in the bioreactor without local channelling. A mathematical simulation model, which takes into account of the axial convection and dispersion, interphase mass transfer, and apparent kinetic design parameters, was developed. The effect of radial concentration gradients on the bioreactor performance was found to be insignificant. For the reactor system studied, the maximum ethanol productivity obtained was 60 g ethanol/L gel/h, and the maximum glucose assimilation rate was 140 g glucose/L gel/h. One of the most important findings from this study was that the apparent kinetic parameters change at the glucose concentration of 2 g/L This change was found to be due to the changes in yeast physiology and metabolism. The values of V(m) (') and V(m) (') decreased from 0.8 to 0.39 g ethanol/g cell/h and from 97mM to 11mM, respectively. The substrate inhibition constant was estimated as 0.76M and the product inhibition constant was determined as 113 g ethanol/L The degree of product inhibition showed practically a linear relationship with an increasing ethanol concentration. Based on the hydro-dynamic analysis of the bioreactor system, it was found that the Peclet number, N(Pe) was not a strong function of the flow velocity at low flow rates through the bioreactor system, but its value decreased somewhat at an interstitial velocity greater than 0.03 cm/s. The tapered column bioreactor system showed a much better flow pattern of gas and liquid phases within the

  15. Evolution on qualities of leachate and landfill gas in the semi-aerobic landfill

    Institute of Scientific and Technical Information of China (English)

    HUANG Qifei; YANG Yufei; PANG Xiangrui; WANG Qi

    2008-01-01

    To study the characteristics of stabilization in semi-aerobic landfill, large-scale simulated landfill was constructed based on the semi-aerobic landfill theory. Consequently, the concentrations of chemical oxygen demand (COD), ammonia nitrogen, and nitrite nitrogen, and the pH value in leachate, as well as the component contents of landfill gas composition (methane, carbon dioxide, and oxygen) in landfill were regularly monitored for 52 weeks. The results showed that COD and ammonia concentrations declined rapidly and did not show the accumulating rule like anaerobic landfill, and remained at about 300 and 100 mg/L, respectively, after 48 weeks. Meanwhile, the descending rate reached 98.9% and 96.9%, respectively. Nitrate concentration increased rapidly after 24 weeks and fluctuated between 220-280 mg/L after 43 weeks. The pH values were below 7 during the first 8 weeks and after that leachates appeared to be alkaline. Carbon dioxide was the main composition in landfill gas and its concentration remained at a high level through the whole stabilization process. The average contents of carbon dioxide, oxygen, and methane varied between 19 vol.%-28 vol.%, 2 vol.%-8 vol.%, and 5 vol.%-13 vol.%, respectively. A relative equilibrium was reached after 48 weeks. The highest temperature in the landfill chamber could amount to 75.8 degrees centigrade.

  16. Development of a conceptual framework of holistic risk assessment - Landfill as a particular type of contaminated land.

    Science.gov (United States)

    Butt, T E; Javadi, A A; Nunns, M A; Beal, C D

    2016-11-01

    Landfills can be regarded as a particular type of contaminated land that has a potential to directly and indirectly pollute all of the four main spheres of the environment which are the lithosphere, atmosphere, hydrosphere and eventually adversely impact the biosphere. Therefore, environmental risk assessment of a landfill has to be more integrated and holistic by virtue of its nature of being a multidimensional pollutant source. Despite this, although various risk assessment approaches have been adopted for landfill waste disposal sites, there are still wide-ranging knowledge gaps and limitations which need to be addressed. One important knowledge gap and limitation of current risk assessment approaches is the inability to fully identify, categorise and aggregate all individual risks from all combinations of hazards, pathways and targets/receptors (e.g. water, air, soil and biota) in connection to a certain landfill leachate and yet at any stage of the landfill cycle. So such an approach is required that could not only integrate all possible characteristics of varying scenarios but also contain the ability to establish an overall risk picture, irrespective of the lifecycle stage of the landfill (e.g. planning stage/pre-operation, in-operation or post-operation/closed). One such approach to address the wide-breadth of landfill impact risks is by developing a more holistic risk assessment methodology, whose conceptual framework is presented in this paper for landfill leachate in a whole-system format. This conceptual framework does not only draw together various constituting factors and sub-factors of risk assessment in a logical sequence and categorical order, but also indicates the "what, why, when and how" outputs of and inputs to these factors and sub-factors can be useful. The framework is designed to identify and quantify a range of risks associated with all stages of the landfill lifecycle, and yet in a more streamlined, logical, categorical and integrated

  17. Photovoltaics on Landfills in Puerto Rico

    Energy Technology Data Exchange (ETDEWEB)

    Salasovich, J.; Mosey, G.

    2011-01-01

    The U.S. Environmental Protection Agency (EPA), in accordance with the RE-Powering America's Land initiative, selected the Commonwealth of Puerto Rico for a feasibility study of m0treAlables on several brownfield sites. The EPA defines a brownfield as 'a property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant.' All of the brownfields in this study are landfill sites. Citizens of Puerto Rico, city planners, and site managers are interested in redevelopment uses for landfills in Puerto Rico, which are particularly well suited for solar photovoltaic (PV) installation. The purpose of this report is to assess the landfills with the highest potential for possible solar PV installation and estimate cost, performance, and site impacts of three different PV options: crystalline silicon (fixed-tilt), crystalline silicon (single-axis tracking), and thin film (fixed-tilt). Each option represents a standalone system that can be sized to use an entire available site area. In addition, the report outlines financing options that could assist in the implementation of a system. The feasibility of PV systems installed on landfills is highly impacted by the available area for an array, solar resource, operating status, landfill cap status, distance to transmission lines, and distance to major roads. All of the landfills in Puerto Rico were screened according to these criteria in order to determine the sites with the greatest potential. Eight landfills were chosen for site visits based on the screening criteria and location. Because of time constraints and the fact that Puerto Rico is a relatively large island, the eight landfills for this visit were all located in the eastern half of the island. The findings from this report can be applied to landfills in the western half of the island. The economics of a potential PV system on landfills in Puerto Rico depend

  18. An innovative membrane bioreactor for methane biohydroxylation.

    Science.gov (United States)

    Pen, N; Soussan, L; Belleville, M-P; Sanchez, J; Charmette, C; Paolucci-Jeanjean, D

    2014-12-01

    In this study, a membrane bioreactor (MBR) was developed for efficient, safe microbial methane hydroxylation with Methylosinus trichosporium OB3b. This innovative MBR, which couples a bioreactor with two gas/liquid macroporous membrane contactors supplying the two gaseous substrates (methane and oxygen) was operated in fed-batch mode. The feasibility and the reproducibility of this new biohydroxylation process were first demonstrated. The mass transfer within this MBR was twice that observed in a batch reactor in similar conditions. The productivity reached with this MBR was 75±25mgmethanol(gdrycell)(-1)h(-1). Compared to the literature, this value is 35times higher than that obtained with the only other fed-batch membrane bioreactor reported, which was run with dense membranes, and is comparable to those obtained with bioreactors fed by bubble-spargers. However, in the latter case, an explosive gas mixture can be formed, a problem that is avoided with the MBR.

  19. In vivo bioreactors for mandibular reconstruction.

    Science.gov (United States)

    Tatara, A M; Wong, M E; Mikos, A G

    2014-12-01

    Large mandibular defects are difficult to reconstruct with good functional and aesthetic outcomes because of the complex geometry of craniofacial bone. While the current gold standard is free tissue flap transfer, this treatment is limited in fidelity by the shape of the harvested tissue and can result in significant donor site morbidity. To address these problems, in vivo bioreactors have been explored as an approach to generate autologous prefabricated tissue flaps. These bioreactors are implanted in an ectopic site in the body, where ossified tissue grows into the bioreactor in predefined geometries and local vessels are recruited to vascularize the developing construct. The prefabricated flap can then be harvested with vessels and transferred to a mandibular defect for optimal reconstruction. The objective of this review article is to introduce the concept of the in vivo bioreactor, describe important preclinical models in the field, summarize the human cases that have been reported through this strategy, and offer future directions for this exciting approach.

  20. A New Fluidized Bed Bioreactor Based on Diversion-Type Microcapsule Suspension for Bioartificial Liver Systems

    Science.gov (United States)

    Li, Jianzhou; Yu, Liang; Chen, Ermei; Zhu, Danhua; Zhang, Yimin; Li, LanJuan

    2016-01-01

    A fluidized bed bioreactor containing encapsulated hepatocytes may be a valuable alternative to a hollow fiber bioreactor for achieving the improved mass transfer and scale-up potential necessary for clinical use. However, a conventional fluidized bed bioreactor (FBB) operating under high perfusion velocity is incapable of providing the desired performance due to the resulting damage to cell-containing microcapsules and large void volume. In this study, we developed a novel diversion-type microcapsule-suspension fluidized bed bioreactor (DMFBB). The void volume in the bioreactor and stability of alginate/chitosan microcapsules were investigated under different flow rates. Cell viability, synthesis and metabolism functions, and expression of metabolizing enzymes at transcriptional levels in an encapsulated hepatocyte line (C3A cells) were determined. The void volume was significantly less in the novel bioreactor than in the conventional FBB. In addition, the microcapsules were less damaged in the DMFBB during the fluidization process as reflected by the results for microcapsule retention rates, swelling, and breakage. Encapsulated C3A cells exhibited greater viability and CYP1A2 and CYP3A4 activity in the DMFBB than in the FBB, although the increases in albumin and urea synthesis were less prominent. The transcription levels of several CYP450-related genes and an albumin-related gene were dramatically greater in cells in the DMFBB than in those in the FBB. Taken together, our results suggest that the DMFBB is a promising alternative for the design of a bioartificial liver system based on a fluidized bed bioreactor with encapsulated hepatocytes for treating patients with acute hepatic failure or other severe liver diseases. PMID:26840840

  1. A New Fluidized Bed Bioreactor Based on Diversion-Type Microcapsule Suspension for Bioartificial Liver Systems.

    Directory of Open Access Journals (Sweden)

    Juan Lu

    Full Text Available A fluidized bed bioreactor containing encapsulated hepatocytes may be a valuable alternative to a hollow fiber bioreactor for achieving the improved mass transfer and scale-up potential necessary for clinical use. However, a conventional fluidized bed bioreactor (FBB operating under high perfusion velocity is incapable of providing the desired performance due to the resulting damage to cell-containing microcapsules and large void volume. In this study, we developed a novel diversion-type microcapsule-suspension fluidized bed bioreactor (DMFBB. The void volume in the bioreactor and stability of alginate/chitosan microcapsules were investigated under different flow rates. Cell viability, synthesis and metabolism functions, and expression of metabolizing enzymes at transcriptional levels in an encapsulated hepatocyte line (C3A cells were determined. The void volume was significantly less in the novel bioreactor than in the conventional FBB. In addition, the microcapsules were less damaged in the DMFBB during the fluidization process as reflected by the results for microcapsule retention rates, swelling, and breakage. Encapsulated C3A cells exhibited greater viability and CYP1A2 and CYP3A4 activity in the DMFBB than in the FBB, although the increases in albumin and urea synthesis were less prominent. The transcription levels of several CYP450-related genes and an albumin-related gene were dramatically greater in cells in the DMFBB than in those in the FBB. Taken together, our results suggest that the DMFBB is a promising alternative for the design of a bioartificial liver system based on a fluidized bed bioreactor with encapsulated hepatocytes for treating patients with acute hepatic failure or other severe liver diseases.

  2. A New Fluidized Bed Bioreactor Based on Diversion-Type Microcapsule Suspension for Bioartificial Liver Systems.

    Science.gov (United States)

    Lu, Juan; Zhang, Xiaoqian; Li, Jianzhou; Yu, Liang; Chen, Ermei; Zhu, Danhua; Zhang, Yimin; Li, LanJuan

    2016-01-01

    A fluidized bed bioreactor containing encapsulated hepatocytes may be a valuable alternative to a hollow fiber bioreactor for achieving the improved mass transfer and scale-up potential necessary for clinical use. However, a conventional fluidized bed bioreactor (FBB) operating under high perfusion velocity is incapable of providing the desired performance due to the resulting damage to cell-containing microcapsules and large void volume. In this study, we developed a novel diversion-type microcapsule-suspension fluidized bed bioreactor (DMFBB). The void volume in the bioreactor and stability of alginate/chitosan microcapsules were investigated under different flow rates. Cell viability, synthesis and metabolism functions, and expression of metabolizing enzymes at transcriptional levels in an encapsulated hepatocyte line (C3A cells) were determined. The void volume was significantly less in the novel bioreactor than in the conventional FBB. In addition, the microcapsules were less damaged in the DMFBB during the fluidization process as reflected by the results for microcapsule retention rates, swelling, and breakage. Encapsulated C3A cells exhibited greater viability and CYP1A2 and CYP3A4 activity in the DMFBB than in the FBB, although the increases in albumin and urea synthesis were less prominent. The transcription levels of several CYP450-related genes and an albumin-related gene were dramatically greater in cells in the DMFBB than in those in the FBB. Taken together, our results suggest that the DMFBB is a promising alternative for the design of a bioartificial liver system based on a fluidized bed bioreactor with encapsulated hepatocytes for treating patients with acute hepatic failure or other severe liver diseases.

  3. Biofabrication of customized bone grafts by combination of additive manufacturing and bioreactor knowhow.

    Science.gov (United States)

    Costa, Pedro F; Vaquette, Cédryck; Baldwin, Jeremy; Chhaya, Mohit; Gomes, Manuela E; Reis, Rui L; Theodoropoulos, Christina; Hutmacher, Dietmar W

    2014-09-01

    This study reports on an original concept of additive manufacturing for the fabrication of tissue engineered constructs (TEC), offering the possibility of concomitantly manufacturing a customized scaffold and a bioreactor chamber to any size and shape. As a proof of concept towards the development of anatomically relevant TECs, this concept was utilized for the design and fabrication of a highly porous sheep tibia scaffold around which a bioreactor chamber of similar shape was simultaneously built. The morphology of the bioreactor/scaffold device was investigated by micro-computed tomography and scanning electron microscopy confirming the porous architecture of the sheep tibiae as opposed to the non-porous nature of the bioreactor chamber. Additionally, this study demonstrates that both the shape, as well as the inner architecture of the device can significantly impact the perfusion of fluid within the scaffold architecture. Indeed, fluid flow modelling revealed that this was of significant importance for controlling the nutrition flow pattern within the scaffold and the bioreactor chamber, avoiding the formation of stagnant flow regions detrimental for in vitro tissue development. The bioreactor/scaffold device was dynamically seeded with human primary osteoblasts and cultured under bi-directional perfusion for two and six weeks. Primary human osteoblasts were observed homogenously distributed throughout the scaffold, and were viable for the six week culture period. This work demonstrates a novel application for additive manufacturing in the development of scaffolds and bioreactors. Given the intrinsic flexibility of the additive manufacturing technology platform developed, more complex culture systems can be fabricated which would contribute to the advances in customized and patient-specific tissue engineering strategies for a wide range of applications.

  4. Thin film bioreactors in space

    Science.gov (United States)

    Hughes-Fulford, M.; Scheld, H. W.

    1989-01-01

    Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization, and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers an opportunity to learn more about basic biological systems with one inmportant variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would make it possible to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology.

  5. NASA Bioreactors Advance Disease Treatments

    Science.gov (United States)

    2009-01-01

    The International Space Station (ISS) is falling. This is no threat to the astronauts onboard, however, because falling is part of the ISS staying in orbit. The absence of gravity beyond the Earth s atmosphere is actually an illusion; at the ISS s orbital altitude of approximately 250 miles above the surface, the planet s gravitational pull is only 12-percent weaker than on the ground. Gravity is constantly pulling the ISS back to Earth, but the space station is also constantly traveling at nearly 18,000 miles per hour. This means that, even though the ISS is falling toward Earth, it is moving sideways fast enough to continually miss impacting the planet. The balance between the force of gravity and the ISS s motion creates a stable orbit, and the fact that the ISS and everything in it including the astronauts are falling at an equal rate creates the condition of weightlessness called microgravity. The constant falling of objects in orbit is not only an important principle in space, but it is also a key element of a revolutionary NASA technology here on Earth that may soon help cure medical ailments from heart disease to diabetes. In the mid-1980s, NASA researchers at Johnson Space Center were investigating the effects of long-term microgravity on human tissues. At the time, the Agency s shuttle fleet was grounded following the 1986 Space Shuttle Challenger disaster, and researchers had no access to the microgravity conditions of space. To provide a method for recreating such conditions on Earth, Johnson s David Wolf, Tinh Trinh, and Ray Schwarz developed that same year a horizontal, rotating device called a rotating wall bioreactor that allowed the growth of human cells in simulated weightlessness. Previously, cell cultures on Earth could only be grown two-dimensionally in Petri dishes, because gravity would cause the multiplying cells to sink within their growth medium. These cells do not look or function like real human cells, which grow three-dimensionally in

  6. Thin film bioreactors in space

    Science.gov (United States)

    Hughes-Fulford, M.; Scheld, H. W.

    Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers us an opportunity to learn more about basic biological systems with one important variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would enable us to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology.

  7. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Don Augenstein

    1999-01-11

    ''Conventional'' waste landfills emit methane, a potent greenhouse gas, in quantities such that landfill methane is a major factor in global climate change. Controlled landfilling is a novel approach to manage landfills for rapid completion of total gas generation, maximizing gas capture and minimizing emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated and brought to much earlier completion by improving conditions for biological processes (principally moisture levels) in the landfill. Gas recovery efficiency approaches 100% through use of surface membrane cover over porous gas recovery layers operated at slight vacuum. A field demonstration project's results at the Yolo County Central Landfill near Davis, California are, to date, highly encouraging. Two major controlled landfilling benefits would be the reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times than with conventional landfill practice. With the large amount of US landfill methane generated, and greenhouse potency of methane, better landfill methane control can play a substantial role in reduction of US greenhouse gas emissions.

  8. Phytoremediation of Landfill Leachate with Colocasia esculenta, Gynerum sagittatum and Heliconia psittacorum in Constructed Wetlands.

    Science.gov (United States)

    Madera-Parra, C A; Peña-Salamanca, E J; Peña, M R; Rousseau, D P L; Lens, P N L

    2015-01-01

    This study assessed the accumulation of Cd (II), Hg (II), Cr (VI) and Pb (II) in Gynerium sagittatum (Gs), Colocasia esculenta (Ce) and Heliconia psittacorum (He) planted in constructed wetlands treating synthetic landfill leachate. Sixteen bioreactors were operated in two experimental blocks. Metal concentrations in the influent and effluent; root, stem, branch and leaves of plants were analysed, as well as COD, N-NH4+, TKN, T, pH, ORP, DO, and EC. Average removal efficiencies of COD, TKN and NH4+-N were 66, 67 and 72%, respectively and heavy metal removal ranged from 92 to 98% in all units. Cr (VI) was not detected in any effluent sample. The bioconcentration factors (BCF) were 10(0) -10(2). The BCF of Cr (VI) was the lowest: 0.59 and 2.5 (L kg(-1)) for Gs and He respectively; whilst Cd (II) had the highest (130-135 L kg(-1)) for Gs. Roots showed a higher metal content than shoots. Translocation factors (TF) were lower, He was the plant exhibiting TFs>1 for Pb (II), Cr (T) and Hg (II) and 0.4-0.9 for Cd (II) and Cr (VI). The evaluated plants demonstrate their suitability for phytoremediation of landfill leachate and all of them can be categorized as metals accumulators.

  9. Removal of Refractory Organics from Biologically Treated Landfill Leachate by Microwave Discharge Electrodeless Lamp Assisted Fenton Process

    Directory of Open Access Journals (Sweden)

    Jiuyi Li

    2015-01-01

    Full Text Available Biologically treated leachate usually contains considerable amount of refractory organics and trace concentrations of xenobiotic pollutants. Removal of refractory organics from biologically treated landfill leachate by a novel microwave discharge electrodeless lamp (MDEL assisted Fenton process was investigated in the present study in comparison to conventional Fenton and ultraviolet Fenton processes. Conventional Fenton and ultraviolet Fenton processes could substantially remove up to 70% of the refractory organics in a membrane bioreactor treated leachate. MDEL assisted Fenton process achieved excellent removal performance of the refractory components, and the effluent chemical oxygen demand concentration was lower than 100 mg L−1. Most organic matters were transformed into smaller compounds with molecular weights less than 1000 Da. Ten different polycyclic aromatic hydrocarbons were detected in the biologically treated leachate, most of which were effectively removed by MDEL-Fenton treatment. MDEL-Fenton process provides powerful capability in degradation of refractory and xenobiotic organic pollutants in landfill leachate and could be adopted as a single-stage polishing process for biologically treated landfill leachate to meet the stringent discharge limit.

  10. A simulation analysis of the migration and transformation of pollutants contained in landfill leachate

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-qi; TIAN Kai-ming; QI Yong-qiang; CHEN Jia-jun; WANG Ya-nan

    2003-01-01

    A dynamic composite model for a soil-water system that can be used to simulate the movement of leachate from a landfill. The composite model includes nine sub-models that trace water movement and the migration and transformation of five pollutants(organic N, NH4- ,NO3- , NO2- , and Cl- ) in saturated and unsaturated soil. The model to simulate the movement of leachate from a landfill in Laogang Town,Shanghai City was used. In this application, the values for the model parameters were obtained by performing a laboratory simulation experiment of water movement and pollutant migration and transformation in soil colunms. Soil and leachate obtained from the landfill site and its vicinity were used in the laboratory experiments. The model was then used to simulate leachate movement and pollutant activity during the ten-year period when the landfill was in operation and in the twenty-year period following its closure. The simulation results revealed that the leachate migrated into the groundwater at the rate of 90-100 meters per year. This model can be applied in the design of future landfills in China for the purpose of assessing and forecasting leachate plumes.

  11. LCA and economic evaluation of landfill leachate and gas technologies

    DEFF Research Database (Denmark)

    Damgaard, Anders; Manfredi, Simone; Merrild, Hanna Kristina

    2011-01-01

    improvements for most impact categories. Global warming went from an impact of 0.1 person equivalent (PE) for the dump to −0.05 PE for the best design. Similar improvements were found for photochemical ozone formation (0.02 PE to 0.002 PE) and stratospheric ozone formation (0.04 PE to 0.001 PE).For the toxic...... through emissions of treated wastewater to surface waters.The largest environmental improvement with regard to the direct cost of the landfill was the capping and leachate treatment system. The capping, though very cheap to establish, gave a huge benefit in lowered impacts, the leachate collection system...

  12. Containerized Wetland Bioreactor Evaluated for Perchlorate and Nitrate Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Dibley, V R; Krauter, P W

    2004-12-02

    The U.S. Department of Energy (DOE) and Lawrence Livermore Laboratory (LLNL) designed and constructed an innovative containerized wetlands (bioreactor) system that began operation in November 2000 to biologically degrade perchlorate and nitrate under relatively low-flow conditions at a remote location at Site 300 known as Building 854. Since initial start-up, the system has processed over 3,463,000 liters of ground water and treated over 38 grams of perchlorate and 148 kilograms of nitrate. Site 300 is operated by the University of California as a high-explosives and materials testing facility supporting nuclear weapons research. The 11-square mile site located in northern California was added to the NPL in 1990 primarily due to the presence of elevated concentrations of volatile organic compounds (VOCs) in ground water. At the urging of the regulatory agencies, perchlorate was looked for and detected in the ground water in 1999. VOCs, nitrate and perchlorate were released into the soil and ground water in the Building 854 area as the result of accidental leaks during stability testing of weapons or from waste discharge practices that are no longer permitted at Site 300. Design of the wetland bioreactors was based on earlier studies showing that indigenous chlorate-respiring bacteria could effectively degrade perchlorate into nontoxic concentrations of chlorate, chlorite, oxygen, and chloride. Studies also showed that the addition of organic carbon would enhance microbial denitrification. Early onsite testing showed acetic acid to be a more effective carbon source than dried leaf matter, dried algae, or milk replacement starter; a nutrient and carbon source used in a Department of Defense phytoremediation demonstration. No inocula were added to the system. Groundwater was allowed to circulate through the bioreactor for three weeks to acclimate the wetland plants and to build a biofilm from indigenous flora. Using solar energy, ground water is pumped into granular

  13. Environmental impact assessment on the construction and operation of municipal solid waste sanitary landfills in developing countries: China case study

    DEFF Research Database (Denmark)

    Yang, Na; Damgaard, Anders; Lü, Fan

    2014-01-01

    An inventory of material and energy consumption during the construction and operation (C&O) of a typical sanitary landfill site in China was calculated based on Chinese industrial standards for landfill management and design reports. The environmental impacts of landfill C&O were evaluated through...... life cycle assessment (LCA). The amounts of materials and energy used during this type of undertaking in China are comparable to those in developed countries, except that the consumption of concrete and asphalt is significantly higher in China. A comparison of the normalized impact potential between...... of mineral materials. To test the influences of different landfill C&O approaches on environmental impacts, six baseline alternatives were assessed through sensitivity analysis. If geomembranes and geonets were utilized to replace daily and intermediate soil covers and gravel drainage systems, respectively...

  14. Landfills and the waste act implementation - what has changed?

    CSIR Research Space (South Africa)

    Oelofse, Suzanna HH

    2013-10-01

    Full Text Available The introduction of landfill permits by Section 20 of the Environment Conservation Act, 1989, resulted in the development of the Minimum Requirements series of documents to guide waste disposal to landfill. The promulgation of the National...

  15. Feasibility analysis of remedial scheme of Qilongcun landfill

    Institute of Scientific and Technical Information of China (English)

    LUO Yun-ju; LIU Dong-yan; LIU Xin-rong; LI Xiu-lan

    2006-01-01

    Based on hydro-geological of Qilongcun landfill, the transportation mathematical model of leachat was established. The boundaries conditions and replenishment of model were determined. The leachate COD density and the water level were simulated, and the model was identified, and then the right model was defined. The right model was used to simulate leachate COD density in the interior, exterior, and peripheral of landfill. The results show that the COD densities are not high. The pollution is slight in the interior of landfill and is little in the exterior of landfill. They are proving the overburden on top of landfill and drain around the landfill is right. The max. density on the south of landfill shows it is scientific that the cisterns are building on the south of landfill. The paper shows the remediation scheme is feasible.

  16. EVALUATION OF COLLIER COUNTY, FLORIDA LANDFILL MINING DEMONSTRATION

    Science.gov (United States)

    This report describes the landfill mining process as demonstrated under the U.S. EPA, Risk Reduction Engineering Laboratory's Municipal Waste Innovative Technology Evaluation (MITE) Program by the Collier County (Florida) Solid Waste Management Department. Landfill mining is the ...

  17. Landfills as a biorefinery to produce biomass and capture biogas.

    Science.gov (United States)

    Bolan, N S; Thangarajan, R; Seshadri, B; Jena, U; Das, K C; Wang, H; Naidu, R

    2013-05-01

    While landfilling provides a simple and economic means of waste disposal, it causes environmental impacts including leachate generation and greenhouse gas (GHG) emissions. With the introduction of gas recovery systems, landfills provide a potential source of methane (CH4) as a fuel source. Increasingly revegetation is practiced on traditionally managed landfill sites to mitigate environmental degradation, which also provides a source of biomass for energy production. Combustion of landfill gas for energy production contributes to GHG emission reduction mainly by preventing the release of CH4 into the atmosphere. Biomass from landfill sites can be converted to bioenergy through various processes including pyrolysis, liquefaction and gasification. This review provides a comprehensive overview on the role of landfills as a biorefinery site by focusing on the potential volumes of CH4 and biomass produced from landfills, the various methods of biomass energy conversion, and the opportunities and limitations of energy capture from landfills.

  18. Artificial sweeteners as potential tracers of municipal landfill leachate.

    Science.gov (United States)

    Roy, James W; Van Stempvoort, Dale R; Bickerton, Greg

    2014-01-01

    Artificial sweeteners are gaining acceptance as tracers of human wastewater in the environment. The 3 artificial sweeteners analyzed in this study were detected in leachate or leachate-impacted groundwater at levels comparable to those of untreated wastewater at 14 of 15 municipal landfill sites tested, including several closed for >50 years. Saccharin was the dominant sweetener in old (pre-1990) landfills, while newer landfills were dominated by saccharin and acesulfame (introduced 2 decades ago; dominant in wastewater). Cyclamate was also detected, but less frequently. A case study at one site illustrates the use of artificial sweeteners to identify a landfill-impacted groundwater plume discharging to a stream. The study results suggest that artificial sweeteners can be useful tracers for current and legacy landfill contamination, with relative abundances of the sweeteners potentially providing diagnostic ability to distinguish different landfills or landfill cells, including crude age-dating, and to distinguish landfill and wastewater sources.

  19. Modeling of hydrodynamics in hollow fiber membrane bioreactor for mammalian cells cultivation

    Directory of Open Access Journals (Sweden)

    N. V. Menshutina

    2016-01-01

    Full Text Available The mathematical modelling in CFD-packages are powerfull instrument for design and calculation of any engineering tasks. CFD-package contains the set of programs that allow to model the different objects behavior based on the mathematical lows. ANSYS Fluent are widely used for modelling of biotechnological and chemical-technological processes. This package is convenient to describe their hydrodynamics. As cell cultivation is one of the actual scientific direction in modern biotechnology ANSYS Fluent was used to create the model of hollow fiber membrane bioreactor. The fibers are hollow cylindrical membrane to be used for cell cultivation. The criterion of process effectiveness for cell growth is full filling of the membrane surface by cells in the bioreactor. While the cell growth the fiber permeability is decreased which effects to feed flow through membrane pores. The specific feature of this process is to ensure such feed flow to deliver the optimal nutrition for the cells on the external membrane surface. The velocity distribution inside the fiber and in all bioreactor as a whole has been calculated based on mass an impulse conservation equations taking into account the mathematical model assumptions. The hydrodynamics analysis in hollow fiber membrane bioreactor is described by the three-dimensional model created in ANSYS Fluent. The specific features of one membrane model are considered and for whole bioreactor too.

  20. A Versatile Bioreactor for Dynamic Suspension Cell Culture. Application to the Culture of Cancer Cell Spheroids.

    Science.gov (United States)

    Massai, Diana; Isu, Giuseppe; Madeddu, Denise; Cerino, Giulia; Falco, Angela; Frati, Caterina; Gallo, Diego; Deriu, Marco A; Falvo D'Urso Labate, Giuseppe; Quaini, Federico; Audenino, Alberto; Morbiducci, Umberto

    2016-01-01

    A versatile bioreactor suitable for dynamic suspension cell culture under tunable shear stress conditions has been developed and preliminarily tested culturing cancer cell spheroids. By adopting simple technological solutions and avoiding rotating components, the bioreactor exploits the laminar hydrodynamics establishing within the culture chamber enabling dynamic cell suspension in an environment favourable to mass transport, under a wide range of tunable shear stress conditions. The design phase of the device has been supported by multiphysics modelling and has provided a comprehensive analysis of the operating principles of the bioreactor. Moreover, an explanatory example is herein presented with multiphysics simulations used to set the proper bioreactor operating conditions for preliminary in vitro biological tests on a human lung carcinoma cell line. The biological results demonstrate that the ultralow shear dynamic suspension provided by the device is beneficial for culturing cancer cell spheroids. In comparison to the static suspension control, dynamic cell suspension preserves morphological features, promotes intercellular connection, increases spheroid size (2.4-fold increase) and number of cycling cells (1.58-fold increase), and reduces double strand DNA damage (1.5-fold reduction). It is envisioned that the versatility of this bioreactor could allow investigation and expansion of different cell types in the future.

  1. Barometric pumping of burial trench soil gases into the atmosphere at the 740-G Sanitary Landfill

    Energy Technology Data Exchange (ETDEWEB)

    Wyatt, D.E.; Pirkle, R.J.; Masdea, D.J.

    1992-12-01

    In 1991, a soil gas survey was performed at the Savannah River Site Sanitary Landfill as part of the characterization efforts required under the integrated Resource Conservation and Recovery Act (RCRA) Facility Investigation and Comprehensive Environmental Resource Conservation and Recovery Act (CERCLA) Remedial Investigation (RFI/RI) program. This report details the findings of this survey, which identified several areas of the landfill that were releasing volatile organic compounds to the atmosphere at levels exceeding regulatory standards. Knowledge of the rates of VOC outgassing is necessary to protect site workers, provide input into the human health and environmental risk assessment documents and provide input into the remedial design scenario.

  2. Advanced microscale bioreactor system: a representative scale-down model for bench-top bioreactors.

    Science.gov (United States)

    Hsu, Wei-Ting; Aulakh, Rigzen P S; Traul, Donald L; Yuk, Inn H

    2012-12-01

    In recent years, several automated scale-down bioreactor systems have been developed to increase efficiency in cell culture process development. ambr™ is an automated workstation that provides individual monitoring and control of culture dissolved oxygen and pH in single-use, stirred-tank bioreactors at a working volume of 10-15 mL. To evaluate the ambr™ system, we compared the performance of four recombinant Chinese hamster ovary cell lines in a fed-batch process in parallel ambr™, 2-L bench-top bioreactors, and shake flasks. Cultures in ambr™ matched 2-L bioreactors in controlling the environment (temperature, dissolved oxygen, and pH) and in culture performance (growth, viability, glucose, lactate, Na(+), osmolality, titer, and product quality). However, cultures in shake flasks did not show comparable performance to the ambr™ and 2-L bioreactors.

  3. Hydrodynamics of an Electrochemical Membrane Bioreactor

    Science.gov (United States)

    Wang, Ya-Zhou; Wang, Yun-Kun; He, Chuan-Shu; Yang, Hou-Yun; Sheng, Guo-Ping; Shen, Jin-You; Mu, Yang; Yu, Han-Qing

    2015-05-01

    An electrochemical membrane bioreactor (EMBR) has recently been developed for energy recovery and wastewater treatment. The hydrodynamics of the EMBR would significantly affect the mass transfers and reaction kinetics, exerting a pronounced effect on reactor performance. However, only scarce information is available to date. In this study, the hydrodynamic characteristics of the EMBR were investigated through various approaches. Tracer tests were adopted to generate residence time distribution curves at various hydraulic residence times, and three hydraulic models were developed to simulate the results of tracer studies. In addition, the detailed flow patterns of the EMBR were acquired from a computational fluid dynamics (CFD) simulation. Compared to the tank-in-series and axial dispersion ones, the Martin model could describe hydraulic performance of the EBMR better. CFD simulation results clearly indicated the existence of a preferential or circuitous flow in the EMBR. Moreover, the possible locations of dead zones in the EMBR were visualized through the CFD simulation. Based on these results, the relationship between the reactor performance and the hydrodynamics of EMBR was further elucidated relative to the current generation. The results of this study would benefit the design, operation and optimization of the EMBR for simultaneous energy recovery and wastewater treatment.

  4. Hydrophobic organic chemicals (HOCs) removal from biologically treated landfill leachate by powder-activated carbon (PAC), granular-activated carbon (GAC) and biomimetic fat cell (BFC).

    Science.gov (United States)

    Liyan, Song; Youcai, Zhao; Weimin, Sun; Ziyang, Lou

    2009-04-30

    Biological pretreatment efficiently remove organic matter from landfill leachate, but further removal of refractory hydrophobic organic chemicals (HOCs) is hard even with advanced treatment. In this work, three-stage-aged refuse bioreactor (ARB) efficiently removed chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of fresh leachate produced in Shanghai laogang landfill, from 8603 to 451 mg L(-1) and 1368 to 30 mg L(-1), respectively. In downstream treatment, 3 g L(-1) powder-activated carbon (PAC), granular-activated carbon (GAC) and biomimetic fat cell (BFC) removed 89.2, 73.4 and 81.1% HOCs, but only 24.6, 19.1 and 8.9% COD, respectively. Through the specific HOCs accumulation characteristics of BFC, about 11.2% HOCs with low molecular weight (effluent exhibited a wide molecular weight distribution (34-514,646 Da). These constitutes are derived from both autochthonous and allochthonous matters as well as biological activities.

  5. Nitrogen Removal from Landfill Leachate by Microalgae

    Directory of Open Access Journals (Sweden)

    Sérgio F. L. Pereira

    2016-11-01

    Full Text Available Landfill leachates result from the degradation of solid residues in sanitary landfills, thus presenting a high variability in terms of composition. Normally, these effluents are characterized by high ammoniacal-nitrogen (N–NH4+ concentrations, high chemical oxygen demands and low phosphorus concentrations. The development of effective treatment strategies becomes difficult, posing a serious problem to the environment. Phycoremediation appears to be a suitable alternative for the treatment of landfill leachates. In this study, the potential of Chlorella vulgaris for biomass production and nutrients (mainly nitrogen and phosphorus removal from different compositions of a landfill leachate was evaluated. Since microalgae also require phosphorus for their growth, different loads of this nutrient were evaluated, giving the following N:P ratios: 12:1, 23:1 and 35:1. The results have shown that C. vulgaris was able to grow in the different leachate compositions assessed. However, microalgal growth was higher in the cultures presenting the lowest N–NH4+ concentration. In terms of nutrients uptake, an effective removal of N–NH4+ and phosphorus was observed in all the experiments, especially in those supplied with phosphorus. Nevertheless, N–NO3− removal was considered almost negligible. These promising results constitute important findings in the development of a bioremediation technology for the treatment of landfill leachates.

  6. Ecotoxicological diagnosis of a sealed municipal landfill.

    Science.gov (United States)

    Hernández, A J; Bartolomé, C; Pérez-Leblic, M I; Rodríguez, J; Alvarez, J; Pastor, J

    2012-03-01

    Assessing the environmental impact of a soil-topped landfill requires an accurate ecotoxicological diagnosis. This paper describes various diagnostic protocols for this purpose and their application to a real case: the urban solid waste (USW) municipal landfill of Getafe (Madrid, Spain). After their initial sealing with soil from the surroundings about 20 years ago, most USW landfills in the autonomous community of Madrid have continued to receive waste. This has hindered precise assessment of their impact on their environment and affected ecosystems. The procedure proposed here overcomes this problem by assessing the situation in edaphic, aquatic and ecological terms. The present study focused on the most influential soil variables (viz. salinity due largely to the presence of anions, and heavy metals and organic compounds). These variables were also determined in surface waters of the wetland most strongly affected by leachates running down landfill slopes. Determinations included the characterization of plant communities and microbial biodiversity. The study was supplemented with a bioassay under controlled conditions in pots containing soil contaminated with variable concentrations of Zn (as ZnCl(2)) intended to assess ecochemical actions in a population of Bromus rubens, which grows profusely in the landfill. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Nitrogen Removal from Landfill Leachate by Microalgae

    Science.gov (United States)

    Pereira, Sérgio F. L.; Gonçalves, Ana L.; Moreira, Francisca C.; Silva, Tânia F. C. V.; Vilar, Vítor J. P.; Pires, José C. M.

    2016-01-01

    Landfill leachates result from the degradation of solid residues in sanitary landfills, thus presenting a high variability in terms of composition. Normally, these effluents are characterized by high ammoniacal-nitrogen (N–NH4+) concentrations, high chemical oxygen demands and low phosphorus concentrations. The development of effective treatment strategies becomes difficult, posing a serious problem to the environment. Phycoremediation appears to be a suitable alternative for the treatment of landfill leachates. In this study, the potential of Chlorella vulgaris for biomass production and nutrients (mainly nitrogen and phosphorus) removal from different compositions of a landfill leachate was evaluated. Since microalgae also require phosphorus for their growth, different loads of this nutrient were evaluated, giving the following N:P ratios: 12:1, 23:1 and 35:1. The results have shown that C. vulgaris was able to grow in the different leachate compositions assessed. However, microalgal growth was higher in the cultures presenting the lowest N–NH4+ concentration. In terms of nutrients uptake, an effective removal of N–NH4+ and phosphorus was observed in all the experiments, especially in those supplied with phosphorus. Nevertheless, N–NO3− removal was considered almost negligible. These promising results constitute important findings in the development of a bioremediation technology for the treatment of landfill leachates. PMID:27869676

  8. Nitrogen Removal from Landfill Leachate by Microalgae.

    Science.gov (United States)

    Pereira, Sérgio F L; Gonçalves, Ana L; Moreira, Francisca C; Silva, Tânia F C V; Vilar, Vítor J P; Pires, José C M

    2016-11-17

    Landfill leachates result from the degradation of solid residues in sanitary landfills, thus presenting a high variability in terms of composition. Normally, these effluents are characterized by high ammoniacal-nitrogen (N-NH₄⁺) concentrations, high chemical oxygen demands and low phosphorus concentrations. The development of effective treatment strategies becomes difficult, posing a serious problem to the environment. Phycoremediation appears to be a suitable alternative for the treatment of landfill leachates. In this study, the potential of Chlorella vulgaris for biomass production and nutrients (mainly nitrogen and phosphorus) removal from different compositions of a landfill leachate was evaluated. Since microalgae also require phosphorus for their growth, different loads of this nutrient were evaluated, giving the following N:P ratios: 12:1, 23:1 and 35:1. The results have shown that C. vulgaris was able to grow in the different leachate compositions assessed. However, microalgal growth was higher in the cultures presenting the lowest N-NH₄⁺ concentration. In terms of nutrients uptake, an effective removal of N-NH₄⁺ and phosphorus was observed in all the experiments, especially in those supplied with phosphorus. Nevertheless, N-NO₃(-) removal was considered almost negligible. These promising results constitute important findings in the development of a bioremediation technology for the treatment of landfill leachates.

  9. Engineering geology of landfill gas migration

    Energy Technology Data Exchange (ETDEWEB)

    Tingley, A.C.

    1990-01-01

    This thesis is divided into five chapters: Part one is an introduction to landfill gas, and why it is considered to be a problem. The subject of the migration of the gas is taken further with an examination of the state of art with respect to theories of gas transport mechanisms. A description of work which has previously been carried out upon real soils and landfill sites is included. In part two the technique developed in this research to enable a laboratory examination of real soils is discussed. Experiments are then described which form part of the landfill gas monitoring programme in the field. The whole group of data, collected at a variety of sites, included measurements of meteorological conditions, ground pressures on and off the landfill, and ground gas concentrations. The observations were used to construct a model of ground gas interchange between the landfill and surrounding land. Field pumping trials have been used to confirm these findings. The third part of the thesis is an examination of case histories, presented in order of detail available for each; results of a survey carried out between other county councils in England, and then the results of a survey in the county of Kent. Finally there is a presentation of the detailed histories of the waste disposal sites which have been examined for the purposes of this research. (Author).

  10. Trace Gas Emission from in-Situ Denitrifying Bioreactors

    Science.gov (United States)

    Pluer, W.; Walter, M. T.; Geohring, L.

    2014-12-01

    Despite decades of concerted effort to mitigate nonpoint source nitrate (NO3-) pollution from agricultural lands, these efforts have not been sufficient to arrest eutrophication. A primary process for removing excess NO3- from water is denitrification, where denitrifying bacteria use NO3- for respiration in the absence of oxygen. Denitrification results in reduced forms of nitrogen, often dinitrogen gas (N2) but also nitrous oxide (N2O), an aggressive greenhouse gas. A promising solution to NO3- pollution is to intercept agricultural discharges with denitrifying bioreactors (DNBRs). DNBRs provide conditions ideal for denitrifiers: an anaerobic environment, sufficient organic matter, and excess NO3-. These conditions are also ideal for methanogens, which produce methane (CH4), another harmful trace gas. While initial results from bioreactor studies show that they can cost-effectively remove NO3-, trace gas emissions are an unintended consequence. This study's goal was to determine how bioreactor design promotes denitrification while limiting trace gas production. Reactor inflow and outflow water samples were tested for nutrients, including NO3-, and dissolved inflow and outflow gas samples were tested for N2O and CH4. NO3- reduction and trace gas production were evaluated at various residence times, pHs, and inflow NO3- concentrations in field and lab-scale reactors. Low NO3- reduction indicated conditions that stressed denitrifying bacteria while high reductions indicated designs that optimized pollutant treatment for water quality. Several factors influenced high N2O, suggesting non-ideal conditions for the final step of complete denitrification. High CH4 emissions pointed to reactor media choice for discouraging methanogens, which may remove competition with denitrifiers. It is critical to understand all of potential impacts that DNBRs may have, which means identifying processes and design specifications that may affect them.

  11. Gas Transport Parameters for Landfill Final Cover Soil: Measurements and Model Modification by Dry Bulk Density

    Science.gov (United States)

    Wickramarachchi, P. N.; Kawamoto, K.; Hamamoto, S.; Nagamori, M.; Moldrup, P.; Komatsu, T.

    2011-12-01

    Landfill sites have been emerging in greenhouse warming scenarios as a significant source of atmospheric methane (CH4). Until recently, landfill management strategies have mainly addressed the problem of preventing groundwater contamination and reduction of leachate generation. Being one of the largest sources of anthropogenic CH4 emission, the final cover system should also be designed for minimizing the greenhouse gases migration into the atmosphere or the areas surrounding the landfill while securing the hydraulic performance. Compared to the intensive research efforts on hydraulic performances of landfill final cover soil, few studies about gas transport characteristics of landfill cover soils have been done. However, recent soil-gas studies implied that the effects of soil physical properties such as bulk density (i.e., compaction level), soil particle size are key parameters to understand landfill gaseous performance. The gas exchange through the final cover soils is controlled by advective and diffusive gas transport. Air permeability (ka) governs the advective gas transport while the soil-gas diffusion coefficient (Dp) governs diffusive gas transport. In this study, the effects of compaction level and particle size fraction effects on ka and Dp for landfill final cover soil was investigated. The disturbed soil samples were taken from landfill final cover in Japan. A compaction tests were performed for the soil samples with two different size fractions (content , the soil samples were repacked into soil cores (i.d. 15-cm, length 12-cm, 2120 cm3) at two different compaction levels [(MP):2700 kN/m2 and (SP):600 kN/m2]. After the compaction tests, ka and Dp were measured and then samples were saturated and subsequently drained at different soil-water matric potential of 0.98, 2.94, 9.81, 1235 kPa and with air-dried and oven-dried conditions. Results showed that measured Dp and ka values for the coarser (content. Further, compaction effort was much significant

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

  13. EXPERIMENTAL STUDY ON THE GAS-LIQUID FLOW IN THE MEMBRANE MICROPORE AERATION BIOREACTOR

    Directory of Open Access Journals (Sweden)

    DONG LIU

    2008-12-01

    Full Text Available Particle Image Velocimetry (PIV has been developed to measure the typical two-phase flow of various work conditions in Membrane Micropore Aeration Bioreactor (MMAB. The fluid phase is separated out using image processing techniques, which provides accurate measurements for the Bioreactor’s flow field, and makes it possible for quantitative analysis of the momentum exchange, heat exchange and the process of micro-admixture. The experimental method PIV used in this paper can preferably measure the complex flow in the reactor and initiates a new approach for the bioreactor design which mainly depends on experience at present.

  14. NUMERICAL SIMULATION BY COMPUTATIONAL FLUID DYNAMICS AND EXPERIMENTAL STUDY ON STIRRED BIOREACTOR WITH PUNCHED IMPELLER

    Institute of Scientific and Technical Information of China (English)

    WANG Yu; HE Pingting; YE Hong; XIN Zhihong

    2007-01-01

    Instantaneous flow field and temperature field of the two-phase fluid are measured by particle image velocimetry (PIV) and steady state method during the state of onflow. A turbulent two-phase fluid model of stirred bioreactor with punched impeller is established by the computational fluid dynamics (CFD), using a rotating coordinate system and sliding mesh to describe the relative motion between impeller and baffles. The simulation and experiment results of flow and temperature field prove their warps are less than 10% and the mathematic model can well simulate the fields, which will also provide the study on optimized-design and scale-up of bioreactors with reference value.

  15. Pathways of sulfide oxidation by haloalkaliphilic bacteria in limited-oxygen gas lift bioreactors.

    Science.gov (United States)

    Klok, Johannes B M; van den Bosch, Pim L F; Buisman, Cees J N; Stams, Alfons J M; Keesman, Karel J; Janssen, Albert J H

    2012-07-17

    Physicochemical processes, such as the Lo-cat and Amine-Claus process, are commonly used to remove hydrogen sulfide from hydrocarbon gas streams such as landfill gas, natural gas, and synthesis gas. Biodesulfurization offers environmental advantages, but still requires optimization and more insight in the reaction pathways and kinetics. We carried out experiments with gas lift bioreactors inoculated with haloalkaliphilic sulfide-oxidizing bacteria. At oxygen-limiting levels, that is, below an O(2)/H(2)S mole ratio of 1, sulfide was oxidized to elemental sulfur and sulfate. We propose that the bacteria reduce NAD(+) without direct transfer of electrons to oxygen and that this is most likely the main route for oxidizing sulfide to elemental sulfur which is subsequently oxidized to sulfate in oxygen-limited bioreactors. We call this pathway the limited oxygen route (LOR). Biomass growth under these conditions is significantly lower than at higher oxygen levels. These findings emphasize the importance of accurate process control. This work also identifies a need for studies exploring similar pathways in other sulfide oxidizers such as Thiobacillus bacteria.

  16. Partial Control of a Continuous Bioreactor: Application to an Anaerobic System for Heavy Metal Removal

    Directory of Open Access Journals (Sweden)

    M. I. Neria-González

    2016-01-01

    Full Text Available This work presents a control strategy for a continuous bioreactor for heavy metal removal. For this aim, regulation of the sulfate concentration, which is considered the measured and controlled state variable, allowed diminishing the cadmium concentration in the bioreactor, where the corresponding controller was designed via nonlinear bounded function. Furthermore, a nonlinear controllability analysis was done, which proved the closed-loop instability of the inner or uncontrolled dynamics of the bioreactor. A mathematical model, experimentally corroborated for cadmium removal, was employed as a benchmark for the proposed controller. Numerical experiments clearly illustrated the successful implementation of this methodology; therefore, cadmium removal amounted to more than 99%, when the initial cadmium concentration was up to 170 mg/L in continuous operating mode.

  17. An Experimental Study on the Treating River Sewage with New Bioreactor

    Institute of Scientific and Technical Information of China (English)

    Jiang Fan; Chen Weiping; Zhang Tao

    2007-01-01

    A new bioreactor on the basis of a dynamic fluidized bed was designed, which combines advantages of the fluidized bed and a biological contactor. The experiments of start-up, normal operation and parameter adjustment are carried out. The results show that the bioreactor can be quickly started up in the condition that the fill is 50%, the hydraulic retention time is 72 min, aerate speed is 2.5 m3/h, rotation-cage rotated speed is 1.5 r/min, and the removal rates of chemical oxygen demand (CODCr)and Ammonia nitrogen (NH3-N) are 75.34% and 80.98% respectively. The influence of the operation parameter on removal rates of the bioreactor is analyzed, and an appropriate operation parameter is provided.

  18. Toxic organic micro-pollutants removal mechanisms in long-term operated membrane bioreactor treating municipal solid waste leachate.

    Science.gov (United States)

    Boonyaroj, Varinthorn; Chiemchaisri, Chart; Chiemchaisri, Wilai; Theepharaksapan, Suthida; Yamamoto, Kazuo

    2012-06-01

    The performance of two-stage membrane bioreactor (MBR) in term of toxic organic micro-pollutants removal was continuously monitored for 300 days under long sludge age condition. The phenolic compounds and phthalic acid esters (PAEs) in landfill leachate and treated water from MBR unit were quantified by solid phase extraction and gas chromatography-mass spectrometry. Priority pollutants in landfill leachate were phenolics and their degradation products i.e. 4-methyl-2,6-di-tert-butylphenol, bisphenol A at higher concentrations above 100 μg/l, PAEs i.e. dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, di-n-octyl phthalate, and di (2-ethylhexyl) phthalate. It was found that MBR could remove phenolic compounds and PAEs by 77-96%. Biodegradation and adsorption mechanisms were responsible for their removals in MBR. Additionally, the retention of compounds during filtration through the fouled membrane was also found significant. This research shows that the removal of organic micro-pollutants in landfill leachate was improved under higher biomass concentration and longer sludge age conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Washington Closure Hanford Report of Settlement Monitoring of the ERDF Landfill

    Energy Technology Data Exchange (ETDEWEB)

    J. T. Cameron

    2008-07-30

    This report summarizes the results of the ERDF Settlement Monitoring Program conducted between August 9, 2007, and April 29, 2008, on the 35-foot and 70-foot levels of the ERDF landfill. The purpose of this monitoring program was to verify that the materials already placed under the 35-foot and 70-foot levels satisfy the settlement criteria of the conceptual cap design.

  20. Long-term performance of landfill covers - results of lysimeter test fields in Bavaria (Germany).

    Science.gov (United States)

    Henken-Mellies, Wolf-Ulrich; Schweizer, Andreas

    2011-01-01

    A comprehensive study was conducted to examine the performance and possible changes in the effectiveness of landfill surface covers. Three different profiles of mineral landfill caps were examined. The results of precipitation and flow measurements show distinct seasonal differences which are typical for middle-European climatic conditions. In the case of the simple landfill cap design consisting of a thick layer of loamy sand, approximately 100-200 L m(-2) of annual seepage into the landfill body occurs during winter season. The three-layer systems of the two other test fields performed much better. Most of the water which percolated through the top soil profile drained sideways in the drainage layer. Only 1-3% of precipitation percolated through the sealing layer. The long-term effectiveness of the mineral sealing layer depended on the ability of the top soil layer to protect it from critical loss of soil water/critical increase of suction. In dry summers there was even a loss in soil water content at the base of the 2.0 m thick soil cover. The results of this study demonstrate the importance of the long-term aspect when assessing the effectiveness of landfill covers: The hydraulic conductivity at the time of construction gives only an initial (minimum) value. The hydraulic conductivity of the compacted clay layer or of the geosynthetic clay liner may increase substantially, if there is no long-lasting protection against desiccation (by a thick soil cover or by a geomembrane). This has to be taken into account in landfill cover design.

  1. Tubular bioreactor and its application; Tubular bioreactor to sono tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Endo, I.; Nagamune, T. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Yuki, K. [Nikka Whisky Distilling Co. Ltd. Tokyo (Japan); Inaba, H. [Sumitomo Heavy Industries, Ltd., Tokyo (Japan)

    1994-09-05

    The loop type tubular bioreactor (TBR) was developed where biocatalysts are trapped in the reactor by membrane module. A UF membrane or MF membrane and crossflow filtration were adopted for the membrane module, and the reactor loop was composed of four membrane modules. The reactor was operated at 2-4 m/s in membrane surface velocity and 300-400 kPa in filtration pressure. As the result of the high-density culture of lactic acid bacteria and yeast, a biomass concentration was more than 10 times that in batch culture, suggesting the remarkable enhancement of a production efficiency. As the result of the continuous fermentation of cider, the fast fermentation more than 60 times that in conventional ones was obtained together with the same quality as conventional ones. Such a fast fermentation was probably achieved by yeast suspended in the fermenter of TBR, by yeast hardly affected physico-chemically as compared with immobilized reactors, and by small effect of mass transfer on reaction systems. 4 refs., 6 figs.

  2. Redox zones of a landfill leachate pollution plume (Vejen, Denmark)

    DEFF Research Database (Denmark)

    Lyngkilde, John; Christensen, Thomas Højlund

    1992-01-01

    Downgradient from an old municipal landfill allowing leachate, rich in dissolved organic carbon, to enter a shallow sandy aerobic aquifer, a sequence of redoxe zones is identified from groundwater chemical analysis. Below the landfill, methanogenic conditions prevail, followed by sulfidogenic...... the fate of reactive pollutants leached from the landfill....

  3. Quantifying landfill biogas production potential in the U.S.

    Science.gov (United States)

    This study presents an overview of the biogas (biomethane) availability in U.S. landfills, calculated from EPA estimates of landfill capacities. This survey concludes that the volume of landfill-derived methane in the U.S. is 466 billion cubic feet per year, of which 66 percent is collected and onl...

  4. Denitrifying bioreactor clogging potential during wastewater treatment.

    Science.gov (United States)

    Christianson, Laura E; Lepine, Christine; Sharrer, Kata L; Summerfelt, Steven T

    2016-11-15

    Chemoheterotrophic denitrification technologies using woodchips as a solid carbon source (i.e., woodchip bioreactors) have been widely trialed for treatment of diffuse-source agricultural nitrogen pollution. There is growing interest in the use of this simple, relatively low-cost biological wastewater treatment option in waters with relatively higher total suspended solids (TSS) and chemical oxygen demand (COD) such as aquaculture wastewater. This work: (1) evaluated hydraulic retention time (HRT) impacts on COD/TSS removal, and (2) assessed the potential for woodchip clogging under this wastewater chemistry. Four pilot-scale woodchip denitrification bioreactors operated for 267 d showed excellent TSS removal (>90%) which occurred primarily near the inlet, and that COD removal was maximized at lower HRTs (e.g., 56% removal efficiency and 25 g of COD removed per m(3) of bioreactor per d at a 24 h HRT). However, influent wastewater took progressively longer to move into the woodchips likely due to a combination of (1) woodchip settling, (2) clogging due to removed wastewater solids and/or accumulated bacterial growth, and (3) the pulsed flow system pushing the chips away from the inlet. The bioreactor that received the highest loading rate experienced the most altered hydraulics. Statistically significant increases in woodchip P content over time in woodchip bags placed near the bioreactor outlets (0.03 vs 0.10%P2O5) and along the bioreactor floor (0.04 vs. 0.12%P2O5) confirmed wastewater solids were being removed and may pose a concern for subsequent nutrient mineralization and release. Nevertheless, the excellent nitrate-nitrogen and TSS removal along with notable COD removal indicated woodchip bioreactors are a viable water treatment technology for these types of wastewaters given they are used downstream of a filtration device. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Optimizing of Culture Condition in Horizontal Rotating Bioreactor

    Institute of Scientific and Technical Information of China (English)

    Yan-Fang ZHANG; Huai-Qing CHEN; Hua HUANG

    2005-01-01

    @@ 1 Introduction Bioreactor is the most important equipment in tissue engineering. It can mimic the micro-environment of cell growth in vitro. At present, horizontal rotating bioreactor is the most advanced equipment for cell culture in the world.

  6. 40 CFR 63.1955 - What requirements must I meet?

    Science.gov (United States)

    2010-07-01

    ... operate a bioreactor that is located at a MSW landfill that is not permanently closed and has a design... the collection and control system into each new cell or area of the bioreactor prior to...

  7. Nitrogen removal and spatial distribution of denitrifier and anammox communities in a bioreactor for mine drainage treatment.

    Science.gov (United States)

    Herbert, Roger B; Winbjörk, Harry; Hellman, Maria; Hallin, Sara

    2014-12-01

    design favored preferential flow along these flowpaths, away from the sides of the bioreactor. An improved bioreactor design should consider the role of preferential flowpaths and the heterogeneous distribution of the genetic potential for denitrification, nitrous oxide reduction and anammox on bioreactor function.

  8. US EPA record of decision review for landfills: Sanitary landfill (740-G), Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    1993-06-01

    This report presents the results of a review of the US Environmental Protection Agency (EPA) Record of Decision System (RODS) database search conducted to identify Superfund landfill sites where a Record of Decision (ROD) has been prepared by EPA, the States or the US Army Corps of Engineers describing the selected remedy at the site. ROD abstracts from the database were reviewed to identify site information including site type, contaminants of concern, components of the selected remedy, and cleanup goals. Only RODs from landfill sites were evaluated so that the results of the analysis can be used to support the remedy selection process for the Sanitary Landfill at the Savannah River Site (SRS).

  9. A Multi-Paradigm Modeling Framework to Simulate Dynamic Reciprocity in a Bioreactor

    Science.gov (United States)

    Kaul, Himanshu; Cui, Zhanfeng; Ventikos, Yiannis

    2013-01-01

    Despite numerous technology advances, bioreactors are still mostly utilized as functional black-boxes where trial and error eventually leads to the desirable cellular outcome. Investigators have applied various computational approaches to understand the impact the internal dynamics of such devices has on overall cell growth, but such models cannot provide a comprehensive perspective regarding the system dynamics, due to limitations inherent to the underlying approaches. In this study, a novel multi-paradigm modeling platform capable of simulating the dynamic bidirectional relationship between cells and their microenvironment is presented. Designing the modeling platform entailed combining and coupling fully an agent-based modeling platform with a transport phenomena computational modeling framework. To demonstrate capability, the platform was used to study the impact of bioreactor parameters on the overall cell population behavior and vice versa. In order to achieve this, virtual bioreactors were constructed and seeded. The virtual cells, guided by a set of rules involving the simulated mass transport inside the bioreactor, as well as cell-related probabilistic parameters, were capable of displaying an array of behaviors such as proliferation, migration, chemotaxis and apoptosis. In this way the platform was shown to capture not only the impact of bioreactor transport processes on cellular behavior but also the influence that cellular activity wields on that very same local mass transport, thereby influencing overall cell growth. The platform was validated by simulating cellular chemotaxis in a virtual direct visualization chamber and comparing the simulation with its experimental analogue. The results presented in this paper are in agreement with published models of similar flavor. The modeling platform can be used as a concept selection tool to optimize bioreactor design specifications. PMID:23555740

  10. A multi-paradigm modeling framework to simulate dynamic reciprocity in a bioreactor.

    Directory of Open Access Journals (Sweden)

    Himanshu Kaul

    Full Text Available Despite numerous technology advances, bioreactors are still mostly utilized as functional black-boxes where trial and error eventually leads to the desirable cellular outcome. Investigators have applied various computational approaches to understand the impact the internal dynamics of such devices has on overall cell growth, but such models cannot provide a comprehensive perspective regarding the system dynamics, due to limitations inherent to the underlying approaches. In this study, a novel multi-paradigm modeling platform capable of simulating the dynamic bidirectional relationship between cells and their microenvironment is presented. Designing the modeling platform entailed combining and coupling fully an agent-based modeling platform with a transport phenomena computational modeling framework. To demonstrate capability, the platform was used to study the impact of bioreactor parameters on the overall cell population behavior and vice versa. In order to achieve this, virtual bioreactors were constructed and seeded. The virtual cells, guided by a set of rules involving the simulated mass transport inside the bioreactor, as well as cell-related probabilistic parameters, were capable of displaying an array of behaviors such as proliferation, migration, chemotaxis and apoptosis. In this way the platform was shown to capture not only the impact of bioreactor transport processes on cellular behavior but also the influence that cellular activity wields on that very same local mass transport, thereby influencing overall cell growth. The platform was validated by simulating cellular chemotaxis in a virtual direct visualization chamber and comparing the simulation with its experimental analogue. The results presented in this paper are in agreement with published models of similar flavor. The modeling platform can be used as a concept selection tool to optimize bioreactor design specifications.

  11. Correlation between microbial community and granule conductivity in anaerobic bioreactors for brewery wastewater treatment

    DEFF Research Database (Denmark)

    Shrestha, Pravin; Malvankar, Nikhil S.; Werner, Jeffrey

    2014-01-01

    granules from an aerobic bioreactor designed for phosphate removal were not. There was a moderate correlation (r = 0.67) between the abundance of Geobacter species in the UASB granules and granule conductivity, suggesting that Geobacter contributed to granule conductivity. These results, coupled...

  12. Nitrogen Removal by a Nitritation-Anammox Bioreactor at Low Temperature

    NARCIS (Netherlands)

    Hu, Z.; Lotti, T.; De Kreuk, B.M.; Kleerebezem, R.; Van Loosdrecht, M.; Kruit, J.; Jetten, M.S.M.; Kartala, B.

    2013-01-01

    Currently, nitritation-anammox (anaerobic ammonium oxidation) bioreactors are designed to treat wastewaters with high ammonium concentrations at mesophilic temperatures (25 to 40°C). The implementation of this technology at ambient temperatures for nitrogen removal from municipal wastewater followin

  13. Empirical correlation of volumetric mass transfer coefficient for a rectangular internal-loop airlift bioreactor

    Science.gov (United States)

    An empirical correlation of volumetric mass transfer coefficient was developed for a pilot scale internal-loop rectangular airlift bioreactor that was designed for biotechnology. The empirical correlation combines classic turbulence theory, Kolmogorov’s isotropic turbulence theory with Higbie’s pen...

  14. Pseudomonas kuykendallii sp. nov.: A novel y-Proteobacteria isolated from a hexazinone degrading bioreactor

    Science.gov (United States)

    Three strains of Gram-negative bacteria designated strains H2T, H6, and H7 were isolated from bioreactors that degraded the herbicide hexazinone. Similar morphological characteristics, cellular fatty acid profiles and 16S rRNA gene sequences show that the isolates are members of the same species. ...

  15. Landfill stabilization focus area: Technology summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    Landfills within the DOE Complex as of 1990 are estimated to contain 3 million cubic meters of buried waste. The DOE facilities where the waste is predominantly located are at Hanford, the Savannah River Site (SRS), the Idaho National Engineering Laboratory (INEL), the Los Alamos National Laboratory (LANL), the Oak Ridge Reservation (ORR), the Nevada Test Site (NTS), and the Rocky Flats Plant (RFP). Landfills include buried waste, whether on pads or in trenches, sumps, ponds, pits, cribs, heaps and piles, auger holes, caissons, and sanitary landfills. Approximately half of all DOE buried waste was disposed of before 1970. Disposal regulations at that time permitted the commingling of various types of waste (i.e., transuranic, low-level radioactive, hazardous). As a result, much of the buried waste throughout the DOE Complex is presently believed to be contaminated with both hazardous and radioactive materials. DOE buried waste typically includes transuranic-contaminated radioactive waste (TRU), low-level radioactive waste (LLW), hazardous waste per 40 CFR 26 1, greater-than-class-C waste per CFR 61 55 (GTCC), mixed TRU waste, and mixed LLW. The mission of the Landfill Stabilization Focus Area is to develop, demonstrate, and deliver safer,more cost-effective and efficient technologies which satisfy DOE site needs for the remediation and management of landfills. The LSFA is structured into five technology areas to meet the landfill remediation and management needs across the DOE complex. These technology areas are: assessment, retrieval, treatment, containment, and stabilization. Technical tasks in each of these areas are reviewed.

  16. Electrocoagulation and decolorization of landfill leachate

    Science.gov (United States)

    Mussa, Zainab Haider; Othman, Mohamed Rozali; Abdullah, Md Pauzi

    2013-11-01

    In this study, several operating conditions such as electrode material, treatment time, applied voltage, Cl□ concentration and PH of solution were tested on treatability of landfill leachate by using electrocoagulation (EC) method. According to the results, EC method can be used efficiently for the treatment of landfill leachate by using proper operating conditions. The best removal rats were obtained when C (rod) electrode as anode, operating time is 120 min, voltage applied is 10 V, NaCl concentration is 5.85 g/L and the raw PH, for these conditions, 70% color removal was obtained.

  17. Long and short term pump testing for landfill gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, D.W.; Fleming, I.R. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Civil and Geological Engineering

    2009-07-01

    A study was conducted to evaluate vertical well designs drilled into existing landfills as part of a landfill gas collection retrofitting project. Well designs and construction techniques were compared in relation to pneumatic efficiency and the capacity of each well. The aim of the study was to devise a method of evaluating well efficiency and long-term performance. Short-term, single well step-drawdown tests were conducted. Long-term pumping from the entire well field was conducted using different flow rate control approaches. Flow rates were measured at several different system pressures. Data were then compared with drawdown flow rate data from the short-term tests. The study proved that the single well short-term tests accurately predicted the long-term performance of the well field. The study also demonstrated that there was no apparent relationship between well productivity and the length of the screened zone, the diameter of the well, or the diameter of the borehole. No relationship was observed between well performance and the capital costs of individual wells.

  18. Methane Gas Utilization Project from Landfill at Ellery (NY)

    Energy Technology Data Exchange (ETDEWEB)

    Pantelis K. Panteli

    2012-01-10

    Landfill Gas to Electric Energy Generation and Transmission at Chautauqua County Landfill, Town of Ellery, New York. The goal of this project was to create a practical method with which the energy, of the landfill gas produced by the decomposing waste at the Chautauqua County Landfill, could be utilized. This goal was accomplished with the construction of a landfill gas to electric energy plant (originally 6.4MW and now 9.6MW) and the construction of an inter-connection power-line, from the power-plant to the nearest (5.5 miles) power-grid point.

  19. Influence of landfill structures on stabilization of fully recycled leachate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The experiment was conducted to treat the leachate from two simulating columns by recycling to the columns themselves without being discharged into the enviroment. The columns were employed to simulate anaerobic and semi-aerobic landfills separately. The influence of landfill structure on stabilization of fully recycled leachate was studied. The results show that semi-aerobic landfill structure accelerates the stabilization of leachate recycled. The full recycle of leachate in semi-aerobic landfill is a very feasible and effective technology for leachate treatment with low cost and energy saving especially in arid and rare rainfall regions. Meanwhile, the environmental impact of landfill can be greatly minimized.

  20. Microbiological indication of municipal solid waste landfill non-stabilization

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qi-xing; SYLVESTER Runyuzi; YU Ji-yu; ZHANG Qian-ru

    2004-01-01

    Accidental collapse resulted from unstable factors is an important technological problem to be solved in sanitary landfill. Microbiological degradation of organic matters in landfilled solid waste are an important unstable factor. A landfill reactor was thus manufactured and installed to examine quantitative and population dynamics of microorganisms during degradation of landfilled solid waste. It was showed that unstable landfill can be reflected and indicated by microbiological features such as rapidly decreased growth amount of microorganisms, no detection of fungi and actinomyces, and changing the dominant population into methanogenic bacteria and Acinotobacter.