Science.gov

Sample records for landfill gas production

  1. Observations from using models to fit the gas production of varying volume test cells and landfills.

    PubMed

    Lamborn, Julia

    2012-12-01

    Landfill operators are looking for more accurate models to predict waste degradation and landfill gas production. The simple microbial growth and decay models, whilst being easy to use, have been shown to be inaccurate. Many of the newer and more complex (component) models are highly parameter hungry and many of the required parameters have not been collected or measured at full-scale landfills. This paper compares the results of using different models (LANDGEM, HBM, and two Monod models developed by the author) to fit the gas production of laboratory scale, field test cell and full-scale landfills and discusses some observations that can be made regarding the scalability of gas generation rates. The comparison of these results show that the fast degradation rate that occurs at laboratory scale is not replicated at field-test cell and full-scale landfills. At small scale, all the models predict a slower rate of gas generation than actually occurs. At field test cell and full-scale a number of models predict a faster gas generation than actually occurs. Areas for future work have been identified, which include investigations into the capture efficiency of gas extraction systems and into the parameter sensitivity and identification of the critical parameters for field-test cell and full-scale landfill predication.

  2. Easy landfill gas profits

    SciTech Connect

    Schleifer, R.

    1988-03-01

    Landfill and digester gases can be valuable fuels. Engine-driven energy recovery systems are a common sight today at landfills and wastewater treatment plants. Yet the complaint is still heard: ''Waste'' gases are tough on engines. That can be true when impurities and variability in landfill or digester gas are not controlled. But with today's fuel-system technology, control is not difficult. Typically, custom-engineered fuel systems for alternate-fuel engine applications can include filters, scrubbers, separators, calorimeters, or other devices needed to deliver an acceptable gas to the engine. It's important that this system is designed only after a thorough gas analysis.

  3. Landfill gas cleanup for fuel cells

    SciTech Connect

    1995-08-01

    EPRI is to test the feasibility of using a carbonate fuel cell to generate electricity from landfill gas. Landfills produce a substantial quantity of methane gas, a natural by-product of decaying organic wastes. Landfill gas, however, contains sulfur and halogen compounds, which are known contaminants to fuel cells and their fuel processing equipment. The objective of this project is to clean the landfill gas well enough to be used by the fuel cell without making the process prohibitively expensive. The cleanup system tested in this effort could also be adapted for use with other fuel cells (e.g., solid oxide, phosphoric acid) running on landfill gas.

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

    EPA Science Inventory

    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...

  5. Landfill Gas Effects on Evapotranspirative Landfill Covers

    NASA Astrophysics Data System (ADS)

    Plummer, M. A.; Mattson, E.; Ankeny, M.; Kelsey, J.

    2005-05-01

    The performance of an evapotranspirative landfill cover can be adversely affected by transport of landfill gases to the plant root zone. Healthy plant communities are critical to the success and effectiveness of these vegetated landfill covers. Poor vegetative cover can result in reduced transpiration, increased percolation, and increased erosion regardless of the thickness of the cover. Visual inspections of landfill covers indicate that vegetation-free areas are not uncommon at municipal waste landfills. Data from soil profiles beneath these areas suggest that anaerobic conditions in the plant-rooting zone are controlling plant distribution. On the same landfill, aerobic conditions exist at similar depths beneath well-vegetated areas. The movement of methane and carbon dioxide, generated by degradation of organic wastes, into the overlying soil cover displaces oxygen in the root zone. Monitoring data from landfills in semi-arid areas indicate that barometric pumping can result in hours of anaerobic conditions in the root zone. Microbial consumption of oxygen in the root zone reduces the amount of oxygen available for plant root respiration but consumption of oxygen and methane also produce water as a reaction byproduct. This biogenic water production can be on the order of centimeters of water per year which, while increasing water availability, also has a negative feedback on transport of landfill gases through the cover. Accounting for these processes can improve evapotranspirative landfill cover design at other sites.

  6. Landfill gas recovery: An analysis of results

    NASA Astrophysics Data System (ADS)

    Peterson, J. M.

    1982-02-01

    Aspects of landfill gas recovery including the range of gas recovery, production rates, corrosion, medium-Btu industrial applications, and conversion to electricity via an internal combustion engine were investigated. It is estimated that the landfill site studied is capable of producing more than 2.17 x 10 to the 13th power Btu's of gas per year for a period of over eight years.

  7. Demonstration of landfill gas enhancement techniques in landfill simulators

    NASA Astrophysics Data System (ADS)

    Walsh, J. J.; Vogt, W. G.

    1982-02-01

    Various techniques to enhance gas production in sanitary landfills were applied to landfill simulators. These techniques include (1) accelerated moisture addition, (2) leachate recycling, (3) buffer addition, (4) nutrient addition, and (5) combinations of the above. Results are compiled through on-going operation and monitoring of sixteen landfill simulators. These test cells contain about 380 kg of municipal solid waste. Quantities of buffer and nutrient materials were placed in selected cells at the time of loading. Water is added to all test cells on a monthly basis; leachate is withdrawn from all cells (and recycled on selected cells) also on a monthly basis. Daily monitoring of gas volumes and refuse temperatures is performed. Gas and leachate samples are collected and analyzed on a monthly basis. Leachate and gas quality and quantity reslts are presented for the first 18 months of operation.

  8. Landfill gas management in Canada

    SciTech Connect

    David, A.

    1997-12-31

    Landfill gas produced from solid waste landfills is one of the most significant sources of anthropogenic methane in Canada. Methane, a potent greenhouse gas, is 24.5 times more powerful than carbon dioxide by weight in terms of global climate change. Landfill gas recovery plays an important role in Canada`s commitment to stabilize greenhouse gas emissions at 1990 levels by the year 2000 under the United Nations Framework Convention on Climate Change. Landfill gas is a potentially harmful emission that can be converted into a reliable environmentally-sustainable energy source used to generate electricity, fuel industries and heat buildings. The recovery and utilization of landfill gas is a win-win situation which makes good sense from local, regional and global perspectives. It provides the benefits of (1) reducing the release of greenhouse gases that contribute to global warming; (2) limiting odors; (3) controlling damage to vegetation; (4) reducing risks from explosions, fires and asphyxiation; (5) converting a harmful emission into a reliable energy source; and (6) creating a potential source of revenue and profit. Canadian landfills generate about 1 million tons of methane every year; the equivalent energy of 9 million barrels of oil (eight oil super tankers), or enough energy to meet the annual heating needs of more than half a million Canadian homes. Currently, twenty-seven facilities recover and combust roughly 25% of the methane generated by Canadian landfills producing about 3.2 PJ (10{sup 15} Joules) of energy including 80 MW of electricity and direct fuel for nearby facilities (e.g., cement plants, gypsum board manufacturers, recycling facilities, greenhouses). This paper reviews landfill gas characteristics; environmental, health and safety impacts; landfill gas management in Canada; the costs of landfill gas recovery and utilization systems; and on-going projects on landfill gas utilization and flaring.

  9. Integrated Cryogenic System for CO2 Separation and Lng Production from Landfill Gas

    NASA Astrophysics Data System (ADS)

    Chang, H. M.; Chung, M. J.; Park, S. B.

    2010-04-01

    An integrated cryogenic system to separate carbon dioxide (CO2) and produce LNG from landfill gas is investigated and designed. The main objective of this design is to eliminate the requirement of a standard CO2 removal process in the liquefaction system such distillation or (temperature or pressure) swing adsorption, and to directly separate carbon dioxide as frost at the liquefying channel of methane. Two identical sets of heat exchangers are installed in parallel and switched alternatively with a time period so that one is in separation-liquefaction mode while the other is in CO2 clean-up mode. A thermal regeneration scheme is presented for the purpose of saving energy and avoiding the stoppage of LNG production followed by the flow switching. The switching period is determined from results of a combined heat and mass transfer analysis on the CO2 freeze-out process.

  10. Evaluating leachate recirculation with cellulase addition to enhance waste biostabilisation and landfill gas production.

    PubMed

    Frank, R R; Davies, S; Wagland, S T; Villa, R; Trois, C; Coulon, F

    2016-09-01

    The effect of leachate recirculation with cellulase augmentation on municipal solid waste (MSW) biostabilisation and landfill gas production was investigated using batch bioreactors to determine the optimal conditions of moisture content, temperature and nutrients. Experimentation was thereafter scaled-up in 7L bioreactors. Three conditions were tested including (1) leachate recirculation only, (2) leachate recirculation with enzyme augmentation and (3) no leachate recirculation (control). Cumulative biogas production of the batch tests indicated that there was little difference between the leachate and control test conditions, producing on average 0.043m(3)biogaskg(-1) waste. However the addition of cellulase at 15×10(6)Utonne(-1) waste doubled the biogas production (0.074m(3)biogaskg(-1) waste). Similar trend was observed with the bioreactors. Cellulase addition also resulted in the highest COD reduction in both the waste and the leachate samples (47% and 42% COD reduction, respectively). In both cases, the quantity of biogas produced was closer to the lower value of theoretical and data-based biogas prediction indicators (0.05-0.4m(3)biogaskg(-1) waste). This was likely due to a high concentration of heavy metals present in the leachate, in particular Cr and Mn, which are known to be toxic to methanogens. The cost-benefit analysis (CBA) based on the settings of the study (cellulase concentration of 15×10(6)Utonne(-1) waste) showed that leachate bioaugmentation using cellulase is economically viable, with a net benefit of approximately €12.1million on a 5Mt mixed waste landfill. PMID:27397800

  11. Evaluating leachate recirculation with cellulase addition to enhance waste biostabilisation and landfill gas production.

    PubMed

    Frank, R R; Davies, S; Wagland, S T; Villa, R; Trois, C; Coulon, F

    2016-09-01

    The effect of leachate recirculation with cellulase augmentation on municipal solid waste (MSW) biostabilisation and landfill gas production was investigated using batch bioreactors to determine the optimal conditions of moisture content, temperature and nutrients. Experimentation was thereafter scaled-up in 7L bioreactors. Three conditions were tested including (1) leachate recirculation only, (2) leachate recirculation with enzyme augmentation and (3) no leachate recirculation (control). Cumulative biogas production of the batch tests indicated that there was little difference between the leachate and control test conditions, producing on average 0.043m(3)biogaskg(-1) waste. However the addition of cellulase at 15×10(6)Utonne(-1) waste doubled the biogas production (0.074m(3)biogaskg(-1) waste). Similar trend was observed with the bioreactors. Cellulase addition also resulted in the highest COD reduction in both the waste and the leachate samples (47% and 42% COD reduction, respectively). In both cases, the quantity of biogas produced was closer to the lower value of theoretical and data-based biogas prediction indicators (0.05-0.4m(3)biogaskg(-1) waste). This was likely due to a high concentration of heavy metals present in the leachate, in particular Cr and Mn, which are known to be toxic to methanogens. The cost-benefit analysis (CBA) based on the settings of the study (cellulase concentration of 15×10(6)Utonne(-1) waste) showed that leachate bioaugmentation using cellulase is economically viable, with a net benefit of approximately €12.1million on a 5Mt mixed waste landfill.

  12. Landfill gas project. Final report

    SciTech Connect

    1983-01-01

    The methane gas recovered from the landfill is used for space heating and water heating for the Florence-Lauderdale Humane Shelter 600 feet from the well head. The project to date and future development are described briefly. (MHR)

  13. Sour landfill gas problem solved

    SciTech Connect

    Nagl, G.; Cantrall, R.

    1996-05-01

    In Broward County, Fla., near Pompano Beach, Waste Management of North America (WMNA, a subsidiary of WMX Technologies, Oak Brook, IL) operates the Central Sanitary Landfill and Recycling Center, which includes the country`s largest landfill gas-to-energy plant. The landfill consists of three collection sites: one site is closed, one is currently receiving garbage, and one will open in the future. Approximately 9 million standard cubic feet (scf) per day of landfill gas is collected from approximately 300 wells spread over the 250-acre landfill. With a dramatic increase of sulfur-containing waste coming to a South Florida landfill following Hurricane Andrew, odors related to hydrogen sulfide became a serious problem. However, in a matter of weeks, an innovative desulfurization unit helped calm the landfill operator`s fears. These very high H{sub 2}S concentrations caused severe odor problems in the surrounding residential area, corrosion problems in the compressors, and sulfur dioxide (SO{sub 2}) emission problems in the exhaust gas from the turbine generators.

  14. Landfill gas energy recovery: Turning a liability into an asset

    SciTech Connect

    Nichols, M.

    1996-08-01

    Until the past decade, landfill gas (LFG) was viewed as a nuisance at best and a hazard at worst. Today, municipalities and private-sector solid waste management companies are findings ways to put landfill gas to productive use. Landfill gas energy recovery eliminates detrimental air emissions; prevents landfill methane from contributing to global climate change; stops methane from migrating off-site and becoming a safety hazard or odor problem; and provides local utilities, industry, and consumers with a competitive, local source of power. In other words, LFG-to-energy facilities provide a unique form of recycling--solid waste is hauled to the landfill as refuse and returned to the consumer in the form of energy. US EPA`s Landfill Methane Outreach Program (LMOP) and new EPA regulations for control of landfill gas emissions work together to encourage greater use of LFT at many facilities across the US.

  15. Mathematical modelling of landfill gas migration in MSW sanitary landfills.

    PubMed

    Martín, S; Marañón, E; Sastre, H

    2001-10-01

    The laws that govern the displacement of landfill gas in a sanitary landfill are analysed. Subsequently, a 2-D finite difference flow model of a fluid in a steady state in a porous medium with infinite sources of landfill gas is proposed. The fact that landfill gas is continuously generated throughout the entire mass of the landfill differentiates this model from others extensively described in the literature and used in a variety of different applications, such as oil recovery, groundwater flow, etc. Preliminary results are then presented of the application of the model. Finally, the results obtained employing data from the literature and experimental assays carried out at the La Zoreda sanitary landfill (Asturias, Spain) are discussed and future lines of research are proposed.

  16. An energy perspective on landfill gas

    SciTech Connect

    Hutchinson, P.J. )

    1993-01-01

    Globally, one billion metric tons of organic waste in the form of municipal solid waste are placed into solid-waste containment facilities every year. Complete biodegradation of this waste can generate approximately 2.8x10[sup 11] m[sup 3] (9.9 trillion cubic feet (Tcf) or 1.98x10[sup 8] metric tons) of biogas. Biogas consists of approximately equal proportions of methane and carbon dioxide; thus a year's worth of waste can potentially generate 1.4x10[sup 11] m[sup 3] (5 Tcf or 9.9x10[sup 7] metric tons) of methane. If we assume that landfill-biogas generation began only 20 years ago and has proceeded at a steady rate, then we can estimate that it can contribute 5x10[sup 10] m[sup 3] (1.8 Tcf or 36x10[sup 6] metric tons) of methane to the global atmospheric budget every year. Landfill gas is difficult to recover and use. Exploitation of biogas includes use as a raw product for heat energy, dehydration to produce electric generator fuel, refinement for commercial transportation, and use as a chemical feedstock. Controlled-reactor landfills, called [open quotes]biofills,[close quotes] are designed for optimum methane generation to ensure a steady and consistent rate of gas generation. Biofill mechanisms used to improve gas production include physical and chemical modifications to the modern landfill design. These methods can reduce the gas-generation time from 80 years to 5 years, can reduce the waste mass, and can reduce negative effects on the environment. 134 refs., 4 figs., 4 tabs.

  17. EPA`s landfill methane outreach program: Helping facilities save money and protect the environment by using landfill gas

    SciTech Connect

    Walsh, J.

    1997-06-01

    Until the past decade, landfill gas (LFG) was viewed as a nuisance at best and a hazard at worst. Today, many landfill owners and private-sector solid waste management companies are finding ways to put landfill gas to productive use. Landfill gas energy recovery eliminates detrimental air emissions; prevents landfill methane from contributing to global climate change; stops methane from migrating off-site and becoming a safety hazard or odor problem; and provides local utilities, industry, and consumers with a competitive, local source of power. In other words, LFG-to-energy facilities provide a unique form of recycling - solid waste is hauled to the landfill as refuse and returned to the consumer in the form of energy. US EPA`s Landfill Methane Outreach Program (LMOP) works to encourage greater use of LFG at facilities across the US.

  18. Alachua county southwest landfill gas production as a function of time. Master's thesis

    SciTech Connect

    Manley, G.R.

    1992-05-01

    Refuse disposal is an issue that must be addressed by virtually every community in the country. In the last twenty years, the demand for disposal techniques that minimize impact on the environment has increased. In addition, there has been a heightened interest in energy recovery from wastes as a method to reduce both the cost of waste disposal and national dependence on foreign energy supplies. The most common method of solid waste disposal in the United States is the utilization of sanitary landfills. Landfilling remains an economically viable method of solid waste disposal. Alternative means of disposal have often proven to be less effective in terms of both cost and in meeting solid waste disposal demands.

  19. LANDFILL GAS PRETREATMENT FOR FUEL CELL APPLICATIONS

    EPA Science Inventory

    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 ...

  20. How landfill gas causes RCRA compliance problems

    SciTech Connect

    Kerfoot, H.B.

    1996-06-01

    The Resource Conservation and Recovery Act (RCRA) requires landfill operators to monitor groundwater at their facilities. This regulatory requirement is designed to prevent contamination that can result as rainfall drains through refuse, causing pollutants to leach into the groundwater. Several parameters commonly associated with leachate are monitored under RCRA as indicator parameters, or parameters that represent readily detected indicators of contamination. These parameters include volatile organic compounds (VOCs) and alkalinity. Because of its potentially high concentration of VOCs and non-volatile contaminants, landfill leachate represents the greatest threat to groundwater from solid waste facilities. However, other sources can elevate indicator parameters as well. Increasingly lower detection limits can be achieved for VOCs in groundwater, enabling detection of VOCs and carbon dioxide (CO{sub 2}) from landfill gas. In addition, CO{sub 2} from landfill gas can increase groundwater alkalinity. Releases of VOCs in landfill gas can be eliminated by minimizing the gas pressure within the landfill, either by installing a gas-collection system or upgrading an existing gas-collection system by adding wells or altering gas flow in portions of the system.

  1. Operating a fuel cell using landfill gas

    SciTech Connect

    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.

  2. Landfill gas boosted to pipeline quality

    SciTech Connect

    Not Available

    1984-03-01

    The world's largest landfill recovery facility, located on Staten Island, went on stream in 1982 and is expected to produce 1.3 billion CF/yr of pipeline gas. Containing 45% carbon dioxide, the gas is compressed and cooled in stages to meet the requirements of the Selexol purification plant. Two 1120-kW (1500-hp) Copper Bessemer GMVS-8C integral gas engine-compressors, fueled by the landfill gas, provide the compression needed from the wells to the final solvent-contact stage.

  3. Emergency landfill gas control at the Milwaukee County Landfill

    SciTech Connect

    Michels, M.S.; Boone, D.A.

    1996-11-01

    In October 1994, up to 55 percent methane concentrations by volume were found below 76th Street in Franklin, Wisconsin. Numerous utilities exist below 76th Street which service homes located only 100 feet east. The Milwaukee County Landfill, located immediately west of 76th Street, was the source of methane gas. With winter weather conditions approaching, Milwaukee County was concerned that landfill gas (LFG) could migrate along utilities or in sandy soil and enter basements of adjacent homes. The County declared an emergency to immediately release funds and authorized a design/build contract to remedy the gas migration. CDM Engineers and Constructors, Inc. was selected for the project. The Milwaukee County Department of Public Works, Environmental Services Division led the project team. Numerous activities occurred simultaneously, including: (1) Public Relations, (2) Notification to Wisconsin DNR, (3) Design and Permitting, (4) Ordering the Flare, (5) Installing Methane Detectors in 29 Basements. Public relations included public forums with local residences, monthly newsletters, meetings with the ski hill operator, television interviews, local newspaper interviews, briefing the County Alderman and City of Franklin officials. Cooperation from Wisconsin DNR provided a 10-day turnaround for approval of the design. A perimeter active gas collection and flare system was employed to mitigate LFG. The system included eight gas extraction wells drilled to the base of the landfill and one horizontal trench (approximately 40 feet long). Extraction wells and trench were connected together with a buried 6-inch HDPE header pipe. Condensate is collected in a 550-gallon double-walled steel tank.

  4. Passive drainage and biofiltration of landfill gas: Australian field trial

    SciTech Connect

    Dever, S.A. . E-mail: stuart_dever@ghd.com.au; Swarbrick, G.E. . E-mail: g.swarbrick@unsw.edu.au; Stuetz, R.M. . E-mail: r.stuetz@unsw.edu.au

    2007-07-01

    In Australia a significant number of landfill waste disposal sites do not incorporate measures for the collection and treatment of landfill gas. This includes many old/former landfill sites, rural landfill sites, non-putrescible solid waste and inert waste landfill sites, where landfill gas generation is low and it is not commercially viable to extract and beneficially utilize the landfill gas. Previous research has demonstrated that biofiltration has the potential to degrade methane in landfill gas, however, the microbial processes can be affected by many local conditions and factors including moisture content, temperature, nutrient supply, including the availability of oxygen and methane, and the movement of gas (oxygen and methane) to/from the micro-organisms. A field scale trial is being undertaken at a landfill site in Sydney, Australia, to investigate passive drainage and biofiltration of landfill gas as a means of managing landfill gas emissions at low to moderate gas generation landfill sites. The design and construction of the trial is described and the experimental results will provide in-depth knowledge on the application of passive gas drainage and landfill gas biofiltration under Sydney (Australian) conditions, including the performance of recycled materials for the management of landfill gas emissions.

  5. Technical potential of electricity production from municipal solid waste disposed in the biggest cities in Brazil: landfill gas, biogas and thermal treatment.

    PubMed

    de Souza, Samuel Nm; Horttanainen, Mika; Antonelli, Jhonatas; Klaus, Otávia; Lindino, Cleber A; Nogueira, Carlos Ec

    2014-10-01

    This article presents an analysis of possibilities for electrical energy production by using municipal solid waste disposed in the biggest Brazilian cities. Currently, the municipal solid waste in Brazil is collected and disposed of at landfills, but there are also other technologies, which in addition to dealing with the garbage can also provide benefits in terms of energy provision. The following scenarios were studied in this work: electricity production from landfill gas (reference scenario); incineration of all municipal solid waste; anaerobic digestion of organic waste and incineration of refuse-derived fuel fractions after being separated in separation plants. According to this study, the biggest cities in Brazil generate about 18.9 million tonnes of municipal solid waste per year (2011), of which 51.5% is biogenic matter. The overall domestic consumption of electricity is 480,120 GWh y(-1) in Brazil and the municipal solid waste incineration in the 16 largest cities in the country could replace 1.8% of it using incinerators. The city of São Paulo could produce 637 GWh y(-1) with landfill gas, 2368 GWh y(-1) with incineration of municipal solid waste and 1177 GWh y(-1) with incineration of refuse-derived fuel. The latter two scenarios could replace 27% and 13.5% of the residential electrical energy consumption in the city. This shows that thermal treatment might be a viable option of waste-to-energy in Brazil.

  6. Technical potential of electricity production from municipal solid waste disposed in the biggest cities in Brazil: landfill gas, biogas and thermal treatment.

    PubMed

    de Souza, Samuel Nm; Horttanainen, Mika; Antonelli, Jhonatas; Klaus, Otávia; Lindino, Cleber A; Nogueira, Carlos Ec

    2014-10-01

    This article presents an analysis of possibilities for electrical energy production by using municipal solid waste disposed in the biggest Brazilian cities. Currently, the municipal solid waste in Brazil is collected and disposed of at landfills, but there are also other technologies, which in addition to dealing with the garbage can also provide benefits in terms of energy provision. The following scenarios were studied in this work: electricity production from landfill gas (reference scenario); incineration of all municipal solid waste; anaerobic digestion of organic waste and incineration of refuse-derived fuel fractions after being separated in separation plants. According to this study, the biggest cities in Brazil generate about 18.9 million tonnes of municipal solid waste per year (2011), of which 51.5% is biogenic matter. The overall domestic consumption of electricity is 480,120 GWh y(-1) in Brazil and the municipal solid waste incineration in the 16 largest cities in the country could replace 1.8% of it using incinerators. The city of São Paulo could produce 637 GWh y(-1) with landfill gas, 2368 GWh y(-1) with incineration of municipal solid waste and 1177 GWh y(-1) with incineration of refuse-derived fuel. The latter two scenarios could replace 27% and 13.5% of the residential electrical energy consumption in the city. This shows that thermal treatment might be a viable option of waste-to-energy in Brazil. PMID:25323146

  7. Economic and environmental benefits of landfill gas utilisation in Oman.

    PubMed

    Abushammala, Mohammed Fm; Qazi, Wajeeha A; Azam, Mohammed-Hasham; Mehmood, Umais A; Al-Mufragi, Ghithaa A; Alrawahi, Noor-Alhuda

    2016-08-01

    Municipal solid waste disposed in landfill sites decomposes under anaerobic conditions and produces so-called landfill-gas, which contains 30%-40% of carbon dioxide (CO2) and 50%-60% of methane (CH4). Methane has the potential of causing global warming 25 times more than CO2 Therefore, migration of landfill-gas from landfills to the surrounding environment can potentially affect human life and environment. Thus, this research aims to determine municipal solid waste generation in Oman over the years 1971-2030, to quantify annual CH4 emissions inventory that resulted from this waste over the same period of time, and to determine the economic and environmental benefits of capturing the CH4 gas for energy production. It is found that cumulative municipal solid waste landfilled in Oman reaches 3089 Giga gram (Gg) in the year 2030, of which approximately 85 Gg of CH4 emissions are produced in the year 2030. The study also found that capturing CH4 emissions between the years 2016 and 2030 could attract revenues of up to US$333 million and US$291 million from the carbon reduction and electricity generation, simultaneously. It is concluded that CH4 emissions from solid waste in Oman increases enormously with time, and capture of this gas for energy production could provide a sustainable waste management solution in Oman.

  8. Decomposition of forest products buried in landfills

    SciTech Connect

    Wang, Xiaoming; Padgett, Jennifer M.; Powell, John S.; Barlaz, Morton A.

    2013-11-15

    Highlights: • This study tracked chemical changes of wood and paper in landfills. • A decomposition index was developed to quantify carbohydrate biodegradation. • Newsprint biodegradation as measured here is greater than previous reports. • The field results correlate well with previous laboratory measurements. - Abstract: The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5 yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C + H) loss of up to 38%, while loss for the other wood types was 0–10% in most samples. The C + H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27 g OC g{sup −1} dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than

  9. Using landfill gas for energy: Projects that pay

    SciTech Connect

    1995-02-01

    Pending Environmental Protection Agency regulations will require 500 to 700 landfills to control gas emissions resulting from decomposing garbage. Conversion of landfill gas to energy not only meets regulations, but also creates energy and revenue for local governments.

  10. Keeping landfill gas systems in tune

    SciTech Connect

    Blackman, L.; Myers, L.; Bjerkin, L.; Freemon, P.

    1998-01-01

    The efficiency of LFG recovery systems is influenced by many complex and interrelated factors including atmospheric conditions and LFG dynamics. In order to balance the operation of a LFG system, the factors that influence the system, such as the effects of atmospheric conditions must be understood and taken into consideration. The dynamics include: typical, daily diurnal changes in barometric pressure and the temperature and density of the ambient air due to local meteorological conditions; major changes in barometric pressure and the temperature and density of ambient air due to transient high and low pressure systems related to weather conditions; dynamics of the biochemical activity within the landfill; and dynamics of the LFG flowing through the gas extraction system pipe lines. These factors dramatically influence LFG density, mass flow, quantity, and quality. They also influence the ability of a well designed gas collection system to effectively control gas migration and to provide a reasonably high gas product for energy recovery. Thus, an efficient LFG extraction system must attempt to compensate for these varying and uncontrollable conditions.

  11. Effect of leachate recirculation on landfill gas production and leachate quality: A controlled laboratory study

    SciTech Connect

    Bogner, J.; Spokas, K.

    1995-05-01

    This report summarizes the results of a laboratory study conducted during 1992-1994 at Argonne National Laboratory. The study examined biogas production and leachate chemistry in parallel anaerobic assays run under either leachate recycle or leachate drainage regimes over a period of 400 days. A standardized synthetic refuse (paper, grass, food) was used in an experimental design which evaluated two elevated moisture contents and two added soils. All assays were conducted in vitro in 125 mL serum bottles. Four recycle/drainage events were completed during the 400 days of this experiment. Sufficient replicates (10 or 20) for each trial were included in the experimental design to permit destructive sampling of assay solids after each recycle/drainage event. Changes in the chemistry of solid, liquid, and gaseous phases were evaluated during the decomposition process. Analyses included major gases (CH{sub 4}, CO{sub 2}, O{sub 2}, N{sub 2}), selected chemical constituents of leachate (Cl-C5 carboxylic acids, total organic carbon, Kjeldahl nitrogen, total phosphorus, iron, zinc, and chloride), leachate pH and conductivity, and selected solids analysis (gravimetric moisture content, volatile solids, total carbon, cellulose, hemicellulose, and lignin).

  12. Feasibility study for utilization of landfill gas at the Royalton Road Landfill, Broadview Heights, Ohio. Final report

    SciTech Connect

    1983-09-01

    The technical viability of landfill gas recovery has been previously demonstrated at numerous sites. However, the economics of a full scale utilization system are dependent on proper market conditions, appropriate technologies, landfill gas quantity and quality, and public/purchaser acceptance. The specific objectives of this feasibility study were to determine: The available markets which might purchase landfill gas or landfill gas derived energy products; An extraction system concept design and to perform an on-site pumping test program; The landfill gas utilization technologies most appropriate for the site; Any adverse environmental, health, safety, or socioeconomic impacts associated with the various proposed technologies; The optimum project economics, based on markets and processes examined. Findings and recommendations were presented which review the feasibility of a landfill gas utilization facility on the Royalton Road Landfill. The three identified utilization alternatives are indeed technically feasible. However, current market considerations indicate that installation of a full scale system is not economically advisable at this time. This final report encompasses work performed by SCS Engineers from late 1980 to the present. Monitoring data from several extraction and monitoring wells is presented, including pumping rates and gas quality and quantity analysis. The Market Analysis Data Form, local climatological data, and barometric pressure data are included in the appendix section. 33 figures, 25 tables.

  13. Wastewater disposal to landfill-sites: a synergistic solution for centralized management of olive mill wastewater and enhanced production of landfill gas.

    PubMed

    Diamantis, Vasileios; Erguder, Tuba H; Aivasidis, Alexandros; Verstraete, Willy; Voudrias, Evangelos

    2013-10-15

    The present paper focuses on a largely unexplored field of landfill-site valorization in combination with the construction and operation of a centralized olive mill wastewater (OMW) treatment facility. The latter consists of a wastewater storage lagoon, a compact anaerobic digester operated all year round and a landfill-based final disposal system. Key elements for process design, such as wastewater pre-treatment, application method and rate, and the potential effects on leachate quantity and quality, are discussed based on a comprehensive literature review. Furthermore, a case-study for eight (8) olive mill enterprises generating 8700 m(3) of wastewater per year, was conceptually designed in order to calculate the capital and operational costs of the facility (transportation, storage, treatment, final disposal). The proposed facility was found to be economically self-sufficient, as long as the transportation costs of the OMW were maintained at ≤4.0 €/m(3). Despite that EU Landfill Directive prohibits wastewater disposal to landfills, controlled application, based on appropriately designed pre-treatment system and specific loading rates, may provide improved landfill stabilization and a sustainable (environmentally and economically) solution for effluents generated by numerous small- and medium-size olive mill enterprises dispersed in the Mediterranean region.

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

    PubMed

    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

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

    PubMed

    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

  16. Soil gas investigations at the Sanitary Landfill

    SciTech Connect

    Wyatt, D.E.; Pirkle, R.J.; Masdea, D.J.

    1992-07-01

    A soil gas survey was performed at the 740-G Sanitary Landfill of Savannah River Plant during December, 1990. The survey monitored the presence and distribution of the C[sub 1]C[sub 4] hydrocarbons; the C[sub 5]-C[sub 10] normal paraffins; the aromatic hydrocarbons, BTXE; selected chlorinated hydrocarbons; and mercury. Significant levels of several of these contaminants were found associated with the burial site. In the northern area of the Landfill, methane concentrations ranged up to 63% of the soil gas and were consistently high on the western side of the access road. To the east of the access road in the northern and southern area high concentrations of methane were encountered but were not consistently high. Methane, the species found in highest concentration in the landfill, was generated in the landfill as the result of biological oxidation of cellulose and other organics to carbon dioxide followed by reduction of the carbon dioxide to methane. Distributions of other species are the result of burials in the landfill of solvents or other materials.

  17. Soil gas investigations at the Sanitary Landfill

    SciTech Connect

    Wyatt, D.E.; Pirkle, R.J.; Masdea, D.J.

    1992-07-01

    A soil gas survey was performed at the 740-G Sanitary Landfill of Savannah River Plant during December, 1990. The survey monitored the presence and distribution of the C{sub 1}C{sub 4} hydrocarbons; the C{sub 5}-C{sub 10} normal paraffins; the aromatic hydrocarbons, BTXE; selected chlorinated hydrocarbons; and mercury. Significant levels of several of these contaminants were found associated with the burial site. In the northern area of the Landfill, methane concentrations ranged up to 63% of the soil gas and were consistently high on the western side of the access road. To the east of the access road in the northern and southern area high concentrations of methane were encountered but were not consistently high. Methane, the species found in highest concentration in the landfill, was generated in the landfill as the result of biological oxidation of cellulose and other organics to carbon dioxide followed by reduction of the carbon dioxide to methane. Distributions of other species are the result of burials in the landfill of solvents or other materials.

  18. FUEL CELL ENERGY RECOVERY FROM LANDFILL GAS

    EPA Science Inventory

    International Fuel Cells Corporation is conducting a US Environmental Protection Agency (EPA) sponsored program to demonstrate energy recovery from landfill gas using a commercial phosphoric acid fuel cell power plant. The US EPA is interested in fuel cells for this application b...

  19. Evaluation of the age of landfill gas methane in landfill gas-natural gas mixtures using co-occurring constituents.

    PubMed

    Kerfoot, Henry B; Hagedorn, Benjamin; Verwiel, Mark

    2013-06-01

    At a municipal solid waste landfill in southern California (USA) overlying a natural gas reservoir, methane was detected at concentrations of up to 40% (by volume) in perimeter soil gas probes. Stable isotope and (14)C values of methane together with gas composition (major components and volatile organic compounds) data were evaluated to assess the relative contributions of landfill gas and natural gas to the measured methane concentrations. The data was further used to estimate the residence time of the landfill gas in the probes. Results showed that up to 37% of the measured methane was derived from landfill gas. In addition, the landfill gas in the probe samples has undergone extensive alteration due to dissolution of carbon dioxide in pore water. Data further indicates that the measured methane was released from the waste approximately 1.2 to 9.4 years ago, rather than representing evidence of an ongoing release.

  20. A decision support tool for landfill methane generation and gas collection.

    PubMed

    Emkes, Harriet; Coulon, Frédéric; Wagland, Stuart

    2015-09-01

    This study presents a decision support tool (DST) to enhance methane generation at individual landfill sites. To date there is no such tool available to provide landfill decision makers with clear and simplified information to evaluate biochemical processes within a landfill site, to assess performance of gas production and to identify potential remedies to any issues. The current lack in understanding stems from the complexity of the landfill waste degradation process. Two scoring sets for landfill gas production performance are calculated with the tool: (1) methane output score which measures the deviation of the actual methane output rate at each site which the prediction generated by the first order decay model LandGEM; and (2) landfill gas indicators' score, which measures the deviation of the landfill gas indicators from their ideal ranges for optimal methane generation conditions. Landfill gas indicators include moisture content, temperature, alkalinity, pH, BOD, COD, BOD/COD ratio, ammonia, chloride, iron and zinc. A total landfill gas indicator score is provided using multi-criteria analysis to calculate the sum of weighted scores for each indicator. The weights for each indicator are calculated using an analytical hierarchical process. The tool is tested against five real scenarios for landfill sites in UK with a range of good, average and poor landfill methane generation over a one year period (2012). An interpretation of the results is given for each scenario and recommendations are highlighted for methane output rate enhancement. Results demonstrate how the tool can help landfill managers and operators to enhance their understanding of methane generation at a site-specific level, track landfill methane generation over time, compare and rank sites, and identify problems areas within a landfill site. PMID:26168873

  1. A decision support tool for landfill methane generation and gas collection.

    PubMed

    Emkes, Harriet; Coulon, Frédéric; Wagland, Stuart

    2015-09-01

    This study presents a decision support tool (DST) to enhance methane generation at individual landfill sites. To date there is no such tool available to provide landfill decision makers with clear and simplified information to evaluate biochemical processes within a landfill site, to assess performance of gas production and to identify potential remedies to any issues. The current lack in understanding stems from the complexity of the landfill waste degradation process. Two scoring sets for landfill gas production performance are calculated with the tool: (1) methane output score which measures the deviation of the actual methane output rate at each site which the prediction generated by the first order decay model LandGEM; and (2) landfill gas indicators' score, which measures the deviation of the landfill gas indicators from their ideal ranges for optimal methane generation conditions. Landfill gas indicators include moisture content, temperature, alkalinity, pH, BOD, COD, BOD/COD ratio, ammonia, chloride, iron and zinc. A total landfill gas indicator score is provided using multi-criteria analysis to calculate the sum of weighted scores for each indicator. The weights for each indicator are calculated using an analytical hierarchical process. The tool is tested against five real scenarios for landfill sites in UK with a range of good, average and poor landfill methane generation over a one year period (2012). An interpretation of the results is given for each scenario and recommendations are highlighted for methane output rate enhancement. Results demonstrate how the tool can help landfill managers and operators to enhance their understanding of methane generation at a site-specific level, track landfill methane generation over time, compare and rank sites, and identify problems areas within a landfill site.

  2. FIRST ORDER KINETIC GAS GENERATION MODEL PARAMETERS FOR WET LANDFILLS

    EPA Science Inventory

    Landfill gas is produced as a result of a sequence of physical, chemical, and biological processes occurring within an anaerobic landfill. Landfill operators, energy recovery project owners, regulators, and energy users need to be able to project the volume of gas produced and re...

  3. Decomposition of forest products buried in landfills.

    PubMed

    Wang, Xiaoming; Padgett, Jennifer M; Powell, John S; Barlaz, Morton A

    2013-11-01

    The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C+H) loss of up to 38%, while loss for the other wood types was 0-10% in most samples. The C+H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27gOCg(-1) dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than previously reported.

  4. Decomposition of forest products buried in landfills.

    PubMed

    Wang, Xiaoming; Padgett, Jennifer M; Powell, John S; Barlaz, Morton A

    2013-11-01

    The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C+H) loss of up to 38%, while loss for the other wood types was 0-10% in most samples. The C+H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27gOCg(-1) dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than previously reported. PMID:23942265

  5. FIELD TEST MEASUREMENTS AT FIVE MUNICIPAL SOLID WASTE LANDFILLS WITH LANDFILL GAS CONTROL TECHNOLOGY--FINAL REPORT

    EPA Science Inventory

    Research was conducted to evaluate landfill gas emissions at five municipal solid waste landfills which have modern control technology for landfill gas emissions. Comprehensive testing was conducted on the raw landfill gas and the combustion outlet exhaust. The project had two ...

  6. Methane Gas Utilization Project from Landfill at Ellery (NY)

    SciTech Connect

    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.

  7. Modelling biogas production of solid waste: application of the BGP model to a synthetic landfill

    NASA Astrophysics Data System (ADS)

    Rodrigo-Ilarri, Javier; Segura-Sobrino, Francisco

    2013-04-01

    Production of biogas as a result of the decomposition of organic matter included on solid waste landfills is still an issue to be understood. Reports on this matter are rarely included on the engineering construction projects of solid waste landfills despite it can be an issue of critical importance while operating the landfill and after its closure. This paper presents an application of BGP (Bio-Gas-Production) model to a synthetic landfill. The evolution in time of the concentrations of the different chemical compounds of biogas is studied. Results obtained show the impact on the air quality of different management alternatives which are usually performed in real landfills.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Microbial mitigation of greenhouse gas emissions from landfill cover soils

    NASA Astrophysics Data System (ADS)

    Lee, Sung-Woo

    Landfills are one of the major sources of methane (CH4), a potent greenhouse gas with a global warming potential (GWP) ˜23 times higher than that of carbon dioxide (CO2). Although some effective strategies have been formulated to prevent methane emissions from large landfills, many landfills allow methane to be freely emitted to the atmosphere. In such situations, it is often proposed to stimulate methanotrophs, a group of bacteria that consume methane, in the cover soil to prevent fugitive methane emissions. Several factors, however, must be addressed to make such a biogenic removal mechanism effective. First, methanotrophic activity can be inhibited by nonmethane organic compounds (NMOCs) that are commonly found in landfill soil gas. Second, although methanotrophs can be easily stimulated with the addition of nitrogenous fertilizers, biogenic production of nitrous oxide with a GWP ˜296 times higher than that of carbon dioxide, is also stimulated. To consider these issues, two general areas of research were performed. First, a dimensionless number was developed based on Michaelis-Menten kinetics that describes the effects of the presence of multiple NMOCs on methanotrophic growth and survival. This model was validated via experimental measurements of methanotrophic growth in the presence of varying amounts of NMOCs. Second, the effects of nutrient amendments on methane oxidation and nitrous oxide production were examined by constructing soil microcosms using landfill cover soils. Here, it was shown that the addition of ammonium in the presence of phenylacetylene stimulated methane oxidation but inhibited nitrous oxide production. Furthermore, to understand the methanotrophic community structure and activity in response to these amendments, DNA microarray and transcript analyses were performed. The results indicated the predominance of Type II methanotrophs but that Type I methanotrophs responded more significantly to these amendments. Also, substantial activity

  10. Modelling the behaviour of mechanical biological treatment outputs in landfills using the GasSim model.

    PubMed

    Donovan, S M; Bateson, T; Gronow, J R; Voulvoulis, N

    2010-03-15

    The pretreatment of the biodegradable components of municipal solid waste (MSW) has been suggested as a method of reducing landfill gas emissions. Mechanical biological treatment (MBT) is the technology being developed to provide this reduction in biodegradability, either as an alternative to source segregated collection or for dealing with residual MSW which still contains high levels of biodegradable waste. The compost like outputs (CLOs) from MBT plants can be applied to land as a soil conditioner; treated to produce a solid recovered fuel (SRF) or landfilled. In this study the impact that landfilling of these CLOs will have on gaseous emissions is investigated. It is important that the gas production behaviour of landfilled waste is well understood, especially in European member states where the mitigation of gaseous emissions is a legal requirement. Results of an experiment carried out to characterise the biodegradable components of pretreated biowastes have been used with the GasSim model to predict the long term emissions behaviour of landfills accepting these wastes, in varying quantities. The landfill directive also enforces the mitigation of potential methane emissions from landfills, and the ability of landfill operators to capture gaseous emissions from low emitting landfills of the future is discussed, as well as new techniques that could be used for the mitigation of methane generation. PMID:20092874

  11. TEST RESULTS FOR FUEL-CELL OPERATION ON LANDFILL GAS

    EPA Science Inventory

    Test results from a demonstration of fuel-cell (FC) energy recovery and control of landfill gas emissions are presented. The project addressed two major issues: (i) the design, construction, and testing of a landfill-gas cleanup system; and (ii) a field test of a commercial phos...

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

    NASA Astrophysics Data System (ADS)

    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.

  13. Feasibility of landfill gas as a liquefied natural gas fuel source for refuse trucks.

    PubMed

    Zietsman, Josias; Bari, Muhammad Ehsanul; Rand, Aaron J; Gokhale, Bhushan; Lord, Dominique; Kumar, Sunil

    2008-05-01

    The purpose of this paper is to develop a methodology to evaluate the feasibility of using landfill gas (LFG) as a liquefied natural gas (LNG) fuel source for heavy-duty refuse trucks operating on landfills. Using LFG as a vehicle fuel can make the landfills more self-sustaining, reduce their dependence on fossil fuels, and reduce emissions and greenhouse gases. Acrion Technologies Inc. in association with Mack Trucks Inc. developed a technology to generate LNG from LFG using the CO2 WASH process. A successful application of this process was performed at the Eco Complex in Burlington County, PA. During this application two LNG refuse trucks were operated for 600 hr each using LNG produced from gases from the landfill. The methodology developed in this paper can evaluate the feasibility of three LFG options: doing nothing, electricity generation, and producing LNG to fuel refuse trucks. The methodology involved the modeling of several components: LFG generation, energy recovery processes, fleet operations, economic feasibility, and decision-making. The economic feasibility considers factors such as capital, maintenance, operational, and fuel costs, emissions and tax benefits, and the sale of products such as surplus LNG and food-grade carbon dioxide (CO2). Texas was used as a case study. The 96 landfills in Texas were prioritized and 17 landfills were identified that showed potential for converting LFG to LNG for use as a refuse truck fuel. The methodology was applied to a pilot landfill in El Paso, TX. The analysis showed that converting LFG to LNG to fuel refuse trucks proved to be the most feasible option and that the methodology can be applied for any landfill that considers this option.

  14. Feasibility of landfill gas as a liquefied natural gas fuel source for refuse trucks.

    PubMed

    Zietsman, Josias; Bari, Muhammad Ehsanul; Rand, Aaron J; Gokhale, Bhushan; Lord, Dominique; Kumar, Sunil

    2008-05-01

    The purpose of this paper is to develop a methodology to evaluate the feasibility of using landfill gas (LFG) as a liquefied natural gas (LNG) fuel source for heavy-duty refuse trucks operating on landfills. Using LFG as a vehicle fuel can make the landfills more self-sustaining, reduce their dependence on fossil fuels, and reduce emissions and greenhouse gases. Acrion Technologies Inc. in association with Mack Trucks Inc. developed a technology to generate LNG from LFG using the CO2 WASH process. A successful application of this process was performed at the Eco Complex in Burlington County, PA. During this application two LNG refuse trucks were operated for 600 hr each using LNG produced from gases from the landfill. The methodology developed in this paper can evaluate the feasibility of three LFG options: doing nothing, electricity generation, and producing LNG to fuel refuse trucks. The methodology involved the modeling of several components: LFG generation, energy recovery processes, fleet operations, economic feasibility, and decision-making. The economic feasibility considers factors such as capital, maintenance, operational, and fuel costs, emissions and tax benefits, and the sale of products such as surplus LNG and food-grade carbon dioxide (CO2). Texas was used as a case study. The 96 landfills in Texas were prioritized and 17 landfills were identified that showed potential for converting LFG to LNG for use as a refuse truck fuel. The methodology was applied to a pilot landfill in El Paso, TX. The analysis showed that converting LFG to LNG to fuel refuse trucks proved to be the most feasible option and that the methodology can be applied for any landfill that considers this option. PMID:18512437

  15. Investigation of Integrated Subsurface Processing of Landfill Gas and Carbon Sequestration, Johnson County, Kansas

    SciTech Connect

    K. David Newell; Timothy R. Carr

    2007-03-31

    The Johnson County Landfill in Shawnee, KS is operated by Deffenbaugh Industries and serves much of metropolitan Kansas City. Refuse, which is dumped in large plastic-underlined trash cells covering several acres, is covered over with shale shortly after burial. The landfill waste, once it fills the cell, is then drilled by Kansas City LFG, so that the gas generated by anaerobic decomposition of the refuse can be harvested. Production of raw landfill gas from the Johnson County landfill comes from 150 wells. Daily production is approximately 2.2 to 2.5 mmcf, of which approximately 50% is methane and 50% is carbon dioxide and NMVOCs (non-methane volatile organic compounds). Heating value is approximately 550 BTU/scf. A upgrading plant, utilizing an amine process, rejects the carbon dioxide and NMVOCs, and upgrades the gas to pipeline quality (i.e., nominally a heating value >950 BTU/scf). The gas is sold to a pipeline adjacent to the landfill. With coal-bearing strata underlying the landfill, and carbon dioxide a major effluent gas derived from the upgrading process, the Johnson County Landfill is potentially an ideal setting to study the feasibility of injecting the effluent gas in the coals for both enhanced coalbed methane recovery and carbon sequestration. To these ends, coals below the landfill were cored and then were analyzed for their thickness and sorbed gas content, which ranged up to 79 scf/ton. Assuming 1 1/2 square miles of land (960 acres) at the Johnson County Landfill can be utilized for coalbed and shale gas recovery, the total amount of in-place gas calculates to 946,200 mcf, or 946.2 mmcf, or 0.95 bcf (i.e., 985.6 mcf/acre X 960 acres). Assuming that carbon dioxide can be imbibed by the coals and shales on a 2:1 ratio compared to the gas that was originally present, then 1682 to 1720 days (4.6 to 4.7 years) of landfill carbon dioxide production can be sequestered by the coals and shales immediately under the landfill. Three coal--the Bevier

  16. Albany Interim Landfill gas extraction and mobile power system: Using landfill gas to produce electricity. Final report

    SciTech Connect

    1997-06-01

    The Albany Interim Landfill Gas Extraction and Mobile Power System project served three research objectives: (1) determination of the general efficiency and radius of influence of horizontally placed landfill gas extraction conduits; (2) determination of cost and effectiveness of a hydrogen sulfide gas scrubber utilizing Enviro-Scrub{trademark} liquid reagent; and (3) construction and evaluation of a dual-fuel (landfill gas/diesel) 100 kW mobile power station. The horizontal gas extraction system was very successful; overall, gas recovery was high and the practical radius of influence of individual extractors was about 50 feet. The hydrogen sulfide scrubber was effective and its use appears feasible at typical hydrogen sulfide concentrations and gas flows. The dual-fuel mobile power station performed dependably and was able to deliver smooth power output under varying load and landfill gas fuel conditions.

  17. Landfill Gas Conversion to LNG and LCO{sub 2}. Final Report

    SciTech Connect

    Brown, W.R.; Cook, W. J.; Siwajek, L.A.

    2000-10-20

    This report summarizes work on the development of a process to produce LNG (liquefied methane) for heavy vehicle use from landfill gas (LFG) using Acrion's CO{sub 2} wash process for contaminant removal and CO{sub 2} recovery. Work was done in the following areas: (1) production of natural gas pipeline methane for liquefaction at an existing LNG facility, (2) production of LNG from sewage digester gas, (3) the use of mixed refrigerants for process cooling in the production of LNG, liquid CO{sub 2} and pipeline methane, (4) cost estimates for an LNG production facility at the Arden Landfill in Washington PA.

  18. USERS MANUAL: LANDFILL GAS EMISSIONS MODEL - VERSION 2.0

    EPA Science Inventory

    The document is a user's guide for a computer model, Version 2.0 of the Landfill Gas Emissions Model (LandGEM), for estimating air pollution emissions from municipal solid waste (MSW) landfills. The model can be used to estimate emission rates for methane, carbon dioxide, nonmet...

  19. Fuel Flexibility: Landfill Gas Contaminant Mitigation for Power Generation

    SciTech Connect

    Storey, John Morse; Theiss, Timothy J; Kass, Michael D; FINNEY, Charles E A; Lewis, Samuel; Kaul, Brian C; Besmann, Theodore M; Thomas, John F; Rogers, Hiram; Sepaniak, Michael

    2014-04-01

    This research project focused on the mitigation of silica damage to engine-based renewable landfill gas energy systems. Characterization of the landfill gas siloxane contamination, combined with characterization of the silica deposits in engines, led to development of two new mitigation strategies. The first involved a novel method for removing the siloxanes and other heavy contaminants from the landfill gas prior to use by the engines. The second strategy sought to interrupt the formation of hard silica deposits in the engine itself, based on inspection of failed landfill gas engine parts. In addition to mitigation, the project had a third task to develop a robust sensor for siloxanes that could be used to control existing and/or future removal processes.

  20. Feasibility study: utilization of landfill gas for a vehicle fuel system, Rossman's landfill, Clackamas County, Oregon

    SciTech Connect

    1981-01-01

    In 1978, a landfill operator in Oregon became interested in the technical and economic feasibility of recovering the methane generated in the landfill for the refueling of vehicles. DOE awarded a grant for a site-specific feasibility study of this concept. This study investigated the expected methane yield and the development of a conceptual gas-gathering system; gas processing, compressing, and storage systems; and methane-fueled vehicle systems. Cost estimates were made for each area of study. The results of the study are presented. Reasoning that gasoline prices will continue to rise and that approximately 18,000 vehicles in the US have been converted to operate on methane, a project is proposed to use this landfill as a demonstration site to produce and process methane and to fuel a fleet (50 to 400) vehicles with the gas produced in order to obtain performance and economic data on the systems used from gas collection through vehicle operation. (LCL)

  1. Methane production in simulated hybrid bioreactor landfill.

    PubMed

    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).

  2. BUNCOMBE COUNTY WASTEWATER PRE-TREATMENT AND LANDFILL GAS TO ENERGY PROJECT

    SciTech Connect

    Jon Creighton

    2012-03-13

    The objective of this project was to construct a landfill gas-to-energy (LFGTE) facility that generates a renewable energy source utilizing landfill gas to power a 1.4MW generator, while at the same time reducing the amount of leachate hauled offsite for treatment. The project included an enhanced gas collection and control system, gas conditioning equipment, and a 1.4 MW generator set. The production of cleaner renewable energy will help offset the carbon footprint of other energy sources that are currently utilized.

  3. Ultrasound assisted biogas production from landfill leachate

    SciTech Connect

    Oz, Nilgün Ayman Yarimtepe, Canan Can

    2014-07-15

    Highlights: • Effect of low frequency ultrasound pretreatment on leachate was investigated. • Three different ultrasound energy inputs (200, 400 and 600 W/l) was applied. • Low-frequency ultrasound treatment increased soluble COD in landfill leachate. • Application of ultrasound to leachate increased biogas production about 40%. • Application of ultrasound to leachate increased total methane production rate about 20%. - Abstract: The aim of this study is to increase biogas production and methane yield from landfill leachate in anaerobic batch reactors by using low frequency ultrasound as a pretreatment step. In the first part of the study, optimum conditions for solubilization of organic matter in leachate samples were investigated using various sonication durations at an ultrasound frequency of 20 kHz. The level of organic matter solubilization during ultrasonic pretreatment experiments was determined by calculating the ratio of soluble chemical oxygen demand (sCOD) to total chemical oxygen demand (tCOD). The sCOD/tCOD ratio was increased from 47% in raw leachate to 63% after 45 min sonication at 600 W/l. Non-parametric Friedman’s test indicated that ultrasonic pretreatment has a significant effect on sCOD parameter for leachate (p < 0.05). In the second part of the study, anaerobic batch reactors were operated for both ultrasonically pretreated and untreated landfill leachate samples in order to assess the effect of sonication on biogas and methane production rate. In anaerobic batch reactor feed with ultrasonically pretreated leachate, 40% more biogas was obtained compared to the control reactor. For statistical analysis, Mann–Whitney U test was performed to compare biogas and methane production rates for raw and pretreated leachate samples and it has been found that ultrasonic pretreatment significantly enhanced biogas and methane production rates from leachate (p < 0.05) in anaerobic batch reactors. The overall results showed that low frequency

  4. Analysis of factors affecting methane-gas recovery from six landfills. Final report Jul 90-Jul 91

    SciTech Connect

    Campbell, D.; Epperson, D.; Davis, L.; Peer, R.; Gray, W.

    1991-09-01

    The report gives results of a pilot study of six U.S. landfills that have methane (CH4) gas recovery systems. (NOTE: The study was a first step in developing a field testing program to gather data to identify key variables that affect CH4 generation and to develop an empirical model of CH4 generation based on those variables. The field test program development, in turn, is part of EPA/AEERL's research program aimed at improving global landfill CH4 emissions estimates.) To evaluate the effects of climate on CH4 production and recovery, the six sites represented a variety of moisture and temperature patterns (i.e., hot and wet, cool and wet, hot and dry). Landfill gas was tested at each landfill to evaluate the quality of the gas recovery data available at each. The testing included assessing the adequacy of on-site instrumentation and scanning the landfill surfaces for organic vapors that would indicate emissions of CH4. In addition, information on waste composition and landfill characteristics was sought for each landfill. Except for flow measurements, the test procedures selected were well suited to the types of gas recovery installations encountered at the landfills visited. Based on comparisons between EPA Reference Method 3C and instrument analyses of the landfill gas compositions, all on-site analysis instruments appeared to be operating with reasonable accuracy.

  5. Effects of landfill gas on subtropical woody plants

    NASA Astrophysics Data System (ADS)

    Chan, G. Y. S.; Wong, M. H.; Whitton, B. A.

    1991-05-01

    An account is given of the influence of landfill gas on tree growth in the field at Gin Drinkers' Bay (GDB) landfill, Hong Kong, and in the laboratory. Ten species ( Acacia confusa, Albizzia lebbek, Aporusa chinensis, Bombax malabaricum, Castanopsis fissa, Liquidambar formosana, Litsea glutinosa, Machilus breviflora, Pinus elliottii, and Tristania conferta), belonging to eight families, were transplanted to two sites, one with a high concentration of landfill gas in the cover soil (high-gas site, HGS) and the other with a relatively low concentration of gas (low-gas site, LGS). Apart from the gaseous composition, the general soil properties were similar. A strong negative correlation between tree growth and landfill gas concentration was observed. A laboratory study using the simulated landfill gas to fumigate seedlings of the above species showed that the adventitious root growth of Aporusa chinensis, Bombax malabaricum, Machilus breviflora, and Tristania confera was stimulated by the gas, with shallow root systems being induced. Acacia confusa, Albizzia lebbek, and Litsea glutinosa were gas-tolerant, while root growth of Castanopsis fissa, Liquidambar formosana, and Pinus elliottii was inhibited. In most cases, shoot growth was not affected, exceptions being Bombax malabaricum, Liquidambar formosana, and Tristania conferta, where stunted growth and/or reduced foliation was observed. A very high CO2 concentration in cover soil limits the depth of the root system. Trees with a shallow root system become very susceptible to water stress. The effects of low O2 concentration in soil are less important than the effects of high CO2 concentration. Acacia confusa, Albizzia lebbek, and Tristania conferta are suited for growth on subtropical completed landfills mainly due to their gas tolerance and/or drought tolerance.

  6. TECHNICAL ASSESSMENT OF FUEL CELL OPERATION ON LANDFILL GAS AT THE GROTON, CT, LANDFILL

    EPA Science Inventory

    The paper summarizes the results from a seminal assessment conducted on a fuel cell technology which generates electrical power from waste landfill gas. This assessment/ demonstration was the second such project conducted by the EPA, the first being conducted at the Penrose Power...

  7. Treating landfill gas hydrogen sulphide with mineral wool waste (MWW) and rod mill waste (RMW).

    PubMed

    Bergersen, Ove; Haarstad, Ketil

    2014-01-01

    Hydrogen sulphide (H2S) gas is a major odorant at municipal landfills. The gas can be generated from different waste fractions, for example demolition waste containing gypsum based plaster board. The removal of H2S from landfill gas was investigated by filtering it through mineral wool waste products. The flow of gas varied from 0.3 l/min to 3.0 l/min. The gas was typical for landfill gas with a mean H2S concentration of ca. 4500 ppm. The results show that the sulphide gas can effectively be removed by mineral wool waste products. The ratios of the estimated potential for sulphide precipitation were 19:1 for rod mill waste (RMW) and mineral wool waste (MWW). A filter consisting of a mixture of MWW and RMW, with a vertical perforated gas tube through the center of filter material and with a downward gas flow, removed 98% of the sulfide gas over a period of 80 days. A downward gas flow was more efficient in contacting the filter materials. Mineral wool waste products are effective in removing hydrogen sulphide from landfill gas given an adequate contact time and water content in the filter material. Based on the estimated sulphide removal potential of mineral wool and rod mill waste of 14 g/kg and 261 g/kg, and assuming an average sulphide gas concentration of 4500 ppm, the removal capacity in the filter materials has been estimated to last between 11 and 308 days. At the studied location the experimental gas flow was 100 times less than the actual gas flow. We believe that the system described here can be upscaled in order to treat this gas flow.

  8. Greenhouse gas reduction by recovery and utilization of landfill methane and CO{sub 2} technical and market feasibility study, Boului Landfill, Bucharest, Romania. Final report, September 30, 1997--September 19, 1998

    SciTech Connect

    Cook, W.J.; Brown, W.R.; Siwajek, L.; Sanders, W.I.; Botgros, I.

    1998-09-01

    The project is a landfill gas to energy project rated at about 4 megawatts (electric) at startup, increasing to 8 megawatts over time. The project site is Boului Landfill, near Bucharest, Romania. The project improves regional air quality, reduces emission of greenhouse gases, controls and utilizes landfill methane, and supplies electric power to the local grid. The technical and economic feasibility of pre-treating Boului landfill gas with Acrion`s new landfill gas cleanup technology prior to combustion for power production us attractive. Acrion`s gas treatment provides several benefits to the currently structured electric generation project: (1) increase energy density of landfill gas from about 500 Btu/ft{sup 3} to about 750 Btu/ft{sup 3}; (2) remove contaminants from landfill gas to prolong engine life and reduce maintenance;; (3) recover carbon dioxide from landfill gas for Romanian markets; and (4) reduce emission of greenhouse gases methane and carbon dioxide. Greenhouse gas emissions reduction attributable to successful implementation of the landfill gas to electric project, with commercial liquid CO{sub 2} recovery, is estimated to be 53 million metric tons of CO{sub 2} equivalent of its 15 year life.

  9. Recovery Act: Brea California Combined Cycle Electric Generating Plant Fueled by Waste Landfill Gas

    SciTech Connect

    Galowitz, Stephen

    2012-12-31

    The primary objective of the Project was to maximize the productive use of the substantial quantities of waste landfill gas generated and collected at the Olinda Landfill near Brea, California. An extensive analysis was conducted and it was determined that utilization of the waste gas for power generation in a combustion turbine combined cycle facility was the highest and best use. The resulting Project reflected a cost effective balance of the following specific sub-objectives: • Meeting the environmental and regulatory requirements, particularly the compliance obligations imposed on the landfill to collect, process and destroy landfill gas • Utilizing proven and reliable technology and equipment • Maximizing electrical efficiency • Maximizing electric generating capacity, consistent with the anticipated quantities of landfill gas generated and collected at the Olinda Landfill • Maximizing equipment uptime • Minimizing water consumption • Minimizing post-combustion emissions • The Project produced and will produce a myriad of beneficial impacts. o The Project created 360 FTE construction and manufacturing jobs and 15 FTE permanent jobs associated with the operation and maintenance of the plant and equipment. o By combining state-of-the-art gas clean up systems with post combustion emissions control systems, the Project established new national standards for best available control technology (BACT). o The Project will annually produce 280,320 MWh’s of clean energy o By destroying the methane in the landfill gas, the Project will generate CO2 equivalent reductions of 164,938 tons annually. The completed facility produces 27.4 MWnet and operates 24 hours a day, seven days a week.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Recovery Act: Johnston Rhode Island Combined Cycle Electric Generating Plant Fueled by Waste Landfill Gas

    SciTech Connect

    Galowitz, Stephen

    2013-06-30

    The primary objective of the Project was to maximize the productive use of the substantial quantities of waste landfill gas generated and collected at the Central Landfill in Johnston, Rhode Island. An extensive analysis was conducted and it was determined that utilization of the waste gas for power generation in a combustion turbine combined cycle facility was the highest and best use. The resulting project reflected a cost effective balance of the following specific sub-objectives. 1) Meet environmental and regulatory requirements, particularly the compliance obligations imposed on the landfill to collect, process and destroy landfill gas. 2) Utilize proven and reliable technology and equipment. 3) Maximize electrical efficiency. 4) Maximize electric generating capacity, consistent with the anticipated quantities of landfill gas generated and collected at the Central Landfill. 5) Maximize equipment uptime. 6) Minimize water consumption. 7) Minimize post-combustion emissions. To achieve the Project Objective the project consisted of several components. 1) The landfill gas collection system was modified and upgraded. 2) A State-of-the Art gas clean up and compression facility was constructed. 3) A high pressure pipeline was constructed to convey cleaned landfill gas from the clean-up and compression facility to the power plant. 4) A combined cycle electric generating facility was constructed consisting of combustion turbine generator sets, heat recovery steam generators and a steam turbine. 5) The voltage of the electricity produced was increased at a newly constructed transformer/substation and the electricity was delivered to the local transmission system. The Project produced a myriad of beneficial impacts. 1) The Project created 453 FTE construction and manufacturing jobs and 25 FTE permanent jobs associated with the operation and maintenance of the plant and equipment. 2) By combining state-of-the-art gas clean up systems with post combustion emissions control

  12. Forest products decomposition in municipal solid waste landfills.

    PubMed

    Barlaz, Morton A

    2006-01-01

    Cellulose and hemicellulose are present in paper and wood products and are the dominant biodegradable polymers in municipal waste. While their conversion to methane in landfills is well documented, there is little information on the rate and extent of decomposition of individual waste components, particularly under field conditions. Such information is important for the landfill carbon balance as methane is a greenhouse gas that may be recovered and converted to a CO(2)-neutral source of energy, while non-degraded cellulose and hemicellulose are sequestered. This paper presents a critical review of research on the decomposition of cellulosic wastes in landfills and identifies additional work that is needed to quantify the ultimate extent of decomposition of individual waste components. Cellulose to lignin ratios as low as 0.01-0.02 have been measured for well decomposed refuse, with corresponding lignin concentrations of over 80% due to the depletion of cellulose and resulting enrichment of lignin. Only a few studies have even tried to address the decomposition of specific waste components at field-scale. Long-term controlled field experiments with supporting laboratory work will be required to measure the ultimate extent of decomposition of individual waste components. PMID:16406564

  13. Forest products decomposition in municipal solid waste landfills

    SciTech Connect

    Barlaz, Morton A. . E-mail: barlaz@eos.ncsu.edu

    2006-07-01

    Cellulose and hemicellulose are present in paper and wood products and are the dominant biodegradable polymers in municipal waste. While their conversion to methane in landfills is well documented, there is little information on the rate and extent of decomposition of individual waste components, particularly under field conditions. Such information is important for the landfill carbon balance as methane is a greenhouse gas that may be recovered and converted to a CO{sub 2}-neutral source of energy, while non-degraded cellulose and hemicellulose are sequestered. This paper presents a critical review of research on the decomposition of cellulosic wastes in landfills and identifies additional work that is needed to quantify the ultimate extent of decomposition of individual waste components. Cellulose to lignin ratios as low as 0.01-0.02 have been measured for well decomposed refuse, with corresponding lignin concentrations of over 80% due to the depletion of cellulose and resulting enrichment of lignin. Only a few studies have even tried to address the decomposition of specific waste components at field-scale. Long-term controlled field experiments with supporting laboratory work will be required to measure the ultimate extent of decomposition of individual waste components.

  14. Ultrasound assisted biogas production from landfill leachate.

    PubMed

    Oz, Nilgün Ayman; Yarimtepe, Canan Can

    2014-07-01

    The aim of this study is to increase biogas production and methane yield from landfill leachate in anaerobic batch reactors by using low frequency ultrasound as a pretreatment step. In the first part of the study, optimum conditions for solubilization of organic matter in leachate samples were investigated using various sonication durations at an ultrasound frequency of 20 kHz. The level of organic matter solubilization during ultrasonic pretreatment experiments was determined by calculating the ratio of soluble chemical oxygen demand (sCOD) to total chemical oxygen demand (tCOD). The sCOD/tCOD ratio was increased from 47% in raw leachate to 63% after 45 min sonication at 600 W/l. Non-parametric Friedman's test indicated that ultrasonic pretreatment has a significant effect on sCOD parameter for leachate (p<0.05). In the second part of the study, anaerobic batch reactors were operated for both ultrasonically pretreated and untreated landfill leachate samples in order to assess the effect of sonication on biogas and methane production rate. In anaerobic batch reactor feed with ultrasonically pretreated leachate, 40% more biogas was obtained compared to the control reactor. For statistical analysis, Mann-Whitney U test was performed to compare biogas and methane production rates for raw and pretreated leachate samples and it has been found that ultrasonic pretreatment significantly enhanced biogas and methane production rates from leachate (p<0.05) in anaerobic batch reactors. The overall results showed that low frequency ultrasound pretreatment can be potentially used for wastewater management especially with integration of anaerobic processes.

  15. 40 CFR Table Hh-3 to Subpart Hh of... - Landfill Gas Collection Efficiencies

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Landfill Gas Collection Efficiencies... (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills Pt. 98, Subpt. HH, Table HH-3 Table HH-3 to Subpart HH of Part 98—Landfill Gas Collection...

  16. 40 CFR Table Hh-3 to Subpart Hh of... - Landfill Gas Collection Efficiencies

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Landfill Gas Collection Efficiencies... (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills Pt. 98, Subpt. HH, Table HH-3 Table HH-3 to Subpart HH of Part 98—Landfill Gas Collection...

  17. 40 CFR Table Hh-3 to Subpart Hh of... - Landfill Gas Collection Efficiencies

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Landfill Gas Collection Efficiencies... (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills Pt. 98, Subpt. HH, Table HH-3 Table HH-3 to Subpart HH of Part 98—Landfill Gas Collection...

  18. 40 CFR Table Hh-3 to Subpart Hh of... - Landfill Gas Collection Efficiencies

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Landfill Gas Collection Efficiencies... (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Municipal Solid Waste Landfills Pt. 98, Subpt. HH, Table HH-3 Table HH-3 to Subpart HH of Part 98—Landfill Gas Collection...

  19. LIQUID NATURAL GAS (LNG): AN ALTERNATIVE FUEL FROM LANDFILL GAS (LFG) AND WASTEWATER DIGESTER GAS

    SciTech Connect

    VANDOR,D.

    1999-03-01

    This Research and Development Subcontract sought to find economic, technical and policy links between methane recovery at landfill and wastewater treatment sites in New York and Maryland, and ways to use that methane as an alternative fuel--compressed natural gas (CNG) or liquid natural gas (LNG) -- in centrally fueled Alternative Fueled Vehicles (AFVs).

  20. Partitioning Gas Tracer Technology for Measuring Water in Landfills

    NASA Astrophysics Data System (ADS)

    Briening, M. L.; Jakubowitch, A.; Imhoff, P. T.; Chiu, P. C.; Tittlebaum, M. E.

    2002-12-01

    Unstable landfills can result in significant environmental contamination and can become a risk to public health. To reduce this risk, water may be added to landfills to ensure that enough moisture exists for biodegradation of organic wastes. In this case risks associated with future breaks in the landfill cap are significantly reduced because organic material is degraded more rapidly. To modify moisture conditions and enhance biodegradation, leachate is typically collected from the bottom of the landfill and then recirculated near the top. It is difficult, though, to know how much leachate to add and where to add it to achieve uniform moisture conditions. This situation is exacerbated by the heterogeneous nature of landfill materials, which is known to cause short circuiting of infiltrating water, a process that has been virtually impossible to measure or model. Accurate methods for measuring the amount of water in landfills would be valuable aids for implementing leachate recirculation systems. Current methods for measuring water are inadequate, though, since they provide point measurements and are frequently affected by heterogeneity of the solid waste composition and solid waste compaction. The value of point measurements is significantly reduced in systems where water flows preferentially, such as in landfills. Here, spatially integrated measurements might be of greater value. In this research we are evaluating a promising technology, the partitioning gas tracer test, to measure the water saturation within landfills, the amount of free water in solid waste divided by the volume of the voids. The partitioning gas tracer test was recently developed by researchers working in the vadose zone. In this methodology two gas tracers are injected into a landfill. One tracer is non-reactive with landfill materials, while the second partitions into and out of free water trapped within the pore space of the solid waste. Chromatographic separation of the tracers occurs

  1. EMERGING TECHNOLOGIES FOR THE MANAGEMENT AND UTILIZATION OF LANDFILL GAS

    EPA Science Inventory

    The report gives information on emerging technologies that are considered to be commercially available (Tier 1), currently undergoing research and development (Tier 2), or considered as potentially applicable (Tier 3) for the management of landfill gas (LFG) emissions or for the ...

  2. FUEL CELL OPERATION ON LANDFILL GAS AT PENROSE POWER STATION

    EPA Science Inventory

    This demonstration test successfully demonstrated operation of a commercial phosphoric acid fuel cell (FC) on landfill gas (LG) at the Penrose Power Station in Sun Valley, CA. Demonstration output included operation up to 137 kW; 37.1% efficiency at 120 kW; exceptionally low sec...

  3. Forecasting the settlement of a bioreactor landfill based on gas pressure changes.

    PubMed

    Qiu, Gang; Li, Liang; Sun, Hongjun

    2013-10-01

    In order to study the influence of settlement under gas pressure in bioreactor landfill, the landfill is simplified as a one-way gas seepage field, combining Darcy's Law, the gas equation of state, and the principle of effective stress and fluid dynamics of porous media theory. First assume that the bioreactor landfill leachate is fully recharged on the basis of gas mass conservation, then according to the changes in gas pressure (inside the landfill and surrounding atmosphere) during the gas leakage time and settlement in the landfill, establish a numerical model of bioreactor landfill settlement under the action of the gas pressure, and use the finite difference method to solve it. Through a case study, the model's improved prediction of the settlement of bioreactor landfill is demonstrated.

  4. Forecasting the settlement of a bioreactor landfill based on gas pressure changes.

    PubMed

    Qiu, Gang; Li, Liang; Sun, Hongjun

    2013-10-01

    In order to study the influence of settlement under gas pressure in bioreactor landfill, the landfill is simplified as a one-way gas seepage field, combining Darcy's Law, the gas equation of state, and the principle of effective stress and fluid dynamics of porous media theory. First assume that the bioreactor landfill leachate is fully recharged on the basis of gas mass conservation, then according to the changes in gas pressure (inside the landfill and surrounding atmosphere) during the gas leakage time and settlement in the landfill, establish a numerical model of bioreactor landfill settlement under the action of the gas pressure, and use the finite difference method to solve it. Through a case study, the model's improved prediction of the settlement of bioreactor landfill is demonstrated. PMID:23771879

  5. U.S. EPA'S RESEARCH TO UPDATE GUIDANCE FOR QUANTIFYING LANDFILL GAS EMISSIONS

    EPA Science Inventory

    Landfill emissions, if left uncontrolled, contribute to air toxics, climate change, tropospheric ozone, and urban smog. EPA's Office of Research and Development is conducting research to help update EPA's landfill gas emission factors. The last update to EPA's landfill gas emiss...

  6. Temporal variability of soil gas composition in landfill covers.

    PubMed

    Gebert, Julia; Rachor, Ingke; Gröngröft, Alexander; Pfeiffer, Eva-Maria

    2011-05-01

    In order to assess the temporal variability of the conditions for the microbial oxidation of methane in landfill cover soils and their driving variables, gas composition at non-emissive and strongly emissive locations (hotspots) was monitored on a seasonal, daily and hourly time scale on an old, unlined landfill in northern Germany. Our study showed that the impact of the various environmental factors varied with the mode of gas transport and with the time scale considered. At non-emissive sites, governed by diffusive gas transport, soil gas composition was subject to a pronounced seasonal variation. A high extent of aeration, low methane concentrations and a high ratio of CO(2) to CH(4) were found across the entire depth of the soil cover during the warm and dry period, whereas in the cool and moist period aeration was less and landfill gas migrated further upward. Statistically, variation in soil gas composition was best explained by the variation in soil temperature. At locations dominated by advective gas transport and showing considerable emissions of methane, this pattern was far less pronounced with only little increase in the extent of aeration during drier periods. Here, the change of barometric pressure was found to impact soil gas composition. On a daily scale under constant conditions of temperature, gas transport at both types of locations was strongly impacted by the change in soil moisture. On an hourly scale, under constant conditions of temperature and moisture, gas migration was impacted most by the change in barometric pressure. It was shown that at diffusion-dominated sites complete methane oxidation was achieved even under adverse wintry conditions, whereas at hotspots, even under favorable dry and warm conditions, aerobic biological activity can be limited to the upper crust of the soil.

  7. Evaluation of a 2-MW carbonate fuel cell power plant fueled by landfill gas. Final report

    SciTech Connect

    Meade, D.B.; Selander, S.; Rastler, D.M.

    1991-11-01

    This project assessed the technical and economic feasibility of operating an atmospheric pressure 2 MW carbonate fuel cell power plant on landfill gas. A commercially available low pressure gas pre-treatment system was identified for this application. System simulation studies were performed to identify component bottle-necks which would limit power production, or preclude system operation. An economic assessment was conducted to assess the competitiveness of the fuel cell system. The analysis confirmed the technical feasibility of operating Energy Research Corporation`s 2MW fuel cell system on landfill gas. Resulting net electrical efficiency was 50% based on the fuel`s lower heating value. Plant capital cost increased by {approximately}$180/kw; this was primarily for gas cleanup. Bus bar power costs for market entry and commercial fuel cell plants were found to be competitive with power produced from baseload coal plants in Minnesota.

  8. Evaluation of a 2-MW carbonate fuel cell power plant fueled by landfill gas

    SciTech Connect

    Meade, D.B. ); Selander, S. ); Rastler, D.M. )

    1991-11-01

    This project assessed the technical and economic feasibility of operating an atmospheric pressure 2 MW carbonate fuel cell power plant on landfill gas. A commercially available low pressure gas pre-treatment system was identified for this application. System simulation studies were performed to identify component bottle-necks which would limit power production, or preclude system operation. An economic assessment was conducted to assess the competitiveness of the fuel cell system. The analysis confirmed the technical feasibility of operating Energy Research Corporation's 2MW fuel cell system on landfill gas. Resulting net electrical efficiency was 50% based on the fuel's lower heating value. Plant capital cost increased by {approximately}$180/kw; this was primarily for gas cleanup. Bus bar power costs for market entry and commercial fuel cell plants were found to be competitive with power produced from baseload coal plants in Minnesota.

  9. Siloxane removal from landfill and digester gas - a technology overview.

    PubMed

    Ajhar, M; Travesset, M; Yüce, S; Melin, T

    2010-05-01

    This paper reviews technologies for the removal of volatile methyl siloxanes (VMS) from biogas. More than 20 years after identifying silicon dioxide in gas engines running on landfill and sewage gas, three technologies are commercially available to remove siloxanes today: adsorption, absorption and deep chilling. Newer concepts based on technologies other than sorption or condensation have not yet gained access to commercial biogas purification. These emerging siloxane removal concepts include biotrickling filters, catalysts, membranes, and in the case of sewage gas, sludge stripping, peroxidation and filtration at point inlet source. This work introduces the main principles of commercial siloxane removal systems and reviews scientific progress in the field over the last decade.

  10. Remote Real-Time Monitoring of Subsurface Landfill Gas Migration

    PubMed Central

    Fay, Cormac; Doherty, Aiden R.; Beirne, Stephen; Collins, Fiachra; Foley, Colum; Healy, John; Kiernan, Breda M.; Lee, Hyowon; Maher, Damien; Orpen, Dylan; Phelan, Thomas; Qiu, Zhengwei; Zhang, Kirk; Gurrin, Cathal; Corcoran, Brian; O’Connor, Noel E.; Smeaton, Alan F.; Diamond, Dermot

    2011-01-01

    The cost of monitoring greenhouse gas emissions from landfill sites is of major concern for regulatory authorities. The current monitoring procedure is recognised as labour intensive, requiring agency inspectors to physically travel to perimeter borehole wells in rough terrain and manually measure gas concentration levels with expensive hand-held instrumentation. In this article we present a cost-effective and efficient system for remotely monitoring landfill subsurface migration of methane and carbon dioxide concentration levels. Based purely on an autonomous sensing architecture, the proposed sensing platform was capable of performing complex analytical measurements in situ and successfully communicating the data remotely to a cloud database. A web tool was developed to present the sensed data to relevant stakeholders. We report our experiences in deploying such an approach in the field over a period of approximately 16 months. PMID:22163975

  11. Remote real-time monitoring of subsurface landfill gas migration.

    PubMed

    Fay, Cormac; Doherty, Aiden R; Beirne, Stephen; Collins, Fiachra; Foley, Colum; Healy, John; Kiernan, Breda M; Lee, Hyowon; Maher, Damien; Orpen, Dylan; Phelan, Thomas; Qiu, Zhengwei; Zhang, Kirk; Gurrin, Cathal; Corcoran, Brian; O'Connor, Noel E; Smeaton, Alan F; Diamond, Dermot

    2011-01-01

    The cost of monitoring greenhouse gas emissions from landfill sites is of major concern for regulatory authorities. The current monitoring procedure is recognised as labour intensive, requiring agency inspectors to physically travel to perimeter borehole wells in rough terrain and manually measure gas concentration levels with expensive hand-held instrumentation. In this article we present a cost-effective and efficient system for remotely monitoring landfill subsurface migration of methane and carbon dioxide concentration levels. Based purely on an autonomous sensing architecture, the proposed sensing platform was capable of performing complex analytical measurements in situ and successfully communicating the data remotely to a cloud database. A web tool was developed to present the sensed data to relevant stakeholders. We report our experiences in deploying such an approach in the field over a period of approximately 16 months. PMID:22163975

  12. Numerical modeling of landfill gas and heat transport in the deformable MSW landfill body. Part 2. Verification and application of the model

    NASA Astrophysics Data System (ADS)

    Kutsyi, D. V.

    2015-07-01

    The article is devoted to studying the parameters of wells that are used as part of vertical landfill gas collection systems for degassing landfills. To this end, the thermophysical model developed in the first part of this work is considered. The model is constructed using the initial data obtained at real dump and landfill with subsequently comparing the calculation results with the data of experimental measurements. A method for determining the average hydrodynamic properties of wastes is proposed, using which the heterogeneity of wastes can be taken into account. The effect the operating and design parameters of the well have on its performance is investigated on the basis of these properties. It has been determined that increasing the suction pressure, drilling diameter, and perforation height allows the well production rate to be increased by around 10%. The effect the increase of the well production rate has on the landfill gas collection project's payback period is demonstrated taking typical dump and landfill as an example.

  13. Response of tomato plants to simulated landfill gas mixtures

    SciTech Connect

    Arthur, J.J.; Leone, I.A.; Flower, F.B.

    1985-01-01

    The roots of tomato plants were fumigated with simulated refuse-generated gas mixtures at levels of methane (CH/sub 4/), carbon dioxide (CO/sub 2/), and oxygen (O/sub 2/) previously measured in the atmospheres of landfill cover soils associated with poor growth or death of plants. A concentration of 18% CO/sub 2/ or greater, exceeded in almost 30% of thirty-two landfills examined throughout the US, caused reduced growth and visible symptoms on tomato after 1 wk, regardless of O/sub 2/ level. Doubling the CO/sub 2/ level to that encountered in a typical local site (Edgeboro Landfill) resulted in more severe symptom development and the subsequent death of plants. Methane, in concentrations of 20% and above, found in more than 25% of the landfills visited, while not observed to be toxic per se; was associated with drastic O/sub 2/ depletion in the soil atmosphere, which activity was believed to be the cause of the plant decline.

  14. Greenhouse gas emissions during MSW landfilling in China: influence of waste characteristics and LFG treatment measures.

    PubMed

    Yang, Na; Zhang, Hua; Shao, Li-Ming; Lü, Fan; He, Pin-Jing

    2013-11-15

    Reducing greenhouse gas (GHG) emissions from municipal solid waste (MSW) treatment can be highly cost-effective in terms of GHG mitigation. This study investigated GHG emissions during MSW landfilling in China under four existing scenarios and in terms of seven different categories: waste collection and transportation, landfill management, leachate treatment, fugitive CH4 (FM) emissions, substitution of electricity production, carbon sequestration and N2O and CO emissions. GHG emissions from simple sanitary landfilling technology where no landfill gas (LFG) extraction took place (Scenario 1) were higher (641-998 kg CO2-eq·t(-1)ww) than those from open dump (Scenario 0, 480-734 kg CO2-eq·t(-1)ww). This was due to the strictly anaerobic conditions in Scenario 1. LFG collection and treatment reduced GHG emissions to 448-684 kg CO2-eq·t(-1)ww in Scenario 2 (with LFG flare) and 214-277 kg CO2-eq·t(-1)ww in Scenario 3 (using LFG for electricity production). Amongst the seven categories, FM was the predominant contributor to GHG emissions. Global sensitivity analysis demonstrated that the parameters associated with waste characteristics (i.e. CH4 potential and carbon sequestered faction) and LFG management (i.e. LFG collection efficiency and CH4 oxidation efficiency) were of great importance. A further learning on the MSW in China indicated that water content and dry matter content of food waste were the basic factors affecting GHG emissions. Source separation of food waste, as well as increasing the incineration ratio of mixed collected MSW, could effectively mitigate the overall GHG emissions from landfilling in a specific city. To increase the LFG collection and CH4 oxidation efficiencies could considerably reduce GHG emissions on the landfill site level. While, the improvement in the LFG utilization measures had an insignificant impact as long as the LFG is recovered for energy generation.

  15. Landfill gas and its influence on global climate change. Book chapter

    SciTech Connect

    Thorneloe, S.A.

    1993-01-01

    The report describes the relative importance of landfills to global warming and identifies the major sources of uncertainty with current emission estimates. It also provides an overview of EPA's research program on global landfill methane, including developing more reliable estimates of global landfill methane emissions, characterizing the current state of technology for controlling and utilizing landfill methane, and demonstrating innovative technologies for mitigating and utilizing landfill methane. Landfills are considered a major source of methane, which is a potent greenhouse gas. Because this source is amenable to cost effective control measures, research designed to reduce the uncertainty associated with methane emissions estimates has been given high priority.

  16. Effect of enhanced leachate recirculated (ELR) landfill operation and gas extraction on greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Samir, Sonia

    The bioreactor/ enhanced leachate recirculated (ELR) landfill operation with the addition of moisture/ leachate to the landfill, accelerate the process of landfill waste decomposition; and increase the generation of LFG over a shorter period of time. Since emissions from the landfills are directly related to the gas generation, the increase in gas generation might also increase the emission from the landfill. On the contrary, the presence of gas extraction is suggested to mitigate the fugitive emissions from the landfills. Therefore, the motivation of the current study was to evaluate the effect of ELR operation as well as the gas extraction on the greenhouse gas emissions from the landfill. The current study was conducted in the City of Denton Landfill, Texas. Methane emission was investigated using a portable FID and static flux chamber technique from the landfill surface. Emission was measured from an ELR operated cell (cell 2) as well as a conventional cell (cell 0) in the City of Denton Landfill. Methane emission for cell 2 varied from 9544.3 ppm to 0 ppm while for cell 0, it varied from 0 ppm to 47 ppm. High spatial variations were observed during monitoring from both cells 0 and cell 2 which could be recognized as the variation of gas generation below the cover soil. The comparison between emissions from the slope and surface of the landfill showed that more methane emission occurred from the slopes than the top surface. In addition, the average landfill emission showed an increasing trend with increase in temperature and decreasing trend with increasing precipitation. The effect of ELR operation near the recirculation pipes showed a lag period between the recirculation and the maximum emission near the pipe. The emission near the pipe decreased after 1 day of recirculation and after the initial decrease, the emission started to increase and continued to increase up to 7 days after the recirculation. However, approximately after 10 days of recirculation, the

  17. Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils

    SciTech Connect

    Jeremy Semrau; Sung-Woo Lee; Jeongdae Im; Sukhwan Yoon; Michael Barcelona

    2010-09-30

    The overall objective of this project, 'Strategies to Optimize Microbially-Mediated Mitigation of Greenhouse Gas Emissions from Landfill Cover Soils' was to develop effective, efficient, and economic methodologies by which microbial production of nitrous oxide can be minimized while also maximizing microbial consumption of methane in landfill cover soils. A combination of laboratory and field site experiments found that the addition of nitrogen and phenylacetylene stimulated in situ methane oxidation while minimizing nitrous oxide production. Molecular analyses also indicated that methane-oxidizing bacteria may play a significant role in not only removing methane, but in nitrous oxide production as well, although the contribution of ammonia-oxidizing archaea to nitrous oxide production can not be excluded at this time. Future efforts to control both methane and nitrous oxide emissions from landfills as well as from other environments (e.g., agricultural soils) should consider these issues. Finally, a methanotrophic biofiltration system was designed and modeled for the promotion of methanotrophic activity in local methane 'hotspots' such as landfills. Model results as well as economic analyses of these biofilters indicate that the use of methanotrophic biofilters for controlling methane emissions is technically feasible, and provided either the costs of biofilter construction and operation are reduced or the value of CO{sub 2} credits is increased, can also be economically attractive.

  18. Catalytically upgraded landfill gas as a cost-effective alternative for fuel cells

    NASA Astrophysics Data System (ADS)

    Urban, W.; Lohmann, H.; Gómez, J. I. Salazar

    The potential use of landfill gas as feeding fuel for the so-called molten carbonate fuel cells (MCFC) imposes the need for new upgrading technologies in order to meet the much tougher feed gas specifications of this type of fuel cells in comparison to gas engines. Nevertheless, MCFC has slightly lower purity demands than low temperature fuel cells. This paper outlines the idea of a new catalytic purification process for landfill gas conditioning, which may be supposed to be more competitive than state-of-the-art technologies and summarises some lab-scale results. This catalytic process transforms harmful landfill gas minor compounds into products that can be easily removed from the gas stream by a subsequent adsorption step. The optimal process temperature was found to be in the range 250-400 °C. After a catalyst screening, two materials were identified, which have the ability to remove all harmful minor compounds from landfill gas. The first material was a commercial alumina that showed a high activity towards the removal of organic silicon compounds. The alumina protects both a subsequent catalyst for the removal of other organic minor compounds and the fuel cell. Due to gradual deactivation caused by silica deposition, the activated alumina needs to be periodically replaced. The second material was a commercial V 2O 5/TiO 2-based catalyst that exhibited a high activity for the total oxidation of a broad spectrum of other harmful organic minor compounds into a simpler compound class "acid gases (HCl, HF and SO 2)", which can be easily removed by absorption with, e.g. alkalised alumina. The encouraging results obtained allow the scale-up of this LFG conditioning process to test it under real LFG conditions.

  19. The impact of landfilling and composting on greenhouse gas emissions--a review.

    PubMed

    Lou, X F; Nair, J

    2009-08-01

    Municipal solid waste is a significant contributor to greenhouse gas emissions through decomposition and life-cycle activities processes. The majority of these emissions are a result of landfilling, which remains the primary waste disposal strategy internationally. As a result, countries have been incorporating alternative forms of waste management strategies such as energy recovery from landfill gas capture, aerobic landfilling (aerox landfills), pre-composting of waste prior to landfilling, landfill capping and composting of the organic fraction of municipal solid waste. As the changing global climate has been one of the major environmental challenges facing the world today, there is an increasing need to understand the impact of waste management on greenhouse gas emissions. This review paper serves to provide an overview on the impact of landfilling (and its various alternatives) and composting on greenhouse gas emissions taking into account streamlined life cycle activities and the decomposition process. The review suggests greenhouse gas emissions from waste decomposition are considerably higher for landfills than composting. However, mixed results were found for greenhouse gas emissions for landfill and composting operational activities. Nonetheless, in general, net greenhouse gas emissions for landfills tend to be higher than that for composting facilities.

  20. Methane production from food waste leachate in laboratory-scale simulated landfill.

    PubMed

    Behera, Shishir Kumar; Park, Jun Mo; Kim, Kyeong Ho; Park, Hung-Suck

    2010-01-01

    Due to the prohibition of food waste landfilling in Korea from 2005 and the subsequent ban on the marine disposal of organic sludge, including leachate generated from food waste recycling facilities from 2012, it is urgent to develop an innovative and sustainable disposal strategy that is eco-friendly, yet economically beneficial. In this study, methane production from food waste leachate (FWL) in landfill sites with landfill gas recovery facilities was evaluated in simulated landfill reactors (lysimeters) for a period of 90 d with four different inoculum-substrate ratios (ISRs) on volatile solid (VS) basis. Simultaneous biochemical methane potential batch experiments were also conducted at the same ISRs for 30 d to compare CH(4) yield obtained from lysimeter studies. Under the experimental conditions, a maximum CH(4) yield of 0.272 and 0.294 L/g VS was obtained in the batch and lysimeter studies, respectively, at ISR of 1:1. The biodegradability of FWL in batch and lysimeter experiments at ISR of 1:1 was 64% and 69%, respectively. The calculated data using the modified Gompertz equation for the cumulative CH(4) production showed good agreement with the experimental result obtained from lysimeter study. Based on the results obtained from this study, field-scale pilot test is required to re-evaluate the existing sanitary landfills with efficient leachate collection and gas recovery facilities as engineered bioreactors to treat non-hazardous liquid organic wastes for energy recovery with optimum utilization of facilities. PMID:20227867

  1. Fate of plasticised PVC products under landfill conditions: a laboratory-scale landfill simulation reactor study.

    PubMed

    Mersiowsky, I; Weller, M; Ejlertsson, J

    2001-09-01

    The long-term behaviour of plasticised PVC products was investigated in laboratory-scale landfill simulation reactors. The examined products included a cable material and a flooring with different combinations of plasticisers. The objective of the study was to assess whether a degradation of the PVC polymer or a loss of plasticisers occurred under landfill conditions. A degradation of the polymer matrix was not observed. The contents of plasticisers in aged samples was determined and compared to the respective original products. The behaviour of the various plasticisers was found to differ significantly. Losses of DEHP and BBP from the flooring were too low for analytical quantification. No loss of DIDP from the cable was detectable, whereas DINA in the same product showed considerable losses of up to 70% compared to the original contents. These deficits were attributable to biodegradation rather than leaching. There was no equivalent release of plasticisers into the leachate. PMID:11487101

  2. Comparison of green-house gas emission reductions and landfill gas utilization between a landfill system and an incineration system.

    PubMed

    Haibin Han; Jisheng Long; Shude Li; Guangren Qian

    2010-04-01

    Electricity generation and greenhouse gas (GHG) reductions were researched by making comparisons between municipal solid waste (MSW) landfill and incineration systems with three different electricity generation efficiencies - 10%, 21%, and 24.7%. For MSW landfill systems, it is shown that the total electricity generation is 198,747 MWh, and the total GHG emission reduction is 1,386,081 tonne CO( 2) during a 21-year operation period. For incineration systems, the total electricity generation is 611,801 MWh, and the total GHG emission reduction is 1,339,158 tonne CO(2) during a 10-year operation period even if the electricity generation efficiency is only 10%. It is also shown that electricity generation increases quicker than the GHG emission reductions with the increase of electricity generation efficiency. However, incineration systems show great superiority in LFG utilisation and GHG emission reductions.

  3. Lateral gas transport in soil adjacent to an old landfill: factors governing gas migration.

    PubMed

    Christophersen, M; Kjeldsen, P

    2001-12-01

    Field experiments investigating lateral gas transport in soil adjacent to an old landfill in Denmark during a one-year period were conducted. A significant seasonal variation, with low concentrations of methane and high concentrations of carbon dioxide in the summer, caused by methane oxidation was observed. There was a good correlation between pressure above the barometric pressure and the methane concentration in the soil, indicating that advective flow was the controlling process. This was confirmed by calculations. Diurnal measurement during a drop in barometric pressure showed that lateral migration of landfill gas was a very dynamic system and the concentrations of LFG at a specific place and depth changed dramatically within a very short time. The experiments showed that change in barometric pressure was an important factor affecting gas migration at the Skellingsted landfill in Denmark.

  4. Development of the utilization of combustible gas produced in existing sanitary landfills: effects of corrosion at the Mountain View, CA Landfill Gas-Recovery Plant

    SciTech Connect

    Not Available

    1982-10-01

    Corrosion of equipment has occurred at the Mountain View, California Landfill Gas Recovery Plant. Corrosion is most severe on compressor valve seats and cages, tubes in the first and second stages of the interstage gas cooler, and first and second stage piping and liquid separators. Corrosion occurs because the raw landfill gas contains water, carbon dioxide, and oxygen. Some corrosion may also result from trace concentrations of organic acids present in the landfill gas. Corrosion of the third stage compressor, cooler, and piping does not occur because the gas is dehydrated immediately prior to the third stage. Controlling corrosion is necessary to maintain the mechanical integrity of the plant and to keep the cost of the gas competitive with natural gas. Attempts to reduce corrosion rates by injecting a chemical inhibitor have proved only partially successful. Recommendations for dealing with corrosion include earlier dehydration of the gas, selection of special alloys in critical locations, chemical inhibition, and regular plant inspections.

  5. LANDFILL GAS EMISSIONS MODEL (LANDGEM) VERSION 3.02 USER'S GUIDE

    EPA Science Inventory

    The Landfill Gas Emissions Model (LandGEM) is an automated estimation tool with a Microsoft Excel interface that can be used to estimate emission rates for total landfill gas, methane, carbon dioxide, nonmethane organic compounds, and individual air pollutants from municipal soli...

  6. Improved methodology to assess modification and completion of landfill gas management in the aftercare period

    SciTech Connect

    Morris, Jeremy W.F.; Crest, Marion; Barlaz, Morton A.; Spokas, Kurt A.; Akerman, Anna; Yuan, Lei

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Performance-based evaluation of landfill gas control system. Black-Right-Pointing-Pointer Analytical framework to evaluate transition from active to passive gas control. Black-Right-Pointing-Pointer Focus on cover oxidation as an alternative means of passive gas control. Black-Right-Pointing-Pointer Integrates research on long-term landfill behavior with practical guidance. - Abstract: Municipal solid waste landfills represent the dominant option for waste disposal in many parts of the world. While some countries have greatly reduced their reliance on landfills, there remain thousands of landfills that require aftercare. The development of cost-effective strategies for landfill aftercare is in society's interest to protect human health and the environment and to prevent the emergence of landfills with exhausted aftercare funding. The Evaluation of Post-Closure Care (EPCC) methodology is a performance-based approach in which landfill performance is assessed in four modules including leachate, gas, groundwater, and final cover. In the methodology, the objective is to evaluate landfill performance to determine when aftercare monitoring and maintenance can be reduced or possibly eliminated. This study presents an improved gas module for the methodology. While the original version of the module focused narrowly on regulatory requirements for control of methane migration, the improved gas module also considers best available control technology for landfill gas in terms of greenhouse gas emissions, air quality, and emissions of odoriferous compounds. The improved module emphasizes the reduction or elimination of fugitive methane by considering the methane oxidation capacity of the cover system. The module also allows for the installation of biologically active covers or other features designed to enhance methane oxidation. A methane emissions model, CALMIM, was used to assist with an assessment of the methane oxidation capacity of

  7. Analysis of a landfill gas to energy system at the municipal solid waste landfill in Gaziantep, Turkey.

    PubMed

    Tercan, Safak Hengirmen; Cabalar, Ali Firat; Yaman, Gokhan

    2015-08-01

    This paper presents an analysis of the electricity generation from municipal solid waste (MSW), via landfill gas valorization technology, at the landfill of Gaziantep City, Turkey. Rapid increase in population, and industrial developments, throughout the world including Turkey results in larger amount of waste materials generated, increased need for energy, and adverse affects on the environment and human health. Turkey plans to produce 1/3 of its electricity demand using renewable energy sources by the year of 2023. It is recommended to use each year around 25 million tonnes of the MSW generated nationwide for a renewable energy supply. In this study, a concise summary of current status of electricity generation from a MSW landfill gas plant (via biogas harnessing) located in Gaziantep City was analyzed as a case study.

  8. Numerical modeling of landfill gas and heat transport in the deformable MSW landfill body. Part 1. Development of the model

    NASA Astrophysics Data System (ADS)

    Kutsyi, D. V.

    2015-06-01

    The article is devoted to studying the parameters of wells that are used as part of vertical gas extraction systems for degassing landfills. To this end, approaches to modeling the main processes occurring in the landfill's porous medium are considered. The considered approaches served as a basis for elaborating a thermophysical gas and heat transport model that takes into account variation in the hydrodynamic properties of wastes resulting from their secondary settlement. The adequacy of the results obtained using the developed model is confirmed by the data of classic works. The effect the secondary settlement of wastes has on the distribution of pressure and temperature in the landfill body is determined. It is shown that compaction of wastes due to their secondary settlement results in a growth of pressure by 40% on the average.

  9. Greenhouse gas emissions from landfill leachate treatment plants: a comparison of young and aged landfill.

    PubMed

    Wang, Xiaojun; Jia, Mingsheng; Chen, Xiaohai; Xu, Ying; Lin, Xiangyu; Kao, Chih Ming; Chen, Shaohua

    2014-07-01

    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 CH4 emissions were observed from the fresh leachate storage pond, with the fluxes values (2219-26,489 mg Cm(-2)h(-1)) extremely higher than those of N2O (0.028-0.41 mg Nm(-2)h(-1)). In contrast, the emission values for both CH4 and N2O were low for the aged leachate tank. N2O 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 N2O emission based on both leachate treatment systems was estimated to be 7.99 g N2O-N capita(-1)yr(-1). An increase of 80% in N2O emissions was observed when the bioreactor pH decreased by approximately 1 pH unit. The vast majority of carbon was removed in the form of CO2, with a small portion as CH4 (<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(2) eq yr(-1), respectively, for a total that could be transformed to 9.09 kg CO(2) eq capita(-1)yr(-1).

  10. Comparison between landfill gas and waste incineration for power generation in Astana, Kazakhstan.

    PubMed

    Inglezakis, Vassilis J; Rojas-Solórzano, Luis; Kim, Jong; Aitbekova, Aisulu; Ismailova, Aizada

    2015-05-01

    The city of Astana, the capital of Kazakhstan, which has a population of 804,474, and has been experiencing rapid growth over the last 15 years, generates approximately 1.39 kg capita(-1) day(-1) of municipal solid waste (MSW). Nearly 700 tonnes of MSW are collected daily, of which 97% is disposed of at landfills. The newest landfill was built using modern technologies, including a landfill gas (LFG) collection system.The rapid growth of Astana demands more energy on its path to development, and the viability analysis of MSW to generate electricity is imperative. This paper presents a technical-economic pre-feasibility study comparing landfill including LFG utilization and waste incineration (WI) to produce electricity. The performance of LFG with a reciprocating engine and WI with steam turbine power technologies were compared through corresponding greenhouse gases (GHG) reduction, cost of energy production (CEP), benefit-cost ratio (BCR), net present value (NPV) and internal rate of return (IRR) from the analyses. Results demonstrate that in the city of Astana, WI has the potential to reduce more than 200,000 tonnes of GHG per year, while LFG could reduce slightly less than 40,000 tonnes. LFG offers a CEP 5.7% larger than WI, while the latter presents a BCR two times higher than LFG. WI technology analysis depicts a NPV exceeding 280% of the equity, while for LFG, the NPV is less than the equity, which indicates an expected remarkable financial return for the WI technology and a marginal and risky scenario for the LFG technology. Only existing landfill facilities with a LFG collection system in place may turn LFG into a viable project.

  11. Comparison between landfill gas and waste incineration for power generation in Astana, Kazakhstan.

    PubMed

    Inglezakis, Vassilis J; Rojas-Solórzano, Luis; Kim, Jong; Aitbekova, Aisulu; Ismailova, Aizada

    2015-05-01

    The city of Astana, the capital of Kazakhstan, which has a population of 804,474, and has been experiencing rapid growth over the last 15 years, generates approximately 1.39 kg capita(-1) day(-1) of municipal solid waste (MSW). Nearly 700 tonnes of MSW are collected daily, of which 97% is disposed of at landfills. The newest landfill was built using modern technologies, including a landfill gas (LFG) collection system.The rapid growth of Astana demands more energy on its path to development, and the viability analysis of MSW to generate electricity is imperative. This paper presents a technical-economic pre-feasibility study comparing landfill including LFG utilization and waste incineration (WI) to produce electricity. The performance of LFG with a reciprocating engine and WI with steam turbine power technologies were compared through corresponding greenhouse gases (GHG) reduction, cost of energy production (CEP), benefit-cost ratio (BCR), net present value (NPV) and internal rate of return (IRR) from the analyses. Results demonstrate that in the city of Astana, WI has the potential to reduce more than 200,000 tonnes of GHG per year, while LFG could reduce slightly less than 40,000 tonnes. LFG offers a CEP 5.7% larger than WI, while the latter presents a BCR two times higher than LFG. WI technology analysis depicts a NPV exceeding 280% of the equity, while for LFG, the NPV is less than the equity, which indicates an expected remarkable financial return for the WI technology and a marginal and risky scenario for the LFG technology. Only existing landfill facilities with a LFG collection system in place may turn LFG into a viable project. PMID:25819927

  12. Tapping Landfill Gas to Provide Significant Energy Savings and Greenhouse Gas Reductions - Case Study

    SciTech Connect

    2013-04-30

    BroadRock Renewables, LLC built two high efficiency electricity generating facilities that utilize landfill gas in California and Rhode Island. The two projects received a total of $25 million in U.S. Department of Energy funding from the American Recovery and Reinvestment Act (ARRA) of 2009. Private-sector cost share for the projects totaled approximately $186 million.

  13. Greenhouse gas emissions during MSW landfilling in China: influence of waste characteristics and LFG treatment measures.

    PubMed

    Yang, Na; Zhang, Hua; Shao, Li-Ming; Lü, Fan; He, Pin-Jing

    2013-11-15

    Reducing greenhouse gas (GHG) emissions from municipal solid waste (MSW) treatment can be highly cost-effective in terms of GHG mitigation. This study investigated GHG emissions during MSW landfilling in China under four existing scenarios and in terms of seven different categories: waste collection and transportation, landfill management, leachate treatment, fugitive CH4 (FM) emissions, substitution of electricity production, carbon sequestration and N2O and CO emissions. GHG emissions from simple sanitary landfilling technology where no landfill gas (LFG) extraction took place (Scenario 1) were higher (641-998 kg CO2-eq·t(-1)ww) than those from open dump (Scenario 0, 480-734 kg CO2-eq·t(-1)ww). This was due to the strictly anaerobic conditions in Scenario 1. LFG collection and treatment reduced GHG emissions to 448-684 kg CO2-eq·t(-1)ww in Scenario 2 (with LFG flare) and 214-277 kg CO2-eq·t(-1)ww in Scenario 3 (using LFG for electricity production). Amongst the seven categories, FM was the predominant contributor to GHG emissions. Global sensitivity analysis demonstrated that the parameters associated with waste characteristics (i.e. CH4 potential and carbon sequestered faction) and LFG management (i.e. LFG collection efficiency and CH4 oxidation efficiency) were of great importance. A further learning on the MSW in China indicated that water content and dry matter content of food waste were the basic factors affecting GHG emissions. Source separation of food waste, as well as increasing the incineration ratio of mixed collected MSW, could effectively mitigate the overall GHG emissions from landfilling in a specific city. To increase the LFG collection and CH4 oxidation efficiencies could considerably reduce GHG emissions on the landfill site level. While, the improvement in the LFG utilization measures had an insignificant impact as long as the LFG is recovered for energy generation. PMID:24018116

  14. Using a Gas-Phase Tracer Test to Characterize the Impact of Landfill Gas Generation on Advective-Dispersive Transport of VOCs in the Vadose Zone

    PubMed Central

    Monger, Gregg R.; Duncan, Candice Morrison; Brusseau, Mark L.

    2015-01-01

    A gas-phase tracer test (GTT) was conducted at a landfill in Tucson, AZ, to help elucidate the impact of landfill gas generation on the transport and fate of chlorinated aliphatic volatile organic contaminants (VOCs). Sulfur hexafluoride (SF6) was used as the non-reactive gas tracer. Gas samples were collected from a multiport monitoring well located 15.2 m from the injection well, and analyzed for SF6, CH4, CO2, and VOCs. The travel times determined for SF6 from the tracer test are approximately two to ten times smaller than estimated travel times that incorporate transport by only gas-phase diffusion. In addition, significant concentrations of CH4 and CO2 were measured, indicating production of landfill gas. Based on these results, it is hypothesized that the enhanced rates of transport observed for SF6 are caused by advective transport associated with landfill gas generation. The rates of transport varied vertically, which is attributed to multiple factors including spatial variability of water content, refuse mass, refuse permeability, and gas generation. PMID:26380532

  15. Control of gas from landfills and/or marsh areas

    SciTech Connect

    Hanson, E.H.

    1997-12-31

    Landfills are the most well known source of methane formed by decomposition of organic material, but the authors have found that marsh gas generated by peat deposits also contain large quantities of methane and often become a formidable hazard. This is particularly true when small amounts of refuse or ground wood fill (hog fuel) has been placed on the marsh area to raise the ground elevation. It is well known that there is a natural propensity for methane generation and explosion from municipal solid waste landfills and marshlands. Despite this fact, in the Vancouver area, large, high value land development projects are taking place adjacent to methane generation areas and directly upon them. This is due to rapid growth and the consequent high demand for serviced building lots. Consequently, it became necessary to develop soils gas eradication systems which totally eliminate any danger of methane accumulation in buildings, in waste water and land drainage piping, and in underground electrical and telephone conduits. This was accomplished for a high caliber industrial/commercial site in Coquitlam, B.C. known as Pacific Reach Business Park. The site consists of about 180 acres and is underlain by peat and silt. It then became the recipient of municipal solid waste and ground wood waste (hog fuel), all of which produce methane. Finally it was topped with clay and dredged sand from the Fraser River. The biodegradation of carbon from the refuse plus the cellulose from the wood waste generated high volumes of methane. All of the underground municipal, telephone, and electrical conduits are protected from methane intrusion by a city-owned methane eradication system funded by the developer. The buildings each have built-in, custom designed, protection systems. Development is about 75% completed.

  16. The decomposition of wood products in landfills in Sydney, Australia.

    PubMed

    Ximenes, F A; Gardner, W D; Cowie, A L

    2008-11-01

    Three landfill sites that had been closed for 19, 29 and 46 years and had been operated under different management systems were excavated in Sydney. The mean moisture content of the wood samples ranged from 41.6% to 66.8%. The wood products recovered were identified to species, and their carbon, cellulose, hemicellulose and lignin concentration were determined and compared to those of matched samples of the same species. No significant loss of dry mass was measured in wood products buried for 19 and 29 years, but where refuse had been buried for 46 years, the measured loss of carbon (as a percentage of dry biomass) was 8.7% for hardwoods and 9.1% for softwoods, equating to 18% and 17% of their original carbon content, respectively. The results indicate that published decomposition factors based on laboratory research significantly overestimate the decomposition of wood products in landfill. PMID:18178075

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

    SciTech Connect

    Wang, Xiaojun; Jia, Mingsheng; Chen, Xiaohai; Xu, Ying; Lin, Xiangyu; Kao, Chih Ming; Chen, Shaohua

    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}.

  18. Landfill Gas Energy Cost Model Version 3.0 (LFGcost-Web V3.0)

    EPA Science Inventory

    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 landfil...

  19. U.S. EPA'S FIELD TEST PROGRAMS TO UPDATE DATA ON LANDFILL GAS EMISSIONS

    EPA Science Inventory

    The paper discusses a field test program in which the EPA is currently engaged to improve data on landfill gas (LFG) emissions. LFG emissions data in use at this time are based on determinations made in the late 1980s and early 1990s; changes in landfill operations, such as using...

  20. Energy potential of modern landfills

    SciTech Connect

    Bogner, J.E.

    1990-01-01

    Methane produced by refuse decomposition in a sanitary landfill can be recovered for commercial use. Landfill methane is currently under-utilized, with commercial recovery at only a small percentage of US landfills. New federal regulations mandating control of landfill gas migration and atmospheric emissions are providing impetus to methane recovery schemes as a means of recovering costs for increased environmental control. The benefits of landfill methane recovery include utilization of an inexpensive renewable energy resource, removal of explosive gas mixtures from the subsurface, and mitigation of observed historic increases in atmospheric methane. Increased commercial interest in landfill methane recovery is dependent on the final form of Clean Air Act amendments pertaining to gaseous emissions from landfills; market shifts in natural gas prices; financial incentives for development of renewable energy resources; and support for applied research and development to develop techniques for increased control of the gas generation process in situ. This paper will discuss the controls on methane generation in landfills. In addition, it will address how landfill regulations affect landfill design and site management practices which, in turn, influence decomposition rates. Finally, future trends in landfilling, and their relationship to gas production, will be examined. 19 refs., 2 figs., 3 tabs.

  1. Estimates of solid waste disposal rates and reduction targets for landfill gas emissions

    NASA Astrophysics Data System (ADS)

    Powell, Jon T.; Townsend, Timothy G.; Zimmerman, Julie B.

    2016-02-01

    Landfill disposal of municipal solid waste represents one of the largest anthropogenic global methane emission sources, and recent policy approaches have targeted significant reductions of these emissions to combat climate change in the US (ref. ). The efficacy of active gas collection systems in the US was examined by analysing performance data, including fire occurrence, from more than 850 landfills. A generalized linear model showed that the operating status of a landfill--open and actively receiving waste or closed--was the most significant predictor of collection system performance. Gas collection systems at closed landfills were statistically significantly more efficient (p < 0.001) and on average 17 percentage points more efficient than those at open landfills, but open landfills were found to represent 91% of all landfill methane emissions. These results demonstrate the clear need to target open landfills to achieve significant near-term methane emission reductions. This observation is underscored by landfill disposal rates in the US significantly exceeding previously reported national estimates, with this study reporting 262 million tonnes in the year 2012 compared with 122 million tonnes in 2012 as estimated by the US Environmental Protection Agency.

  2. Effects of a temporary HDPE cover on landfill gas emissions: multiyear evaluation with the static chamber approach at an Italian landfill.

    PubMed

    Capaccioni, Bruno; Caramiello, Cristina; Tatàno, Fabio; Viscione, Alessandro

    2011-05-01

    According to the European Landfill Directive 1999/31/EC and the related Italian Legislation ("D. Lgs. No. 36/2003"), monitoring and control procedures of landfill gas emissions, migration and external dispersions are clearly requested. These procedures could be particularly interesting in the operational circumstance of implementing a temporary cover, as for instance permitted by the Italian legislation over worked-out landfill sections, awaiting the evaluation of expected waste settlements. A possible quantitative approach for field measurement and consequential evaluation of landfill CO(2), CH(4) emission rates in pairs consists of the static, non-stationary accumulation chamber technique. At the Italian level, a significant and recent situation of periodical landfill gas emission monitoring is represented by the sanitary landfill for non-hazardous waste of the "Fano" town district, where monitoring campaigns with the static chamber have been annually conducted during the last 5 years (2005-2009). For the entire multiyear monitoring period, the resulting CO(2), CH(4) emission rates varied on the whole up to about 13,100g CO(2) m(-2)d(-1) and 3800 g CH(4) m(-2)d(-1), respectively. The elaboration of these landfill gas emission data collected at the "Fano" case-study site during the monitoring campaigns, presented and discussed in the paper, gives rise to a certain scientific evidence of the possible negative effects derivable from the implementation of a temporary HDPE cover over a worked-out landfill section, notably: the lateral migration and concentration of landfill gas emissions through adjacent, active landfill sections when hydraulically connected; and consequently, the increase of landfill gas flux velocities throughout the reduced overall soil cover surface, giving rise to a flowing through of CH(4) emissions without a significant oxidation. Thus, these circumstances are expected to cause a certain increase of the overall GHG emissions from the given

  3. Measurements of methane emissions from landfills using mobile plume method with trace gas and cavity ring-down spectroscopy

    NASA Astrophysics Data System (ADS)

    Mønster, J.; Kjeldsen, P.; Scheutz, C.

    2012-04-01

    Methane is emitted to the atmosphere from both anthropogenic and natural sources. One of the major anthropogenic sources is methane produced by bacteria in anaerobic environments such as rice pads and landfills. Land filling has for many years been the preferred waste disposal method, resulting in a large methane production with a large contribution to the global increase in atmospheric green house gas concentration. Several steps have been taken to reduce the emission of methane from landfills. In order to validate the effect of these steps, a measurement method is needed to quantify methane emissions with a large spatial variation. One method is to use a highly sensitive and fast analytical method, capable of measuring the atmospheric concentration methane downwind from emission areas. Combined with down-wind measurements of a trace gas, emitted at a controlled mass flow rate, the methane emission can be calculated. This method is called the mobile plume method, as the whole plume is measured by doing several transects. In the current study a methane/acetylene analyzer with cavity ring-down spectroscopy detection (Picarro, G2203) was used to estimate methane from a number of Danish landfills. We measured at both active and closed landfills and investigated the difference in methane emission. At landfills where the emissions could have more than one origin, the source strength of the different emission areas was determined by accurate trace gas positioning and choosing appropriate wind speed and measurement distance. To choose these factors, we addressed the uncertainties and limitations of the method with respect to the configuration of the trace gas bottles and the distance between the emission area and the measurement points. Composting of organic material in large piles was done at several of the investigated landfills and where possible, the methane emission from this partly anaerobic digestion was measured as a separate emission.

  4. Evaluation of Partitioning Gas Tracer Tests for Measuring Water in Landfills

    NASA Astrophysics Data System (ADS)

    Imhoff, P. T.; Han, B.; Jafarpour, Y.; Gallagher, V. N.; Chiu, P. C.; Fluman, D. A.; Vasuki, N. C.; Yazdani, R.; Augenstein, D.; Cohen, K. K.

    2003-12-01

    Methane is an important greenhouse gas, and landfills are the largest anthropogenic source in many developed countries. Bioreactor landfills have been proposed as one means of abating greenhouse gas emissions from landfills. Here, the decomposition of organic wastes is enhanced by the controlled addition of water or leachate to maintain optimal conditions for waste decomposition. Greenhouse gas abatement is accomplished by sequestration of photosynthetically derived carbon in wastes, CO2 offsets from energy use of waste derived gas, and mitigation of methane emission from the wastes. An important issue in the operation of bioreactor landfills is knowing how much water to add and where to add it. Accurate methods for measuring the amount of water in landfills would be valuable aids for implementing leachate recirculation systems. Current methods for measuring water are inadequate, though, since they provide point measurements and are frequently affected by heterogeneity of the solid waste composition and solid waste compaction. The value of point measurements is significantly reduced in systems where water flows preferentially, such as in landfills. Here, spatially integrated measurements might be of greater value. We are evaluating a promising technology, the partitioning gas tracer test, to measure the water saturation within landfills, the amount of free water in solid waste divided by the volume of the voids. The partitioning gas tracer test was recently developed by researchers working in the vadose zone. We report the results from laboratory and field tests designed to evaluate the partitioning gas tracer test within an anaerobic landfill operated by the Delaware Solid Waste Authority. Vertical wells were installed within the landfill to inject and extract tracer gases. Gas flow and tracer gas movement in the solid waste were controlled by the landfill's existing gas collection system, which included vertical wells installed throughout the landfill through

  5. GUIDANCE FOR EVALUATING LANDFILL GAS EMISSIONS FROM CLOSED OR ABANDONED FACILITIES

    EPA Science Inventory

    This document provides guidance to Superfund remedial project managers, on scene coordinators, facility owners, and potentially responsible parties for conducting an air pathway analysis for landfill gas (LFG) emissions under the Comprehensive Environmental Response, Compensation...

  6. Photoacoustic infrared spectroscopy for conducting gas tracer tests and measuring water saturations in landfills

    SciTech Connect

    Jung, Yoojin; Han, Byunghyun; Mostafid, M. Erfan; Chiu, Pei; Yazdani, Ramin; Imhoff, Paul T.

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Photoacoustic infrared spectroscopy tested for measuring tracer gas in landfills. Black-Right-Pointing-Pointer Measurement errors for tracer gases were 1-3% in landfill gas. Black-Right-Pointing-Pointer Background signals from landfill gas result in elevated limits of detection. Black-Right-Pointing-Pointer Technique is much less expensive and easier to use than GC. - Abstract: Gas tracer tests can be used to determine gas flow patterns within landfills, quantify volatile contaminant residence time, and measure water within refuse. While gas chromatography (GC) has been traditionally used to analyze gas tracers in refuse, photoacoustic spectroscopy (PAS) might allow real-time measurements with reduced personnel costs and greater mobility and ease of use. Laboratory and field experiments were conducted to evaluate the efficacy of PAS for conducting gas tracer tests in landfills. Two tracer gases, difluoromethane (DFM) and sulfur hexafluoride (SF{sub 6}), were measured with a commercial PAS instrument. Relative measurement errors were invariant with tracer concentration but influenced by background gas: errors were 1-3% in landfill gas but 4-5% in air. Two partitioning gas tracer tests were conducted in an aerobic landfill, and limits of detection (LODs) were 3-4 times larger for DFM with PAS versus GC due to temporal changes in background signals. While higher LODs can be compensated by injecting larger tracer mass, changes in background signals increased the uncertainty in measured water saturations by up to 25% over comparable GC methods. PAS has distinct advantages over GC with respect to personnel costs and ease of use, although for field applications GC analyses of select samples are recommended to quantify instrument interferences.

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

    NASA Astrophysics Data System (ADS)

    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 ( < 3 km2 footprints) and high accuracy ( 0.5 to 3 ppm) CO2 measurements. The original OCO satellite failed to achieve orbit in February 2009. A replacement satellite (OCO-2) is under construction and scheduled for launch in February 2013. These characteristics will allow the measurement of CO2 emissions from large landfills on the orbit path. Because surface landfill gas emissions include both CH4 and CO2 , the CH4 concentration can be inferred from CO2 concentrations. The CarbonSAT satellite which is being designed by the University of Bremen, Institute for Environmental Physics, has similar characteristics to OCO-2 but it has been optimized for measurement of both CH4 and CO2 . Key specifications for the CarbonSAT satellite include XCO2 single measurement error of < 1 to 3 ppm and XCH4 single measurement error of < 10 to 18 ppb. These characteristics will make it possible to detect both CO2 and CH4 emissions from large landfills. The spatial resolution and accuracy of the CO2 measurements from OCO-2 and CO2 and CH4 measurements from CarbonSAT present a unique opportunity to measure landfill gas emissions from large landfills such as exist in the United States and other developed countries. In general, landfills in the developed countries have

  8. Emission assessment at the Burj Hammoud inactive municipal landfill: Viability of landfill gas recovery under the clean development mechanism

    SciTech Connect

    El-Fadel, Mutasem; Abi-Esber, Layale; Salhab, Samer

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer LFG emissions are measured at an abandoned landfill with highly organic waste. Black-Right-Pointing-Pointer Mean headspace and vent emissions are 0.240 and 0.074 l CH{sub 4}/m{sup 2} hr, respectively. Black-Right-Pointing-Pointer At sites with high food waste content, LFG generation drops rapidly after site closure. Black-Right-Pointing-Pointer The viability of LFG recovery for CDMs in developing countries is doubtful. - Abstract: This paper examines landfill gas (LFG) emissions at a large inactive waste disposal site to evaluate the viability of investment in LFG recovery through the clean development mechanism (CDM) initiative. For this purpose, field measurements of LFG emissions were conducted and the data were processed by geospatial interpolation to estimate an equivalent site emission rate which was used to calibrate and apply two LFG prediction models to forecast LFG emissions at the site. The mean CH{sub 4} flux values calculated through tessellation, inverse distance weighing and kriging were 0.188 {+-} 0.014, 0.224 {+-} 0.012 and 0.237 {+-} 0.008 l CH{sub 4}/m{sup 2} hr, respectively, compared to an arithmetic mean of 0.24 l/m{sup 2} hr. The flux values are within the reported range for closed landfills (0.06-0.89 l/m{sup 2} hr), and lower than the reported range for active landfills (0.42-2.46 l/m{sup 2} hr). Simulation results matched field measurements for low methane generation potential (L{sub 0}) values in the range of 19.8-102.6 m{sup 3}/ton of waste. LFG generation dropped rapidly to half its peak level only 4 yrs after landfill closure limiting the sustainability of LFG recovery systems in similar contexts and raising into doubt promoted CDM initiatives for similar waste.

  9. Landfill-gas-to-Energy projects: analysis of net private and social benefits.

    PubMed

    Jaramillo, Paulina; Matthews, H Scott

    2005-10-01

    Methane emissions from municipal landfills represent 3% of the total United States greenhouse gas emissions that contribute to climate change. These methane emissions can be released to the air or collected and flared. This landfill gas also has the potential to be used to generate electricity. In 1994,the Environmental Protection Agency(EPA) created the Landfill Methane Outreach Program, with the objective of promoting the development of landfill-gas-to-energy projects around the country. There are currently 2,300 active landfills in the United States. Although there are already 382 operational projects, there are many more landfills with the potential to use the gas. EPA has identified at least 630 candidate landfills for energy projects, and many more have still not been identified. The objective of this paper is to evaluate total private and social benefits of landfill-gas-to-energy projects, taking into consideration not only the costs of installing and maintaining the necessary equipment and the revenues obtained from selling the electricity but also a valuation of the greenhouse gas emissions that would be prevented and the emissions of criteria pollutants created by the electricity generating equipment. It also evaluates the breakeven government subsidies that would be required to make such projects economically viable from private and social perspectives in comparison to current subsidies. It was found that the private breakeven price of electricity for these projects is lower than dollar 0.04/kWh. Moreover, the optimum social subsidywas found to be less than dollar 0.0085/ kWh, which is about 40% lower than the currently available federal tax break of dollar 0.015/kWh. The method developed for this paper can be applied to other renewable energy technologies, to show their relative social costs and benefits.

  10. Landfill gas effects on groundwater samples at a municipal solid waste facility.

    PubMed

    Kerfoot, H B

    1994-11-01

    A study was performed to determine the source of low concentrations of volatile organic compounds (VOCs) detected in groundwater samples at a solid waste management facility. The affected wells were identified as hydraulically upgradient of an old unlined facility, but downgradient of a new clay-lined landfill. These monitoring wells are close to both sites. Subsurface landfill gas migration was identified after a low permeability cap was installed on the older site. Subsurface gas pressure was monitored to identify horizontal landfill gas migration. Monitoring well headspace gases were evaluated to identify depressed oxygen concentrations and methane because of landfill gas migration into the well. Monitoring well headspace gas VOC concentrations were compared to groundwater VOC concentrations to determine the direction of phase transfer. A ratio above 1.0 of the observed well headspace gas concentration of a VOC to the concentration that would be in equilibrium with the groundwater concentration indicates gas-to-water phase transfer within the well. For the major gas-phase and aqueous-phase VOC, cis-1,2-dichloroethene, gas-to-water phase transfer is clearly indicated from the data for two of the four wells. Fifteen other VOCs were detected in monitoring well headspace gases but not in groundwater samples from the four wells studied. Only one compound in one well was detected in the groundwater sample but not in the headspace gases, and only one compound in one well was detected in both matrices at concentrations that suggested water-to-gas phase transfer. This study suggests that if landfill gas is suspected as the source of detected VOCs, monitoring well construction and stratigraphy are important considerations when attempting to differentiate between groundwater contamination by landfill gas and contamination from other sources.

  11. Modeling the final phase of landfill gas generation from long-term observations.

    PubMed

    Tintner, Johannes; Kühleitner, Manfred; Binner, Erwin; Brunner, Norbert; Smidt, Ena

    2012-06-01

    For waste management, methane emissions from landfills and their effect on climate change are of serious concern. Current models for biogas generation that focus on the economic use of the landfill gas are usually based on first order chemical reactions (exponential decay), underestimating the long-term emissions of landfills. The presented study concentrated on the curve fitting and the quantification of the gas generation during the final degradation phase under optimal anaerobic conditions. For this purpose the long-term gas generation (240-1,830 days) of different mechanically biologically treated (MBT) waste materials was measured. In this study the late gas generation was modeled by a log-normal distribution curve to gather the maximum gas generation potential. According to the log-normal model the observed gas sum curve leads to higher values than commonly used exponential decay models. The prediction of the final phase of landfill gas generation by a fitting model provides a basis for CO(2) balances in waste management and some information to which extent landfills serve as carbon sink.

  12. Gas breakthrough and emission through unsaturated compacted clay in landfill final cover

    SciTech Connect

    Ng, C.W.W.; Chen, Z.K.; Coo, J.L.; Chen, R.; Zhou, C.

    2015-10-15

    Highlights: • Explore feasibility of unsaturated clay as a gas barrier in landfill cover. • Gas breakthrough pressure increases with clay thickness and degree of saturation. • Gas emission rate decreases with clay thickness and degree of saturation. • A 0.6 m-thick clay layer may be sufficient to meet gas emission rate limit. - Abstract: Determination of gas transport parameters in compacted clay plays a vital role for evaluating the effectiveness of soil barriers. The gas breakthrough pressure has been widely studied for saturated swelling clay buffer commonly used in high-level radioactive waste disposal facility where the generated gas pressure is very high (in the order of MPa). However, compacted clay in landfill cover is usually unsaturated and the generated landfill gas pressure is normally low (typically less than 10 kPa). Furthermore, effects of clay thickness and degree of saturation on gas breakthrough and emission rate in the context of unsaturated landfill cover has not been quantitatively investigated in previous studies. The feasibility of using unsaturated compacted clay as gas barrier in landfill covers is thus worthwhile to be explored over a wide range of landfill gas pressures under various degrees of saturation and clay thicknesses. In this study, to evaluate the effectiveness of unsaturated compacted clay to minimize gas emission, one-dimensional soil column tests were carried out on unsaturated compacted clay to determine gas breakthrough pressures at ultimate limit state (high pressure range) and gas emission rates at serviceability limit state (low pressure range). Various degrees of saturation and thicknesses of unsaturated clay sample were considered. Moreover, numerical simulations were carried out using a coupled gas–water flow finite element program (CODE-BRIGHT) to better understand the experimental results by extending the clay thickness and varying the degree of saturation to a broader range that is typical at different

  13. A CASE STUDY DEMONSTRATING U.S. EPA GUIDANCE FOR EVALUATING LANDFILL GAS EMISSIONS FROM CLOSED OR ABANDONED FACILITIES--BUSH VALLEY LANDFILL, HARFORD COUNTY, MARYLAND

    EPA Science Inventory

    The purpose of the activities described in this document is to provide a demonstration of the procedures and methodologies described within the "Guidance for Evaluating Landfill Gas Emissions from Closed or Abandoned Facilities" (Guidance). This demonstration provides an example ...

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

    NASA Astrophysics Data System (ADS)

    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.

  15. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS: PHASE II. PRETREATMENT SYSTEM PERFORMANCE MEASUREMENT

    EPA Science Inventory

    The report describes Phase II of a demonstration of the utilization of commercial phosphoric acid fuel cells to recover energy from landfill gas. This phase consisted primarily of the construction and testing of a Gas Pretreatment Unit (GPU) whose function is to remove those impu...

  16. Suitability of Tedlar gas sampling bags for siloxane quantification in landfill gas.

    PubMed

    Ajhar, M; Wens, B; Stollenwerk, K H; Spalding, G; Yüce, S; Melin, T

    2010-06-30

    Landfill or digester gas can contain man-made volatile methylsiloxanes (VMS), usually in the range of a few milligrams per normal cubic metre (Nm(3)). Until now, no standard method for siloxane quantification exists and there is controversy with respect to which sampling procedure is most suitable. This paper presents an analytical and a sampling procedure for the quantification of common VMS in biogas via GC-MS and polyvinyl fluoride (Tedlar) bags. Two commercially available Tedlar bag models are studied. One is equipped with a polypropylene valve with integrated septum, the other with a dual port fitting made from stainless steel. Siloxane recovery in landfill gas samples is investigated as a function of storage time, temperature, surface-to-volume ratio and background gas. Recovery was found to depend on the type of fitting employed. The siloxanes sampled in the bag with the polypropylene valve show high and stable recovery, even after more than 30 days. Sufficiently low detection limits below 10 microg Nm(-3) and good reproducibility can be achieved. The method is therefore well applicable to biogas, greatly facilitating sampling in comparison with other common techniques involving siloxane enrichment using sorption media.

  17. Terrestrial laser scanning for detection of landfill gas: a pilot study

    NASA Astrophysics Data System (ADS)

    Reshetyuk, Yuriy; Mårtensson, Stig-Göran

    2014-04-01

    Methane built up in landfills as a result of breaking down of organic materials can be a renewable energy source if it is taken advantage of. The aim of research presented in this paper is to detect landfill gas (that contains methane) by means of terrestrial laser scanning. The hypothesis is that where no surface leakage has been reported, the landfill gas will expand or migrate. Therefore, it is possible to detect it through repeated scanning of the same area and comparison of Digital Terrain Models (DTMs) generated from the point clouds. Only the most significant movements, i.e. vertical, are of interest in this case. During September-November 2011, a small area at Forsbacka landfill in the vicinity of Gävle was scanned 10 times. Epoch-to-epoch comparisons of the resulting DTMs have shown two significant changes (-27 and +19 mm) in elevation of the surface, and it is not impossible that they are caused by migrating landfill gas. The method tested in this study is deemed to be rigorous and accurate for detecting small-scale swell-shrink behaviour of the ground surface (in our case a landfill surface). However, both data processing and interpretation of the results have been considerably complicated by presence of low vegetation (weeds) on the study site, which was dificult to filter away completely from the data. Based on our pilot study, we recommend that a larger area and a longer period of time are chosen to give basis for more grounded conclusions about presence of landfill gas.

  18. Factors affecting water balance and percolate production for a landfill in operation.

    PubMed

    Poulsen, Tjalfe G; Møoldrup, Per

    2005-02-01

    Percolate production and precipitation data for a full-scale landfill in operation measured over a 13-year period were used to evaluate the impact and importance of the hydrological conditions of landfill sections on the percolate production rates. Both active (open) and closed landfill sections were included in the evaluation. A simple top cover model requiring a minimum of input data was used to simulate the percolate production as a function of precipitation and landfill section hydrology. The results showed that changes over time in the hydrology of individual landfill sections (such as section closure or plantation of trees on top of closed sections) can change total landfill percolate production by more than 100%; thus, percolate production at an active landfill can be very different from percolate production at the same landfill after closure. Furthermore, plantation of willow on top of closed sections can increase the evapotranspiration rate thereby reducing percolate production rates by up to 47% compared to a grass cover. This process, however, depends upon the availability of water in the top layer, and so the evaporation rate will be less than optimal during the summer where soil-water contents in the top cover are low.

  19. Gas breakthrough and emission through unsaturated compacted clay in landfill final cover.

    PubMed

    Ng, C W W; Chen, Z K; Coo, J L; Chen, R; Zhou, C

    2015-10-01

    Determination of gas transport parameters in compacted clay plays a vital role for evaluating the effectiveness of soil barriers. The gas breakthrough pressure has been widely studied for saturated swelling clay buffer commonly used in high-level radioactive waste disposal facility where the generated gas pressure is very high (in the order of MPa). However, compacted clay in landfill cover is usually unsaturated and the generated landfill gas pressure is normally low (typically less than 10 kPa). Furthermore, effects of clay thickness and degree of saturation on gas breakthrough and emission rate in the context of unsaturated landfill cover has not been quantitatively investigated in previous studies. The feasibility of using unsaturated compacted clay as gas barrier in landfill covers is thus worthwhile to be explored over a wide range of landfill gas pressures under various degrees of saturation and clay thicknesses. In this study, to evaluate the effectiveness of unsaturated compacted clay to minimize gas emission, one-dimensional soil column tests were carried out on unsaturated compacted clay to determine gas breakthrough pressures at ultimate limit state (high pressure range) and gas emission rates at serviceability limit state (low pressure range). Various degrees of saturation and thicknesses of unsaturated clay sample were considered. Moreover, numerical simulations were carried out using a coupled gas-water flow finite element program (CODE-BRIGHT) to better understand the experimental results by extending the clay thickness and varying the degree of saturation to a broader range that is typical at different climate conditions. The results of experimental study and numerical simulation reveal that as the degree of saturation and thickness of clay increase, the gas breakthrough pressure increases but the gas emission rate decreases significantly. Under a gas pressure of 10 kPa (the upper bound limit of typical landfill gas pressure), a 0.6m or thicker

  20. Gas breakthrough and emission through unsaturated compacted clay in landfill final cover.

    PubMed

    Ng, C W W; Chen, Z K; Coo, J L; Chen, R; Zhou, C

    2015-10-01

    Determination of gas transport parameters in compacted clay plays a vital role for evaluating the effectiveness of soil barriers. The gas breakthrough pressure has been widely studied for saturated swelling clay buffer commonly used in high-level radioactive waste disposal facility where the generated gas pressure is very high (in the order of MPa). However, compacted clay in landfill cover is usually unsaturated and the generated landfill gas pressure is normally low (typically less than 10 kPa). Furthermore, effects of clay thickness and degree of saturation on gas breakthrough and emission rate in the context of unsaturated landfill cover has not been quantitatively investigated in previous studies. The feasibility of using unsaturated compacted clay as gas barrier in landfill covers is thus worthwhile to be explored over a wide range of landfill gas pressures under various degrees of saturation and clay thicknesses. In this study, to evaluate the effectiveness of unsaturated compacted clay to minimize gas emission, one-dimensional soil column tests were carried out on unsaturated compacted clay to determine gas breakthrough pressures at ultimate limit state (high pressure range) and gas emission rates at serviceability limit state (low pressure range). Various degrees of saturation and thicknesses of unsaturated clay sample were considered. Moreover, numerical simulations were carried out using a coupled gas-water flow finite element program (CODE-BRIGHT) to better understand the experimental results by extending the clay thickness and varying the degree of saturation to a broader range that is typical at different climate conditions. The results of experimental study and numerical simulation reveal that as the degree of saturation and thickness of clay increase, the gas breakthrough pressure increases but the gas emission rate decreases significantly. Under a gas pressure of 10 kPa (the upper bound limit of typical landfill gas pressure), a 0.6m or thicker

  1. ELECTRIC POWER GENERATION USING A PHOSPHORIC ACID FUEL CELL ON A MUNICIPAL SOLID WASTE LANDFILL GAS STREAM

    EPA Science Inventory

    The report gives results of tests to verify the performance of a landfill gas pretreatment unit (GPU) and a phorsphoric acid fuel cell system. The complete system removes contaminants from landfill gas and produces electricity for on-site use or connection to an electric grid. Th...

  2. Greenhouse gas emissions from two-stage landfilling of municipal solid waste

    NASA Astrophysics Data System (ADS)

    Zhang, Yuanyuan; Yue, Dongbei; Nie, Yongfeng

    2012-08-01

    Simulations were conducted to investigate greenhouse gas emissions from aerobic pretreatment and subsequent landfilling. The flows in carbon balance, such as gas, leachate, and solid phases, were considered in the simulations. The total amount of CO2 eq. decreased as organic removal efficiency (ORE) increased. At ORE values of 0, 0.30, 0.41, and 0.54, the total amounts of CO2 eq. were 2614, 2326, 2075, and 1572 kg CO2 eq. per one ton dry matter, respectively; gas accounted for the main contribution to the total amount. The reduction in CO2 eq. from leachate was the primary positive contribution, accounting for 356%, 174%, and 100% of total reduction at ORE values of 0.30, 0.41, and 0.54, respectively. The CO2 eq. from energy consumption was the negative contribution to total reduction, but this contribution is considerably lower than that from gas. Aerobic pretreatment shortened the lag time of biogas production by 74.1-97.0%, and facilitated the transfer of organic carbon in solid waste from uncontrolled biogas and highly polluting leachate to aerobically generated CO2.

  3. Kentucky State Primer. A Primer on Developing Kentucky's Landfill Gas-to-Energy Potential

    NASA Astrophysics Data System (ADS)

    2000-05-01

    Throughout the country, the number of landfill gas-to-energy (LFGTE) projects is growing. Recovering methane gas at solid waste landfills provides significant environmental and economic benefits by eliminating methane emissions while capturing the emissions energy value. The methane captured from landfills can be transformed into a cost-effective fuel source for generating electricity and heat, firing boilers, or even powering vehicles. Permits, incentive programs, and policies for LFGTE project development vary greatly from state to state. To guide LFGTE project developers through the state permitting process and to help them to take advantage of state incentive programs, the U.S. Environmental Protection Agencys (EPAs) Landfill Methane Outreach Program (LMOP) has worked with state agencies to develop individual primers for states participating in the State Ally Program. By presenting the latest information on federal and state regulations and incentives affecting LFGTE projects in this primer, the LMOP and Kentucky state officials hope to facilitate development of many of the landfills listed in Table A. To develop this primer, the Commonwealth of Kentucky identified all the permits and funding programs that could apply to LFGTE projects developed in Kentucky. It should be noted, however, that the regulations, agencies, and policies described are subject to change. Changes are likely to occur whenever a state legislature meets, or when the federal government imposes new directions on state and local governments. LFGTE project developers should verify and continuously monitor the status of laws and rules that might affect their plans or the operations of their projects.

  4. Controlled Landfill Project in Yolo County, California for Environmental Benefits of Waste Stabilization and Minimization of Greenhouse Gas Emissions

    NASA Astrophysics Data System (ADS)

    Yazdani, R.; Augenstein, D.; Kieffer, J.; Cohen, K.

    2003-12-01

    The Department of Public Works of Yolo County, California, USA has been testing an advanced approach to landfill bioreactors, controlled (or "enhanced") landfilling, at its Yolo County Central Landfill site near Davis, CA, since 1994. Overall objectives have been the management of waste landfilling for: (1) rapid completion of total gas generation; (2) maximum, high-efficiency gas capture; (3) waste volume reduction; and (4) maximum greenhouse gas and carbon sequestration benefits. Methane generation is controlled and enhanced through carefully managed moisture additions, and by taking advantage of landfill temperature elevation. The generated landfill methane, an important greenhouse gas, is recovered with high efficiency through extraction from a porous recovery layer beneath a surface geomembrane cover. Instrumentation included a total of 56 moisture and 15 temperature sensors in the two cells, gas flow monitoring by positive displacement gas meters, and accurate quantification of liquid inputs and outputs. Gas composition, waste volume reduction, base hydrostatic head, and a range of environmental compliance parameters has been monitored since 1995. Partitioning gas tracer tests using the injection of two gases at dilute concentrations in the landfill have also been initiated to compute the fraction of pore space occupied by water between the points of tracer injection and tracer measurement. There has been rapid waste volume reduction in the enhanced cell that corresponds to the solids' reduction to gas. Monitoring is planned for the next several years, until stabilization parameters are determined complete. Encouraging performance is indicated by: (1) sensor data; (2) gas generation results; (3) data from landfill cores; and (4) decomposition-related indicators including rapid volume reduction. When data are synthesized, project results have attractive implications for new approaches to landfill management. Over seven-years, methane recoveries have averaged

  5. Effectiveness of compacted soil liner as a gas barrier layer in the landfill final cover system.

    PubMed

    Moon, Seheum; Nam, Kyoungphile; Kim, Jae Young; Hwan, Shim Kyu; Chung, Moonkyung

    2008-01-01

    A compacted soil liner (CSL) has been widely used as a single barrier layer or a part of composite barrier layer in the landfill final cover system to prevent water infiltration into solid wastes for its acceptable hydraulic permeability. This study was conducted to test whether the CSL was also effective in prohibiting landfill gas emissions. For this purpose, three different compaction methods (i.e., reduced, standard, and modified Proctor methods) were used to prepare the soil specimens, with nitrogen as gas, and with water and heptane as liquid permeants. Measured gas permeability ranged from 2.03 x 10(-10) to 4.96 x 10(-9) cm(2), which was a magnitude of two or three orders greater than hydraulic permeability (9.60 x 10(-13) to 1.05 x 10(-11) cm(2)). The difference between gas and hydraulic permeabilities can be explained by gas slippage, which makes gas more permeable, and by soil-water interaction, which impedes water flow and then makes water less permeable. This explanation was also supported by the result that a liquid permeability measured with heptane as a non-polar liquid was similar to the intrinsic gas permeability. The data demonstrate that hydraulic requirement for the CSL is not enough to control the gas emissions from a landfill. PMID:17964132

  6. Effectiveness of compacted soil liner as a gas barrier layer in the landfill final cover system.

    PubMed

    Moon, Seheum; Nam, Kyoungphile; Kim, Jae Young; Hwan, Shim Kyu; Chung, Moonkyung

    2008-01-01

    A compacted soil liner (CSL) has been widely used as a single barrier layer or a part of composite barrier layer in the landfill final cover system to prevent water infiltration into solid wastes for its acceptable hydraulic permeability. This study was conducted to test whether the CSL was also effective in prohibiting landfill gas emissions. For this purpose, three different compaction methods (i.e., reduced, standard, and modified Proctor methods) were used to prepare the soil specimens, with nitrogen as gas, and with water and heptane as liquid permeants. Measured gas permeability ranged from 2.03 x 10(-10) to 4.96 x 10(-9) cm(2), which was a magnitude of two or three orders greater than hydraulic permeability (9.60 x 10(-13) to 1.05 x 10(-11) cm(2)). The difference between gas and hydraulic permeabilities can be explained by gas slippage, which makes gas more permeable, and by soil-water interaction, which impedes water flow and then makes water less permeable. This explanation was also supported by the result that a liquid permeability measured with heptane as a non-polar liquid was similar to the intrinsic gas permeability. The data demonstrate that hydraulic requirement for the CSL is not enough to control the gas emissions from a landfill.

  7. LANDFILL GAS ENERGY UTILIZATION EXPERIENCE: DISCUSSION OF TECHNICAL AND NON-TECHNICAL ISSUES, SOLUTIONS, AND TRENDS

    EPA Science Inventory

    The report discusses technical and non-technical considerations associated with the development and operation of landfill gas to energy projects. Much of the report is based on interviews and site visits with the major developers and operators of the more than 110 projects in the...

  8. Impact of different plants on the gas profile of a landfill cover

    SciTech Connect

    Reichenauer, Thomas G.; Watzinger, Andrea; Riesing, Johann; Gerzabek, Martin H.

    2011-05-15

    Research highlights: > Plants influence gas profile and methane oxidation in landfill covers. > Plants regulate water content and increase the availability of oxygen for methane oxidation. > Plant species with deep roots like alfalfa showed more stimulation of methane oxidation than plants with shallow root systems like grasses. - Abstract: Methane is an important greenhouse gas emitted from landfill sites and old waste dumps. Biological methane oxidation in landfill covers can help to reduce methane emissions. To determine the influence of different plant covers on this oxidation in a compost layer, we conducted a lysimeter study. We compared the effect of four different plant covers (grass, alfalfa + grass, miscanthus and black poplar) and of bare soil on the concentration of methane, carbon dioxide and oxygen in lysimeters filled with compost. Plants were essential for a sustainable reduction in methane concentrations, whereas in bare soil, methane oxidation declined already after 6 weeks. Enhanced microbial activity - expected in lysimeters with plants that were exposed to landfill gas - was supported by the increased temperature of the gas in the substrate and the higher methane oxidation potential. At the end of the first experimental year and from mid-April of the second experimental year, the methane concentration was most strongly reduced in the lysimeters containing alfalfa + grass, followed by poplar, miscanthus and grass. The observed differences probably reflect the different root morphology of the investigated plants, which influences oxygen transport to deeper compost layers and regulates the water content.

  9. Analysis of Indirect Emissions Benefits of Wind, Landfill Gas, and Municipal Solid Waste Generation

    EPA Science Inventory

    Techniques are introduced to calculate the hourly indirect emissions benefits of three types of green power resources: wind energy, municipal solid waste (MSW) combustion, and landfill gas (LFG) combustion. These techniques are applied to each of the U.S. EPA's eGRID subregions i...

  10. DATABASE OF LANDFILL GAS TO ENERGY PROJECTS IN THE UNITED STATES

    EPA Science Inventory

    The paper discusses factors influencing the increase of landfill gas to energy (LFG-E) projects in the U.S. and presents recent statistics from a database,. There has been a dramatic increase in the number of LFG-E projects in the U.S., due to such factors as implementation of t...

  11. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS - PHASE I FINAL REPORT: CONCEPTUAL STUDY

    EPA Science Inventory

    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...

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

    NASA Astrophysics Data System (ADS)

    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.

  13. TESTING OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS: GROTON LANDFILL

    EPA Science Inventory

    The report summarizes the results of follow-on tests following a four-phase EPA program. The environmental impact of widespread use of this concept would be a significant reduction of global warming gas emissions (methane and carbon dioxide). The follow-on testing, conducted by N...

  14. Methane emissions from MBT landfills

    SciTech Connect

    Heyer, K.-U. Hupe, K.; Stegmann, R.

    2013-09-15

    Highlights: • Compilation of methane generation potential of mechanical biological treated (MBT) municipal solid waste. • Impacts and kinetics of landfill gas production of MBT landfills, approach with differentiated half-lives. • Methane oxidation in the waste itself and in soil covers. • Estimation of methane emissions from MBT landfills in Germany. - Abstract: Within the scope of an investigation for the German Federal Environment Agency (“Umweltbundesamt”), the basics for the estimation of the methane emissions from the landfilling of mechanically and biologically treated waste (MBT) were developed. For this purpose, topical research including monitoring results regarding the gas balance at MBT landfills was evaluated. For waste treated to the required German standards, a methane formation potential of approximately 18–24 m{sup 3} CH{sub 4}/t of total dry solids may be expected. Monitoring results from MBT landfills show that a three-phase model with differentiated half-lives describes the degradation kinetics in the best way. This is due to the fact that during the first years of disposal, the anaerobic degradation processes still proceed relatively intensively. In addition in the long term (decades), a residual gas production at a low level is still to be expected. Most of the soils used in recultivation layer systems at German landfills show a relatively high methane oxidation capacity up to 5 l CH{sub 4}/(m{sup 2} h). However, measurements at MBT disposal sites indicate that the majority of the landfill gas (in particular at non-covered areas), leaves the landfill body via preferred gas emission zones (hot spots) without significant methane oxidation. Therefore, rather low methane oxidation factors are recommended for open and temporarily covered MBT landfills. Higher methane oxidation rates can be achieved when the soil/recultivation layer is adequately designed and operated. Based on the elaborated default values, the First Order Decay (FOD

  15. Gas permeability of biochar-amended clay: potential alternative landfill final cover material.

    PubMed

    Wong, James Tsz Fung; Chen, Zhongkui; Ng, Charles Wang Wai; Wong, Ming Hung

    2016-04-01

    Compacted biochar-amended clay (BAC) has been proposed as an alternative landfill final cover material in this study. Biochar has long been proposed to promote crop growth, mitigate odor emission, and promote methane oxidation in field soils. However, previous studies showed that soil-gas permeability was increased upon biochar application, which will promote landfill gas emission. The objective of the present study is to investigate the possibility of using compacted BAC as an alternative material in landfill final cover by evaluating its gas permeability. BAC samples were prepared by mixing 425-μm-sieved peanut shell biochar with kaolin clay in different ratios (0, 5, 10, and 15 %, w/w) and compacting at different degrees of compactions (DOC) (80, 85, and 90 %) with an optimum water content of 35 %. The gas permeability of the BACs was measured by flexible wall gas permeameter and the microstructure of the BACs was analyzed by SEM with energy-dispersive x-ray spectroscopy (EDX). The results show that the effects of biochar content on BAC gas permeability is highly dependent on the DOC. At high DOC (90 %), the gas permeability of BAC decreases with increasing biochar content due to the combined effect of the clay aggregation and the inhibition of biochar in the gas flow. However, at low DOC (80 %), biochar incorporation has no effects on gas permeability because it no longer acts as a filling material to the retard gas flow. The results from the present study imply that compacted BAC can be used as an alternative final cover material with decreased gas permeability when compared with clay.

  16. Gas permeability of biochar-amended clay: potential alternative landfill final cover material.

    PubMed

    Wong, James Tsz Fung; Chen, Zhongkui; Ng, Charles Wang Wai; Wong, Ming Hung

    2016-04-01

    Compacted biochar-amended clay (BAC) has been proposed as an alternative landfill final cover material in this study. Biochar has long been proposed to promote crop growth, mitigate odor emission, and promote methane oxidation in field soils. However, previous studies showed that soil-gas permeability was increased upon biochar application, which will promote landfill gas emission. The objective of the present study is to investigate the possibility of using compacted BAC as an alternative material in landfill final cover by evaluating its gas permeability. BAC samples were prepared by mixing 425-μm-sieved peanut shell biochar with kaolin clay in different ratios (0, 5, 10, and 15 %, w/w) and compacting at different degrees of compactions (DOC) (80, 85, and 90 %) with an optimum water content of 35 %. The gas permeability of the BACs was measured by flexible wall gas permeameter and the microstructure of the BACs was analyzed by SEM with energy-dispersive x-ray spectroscopy (EDX). The results show that the effects of biochar content on BAC gas permeability is highly dependent on the DOC. At high DOC (90 %), the gas permeability of BAC decreases with increasing biochar content due to the combined effect of the clay aggregation and the inhibition of biochar in the gas flow. However, at low DOC (80 %), biochar incorporation has no effects on gas permeability because it no longer acts as a filling material to the retard gas flow. The results from the present study imply that compacted BAC can be used as an alternative final cover material with decreased gas permeability when compared with clay. PMID:26092359

  17. Sensitivity analysis of the waste composition and water content parameters on the biogas production models on solid waste landfills

    NASA Astrophysics Data System (ADS)

    Rodrigo-Ilarri, Javier; Segura-Sobrino, Francisco; Rodrigo-Clavero, Maria-Elena

    2014-05-01

    Landfills are commonly used as the final deposit of urban solid waste. Despite the waste is previously processed on a treatment plant, the final amount of organic matter which reaches the landfill is large however. The biodegradation of this organic matter forms a mixture of greenhouse gases (essentially Methane and Carbon-Dioxide as well as Ammonia and Hydrogen Sulfide). From the environmental point of view, solid waste landfills are therefore considered to be one of the main greenhouse gas sources. Different mathematical models are usually applied to predict the amount of biogas produced on real landfills. The waste chemical composition and the availability of water in the solid waste appear to be the main parameters of these models. Results obtained when performing a sensitivity analysis over the biogas production model parameters under real conditions are shown. The importance of a proper characterizacion of the waste as well as the necessity of improving the understanding of the behaviour and development of the water on the unsaturated mass of waste are emphasized.

  18. A CASE STUDY DEMONSTRATING GUIDANCE FOR EVALUATING LANDFILL GAS EMISSIONS FROM CLOSED OR ABANDONED FACILITIES--SOMERSWORTH, NEW HAMPSHIRE

    EPA Science Inventory

    The purpose of the activities described in this document is to provide a demonstration of the procedures and methodologies described within the "Guidance for Evaluating Landfill Gas Emissions from Closed or Abandoned Facilities" (Guidance). This demonstration provides an example ...

  19. Bringing new life to old landfills

    SciTech Connect

    Rabasca, L.

    1996-01-01

    On the West Coast, Waste Management, Inc. is bringing new life to old landfills. The Bradley Landfill in Sun Valley, CA, just outside of Los Angeles, is being transformed into a recycling park, while a few hundred miles north, in the San Francisco Bay Area, an old landfill is now home to a transfer station and recycling center. WMI began transforming the landfill in the early 1990s.The first change was to process wood and green waste rather than landfilling it. In 1993, WMI added a sorting facility, and in 1994, after the Jan. 17 Northridge earthquake, the company added a construction and demolition debris (C and D) facility. There also is a landfill gas collection facility on the site. In the future, WMI hopes to add the following facilities: composting, railhaul, alternative fuels production, tire processing, and soil remediation. WMI also hopes several companies that use recycled materials as feedstock will build their plants at the landfill.

  20. Evaluating effects of wind-induced pressure fluctuations on soil-atmosphere gas exchange at a landfill using stochastic modelling.

    PubMed

    Poulsen, Tjalfe G; Møldrup, Per

    2006-10-01

    The impact of wind turbulence-induced pressure fluctuations at the soil surface on landfill gas transport and emissions to the atmosphere at an old Danish landfill site was investigated using stochastic modelling combined with soil property and gas transport data measured at the site. The impacts of soil physical properties (including air permeability and volumetric water content) and wind-induced pressure fluctuation properties (amplitude and temporal correlation) on landfill gas emissions to the atmosphere were evaluated. Soil-air permeability and pressure fluctuation amplitude were found to be the most important parameters. Wind-induced gas emissions were further compared with gas emissions caused by diffusion and by long-term pressure variations (due to passing weather systems). Here diffusion and wind-induced gas transport were found to be equally important with wind-induced gas transport becoming the most important at lower soil-air contents.

  1. Characterization of trichloroethylene adsorption onto waste biocover soil in the presence of landfill gas.

    PubMed

    He, Ruo; Su, Yao; Kong, Jiaoyan

    2015-09-15

    Waste biocover soils (WBS) have been demonstrated to have great potential in mitigating trichloroethylene (TCE) emission from landfills, due to the relatively high TCE-degrading capacity. In this study, the characteristics of TCE adsorption on WBS in the presence of the major landfill gas components (i.e., CH4 and CO2) were investigated in soil microcosms. The adsorption isotherm of TCE onto WBS was fitted well with linear model within the TCE concentrations of 7000 ppmv. The adsorption capacity of TCE onto WBS was affected by temperature, soil moisture content and particle size, of which, temperature was the dominant factor. The adsorption capacity of TCE onto the experimental materials increased with the increasing organic matter content. A significantly positive correlation was observed between the adsorption capacity of TCE and the organic matter content of experimental materials that had relatively higher organic content (r = 0.988, P = 0.044). To better understand WBS application in practice, response surface methodology was developed to predict TCE adsorption capacity and emissions through WBS in different landfills in China. These results indicated that WBS had high adsorption capacity of TCE in LFG and temperature should be paid more attention to manipulate WBS to reduce TCE emissions from landfills.

  2. Characterization of trichloroethylene adsorption onto waste biocover soil in the presence of landfill gas.

    PubMed

    He, Ruo; Su, Yao; Kong, Jiaoyan

    2015-09-15

    Waste biocover soils (WBS) have been demonstrated to have great potential in mitigating trichloroethylene (TCE) emission from landfills, due to the relatively high TCE-degrading capacity. In this study, the characteristics of TCE adsorption on WBS in the presence of the major landfill gas components (i.e., CH4 and CO2) were investigated in soil microcosms. The adsorption isotherm of TCE onto WBS was fitted well with linear model within the TCE concentrations of 7000 ppmv. The adsorption capacity of TCE onto WBS was affected by temperature, soil moisture content and particle size, of which, temperature was the dominant factor. The adsorption capacity of TCE onto the experimental materials increased with the increasing organic matter content. A significantly positive correlation was observed between the adsorption capacity of TCE and the organic matter content of experimental materials that had relatively higher organic content (r = 0.988, P = 0.044). To better understand WBS application in practice, response surface methodology was developed to predict TCE adsorption capacity and emissions through WBS in different landfills in China. These results indicated that WBS had high adsorption capacity of TCE in LFG and temperature should be paid more attention to manipulate WBS to reduce TCE emissions from landfills. PMID:25909498

  3. Adsorption characteristics of siloxanes in landfill gas by the adsorption equilibrium test.

    PubMed

    Nam, Sangchul; Namkoong, Wan; Kang, Jeong-Hee; Park, Jin-Kyu; Lee, Namhoon

    2013-10-01

    Due to the increase in energy cost by constantly high oil prices and the obligation to reduce greenhouse effect gases, landfill gas is frequently used as an alternative energy source for producing heat and electricity. Most of landfill gas utility facilities, however, are experiencing problems controlling siloxanes from landfill gas as their catalytic oxidizers are becoming fouled by silicon dioxide dust. To evaluate adsorption characteristics of siloxanes, an adsorption equilibrium test was conducted and parameters in the Freundlich and Langmuir isotherms were analyzed. Coconut activated carbon (CA1), coal activated carbon (CA2), impregnated activated carbon (CA3), silicagel (NCA1), and activated alumina (NCA2) were used for the adsorption of the mixed siloxane which contained hexamethyldisiloxane (L2), octamethylcyclotetrasiloxane (D4), and decamethylcyclopentasiloxane (D5). L2 had higher removal efficiency in noncarbon adsorbents compared to carbon adsorbents. The application of Langmuir and Freundlich adsorption isotherm demonstrated that coconut based CA1 and CA3 provided higher adsorption capacity on L2. And CA2 and NCA1 provided higher adsorption capacity on D4 and D5. Based on the experimental results, L2, D4, and D5 were converted by adsorption and desorption in noncarbon adsorbents. Adsorption affinity of siloxane is considered to be affect by the pore size distribution of the adsorbents and by the molecular size of each siloxane.

  4. Adsorption characteristics of siloxanes in landfill gas by the adsorption equilibrium test.

    PubMed

    Nam, Sangchul; Namkoong, Wan; Kang, Jeong-Hee; Park, Jin-Kyu; Lee, Namhoon

    2013-10-01

    Due to the increase in energy cost by constantly high oil prices and the obligation to reduce greenhouse effect gases, landfill gas is frequently used as an alternative energy source for producing heat and electricity. Most of landfill gas utility facilities, however, are experiencing problems controlling siloxanes from landfill gas as their catalytic oxidizers are becoming fouled by silicon dioxide dust. To evaluate adsorption characteristics of siloxanes, an adsorption equilibrium test was conducted and parameters in the Freundlich and Langmuir isotherms were analyzed. Coconut activated carbon (CA1), coal activated carbon (CA2), impregnated activated carbon (CA3), silicagel (NCA1), and activated alumina (NCA2) were used for the adsorption of the mixed siloxane which contained hexamethyldisiloxane (L2), octamethylcyclotetrasiloxane (D4), and decamethylcyclopentasiloxane (D5). L2 had higher removal efficiency in noncarbon adsorbents compared to carbon adsorbents. The application of Langmuir and Freundlich adsorption isotherm demonstrated that coconut based CA1 and CA3 provided higher adsorption capacity on L2. And CA2 and NCA1 provided higher adsorption capacity on D4 and D5. Based on the experimental results, L2, D4, and D5 were converted by adsorption and desorption in noncarbon adsorbents. Adsorption affinity of siloxane is considered to be affect by the pore size distribution of the adsorbents and by the molecular size of each siloxane. PMID:23684695

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Gas Transport Parameters for Landfill Cover Soils: Effects of Soil Compaction and Water Blockages

    NASA Astrophysics Data System (ADS)

    Wickramarachchi, P. N.; Hamamoto, S.; Kawamoto, K.; Nawagamuwa, U.; Komatsu, T.; Moldrup, P.

    2009-12-01

    Recently, landfill sites have been emerging in greenhouse warming scenarios as a significant source of atmospheric CH4. landfill management strategies have mainly addressed the problem of preventing groundwater contamination and reduction of leachate generation. Being one of the largest source of anthropogenic CH4 emission , the final cover system should also be designed for minimizing the biogas migration into the atmosphere or the areas surrounding the landfill. Compared to the intensive research efforts on hydraulic performances of landfill final cover soil , there are few studies about gas transport characteristics of landfill cover soils. Therefore, the effects of soil physical properties such as bulk density (i.e., compaction level), soil particle size and water blockage effects on the gas exchange in t highly compacted final cover soil are largely unknown. 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 water blockage effects on ka and Dp for two landfill final cover soils were investigated. The disturbed soil samples were taken from landfill final covers in Japan and Sri Lanka. A compaction tests were performed for the soil samples with two different size fractions (< 35 mm and < 2.0 mm). In the compaction tests at field water content , the soil samples were repacked into soil cores (i.d. 15-cm, length 12-cm) at two different compaction levels (2700 kN/m2 and 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 (pF; pF equals to log(-ɛ) where ɛ is soil-water matric potential in cm H2O) of 1.5, 2.0, 3.0, 4.1, and with air-dried (pF 6.0) and oven-dried (pF 6.9) conditions. Results showed that measured Dp values

  7. Evaluation of a biologically active cover for mitigation of landfill gas emissions.

    PubMed

    Barlaz, M A; Green, R B; Chanton, J P; Goldsmith, C D; Hater, G R

    2004-09-15

    Landfills are the third largest source of anthropogenic CH4 in the United States, and there is potential for reduction in this source of greenhouse gases and other contaminants. The objective of this work was to contrast emissions of CH4 and non-methane organic compounds (NMOCs) from landfill cells covered with soil or a biologically active cover consisting of yard waste compost. On the basis of four field campaigns over 14 months, CH4 emissions from the biocover (BC) varied from -1.73 to 1.33 g m(-2) d(-1), with atmospheric uptake measured in 52% of tests. BC emissions did not increase when the gas collection system was turned off. Uptake of atmospheric CH4 was measured in 54% of tests on the soil cover (SC) when the gas collection was system active and 12% when the gas collection system was off. Many (26%) relatively high fluxes (>15 g m(-2) d(-1)) were measured from the SC as were some dramatic effects due to deactivation of the gas collection system. In tests with positive emissions, stable isotope measurements showed that the BC and SC were responsible for oxidation of 55% and 21% of the CH4 reaching the bottom of the respective cover. Seven of the highest 10 NMOC emissions were measured in the SC, and 17 of 21 fluxes for speciated organic compounds were higher in the SC. The relationship between CH4, NMOC, and individual organic compound emissions suggested a correlation between CH4 and trace organic oxidation. BCs can reduce landfill gas emissions in the absence of a gas collection system and can serve as a polishing step in the presence of an active system.

  8. Characterization of microalgae-bacteria consortium cultured in landfill leachate for carbon fixation and lipid production.

    PubMed

    Zhao, Xin; Zhou, Yan; Huang, Sheng; Qiu, Duanyang; Schideman, Lance; Chai, Xiaoli; Zhao, Youcai

    2014-03-01

    The characteristics of cultivating high-density microalgae-bacteria consortium with landfill leachate was tested in this study. Landfill leachate was collected from Laogang landfill operated for over 10 years in Shanghai, China. The maximum biomass concentration of 1.58g L(-1) and chlorophyll a level of 22mg L(-1) were obtained in 10% leachate spike ratio. Meanwhile, up to 90% of the total nitrogen in landfill leachate was removed in culture with 10% leachate spike ratio with a total nitrogen concentration of 221.6mg L(-1). The fluorescence peak of humic-like organic matters red shifted to longer wavelengths by the end of culture, indicating that microalgae-bacteria consortium was effective for treating landfill leachate contaminants. Furthermore, with the leachate spike ratio of 10%, the maximum lipid productivity and carbon fixation were 24.1 and 65.8mg L(-1)d(-1), respectively. Results of this research provide valuable information for optimizing microalgae culture in landfill leachate.

  9. BIOLEACH: Coupled modeling of leachate and biogas production on solid waste landfills

    NASA Astrophysics Data System (ADS)

    Rodrigo-Clavero, Maria-Elena; Rodrigo-Ilarri, Javier

    2015-04-01

    One of the most important factors to address when performing the environmental impact assessment of urban solid waste landfills is to evaluate the leachate production. Leachate management (collection and treatment) is also one of the most relevant economical aspects to take into account during the landfill life. Leachate is formed as a solution of biological and chemical components during operational and post-operational phases on urban solid waste landfills as a combination of different processes that involve water gains and looses inside the solid waste mass. Infiltration of external water coming from precipitation is the most important component on this water balance. However, anaerobic waste decomposition and biogas formation processes play also a role on the balance as water-consuming processes. The production of leachate one biogas is therefore a coupled process. Biogas production models usually consider optimal conditions of water content on the solid waste mass. However, real conditions during the operational phase of the landfill may greatly differ from these optimal conditions. In this work, the first results obtained to predict both the leachate and the biogas production as a single coupled phenomenon on real solid waste landfills are shown. The model is applied on a synthetic case considering typical climatological conditions of Mediterranean catchments.

  10. Passive and active soil gas sampling at the Mixed Waste Landfill, Technical Area III, Sandia National Laboratories/New Mexico

    SciTech Connect

    McVey, M.D.; Goering, T.J.; Peace, J.L.

    1996-02-01

    The Environmental Restoration Project at Sandia National Laboratories, New Mexico is tasked with assessing and remediating the Mixed Waste Landfill in Technical Area III. The Mixed Waste Landfill is a 2.6 acre, inactive radioactive and mixed waste disposal site. In 1993 and 1994, an extensive passive and active soil gas sampling program was undertaken to identify and quantify volatile organic compounds in the subsurface at the landfill. Passive soil gas surveys identified levels of PCE, TCE, 1,1, 1-TCA, toluene, 1,1,2-trichlorotrifluoroethane, dichloroethyne, and acetone above background. Verification by active soil gas sampling confirmed concentrations of PCE, TCE, 1,1,1-TCA, and 1,1,2-trichloro-1,2,2-trifluoroethane at depths of 10 and 30 feet below ground surface. In addition, dichlorodifluoroethane and trichlorofluoromethane were detected during active soil gas sampling. All of the volatile organic compounds detected during the active soil gas survey were present in the low ppb range.

  11. Estimating methane production rates in bogs and landfills by deuterium enrichment of pore water

    USGS Publications Warehouse

    Siegel, D.I.; Chanton, J.P.; Glaser, P.H.; Chasar, L.S.; Rosenberry, D.O.

    2001-01-01

    Raised bogs and municipal waste landfills harbor large populations of methanogens within their domed deposits of anoxic organic matter. Although the methane emissions from these sites have been estimated by various methods, limited data exist on the activity of the methanogens at depth. We therefore analyzed the stable isotopic signature of the pore waters in two raised bogs from northern Minnesota to identify depth intervals in the peat profile where methanogenic metabolism occurs. Methanogenesis enriched the deuterium (2H) content of the deep peat pore waters by as much as +11% (Vienna Standard Mean Sea Water), which compares to a much greater enrichment factor of +70% in leachate from New York City's Fresh Kills landfill. The bog pore waters were isotopically dated by tritium (3H) to be about 35 years old at 1.5 m depth, whereas the landfill leachate was estimated as ~ 17 years old from Darcy flow calculations. According to an isotopic mass balance the observed deuterium enrichment indicates that about 1.2 g of CH4m-3 d-1 were produced within the deeper peat, compared to about 2.8 g CH4 m-3 d-1 in the landfill. The values for methane production in the bog peat are substantially higher than the flux rates measured at the surface of the bogs or at the landfill, indicating that deeper methane production may be much higher than was previously assumed.

  12. Estimating methane production rates in bogs and landfills by deuterium enrichment of pore water

    NASA Astrophysics Data System (ADS)

    Siegel, D. I.; Chanton, J. R.; Glaser, P. H.; Chasar, L. S.; Rosenberry, D. O.

    2001-12-01

    Raised bogs and municipal waste landfills harbor large populations of methanogens within their domed deposits of anoxic organic matter. Although the methane emissions from these sites have been estimated by various methods, limited data exist on the activity of the methanogens at depth. We therefore analyzed the stable isotopic signature of the pore waters in two raised bogs from northern Minnesota to identify depth intervals in the peat profile where methanogenic metabolism occurs. Methanogenesis enriched the deuterium (2H) content of the deep peat pore waters by as much as +11‰ (Vienna Standard Mean Sea Water), which compares to a much greater enrichment factor of +70‰ in leachate from New York City's Fresh Kills landfill. The bog pore waters were isotopically dated by tritium (3H) to be about 35 years old at 1.5 m depth, whereas the landfill leachate was estimated as ˜17 years old from Darcy flow calculations. According to an isotopic mass balance the observed deuterium enrichment indicates that about 1.2 g of CH4 m-3 d-1 were produced within the deeper peat, compared to about 2.8 g CH4 m-3 d-1 in the landfill. The values for methane production in the bog peat are substantially higher than the flux rates measured at the surface of the bogs or at the landfill, indicating that deeper methane production may be much higher than was previously assumed.

  13. Adsorption characteristics of siloxanes in landfill gas by the adsorption equilibrium test

    SciTech Connect

    Nam, Sangchul; Namkoong, Wan; Kang, Jeong-Hee; Park, Jin-Kyu; Lee, Namhoon

    2013-10-15

    Highlights: • Equilibrium test was attempted to evaluate adsorption characteristics of siloxane. • L2 had higher removal efficiency in carbon compared to noncarbon adsorbents. • Total adsorption capacity of siloxane was 300 mg/g by coal activated carbon. • Adsorption characteristics rely on size of siloxane molecule and adsorbent pore. • Conversion of siloxane was caused by adsorption of noncarbon adsorbents. - Abstract: Due to the increase in energy cost by constantly high oil prices and the obligation to reduce greenhouse effect gases, landfill gas is frequently used as an alternative energy source for producing heat and electricity. Most of landfill gas utility facilities, however, are experiencing problems controlling siloxanes from landfill gas as their catalytic oxidizers are becoming fouled by silicon dioxide dust. To evaluate adsorption characteristics of siloxanes, an adsorption equilibrium test was conducted and parameters in the Freundlich and Langmuir isotherms were analyzed. Coconut activated carbon (CA1), coal activated carbon (CA2), impregnated activated carbon (CA3), silicagel (NCA1), and activated alumina (NCA2) were used for the adsorption of the mixed siloxane which contained hexamethyldisiloxane (L2), octamethylcyclotetrasiloxane (D4), and decamethylcyclopentasiloxane (D5). L2 had higher removal efficiency in noncarbon adsorbents compared to carbon adsorbents. The application of Langmuir and Freundlich adsorption isotherm demonstrated that coconut based CA1 and CA3 provided higher adsorption capacity on L2. And CA2 and NCA1 provided higher adsorption capacity on D4 and D5. Based on the experimental results, L2, D4, and D5 were converted by adsorption and desorption in noncarbon adsorbents. Adsorption affinity of siloxane is considered to be affect by the pore size distribution of the adsorbents and by the molecular size of each siloxane.

  14. Experimental and life cycle assessment analysis of gas emission from mechanically–biologically pretreated waste in a landfill with energy recovery

    SciTech Connect

    Di Maria, Francesco Sordi, Alessio; Micale, Caterina

    2013-11-15

    Highlights: • Bio-methane landfill emissions from different period (0, 4, 8, 16 weeks) MTB waste have been evaluated. • Electrical energy recoverable from landfill gas ranges from 11 to about 90 kW h/tonne. • Correlation between oxygen uptake, energy recovery and anaerobic gas production shows R{sup 2} ranging from 0.78 to 0.98. • LCA demonstrate that global impact related to gaseous emissions achieve minimum for 4 week of MBT. - Abstract: The global gaseous emissions produced by landfilling the Mechanically Sorted Organic Fraction (MSOF) with different weeks of Mechanical Biological Treatment (MBT) was evaluated for an existing waste management system. One MBT facility and a landfill with internal combustion engines fuelled by the landfill gas for electrical energy production operate in the waste management system considered. An experimental apparatus was used to simulate 0, 4, 8 and 16 weeks of aerobic stabilization and the consequent biogas potential (Nl/kg) of a large sample of MSOF withdrawn from the full-scale MBT. Stabilization achieved by the waste was evaluated by dynamic oxygen uptake and fermentation tests. Good correlation coefficients (R{sup 2}), ranging from 0.7668 to 0.9772, were found between oxygen uptake, fermentation and anaerobic test values. On the basis of the results of several anaerobic tests, the methane production rate k (year{sup −1}) was evaluated. k ranged from 0.436 to 0.308 year{sup −1} and the bio-methane potential from 37 to 12 N m{sup 3}/tonne, respectively, for the MSOF with 0 and 16 weeks of treatment. Energy recovery from landfill gas ranged from about 11 to 90 kW h per tonne of disposed MSOF depending on the different scenario investigated. Life cycle analysis showed that the scenario with 0 weeks of pre-treatment has the highest weighted global impact even if opposite results were obtained with respect to the single impact criteria. MSOF pre-treatment periods longer than 4 weeks showed rather negligible variation

  15. Passive landfill gas emission - Influence of atmospheric pressure and implications for the operation of methane-oxidising biofilters.

    PubMed

    Gebert, Julia; Groengroeft, Alexander

    2006-01-01

    A passively vented landfill site in Northern Germany was monitored for gas emission dynamics through high resolution measurements of landfill gas pressure, flow rate and composition as well as atmospheric pressure and temperature. Landfill gas emission could be directly related to atmospheric pressure changes on all scales as induced by the autooscillation of air, diurnal variations and the passage of pressure highs and lows. Gas flux reversed every 20 h on average, with 50% of emission phases lasting only 10h or less. During gas emission phases, methane loads fed to a connected methane oxidising biofiltration unit varied between near zero and 247 g CH4 h(-1)m(-3) filter material. Emission dynamics not only influenced the amount of methane fed to the biofilter but also the establishment of gas composition profiles within the biofilter, thus being of high relevance for biofilter operation. The duration of the gas emission phase emerged as most significant variable for the distribution of landfill gas components within the biofilter.

  16. Improved methodology to assess modification and completion of landfill gas management in the aftercare period

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Municipal solid waste landfills represent the dominant option for waste disposal in many parts of the world. While some countries have greatly reduced their reliance on landfills, there remain thousands of landfills that require aftercare. The development of cost-effective strategies for landfill af...

  17. Determination of personal care products and hormones in leachate and groundwater from Polish MSW landfills by ultrasound-assisted emulsification microextraction and GC-MS.

    PubMed

    Kapelewska, Justyna; Kotowska, Urszula; Wiśniewska, Katarzyna

    2016-01-01

    Determination of the endocrine disrupting compounds (EDCs) in leachate and groundwater samples from the landfill sites is very important because of the proven harmful effects of these compounds on human and animal organisms. A method combining ultrasound-assisted emulsification microextraction (USAEME) and gas chromatography-mass spectrometry (GC-MS) was developed for simultaneous determination of seven personal care products (PCPs): methylparaben (MP), ethylparaben (EP), propylparaben (PP), buthylparaben (BP), benzophenone (BPh), 3-(4-methylbenzylidene)camphor (4-MBC), N,N-diethyltoluamide (DEET), and two hormones: estrone (E1) and β-estradiol (E2) in landfill leachate and groundwater samples. The limit of detection (LOD)/limit of quantification (LOQ) values in landfill leachate and groundwater samples were in the range of 0.003-0.083/0.009-0.277 μg L(-1) and 0.001-0.015/0.002-0.049 μg L(-1), respectively. Quantitative recoveries and satisfactory precision were obtained. All studied compounds were found in the landfill leachates from Polish municipal solid waste (MSW) landfills; the concentrations were between 0.66 and 202.42 μg L(-1). The concentration of pollutants in groundwater samples was generally below 0.1 μg L(-1). PMID:26381788

  18. Determination of personal care products and hormones in leachate and groundwater from Polish MSW landfills by ultrasound-assisted emulsification microextraction and GC-MS.

    PubMed

    Kapelewska, Justyna; Kotowska, Urszula; Wiśniewska, Katarzyna

    2016-01-01

    Determination of the endocrine disrupting compounds (EDCs) in leachate and groundwater samples from the landfill sites is very important because of the proven harmful effects of these compounds on human and animal organisms. A method combining ultrasound-assisted emulsification microextraction (USAEME) and gas chromatography-mass spectrometry (GC-MS) was developed for simultaneous determination of seven personal care products (PCPs): methylparaben (MP), ethylparaben (EP), propylparaben (PP), buthylparaben (BP), benzophenone (BPh), 3-(4-methylbenzylidene)camphor (4-MBC), N,N-diethyltoluamide (DEET), and two hormones: estrone (E1) and β-estradiol (E2) in landfill leachate and groundwater samples. The limit of detection (LOD)/limit of quantification (LOQ) values in landfill leachate and groundwater samples were in the range of 0.003-0.083/0.009-0.277 μg L(-1) and 0.001-0.015/0.002-0.049 μg L(-1), respectively. Quantitative recoveries and satisfactory precision were obtained. All studied compounds were found in the landfill leachates from Polish municipal solid waste (MSW) landfills; the concentrations were between 0.66 and 202.42 μg L(-1). The concentration of pollutants in groundwater samples was generally below 0.1 μg L(-1).

  19. Removal of hydrogen sulfide gas and landfill leachate treatment using coal bottom ash.

    PubMed

    Lin, C Y; Hesu, P H; Yang, D H

    2001-06-01

    Coal bottom ashes produced from three thermal power plants were used in column and batch experiments to investigate the adsorption capacity of the coal ash. Hydrogen sulfide and leachates collected from three sanitary landfill sites were used as adsorbate gas and solutions, respectively. Experimental results showed that coal bottom ash could remove H2S from waste gas or reduce the concentrations of various pollutants in the leachate. Each gram of bottom ash could remove up to 10.5 mg of H2S. In treating the landfill leachate, increasing ash dosage increased the removal efficiency but decreased the adsorption amount per unit mass of ash. For these tested ashes, the removal efficiencies of chemical oxygen demand (COD), NH3-N, total Kjeldhal nitrogen (TKN), P, Fe3+, Mn2+, and Zn2+ were 36.4-50, 24.2-39.4, 27.0-31.1, 82.2-92.9, 93.8-96.5, 93.7-95.4, and 80.5-82.2%, respectively; the highest adsorption capacities for those parameters were 3.5-5.6, 0.22-0.63, 0.36-0.45, 0.027-0.034, 0.050-0.053, 0.029-0.032, and 0.006 mg/g of bottom ash, respectively. The adsorption of pollutants in the leachate conformed to Freundlich's adsorption model.

  20. Assessment of soil-gas contamination at the 17th Street landfill, Fort Gordon, Georgia, 2011

    USGS Publications Warehouse

    Falls, W. Fred; Caldwell, Andral W.; Guimaraes, Wladmir G.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2012-01-01

    Assessments of contaminants in soil gas were conducted in two study areas at Fort Gordon, Georgia, in July and August of 2011 to supplement environmental contaminant data for previous studies at the 17th Street landfill. The two study areas include northern and eastern parts of the 17th Street landfill and the adjacent wooded areas to the north and east of the landfill. These study areas were chosen because of their close proximity to the surface water in Wilkerson Lake and McCoys Creek. A total of 48 soil-gas samplers were deployed for the July 28 to August 3, 2011, assessment in the eastern study area. The assessment mostly identified detections of total petroleum hydrocarbons (TPH), and gasoline- and diesel-range compounds, but also identified the presence of chlorinated solvents in six samplers, chloroform in three samplers, 2-methyl naphthalene in one sampler, and trimethylbenzene in one sampler. The TPH masses exceeded 0.02 microgram (μg) in all 48 samplers and exceeded 0.9 μg in 24 samplers. Undecane, one of the three diesel-range compounds used to calculate the combined mass for diesel-range compounds, was detected in 17 samplers and is the second most commonly detected compound in the eastern study area, exceeded only by the number of TPH detections. Six samplers had detections of toluene, but other gasoline compounds were detected with toluene in three of the samplers, including detections of ethylbenzene, meta- and para-xylene, and octane. All detections of chlorinated organic compounds had soil-gas masses equal to or less than 0.08 μg, including three detections of trichloroethene, three detections of perchloroethene, three chloroform detections, one 1,4-dichlorobenzene detection, and one 1,1,2-trichloroethane detection. Three methylated compounds were detected in the eastern study area, but were detected at or below method detection levels. A total of 32 soil-gas samplers were deployed for the August 11–24, 2011, assessment in the northern study

  1. Assessment of soil-gas and groundwater contamination at the Gibson Road landfill, Fort Gordon, Georgia, 2011

    USGS Publications Warehouse

    Falls, W. Fred; Caldwell, Andral W.; Guimaraes, Wladmir G.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2012-01-01

    Soil-gas and groundwater assessments were conducted at the Gibson Road landfill in 201 to provide screening-level environmental contamination data to supplement the data collected during previous environmental studies at the landfill. Passive samplers were used in both assessments to detect volatile and semivolatile organic compounds and polycyclic aromatic hydrocarbons in soil gas and groundwater. A total of 56 passive samplers were deployed in the soil in late July and early August for the soil-gas assessment. Total petroleum hydrocarbons (TPH) were detected at masses greater than the method detection level of 0.02 microgram in all samplers and masses greater than 2.0 micrograms in 13 samplers. Three samplers located between the landfill and a nearby wetland had TPH masses greater than 20 micrograms. Diesel was detected in 28 of the 56 soil-gas samplers. Undecane, tridecane, and pentadecane were detected, but undecane was the most common diesel compound with 23 detections. Only five detections exceeded a combined diesel mass of 0.10 microgram, including the highest mass of 0.27 microgram near the wetland. Toluene was detected in only five passive samplers, including masses of 0.65 microgram near the wetland and 0.85 microgram on the southwestern side of the landfill. The only other gasoline-related compound detected was octane in two samplers. Naphthalene was detected in two samplers in the gully near the landfill and two samplers along the southwestern side of the landfill, but had masses less than or equal to 0.02 microgram. Six samplers located southeast of the landfill had detections of chlorinated compounds, including one perchloroethene detections (0.04 microgram) and five chloroform detections (0.05 to0.08 microgram). Passive samplers were deployed and recovered on August 8, 2011, in nine monitoring wells along the southwestern, southeastern and northeastern sides of the landfill and down gradient from the eastern corner of the landfill. Six of the nine

  2. Is biodegradability a desirable attribute for discarded solid waste? Perspectives from a national landfill greenhouse gas inventory model.

    PubMed

    Levis, James W; Barlaz, Morton A

    2011-07-01

    There is increasing interest in the use of biodegradable materials because they are believed to be "greener". In a landfill, these materials degrade anaerobically to form methane and carbon dioxide. The fraction of the methane that is collected can be utilized as an energy source and the fraction of the biogenic carbon that does not decompose is stored in the landfill. A landfill life-cycle model was developed to represent the behavior of MSW components and new materials disposed in a landfill representative of the U.S. average with respect to gas collection and utilization over a range of environmental conditions (i.e., arid, moderate wet, and bioreactor). The behavior of materials that biodegrade at relatively fast (food waste), medium (biodegradable polymer) and slow (newsprint and office paper) rates was studied. Poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) (PHBO) was selected as illustrative for an emerging biodegradable polymer. Global warming potentials (GWP) of 26, 720, -1000, 990, and 1300 kg CO(2)e wet Mg(-1) were estimated for MSW, food waste, newsprint, office paper, and PHBO, respectively in a national average landfill. In a state-of-the-art landfill with gas collection and electricity generation, GWP's of -250, 330, -1400, -96, and -420 kg CO(2)e wet Mg(-1) were estimated for MSW, food waste, newsprint, office paper and PHBO, respectively. Additional simulations showed that for a hypothetical material, a slower biodegradation rate and a lower extent of biodegradation improve the environmental performance of a material in a landfill representative of national average conditions.

  3. Is biodegradability a desirable attribute for discarded solid waste? Perspectives from a national landfill greenhouse gas inventory model.

    PubMed

    Levis, James W; Barlaz, Morton A

    2011-07-01

    There is increasing interest in the use of biodegradable materials because they are believed to be "greener". In a landfill, these materials degrade anaerobically to form methane and carbon dioxide. The fraction of the methane that is collected can be utilized as an energy source and the fraction of the biogenic carbon that does not decompose is stored in the landfill. A landfill life-cycle model was developed to represent the behavior of MSW components and new materials disposed in a landfill representative of the U.S. average with respect to gas collection and utilization over a range of environmental conditions (i.e., arid, moderate wet, and bioreactor). The behavior of materials that biodegrade at relatively fast (food waste), medium (biodegradable polymer) and slow (newsprint and office paper) rates was studied. Poly(3-hydroxybutyrate-co-3-hydroxyoctanoate) (PHBO) was selected as illustrative for an emerging biodegradable polymer. Global warming potentials (GWP) of 26, 720, -1000, 990, and 1300 kg CO(2)e wet Mg(-1) were estimated for MSW, food waste, newsprint, office paper, and PHBO, respectively in a national average landfill. In a state-of-the-art landfill with gas collection and electricity generation, GWP's of -250, 330, -1400, -96, and -420 kg CO(2)e wet Mg(-1) were estimated for MSW, food waste, newsprint, office paper and PHBO, respectively. Additional simulations showed that for a hypothetical material, a slower biodegradation rate and a lower extent of biodegradation improve the environmental performance of a material in a landfill representative of national average conditions. PMID:21615182

  4. Evaluation of aerated biofilter systems for microbial methane oxidation of poor landfill gas.

    PubMed

    Haubrichs, R; Widmann, R

    2006-01-01

    In the long-term, landfills are producing landfill gas (LFG) with low calorific values. Therefore, the utilization of LFG in combined heat and power plants (CHP) is limited to a certain period of time. A feasible method for LFG treatment is microbial CH(4) oxidation. Different materials were tested in actively aerated lab-scale bio-filter systems with a volume of 0.167 m(3). The required oxygen for the microbial CH(4) oxidation was provided through perforated probes, which distributed ambient air into the filter material. Three air input levels were installed along the height of the filter, each of them adjusted to a particular flow rate. During the tests, stable degradation rates of around 28 g/(m(3) h) in a fine-grained compost material were observed at a CH(4) inlet concentration of 30% over a period of 148 days. Compared with passive (not aerated) tests, the CH(4) oxidation rate increased by a factor of 5.5. Therefore, the enhancement of active aeration on the microbial CH(4) oxidation was confirmed. At a O(2)/CH(4) ratio of 2.5, nearly 100% of the CH(4) load was decomposed. By lowering the ratio from 2.5 to 2, the efficiency fell to values from 88% to 92%. By varying the distribution to the three air input levels, the CH(4) oxidation process was spread more evenly over the filter volume. PMID:16386886

  5. Evaluation of aerated biofilter systems for microbial methane oxidation of poor landfill gas.

    PubMed

    Haubrichs, R; Widmann, R

    2006-01-01

    In the long-term, landfills are producing landfill gas (LFG) with low calorific values. Therefore, the utilization of LFG in combined heat and power plants (CHP) is limited to a certain period of time. A feasible method for LFG treatment is microbial CH(4) oxidation. Different materials were tested in actively aerated lab-scale bio-filter systems with a volume of 0.167 m(3). The required oxygen for the microbial CH(4) oxidation was provided through perforated probes, which distributed ambient air into the filter material. Three air input levels were installed along the height of the filter, each of them adjusted to a particular flow rate. During the tests, stable degradation rates of around 28 g/(m(3) h) in a fine-grained compost material were observed at a CH(4) inlet concentration of 30% over a period of 148 days. Compared with passive (not aerated) tests, the CH(4) oxidation rate increased by a factor of 5.5. Therefore, the enhancement of active aeration on the microbial CH(4) oxidation was confirmed. At a O(2)/CH(4) ratio of 2.5, nearly 100% of the CH(4) load was decomposed. By lowering the ratio from 2.5 to 2, the efficiency fell to values from 88% to 92%. By varying the distribution to the three air input levels, the CH(4) oxidation process was spread more evenly over the filter volume.

  6. Assessing the performance of gas collection systems in select Chinese landfills according to the LandGEM model: drawbacks and potential direction.

    PubMed

    Sun, Yue; Yue, Dongbei; Li, Rundong; Yang, Ting; Liu, Shiliang

    2015-01-01

    In China, municipal solid waste (MSW) is primarily treated by landfilling. Landfill gas (LFG) collection effectively reduces methane emission from MSW landfills. An accurate system of LFG collection is important in landfill planning, design, and operation. However, China has not developed such systems. In this study, the efficiency of methane collection is calculated in three Chinese landfills with different collection systems (A: vertical wells for MSW before 2010; combined horizontal trenches and under-membrane pipes for MSW from 2011 onwards; B: combined horizontal trenches and vertical wells; C: vertical wells only). This efficiency was computed by dividing the quantity of methane obtained from landfill operation records by the quantity estimated based on the LandGEM model. Results show that the collection efficiencies of landfills with vertical wells and/or horizontal pipes ranged from 8.3% to 27.9%, whereas those of a system equipped with geomembrane reached 65.3%. The poor performance of the landfills was attributed to the open burning of early-stage LFG, LFG release from cracks in high-density polyethylene covers, and high levels of leachate within a landfill site. Therefore, this study proposes an integrated LFG collection system that can remove leachate and collect gas from landfills that accept waste with high moisture content. PMID:26510610

  7. Gas production apparatus

    DOEpatents

    Winsche, Warren E.; Miles, Francis T.; Powell, James R.

    1976-01-01

    This invention relates generally to the production of gases, and more particularly to the production of tritium gas in a reliable long operating lifetime systems that employs solid lithium to overcome the heretofore known problems of material compatibility and corrosion, etc., with liquid metals. The solid lithium is irradiated by neutrons inside low activity means containing a positive (+) pressure gas stream for removing and separating the tritium from the solid lithium, and these means are contained in a low activity shell containing a thermal insulator and a neutron moderator.

  8. Experimental and life cycle assessment analysis of gas emission from mechanically-biologically pretreated waste in a landfill with energy recovery.

    PubMed

    Di Maria, Francesco; Sordi, Alessio; Micale, Caterina

    2013-11-01

    The global gaseous emissions produced by landfilling the Mechanically Sorted Organic Fraction (MSOF) with different weeks of Mechanical Biological Treatment (MBT) was evaluated for an existing waste management system. One MBT facility and a landfill with internal combustion engines fuelled by the landfill gas for electrical energy production operate in the waste management system considered. An experimental apparatus was used to simulate 0, 4, 8 and 16weeks of aerobic stabilization and the consequent biogas potential (Nl/kg) of a large sample of MSOF withdrawn from the full-scale MBT. Stabilization achieved by the waste was evaluated by dynamic oxygen uptake and fermentation tests. Good correlation coefficients (R(2)), ranging from 0.7668 to 0.9772, were found between oxygen uptake, fermentation and anaerobic test values. On the basis of the results of several anaerobic tests, the methane production rate k (year(-1)) was evaluated. k ranged from 0.436 to 0.308year(-1) and the bio-methane potential from 37 to 12Nm(3)/tonne, respectively, for the MSOF with 0 and 16weeks of treatment. Energy recovery from landfill gas ranged from about 11 to 90kWh per tonne of disposed MSOF depending on the different scenario investigated. Life cycle analysis showed that the scenario with 0weeks of pre-treatment has the highest weighted global impact even if opposite results were obtained with respect to the single impact criteria. MSOF pre-treatment periods longer than 4weeks showed rather negligible variation in the global impact of system emissions. PMID:23910244

  9. A CASE STUDY DEMONSTRATING GUIDANCE FOR EVALUATING LANDFILL GAS EMISSIONS FROM CLOSED OR ABANDONED FACILITIES--SOUTH KINGSTOWN, RHODE ISLAND

    EPA Science Inventory

    The report describes a case study that applies EPA/600/R-05/123a, the guidance for conducting air pathway analyses of landfill gas emissions that are of interest to superfund remedial project managers, on-scene coordinators, facility owners, and potentially responsible parties. T...

  10. In-Situ Quantification of Methanotrophic Activity in a Landfill Cover Soil Using Gas Push-Pull Tests

    NASA Astrophysics Data System (ADS)

    Gomez, K. E.; Gonzalez-Gil, G.; Schroth, M. H.; Zeyer, J.

    2007-12-01

    Landfills are both a major anthropogenic source and a sink for the greenhouse gas CH4. Methanogenic bacteria produce CH4 during the anaerobic digestion of landfill waste, whereas, methanotrophic bacteria consume CH4 as it is transported through a landfill cover soil. Methanotrophs are thought to be ubiquitous in soils, but typically exist in large numbers at oxic/anoxic interfaces, close to anaerobic methane sources but exposed to oxygen required for metabolism. Accurate in-situ quantification of the sink strength of methanotrophs in landfill cover soils is needed for global carbon balances and for local emissions mitigation strategies. We measured in-situ CH4 concentrations at 30, 60, and 100 cm depth at 18 evenly spaced locations across a landfill cover soil. Furthermore, we performed Gas Push-Pull Tests (GPPTs) to estimate in-situ rates of methanotrophic activity in the cover soil. The GPPT is a gas-tracer test in which a gas mixture containing CH4, O2, and non-reactive tracer gases is injected (pushed) into the soil followed by extraction (pull) from the same location. Quantification of CH4 oxidation rates is based upon comparison of the breakthrough curves of CH4 and tracer gases. We present the results of a series of GPPTs conducted at two locations in the cover soil to assess the feasibility and reproducibility of this technique to quantify methanotrophic activity. Additional GPPTs were performed with a methanotrophic inhibitor in the injection gas mixture to confirm the appropriate choice of tracers to quantify CH4 oxidation. Estimated CH4 oxidation rate constants indicate that the cover soil contains a highly active methanotrophic community.

  11. MATHEMATICAL MODEL FOR METHANE PRODUCTION FROM LANDFILL BIOREACTOR - A DISCUSSION PAPER HTTP://OIPS.AIP.ORG/EEO/

    EPA Science Inventory

    This discussion explains the experimental results of a landfill bioreactor (LFBR) from a microbiological perspective and provides a feasible strategy to evaluate methane production performance, since suitable models are complicated and not sufficiently reliable for anaerobic-syst...

  12. The effects of leachate recirculation with supplemental water addition on methane production and waste decomposition in a simulated tropical landfill.

    PubMed

    Sanphoti, N; Towprayoon, S; Chaiprasert, P; Nopharatana, A

    2006-10-01

    In order to increase methane production efficiency, leachate recirculation is applied in landfills to increase moisture content and circulate organic matter back into the landfill cell. In the case of tropical landfills, where high temperature and evaporation occurs, leachate recirculation may not be enough to maintain the moisture content, therefore supplemental water addition into the cell is an option that could help stabilize moisture levels as well as stimulate biological activity. The objectives of this study were to determine the effects of leachate recirculation and supplemental water addition on municipal solid waste decomposition and methane production in three anaerobic digestion reactors. Anaerobic digestion with leachate recirculation and supplemental water addition showed the highest performance in terms of cumulative methane production and the stabilization period time required. It produced an accumulated methane production of 54.87 l/kg dry weight of MSW at an average rate of 0.58 l/kg dry weight/d and reached the stabilization phase on day 180. The leachate recirculation reactor provided 17.04 l/kg dry weight at a rate of 0.14l/kg dry weight/d and reached the stabilization phase on day 290. The control reactor provided 9.02 l/kg dry weight at a rate of 0.10 l/kg dry weight/d, and reached the stabilization phase on day 270. Increasing the organic loading rate (OLR) after the waste had reached the stabilization phase made it possible to increase the methane content of the gas, the methane production rate, and the COD removal. Comparison of the reactors' efficiencies at maximum OLR (5 kgCOD/m(3)/d) in terms of the methane production rate showed that the reactor using leachate recirculation with supplemental water addition still gave the highest performance (1.56 l/kg dry weight/d), whereas the leachate recirculation reactor and the control reactor provided 0.69 l/kg dry weight/d and 0.43 l/kg dry weight/d, respectively. However, when considering

  13. Qualitative nontarget analysis of landfill leachate using gas chromatography time-of-flight mass spectrometry.

    PubMed

    Jernberg, Joonas; Pellinen, Jukka; Rantalainen, Anna-Lea

    2013-01-15

    Nontarget analysis means that a sample is analysed without preselection of the studied analytes. While target analysis attempts to determine whether certain selected compounds are present in the sample, nontarget analysis is performed to explore what unknown compounds can be found. We developed a nontarget method using a landfill leachate sample as a complex test sample. The method was based on the use of a gas chromatograph-time-of-flight mass spectrometer (GC-TOF-MS) for final analysis and a deconvolution computer application for data processing. This nontarget analysis method was tested and validated by applying it to a landfill leachate sample spiked with 11 organic pollutants that were treated as unknowns. Sensitivity was found to be the most critical parameter affecting the success of nontarget analysis. The limit of identification (LOI) was 2500 ng L(-1) for four of the 11 compounds, 500 ng L(-1) for three compounds and 100 ng L(-1) for one compound. Three compounds were not detected in any of the spiked samples. A six-stage identification process was developed based on the spiking experiments. The process was based on the forward fit value of the library hit, the number of deconvoluted ions and the accurate mass scoring of the measured ions. The process was applied to an unspiked leachate water sample. Altogether, 44 compounds were tentatively identified in the sample. Elemental compositions of 36 components were additionally determined for which an unequivocal compound identification could not be given. Nontarget analysis with GC-TOF-MS is a promising method for the qualitative analysis of complex water samples. However, we conclude that the computer application for nontarget analysis needs improvement to decrease the amount of manual work needed in the identification process.

  14. Consolidated, multimedia environmental review and licensing of a landfill gas combustion/electrical generation system in Maryland

    SciTech Connect

    Goldstein, D.R.; Brown, D.H.; Ross, J.B.; Mountain, P.D.

    1999-07-01

    To build a power plant or transmission line in the State of Maryland, a company must obtain a Certificate of Public Convenience and Necessity (CPCN) from the Maryland Public Service Commission (PSC). As part of this licensing process, applicants must address a full range of environmental, engineering, socioeconomic, planning, need, and cost issues. The CPCN constitutes permission to construct and operate the facility, and includes issuance of the required air quality and water appropriations permits. The Maryland Power Plant Research Program (PPRP) serves as the lead agency for the consolidated review of CPCN projects. A recent project in Maryland involved the beneficial use of collected landfill gas from a closed municipal solid waste landfill for the generation of up to 4 Megawatts (MW) of electricity. This electrical generation will be continuously fed into the existing transmission system under a power purchase agreement with the local power company. The project is unique is several aspects: the use of former Rolls Royce aircraft engines fitted with generator sets to produce electricity; the beneficial reuse of landfill gas which is currently being flared at the landfill; and the collaborative environmental review that was conducted for this project that resulted in a streamlined licensing approach. This paper will include: a description of the landfill gas combustion/electrical generation system; an explanation of the review process conducted for the project including New Source Review, ambient air impacts assessed through air dispersion modeling, noise generation impacts, and ecological impacts; background on power plant licensing in Maryland; and a discussion of how the collaborative approach led by PPRP proved to be proactive and environmentally beneficial.

  15. [Dispersion and analysis of odor pollution in landfill area under the enclosed operation condition].

    PubMed

    Lu, Peng; Wu, Shi-Xing; Dai, Zhi-Feng; Zhang, Xiao-Hui; Su, Zhao-Hui; Zhou, Xiao-Fei; Dai, Zhan-Guo; Lu, Xu-Fei; Zheng, Bin; Shen, Kai; Wei, Pan-Ming

    2013-03-01

    Odor pollution of landfill site is a serious problem accompanied with the urbanization process that influences city life. Generally, odor emission points in landfill boundary are detected by experience, but the pollution intensity, distribution and variation in the scope of landfill boundary are difficulty to describe. In this research, odor emission points were disclosed with equal odor concentration curves that were delineated using electric nose and GPS instrument. The leakage of landfill gas and exhaust emission from biogas incineration torch was the main cause of the odor pollution in landfill area. Gas production evaluation suggested that the improvement of landfill gas consumption is the key point to control the odor pollution at the landfill site.

  16. Enhanced Carbon Dioxide Capture from Landfill Gas Using Bifunctionalized Benzimidazole-Linked Polymers.

    PubMed

    Islamoglu, Timur; Behera, Swayamprabha; Kahveci, Zafer; Tessema, Tsemre-Dingel; Jena, Puru; El-Kaderi, Hani M

    2016-06-15

    Tuning the binding affinity of small gases and their selective uptake by porous adsorbents are vital for effective CO2 removal from gas mixtures for environmental protection and fuel upgrading. In this study, an amine-functionalized benzimidazole-linked polymer (BILP-6-NH2) was synthesized by a combination of pre- and postsynthetic modification techniques in two steps. Presynthetic incorporation of nitro groups resulted in stoichiometric functionalization (1 nitro/phenyl) in addition to noninvasive functionalization, where more than 80% of the surface area maintained compared to BILP-6. Experimental studies presented enhanced CO2 uptake and CO2/CH4 selectivity in BILP-6-NH2 compared to BILP-6, which are governed by the synergetic effect of benzimidazole and amine moieties. DFT calculations were used to understand the interaction modes of CO2 with BILP-6-NH2 and confirmed the efficacy of amine groups. Encouraged by the enhanced uptake and selectivity in BILP-6-NH2, we have evaluated its performance in landfill gas separation under vacuum swing adsorption (VSA) settings, which resulted in very promising working capacity and sorbent selection parameters outperforming most of the best solid adsorbent in the literature. PMID:27228220

  17. Landfill Gas Conversion to LNG and LCO{sub 2}. Phase II Final Report for January 25, 1999 - April 30, 2000

    SciTech Connect

    Brown, W. R.; Cook, W. J.; Siwajek, L. A.

    2000-10-20

    This report summarizes work on the development of a process to produce LNG (liquefied methane) for heavy vehicle use from landfill gas (LFG) using Acrion's CO{sub 2} wash process for contaminant removal and CO{sub 2} recovery.

  18. Integrated Combined Heat and Power/Advanced Reciprocating Internal Combustion Engine System for Landfill Gas to Power Applications

    SciTech Connect

    2009-02-01

    Gas Technology Institute will collaborate with Integrated CHP Systems Corporation, West Virginia University, Vronay Engineering Services, KAR Engineering Associates, Pioneer Air Systems, and Energy Concepts Company to recover waste heat from reciprocating engines. The project will integrate waste heat recovery along with gas clean-up technology system improvements. This will address fuel quality issues that have hampered expanded use of opportunity fuels such as landfill gas, digester biogas, and coal mine methane. This will enable increased application of CHP using renewable and domestically derived opportunity fuels.

  19. Natural gas production from Arctic gas hydrates

    SciTech Connect

    Collett, T.S. )

    1993-01-01

    The natural gas hydrates of the Messoyakha field in the West Siberian basin of Russia and those of the Prudhoe Bay-Kuparuk River area on the North Slope of Alaska occur within a similar series of interbedded Cretaceous and Tertiary sandstone and siltstone reservoirs. Geochemical analyses of gaseous well-cuttings and production gases suggest that these two hydrate accumulations contain a mixture of thermogenic methane migrated from a deep source and shallow, microbial methane that was either directly converted to gas hydrate or was first concentrated in existing traps and later converted to gas hydrate. Studies of well logs and seismic data have documented a large free-gas accumulation trapped stratigraphically downdip of the gas hydrates in the Prudhoe Bay-Kuparuk River area. The presence of a gas-hydrate/free-gas contact in the Prudhoe Bay-Kuparuk River area is analogous to that in the Messoyakha gas-hydrate/free-gas accumulation, from which approximately 5.17x10[sup 9] cubic meters (183 billion cubic feet) of gas have been produced from the hydrates alone. The apparent geologic similarities between these two accumulations suggest that the gas-hydrated-depressurization production method used in the Messoyakha field may have direct application in northern Alaska. 30 refs., 15 figs., 3 tabs.

  20. Degradability of Chlorinated Solvents in Landfill Environment

    NASA Astrophysics Data System (ADS)

    Wang, J. Y.; Litman, M.

    2002-12-01

    The use of landfills as an in situ remediation system represents a cost-effective alternative for groundwater remediation in the source area. This research was conducted to investigate the intrinsic bioattenuation capacity of the landfill ecosystem for chlorinated aliphatic hydrocarbons (CAHs). This research, using excavated refuse samples, studied how the reductive dechlorination of CAHs is linked to the decomposition of solid waste in landfills. Most research effort in groundwater remediation has focused on the contaminant plumes beneath and downgradient from landfills, while the source area remediation has received increasing attention. Bioreactor landfill and leachate recirculation projects have been planned and implemented by the USEPA and some states. However, the use of bioreactor landfill has primarily been considered only to expedite refuse decomposition. This research provides an understanding of the biological fate of CAHs in landfills, an understanding that can lead to the bioreactor landfill system designed to promote the degradation of pollutants right at the source. The research was conducted in two complementary systems: simulated landfill bioreactors and batch degradation experiment in serum bottles. Refuse samples were excavated from a municipal solid waste landfill located in Wayland, Massachusetts, USA. Bioreactors were designed and operated to facilitate refuse decomposition under landfilling conditions. For each reactor, leachate was collected and recirculated back to the reactor and gas was collected into a gas bag and the methane production rate was monitored. Target CAHs, tetrachloroethene (PCE) and trichloroethene (TCE), were added to selected reactors and maintained at about 20 uM each in leachate. The design is to study the effect of long-term exposure of refuse microorganisms to CAHs on the degradation potential of these chemicals in landfills. Changes of biochemical conditions in bioreactors, including leachate pH, leachate COD, and

  1. Influence of mechanical-biological waste pre-treatment methods on the gas formation in landfills

    SciTech Connect

    Bockreis, A. . E-mail: a.bockreis@iwar.tu-darmstadt.de; Steinberg, I.

    2005-07-01

    In order to minimise emissions and environmental impacts, only pre-treated waste should be disposed of. For the last six years, a series of continuous experiments has been conducted at the Institute WAR, TU Darmstadt, in order to determine the emissions from pre-treated waste. Different kinds of pre-treated waste were incubated in several reactors and various data, including production and composition of the gas and the leachate, were collected. In this paper, the interim results of gas production and the gas composition from different types of waste after a running time of six years are presented and discussed.

  2. Air-substrate mercury exchange associated with landfill disposal of coal combustion products.

    PubMed

    Xin, Mei; Gustin, Mae S; Ladwig, Kenneth; Pflughoeft-Hassett, Debra F

    2006-08-01

    Previous laboratory studies have shown that lignite-derived fly ash emitted mercury (Hg) to the atmosphere, whereas bituminous- and subbituminous-derived fly ash samples adsorbed Hg from the air. In addition, wet flue gas desulfurization (FGD) materials were found to have higher Hg emission rates than fly ash. This study investigated in situ Hg emissions at a blended bituminous-subbituminous ash landfill in the Great Lakes area and a lignite-derived ash and FGD solids landfill in the Midwestern United States using a dynamic field chamber. Fly ash and saturated FGD materials emitted Hg to atmosphere at low rates (-0.1 to 1.2 ng/ m2hr), whereas FGD material mixed with fly ash and pyrite exhibited higher emission rates (approximately 10 ng/m2hr) but were still comparable with natural background soils (-0.3 to 13 ng/ m2hr). Air temperature, solar radiation, and relative humidity were important factors correlated with measured Hg fluxes. Field study results were not consistent with corresponding laboratory observations in that fluxes measured in the latter were higher and more variable. This is hypothesized to be partially an artifact of the flux measurement methods.

  3. Report: management problems of solid waste landfills in Kuwait.

    PubMed

    Al-Yaqout, Anwar F; Hamoda, Mohamed F

    2002-08-01

    This paper evaluates current operational practices in municipal solid waste landfills in Kuwait to provide existing knowledge on uncontrolled landfilling and associated problems of solid waste disposal in developing countries. The current landfilling practices are safe neither for humans nor for the environment. The landfill sites receive all kinds of wastes such as food wastes, oil products, debris, dead animals, agricultural wastes, chemical wastes, wastewater and sewage sludge. The wastes are dumped, spread and compacted in an uncontrolled manner and cover material is not applied regularly. Dust created within the landfill site and gas emissions cause a public nuisance. The characteristics of leachate formed indicate high organic content and presence of heavy metals, salts and nutrients. There are no provisions for leachate or landfill gas collection at the landfill sites. Recommendations for adjustment in landfill operation have been made in recognition of the transition period that is experienced in proceeding from the past and present to the future management of landfills in Kuwait to safeguard the public health and protect the environment.

  4. A fully coupled model for water-gas-heat reactive transport with methane oxidation in landfill covers.

    PubMed

    Ng, C W W; Feng, S; Liu, H W

    2015-03-01

    Methane oxidation in landfill covers is a complex process involving water, gas and heat transfer as well as microbial oxidation. The coupled phenomena of microbial oxidation, water, gas, and heat transfer are not fully understood. In this study, a new model is developed that incorporates water-gas-heat coupled reactive transport in unsaturated soil with methane oxidation. Effects of microbial oxidation-generated water and heat are included. The model is calibrated using published data from a laboratory soil column test. Moreover, a series of parametric studies are carried out to investigate the influence of microbial oxidation-generated water and heat, initial water content on methane oxidation efficiency. Computed and measured results of gas concentration and methane oxidation rate are consistent. It is found that the coupling effects between water-gas-heat transfer and methane oxidation are significant. Ignoring microbial oxidation-generated water and heat can result in a significant difference in methane oxidation efficiency by 100%.

  5. A fully coupled model for water-gas-heat reactive transport with methane oxidation in landfill covers.

    PubMed

    Ng, C W W; Feng, S; Liu, H W

    2015-03-01

    Methane oxidation in landfill covers is a complex process involving water, gas and heat transfer as well as microbial oxidation. The coupled phenomena of microbial oxidation, water, gas, and heat transfer are not fully understood. In this study, a new model is developed that incorporates water-gas-heat coupled reactive transport in unsaturated soil with methane oxidation. Effects of microbial oxidation-generated water and heat are included. The model is calibrated using published data from a laboratory soil column test. Moreover, a series of parametric studies are carried out to investigate the influence of microbial oxidation-generated water and heat, initial water content on methane oxidation efficiency. Computed and measured results of gas concentration and methane oxidation rate are consistent. It is found that the coupling effects between water-gas-heat transfer and methane oxidation are significant. Ignoring microbial oxidation-generated water and heat can result in a significant difference in methane oxidation efficiency by 100%. PMID:25489976

  6. Solar photocatalytic treatment of landfill leachate using a solid mineral by-product as a catalyst.

    PubMed

    Poblete, Rodrigo; Prieto-Rodríguez, Lucia; Oller, Isabel; Maldonado, Manuel I; Malato, Sixto; Otal, Emilia; Vilches, Luis F; Fernández-Pereira, Constantino

    2012-08-01

    The treatment of municipal solid waste landfill leachate in a pilot plant made up of solar compound parabolic collectors, using a solid industrial titanium by-product (WTiO(2)) containing TiO(2) and Fe(III) as a photocatalyst, was investigated. In the study evidence was found showing that the degradation performed with WTiO(2) was mainly due to the Fe provided by this by-product, instead of TiO(2). However, although TiO(2) had very little effect by itself, a synergistic effect was observed between Fe and TiO(2). The application of WTiO(2), which produced coupled photo-Fenton and heterogeneous catalysis reactions, achieved a surprisingly high depuration level (86% of COD removal), higher than that reached by photo-Fenton using commercial FeSO(4) (43%) in the same conditions. After the oxidation process the biodegradability and toxicity of the landfill leachate were studied. The results showed that the leachate biodegradability was substantially increased, at least in the first stages of the process, and again that WTiO(2) was more efficient than FeSO(4) in terms of increasing biodegradability.

  7. Decomposition and carbon storage of selected paper products in laboratory-scale landfills.

    PubMed

    Wang, Xiaoming; De la Cruz, Florentino B; Ximenes, Fabiano; Barlaz, Morton A

    2015-11-01

    The objective of this study was to measure the anaerobic biodegradation of different types of paper products in laboratory-scale landfill reactors. The study included (a) measurement of the loss of cellulose, hemicellulose, organic carbon, and (b) measurement of the methane yields for each paper product. The test materials included two samples each of newsprint (NP), copy paper (CP), and magazine paper (MG), and one sample of diaper (DP). The methane yields, carbon storage factors and the extent of cellulose and hemicellulose decomposition all consistently show that papers made from mechanical pulps (e.g., NPs) are less degradable than those made from chemical pulps where essentially all lignin was chemically removed (e.g., CPs). The diaper, which is not only made from chemical pulp but also contains some gel and plastic, exhibited limited biodegradability. The extent of biogenic carbon conversion varied from 21 to 96% among papers, which contrasts with the uniform assumption of 50% by the Intergovernmental Panel on Climate Change (IPCC) for all degradable materials discarded in landfills. Biochemical methane potential tests also showed that the solids to liquid ratio used in the test can influence the results. PMID:26057726

  8. Decomposition and carbon storage of selected paper products in laboratory-scale landfills.

    PubMed

    Wang, Xiaoming; De la Cruz, Florentino B; Ximenes, Fabiano; Barlaz, Morton A

    2015-11-01

    The objective of this study was to measure the anaerobic biodegradation of different types of paper products in laboratory-scale landfill reactors. The study included (a) measurement of the loss of cellulose, hemicellulose, organic carbon, and (b) measurement of the methane yields for each paper product. The test materials included two samples each of newsprint (NP), copy paper (CP), and magazine paper (MG), and one sample of diaper (DP). The methane yields, carbon storage factors and the extent of cellulose and hemicellulose decomposition all consistently show that papers made from mechanical pulps (e.g., NPs) are less degradable than those made from chemical pulps where essentially all lignin was chemically removed (e.g., CPs). The diaper, which is not only made from chemical pulp but also contains some gel and plastic, exhibited limited biodegradability. The extent of biogenic carbon conversion varied from 21 to 96% among papers, which contrasts with the uniform assumption of 50% by the Intergovernmental Panel on Climate Change (IPCC) for all degradable materials discarded in landfills. Biochemical methane potential tests also showed that the solids to liquid ratio used in the test can influence the results.

  9. Effect of Landfill Leachate on Cereal Nutrition and Productivity and on Soil Properties.

    PubMed

    Panchoni, Luciana C; Santos, Cristiane A; Kuwano, Biana H; Carmo, Kellen B; Cely, Martha V T; Oliveira-Júnior, Admilton G; Fagotti, Dáfila S L; Cervantes, Vivian N M; Zangaro, Waldemar; Andrade, Diva S; Andrade, Galdino; Nogueira, Marco A

    2016-05-01

    Landfill leachates carry nutrients, especially N and K, which can be recycled in cropping systems. We applied doses of landfill leachate (0 [Control], 32.7, 65.4, 98.1, and 130.8 m ha) three times in 2008 and three times in 2009 on a clay Rhodic Kandiudult soil. In 2009, black oat ( L.) and corn ( L.) were cropped in succession and assessed for concentration of nutrients in leaves and for shoot biomass and grain yield, respectively. As a positive control, an additional treatment with urea (120 kg ha of N) was studied in corn. Soil was sampled at four depths (down to 60 cm) in three sampling dates to assess chemical and biochemical properties. Concentration of nutrients in leaves, oat biomass (8530-23,240 kg ha), and corn grain yield (4703-8807 kg ha) increased with increasing doses of leachate. There was a transient increase in the concentration of nitrate in soil (3-30 mg kg), increasing the risk of N losses by leaching at doses above 120 kg ha N, as revealed by an estimated N balance in the cropping system. Sodium and K in soil also increased with increasing doses of leachate but decreased as rainfall occurred. The activity of dehydrogenase decreased about 30% from the control to the highest dose of leachate and urea, suggesting an inhibitory effect of mineral N on microbial metabolism. Landfill leachate was promising as a source of N and K for crop productivity and caused minor or transient effects on soil properties. PMID:27136177

  10. Effect of Landfill Leachate on Cereal Nutrition and Productivity and on Soil Properties.

    PubMed

    Panchoni, Luciana C; Santos, Cristiane A; Kuwano, Biana H; Carmo, Kellen B; Cely, Martha V T; Oliveira-Júnior, Admilton G; Fagotti, Dáfila S L; Cervantes, Vivian N M; Zangaro, Waldemar; Andrade, Diva S; Andrade, Galdino; Nogueira, Marco A

    2016-05-01

    Landfill leachates carry nutrients, especially N and K, which can be recycled in cropping systems. We applied doses of landfill leachate (0 [Control], 32.7, 65.4, 98.1, and 130.8 m ha) three times in 2008 and three times in 2009 on a clay Rhodic Kandiudult soil. In 2009, black oat ( L.) and corn ( L.) were cropped in succession and assessed for concentration of nutrients in leaves and for shoot biomass and grain yield, respectively. As a positive control, an additional treatment with urea (120 kg ha of N) was studied in corn. Soil was sampled at four depths (down to 60 cm) in three sampling dates to assess chemical and biochemical properties. Concentration of nutrients in leaves, oat biomass (8530-23,240 kg ha), and corn grain yield (4703-8807 kg ha) increased with increasing doses of leachate. There was a transient increase in the concentration of nitrate in soil (3-30 mg kg), increasing the risk of N losses by leaching at doses above 120 kg ha N, as revealed by an estimated N balance in the cropping system. Sodium and K in soil also increased with increasing doses of leachate but decreased as rainfall occurred. The activity of dehydrogenase decreased about 30% from the control to the highest dose of leachate and urea, suggesting an inhibitory effect of mineral N on microbial metabolism. Landfill leachate was promising as a source of N and K for crop productivity and caused minor or transient effects on soil properties.

  11. Metal-modified and vertically aligned carbon nanotube sensors array for landfill gas monitoring applications.

    PubMed

    Penza, M; Rossi, R; Alvisi, M; Serra, E

    2010-03-12

    Vertically aligned carbon nanotube (CNT) layers were synthesized on Fe-coated low-cost alumina substrates using radio-frequency plasma enhanced chemical vapour deposition (RF-PECVD) technology. A miniaturized CNT-based gas sensor array was developed for monitoring landfill gas (LFG) at a temperature of 150 degrees C. The sensor array was composed of 4 sensing elements with unmodified CNT, and CNT loaded with 5 nm nominally thick sputtered nanoclusters of platinum (Pt), ruthenium (Ru) and silver (Ag). Chemical analysis of multicomponent gas mixtures constituted of CO(2), CH(4), H(2), NH(3), CO and NO(2) has been performed by the array sensor responses and pattern recognition based on principal component analysis (PCA). The PCA results demonstrate that the metal-decorated and vertically aligned CNT sensor array is able to discriminate the NO(2) presence in the multicomponent mixture LFG. The NO(2) gas detection in the mixture LFG was proved to be very sensitive, e.g.: the CNT:Ru sensor shows a relative change in the resistance of 1.50% and 0.55% for NO(2) concentrations of 3.3 ppm and 330 ppb dispersed in the LFG, respectively, with a wide NO(2) gas concentration range measured from 0.33 to 3.3 ppm, at the sensor temperature of 150 degrees C. The morphology and structure of the CNT networks have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. A forest-like nanostructure of vertically aligned CNT bundles in the multi-walled form appeared with a height of about 10 microm and a single-tube diameter varying in the range of 5-35 nm. The intensity ratio of the Raman spectroscopy D-peak and G-peak indicates the presence of disorder and defects in the CNT networks. The size of the metal (Pt, Ru, Ag) nanoclusters decorating the CNT top surface varies in the range of 5-50 nm. Functional characterization based on electrical charge transfer sensing mechanisms in the metal-modified CNT-chemoresistor array

  12. Effect of persistent trace compounds in landfill gas on engine performance during energy recovery: a case study.

    PubMed

    Sevimoğlu, Orhan; Tansel, Berrin

    2013-01-01

    Performances of gas engines operated with landfill gas (LFG) are affected by the impurities in the LFG, reducing the economic viability of energy recovery. The purpose of this study was to characterize the trace compounds in the LFG at the Odayeri Landfill, Istanbul, Turkey which is used for energy recovery. Composite gas samples were collected and analyzed for trace compounds (hydrocarbons, siloxanes, and volatile halogenated hydrocarbons) over a 3-year period. Trace compounds entering the gas engines, their impact on the engine performance were evaluated. The operational problems included deposit formation in the combustion chamber, turbocharger, and intercooler of engine before the scheduled maintenance times. High levels of hydrogen sulfide, as well as chlorinated and fluorinated compounds cause corrosion of the engine parts and decrease life of the engine oils. Persistence of siloxanes results in deposit formation, increasing engine maintenance costs. Pretreatment of LFG is necessary to protect the engines at the waste-to-energy facilities with persistence levels of siloxanes and volatile halogenated hydrocarbons.

  13. Greenhouse gas accounting of the proposed landfill extension and advanced incineration facility for municipal solid waste management in Hong Kong.

    PubMed

    Woon, K S; Lo, Irene M C

    2013-08-01

    The burgeoning of municipal solid waste (MSW) disposal issue and climate change have drawn massive attention from people. On the one hand, Hong Kong is facing a controversial debate over the implementation of proposed landfill extension (LFE) and advanced incineration facility (AIF) to curb the MSW disposal issue. On the other hand, the Hong Kong Special Administrative Region Government is taking concerted efforts to reduce the carbon intensity in this region. This paper discusses the greenhouse gas (GHG) emissions from four proposed waste disposal scenarios, covering the proposed LFE and AIF within a defined system boundary. On the basis of the data collected, assumptions made, and system boundary defined in this study, the results indicate that AIF releases less GHG emissions than LFE. The GHG emissions from LFE are highly contributed by the landfill methane (CH4) emissions but offset by biogenic carbon storage, while the GHG emissions from AIF are mostly due to the stack discharge system but offset by the energy recovery system. Furthermore, parametric sensitivity analyses show that GHG emissions are strongly dependent on the landfill CH4 recovery rate, types of electricity displaced by energy recovery systems, and the heating value of MSW, altering the order of preferred waste disposal scenarios. This evaluation provides valuable insights into the applicability of a policy framework for MSW management practices in reducing GHG emissions. PMID:23697849

  14. Greenhouse gas accounting of the proposed landfill extension and advanced incineration facility for municipal solid waste management in Hong Kong.

    PubMed

    Woon, K S; Lo, Irene M C

    2013-08-01

    The burgeoning of municipal solid waste (MSW) disposal issue and climate change have drawn massive attention from people. On the one hand, Hong Kong is facing a controversial debate over the implementation of proposed landfill extension (LFE) and advanced incineration facility (AIF) to curb the MSW disposal issue. On the other hand, the Hong Kong Special Administrative Region Government is taking concerted efforts to reduce the carbon intensity in this region. This paper discusses the greenhouse gas (GHG) emissions from four proposed waste disposal scenarios, covering the proposed LFE and AIF within a defined system boundary. On the basis of the data collected, assumptions made, and system boundary defined in this study, the results indicate that AIF releases less GHG emissions than LFE. The GHG emissions from LFE are highly contributed by the landfill methane (CH4) emissions but offset by biogenic carbon storage, while the GHG emissions from AIF are mostly due to the stack discharge system but offset by the energy recovery system. Furthermore, parametric sensitivity analyses show that GHG emissions are strongly dependent on the landfill CH4 recovery rate, types of electricity displaced by energy recovery systems, and the heating value of MSW, altering the order of preferred waste disposal scenarios. This evaluation provides valuable insights into the applicability of a policy framework for MSW management practices in reducing GHG emissions.

  15. Well-to-Wheels analysis of landfill gas-based pathways and their addition to the GREET model.

    SciTech Connect

    Mintz, M.; Han, J.; Wang, M.; Saricks, C.; Energy Systems

    2010-06-30

    Today, approximately 300 million standard cubic ft/day (mmscfd) of natural gas and 1600 MW of electricity are produced from the decomposition of organic waste at 519 U.S. landfills (EPA 2010a). Since landfill gas (LFG) is a renewable resource, this energy is considered renewable. When used as a vehicle fuel, compressed natural gas (CNG) produced from LFG consumes up to 185,000 Btu of fossil fuel and generates from 1.5 to 18.4 kg of carbon dioxide-equivalent (CO{sub 2}e) emissions per million Btu of fuel on a 'well-to-wheel' (WTW) basis. This compares with approximately 1.1 million Btu and 78.2 kg of CO{sub 2}e per million Btu for CNG from fossil natural gas and 1.2 million Btu and 97.5 kg of CO{sub 2}e per million Btu for petroleum gasoline. Because of the additional energy required for liquefaction, LFG-based liquefied natural gas (LNG) requires more fossil fuel (222,000-227,000 Btu/million Btu WTW) and generates more GHG emissions (approximately 22 kg CO{sub 2}e /MM Btu WTW) if grid electricity is used for the liquefaction process. However, if some of the LFG is used to generate electricity for gas cleanup and liquefaction (or compression, in the case of CNG), vehicle fuel produced from LFG can have no fossil fuel input and only minimal GHG emissions (1.5-7.7 kg CO{sub 2}e /MM Btu) on a WTW basis. Thus, LFG-based natural gas can be one of the lowest GHG-emitting fuels for light- or heavy-duty vehicles. This report discusses the size and scope of biomethane resources from landfills and the pathways by which those resources can be turned into and utilized as vehicle fuel. It includes characterizations of the LFG stream and the processes used to convert low-Btu LFG into high-Btu renewable natural gas (RNG); documents the conversion efficiencies and losses of those processes, the choice of processes modeled in GREET, and other assumptions used to construct GREET pathways; and presents GREET results by pathway stage. GREET estimates of well-to-pump (WTP), pump

  16. Application of conventional oil and gas drilling techniques to the production of gas from garbage

    SciTech Connect

    Giuliani, A.J.

    1980-01-01

    Although not a complete answer to the US's current energy problems, methane from sanitary landfills is one of the most economical substitute gas supplies. The methane-recovery state-of-the-art as applied at landfills now operating in California and New York and the construction of landfill wells and the various gas-extraction methods are discussed. Because landfill characteristics differ, the success of a methane-recovery operation depends on careful research, study, and initial testing of the specific site; additionally, cooperation is necessary at both government and industry levels. The most reliable route to utilization is to upgrade the landfill gas for blending with natural gas in a local distribution system or transmission line.

  17. BIOREACTOR LANDFILL DESIGN

    EPA Science Inventory

    Modern landfill design entails many elements including foundations, liner systems, leachate collection systems, stormwater control systems, slope stability considerations, leachate management systems, gas extraction systems, and capping and closure. The use of bioreactor technolo...

  18. Leaky Landfills.

    ERIC Educational Resources Information Center

    Jones, Linda L. Cronin

    1992-01-01

    Provides background information on landfills and describes an activity where students learn how a modern landfill is constructed and develop an understanding of the reasons for several regulations regarding modern landfill construction. Students design and construct working models of three types of landfills. (PR)

  19. Assessment of soil-gas, soil, and water contamination at the former hospital landfill, Fort Gordon, Georgia, 2009-2010

    USGS Publications Warehouse

    Falls, Fred W.; Caldwell, Andral W.; Guimaraes, Wladmir B.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    Soil gas, soil, and water were assessed for organic and inorganic constituents at the former hospital landfill located in a 75-acre study area near the Dwight D. Eisenhower Army Medical Center, Fort Gordon, Georgia, from April to September 2010. Passive soil-gas samplers were analyzed to evaluate organic constituents in the hyporheic zone of a creek adjacent to the landfill and soil gas within the estimated boundaries of the former landfill. Soil and water samples were analyzed to evaluate inorganic constituents in soil samples, and organic and inorganic constituents in the surface water of a creek adjacent to the landfill, respectively. This assessment was conducted to provide environmental constituent data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. Results from the hyporheic-zone assessment in the unnamed tributary adjacent to the study area indicated that total petroleum hydrocarbons and octane were the most frequently detected organic compounds in groundwater beneath the creek bed. The highest concentrations for these compounds were detected in the upstream samplers of the hyporheic-zone study area. The effort to delineate landfill activity in the study area focused on the western 14 acres of the 75-acre study area where the hyporheic-zone study identified the highest concentrations of organic compounds. This also is the part of the study area where a debris field also was identified in the southern part of the 14 acres. The southern part of this 14-acre study area, including the debris field, is steeper and not as heavily wooded, compared to the central and northern parts. Fifty-two soil-gas samplers were used for the July 2010 soil-gas survey in the 14-acre study area and mostly detected total petroleum hydrocarbons, and gasoline and diesel compounds. The highest soil-gas masses for total petroleum hydrocarbons, diesel compounds, and the only valid detection of perchloroethene

  20. Are closed landfills free of CH_{4} emissions? A case study of Arico's landfill, Tenerife, Canary Islands

    NASA Astrophysics Data System (ADS)

    Barrancos, José; Cook, Jenny; Phillips, Victoria; Asensio-Ramos, María; Melián, Gladys; Hernández, Pedro A.; Pérez, Nemesio M.

    2016-04-01

    Landfills are authentic chemical and biological reactors that introduce in the environment a wide amount of gas pollutants (CO2, CH4, volatile organic compounds, etc.) and leachates. Even after years of being closed, a significant amount of landfill gas could be released to the atmosphere through the surface in a diffuse form, also known as non-controlled emission. The study of the spatial-temporal distribution of diffuse emissions provides information of how a landfill degassing takes place. The main objective of this study was to estimate the diffuse uncontrolled emission of CH4 into the atmosphere from the closed Arico's landfill (0.3 km2) in Tenerife Island, Spain. To do so, a non-controlled biogenic gas emission survey of nearly 450 sampling sites was carried out during August 2015. Surface gas sampling and surface landfill CO2 efflux measurements were carried out at each sampling site by means of a portable non-dispersive infrared spectrophotometer (NDIR) model LICOR Li800 following the accumulation chamber method. Landfill gases, CO2 and CH4, were analyzed using a double channel VARIAN 4900 micro-GC. The CH4 efflux was computed combining CO2 efflux and CH4/CO2 ratio in the landfill's surface gas. To quantify the total CH4 emission, CH4 efflux contour map was constructed using sequential Gaussian simulation (sGs) as interpolation method. The total diffuse CH4 emission was estimated in 2.2 t d-1, with CH4 efflux values ranging from 0-922 mg m-2 d-1. This type of studies provides knowledge of how a landfill degasses and serves to public and private entities to establish effective systems for extraction of biogas. This aims not only to achieve higher levels of controlled gas release from landfills resulting in a higher level of energy production but also will contribute to minimize air pollution caused by them.

  1. Are closed landfills free of CH_{4} emissions? A case study of Arico's landfill, Tenerife, Canary Islands

    NASA Astrophysics Data System (ADS)

    Barrancos, José; Cook, Jenny; Phillips, Victoria; Asensio-Ramos, María; Melián, Gladys; Hernández, Pedro A.; Pérez, Nemesio M.

    2016-04-01

    Landfills are authentic chemical and biological reactors that introduce in the environment a wide amount of gas pollutants (CO2, CH4, volatile organic compounds, etc.) and leachates. Even after years of being closed, a significant amount of landfill gas could be released to the atmosphere through the surface in a diffuse form, also known as non-controlled emission. The study of the spatial-temporal distribution of diffuse emissions provides information of how a landfill degassing takes place. The main objective of this study was to estimate the diffuse uncontrolled emission of CH4 into the atmosphere from the closed Arico's landfill (0.3 km2) in Tenerife Island, Spain. To do so, a non-controlled biogenic gas emission survey of nearly 450 sampling sites was carried out during August 2015. Surface gas sampling and surface landfill CO2 efflux measurements were carried out at each sampling site by means of a portable non-dispersive infrared spectrophotometer (NDIR) model LICOR Li800 following the accumulation chamber method. Landfill gases, CO2 and CH4, were analyzed using a double channel VARIAN 4900 micro-GC. The CH4 efflux was computed combining CO2 efflux and CH4/CO2 ratio in the landfill's surface gas. To quantify the total CH4 emission, CH4 efflux contour map was constructed using sequential Gaussian simulation (sGs) as interpolation method. The total diffuse CH4 emission was estimated in 2.2 t d‑1, with CH4 efflux values ranging from 0-922 mg m‑2 d‑1. This type of studies provides knowledge of how a landfill degasses and serves to public and private entities to establish effective systems for extraction of biogas. This aims not only to achieve higher levels of controlled gas release from landfills resulting in a higher level of energy production but also will contribute to minimize air pollution caused by them.

  2. USING LANDFILL GAS IN FUEL CELLS - A STEP CLOSER TO COMMERICAL REALITY

    EPA Science Inventory

    The article discusses Phase II and Phase III results of a U.S. EPA program underway at International Fuel Cells Corporation. The program involves controlling methane emissions from landfills using a fuel cell. The fuel cell would reduce air emissions affecting global warming, aci...

  3. Cleaner Landfills

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Osmotek, Inc. developed the Direct Osmosis treatment system through SBIR funding from Ames Research Center. Using technology originally developed for flight aboard the Space Station, the company brought it to their commercial water purification treatment system, Direct Osmosis. This water purification system uses a direct osmosis process followed by a reverse osmosis treatment. Because the product extracts water from a waste product, Osmotek is marketing the unit for use in landfills. The system can treat leachate (toxic chemicals leached into a water source), by filtering the water and leaving behind the leahcate. The leachate then becomes solidified into substance that can not seep into water.

  4. Effects of dry bulk density and particle size fraction on gas transport parameters in variably saturated landfill cover soil.

    PubMed

    Wickramarachchi, Praneeth; Kawamoto, Ken; Hamamoto, Shoichiro; Nagamori, Masanao; Moldrup, Per; Komatsu, Toshiko

    2011-12-01

    Landfill sites are emerging in climate change scenarios as a significant source of greenhouse gases. The compacted final soil cover at landfill sites plays a vital role for the emission, fate and transport of landfill gases. This study investigated the effects of dry bulk density, ρ(b), and particle size fraction on the main soil-gas transport parameters - soil-gas diffusivity (D(p)/D(o), ratio of gas diffusion coefficients in soil and free air) and air permeability (k(a)) - under variably-saturated moisture conditions. Soil samples were prepared by three different compaction methods (Standard and Modified Proctor compaction, and hand compaction) with resulting ρ(b) values ranging from 1.40 to 2.10 g cm(-3). Results showed that D(p) and k(a) values for the '+gravel' fraction (<35 mm) became larger than for the '-gravel' fraction (<2mm) under variably-saturated conditions for a given soil-air content (ε), likely due to enhanced gas diffusion and advection through less tortuous, large-pore networks. The effect of dry bulk density on D(p) and k(a) was most pronounced for the '+gravel' fraction. Normalized ratios were introduced for all soil-gas parameters: (i) for gas diffusivity D(p)/D(f), the ratio of measured D(p) to D(p) in total porosity (f), (ii) for air permeability k(a)/k(a)(,pF4.1), the ratio of measured k(a) to k(a) at 1235 kPa matric potential (=pF 4.1), and (iii) for soil-air content, the ratio of soil-air content (ε) to total porosity (f) (air saturation). Based on the normalized parameters, predictive power-law models for D(p)(ε/f) and k(a)(ε/f) models were developed based on a single parameter (water blockage factor M for D(p) and P for k(a)). The water blockage factors, M and P, were found to be linearly correlated to ρ(b) values, and the effects of dry bulk density on D(p) and k(a) for both '+gravel' and '-gravel' fractions were well accounted for by the new models.

  5. 2D Time-lapse Resistivity Monitoring of an Organic Produced Gas Plume in a Landfill using ERT.

    NASA Astrophysics Data System (ADS)

    Amaral, N. D.; Mendonça, C. A.; Doherty, R.

    2014-12-01

    This project has the objective to study a landfill located on the margins of Tietê River, in São Paulo, Brazil, using the electroresistivity tomography method (ERT). Due to huge organic matter concentrations in the São Paulo Basin quaternary sediments, there is subsurface depth related biogas accumulation (CH4 and CO2), induced by anaerobic degradation of the organic matter. 2D resistivity sections were obtained from a test area since March 2012, a total of 7 databases, being the last one dated from October 2013. The studied line has the length of 56m, the electrode interval is of 2m. In addition, there are two boreholes along the line (one with 3 electrodes and the other one with 2) in order to improve data quality and precision. The boreholes also have a multi-level sampling system that indicates the fluid (gas or water) presence in relation to depth. With our results it was possible to map the gas plume position and its area of extension in the sections as it is a positive resistivity anomaly, with the gas level having approximately 5m depth. With the time-lapse analysis (Matlab script) between the obtained 2D resistivity sections from the site, it was possible to map how the biogas volume and position change in the landfill in relation to time. Our preliminary results show a preferential gas pathway through the subsurface studied area. A consistent relation between the gas depth and obtained microbiological data from archea and bacteria population was also observed.

  6. Impact of intermittent aerations on leachate quality and greenhouse gas reduction in the aerobic-anaerobic landfill method.

    PubMed

    Nag, Mitali; Shimaoka, Takayuki; Komiya, Teppei

    2016-09-01

    The aerobic-anaerobic landfill method (AALM) is a novel approach in solid waste management that could shorten the landfill post-closure period and minimize the environmental loads. In this study, the aerobic-anaerobic landfill method was evaluated by using intermittent aeration. In addition, the nitrification-denitrification process was assessed as a means of reducing the emission of greenhouse gases (GHGs) and improving the leachate quality during the degradation of the organic solid waste. The leachate quality and the gas composition in each of the reactors were measured during the experimental period (408days). The aeration process entailed the injection of air into plexiglass cylinders (200cm height×10 cm diameter), filled with fresh organic solid waste collected from a composting plant. Different aeration routines were applied, namely, continuous aeration (aerobic reactor A), aeration for three days/week (aerobic-anaerobic reactor B), aeration for 6h/day (aerobic-anaerobic reactor C), and no aeration (non-aerated reactor D). It was found that aerobic reactor A produced the best results in terms of reduction of GHGs and improvement of the leachate quality. The aerobic-anaerobic reactor C was found to be more effective than reactor B in respect of both the emission of GHGs and the leachate quality; moreover, compared with aerobic reactor A, energy costs were reduced by operating this reactor. The transition period phenomenon was investigated during an intensive seven-day experiment conducted on the discharged leachate obtained from aerobic-anaerobic reactors B and C. The experiment concerned the differences in the composition of the gas during the aeration and the non-aeration periods. It was found that the transition period between the aeration and non-aeration cycles, which followed the simultaneous nitrification-denitrification had a considerable effect on the leachate quality of both the reactors. The results indicated that AALM has the potential to reduce

  7. Impact of intermittent aerations on leachate quality and greenhouse gas reduction in the aerobic-anaerobic landfill method.

    PubMed

    Nag, Mitali; Shimaoka, Takayuki; Komiya, Teppei

    2016-09-01

    The aerobic-anaerobic landfill method (AALM) is a novel approach in solid waste management that could shorten the landfill post-closure period and minimize the environmental loads. In this study, the aerobic-anaerobic landfill method was evaluated by using intermittent aeration. In addition, the nitrification-denitrification process was assessed as a means of reducing the emission of greenhouse gases (GHGs) and improving the leachate quality during the degradation of the organic solid waste. The leachate quality and the gas composition in each of the reactors were measured during the experimental period (408days). The aeration process entailed the injection of air into plexiglass cylinders (200cm height×10 cm diameter), filled with fresh organic solid waste collected from a composting plant. Different aeration routines were applied, namely, continuous aeration (aerobic reactor A), aeration for three days/week (aerobic-anaerobic reactor B), aeration for 6h/day (aerobic-anaerobic reactor C), and no aeration (non-aerated reactor D). It was found that aerobic reactor A produced the best results in terms of reduction of GHGs and improvement of the leachate quality. The aerobic-anaerobic reactor C was found to be more effective than reactor B in respect of both the emission of GHGs and the leachate quality; moreover, compared with aerobic reactor A, energy costs were reduced by operating this reactor. The transition period phenomenon was investigated during an intensive seven-day experiment conducted on the discharged leachate obtained from aerobic-anaerobic reactors B and C. The experiment concerned the differences in the composition of the gas during the aeration and the non-aeration periods. It was found that the transition period between the aeration and non-aeration cycles, which followed the simultaneous nitrification-denitrification had a considerable effect on the leachate quality of both the reactors. The results indicated that AALM has the potential to reduce

  8. Enhancement of methane production and bio-stabilisation of municipal solid waste in anaerobic bioreactor landfill.

    PubMed

    Mali Sandip, T; Khare Kanchan, C; Biradar Ashok, H

    2012-04-01

    The aim of the experiment was to enhance biodegradation and methane production of municipal solid waste (MSW). Two groups of simulated anaerobic bioreactor landfill were used; one group of mixed MSW with three bioreactors (R1, R2 and R3) and second group was compostable MSW with two bioreactors (R4 and R5). The different combinations of operational parameters were aeration with addition of aerobic microbial culture, anaerobic sludge, coarse gravel mixing, intermediate soil cover and varied leachate recirculation rate. The results observed at the end of 270days prevail that the process combination of above operational parameters adopted in compostable MSW bioreactor was more efficient approach for stabilization of MSW. It has accelerated the methane production rate (141.28Lkg(-1)dry waste) by 25%. It was also observed that the degradation time of MSW was reduced by 25% compared to maximum values quoted in the literature. The nonlinear regression of the cumulative biogas production and digestion time shows that Gompertz growth equation fits the results well. PMID:22342079

  9. LANDFILL GAS CONVERSION TO LNG AND LCO{sub 2}. PHASE 1, FINAL REPORT FOR THE PERIOD MARCH 1998-FEBRUARY 1999

    SciTech Connect

    COOK,W.J.; NEYMAN,M.; SIWAJEK,L.A.; BROWN,W.R.; VAN HAUWAERT,P.M.; CURREN,E.D.

    1998-02-25

    Process designs and economics were developed to produce LNG and liquid carbon dioxide (CO{sub 2}) from landfill gas (LFG) using the Acrion CO{sub 2} wash process. The patented Acrion CO{sub 2} wash process uses liquid CO{sub 2} to absorb contaminants from the LFG. The process steps are compression, drying, CO{sub 2} wash contaminant removal and CO{sub 2} recovery, residual CO{sub 2} removal and methane liquefaction. Three flowsheets were developed using different residual CO{sub 2} removal schemes. These included physical solvent absorption (methanol), membranes and molecular sieves. The capital and operating costs of the flowsheets were very similar. The LNG production cost was around ten cents per gallon. In parallel with process flowsheet development, the business aspects of an eventual commercial project have been explored. The process was found to have significant potential commercial application. The business plan effort investigated the economics of LNG transportation, fueling, vehicle conversion, and markets. The commercial value of liquid CO{sub 2} was also investigated. This Phase 1 work, March 1998 through February 1999, was funded under Brookhaven National laboratory contract 725089 under the research program entitled ``Liquefied Natural Gas as a Heavy Vehicle Fuel.'' The Phase 2 effort will develop flowsheets for the following: (1) CO{sub 2} and pipeline gas production, with the pipeline methane being liquefied at a peak shaving site, (2) sewage digester gas as an alternate feedstock to LFG and (3) the use of mixed refrigerants for process cooling. Phase 2 will also study the modification of Acrion's process demonstration unit for the production of LNG and a market site for LNG production.

  10. Stochastic modelling of landfill leachate and biogas production incorporating waste heterogeneity. Model formulation and uncertainty analysis.

    PubMed

    Zacharof, A I; Butler, A P

    2004-01-01

    A mathematical model simulating the hydrological and biochemical processes occurring in landfilled waste is presented and demonstrated. The model combines biochemical and hydrological models into an integrated representation of the landfill environment. Waste decomposition is modelled using traditional biochemical waste decomposition pathways combined with a simplified methodology for representing the rate of decomposition. Water flow through the waste is represented using a statistical velocity model capable of representing the effects of waste heterogeneity on leachate flow through the waste. Given the limitations in data capture from landfill sites, significant emphasis is placed on improving parameter identification and reducing parameter requirements. A sensitivity analysis is performed, highlighting the model's response to changes in input variables. A model test run is also presented, demonstrating the model capabilities. A parameter perturbation model sensitivity analysis was also performed. This has been able to show that although the model is sensitive to certain key parameters, its overall intuitive response provides a good basis for making reasonable predictions of the future state of the landfill system. Finally, due to the high uncertainty associated with landfill data, a tool for handling input data uncertainty is incorporated in the model's structure. It is concluded that the model can be used as a reasonable tool for modelling landfill processes and that further work should be undertaken to assess the model's performance. PMID:15120429

  11. Effect of salinity on N₂O production during shortcut biological nitrogen removal from landfill leachate.

    PubMed

    Liu, Mu; Liu, Tiantian; Peng, Yongzhen; Wang, Shuying; Xiao, Han

    2014-05-01

    Three identical SBR adapted to different salinity were applied to investigate the characteristics of the treatment performance and N2O production [Formula: see text] during shortcut biological nitrogen removal from landfill leachate under various operating parameters. Increase of salinity might deteriorate the activity of the microorganisms leading to the increase of [Formula: see text] , however, the system could be gradually adapted to the inhibition and alleviate the detrimental effect to some extent. The system acclimated to high salinity provided better performance under high salinity shock and a lower possibility of [Formula: see text] , while a sudden decrease in salinity can cause a temporary increase in [Formula: see text] . High salinity strengthened the influence of high ammonia nitrogen concentration and low DO concentration on [Formula: see text] while the strengthening effect was unconspicuous at high DO concentration. The anoxic phase did not produce a significant amount of N2O even at the lowest C/N ratio of 0.5 and was less susceptible to salinity. Characterization of the biomass composition using fluorescence in situ hybridization analysis confirmed that the relative proportion of Nitrosomonas europaea was increased with the increase of the salinity, which may be an important factor for the strengthening effect of salinity on [Formula: see text] . PMID:24225121

  12. Effect of salinity on N₂O production during shortcut biological nitrogen removal from landfill leachate.

    PubMed

    Liu, Mu; Liu, Tiantian; Peng, Yongzhen; Wang, Shuying; Xiao, Han

    2014-05-01

    Three identical SBR adapted to different salinity were applied to investigate the characteristics of the treatment performance and N2O production [Formula: see text] during shortcut biological nitrogen removal from landfill leachate under various operating parameters. Increase of salinity might deteriorate the activity of the microorganisms leading to the increase of [Formula: see text] , however, the system could be gradually adapted to the inhibition and alleviate the detrimental effect to some extent. The system acclimated to high salinity provided better performance under high salinity shock and a lower possibility of [Formula: see text] , while a sudden decrease in salinity can cause a temporary increase in [Formula: see text] . High salinity strengthened the influence of high ammonia nitrogen concentration and low DO concentration on [Formula: see text] while the strengthening effect was unconspicuous at high DO concentration. The anoxic phase did not produce a significant amount of N2O even at the lowest C/N ratio of 0.5 and was less susceptible to salinity. Characterization of the biomass composition using fluorescence in situ hybridization analysis confirmed that the relative proportion of Nitrosomonas europaea was increased with the increase of the salinity, which may be an important factor for the strengthening effect of salinity on [Formula: see text] .

  13. Mobile Robots for Localizing Gas Emission Sources on Landfill Sites: Is Bio-Inspiration the Way to Go?

    PubMed Central

    Hernandez Bennetts, Victor; Lilienthal, Achim J.; Neumann, Patrick P.; Trincavelli, Marco

    2011-01-01

    Roboticists often take inspiration from animals for designing sensors, actuators, or algorithms that control the behavior of robots. Bio-inspiration is motivated with the uncanny ability of animals to solve complex tasks like recognizing and manipulating objects, walking on uneven terrains, or navigating to the source of an odor plume. In particular the task of tracking an odor plume up to its source has nearly exclusively been addressed using biologically inspired algorithms and robots have been developed, for example, to mimic the behavior of moths, dung beetles, or lobsters. In this paper we argue that biomimetic approaches to gas source localization are of limited use, primarily because animals differ fundamentally in their sensing and actuation capabilities from state-of-the-art gas-sensitive mobile robots. To support our claim, we compare actuation and chemical sensing available to mobile robots to the corresponding capabilities of moths. We further characterize airflow and chemosensor measurements obtained with three different robot platforms (two wheeled robots and one flying micro-drone) in four prototypical environments and show that the assumption of a constant and unidirectional airflow, which is the basis of many gas source localization approaches, is usually far from being valid. This analysis should help to identify how underlying principles, which govern the gas source tracking behavior of animals, can be usefully “translated” into gas source localization approaches that fully take into account the capabilities of mobile robots. We also describe the requirements for a reference application, monitoring of gas emissions at landfill sites with mobile robots, and discuss an engineered gas source localization approach based on statistics as an alternative to biologically inspired algorithms. PMID:22319493

  14. Mobile robots for localizing gas emission sources on landfill sites: is bio-inspiration the way to go?

    PubMed

    Hernandez Bennetts, Victor; Lilienthal, Achim J; Neumann, Patrick P; Trincavelli, Marco

    2011-01-01

    Roboticists often take inspiration from animals for designing sensors, actuators, or algorithms that control the behavior of robots. Bio-inspiration is motivated with the uncanny ability of animals to solve complex tasks like recognizing and manipulating objects, walking on uneven terrains, or navigating to the source of an odor plume. In particular the task of tracking an odor plume up to its source has nearly exclusively been addressed using biologically inspired algorithms and robots have been developed, for example, to mimic the behavior of moths, dung beetles, or lobsters. In this paper we argue that biomimetic approaches to gas source localization are of limited use, primarily because animals differ fundamentally in their sensing and actuation capabilities from state-of-the-art gas-sensitive mobile robots. To support our claim, we compare actuation and chemical sensing available to mobile robots to the corresponding capabilities of moths. We further characterize airflow and chemosensor measurements obtained with three different robot platforms (two wheeled robots and one flying micro-drone) in four prototypical environments and show that the assumption of a constant and unidirectional airflow, which is the basis of many gas source localization approaches, is usually far from being valid. This analysis should help to identify how underlying principles, which govern the gas source tracking behavior of animals, can be usefully "translated" into gas source localization approaches that fully take into account the capabilities of mobile robots. We also describe the requirements for a reference application, monitoring of gas emissions at landfill sites with mobile robots, and discuss an engineered gas source localization approach based on statistics as an alternative to biologically inspired algorithms.

  15. Metal loss from treated wood products in contact with municipal solid waste landfill leachate.

    PubMed

    Dubey, Brajesh; Townsend, Timothy; Solo-Gabriele, Helena

    2010-03-15

    The research presented in this paper evaluates the potential impact of municipal solid waste (MSW) landfill leachate quality on the loss of metals from discarded treated wood during disposal. The loss of arsenic (As), chromium (Cr), copper (Cu), and boron (B) from several types of pressure-treated wood (CCA: chromated copper arsenate, ACQ: alkaline copper quaternary, CBA: copper boron azole, and DOT: disodium octaborate tetrahydrate) using leachate collected from 26 MSW landfills in Florida was examined. The toxicity characteristic leaching procedure (TCLP), the synthetic precipitation leaching procedure (SPLP), and California's waste extraction test (WET) were also performed. The results suggested that loss of preservative components was influenced by leachate chemistry. Copper loss from CCA-, ACQ- and CBA-treated wood was similar in magnitude when in contact with landfill leachates compared to synthetic TCLP and SPLP solutions. Ammonia was found as one of the major parameters influencing the leaching of Cu from treated wood when leached with MSW landfill leachates. The results suggest that disposal of ACQ- and CBA-treated wood in substantial quantity in MSW landfills may elevate the Cu concentration in the leachate; this could be of potential concern, especially for a bioreactor MSW landfill in which relatively higher ammonia concentrations in leachate have been reported in recent literature. For the As, Cr and B the concentrations observed with the landfill leachate as the leaching solutions were over a range from some sample showing the concentrations below and some showing above the observed value from corresponding SPLP and TCLP tests. In general the WET test showed the highest concentrations. PMID:19910117

  16. Metal loss from treated wood products in contact with municipal solid waste landfill leachate.

    PubMed

    Dubey, Brajesh; Townsend, Timothy; Solo-Gabriele, Helena

    2010-03-15

    The research presented in this paper evaluates the potential impact of municipal solid waste (MSW) landfill leachate quality on the loss of metals from discarded treated wood during disposal. The loss of arsenic (As), chromium (Cr), copper (Cu), and boron (B) from several types of pressure-treated wood (CCA: chromated copper arsenate, ACQ: alkaline copper quaternary, CBA: copper boron azole, and DOT: disodium octaborate tetrahydrate) using leachate collected from 26 MSW landfills in Florida was examined. The toxicity characteristic leaching procedure (TCLP), the synthetic precipitation leaching procedure (SPLP), and California's waste extraction test (WET) were also performed. The results suggested that loss of preservative components was influenced by leachate chemistry. Copper loss from CCA-, ACQ- and CBA-treated wood was similar in magnitude when in contact with landfill leachates compared to synthetic TCLP and SPLP solutions. Ammonia was found as one of the major parameters influencing the leaching of Cu from treated wood when leached with MSW landfill leachates. The results suggest that disposal of ACQ- and CBA-treated wood in substantial quantity in MSW landfills may elevate the Cu concentration in the leachate; this could be of potential concern, especially for a bioreactor MSW landfill in which relatively higher ammonia concentrations in leachate have been reported in recent literature. For the As, Cr and B the concentrations observed with the landfill leachate as the leaching solutions were over a range from some sample showing the concentrations below and some showing above the observed value from corresponding SPLP and TCLP tests. In general the WET test showed the highest concentrations.

  17. Effects of dry bulk density and particle size fraction on gas transport parameters in variably saturated landfill cover soil

    SciTech Connect

    Wickramarachchi, Praneeth; Kawamoto, Ken; Hamamoto, Shoichiro; Nagamori, Masanao; Moldrup, Per; Komatsu, Toshiko

    2011-12-15

    Highlights: > The effects of soil physical properties on gas transport parameters were investigated. > Higher values of D{sub p} and k{sub a} exhibited in the '+gravel' than the '-gravel' fraction at same soil-air content ({epsilon}). > Recent power law models for D{sub p} (WLR) and k{sub a} (RPL) were modified. > Model parameters were linearly related to easily measurable dry bulk density ({rho}{sub b}). - Abstract: Landfill sites are emerging in climate change scenarios as a significant source of greenhouse gases. The compacted final soil cover at landfill sites plays a vital role for the emission, fate and transport of landfill gases. This study investigated the effects of dry bulk density, {rho}{sub b}, and particle size fraction on the main soil-gas transport parameters - soil-gas diffusivity (D{sub p}/D{sub o}, ratio of gas diffusion coefficients in soil and free air) and air permeability (k{sub a}) - under variably-saturated moisture conditions. Soil samples were prepared by three different compaction methods (Standard and Modified Proctor compaction, and hand compaction) with resulting {rho}{sub b} values ranging from 1.40 to 2.10 g cm{sup -3}. Results showed that D{sub p} and k{sub a} values for the '+gravel' fraction (<35 mm) became larger than for the '-gravel' fraction (<2 mm) under variably-saturated conditions for a given soil-air content ({epsilon}), likely due to enhanced gas diffusion and advection through less tortuous, large-pore networks. The effect of dry bulk density on D{sub p} and k{sub a} was most pronounced for the '+gravel' fraction. Normalized ratios were introduced for all soil-gas parameters: (i) for gas diffusivity D{sub p}/D{sub f}, the ratio of measured D{sub p} to D{sub p} in total porosity (f), (ii) for air permeability k{sub a}/k{sub a,pF4.1}, the ratio of measured k{sub a} to k{sub a} at 1235 kPa matric potential (=pF 4.1), and (iii) for soil-air content, the ratio of soil-air content ({epsilon}) to total porosity (f) (air

  18. Determination of nonylphenol isomers in landfill leachate and municipal wastewater using steam distillation extraction coupled with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry

    USGS Publications Warehouse

    Zhang, Caixiang; Eganhouse, Robert P.; Pontolillo, James; Cozzarelli, Isabelle M.; Wang, Yanxin

    2012-01-01

    4-Nonylphenols (4-NPs) are known endocrine disruptors and by-products of the microbial degradation of nonylphenol polyethoxylate surfactants. One of the challenges to understanding the toxic effects of nonylphenols is the large number of isomers that may exist in environmental samples. In order to attribute toxic effects to specific compounds, a method is needed for the separation and quantitation of individual nonylphenol isomers. The pre-concentration methods of solvent sublimation, solid-phase extraction or liquid–liquid extraction prior to chromatographic analysis can be problematic because of co-extraction of thousands of compounds typically found in complex matrices such as municipal wastewater or landfill leachate. In the present study, steam distillation extraction (SDE) was found to be an effective pre-concentration method for extraction of 4-NPs from leachate and wastewater, and comprehensive two-dimensional gas chromatography (GC × GC) coupled with fast mass spectral data acquisition by time-of-flight mass spectrometry (ToFMS) enhanced the resolution and identification of 4-NP isomers. Concentrations of eight 4-NP isomers were determined in leachate from landfill cells of different age and wastewater influent and effluent samples. 4-NP isomers were about 3 times more abundant in leachate from the younger cell than the older one, whereas concentrations in wastewater effluent were either below detection limits or <1% of influent concentrations. 4-NP isomer distribution patterns were found to have been altered following release to the environment. This is believed to reflect isomer-specific degradation and accumulation of 4-NPs in the aquatic environment.

  19. Determination of nonylphenol isomers in landfill leachate and municipal wastewater using steam distillation extraction coupled with comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry.

    PubMed

    Zhang, Caixiang; Eganhouse, Robert P; Pontolillo, James; Cozzarelli, Isabelle M; Wang, Yanxin

    2012-03-23

    4-Nonylphenols (4-NPs) are known endocrine disruptors and by-products of the microbial degradation of nonylphenol polyethoxylate surfactants. One of the challenges to understanding the toxic effects of nonylphenols is the large number of isomers that may exist in environmental samples. In order to attribute toxic effects to specific compounds, a method is needed for the separation and quantitation of individual nonylphenol isomers. The pre-concentration methods of solvent sublimation, solid-phase extraction or liquid-liquid extraction prior to chromatographic analysis can be problematic because of co-extraction of thousands of compounds typically found in complex matrices such as municipal wastewater or landfill leachate. In the present study, steam distillation extraction (SDE) was found to be an effective pre-concentration method for extraction of 4-NPs from leachate and wastewater, and comprehensive two-dimensional gas chromatography (GC×GC) coupled with fast mass spectral data acquisition by time-of-flight mass spectrometry (ToFMS) enhanced the resolution and identification of 4-NP isomers. Concentrations of eight 4-NP isomers were determined in leachate from landfill cells of different age and wastewater influent and effluent samples. 4-NP isomers were about 3 times more abundant in leachate from the younger cell than the older one, whereas concentrations in wastewater effluent were either below detection limits or <1% of influent concentrations. 4-NP isomer distribution patterns were found to have been altered following release to the environment. This is believed to reflect isomer-specific degradation and accumulation of 4-NPs in the aquatic environment.

  20. EIA's Natural Gas Production Data

    EIA Publications

    2009-01-01

    This special report examines the stages of natural gas processing from the wellhead to the pipeline network through which the raw product becomes ready for transportation and eventual consumption, and how this sequence is reflected in the data published by the Energy Information Administration (EIA).

  1. Measuring Water in Bioreactor Landfills

    NASA Astrophysics Data System (ADS)

    Han, B.; Gallagher, V. N.; Imhoff, P. T.; Yazdani, R.; Chiu, P.

    2004-12-01

    Methane is an important greenhouse gas, and landfills are the largest anthropogenic source in many developed countries. Bioreactor landfills have been proposed as one means of abating greenhouse gas emissions from landfills. Here, the decomposition of organic wastes is enhanced by the controlled addition of water or leachate to maintain optimal conditions for waste decomposition. Greenhouse gas abatement is accomplished by sequestration of photosynthetically derived carbon in wastes, CO2 offsets from energy use of waste derived gas, and mitigation of methane emission from the wastes. Maintaining optimal moisture conditions for waste degradation is perhaps the most important operational parameter in bioreactor landfills. To determine how much water is needed and where to add it, methods are required to measure water within solid waste. However, there is no reliable method that can measure moisture content simply and accurately in the heterogeneous environment typical of landfills. While well drilling and analysis of solid waste samples is sometimes used to determine moisture content, this is an expensive, time-consuming, and destructive procedure. To overcome these problems, a new technology recently developed by hydrologists for measuring water in the vadose zone --- the partitioning tracer test (PTT) --- was evaluated for measuring water in solid waste in a full-scale bioreactor landfill in Yolo County, CA. Two field tests were conducted in different regions of an aerobic bioreactor landfill, with each test measuring water in ≈ 250 ft3 of solid waste. Tracers were injected through existing tubes inserted in the landfill, and tracer breakthrough curves were measured through time from the landfill's gas collection system. Gas samples were analyzed on site using a field-portable gas chromatograph and shipped offsite for more accurate laboratory analysis. In the center of the landfill, PTT measurements indicated that the fraction of the pore space filled with water

  2. Emissions of organo-metal compounds via the leachate and gas pathway from two differently pre-treated municipal waste materials - A landfill reactor study

    SciTech Connect

    Michalzik, B. Ilgen, G.; Hertel, F.; Hantsch, S.; Bilitewski, B.

    2007-07-01

    Due to their broad industrial production and use as PVC-stabilisers, agro-chemicals and anti-fouling agents, organo-metal compounds are widely distributed throughout the terrestrial and marine biogeosphere. Here, we focused on the emission dynamics of various organo-metal compounds (e.g., di,- tri-, tetra-methyl tin, di-methyl mercury, tetra-methyl lead) from two different kinds of pre-treated mass waste, namely mechanically-biologically pre-treated municipal solid waste (MBP MSW) and municipal waste incineration ash (MWIA). In landfill simulation reactors, the emission of the organo-metal compounds via the leachate and gas pathway was observed over a period of 5 months simulating different environmental conditions (anaerobic with underlying soil layer/aerated/anaerobic). Both waste materials differ significantly in their initial amounts of organo-metal compounds and their environmental behaviour with regard to the accumulation and depletion rates within the solid material during incubation. For tri-methyl tin, the highest release rates in leachates were found in the incineration ash treatments, where anaerobic conditions in combination with underlying soil material significantly promoted its formation. Concerning the gas pathway, anaerobic conditions considerably favour the emission of organo-metal compounds (tetra-methyl tin, di-methyl mercury, tetra-methyl lead) in both the MBP material and especially in the incineration ash.

  3. Air emissions assessment and air quality permitting for a municipal waste landfill treating municipal sewage sludge

    SciTech Connect

    Koehler, J.

    1998-12-31

    This paper presents a case study into the air quality permitting of a municipal solid waste (MSW) landfill in the San Francisco Bay Area undergoing a proposed expansion in operations to increase the life of the landfill. The operations of this facility include MSW landfilling, the treatment and disposal of municipal sewage sludge, the aeration of petroleum-contaminated soils, the construction of a new on-site plant to manufacture soil amendment products from waste wood and other organic material diverted from the landfill, and the installation of a vaporator to create steam from leachate for injection into the landfill gas flare. The emissions assessment for each project component relied upon interpretation of source tests from similar operations, incorporation of on-site measurements into emissions models and mass balances, and use of AP-42 procedures for emissions sources such as wind-blown dust, material handling and transfer operations, and fugitive landfill gas. Air permitting issues included best available control technology (BACT), emission offset thresholds, new source performance standards (NSPS), potential air toxics health risk impacts, and compliance with federal Title V operating permit requirements. With the increasing difficulties of siting new landfills, increasing pressures to reduce the rate of waste placement into existing landfills, and expanding regulatory requirements on landfill operations, experiences similar to those described in this paper are likely to increase in the future as permitting scenarios become more complex.

  4. Nitrogen management in bioreactor landfills

    SciTech Connect

    Price, G. Alexander; Barlaz, Morton A.; Hater, Gary R

    2003-07-01

    One scenario for long-term nitrogen management in landfills is ex situ nitrification followed by denitrification in the landfill. The objective of this research was to measure the denitrification potential of actively decomposing and well decomposed refuse. A series of 10-l reactors that were actively producing methane were fed 400 mg NO{sub 3}-N /l every 48 h for periods of 19-59 days. Up to 29 nitrate additions were either completely or largely depleted within 48 h of addition and the denitrification reactions did not adversely affect the leachate pH. Nitrate did inhibit methane production, but the reactors recovered their methane-producing activity with the termination of nitrate addition. In well decomposed refuse, the nitrate consumption rate was reduced but was easily stimulated by the addition of either acetate or an overlayer of fresh refuse. Addition of acetate at five times the amount required to reduce nitrate did not lead to the production of NH{sub 4}{sup +} by dissimilatory nitrate reduction. The most probable number of denitrifying bacteria decreased by about five orders of magnitude during refuse decomposition in a reactor that did not receive nitrate. However, rapid denitrification commenced immediately with nitrate addition. This study shows that the use of a landfill as a bioreactor for the conversion of nitrate to a harmless byproduct, nitrogen gas, is technically viable.

  5. Organics removal from landfill leachate and activated sludge production in SBR reactors

    SciTech Connect

    Klimiuk, Ewa; Kulikowska, Dorota . E-mail: dorotak@uwm.edu.pl

    2006-07-01

    This study is aimed at estimating organic compounds removal and sludge production in SBR during treatment of landfill leachate. Four series were performed. At each series, experiments were carried out at the hydraulic retention time (HRT) of 12, 6, 3 and 2 d. The series varied in SBR filling strategies, duration of the mixing and aeration phases, and the sludge age. In series 1 and 2 (a short filling period, mixing and aeration phases in the operating cycle), the relationship between organics concentration (COD) in the leachate treated and HRT was pseudo-first-order kinetics. In series 3 (with mixing and aeration phases) and series 4 (only aeration phase) with leachate supplied by means of a peristaltic pump for 4 h of the cycle (filling during reaction period) - this relationship was zero-order kinetics. Activated sludge production expressed as the observed coefficient of biomass production (Y {sub obs}) decreased correspondingly with increasing HRT. The smallest differences between reactors were observed in series 3 in which Y {sub obs} was almost stable (0.55-0.6 mg VSS/mg COD). The elimination of the mixing phase in the cycle (series 4) caused the Y {sub obs} to decrease significantly from 0.32 mg VSS/mg COD at HRT 2 d to 0.04 mg VSS/mg COD at HRT 12 d. The theoretical yield coefficient Y accounted for 0.534 mg VSS/mg COD (series 1) and 0.583 mg VSS/mg COD (series 2). In series 3 and 4, it was almost stable (0.628 mg VSS/mg COD and 0.616 mg VSS/mg COD, respectively). After the elimination of the mixing phase in the operating cycle, the specific biomass decay rate increased from 0.006 d{sup -1} (series 3) to 0.032 d{sup -1} (series 4). The operating conditions employing mixing/aeration or only aeration phases enable regulation of the sludge production. The SBRs operated under aerobic conditions are more favourable at a short hydraulic retention time. At long hydraulic retention time, it can lead to a decrease in biomass concentration in the SBR as a result of

  6. Lubrication contributes to improved landfill cogeneration plant operation

    SciTech Connect

    1995-10-01

    The Prince George`s county, Maryland, cogeneration plant consists of three lean-burn, 12-cylinder, Waukesha 5790GL turbocharged gas engines, each powering an 850 kW Kato generator. Four Waukesha F1197G engines run gas compressors that draw and compress gas from the landfill, pumping an average of 28000 m{sup 3}/day at 6.2 bar from 29 wells. Landfill gas is 50% methane, 30% carbon dioxide, 10% nitrogen and 10% other gas constituents. These other gas constituents consist of 160 chemical compounds, many of which are very destructive to engines and other equipment. Probably the worst of these are the total organic halide expressed as chloride (TOH/CL), formed from the decomposition of household cleaning preparations and other materials containing chlorides. Landfill gas also contains an abundance of water, which combines not only with the TOH/CLs but with oxides of nitrogen, which are by-products of the combustion process, to form acids. To handle the highly contaminated landfill gas, the Waukesha Engine Division and people from Curtis Engine and Equipment modified the equipment and maintenance practices. One of the first changes was in lubrication. Curtis switched from a standard gas engine oil to Mobile Pegasus 446 oil, an SAE 40 oil that has a total base number (TBN) of 9.5, because of its extended acid-neutralizing capabilities.

  7. [Physical and chemical properties of land-filling pile and aged refuse in 5-year-old semi-aerobic and anaerobic landfills].

    PubMed

    Zhang, Wei; Yue, Bo; Huang, Qi-Fei; Huang, Ze-Chun; Zhang, Zeng-Qiang; Wang, Qi; Lin, Ye; Wang, Jin-An

    2010-03-01

    This paper studied the surface settlement, temperature, and gas production of land-filling pile, and the physical and chemical properties of aged refuse in 5-year-old semi-aerobic and anaerobic landfills. The pile's surface settlement and its volume reduction rate were significantly higher in semi-aerobic than in anaerobic landfill; and the treatment with leachate recycling brought larger uneven settlement than the treatment with water recycling. The temperature of anaerobic landfill pile (25.6 degrees C) was slightly higher than that of semi-aerobic landfill file (24.8 degrees C), but the difference was not significant. During land-filling period, the O2 concentration in semi-aerobic landfill pile was significantly higher than that in anaerobic one, while the CH4 concentration was in reverse. After 5 years land-filling, the contents of easily degradable organic matters in aged refuse, such as kitchen refuses and papers, decreased dramatically, while the contents of plastics, glasses, bricks, and woods increased. In addition, the contents of organic matters and nutrients in aged refuse were higher than those in typical southern China soils, and the concentrations of heavy metals except chromium in anaerobic landfill aged refuse were not beyond the grade three of Environmental Quality Standards for Soils (GB 15618-1995).

  8. LANDFILL BIOREACTOR PERFORMANCE, SECOND INTERIM REPORT

    EPA Science Inventory

    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. METHANE PHYTOREMEDIATION BY VEGETATIVE LANDFILL COVER SYSTEMS

    EPA Science Inventory

    Landfill gas, consisting of methane and other gases, is produced from organic compounds degrading in landfills, contributes to global climate change, is toxic to various types of vegetation, and may pose a combustion hazard at higher concentrations. New landfills are required to ...

  10. Desulfurized gas production from vertical kiln pyrolysis

    DOEpatents

    Harris, Harry A.; Jones, Jr., John B.

    1978-05-30

    A gas, formed as a product of a pyrolysis of oil shale, is passed through hot, retorted shale (containing at least partially decomposed calcium or magnesium carbonate) to essentially eliminate sulfur contaminants in the gas. Specifically, a single chambered pyrolysis vessel, having a pyrolysis zone and a retorted shale gas into the bottom of the retorted shale zone and cleaned product gas is withdrawn as hot product gas near the top of such zone.

  11. Using observed data to improve estimated methane collection from select U.S. landfills.

    PubMed

    Wang, Xiaoming; Nagpure, Ajay S; DeCarolis, Joseph F; Barlaz, Morton A

    2013-04-01

    The anaerobic decomposition of solid waste in a landfill produces methane, a potent greenhouse gas, and if recovered, a valuable energy commodity. Methane generation from U.S. landfills is usually estimated using the U.S. EPA's Landfill Gas Emissions Model (LandGEM). Default values for the two key parameters within LandGEM, the first-order decay rate (k) and the methane production potential (L0) are based on data collected in the 1990s. In this study, observed methane collection data from 11 U.S. landfills and estimates of gas collection efficiencies developed from site-specific gas well installation data were included in a reformulated LandGEM equation. Formal search techniques were employed to optimize k for each landfill to find the minimum sum of squared errors (SSE) between the LandGEM prediction and the observed collection data. Across nearly all landfills, the optimal k was found to be higher than the default AP-42 of 0.04 yr(-1) and the weighted average decay for the 11 landfills was 0.09 - 0.12 yr(-1). The results suggest that the default k value assumed in LandGEM is likely too low, which implies that more methane is produced in the early years following waste burial when gas collection efficiencies tend to be lower.

  12. The dioxin/POPs legacy of pesticide production in Hamburg: part 2--waste deposits and remediation of Georgswerder landfill.

    PubMed

    Götz, Rainer; Sokollek, Volker; Weber, Roland

    2013-04-01

    α-HCH, β-HCH, and γ-HCH (lindane) were listed as persistent organic pollutants in the Stockholm Convention. Therefore, they need to be globally addressed including the wastes remaining from historic use and production. While at most lindane production sites the unintentionally produced 85% HCH waste isomers have been deposited, at a former pesticide factory in Hamburg-Moorfleet HCH waste isomers have been recycled from 1953 to 1984 by thermal decomposition to chlorobenzenes and resulted in high polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran (PCDD/PCDF)-contaminated residues. The management of the PCDD/PCDF-contaminated waste from the former pesticide factory in Hamburg has been assessed and quantified. Based on past accredited PCDD/PCDF measurements, the registered 3,700 tonnes of disposed thermal HCH decomposition residue contained 333 to 854 kg of PCDD/PCDF toxicity equivalent (I-TEQ) in 53-102 tonnes total sum of PCDD/PCDF. The wastes have been deposited together with other wastes in landfills in Hamburg and other parts of Germany. For the Georgswerder landfill (Hamburg), where approximately 50% of the PCDD/PCDF is disposed, current and previous situation and remediation activities are described. While PCDD/PCDF leaching from the landfill is controlled and incinerated, more water soluble organochlorines (vinyl chloride, cis-1,2-dichlorethene, chlorobenzenes) and benzene remain as a challenge for groundwater management. A comprehensive aftercare program has been established and will need to be operated by future generations including renewal of containment systems. Former lindane/HCH productions need-in addition to HCH deposits-to be assessed for possible recycling practice of HCH and related PCDD/PCDF-containing deposits. This could systematically be addressed within the Stockholm Convention implementation.

  13. Biogeochemical transformations of mercury in solid waste landfills and pathways for release.

    PubMed

    Lee, Sung-Woo; Lowry, Gregory V; Hsu-Kim, Heileen

    2016-02-01

    Mercury (Hg) is present in a variety of solid wastes including industrial wastes, household products, consumer electronics, and medical wastes, some of which can be disposed in conventional landfills. The presence of this neurotoxic metal in landfills is a concern due to the potential for it to leach or volatilize from the landfill and impact local ecosystems. The objective of this review is to describe general practices for the disposal of mercury-bearing solid wastes, summarize previous studies on the release of mercury from landfills, and delineate the expected transformations of Hg within landfill environments that would influence transport of Hg via landfill gas and leachate. A few studies have documented the emissions of Hg as landfill gas, primarily as gaseous elemental Hg(0) and smaller amounts as methylated Hg species. Much less is known regarding the release of Hg in leachate. Landfill conditions are unique from other subsurface environments in that they can contain water with very high conductivity and organic carbon concentration. Landfills also experience large changes in redox potential (and the associated microbial community) that greatly influence Hg speciation, transformations, and mobilization potential. Generally, Hg is not likely to persist in large quantities as dissolved species, since Hg(0) tends to evolve in the gas phase and divalent Hg(ii) sorbs strongly to particulate phases including organic carbon and sulfides. However, Hg(ii) has the potential to associate with or form colloidal particles that can be mobilized in porous media under high organic carbon conditions. Moreover, the anaerobic conditions within landfills can foster the growth of microorganisms that produced monomethyl- and dimethyl-Hg species, the forms of mercury with high potential for bioaccumulation. Much advancement has recently been made in the mercury biogeochemistry research field, and this study seeks to incorporate these findings for landfill settings.

  14. Biogeochemical transformations of mercury in solid waste landfills and pathways for release.

    PubMed

    Lee, Sung-Woo; Lowry, Gregory V; Hsu-Kim, Heileen

    2016-02-01

    Mercury (Hg) is present in a variety of solid wastes including industrial wastes, household products, consumer electronics, and medical wastes, some of which can be disposed in conventional landfills. The presence of this neurotoxic metal in landfills is a concern due to the potential for it to leach or volatilize from the landfill and impact local ecosystems. The objective of this review is to describe general practices for the disposal of mercury-bearing solid wastes, summarize previous studies on the release of mercury from landfills, and delineate the expected transformations of Hg within landfill environments that would influence transport of Hg via landfill gas and leachate. A few studies have documented the emissions of Hg as landfill gas, primarily as gaseous elemental Hg(0) and smaller amounts as methylated Hg species. Much less is known regarding the release of Hg in leachate. Landfill conditions are unique from other subsurface environments in that they can contain water with very high conductivity and organic carbon concentration. Landfills also experience large changes in redox potential (and the associated microbial community) that greatly influence Hg speciation, transformations, and mobilization potential. Generally, Hg is not likely to persist in large quantities as dissolved species, since Hg(0) tends to evolve in the gas phase and divalent Hg(ii) sorbs strongly to particulate phases including organic carbon and sulfides. However, Hg(ii) has the potential to associate with or form colloidal particles that can be mobilized in porous media under high organic carbon conditions. Moreover, the anaerobic conditions within landfills can foster the growth of microorganisms that produced monomethyl- and dimethyl-Hg species, the forms of mercury with high potential for bioaccumulation. Much advancement has recently been made in the mercury biogeochemistry research field, and this study seeks to incorporate these findings for landfill settings. PMID:26745831

  15. Willow growth in response to nutrients and moisture on a clay landfill cap soil. I. Growth and biomass production.

    PubMed

    Martin, Peter J; Stephens, William

    2006-02-01

    The growth and biomass production by willow (Salix viminalis L.) was studied in lysimeters containing Oxford clay landfill cap soil with different amendments, bulk densities and watering regimes. Three years from planting, stem biomass in well-watered plants was least (0.28 kg plant(-1)) with high bulk density soil (1480 kg m(-3)) and no nutritional amendment but was increased 10-fold (2.53 kg plant(-1)) by reducing soil bulk density (1200 kg m3) and adding amendments. In comparison, on a sandy loam soil it was 6.23 kg plant(-1). There were similar differences in number of stems plant(-1), stem basal area plant(-1) and plant leaf area which can be attributed to low nitrogen and phosphorus levels in Oxford clay. Water stress reduced stem biomass production by 26-37% and caused higher root:stem ratios. These were also higher on Oxford clay than on the sandy loam. Successful biomass production from willow on Oxford clay landfill caps will therefore require nutritional amendment.

  16. Landfill modelling in LCA - a contribution based on empirical data.

    PubMed

    Obersteiner, Gudrun; Binner, Erwin; Mostbauer, Peter; Salhofer, Stefan

    2007-01-01

    Landfills at various stages of development, depending on their age and location, can be found throughout Europe. The type of facilities goes from uncontrolled dumpsites to highly engineered facilities with leachate and gas management. In addition, some landfills are designed to receive untreated waste, while others can receive incineration residues (MSWI) or residues after mechanical biological treatment (MBT). Dimension, type and duration of the emissions from landfills depend on the quality of the disposed waste, the technical design, and the location of the landfill. Environmental impacts are produced by the leachate (heavy metals, organic loading), emissions into the air (CH(4), hydrocarbons, halogenated hydrocarbons) and from the energy or fuel requirements for the operation of the landfill (SO(2) and NO(x) from the production of electricity from fossil fuels). To include landfilling in an life-cycle assessment (LCA) approach entails several methodological questions (multi-input process, site-specific influence, time dependency). Additionally, no experiences are available with regard to mid-term behaviour (decades) for the relatively new types of landfill (MBT landfill, landfill for residues from MSWI). The present paper focuses on two main issues concerning modelling of landfills in LCA: Firstly, it is an acknowledged fact that emissions from landfills may prevail for a very long time, often thousands of years or longer. The choice of time frame in the LCA of landfilling may therefore clearly affect the results. Secondly, the reliability of results obtained through a life-cycle assessment depends on the availability and quality of Life Cycle Inventory (LCI) data. Therefore the choice of the general approach, using multi-input inventory tool versus empirical results, may also influence the results. In this paper the different approaches concerning time horizon and LCI will be introduced and discussed. In the application of empirical results, the presence of

  17. Perpetual landfilling through aeration of the waste mass; lessons from test cells in Georgia (USA).

    PubMed

    Read, A D; Hudgins, M; Phillips, P

    2001-01-01

    Municipal solid waste (MSW) landfills worldwide are experiencing the consequences of conventional landfilling techniques, whereby anaerobic conditions are created within the landfilled waste. Under anaerobic conditions within a landfill site slow stabilization of the waste mass occurs, producing methane, (an explosive 'green house' gas) and leachate (which can pollute groundwater) over long periods of time. As a potential solution, it was demonstrated that the aerobic degradation of MSW within a landfill can significantly increase the rate of waste decomposition and settlement, decrease the methane production and leachate leaving the system, and potentially increase the operational life of the site. Readily integrated into the existing landfill infrastructure, this approach can safely and cost-effectively convert a MSW landfill from anaerobic to aerobic degradation processes, thereby effectively composting much of the organic portions (one of the potentially polluting elements in a conventional landfill site) of the waste. This paper summarizes the successful results of two separate aerobic landfill projects located in Georgia (USA) and discusses the potential economic and environmental impacts to worldwide solid waste management practices.

  18. Greenhouse gas emissions from municipal solid waste management in Indian mega-cities: a case study of Chennai landfill sites.

    PubMed

    Jha, Arvind K; Sharma, C; Singh, Nahar; Ramesh, R; Purvaja, R; Gupta, Prabhat K

    2008-03-01

    Municipal solid waste generation rate is over-riding the population growth rate in all mega-cities in India. Greenhouse gas emission inventory from landfills of Chennai has been generated by measuring the site specific emission factors in conjunction with relevant activity data as well as using the IPCC methodologies for CH4 inventory preparation. In Chennai, emission flux ranged from 1.0 to 23.5mg CH4m(-2)h(-1), 6 to 460microg N2Om(-2)h(-1) and 39 to 906mg CO2m(2)h(-1) at Kodungaiyur and 0.9 to 433mg CH4m(-2)h(-1), 2.7 to 1200microg N2Om(-2)h(-1) and 12.3 to 964.4mg CO2m(-2)h(-1) at Perungudi. CH4 emission estimates were found to be about 0.12Gg in Chennai from municipal solid waste management for the year 2000 which is lower than the value computed using IPCC, 1996 [IPCC, 1996. Report of the 12th session of the intergovernmental panel of climate change, Mexico City, 1996] methodologies.

  19. Landfill mining: Giving garbage a second chance

    SciTech Connect

    Cobb, C.C.; Ruckstuhl, K. )

    1988-08-01

    Some communities face the problems of lack of landfill space and lack of landfill cover dirt. In some cases, existing landfills may be mined to reclaim dirt for use as cover material and to recover space for reuse. Such mining also has the potential of recovering recyclables and incinerator fuels. Machinery to reclaim refuse deposits, and their heterogeneous composted ingredients, was successfully tested at two Florida landfills in June 1987. One of the Florida mining tests, at the Collier County landfill near the city of Naples, had goals of demonstrating an economical mechanical system to separate the depository's ingredients into usable or redisposable components, and to see if the method could enable the county to avoid the expenses associated with permanent closure of a full landfill. This paper describes the history of the Collier County landfill, the equipment and feasibility test, economics, the monitoring of odors, landfill gas, and heavy metals, and results of the test.

  20. Performance evaluation of an anaerobic/aerobic landfill-based digester using yard waste for energy and compost production.

    PubMed

    Yazdani, Ramin; Barlaz, Morton A; Augenstein, Don; Kayhanian, Masoud; Tchobanoglous, George

    2012-05-01

    The objective of this study was to evaluate a new alternative for yard waste management by constructing, operating and monitoring a landfill-based two-stage batch digester (anaerobic/aerobic) with the recovery of energy and compost. The system was initially operated under anaerobic conditions for 366 days, after which the yard waste was aerated for an additional 191 days. Off gas generated from the aerobic stage was treated by biofilters. Net energy recovery was 84.3MWh, or 46kWh per million metric tons of wet waste (as received), and the biochemical methane potential of the treated waste decreased by 83% during the two-stage operation. The average removal efficiencies of volatile organic compounds and non-methane organic compounds in the biofilters were 96-99% and 68-99%, respectively.

  1. Performance evaluation of an anaerobic/aerobic landfill-based digester using yard waste for energy and compost production.

    PubMed

    Yazdani, Ramin; Barlaz, Morton A; Augenstein, Don; Kayhanian, Masoud; Tchobanoglous, George

    2012-05-01

    The objective of this study was to evaluate a new alternative for yard waste management by constructing, operating and monitoring a landfill-based two-stage batch digester (anaerobic/aerobic) with the recovery of energy and compost. The system was initially operated under anaerobic conditions for 366 days, after which the yard waste was aerated for an additional 191 days. Off gas generated from the aerobic stage was treated by biofilters. Net energy recovery was 84.3MWh, or 46kWh per million metric tons of wet waste (as received), and the biochemical methane potential of the treated waste decreased by 83% during the two-stage operation. The average removal efficiencies of volatile organic compounds and non-methane organic compounds in the biofilters were 96-99% and 68-99%, respectively. PMID:22317795

  2. Assessment of soil-gas, soil, and water contamination at the former 19th Street landfill, Fort Gordon, Georgia, 2009-2010

    USGS Publications Warehouse

    Falls, W. Fred; Caldwell, Andral W.; Guimaraes, Wladmir B.; Ratliff, W. Hagan; Wellborn, John B.; Landmeyer, James E.

    2011-01-01

    Soil gas, soil, and water were assessed for organic and inorganic constituents at the former 19th Street landfill at Fort Gordon, Georgia, from February to September 2010. Passive soil-gas samplers were analyzed to evaluate organic constituents in the hyporheic zone and flood plain of a creek and soil gas within the estimated boundaries of the former landfill. Soil and water samples were analyzed to evaluate inorganic constituents in soil samples, and organic and inorganic constituents in the surface water of a creek adjacent to the landfill, respectively. This assessment was conducted to provide environmental constituent data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. The passive soil-gas samplers deployed in the water-saturated hyporheic zone and flood plain of the creek adjacent to the former landfill indicated the presence of total petroleum hydrocarbon (TPH) and octane above method detection levels in groundwater beneath the creek bed and flood plain at all 12 soil-gas sampler locations. The TPH concentrations ranged from 51.4 to 81.4 micrograms per liter. Octane concentrations ranged from 1.78 to 2.63 micrograms per liter. These detections do not clearly identify specific source areas in the former landfill; moreover, detections of TPH and octane in a soil-gas sampler installed at a seep on the western bank of the creek indicated the potential for these constituents to be derived from source areas outside the estimated boundaries of the former landfill. A passive soil-gas sampler survey was conducted in the former landfill from June 30 to July 5, 2010, and involved 56 soil-gas samplers that were analyzed for petroleum and halogenated compounds not classified as chemical agents or explosives. The TPH soil-gas mass exceeded 2.0 micrograms in 21 samplers. Most noticeable are the two sites with TPH detections which are located in and near the hyporheic zone and are likely to affect

  3. Mill Seat Landfill Bioreactor Renewable Green Power (NY)

    SciTech Connect

    Barton & Loguidice, P.C.

    2010-01-07

    The project was implemented at the Mill Seat landfill located in the Town of Bergen, Monroe County, New York. The landfill was previously equipped with a landfill gas collection system to collect methane gas produced by the bioreactor landfill and transport it to a central location for end use. A landfill gas to energy facility was also previously constructed at the site, which utilized generator engines, designed to be powered with landfill methane gas, to produce electricity, to be utilized on site and to be sold to the utility grid. The landfill gas generation rate at the site had exceeded the capacity of the existing generators, and the excess landfill gas was therefore being burned at a candlestick flare for destruction. The funded project consisted of the procurement and installation of two (2) additional 800 KW Caterpillar 3516 generator engines, generator sets, switchgear and ancillary equipment.

  4. Waste management in the Irkutsk Region, Siberia, Russia: environmental assessment of current practice focusing on landfilling.

    PubMed

    Starostina, Vlada; Damgaard, Anders; Rechberger, Helmut; Christensen, Thomas H

    2014-05-01

    The municipal waste management system of the region of Irkutsk is described and a life cycle assessment (LCA) performed to assess the environmental performance of the system. Annually about 500 000 tons of waste are managed. The waste originates from three sources: household waste (27%), commercial waste (23%) and office & institutional waste (44%). Other waste of unknown composition constitutes 6%. Only 3% of the waste is recycled; 97% of the municipal waste is disposed of at the old Alexandrovsky landfill. The environmental impact from the current system is dominated by the landfill, which has no gas or leachate collection system. The global warming contribution is due to the emission of methane of the order of 420 000 tons CO2-equivalents per year. Collection and transport of the waste are insignificant compared with impacts from the landfill. As the old landfill runs out of capacity in a few years, the LCA modelling showed that introduction of a new and modern landfill with gas and leachate collection could improve the performance of the waste management system significantly. Collection of landfill gas and utilization for 30 years for electricity production (gas turbine) would reduce the global warming completely and result in a net saving of 100 000 CO2-equivalents per year due to storage of biogenic carbon in the landfill beyond 100 years. Considering other first-order degradation rates for the landfilled organic matter did not overtly affect the results, while assumptions about the top cover oxidation of methane significantly affected the results. This shows the importance of controlling the gas escape from the landfill.

  5. Waste management in the Irkutsk Region, Siberia, Russia: environmental assessment of current practice focusing on landfilling.

    PubMed

    Starostina, Vlada; Damgaard, Anders; Rechberger, Helmut; Christensen, Thomas H

    2014-05-01

    The municipal waste management system of the region of Irkutsk is described and a life cycle assessment (LCA) performed to assess the environmental performance of the system. Annually about 500 000 tons of waste are managed. The waste originates from three sources: household waste (27%), commercial waste (23%) and office & institutional waste (44%). Other waste of unknown composition constitutes 6%. Only 3% of the waste is recycled; 97% of the municipal waste is disposed of at the old Alexandrovsky landfill. The environmental impact from the current system is dominated by the landfill, which has no gas or leachate collection system. The global warming contribution is due to the emission of methane of the order of 420 000 tons CO2-equivalents per year. Collection and transport of the waste are insignificant compared with impacts from the landfill. As the old landfill runs out of capacity in a few years, the LCA modelling showed that introduction of a new and modern landfill with gas and leachate collection could improve the performance of the waste management system significantly. Collection of landfill gas and utilization for 30 years for electricity production (gas turbine) would reduce the global warming completely and result in a net saving of 100 000 CO2-equivalents per year due to storage of biogenic carbon in the landfill beyond 100 years. Considering other first-order degradation rates for the landfilled organic matter did not overtly affect the results, while assumptions about the top cover oxidation of methane significantly affected the results. This shows the importance of controlling the gas escape from the landfill. PMID:24692457

  6. Evaluation of methane emissions from Palermo municipal landfill: Comparison between field measurements and models

    SciTech Connect

    Di Bella, Gaetano; Di Trapani, Daniele; Viviani, Gaspare

    2011-08-15

    Methane (CH{sub 4}) diffuse emissions from Municipal Solid Waste (MSW) landfills represent one of the most important anthropogenic sources of greenhouse gas. CH{sub 4} is produced by anaerobic biodegradation of organic matter in landfilled MSW and constitutes a major component of landfill gas (LFG). Gas recovery is a suitable method to effectively control CH{sub 4} emissions from landfill sites and the quantification of CH{sub 4} emissions represents a good tool to evaluate the effectiveness of a gas recovery system in reducing LFG emissions. In particular, LFG emissions can indirectly be evaluated from mass balance equations between LFG production, recovery and oxidation in the landfill, as well as by a direct approach based on LFG emission measurements from the landfill surface. However, up to now few direct measurements of landfill CH{sub 4} diffuse emissions have been reported in the technical literature. In the present study, both modeling and direct emission measuring methodologies have been applied to the case study of Bellolampo landfill located in Palermo, Italy. The main aim of the present study was to evaluate CH{sub 4} diffuse emissions, based on direct measurements carried out with the flux accumulation chamber (static, non-stationary) method, as well as to obtain the CH{sub 4} contoured flux map of the landfill. Such emissions were compared with the estimate achieved by means of CH{sub 4} mass balance equations. The results showed that the emissions obtained by applying the flux chamber method are in good agreement with the ones derived by the application of the mass balance equation, and that the evaluated contoured flux maps represent a reliable tool to locate areas with abnormal emissions in order to optimize the gas recovery system efficiency.

  7. Changing face of the landfill

    SciTech Connect

    1995-10-01

    Integrated approach at Oregon landfill diverts wood and yard trimmings, while turning methane into power for 1,800 homes. Opened in the 1940`s as an open burn dump, Coffin Butte has evolved over the years into a sophisticated waste management facility incorporating ambitious recovery programs. While some of this change has been driven by regulatory demands, many of Valley Landfill`s innovations have come in response to market opportunities. Valley Landfill`s Processing and Recovery Center (PRC) is located a half mile down the road from the landfill site. Opened in 1990, the facility recycles urban wood waste, yard trimmings and street sweepings. The heart of this operation is a 500 hp horizontal feed, fixed-hammer grinder. Although this machine is typically used only for wood grinding, PRC was able to adapt it to handle both wood and yard trimmings by installing special feed roll assembly to compress green waste passing over the infeed belt. The facility handles approximately 40,000 cubic yards of loose green material and produces 15,000 to 18,000 yards of compost. The finished product is run through a trommel with a 5/8 inch mesh screen. Most of the compost is sold in bulk to area garden centers. A portion is processed through a 3/8 inch shaker screen and sold to a local company for use in bagged soil products. Valley Landfill is a partner in an ambitious project to generate electricity from landfill biogas.

  8. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    SciTech Connect

    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.

  9. Land application uses for dry flue gas desulfurization by-products: Phase 3

    SciTech Connect

    Dick, W.; Bigham, J.; Forster, R.; Hitzhusen, F.; Lal, R.; Stehouwer, R.; Traina, S.; Wolfe, W.; Haefner, R.; Rowe, G.

    1999-01-31

    New flue gas desulfurization (FGD) scrubbing technologies create a dry, solid by-product material consisting of excess sorbent, reaction product that contains sulfate and sulfite, and coal fly ash. Generally, dry FGD by-products are treated as solid wastes and disposed in landfills. However, landfill sites are becoming scarce and tipping fees are constantly increasing. Provided the environmental impacts are socially and scientifically acceptable, beneficial uses via recycling can provide economic benefits to both the producer and the end user of the FGD. A study titled ''Land Application Uses for Dry Flue Gas Desulfurization By-Products'' was initiated in December, 1990 to develop and demonstrate large volume, beneficial uses of FGD by-products. Phase 1 and Phase 2 reports have been published by the Electric Power Research Institute (EPRI), Palo Alto, CA. Phase 3 objectives were to demonstrate, using field studies, the beneficial uses of FGD by-products (1) as an amendment material on agricultural lands and on abandoned surface coal mine land, (2) as an engineering material for soil stabilization and raid repair, and (3) to assess the environmental and economic impacts of such beneficial uses. Application of dry FGD by-product to three soils in place of agricultural limestone increased alfalfa (Medicago sativa L.) and corn (Zea may L.) yields. No detrimental effects on soil and plant quality were observed.

  10. Engineered Municipal Waste Landfills: Climate Significance, Benefits, and some Landfill "Geophysics"

    NASA Astrophysics Data System (ADS)

    Augenstein, D.; Yazdani, R.

    2002-12-01

    Municipal Solid Waste (MSW) landfills have unique features: Wastes worldwide emit biogenic methane to the atmosphere of magnitude comparable to the total atmospheric buildup between 1980 and 1990. Carbon sequestered in landfills is large in geologic terms Management of decomposition in landfilled waste is desirable: (a) Control of waste decomposition and methane promises over tenfold cheaper greenhouse gas abatement compared to most other greenhouse gas abatement strategies. This is due in part to carbon sequestration and landfill gas energy offset of fossil fuel consumption (b) Landfill gas energy potential worldwide, is up to 1% of world energy. Use of landfill gas conserves a resource otherwise wasted (c) Monetary benefits of landfill life extension from decomposition and rapid volume reduction can be quite attractive This is a benefit for the US, where landfills are increasingly difficult and expensive to site. (d) Landfills containing mixed waste can be significant sources of atmospheric and groundwater pollutants needing control. Control is possible from advancing landfill management approaches (e) The stabilization of waste lessens pollutant risk and needs for costly long-term landfill aftercare. Greater control of landfill decomposition has been advocated in the form of "controlled" or "bioreactor" landfills. (SWANA, 1999; Reinhart and Townsend, 1996). Field trials are encouraging by several environmental/monetary criteria. Control of moisture and temperature have given fivefold or more acceleration of methane generation (Augenstein et al, 1998, 2000). There has been rapid volume loss of the landfilled waste as well, with conversion of waste organics to gas. Many trials over years have shown potential for abatement of pollutants in landfill leachate. Demonstration work by the solid waste management community attests to the benefits potential. Increasing field demonstrations, have been accompanied by observation and/or solution of several issues. As noted

  11. Producing ammonium sulfate from flue gas desulfurization by-products

    USGS Publications Warehouse

    Chou, I.-Ming; Bruinius, J.A.; Benig, V.; Chou, S.-F.J.; Carty, R.H.

    2005-01-01

    Emission control technologies using flue gas desulfurization (FGD) have been widely adopted by utilities burning high-sulfur fuels. However, these technologies require additional equipment, greater operating expenses, and increased costs for landfill disposal of the solid by-products produced. The financial burdens would be reduced if successful high-volume commercial applications of the FGD solid by-products were developed. In this study, the technical feasibility of producing ammonium sulfate from FGD residues by allowing it to react with ammonium carbonate in an aqueous solution was preliminarily assessed. Reaction temperatures of 60, 70, and 80??C and residence times of 4 and 6 hours were tested to determine the optimal conversion condition and final product evaluations. High yields (up to 83%) of ammonium sulfate with up to 99% purity were achieved under relatively mild conditions. The optimal conversion condition was observed at 60??C and a 4-hour residence time. The results of this study indicate the technical feasibility of producing ammonium sulfate fertilizer from an FGD by-product. Copyright ?? Taylor & Francis Inc.

  12. Venice Park landfill: Working with the community

    SciTech Connect

    McAdams, C.L.

    1993-09-01

    Venice Park landfill was one of the first sites to be permitted under Michigan's proposed Public Act 641. PA 641 essentially changed the rules and regulations for landfills from the simple design of digging a hole and filling it. It also upgraded standards to those that are more sophisticated, including liners, leachate collection systems, and gas extraction systems. In 1992, methane gas from the landfill was collected into wells drilled into the trash varying in depth from 30-50 feet in depth. A vacuum pulls the gas from the trash into the wells, then through a piping system. The landfill uses about 80-100 kilowatts in-house. The remainder of the gas is sold to Consumers Power Co. which uses landfill gas to supply power to homes.

  13. Quantifying Uncontrolled Air Emissions from Two Florida Landfills

    EPA Science Inventory

    Landfill gas emissions, if left uncontrolled, contribute to air toxics, climate change, trospospheric ozone, and urban smog. Measuring emissions from landfills presents unique challenges due to the large and variable source area, spatial and temporal variability of emissions, and...

  14. Characterization of uncertainty in estimation of methane collection from select U.S. landfills.

    PubMed

    Wang, Xiaoming; Nagpure, Ajay S; DeCarolis, Joseph F; Barlaz, Morton A

    2015-02-01

    Methane is a potent greenhouse gas generated from the anaerobic decomposition of waste in landfills. If captured, methane can be beneficially used to generate electricity. To inventory emissions and assist the landfill industry with energy recovery projects, the U.S. EPA developed the Landfill Gas Emissions Model (LandGEM) that includes two key parameters: the first-order decay rate (k) and methane production potential (L0). By using data from 11 U.S. landfills, Monte Carlo simulations were performed to quantify the effect of uncertainty in gas collection efficiency and municipal solid waste fraction on optimal k values and collectable methane. A dual-phase model and associated parameters were also developed to evaluate its performance relative to a single-phase model (SPM) similar to LandGEM. The SPM is shown to give lower error in estimating methane collection, with site-specific best-fit k values. Most of the optimal k values are notably greater than the U.S. EPA's default of 0.04 yr(-1), which implies that the gas generation decreases more rapidly than predicted at the current default. We translated the uncertainty in collectable methane into uncertainty in engine requirements and potential economic losses to demonstrate the practical significance to landfill operators. The results indicate that landfill operators could overpay for engine capacity by $30,000-780,000 based on overestimates of collectable methane.

  15. Life-cycle inventory and impact evaluation of mining municipal solid waste landfills.

    PubMed

    Jain, Pradeep; Powell, Jon T; Smith, Justin L; Townsend, Timothy G; Tolaymat, Thabet

    2014-01-01

    Recent research and policy directives have emerged with a focus on sustainable management of waste materials, and the mining of old landfills represents an opportunity to meet sustainability goals by reducing the release of liquid- and gas-phase contaminants into the environment, recovering land for more productive use, and recovering energy from the landfilled materials. The emissions associated with the landfill mining process (waste excavation, screening, and on-site transportation) were inventoried on the basis of diesel fuel consumption data from two full-scale mining projects (1.3-1.5 L/in-place m(3) of landfill space mined) and unit emissions (mass per liter of diesel consumption) from heavy equipment typically deployed for mining landfills. An analytical framework was developed and used in an assessment of the life-cycle environmental impacts of a few end-use management options for materials deposited and mined from an unlined landfill. The results showed that substantial greenhouse gas emission reductions can be realized in both the waste relocation and materials and energy recovery scenarios compared to a "do nothing" case. The recovery of metal components from landfilled waste was found to have the greatest benefit across nearly all impact categories evaluated, while emissions associated with heavy equipment to mine the waste itself were found to be negligible compared to the benefits that mining provided.

  16. Life-cycle inventory and impact evaluation of mining municipal solid waste landfills.

    PubMed

    Jain, Pradeep; Powell, Jon T; Smith, Justin L; Townsend, Timothy G; Tolaymat, Thabet

    2014-01-01

    Recent research and policy directives have emerged with a focus on sustainable management of waste materials, and the mining of old landfills represents an opportunity to meet sustainability goals by reducing the release of liquid- and gas-phase contaminants into the environment, recovering land for more productive use, and recovering energy from the landfilled materials. The emissions associated with the landfill mining process (waste excavation, screening, and on-site transportation) were inventoried on the basis of diesel fuel consumption data from two full-scale mining projects (1.3-1.5 L/in-place m(3) of landfill space mined) and unit emissions (mass per liter of diesel consumption) from heavy equipment typically deployed for mining landfills. An analytical framework was developed and used in an assessment of the life-cycle environmental impacts of a few end-use management options for materials deposited and mined from an unlined landfill. The results showed that substantial greenhouse gas emission reductions can be realized in both the waste relocation and materials and energy recovery scenarios compared to a "do nothing" case. The recovery of metal components from landfilled waste was found to have the greatest benefit across nearly all impact categories evaluated, while emissions associated with heavy equipment to mine the waste itself were found to be negligible compared to the benefits that mining provided. PMID:24512420

  17. Acceleration of aged-landfill stabilization by combining partial nitrification and leachate recirculation: a field-scale study.

    PubMed

    Chung, Jinwook; Kim, Seungjin; Baek, Seungcheon; Lee, Nam-Hoon; Park, Seongjun; Lee, Junghun; Lee, Heechang; Bae, Wookeun

    2015-03-21

    Leachate recirculation for rapid landfill stabilization can result in the accumulation of high-strength ammonium. An on-site sequencing batch reactor (SBR) was therefore, applied to oxidize the ammonium to nitrite, which was then recirculated to the landfill for denitrification to nitrogen gas. At relatively higher ammonium levels, nitrite accumulated well in the SBR; the nitrite was denitrified stably in the landfill, despite an insufficient biodegradable carbon source in the leachate. As the leachate was recirculated, the methane and carbon dioxide contents produced from the landfill fluctuated, implying that the organic acids and hydrogen produced in the acid production phase acted as the carbon source for denitrification in the landfill. Leachate recirculation combined with ex-situ partial nitrification of the leachate may enhance the biodegradation process by: (a) removing the nitrogen that is contained with the leachate, and (b) accelerating landfill stabilization, because the biodegradation efficiency of landfill waste is increased by supplying sufficient moisture and its byproducts are used as the carbon source for denitrification. In addition, partial nitrification using an SBR has advantages for complete denitrification in the landfill, since the available carbon source is in short supply in aged landfills.

  18. 17 CFR 229.1204 - (Item 1204) Oil and gas production, production prices and production costs.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... noted. Instruction 2 to Item 1204: Production of natural gas should include only marketable production of natural gas on an “as sold” basis. Production will include dry, residue, and wet gas, depending on whether liquids have been extracted before the registrant transfers title. Flared gas, injected gas,...

  19. 17 CFR 229.1204 - (Item 1204) Oil and gas production, production prices and production costs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... noted. Instruction 2 to Item 1204: Production of natural gas should include only marketable production of natural gas on an “as sold” basis. Production will include dry, residue, and wet gas, depending on whether liquids have been extracted before the registrant transfers title. Flared gas, injected gas,...

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

    PubMed

    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.

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

    PubMed

    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. PMID:26346020

  2. Seasonal greenhouse gas emissions (methane, carbon dioxide, nitrous oxide) from engineered landfills: Daily, intermediate, and final California cover soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We quantified the seasonal variability of CH4, CO2, and N2O emissions from fresh refuse and daily, intermediate, and final cover materials at two California landfills. Fresh refuse fluxes (g m-2 d-1) averaged CH4 0.053[+/-0.03], CO2 135[+/-117], and N2O 0.063[+/-0.059]. Average CH4 emissions across ...

  3. How EIA Estimates Natural Gas Production

    EIA Publications

    2004-01-01

    The Energy Information Administration (EIA) publishes estimates monthly and annually of the production of natural gas in the United States. The estimates are based on data EIA collects from gas producing states and data collected by the U. S. Minerals Management Service (MMS) in the Department of Interior. The states and MMS collect this information from producers of natural gas for various reasons, most often for revenue purposes. Because the information is not sufficiently complete or timely for inclusion in EIA's Natural Gas Monthly (NGM), EIA has developed estimation methodologies to generate monthly production estimates that are described in this document.

  4. Performance evaluation of an anaerobic/aerobic landfill-based digester using yard waste for energy and compost production

    SciTech Connect

    Yazdani, Ramin; Barlaz, Morton A.; Augenstein, Don; Kayhanian, Masoud; Tchobanoglous, George

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Biochemical methane potential decreased by 83% during the two-stage operation. Black-Right-Pointing-Pointer Net energy produced was 84.3 MWh or 46 kWh per million metric tons (Mg). Black-Right-Pointing-Pointer The average removal efficiency of volatile organic compounds (VOCs) was 96-99%. Black-Right-Pointing-Pointer The average removal efficiency of non-methane organic compounds (NMOCs) was 68-99%. Black-Right-Pointing-Pointer The two-stage batch digester proved to be simple to operate and cost-effective. - Abstract: The objective of this study was to evaluate a new alternative for yard waste management by constructing, operating and monitoring a landfill-based two-stage batch digester (anaerobic/aerobic) with the recovery of energy and compost. The system was initially operated under anaerobic conditions for 366 days, after which the yard waste was aerated for an additional 191 days. Off gas generated from the aerobic stage was treated by biofilters. Net energy recovery was 84.3 MWh, or 46 kWh per million metric tons of wet waste (as received), and the biochemical methane potential of the treated waste decreased by 83% during the two-stage operation. The average removal efficiencies of volatile organic compounds and non-methane organic compounds in the biofilters were 96-99% and 68-99%, respectively.

  5. The environmental comparison of landfilling vs. incineration of MSW accounting for waste diversion.

    PubMed

    Assamoi, Bernadette; Lawryshyn, Yuri

    2012-05-01

    This study evaluates the environmental performance and discounted costs of the incineration and landfilling of municipal solid waste that is ready for the final disposal while accounting for existing waste diversion initiatives, using the life cycle assessment (LCA) methodology. Parameters such as changing waste generation quantities, diversion rates and waste composition were also considered. Two scenarios were assessed in this study on how to treat the waste that remains after diversion. The first scenario is the status quo, where the entire residual waste was landfilled whereas in the second scenario approximately 50% of the residual waste was incinerated while the remainder is landfilled. Electricity was produced in each scenario. Data from the City of Toronto was used to undertake this study. Results showed that the waste diversion initiatives were more effective in reducing the organic portion of the waste, in turn, reducing the net electricity production of the landfill while increasing the net electricity production of the incinerator. Therefore, the scenario that incorporated incineration performed better environmentally and contributed overall to a significant reduction in greenhouse gas emissions because of the displacement of power plant emissions; however, at a noticeably higher cost. Although landfilling proves to be the better financial option, it is for the shorter term. The landfill option would require the need of a replacement landfill much sooner. The financial and environmental effects of this expenditure have yet to be considered. PMID:22099926

  6. The environmental comparison of landfilling vs. incineration of MSW accounting for waste diversion.

    PubMed

    Assamoi, Bernadette; Lawryshyn, Yuri

    2012-05-01

    This study evaluates the environmental performance and discounted costs of the incineration and landfilling of municipal solid waste that is ready for the final disposal while accounting for existing waste diversion initiatives, using the life cycle assessment (LCA) methodology. Parameters such as changing waste generation quantities, diversion rates and waste composition were also considered. Two scenarios were assessed in this study on how to treat the waste that remains after diversion. The first scenario is the status quo, where the entire residual waste was landfilled whereas in the second scenario approximately 50% of the residual waste was incinerated while the remainder is landfilled. Electricity was produced in each scenario. Data from the City of Toronto was used to undertake this study. Results showed that the waste diversion initiatives were more effective in reducing the organic portion of the waste, in turn, reducing the net electricity production of the landfill while increasing the net electricity production of the incinerator. Therefore, the scenario that incorporated incineration performed better environmentally and contributed overall to a significant reduction in greenhouse gas emissions because of the displacement of power plant emissions; however, at a noticeably higher cost. Although landfilling proves to be the better financial option, it is for the shorter term. The landfill option would require the need of a replacement landfill much sooner. The financial and environmental effects of this expenditure have yet to be considered.

  7. Investigation of greenhouse gas emissions from a landfill site and agriculture in the UK by deployment of an in-situ FTIR

    NASA Astrophysics Data System (ADS)

    Sonderfeld, Hannah; Humpage, Neil; Jeanjean, Antoine; Leigh, Roland; Allen, Grant; Boesch, Hartmut

    2016-04-01

    The main greenhouse gases (GHG) emitted by human activities in the UK are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Understanding and quantifying their emissions is essential to monitor and guide emission reduction measures. The GAUGE (Greenhouse gAs Uk and Global Emissions) project funded by NERC aims to improve the knowledge of the UK GHG budget by an extensive measurement program. In this presentation, we focus on two important sources of these GHG: Waste and agricultural sector. We are presenting data from the deployment of an in-situ FTIR (Ecotech) for continuous and simultaneous sampling of CO2, CH4, N2O and CO with a high time resolution in the order of minutes. During a two week field campaign at a landfill site near Ipswich in August 2014, measurements were taken within a radius of 320 m of the uncovered and active area of the landfill, which was still filled with new incoming waste. The data are analysed in detail for emission ratios of CH4 to CO2. Thereby a consistent ratio in favour of CO2 is found for these emissions. We have applied a computation fluid dynamics (CFD) model, constrained with local wind measurements and a detailed topographic map of the landfill site, to the in-situ concentration data to calculate emission fluxes of the active site. Since October 2014 the FTIR has been sampling from a church tower in Glatton as part of a near surface sampling network in East Anglia focusing on regional GHG emissions from agriculture. The site is mainly influenced by south westerly winds. A clear diurnal cycle is observed in summer for CO2, CH4 and N2O, which is less pronounced in the winter months. A simulation of the methane and nitrous oxide concentrations through application of the NAME model to the EDGAR and NAEI emission inventories illustrates some shortcomings in the available emission inventories for the probed region.

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

    NASA Astrophysics Data System (ADS)

    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.

  9. ConocoPhillips Gas Hydrate Production Test

    SciTech Connect

    Schoderbek, David; Farrell, Helen; Howard, James; Raterman, Kevin; Silpngarmlert, Suntichai; Martin, Kenneth; Smith, Bruce; Klein, Perry

    2013-06-30

    Work began on the ConocoPhillips Gas Hydrates Production Test (DOE award number DE-NT0006553) on October 1, 2008. This final report summarizes the entire project from January 1, 2011 to June 30, 2013.

  10. Thermal treatment of landfill leachate and the emission control.

    PubMed

    Atabarut, Tamer; Ekinci, Ekrem

    2006-01-01

    The main aim of this study was to develop an appropriate system for the thermal treatment of landfill leachate. In the initial phase of this study, characterization studies were conducted both for the waste disposed and leachate generated. For the thermal treatment of the landfill leachate two different incineration systems, namely a double-phase liquid waste incineration system and a new pilot-scale incineration system, were tested. During the experimental study, the capability of the new pilot-scale incineration system was proven to treat the landfill leachate. However, high concentrations of NOx were recorded. On the other hand, the experimental data, obtained during the testing period of the double-phase liquid waste incineration system, indicated that the fluidized bed incinerator provided an extra unit sufficient to complete the oxidation of partial products of combustion and organics carried from the initial incinerator. Therefore, lower gaseous emissions were noted. However, an agglomeration problem has occurred, due to the high concentrations of Na, Ca and K. It was concluded that considering the flexibility of the thermal processes, thermal treatment of leachate could successfully be applied to Odayeri landfill, as well as to many landfills, if proper gas treatment systems are applied.

  11. In situ denitrification in controlled landfill systems

    SciTech Connect

    Onay, T.T.; Pohland, F.G.

    1996-11-01

    The characteristics of leachate from landfill disposal sites vary according to the operational stage of the landfill. Leachates from old landfills are often rich in ammonia nitrogen due to the hydrolysis and fermentation of nitrogenous fractions of biodegradable refuse substrates. The relative concentration accumulating as stabilization progresses is also influenced by washout as leachate is collected and removed for external treatment. However, in landfills operated as bioreactors with leachate containment, collection and in situ recirculation to accelerate decomposition of readily available organic fractions of the refuse, leachate ammonia nitrogen concentrations may accumulate to much higher levels. High leachate ammonia nitrogen concentrations in landfill leachate have been reported, resulting in separate treatment challenges if direct discharge to either land or receiving waters is practiced. External treatment options for landfill leachate may involve complex physical-chemical and/or biological processes for removal of both high-strength organic and inorganic fractions, including nitrogen. Such separate leachate treatment systems are often costly and difficult to control on a continuum. Therefore, this study focused on the investigation of landfill ammonia nitrogen generation patterns, and the potential for its in situ attenuation and conversion in landfills constructed to permit sequential nitrification and denitrification using leachate recirculation. Accordingly, the landfill is constructed and operated as a controlled bioreactor system, with opportunity to convert ammonia to nitrate by nitrification and nitrate to nitrogen gas by denitrification. The results presented in this paper focus on in situ landfill denitrification of nitrified ammonia.

  12. Did state renewable portfolio standards induce technical change in methane mitigation in the U.S. landfill sector?

    NASA Astrophysics Data System (ADS)

    Delhotal, Katherine Casey

    Landfill gas (LFG) projects use the gas created from decomposing waste, which is approximately 49% methane, and substitute it for natural gas in engines, boilers, turbines, and other technologies to produce energy or heat. The projects are beneficial in terms of increased safety at the landfill, production of a cost-effective source of energy or heat, reduced odor, reduced air pollution emissions, and reduced greenhouse gas emissions. However, landfills sometimes face conflicting policy incentives. The theory of technical change shows that the diffusion of a technology or groups of technologies increases slowly in the beginning and then picks up speed as knowledge and better understanding of using the technology diffuses among potential users. Using duration analysis, data on energy prices, State and Federal policies related to landfill gas, renewable energy, and air pollution, as well as control data on landfill characteristics, I estimate the influence and direction of influence of renewable portfolio standards (RPS). The analysis found that RPS positively influences the diffusion of landfill gas technologies, encouraging landfills to consider electricity generation projects over direct sales of LFG to another facility. Energy price increases or increased revenues for a project are also critical. Barriers to diffusion include air emission permits in non-attainment areas and policies, such as net metering, which promote other renewables over LFG projects. Using the estimates from the diffusion equations, I analyze the potential influence of a Federal RPS as well as the potential interaction with a Federal, market based climate change policy, which will increase the revenue of a project through higher energy sale prices. My analysis shows that a market based climate change policy such as a cap-and-trade or carbon tax scheme would increase the number of landfill gas projects significantly more than a Federal RPS.

  13. Livingston Parish Landfill Methane Recovery Project (Feasibility Study)

    SciTech Connect

    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

  14. Chlorination decomposition of struvite and recycling of its product for the removal of ammonium-nitrogen from landfill leachate.

    PubMed

    Huang, Haiming; Huang, Lingyun; Zhang, Qingrui; Jiang, Yang; Ding, Li

    2015-10-01

    Struvite (MgNH4PO4⋅6H2O) precipitation is a promising method for ammonium (NH4(+)) removal from the wastewater. However, the high cost incurred with the use of magnesium and phosphate sources hinders the successful application of this method. This paper presents a novel recycling technology of struvite that is based on the chlorination decomposition of struvite. The study results indicated that struvite can be effectively decomposed by sodium hypochlorite and that the solid/liquid ratio of struvite in solution did not affect the ammonium-nitrogen (NH4-N) decomposition efficiency of struvite. Through the analysis of the reaction process, the mechanism of struvite decomposition was proposed to be simultaneous dissolution and oxidation of struvite, and the main component of the decomposition product generated was determined to be newberyite, dissolved HPO4(2-) and Mg(2+), and magnesium phosphate. When the decomposition product was recycled, its pH had to be adjusted for high NH4-N removal. NH4-N of 92% could be removed from landfill leachate when the decomposition product solution pH before recycling was adjusted to 3 and the precipitation pH was maintained at 9. A five-cycle recycling process showed that recycling of struvite chlorination decomposition product was a highly efficient and sustainable method for the removal of NH4-N. An economic evaluation showed that the use of recycled struvite for the five-process cycles by the proposed process could save the cost of chemicals by approximately 34% as compared to the use of pure chemicals.

  15. RADIOLYTIC GAS PRODUCTION RATES OF POLYMERS EXPOSED TO TRITIUM GAS

    SciTech Connect

    Clark, E.

    2013-08-31

    Data from previous reports on studies of polymers exposed to tritium gas is further analyzed to estimate rates of radiolytic gas production. Also, graphs of gas release during tritium exposure from ultrahigh molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, a trade name is Teflon®), and Vespel® polyimide are re-plotted as moles of gas as a function of time, which is consistent with a later study of tritium effects on various formulations of the elastomer ethylene-propylene-diene monomer (EPDM). These gas production rate estimates may be useful while considering using these polymers in tritium processing systems. These rates are valid at least for the longest exposure times for each material, two years for UHMW-PE, PTFE, and Vespel®, and fourteen months for filled and unfilled EPDM. Note that the production “rate” for Vespel® is a quantity of H{sub 2} produced during a single exposure to tritium, independent of length of time. The larger production rate per unit mass for unfilled EPDM results from the lack of filler- the carbon black in filled EPDM does not produce H{sub 2} or HT. This is one aspect of how inert fillers reduce the effects of ionizing radiation on polymers.

  16. Fluxes of methane between landfills and the atmosphere: Natural and engineered controls

    SciTech Connect

    Bogner, J.; Meadows, M.; Czepiel, P.

    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.

  17. Evolution of gas saturation and relative permeability during gas production from hydrate-bearing sediments: Gas invasion vs. gas nucleation

    NASA Astrophysics Data System (ADS)

    Jang, Jaewon; Santamarina, J. Carlos

    2014-01-01

    Capillarity and both gas and water permeabilities change as a function of gas saturation. Typical trends established in the discipline of unsaturated soil behavior are used when simulating gas production from hydrate-bearing sediments. However, the evolution of gas saturation and water drainage in gas invasion (i.e., classical soil behavior) and gas nucleation (i.e., gas production) is inherently different: micromodel experimental results show that gas invasion forms a continuous flow path while gas nucleation forms isolated gas clusters. Complementary simulations conducted using tube networks explore the implications of the two different desaturation processes. In spite of their distinct morphological differences in fluid displacement, numerical results show that the computed capillarity-saturation curves are very similar in gas invasion and nucleation (the gas-water interface confronts similar pore throat size distribution in both cases); the relative water permeability trends are similar (the mean free path for water flow is not affected by the topology of the gas phase); and the relative gas permeability is slightly lower in nucleation (delayed percolation of initially isolated gas-filled pores that do not contribute to gas conductivity). Models developed for unsaturated sediments can be used for reservoir simulation in the context of gas production from hydrate-bearing sediments, with minor adjustments to accommodate a lower gas invasion pressure Po and a higher gas percolation threshold.

  18. Stable isotopic signatures (δ13C, δD) of methane from European landfill sites

    NASA Astrophysics Data System (ADS)

    Bergamaschi, P.; Lubina, C.; KöNigstedt, R.; Fischer, H.; Veltkamp, A. C.; Zwaagstra, O.

    1998-04-01

    The stable isotopic signatures (δ13C, δD) of CH4 from four German and Dutch landfill sites have been characterized using different techniques for isotope analysis (tunable diode laser absorption spectroscopy and isotope ratio mass spectrometry). Samples taken directly from the gas collection systems show fairly uniform, biogenic δ13C-δD isotopic signatures [δ13C = (-59.0±2.2)‰ VPDB (n = 104); δD = (-304±10)‰ VSMOW (n = 46)]. In contrast, emission samples taken with static chambers on soil-covered landfill areas exhibit a considerable δ13C-δD variability, mainly due to the influence of aerobic bacterial CH4 oxidation, which occurs when the biogas CH4 encounters atmospheric oxygen available in the uppermost region of the cover soil. Soil gas samples from the landfill covers clearly show the progressive isotopic enrichment within the aerobic regions of the soil. Isotope fractionation factors due to CH4 oxidation were determined to be α(δ13C) = 1.008±0.004 and α(δD) = 1.039±0.026. On average, about 80% (70-97%) of CH4 is oxidized during the transport through cover soils, while no significant CH4 oxidation was found in uncovered areas consisting of freshly dumped waste. Area-integrated δ13C values of total emissions were derived from upwind-downwind measurements around the landfill and show very little temporal and site-to-site variation (δ13C = (-55.4±1.4)‰ VPDB (n = 13; four different landfills)). CH4 budgets were established for two landfill sites, indicating that projected CH4 surface emissions from uncovered and covered areas are significantly lower compared to total CH4 production (for a landfill without gas collection) or compared to the difference between CH4 production and recovery (for a landfill with a gas collection system). For these two landfill sites the overall fraction of CH4 oxidation is estimated to be 46 and 39% (53%) of total CH4 production (minus recovery). Furthermore, the δ13C balance (comparing the δ13C values of the

  19. Geochemical and VOC-constraints on landfill gas age and attenuation characteristics: A case study from a waste disposal facility in Southern California.

    PubMed

    Hagedorn, Benjamin; Kerfoot, Henry B; Verwiel, Mark; Matlock, Bruce

    2016-07-01

    In this study, a multi-tracer approach was applied to a complex, methane-impacted site in Southern California to (1) distinguish between natural gas and landfill gas (LFG)-derived methane impacts at site perimeter gas probes, (2) estimate the relative age of the LFG at these probes, and (3) document natural attenuation trends during a 3-year monitoring period. Relationships between methane and ethane values suggest that at the majority of probes, methane is from LFG and not from natural gas and that the relative contribution of LFG methane at these probes has increased over the monitoring period. To evaluate whether LFG is attenuating in the subsurface, the relative age of LFG was estimated by comparing readily degraded VOCs that are major constituents in LFG (toluene in this case) with those resistant to degradation (Freons). Time-series data trends are consistent with several probes being impacted by fresh LFG from recent releases that occurred after the update of the local LFG collection and control system (LFGCCS). Data further indicate some probes to be only affected by legacy LFG from a past release that occurred prior to the LFGCCS update and that, because of a lack of oxygen in the subsurface, had not been fully degraded. The outlined attenuation evaluation methodology is potentially applicable to other sites or even groundwater contaminants; however, the assessment is limited by the degree of homogeneity of the LFG source composition and non-LFG-derived toluene inputs to the analyzed samples. PMID:26601889

  20. [Pathways of mercury emissions to atmosphere from closed municipal landfills].

    PubMed

    Li, Zhong-Gen; Feng, Xin-Bin; Tang, Shun-Lin; Wang, Shao-Feng

    2006-01-01

    Using the automated mercury vapor analyzer and dynamic flux chamber (DFC) method, the pathways of mercury emissions to atmosphere were measured at a closed landfill in Wuhan, China. The results show that the mainly pathway is by the surface cover, and emissions from vent pipes is negligible. Average Hg fluxes during the observation period was (192.5 +/- 245.3) ng x (m2 x h)(-1), which was 1 - 2 orders of magnitude greater than that from background zone. Hg flux exhibited a clearly diurnal pattern, reaching the maximum near midday and the lowest during night. Solar radiation was the environmental factor that has highest relationship with Hg flux, with coefficient of 0.77, this indicated that photo-reduction of Hg(II) being a prominent process in the production of volatile elemental mercury (Hg(0)). Mercury concentrations in landfill gas (LFG) at different vent pipes averaged from 7.0 - 68.9 ng x m(-3), which was much lower than that of operational landfills, and the flow rate of landfill gas was very slow.

  1. Beneficial uses of recycled asphalt-stabilized products as landfill cover and capping systems

    SciTech Connect

    Camougis, G.

    1996-12-31

    The American Reclamation Corporation (AMREC{reg_sign}) has played a major role in the development of new programs for the recycling of discarded materials from construction, demolition, remediation and manufacturing operations. Excavated petroleum-contaminated soils (oily soils), asphalt paving, concrete rubble, and discarded asphalt roofing shingles have been processed and recycled into beneficially useful construction products. AMREC uses a cold-mix, asphalt-emulsion technology to process many of the recyclables received at its recycling facility in Charlton, MA. Recyclable materials are processed and blended to produce recycled, asphalt-stabilized products. In addition, recycled, asphalt-stabilized products are being investigated and tested for other beneficial uses. This includes their uses as capping materials and as containment materials.

  2. Release and fate of fluorocarbons in a shredder residue landfill cell: 2. Field investigations.

    PubMed

    Scheutz, Charlotte; Fredenslund, Anders M; Nedenskov, Jonas; Kjeldsen, Peter

    2010-11-01

    The shredder residues from automobiles, home appliances and other metal containing products are often disposed in landfills, as recycling technologies for these materials are not common in many countries. Shredder waste contains rigid and soft foams from cushions and insulation panels blown with fluorocarbons. The objective of this study was to determine the gas composition, attenuation, and emission of fluorocarbons in a monofill shredder residue landfill cell by field investigation. Landfill gas generated within the shredder waste primarily consisted of CH(4) (27%) and N(2) (71%), without CO(2), indicating that the gas composition was governed by chemical reactions in combination with anaerobic microbial reactions. The gas generated also contained different fluorocarbons (up to 27 μg L(-1)). The presence of HCFC-21 and HCFC-31 indicated that anaerobic degradation of CFC-11 occurred in the landfill cell, as neither of these compounds has been produced for industrial applications. This study demonstrates that a landfill cell containing shredder waste has a potential for attenuating CFC-11 released from polyurethane (PUR) insulation foam in the cell via aerobic and anaerobic biodegradation processes. In deeper, anaerobic zones of the cell, reductive dechlorination of CFCs to HCFCs was evident, while in the shallow, oxic zones, there was a high potential for biooxidation of both methane and lesser chlorinated fluorocarbons. These findings correlated well with both laboratory results (presented in a companion paper) and surface emission measurements that, with the exception from a few hot spots, indicated that surface emissions were negative or below detection. PMID:20444588

  3. Antrim gas play, production expanding in Michigan

    SciTech Connect

    Not Available

    1994-05-30

    Devonian Antrim shale gas, the Michigan basin's dominant hydrocarbon play in terms of number of wells drilled for several years, shows every sign of continuing at a busy pace. About 3,500 Antrim completions now yield 350 MMcfd, more than 60% of Michigan's gas production. The outlook is for Antrim production to climb in the next 2--3 years to 500--600 MMcfd, about 1% of US gas output. These delivery numbers, slow decline rates, and expected producing life of 20--30 years has snagged pipelines attention. The growing production overtaxed local gathering facilities last fall, and the play recently got its first interstate outlet. Completion and production technology advances are improving well performance and trimming costs. Several hundred wells a year are likely to be drilled during the next few years. Production increases are coming from new wells, deepenings, and workovers. Numerous pipeline/gathering projects are planned in the area to handle the growing Antrim volumes. The paper discusses the development of this resource, efforts to extend the play, geology and production, drilling programs, and gas transportation.

  4. Heat management strategies for MSW landfills.

    PubMed

    Yeşiller, Nazli; Hanson, James L; Kopp, Kevin B; Yee, Emma H

    2016-10-01

    Heat is a primary byproduct of landfilling of municipal solid waste. Long-term elevated temperatures have been reported for MSW landfills under different operational conditions and climatic regions around the world. A conceptual framework is presented for management of the heat generated in MSW landfills. Three main strategies are outlined: extraction, regulation, and supplementation. Heat extraction allows for beneficial use of the excess landfill heat as an alternative energy source. Two approaches are provided for the extraction strategy: extracting all of the excess heat above baseline equilibrium conditions in a landfill and extracting only a part of the excess heat above equilibrium conditions to obtain target optimum waste temperatures for maximum gas generation. Heat regulation allows for controlling the waste temperatures to achieve uniform distribution at target levels at a landfill facility. Two approaches are provided for the regulation strategy: redistributing the excess heat across a landfill to obtain uniform target optimum waste temperatures for maximum gas generation and redistributing the excess heat across a landfill to obtain specific target temperatures. Heat supplementation allows for controlling heat generation using external thermal energy sources to achieve target waste temperatures. Two approaches are provided for the supplementation strategy: adding heat to the waste mass using an external energy source to increase waste temperatures and cooling the waste mass using an external energy source to decrease waste temperatures. For all strategies, available landfill heat energy is determined based on the difference between the waste temperatures and the target temperatures. Example analyses using data from landfill facilities with relatively low and high heat generation indicated thermal energy in the range of -48.4 to 72.4MJ/m(3) available for heat management. Further modeling and experimental analyses are needed to verify the effectiveness

  5. Hazardous waste landfill leachate characteristics

    SciTech Connect

    Pavelka, C. ); Loehr, R.C. . Environmental and Water Resources Engineering Program); Haikola, B. )

    1993-01-01

    Leachate data from 18 commercial hazardous waste landfills or cells were evaluated to determine overall leachate characteristics and parameters that may affect leachate generation and characteristics. The landfills studied have a wide range of practices, none of which are necessarily representative of the most current landfill design, operating or closure practice in the United States. The leachate samples were from landfills that represented varying waste types, waste age, geographic locations and climate. The parameters evaluated included chemical properties, co-disposal of hazardous and municipal solid wastes, climatic conditions, and waste age in the landfills. The leachate samples had been analyzed for 62 volatiles, 107 semi-volatiles, 16 metals, 28 pesticides, herbicides and insecticides, and 17 other chemicals. The results indicate that: (a) the organics in the leachate with high concentrations had high solubilities and low octanol-water coefficients, (b) landfills in arid climates produced less leachate than those in temperate and sub-tropical climates, and (c) leachate production appeared to be related to use of a cap or cover.

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

    EPA Science Inventory

    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...

  7. Occurrence and ecological potential of pharmaceuticals and personal care products in groundwater and reservoirs in the vicinity of municipal landfills in China.

    PubMed

    Peng, Xianzhi; Ou, Weihui; Wang, Chunwei; Wang, Zhifang; Huang, Qiuxin; Jin, Jiabin; Tan, Jianhua

    2014-08-15

    Pharmaceutical and personal care products (PPCPs), including antibiotics, azole anti-fungals, non-steroid anti-inflammatory drugs, lipid regulators, parabens, antiseptics, and bisphenol A, were investigated in groundwater and reservoirs in the vicinity of two municipal landfills in the metropolis of Guangzhou, South China. Dehydroerythromycin, sulfamethoxazole, fluconazole, salicylic acid, methylparaben, triclosan, and bisphenol A were the mostly frequently detected PPCPs in the groundwater at low ng L(-1) levels. In the reservoirs, the PPCPs were widely detected at higher frequencies and concentrations, especially sulfamethoxazole, propiconazole, and ibuprofen, with maximal concentrations above 1 μg L(-1). The PPCPs in the groundwater did not show significant seasonal differences or spatial trends. However, in the reservoirs, higher PPCP concentrations were observed in spring than in other seasons. The anti-bacterials in the groundwater posed medium risks to algae. In the reservoirs, the sulfonamides and macrolides posed low to high risks, while ibuprofen, salicylic acid, and clofibric acid presented low to medium risks to aquatic organisms. Overall, the results showed that the PPCP contaminants and subsequent ecological risks in the groundwater and surface water in the vicinity of the landfills may be of serious concern. More research is needed to better correlate the landfill leachates and PPCP contamination in the nearby aquatic environments.

  8. Tracy Gas field, new shallow production

    SciTech Connect

    Sterling, R.; Nahama, R. )

    1991-02-01

    The Tracy Gas field was the first commercial gas production in California. Amerada Hess found production in the Cretaceous Tracy Formation in 1934. Five production wells ultimately produced 13 BCF by 1959. In 1989, Nahama and Weagant Energy Company (NWEC) purchased seismic data acquired by Shell Oil in 1980. The data was reprocessed for amplitude vs. offset (AVO) analysis. The data showed a bright spot at 1.0 section that exhibit an AVO response indicative of the presence of gas. Log data suggested the possibility of gas in the based Miocene Zilch Sands in the Amerada F.D.L. {number sign}4 well drilled in Sec. 15. T2S, R5E drilled in 1934. Husky Oil found gas production in the Zilch with the Rossi {number sign}1 well drilled in 1980. The most obvious problem with following up Husky's well was the J. M. Young Cordoza {number sign}1, a dry hole, that was misplotted on all of the commercially available base maps. Nahama and Weagant Energy Company drilled the Tracy 1-15 well in January 1990 directionally to test the Zilch sands in Sec. 15 almost exactly where the dry hole had been misplotted, resulting in a discovery of 48 net ft of pay in the Zilch. The Miocene gas is present in basal Zilch sands that were deposited unconformably on the Cretaceous Blewett Formation. The gas is located on the west flank of the Tracy anticline which is formed by a 90{degree} bend in the Vernalis fault, a thrust fault with over 1,600 ft of vertical movement. The Vernalis fault had movement as recently as the Pliocene, based on seismic data. Due to the relative youth of the fault, deeper potential in the Winters and Lathrop formations is believed not to exist on the Tracy anticline.

  9. Tracking quicksilver: estimation of mercury waste from consumer products and subsequent verification by analysis of soil, water, sediment, and plant samples from the Cebu City, Philippines, landfill.

    PubMed

    Buagas, Dale Jo B; Megraso, Cristi Cesar F; Namata, John Darwin O; Lim, Patrick John Y; Gatus, Karen P; Cañete, Aloysius M L

    2015-03-01

    Source attribution of mercury (Hg) is critical for policy development to minimize the impact of Hg in wastes. Mercury content of consumer products and its subsequent release into the waste stream of Cebu City, Philippines, is estimated through surveys that employed validated, enumerator-administered questionnaires. Initially, a citywide survey (n = 1636) indicates that each household annually generates 1.07 ppm Hg (i.e., mg Hg/kg waste) and that linear and compact fluorescent lamps (17.2 %) and thermometers (52.1 %) are the major sources of Hg. A subsequent survey (n = 372) in the vicinity of the city's municipal solid waste landfill shows that residents in the area annually generate 0.38 ppm Hg per household, which is less than the citywide mean; surprisingly though, less affluent respondents living closer to the landfill site reported more Hg from thermometers and sphygmomanometers. Analysis of collected soil (0.238 ppm), leachate water (6.5 ppb), sediment (0.109 ppm), and three plants (0.393 to 0.695 ppm) shows no significant variation throughout five stations in and around the landfill site, although the period of collection is significant for soil (P = 0.001) and Cenchrus echinatus (P = 0.016). Detected Hg in the landfill is considerably less than the annual estimated release, indicating that there is minimal accumulation of Hg in the soil or in plants. As a result of this project, a policy brief has been provided to the Cebu City council in aid of hazardous waste legislation.

  10. The Application Of Biofilter System For Reduction Of Methane Emissions From Modern Sanitary Landfills

    NASA Astrophysics Data System (ADS)

    Sung, K.; Park, S.

    2007-12-01

    Increased atmospheric concentrations of greenhouse gases (GHG) caused by anthropogenic activities has been related to global climate change. Methane, the second most important GHG after CO2, is 21 times more effective at trapping heat than CO2. Therefore, methane emission control is of utmost importance for global warming reduction. To minimize leachate production and protect groundwater resources, modern sanitary landfills are equipped with composite covers and gas collection systems. Methane from modern sanitary landfills is vented directly to the atmosphere, except for some of the largest landfills where it is recovered as energy and burned at the site. However, the efficiency of energy recovery systems in larger landfills is reduced as the amount of CH4 generated from landfill begins to decrease. In this study, the performance of a lab-scale model biofilter system was investigated to treat CH4 gas emitted from modern sanitary landfills by conducting batch and column experiments using landfill cover soil amended with earthworm cast as the filter bed medium. From the batch experiments to measure the influence of moisture content and temperature of the filter medium on CH4 removal capacity of a biofilter system, the optimum moisture content and temperature were found to be 10-15% by weight and 25-35°C, respectively. The column experiment was conducted to measure the influence of inlet CH4 concentration and CH4 loading rate on CH4 removal capacity of a biofilter system. As the inlet CH4 concentration decreased, the percentage of CH4 oxidized increased. Up to a CH4 loading rate of 2785 g CH4 m3 h- 1 (EBRT = 7.7 min), the CH4 removal efficiency of the biofilter was able to reach 100%. Based on the results of the study, the installation of a properly managed biofilter system should be capable of achieving a reduction in atmospheric CH4 emissions from modern sanitary landfills at low CH4 generation stage.

  11. Interconnecting compressors control coalbed gas production

    SciTech Connect

    Payton, R.; Niederhofer, J. )

    1992-10-05

    This paper reports that centralized compressors afford Taurus Exploration Inc.'s coalbed gas operations optimum control of gas production. Unlike satellite stations, the centralized system allows methane gas to e shifted from station to station via the interconnecting low-pressure pipeline network. The operations area encompasses approximately 40,000 acres, about 40 miles southwest of Birmingham, Ala. The project includes about 250-miles of low-pressure gas flow lines to almost 400 wells. The centralized system is less costly than a satellite station to build and operate. Unlike a satellite station that requires each compressor to have a complete set of ancillary equipment, the centralized system requires only one suction manifold, one dehydration setup, and one metering facility for every five compressor sets.

  12. Bio-gas production from alligator weeds

    NASA Technical Reports Server (NTRS)

    Latif, A.

    1976-01-01

    Laboratory experiments were conducted to study the effect of temperature, sample preparation, reducing agents, light intensity and pH of the media, on bio-gas and methane production from the microbial anaerobic decomposition of alligator weeds (Alternanthera philoxeroides. Efforts were also made for the isolation and characterization of the methanogenic bacteria.

  13. New Methodology for Natural Gas Production Estimates

    EIA Publications

    2010-01-01

    A new methodology is implemented with the monthly natural gas production estimates from the EIA-914 survey this month. The estimates, to be released April 29, 2010, include revisions for all of 2009. The fundamental changes in the new process include the timeliness of the historical data used for estimation and the frequency of sample updates, both of which are improved.

  14. The environmental comparison of landfilling vs. incineration of MSW accounting for waste diversion

    SciTech Connect

    Assamoi, Bernadette; Lawryshyn, Yuri

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Residential waste diversion initiatives are more successful with organic waste. Black-Right-Pointing-Pointer Using a incineration to manage part of the waste is better environmentally. Black-Right-Pointing-Pointer Incineration leads to more power plant emission offsets. Black-Right-Pointing-Pointer Landfilling all of the waste would be preferred financially. - Abstract: This study evaluates the environmental performance and discounted costs of the incineration and landfilling of municipal solid waste that is ready for the final disposal while accounting for existing waste diversion initiatives, using the life cycle assessment (LCA) methodology. Parameters such as changing waste generation quantities, diversion rates and waste composition were also considered. Two scenarios were assessed in this study on how to treat the waste that remains after diversion. The first scenario is the status quo, where the entire residual waste was landfilled whereas in the second scenario approximately 50% of the residual waste was incinerated while the remainder is landfilled. Electricity was produced in each scenario. Data from the City of Toronto was used to undertake this study. Results showed that the waste diversion initiatives were more effective in reducing the organic portion of the waste, in turn, reducing the net electricity production of the landfill while increasing the net electricity production of the incinerator. Therefore, the scenario that incorporated incineration performed better environmentally and contributed overall to a significant reduction in greenhouse gas emissions because of the displacement of power plant emissions; however, at a noticeably higher cost. Although landfilling proves to be the better financial option, it is for the shorter term. The landfill option would require the need of a replacement landfill much sooner. The financial and environmental effects of this expenditure have yet to be considered.

  15. Separation of flue-gas scrubber sludge into marketable products

    SciTech Connect

    Kawatra, S.K.; Eisele, T.C.

    1997-08-31

    A tremendous amount of wet flue-gas desulfurization scrubber sludge (estimated 20 million metric tons per year in the US) is currently being landfilled at a huge cost to utility companies. Scrubber sludge is the solid precipitate produced during desulfurization of flue-gas from burning high sulfur coal. The amount of this sludge is expected to increase in the near future due to ever increasing governmental regulation concerning the amount of sulfur emissions. Scrubber sludge is a fine, grey colored powder that contains calcium sulfite hemihydrate (CaSO{sub 3} {center_dot} 1/2H{sub 2}), calcium sulfate dihydrate (CaSO{sub 4} {center_dot} 2H{sub 2}O), limestone (CaCO{sub 3}), silicates, and iron oxides. This material can continue to be landfilled at a steadily increasing cost, or an alternative for utilizing this material can be developed. This study explores the characteristics of a naturally oxidized wet flue-gas desulfurization scrubber sludge and uses these characteristics to develop alternatives for recycling this material. In order for scrubber sludge to be used as a feed material for various markets, it was necessary to process it to meet the specifications of these markets. A physical separation process was therefore needed to separate the components of this sludge into useful products at a low cost. There are several physical separation techniques available to separate fine particulates. These techniques can be divided into four major groups: magnetic separation, electrostatic separation, physico-chemical separation, and density-based separation. The properties of this material indicated that two methods of separation were feasible: water-only cycloning (density-based separation), and froth flotation (physico-chemical separation). These processes could be used either separately, or in combination. The goal of this study was to reduce the limestone impurity in this scrubber sludge from 5.6% by weight to below 2.0% by weight. The resulting clean calcium

  16. Natural gas production and consumption 1979

    SciTech Connect

    Not Available

    1981-01-01

    Total marketed production of natural gas in the United States during 1979 was 20,471 billion cubic feet, an increase of approximately 497 billion cubic feet, or 2.5 percent over 1978. Texas and Louisiana, the two leading producing states, accounted for 70.5 percent of total 1979 marketed production. In 1979, deliveries of natural gas to residential, commercial, industrial, electric utilities, and other consumers totaled 18,141 billion cubic feet. Total consumption, which includes lease, plant, and pipeline fuel in addition to deliveries to consumers, was 20,241 billion cubic feet in 1979 compared to 19,627 billion cubic feet in 1978, an increase of 3.1 percent. Movements of natural gas into and out of each state are presented. Louisiana accounted for the largest quantity of net deliveries, 5,107 billion cubic feet, followed by Texas and Oklahoma with net deliveries of 2,772 billion cubic feet and 914 billion cubic feet, respectively. Imports of natural gas by pipeline from Canada and as liquefied natural gas (LNG) from Algeria totaled 1,253 billion cubic feet in 1979. Total imports increased 288 billion cubic feet, or 29.8 percent, from 1978 levels. Exports of LNG to Japan and pipeline shipments to Canada and Mexico increased 6.0 percent from 52.5 billion cubic feet in 1978 to 55.7 billion cubic feet in 1979. LNG shipments to Japan accounted for 92.1 percent of total exports in 1979.

  17. 21 CFR 173.350 - Combustion product gas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Combustion product gas. 173.350 Section 173.350... Combustion product gas. The food additive combustion product gas may be safely used in the processing and... manufactured by the controlled combustion in air of butane, propane, or natural gas. The combustion...

  18. Land application uses for dry flue gas desulfurization by-products. Executive summary

    SciTech Connect

    Dick, W.; Bigham, J.; Forster, R.; Hitzhusen, F.; Lal, R.; Stehouwer, R.; Traina, S.; Wolfe, W.; Haefner, R.; Rowe, G.

    1999-01-31

    Flue gas desulfurization (FGD) scrubbing technologies create several types of by-products. This project focused primarily on by-product materials obtained from what are commonly called ''dry scrubbers'' which produce a dry, solid material consisting of excess sorbent, reaction product that contains sulfate and sulfite, and coal fly ash. Prior to this project, dry FGD by-products were generally treated as solid wastes and disposed in landfills. However, landfill sites are becoming scarce and tipping fees are constantly increasing; The major objective of this project was to develop beneficial uses, via recycling, capable of providing economic benefits to both the producer and the end user of the FGD by-product. It is equally important, however, that the environmental impacts be carefully assessed so that the new uses developed are not only technically feasible but socially acceptable. Specific objectives developed for this project were derived over an 18-month period during extensive discussions with personnel from industry, regulatory agencies and research institutions. These were stated as follows: Objective 1: To characterize the material generated by dry FGD processes. Objective 2: To demonstrate the utilization of dry FGD by-product as a soil amendment on agricultural lands and on abandoned and active surface coal mines in Ohio. Objective 3: To demonstrate the use of dry FGD by-product as an engineering material for soil stabilization. Objective 4: To determine the quantities of dry FGD by-product that can be utilized in each of these applications. Objective 5. To determine the environmental and economic impacts of utilizing the material. Objective 6. To calibrate environmental, engineering, and economic models that can be used to determine the applicability and costs of utilizing these processes at other sites.

  19. A new economic instrument for financing accelerated landfill aftercare.

    PubMed

    Beaven, R P; Knox, K; Gronow, J R; Hjelmar, O; Greedy, D; Scharff, H

    2014-07-01

    The key aspects of landfill operation that remain unresolved are the extended timescale and uncertain funding of the post-closure period. This paper reviews the topic and proposes an economic instrument to resolve the unsustainable nature of the current situation. Unsustainability arises from the sluggish degradation of organic material and also the slow flushing of potential pollutants that is exacerbated by low-permeability capping. A landfill tax or aftercare provision rebate is proposed as an economic instrument to encourage operators to actively advance the stabilization of landfilled waste. The rebate could be accommodated within existing regulatory and tax regimes and would be paid for: (i) every tonne of nitrogen (or other agreed leachate marker) whose removal is advanced via the accelerated production and extraction of leachate; (ii) every tonne of non-commercially viable carbon removed via landfill gas collection and treatment. The rebates would be set at a level that would make it financially attractive to operators and would encourage measures such as leachate recirculation, in situ aeration, and enhanced flushing. Illustrative calculations suggest that a maximum rebate of up to ∼€50/tonne MSW would provide an adequate incentive.

  20. A new economic instrument for financing accelerated landfill aftercare.

    PubMed

    Beaven, R P; Knox, K; Gronow, J R; Hjelmar, O; Greedy, D; Scharff, H

    2014-07-01

    The key aspects of landfill operation that remain unresolved are the extended timescale and uncertain funding of the post-closure period. This paper reviews the topic and proposes an economic instrument to resolve the unsustainable nature of the current situation. Unsustainability arises from the sluggish degradation of organic material and also the slow flushing of potential pollutants that is exacerbated by low-permeability capping. A landfill tax or aftercare provision rebate is proposed as an economic instrument to encourage operators to actively advance the stabilization of landfilled waste. The rebate could be accommodated within existing regulatory and tax regimes and would be paid for: (i) every tonne of nitrogen (or other agreed leachate marker) whose removal is advanced via the accelerated production and extraction of leachate; (ii) every tonne of non-commercially viable carbon removed via landfill gas collection and treatment. The rebates would be set at a level that would make it financially attractive to operators and would encourage measures such as leachate recirculation, in situ aeration, and enhanced flushing. Illustrative calculations suggest that a maximum rebate of up to ∼€50/tonne MSW would provide an adequate incentive. PMID:24768257

  1. Methane oxidation in Swedish landfills quantified with the stable carbon isotope technique in combination with an optical method for emitted methane.

    PubMed

    Börjesson, Gunnar; Samuelsson, Jerker; Chanton, Jeffrey

    2007-10-01

    Methane budgets (production = emissions + oxidation + recovery) were estimated for six landfill sites in Sweden. Methane oxidation was measured in downwind plumes with a stable isotope technique (Chanton, J. P., et al., Environ. Sci Technol. 1999, 33, 3755-3760.) Positions in plumes for isotope sampling as well as methane emissions were determined with an optical instrument (Fourier Transform InfraRed) in combination with N20 as tracer gas (Galle, B., et al., Environ. Sci Technol. 2001, 35, 21-25.) Two landfills had been closed for years prior to the measurements, while four were active. Measurements at comparable soil temperatures showed that the two closed landfills had a significantly higher fraction of oxidized methane (38-42% of emission) relative to the four active landfills (4.6-15% of emission). These results highlight the importance of installing and maintaining effective landfill covers and also indicate that substantial amounts of methane escape from active landfills. Based on these results we recommend that the IPCC default values for methane oxidation in managed landfills could be set to 10% for active sites and 20% for closed sites. Gas recovery was found to be highly variable at the different sites, with values from 14% up to 65% of total methane production. The variance can be attributed to different waste management practices. PMID:17969681

  2. Stable isotope signatures for characterising the biological stability of landfilled municipal solid waste.

    PubMed

    Wimmer, Bernhard; Hrad, Marlies; Huber-Humer, Marion; Watzinger, Andrea; Wyhlidal, Stefan; Reichenauer, Thomas G

    2013-10-01

    Stable isotopic signatures of landfill leachates are influenced by processes within municipal solid waste (MSW) landfills mainly depending on the aerobic/anaerobic phase of the landfill. We investigated the isotopic signatures of δ(13)C, δ(2)H and δ(18)O of different leachates from lab-scale experiments, lysimeter experiments and a landfill under in situ aeration. In the laboratory, columns filled with MSW of different age and reactivity were percolated under aerobic and anaerobic conditions. In landfill simulation reactors, waste of a 25year old landfill was kept under aerobic and anaerobic conditions. The lysimeter facility was filled with mechanically shredded fresh waste. After starting of the methane production the waste in the lysimeter containments was aerated in situ. Leachate and gas composition were monitored continuously. In addition the seepage water of an old landfill was collected and analysed periodically before and during an in situ aeration. We found significant differences in the δ(13)C-value of the dissolved inorganic carbon (δ(13)C-DIC) of the leachate between aerobic and anaerobic waste material. During aerobic degradation, the signature of δ(13)C-DIC was mainly dependent on the isotopic composition of the organic matter in the waste, resulting in a δ(13)C-DIC of -20‰ to -25‰. The production of methane under anaerobic conditions caused an increase in δ(13)C-DIC up to values of +10‰ and higher depending on the actual reactivity of the MSW. During aeration of a landfill the aerobic degradation of the remaining organic matter caused a decrease to a δ(13)C-DIC of about -20‰. Therefore carbon isotope analysis in leachates and groundwater can be used for tracing the oxidation-reduction status of MSW landfills. Our results indicate that monitoring of stable isotopic signatures of landfill leachates over a longer time period (e.g. during in situ aeration) is a powerful and cost-effective tool for characterising the biodegradability and

  3. Landfill mining for resource recovery

    SciTech Connect

    Reith, C.C.

    1997-12-31

    Landfills are repositories of subeconomic resources. Landfill mining is an important enterprise that will someday return these resources to productive use, closing the loop on finite resources and stimulating economic development in communities near landfills. Secondary development of interred resources (landfill waste) will become economically viable as the environmental externalities of primary resource development -- e.g., the destruction of pristine habitat -- are more fully accounted for in programs of ecological design and design for environment. It is important to take an integrated and holistic approach to this new endeavor, which will be a complex assemblage of disciplines. Component disciplines include: resource economics, characterization, and excavation; contaminant control, and protection of environmental safety and health; material sorting, blending, and pretreatment; resource conversion, recovery, storage, and distribution; and reclamation for long-term land use. These technical elements must be addressed in close combination with compelling social issues such as environmental justice that may be especially critical in economically depressed communities surrounding today`s landfills.

  4. Learning from Landfills.

    ERIC Educational Resources Information Center

    Galus, Pamela

    2000-01-01

    Describes a project in which students developed an all-class laboratory activity called "The Decomposition of Organic and Inorganic Substances in a Landfill". Explores what conditions are necessary to facilitate decomposition in a landfill. (SAH)

  5. Sustainable treatment of landfill leachate

    NASA Astrophysics Data System (ADS)

    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.

  6. Waste degradation and gas production with enzymatic enhancement in anaerobic and aerobic landfill bioreactors.

    PubMed

    Hettiaratchi, J P A; Jayasinghe, P A; Bartholameuz, E M; Kumar, S

    2014-05-01

    The presence of lignin is the limiting factor at later stages of biodegradation of municipal solid waste under aerobic or anaerobic conditions. Supplying enzymes into the system could facilitate lignin degradation, thereby aiding anaerobic and aerobic waste degradation processes. A comprehensive set of laboratory experiments were conducted under both anaerobic and aerobic conditions to evaluate the feasibility of using enzymes in accelerating lignin-rich waste degradation. After 30 days of anaerobic operation, MnP and LiP enzyme treated reactors produced 36 and 23 times higher cumulative methane (CH4), respectively, compared to that of the control reactor devoid of enzyme treatments. The carbon dioxide (CO2) yield of MnP enhanced aerobic reactor showed more than two-fold increase.

  7. Waste degradation and gas production with enzymatic enhancement in anaerobic and aerobic landfill bioreactors.

    PubMed

    Hettiaratchi, J P A; Jayasinghe, P A; Bartholameuz, E M; Kumar, S

    2014-05-01

    The presence of lignin is the limiting factor at later stages of biodegradation of municipal solid waste under aerobic or anaerobic conditions. Supplying enzymes into the system could facilitate lignin degradation, thereby aiding anaerobic and aerobic waste degradation processes. A comprehensive set of laboratory experiments were conducted under both anaerobic and aerobic conditions to evaluate the feasibility of using enzymes in accelerating lignin-rich waste degradation. After 30 days of anaerobic operation, MnP and LiP enzyme treated reactors produced 36 and 23 times higher cumulative methane (CH4), respectively, compared to that of the control reactor devoid of enzyme treatments. The carbon dioxide (CO2) yield of MnP enhanced aerobic reactor showed more than two-fold increase. PMID:24684817

  8. Effect of moisture control and air venting on H2S production and leachate quality in mature C&D debris landfills.

    PubMed

    Zhang, Jianye; Dubey, Brajesh; Townsend, Timothy

    2014-10-21

    The effect of air venting and moisture variation on H2S production and the leaching of metals/metalloids (arsenic, copper, chromium, and boron) from treated wood in aged mature construction and demolition (C&D) debris landfills were examined. Three simulated C&D debris landfill lysimeters were constructed and monitored, each containing as a major debris component either wooden pallets, chromated copper arsenate (CCA) treated wood, or alkaline copper quaternary (ACQ) treated wood. The lysimeters were operated with alternating periods of water addition (a total of 160 L in four equal amounts) and air venting (68.4 m(3)per day for 121 days in two phases). Moisture addition did not increase H2S levels in the long term, and a significant drop in H2S concentration was observed (up to 99%) when aerobic conditions were promoted through air venting. H2S concentrations increased after venting stopped up to values approximately two orders of magnitude lower than observed prior to venting. Venting had the immediate consequence of suppressing biological H2S production, and the longer-term effect of decreasing organic matter that could otherwise be utilized in this process. Under aerobic conditions, the levels of arsenic, chromium, and boron in leachate decreased up to 96%, 49%, and 68%, respectively, while copper was found to increase up to 200% in CCA and 445% in ACQ column leachates.

  9. Effect of moisture control and air venting on H2S production and leachate quality in mature C&D debris landfills.

    PubMed

    Zhang, Jianye; Dubey, Brajesh; Townsend, Timothy

    2014-10-21

    The effect of air venting and moisture variation on H2S production and the leaching of metals/metalloids (arsenic, copper, chromium, and boron) from treated wood in aged mature construction and demolition (C&D) debris landfills were examined. Three simulated C&D debris landfill lysimeters were constructed and monitored, each containing as a major debris component either wooden pallets, chromated copper arsenate (CCA) treated wood, or alkaline copper quaternary (ACQ) treated wood. The lysimeters were operated with alternating periods of water addition (a total of 160 L in four equal amounts) and air venting (68.4 m(3)per day for 121 days in two phases). Moisture addition did not increase H2S levels in the long term, and a significant drop in H2S concentration was observed (up to 99%) when aerobic conditions were promoted through air venting. H2S concentrations increased after venting stopped up to values approximately two orders of magnitude lower than observed prior to venting. Venting had the immediate consequence of suppressing biological H2S production, and the longer-term effect of decreasing organic matter that could otherwise be utilized in this process. Under aerobic conditions, the levels of arsenic, chromium, and boron in leachate decreased up to 96%, 49%, and 68%, respectively, while copper was found to increase up to 200% in CCA and 445% in ACQ column leachates. PMID:25244062

  10. T2LBM Version 1.0: Landfill bioreactor model for TOUGH2

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2002-12-01

    elimination of methane production and acceleration of waste decomposition. In the first phase of this project a 12-acre module that contains a 9.5-acre anaerobic cell and a 2.5-acre aerobic cell has been constructed and filled with over 220,000 tons of municipal solid waste. Water and leachate addition began in April 2002 and to date less than 200,000 gallons of liquid has been added to the 3.5-acre anaerobic cell. The waste filling phase of the aerobic cell was completed in June of 2002 and a 12-inches soil cover and 12-inches of greenwaste compost cover was placed on top of the cell. A vacuum will be applied to the piping within the waste to draw air through the landfill. Instrumentations have been installed to monitor the following parameters: waste temperature, moisture, leachate volumes, leachate hydraulic head over the primary liner, leachate composition, gas volumes and composition. A supervisory Control and Data Acquisition (SCADA) system has been installed to monitor and control the operation of the bioreactor cells. Waste samples were taken from each cell for laboratory testing in early June 2002.

  12. Modelling of environmental impacts of solid waste landfilling within the life-cycle analysis program EASEWASTE

    SciTech Connect

    Kirkeby, Janus T.; Birgisdottir, Harpa; Bhander, Gurbakash Singh; Hauschild, Michael; Christensen, Thomas H.

    2007-07-01

    A new computer-based life-cycle assessment model (EASEWASTE) has been developed to evaluate resource and environmental consequences of solid waste management systems. This paper describes the landfilling sub-model used in the life-cycle assessment program EASEWASTE, and examines some of the implications of this sub-model. All quantities and concentrations of leachate and landfill gas can be modified by the user in order to bring them in agreement with the actual landfill that is assessed by the model. All emissions, except the generation of landfill gas, are process specific. The landfill gas generation is calculated on the basis of organic matter in the landfilled waste. A landfill assessment example is provided. For this example, the normalised environmental effects of landfill gas on global warming and photochemical smog are much greater than the environmental effects for landfill leachate or for landfill construction. A sensitivity analysis for this example indicates that the overall environmental impact is sensitive to the gas collection efficiency and the use of the gas, but not to the amount of leachate generated, or the amount of soil or liner material used in construction. The landfill model can be used for evaluating different technologies with different liners, gas and leachate collection efficiencies, and to compare the environmental consequences of landfilling with alternative waste treatment options such as incineration or anaerobic digestion.

  13. Generating CO(2)-credits through landfill in situ aeration.

    PubMed

    Ritzkowski, M; Stegmann, R

    2010-04-01

    Landfills are some of the major anthropogenic sources of methane emissions worldwide. The installation and operation of gas extraction systems for many landfills in Europe and the US, often including technical installations for energy recovery, significantly reduced these emissions during the last decades. Residual landfill gas, however, is still continuously produced after the energy recovery became economically unattractive, thus resulting in ongoing methane emissions for many years. By landfill in situ aeration these methane emissions can be widely avoided both, during the aeration process as well as in the subsequent aftercare period. Based on model calculations and online monitoring data the amount of avoided CO(2-eq). can be determined. For an in situ aerated landfill in northern Germany, acting as a case study, 83-95% (depending on the kind and quality of top cover) of the greenhouse gas emission potential could be reduced under strictly controlled conditions. Recently the United Nations Framework Convention on Climate Change (UNFCCC) has approved a new methodology on the "Avoidance of landfill gas emissions by in situ aeration of landfills" (UNFCCC, 2009). Based on this methodology landfill aeration projects might be considered for generation of Certified Emission Reductions (CERs) in the course of CDM projects. This paper contributes towards an evaluation of the potential of landfill aeration for methane emissions reduction.

  14. Quantification of methane emissions from 15 Danish landfills using the mobile tracer dispersion method

    SciTech Connect

    Mønster, Jacob; Samuelsson, Jerker; Scheutz, Charlotte

    2015-01-15

    Highlights: • Quantification of whole landfill site methane emission at 15 landfills. • Multiple on-site source identification and quantification. • Quantified methane emission from shredder waste and composting. • Large difference between measured and reported methane emissions. - Abstract: Whole-site methane emissions from 15 Danish landfills were assessed using a mobile tracer dispersion method with either Fourier transform infrared spectroscopy (FTIR), using nitrous oxide as a tracer gas, or cavity ring-down spectrometry (CRDS), using acetylene as a tracer gas. The landfills were chosen to represent the different stages of the lifetime of a landfill, including open, active, and closed covered landfills, as well as those with and without gas extraction for utilisation or flaring. Measurements also included landfills with biocover for oxidizing any fugitive methane. Methane emission rates ranged from 2.6 to 60.8 kg h{sup −1}, corresponding to 0.7–13.2 g m{sup −2} d{sup −1}, with the largest emission rates per area coming from landfills with malfunctioning gas extraction systems installed, and the smallest emission rates from landfills closed decades ago and landfills with an engineered biocover installed. Landfills with gas collection and recovery systems had a recovery efficiency of 41–81%. Landfills where shredder waste was deposited showed significant methane emissions, with the largest emission from newly deposited shredder waste. The average methane emission from the landfills was 154 tons y{sup −1}. This average was obtained from a few measurement campaigns conducted at each of the 15 landfills and extrapolating to annual emissions requires more measurements. Assuming that these landfills are representative of the average Danish landfill, the total emission from Danish landfills were calculated at 20,600 tons y{sup −1}, which is significantly lower than the 33,300 tons y{sup −1} estimated for the national greenhouse gas inventory for

  15. 21 CFR 173.350 - Combustion product gas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Combustion product gas. 173.350 Section 173.350... CONSUMPTION Specific Usage Additives § 173.350 Combustion product gas. The food additive combustion product gas may be safely used in the processing and packaging of the foods designated in paragraph (c)...

  16. 21 CFR 173.350 - Combustion product gas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Combustion product gas. 173.350 Section 173.350... CONSUMPTION Specific Usage Additives § 173.350 Combustion product gas. The food additive combustion product gas may be safely used in the processing and packaging of the foods designated in paragraph (c)...

  17. 21 CFR 173.350 - Combustion product gas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Combustion product gas. 173.350 Section 173.350... CONSUMPTION Specific Usage Additives § 173.350 Combustion product gas. The food additive combustion product gas may be safely used in the processing and packaging of the foods designated in paragraph (c)...

  18. 21 CFR 173.350 - Combustion product gas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Combustion product gas. 173.350 Section 173.350... CONSUMPTION Specific Usage Additives § 173.350 Combustion product gas. The food additive combustion product gas may be safely used in the processing and packaging of the foods designated in paragraph (c)...

  19. CO Methanation for Synthetic Natural Gas Production.

    PubMed

    Kambolis, Anastasios; Schildhauer, Tilman J; Kröcher, Oliver

    2015-01-01

    Energy from woody biomass could supplement renewable energy production towards the replacement of fossil fuels. A multi-stage process involving gasification of wood and then catalytic transformation of the producer gas to synthetic natural gas (SNG) represents progress in this direction. SNG can be transported and distributed through the existing pipeline grid, which is advantageous from an economical point of view. Therefore, CO methanation is attracting a great deal of attention and much research effort is focusing on the understanding of the process steps and its further development. This short review summarizes recent efforts at Paul Scherrer Institute on the understanding of the reaction mechanism, the catalyst deactivation, and the development of catalytic materials with benign properties for CO methanation. PMID:26598405

  20. Bio gas oil production from waste lard.

    PubMed

    Hancsók, Jeno; Baladincz, Péter; Kasza, Tamás; Kovács, Sándor; Tóth, Csaba; Varga, Zoltán

    2011-01-01

    Besides the second generations bio fuels, one of the most promising products is the bio gas oil, which is a high iso-paraffin containing fuel, which could be produced by the catalytic hydrogenation of different triglycerides. To broaden the feedstock of the bio gas oil the catalytic hydrogenation of waste lard over sulphided NiMo/Al(2)O(3) catalyst, and as the second step, the isomerization of the produced normal paraffin rich mixture (intermediate product) over Pt/SAPO-11 catalyst was investigated. It was found that both the hydrogenation and the decarboxylation/decarbonylation oxygen removing reactions took place but their ratio depended on the process parameters (T = 280-380°C, P = 20-80 bar, LHSV = 0.75-3.0  h(-1) and H(2)/lard ratio: 600  Nm(3)/m(3)). In case of the isomerization at the favourable process parameters (T = 360-370°C, P = 40-50 bar, LHSV = 1.0  h(-1) and H(2)/hydrocarbon ratio: 400  Nm(3)/m(3)) mainly mono-branching isoparaffins were obtained. The obtained products are excellent Diesel fuel blending components, which are practically free of heteroatoms. PMID:21403875

  1. Landfill capping: The Croton Point Landfill experience

    SciTech Connect

    Srinivasaraghaven, R.; Gavin, J.M.; Landi, A.M.; Ritchie, M.D.

    1996-12-31

    The Croton Point Landfill Capping involved the installation of an impermeable, geosynthetic cap and the attendant geotechnical cover soils over a 113 acre hazardous waste landfill in Croton-On-Hudson, New York. The remediation process - Remedial Investigation, Feasibility Study (RI/FS) Remedial Design and Remedial Construction lasted six years. This paper sets forth some of the insights and experiences gained during that process and provides some practical recommendations. In particular, the paper evaluates the Croton Landfill experience in regard to Health and Safety; Stormwater Control; erosion and sediment control; QA/QC; leachate treatment and disposal; and wildlife control.

  2. Expanding Canadian natural gas production will strengthen growth of LP-gas industry

    SciTech Connect

    Hawkins, D.J. )

    1994-01-01

    In 1992, over 86% of Canadian propane and 70% of Canadian butane production originated in gas plants. Propane and butane production not recovered at gas plants is recovered in other processing facilities, primarily refineries and heavy oil upgraders. As a result, supplies of both products are largely tied to natural gas production, and the outlook for natural gas therefore provides the basis for any discussion on the outlook for gas processing and NGL industry infrastructure. The paper discusses gas processing, economies of scale, NGL supply, expected declines, industry structure and infrastructure, the two major centers of the Canadian NGL industry, new shippers, and required pipeline expansion.

  3. ETV/ESTCP Demonstration Plan - Demonstration and Verification of a Turbine Power Generation System Utilizing Renewable Fuel: Landfill Gas

    EPA Science Inventory

    This Test and Quality Assurance Plan (TQAP) provides data quality objections for the success factors that were validated during this demonstration include energy production, emissions and emission reductions compared to alternative systems, economics, and operability, including r...

  4. High rate of methane leakage from natural gas production

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-10-01

    Natural gas production is growing as the United States seeks domestic sources of relatively clean energy. Natural gas combustion produces less carbon dioxide emissions than coal or oil for the amount of energy produced. However, one source of concern is that some natural gas leaks to the atmosphere from the extraction point, releasing methane, a potent greenhouse gas.

  5. Comparison of Landfill Methane Oxidation Measured Using Stable Isotope Analysis and CO2/CH4 Fluxes Measured by the Eddy Covariance Method

    NASA Astrophysics Data System (ADS)

    Xu, L.; Chanton, J.; McDermitt, D. K.; Li, J.; Green, R. B.

    2015-12-01

    Methane plays a critical role in the radiation balance and chemistry of the atmosphere. Globally, landfill methane emission contributes about 10-19% of the anthropogenic methane burden into the atmosphere. In the United States, 18% of annual anthropogenic methane emissions come from landfills, which represent the third largest source of anthropogenic methane emissions, behind enteric fermentation and natural gas and oil production. One uncertainty in estimating landfill methane emissions is the fraction of methane oxidized when methane produced under anaerobic conditions passes through the cover soil. We developed a simple stoichiometric model to estimate methane oxidation fraction when the anaerobic CO2 / CH4 production ratio is known, or can be estimated. The model predicts a linear relationship between CO2 emission rates and CH4 emission rates, where the slope depends on anaerobic CO2 / CH4 production ratio and the fraction of methane oxidized, and the intercept depends on non-methane-dependent oxidation processes. The model was tested using carbon dioxide emission rates (fluxes) and methane emission rates (fluxes) measured using the eddy covariance method over a one year period at the Turkey Run landfill in Georgia, USA. The CO2 / CH4 production ratio was estimated by measuring CO2 and CH4 concentrations in air sampled under anaerobic conditions deep inside the landfill. We also used a mass balance approach to independently estimate fractional oxidation based on stable isotope measurements (δ13C of methane) of gas samples taken from deep inside the landfill and just above the landfill surface. Results from the two independent methods agree well. The model will be described and methane oxidation will be discussed in relation to wind direction, location at the landfill, and age of the deposited refuse.

  6. Remediation of an old landsfill site: soil analysis, leachate quality and gas production.

    PubMed

    Hogland, William

    2002-01-01

    The Baltic Sea Region has a large number of landfills that need remediation after care routines and control, in order to avoid future emissions to the environment and to fulfil the demands in the EU Waste Council Directive on the landfill of waste. Based on the Måsalycke test screening, an excavation of whole or of parts of the landfill can be seen as a potential measure for some of the old landfills. The material excavated in the test was screened into the fractions: < 18 mm, 18-50 mm and > 50 mm. The coarsest fraction (> 50 mm) contained 50% wood and paper. The medium-sized fraction (18-50 mm) contained stones and indefinable soil-like material, while the fine fraction contained peat-like material with some other small waste components. The spectral analysis of heavy metals indicated only high concentrations of zinc and there was no significant difference between the fine and the medium-sized fractions. The medium sized and the unsorted fraction was moisturized and refilled into the pit. The methane content in the landfill gas from the pit was 50-57% in the sorted material with a flow of 8-17 l/min and 38-57% in the unsorted fraction with a flow of 2-13 l/min during the first 1.5 year. The Måsalycke landfill is in the methanogenic phase and leachate concentrations are normal. Landfill mining can be used to prolong the landfill lifetime and/or used as a tool for remedial actions in contaminated sites. PMID:12638749

  7. Gas-well production decline in multiwell reservoirs

    SciTech Connect

    Aminian, K.; Ameri, S. ); Stark, J.J. ); Yost, A.B. II )

    1990-12-01

    This paper introduces a pseudosteady-state constant-pressure solution for gas wells. The solution was used to develop a type-curve-based method to history match and predict multiwell gas reservoir production. Good agreements between the predicted and actual gas well production rates were obtained.

  8. EPA's Global Climate Change Program. Program plan for methane emissions from landfills and other waste disposal facilities

    SciTech Connect

    Thorneloe, S.A.

    1991-03-26

    The paper discusses a portion of EPA's global climate change program, a program plan for methane emissions from landfills and other waste disposal facilities. In response to concerns about global climate change, the U.S. EPA's Office of Research and Development (ORD) has initiated an emissions and mitigation program. ORD's Air and Energy Engineering Research Laboratory (AEERL) has begun research on greenhouse gas emission estimation, biomass and methane utilization, tropospheric ozone, and evaluation of potential mitigation opportunities for emissions contributing to global climate change. The emissions program has begun to identify and quantify emission sources of greenhouse gases for anthropogenic sources including landfills, coal mines, natural gas production/distribution, cook stoves, and biomass burning. Development of enhanced emission estimates will improve the understanding of atmospheric chemistry and feedback effects, target mitigation opportunities, and ensure cost-effective mitigation strategies. The focus of the paper is on AEERL's research efforts on global landfill methane.

  9. Land application uses for dry flue gas desulfurization by-products: Phase 2. Final report

    SciTech Connect

    Stehouwer, R.; Dick, W.; Bigham, J.

    1998-03-01

    The Clean Air Act, as amended in 1990, spurred the development of flue gas desulfurization (FGD) technologies, several of which produce a dry, solid by-product material consisting of excess sorbent, reaction products containing sulfates and sulfites, and coal fly ash. A three-phase study was initiated in December 1990 to demonstrate high-volume beneficial uses of FGD by-products as alternates to landfilling. Phase 1 characterized the chemical, physical, mineralogical, and engineering properties of FGD by-products from 13 coal-fired boilers, and provided a preliminary evaluation of the economic feasibility of various FGD by-product applications. This report covers Phase 2 of the study, which included (1) laboratory and greenhouse studies to evaluate the use of dry FGD by-products as a soil conditioning amendment for acidic minespoils and agricultural soils, (2) field studies to test several high-volume agronomic and engineering uses, and (3) development and preliminary application of a basic methodological framework for estimation of the economic costs and benefits to society of various beneficial reuse options.

  10. ESTIMATE OF GLOBAL METHANE EMISSIONS FROM LANDFILLS AND OPEN DUMPS

    EPA Science Inventory

    The report presents an empirical model to estimate global methane (CH4) emissions from landfills and open dumps based on EPA data from landfill gas (LFG) recovery projects. The EPA CH4 estimates for 1990 range between 19 and 40 teragrams (10 to the 12th power) per year (Tg/yr), w...

  11. Geohydrology and ground-water geochemistry at a sub-arctic landfill, Fairbanks, Alaska

    USGS Publications Warehouse

    Downey, J.S.

    1990-01-01

    The Fairbanks-North Star Borough, Alaska, landfill is located on silt, sand, and gravel deposits of the Tanana River flood plain, about 3 miles south of the city of Fairbanks water supply wells. The landfill has been in operation for about 25 years in this sub-arctic region of discontinuous permafrost. The cold climate limits biological activity within the landfill with corresponding low gas and leachate production. Chloride concentrations, specific conductance, water temperature, and earth conductivity measurements indicate a small plume of leachate flowing to the northwest from the landfill. The leachate remains near the water table as it flows northwestward toward a drainage ditch. Results of computer modeling of this local hydrologic system indicate that some of the leachate may be discharging to the ditch. Chemical data show that higher-than-background concentrations of several ions are present in the plume. However, the concentrations appear to be reduced to background levels within a short distance along the path of groundwater flow from the landfill, and thus the leachate is not expected to affect the water supply wells. (USGS)

  12. Ground movements associated with gas hydrate production

    SciTech Connect

    Siriwardane, H.J.

    1992-10-01

    The mechanics of ground movements during hydrate production can be more closely simulated by considering similarities with ground movements associated with subsidence in permafrost regions than with gob compaction in a longwall mine. The purpose of this research work is to investigate the potential strata movements associated with hydrate production by considering similarities with ground movements in permafrost regions. The work primarily involves numerical modeling of subsidence caused by hydrate dissociation. The investigation is based on the theories of continuum mechanics , thermomechanical behavior of frozen geo-materials, and principles of rock mechanics and geomechanics. It is expected that some phases of the investigation will involve the use of finite element method, which is a powerful computer-based method which has been widely used in many areas of science and engineering. Parametric studies will be performed to predict expected strata movements and surface subsidence for different reservoir conditions and properties of geological materials. The results from this investigation will be useful in predicting the magnitude of the subsidence problem associated with gas hydrate production. The analogy of subsidence in permafrost regions may provide lower bounds for subsidence expected in hydrate reservoirs. Furthermore, it is anticipated that the results will provide insight into planning of hydrate recovery operations.

  13. Landfill disposal systems

    PubMed Central

    Slimak, Karen M.

    1978-01-01

    The current status of landfill disposal of hazardous wastes in the United States is indicated by presenting descriptions of six operating landfills. These landfills illustrate the variety of techniques that exist in landfill disposal of hazardous wastes. Although some landfills more effectively isolate hazardous waste than others, all landfills must deal with the following problems. Leachate from hazardous waste landfills is generally highly polluted. Most landfills attempt to contain leachate at the site and prevent its discharge to surface or groundwaters. To retain leachate within a disposal area, subsurface barriers of materials such as concrete, asphalt, butyl rubber, vinyl, and clay are used. It is difficult to assure that these materials can seal a landfill indefinitely. When a subsurface barrier fails, the leachate enters the groundwater in a concentrated, narrow band which may bypass monitoring wells. Once a subsurface barrier has failed, repairs are time-consuming and costly, since the waste above the repair site may have to be removed. The central problem in landfill disposal is leachate control. Recent emphasis has been on developing subsurface barriers to contain the wastes and any leachate. Future emphasis should also be on techniques for removing water from hazardous wastes before they are placed in landfills, and on methods for preventing contact of the wastes with water during and after disposal operations. When leachate is eliminated, the problems of monitoring, and subsurface barrier failure and repair can be addressed, and a waste can be effectively isolated. A surface seal landfill design is recommended for maintaining the dry state of solid hazardous wastes and for controlling leachate. Any impervious liner is utilized over the top of the landfill to prevent surface water from seeping into the waste. The surface barrier is also the site where monitoring and maintenance activities are focused. Barrier failure can be detected by visual

  14. Aerobic landfill bioreactor

    DOEpatents

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

    2002-01-01

    The present invention includes a system 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.

  15. Aerobic landfill bioreactor

    DOEpatents

    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.

  16. Aerobic landfill bioreactor

    SciTech Connect

    Hudgins, M.P.; Bessette, B.J.; March, J.; McComb, S.T.

    2000-02-15

    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 F and 140 F in steady state.

  17. Gas Production Strategy of Underground Coal Gasification Based on Multiple Gas Sources

    PubMed Central

    Tianhong, Duan; Zuotang, Wang; Limin, Zhou; Dongdong, Li

    2014-01-01

    To lower stability requirement of gas production in UCG (underground coal gasification), create better space and opportunities of development for UCG, an emerging sunrise industry, in its initial stage, and reduce the emission of blast furnace gas, converter gas, and coke oven gas, this paper, for the first time, puts forward a new mode of utilization of multiple gas sources mainly including ground gasifier gas, UCG gas, blast furnace gas, converter gas, and coke oven gas and the new mode was demonstrated by field tests. According to the field tests, the existing power generation technology can fully adapt to situation of high hydrogen, low calorific value, and gas output fluctuation in the gas production in UCG in multiple-gas-sources power generation; there are large fluctuations and air can serve as a gasifying agent; the gas production of UCG in the mode of both power and methanol based on multiple gas sources has a strict requirement for stability. It was demonstrated by the field tests that the fluctuations in gas production in UCG can be well monitored through a quality control chart method. PMID:25114953

  18. Greenhouse gas and carbon profile of the u.s. Forest products industry value chain.

    PubMed

    Heath, Linda S; Maltby, Van; Miner, Reid; Skog, Kenneth E; Smith, James E; Unwin, Jay; Upton, Brad

    2010-05-15

    A greenhouse gas and carbon accounting profile was developed for the U.S. forest products industry value chain for 1990 and 2004-2005 by examining net atmospheric fluxes of CO(2) and other greenhouse gases (GHGs) using a variety of methods and data sources. Major GHG emission sources include direct and indirect (from purchased electricity generation) emissions from manufacturing and methane emissions from landfilled products. Forest carbon stocks in forests supplying wood to the industry were found to be stable or increasing. Increases in the annual amounts of carbon removed from the atmosphere and stored in forest products offset about half of the total value chain emissions. Overall net transfers to the atmosphere totaled 91.8 and 103.5 TgCO(2)-eq. in 1990 and 2005, respectively, although the difference between these net transfers may not be statistically significant. Net transfers were higher in 2005 primarily because additions to carbon stored in forest products were less in 2005. Over this same period, energy-related manufacturing emissions decreased by almost 9% even though forest products output increased by approximately 15%. Several types of avoided emissions were considered separately and were collectively found to be notable relative to net emissions.

  19. Greenhouse Gas and Carbon Profile of the U.S. Forest Products Industry Value Chain

    PubMed Central

    2010-01-01

    A greenhouse gas and carbon accounting profile was developed for the U.S. forest products industry value chain for 1990 and 2004−2005 by examining net atmospheric fluxes of CO2 and other greenhouse gases (GHGs) using a variety of methods and data sources. Major GHG emission sources include direct and indirect (from purchased electricity generation) emissions from manufacturing and methane emissions from landfilled products. Forest carbon stocks in forests supplying wood to the industry were found to be stable or increasing. Increases in the annual amounts of carbon removed from the atmosphere and stored in forest products offset about half of the total value chain emissions. Overall net transfers to the atmosphere totaled 91.8 and 103.5 TgCO2-eq. in 1990 and 2005, respectively, although the difference between these net transfers may not be statistically significant. Net transfers were higher in 2005 primarily because additions to carbon stored in forest products were less in 2005. Over this same period, energy-related manufacturing emissions decreased by almost 9% even though forest products output increased by approximately 15%. Several types of avoided emissions were considered separately and were collectively found to be notable relative to net emissions. PMID:20355695

  20. Initial results of detected methane emissions from landfills in the Los Angeles Basin during the COMEX campaign by the Methane Airborne MAPper (MAMAP) instrument and a greenhouse gas in-situ analyser

    NASA Astrophysics Data System (ADS)

    Krautwurst, Sven; Gerilowski, Konstantin; Kolyer, Richard; Jonsson, Haflidi; Krings, Thomas; Horstjann, Markus; Leifer, Ira; Vigil, Sam; Buchwitz, Michael; Schüttemeyer, Dirk; Fladeland, Matthew M.; Burrows, John P.; Bovensmann, Heinrich

    2015-04-01

    Methane (CH4) is the second most important anthropogenic greenhouse gas beside carbon dioxide (CO2). Significant contributors to the global methane budget are fugitive emissions from landfills. Due to the growing world population, it is expected that the amount of waste and, therefore, waste disposal sites will increase in number and size in parts of the world, often adjacent growing megacities. Besides bottom-up modelling, a variety of ground based methods (e.g., flux chambers, trace gases, radial plume mapping, etc.) have been used to estimate (top-down) these fugitive emissions. Because landfills usually are large, sometimes with significant topographic relief, vary temporally, and leak/emit heterogeneously across their surface area, assessing total emission strength by ground-based techniques is often difficult. In this work, we show how airborne based remote sensing measurements of the column-averaged dry air mole fraction of CH4 can be utilized to estimate fugitive emissions from landfills in an urban environment by a mass balance approach. Subsequently, these emission rates are compared to airborne in-situ horizontal cross section measurements of CH4 taken within the planetary boundary layer (PBL) upwind and downwind of the landfill at different altitudes immediately after the remote sensing measurements were finished. Additional necessary parameters (e.g., wind direction, wind speed, aerosols, dew point temperature, etc.) for the data inversion are provided by a standard instrumentation suite for atmospheric measurements aboard the aircraft, and nearby ground-based weather stations. These measurements were part of the CO2 and Methane EXperiment (COMEX), which was executed during the summer 2014 in California and was co-funded by the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA). The remote sensing measurements were taken by the Methane Airborne MAPper (MAMAP) developed and operated by the University of Bremen and

  1. The role of mechanical and biological treatment in reducing methane emissions from landfill disposal of municipal solid waste in the United Kingdom.

    PubMed

    Pan, Jilang; Voulvoulis, Nickolaos

    2007-02-01

    In Europe, the European Union Landfill Directive aims to reduce the negative environmental impacts of landfilling. This is mainly to be achieved by reducing the quantity of organic matter deposited, through measures such as the separate collection and recycling of the organic waste stream or pretreatment of residual wastes before landfilling. Other than incineration or other thermal processes, mechanical biological treatment is playing an increasingly important role. This study was conducted to seek the benefits of municipal solid waste (MSW) pretreatment, as well as the differences in methane production from the landfilling of untreated and mechanically/biologically treated (MBT) MSW using GasSim simulation. Results demonstrated that methane production rates vary significantly among waste fractions. Those that contribute most to methane generation (organic material and potentially reusable or recyclable material) could be targeted and treated before landfilling. The statistic relationship from the first phase of the study indicated that to match the increasingly stringent landfill waste organic content allowance, local councils should prioritize the reduction/sorting of certain targeted fractions, such as paper, card, green waste, and other putrescibles from MSW. Moreover, mechanical treatment alone produces organic-rich waste called mechanically sorted organic residues (MSORs), which can be viewed as an organic content concentration process. Mechanically and biologically pretreated waste, on the other hand, differs significantly from untreated MSW and MSORs. This work demonstrated that if efficient mechanical-biological treatment is used, considerable reductions in biological activity, landfill gas production, and energy content/total organic carbon could be achieved. Using GasSim, reductions in methane production of >74% have been simulated if a 90% organic content reduction can be achieved during biological treatment on MSORs. A 50-60% organic content reduction

  2. Measuring and managing reservoir greenhouse gas emissions

    EPA Science Inventory

    Methane (CH4) is the second most important anthropogenic greenhouse gas with a heat trapping capacity 34 times greater than that of carbon dioxide on a 100 year time scale. Known anthropogenic CH4 sources include livestock production, rice agriculture, landfills, and natural gas...

  3. Stable isotope signatures for characterising the biological stability of landfilled municipal solid waste

    SciTech Connect

    Wimmer, Bernhard; Hrad, Marlies; Huber-Humer, Marion; Watzinger, Andrea; Wyhlidal, Stefan; Reichenauer, Thomas G.

    2013-10-15

    Highlights: ► The isotopic signature of δ{sup 13}C-DIC of leachates is linked to the reactivity of MSW. ► Isotopic signatures of leachates depend on aerobic/anaerobic conditions in landfills. ► In situ aeration of landfills can be monitored by isotope analysis in leachate. ► The isotopic analysis of leachates can be used for assessing the stability of MSW. ► δ{sup 13}C-DIC of leachates helps to define the duration of landfill aftercare. - Abstract: Stable isotopic signatures of landfill leachates are influenced by processes within municipal solid waste (MSW) landfills mainly depending on the aerobic/anaerobic phase of the landfill. We investigated the isotopic signatures of δ{sup 13}C, δ{sup 2}H and δ{sup 18}O of different leachates from lab-scale experiments, lysimeter experiments and a landfill under in situ aeration. In the laboratory, columns filled with MSW of different age and reactivity were percolated under aerobic and anaerobic conditions. In landfill simulation reactors, waste of a 25 year old landfill was kept under aerobic and anaerobic conditions. The lysimeter facility was filled with mechanically shredded fresh waste. After starting of the methane production the waste in the lysimeter containments was aerated in situ. Leachate and gas composition were monitored continuously. In addition the seepage water of an old landfill was collected and analysed periodically before and during an in situ aeration. We found significant differences in the δ{sup 13}C-value of the dissolved inorganic carbon (δ{sup 13}C-DIC) of the leachate between aerobic and anaerobic waste material. During aerobic degradation, the signature of δ{sup 13}C-DIC was mainly dependent on the isotopic composition of the organic matter in the waste, resulting in a δ{sup 13}C-DIC of −20‰ to −25‰. The production of methane under anaerobic conditions caused an increase in δ{sup 13}C-DIC up to values of +10‰ and higher depending on the actual reactivity of the MSW

  4. Emissions of Nonmethane Organic Compounds at an Illinois (USA) Landfill: Preliminary Field Measurements

    SciTech Connect

    Bogner, J.; Spokas, K.; Niemann, M.; Niemann, L.; Baker, J.

    1997-08-01

    Current US regulatory models for estimating emissions of nonmethane organic compounds (NMOCs) from municipal solid waste (MSW) landfills require field validation to determine if the models are realistic. A project was initiated to begin to develop a field method for direct measurement of landfill NMOC emissions and, concurrently, develop improved sampling and analysis methods for individual NMOCs in landfill gas matrices. Two contrasting field sites at the Greene Valley Landfill, DuPage County, Illinois, USA, were established.

  5. Identification of Cellulose Breaking Bacteria in Landfill Samples for Organic Waste Management

    NASA Astrophysics Data System (ADS)

    Chan, P. M.; Leung, F. C.

    2015-12-01

    According to the Hong Kong Environmental Protection Department, the citizens of Hong Kong disposes 13,500 tonnes of waste to the landfill everyday. Out of the 13,500 tonnes, 3600 tonnes consist of organic waste. Furthermore, due to the limited supply of land for landfills in Hong Kong, it is estimated that landfills will be full by about 2020. Currently, organic wastes at landfills undergo anaerobic respiration, where methane gas, one of the most harmful green house gases, will be released. The management of such waste is a pressing issue, as possible solutions must be presented in this crucial period of time. The Independent Schools Foundation Academy introduced their very own method to manage the waste produced by the students. With an approximate of 1500 students on campus, the school produces 27 metric tonnes of food waste each academic year. The installation of the rocket food composter provides an alternate method of disposable of organic waste the school produces, for the aerobic environment allows for different by-products to be produced, namely compost that can be used for organic farming by the primary school students and subsequently carbon dioxide, a less harmful greenhouse gas. This research is an extension on the current work, as another natural factor is considered. It evaluates the microorganism community present in leachate samples collected from the North East New Territories Landfill, for the bacteria in the area exhibits special characteristics in the process of decomposition. Through the sequencing and analysis of the genome of the bacteria, the identification of the bacteria might lead to a break through on the current issue. Some bacteria demonstrate the ability to degrade lignin cellulose, or assist in the production of methane gas in aerobic respirations. These characteristics can hopefully be utilized in the future in waste managements across the globe.

  6. Polybrominated diphenyl ethers (PBDEs) in leachates from selected landfill sites in South Africa

    SciTech Connect

    Odusanya, David O.; Okonkwo, Jonathan O. Botha, Ben

    2009-01-15

    The last few decades have seen dramatic growth in the scale of production and the use of polybrominated diphenyl ethers (PBDEs) as flame retardants. Consequently, PBDEs such as BDE -28, -47, -66, -71, -75, -77, -85, -99, -100, -119, -138, -153, -154, and -183 have been detected in various environmental matrices. Generally, in South Africa, once the products containing these chemicals have outlived their usefulness, they are discarded into landfill sites. Consequently, the levels of PBDEs in leachates from landfill sites may give an indication of the general exposure and use of these compounds. The present study was aimed at determining the occurrence and concentrations of most common PBDEs in leachates from selected landfill sites. The extraction capacities of the solvents were also tested. Spiked landfill leachate samples were used for the recovery tests. Separation and determination of the PBDE congeners were carried out with a gas chromatograph equipped with Ni{sup 63} electron capture detector. The mean percentage recoveries ranged from 63% to 108% (n = 3) for landfill leachate samples with petroleum ether giving the highest percentage extraction. The mean concentrations of PBDEs obtained ranged from ND to 2670 pg l{sup -1}, ND to 6638 pg l{sup -1}, ND to 7230 pg l{sup -1}, 41 to 4009 pg l{sup -1}, 90 to 9793 pg l{sup -1} for the Garankuwa, Hatherly, Kwaggarsrand, Soshanguve and Temba landfill sites, respectively. Also BDE -28, -47, -71 and BDE-77 were detected in the leachate samples from all the landfill sites; and all the congeners were detected in two of the oldest landfill sites. The peak concentrations were recorded for BDE-47 at three sites and BDE-71 and BDE-75 at two sites. The highest concentration, 9793 {+-} 1.5 pg l{sup -1}, was obtained for the Temba landfill site with the highest BOD value. This may suggest some influence of organics on the level of PBDEs. Considering the leaching characteristics of brominated flame retardants, there is a high

  7. Thermal reactor. [liquid silicon production from silane gas

    NASA Technical Reports Server (NTRS)

    Levin, H.; Ford, L. B. (Inventor)

    1982-01-01

    A thermal reactor apparatus and method of pyrolyticaly decomposing silane gas into liquid silicon product and hydrogen by-product gas is disclosed. The thermal reactor has a reaction chamber which is heated well above the decomposition temperature of silane. An injector probe introduces the silane gas tangentially into the reaction chamber to form a first, outer, forwardly moving vortex containing the liquid silicon product and a second, inner, rewardly moving vortex containing the by-product hydrogen gas. The liquid silicon in the first outer vortex deposits onto the interior walls of the reaction chamber to form an equilibrium skull layer which flows to the forward or bottom end of the reaction chamber where it is removed. The by-product hydrogen gas in the second inner vortex is removed from the top or rear of the reaction chamber by a vortex finder. The injector probe which introduces the silane gas into the reaction chamber is continually cooled by a cooling jacket.

  8. Production of biodiesel using expanded gas solvents

    SciTech Connect

    Ginosar, Daniel M; Fox, Robert V; Petkovic, Lucia M

    2009-04-07

    A method of producing an alkyl ester. The method comprises providing an alcohol and a triglyceride or fatty acid. An expanding gas is dissolved into the alcohol to form a gas expanded solvent. The alcohol is reacted with the triglyceride or fatty acid in a single phase to produce the alkyl ester. The expanding gas may be a nonpolar expanding gas, such as carbon dioxide, methane, ethane, propane, butane, pentane, ethylene, propylene, butylene, pentene, isomers thereof, and mixtures thereof, which is dissolved into the alcohol. The gas expanded solvent may be maintained at a temperature below, at, or above a critical temperature of the expanding gas and at a pressure below, at, or above a critical pressure of the expanding gas.

  9. LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL

    SciTech Connect

    Don Augenstein; Ramin Yazdani; Rick Moore; Michelle Byars; Jeff Kieffer; Professor Morton Barlaz; Rinav Mehta

    2000-02-26

    Controlled landfilling is an approach to manage solid waste landfills, so as to rapidly complete methane generation, while maximizing gas capture and minimizing the usual emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated to more rapid and earlier completion to full potential by improving conditions (principally moisture, but also temperature) to optimize biological processes occurring within the landfill. Gas is contained through use of surface membrane cover. Gas is captured via porous layers, under the cover, operated at slight vacuum. A field demonstration project has been ongoing under NETL sponsorship for the past several years near Davis, CA. Results have been extremely encouraging. Two major benefits of the technology are reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times, more predictably, 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 both in reduction of US greenhouse gas emissions and in US renewable energy. The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 metric tons [tonnes]), sufficient to replicate many heat and compaction characteristics of larger ''full-scale'' landfills. An enhanced demonstration cell has received moisture supplementation to field capacity. This is the maximum moisture waste can hold while still limiting liquid drainage rate to minimal and safely manageable levels. The enhanced landfill module was compared to a parallel control landfill module receiving no moisture additions. Gas recovery has continued for a period of over 4 years. It is quite encouraging that the enhanced cell methane recovery has been close to 10-fold that experienced with conventional

  10. GASCAP: Wellhead Gas Productive Capacity Model documentation, June 1993

    SciTech Connect

    Not Available

    1993-07-01

    The Wellhead Gas Productive Capacity Model (GASCAP) has been developed by EIA to provide a historical analysis of the monthly productive capacity of natural gas at the wellhead and a projection of monthly capacity for 2 years into the future. The impact of drilling, oil and gas price assumptions, and demand on gas productive capacity are examined. Both gas-well gas and oil-well gas are included. Oil-well gas productive capacity is estimated separately and then combined with the gas-well gas productive capacity. This documentation report provides a general overview of the GASCAP Model, describes the underlying data base, provides technical descriptions of the component models, diagrams the system and subsystem flow, describes the equations, and provides definitions and sources of all variables used in the system. This documentation report is provided to enable users of EIA projections generated by GASCAP to understand the underlying procedures used and to replicate the models and solutions. This report should be of particular interest to those in the Congress, Federal and State agencies, industry, and the academic community, who are concerned with the future availability of natural gas.

  11. Biotic systems to mitigate landfill methane emissions.

    PubMed

    Huber-Humer, Marion; Gebert, Julia; Hilger, Helene

    2008-02-01

    Landfill gases produced during biological degradation of buried organic wastes include methane, which when released to the atmosphere, can contribute to global climate change. Increasing use of gas collection systems has reduced the risk of escaping methane emissions entering the atmosphere, but gas capture is not 100% efficient, and further, there are still many instances when gas collection systems are not used. Biotic methane mitigation systems exploit the propensity of some naturally occurring bacteria to oxidize methane. By providing optimum conditions for microbial habitation and efficiently routing landfill gases to where they are cultivated, a number of bio-based systems, such as interim or long-term biocovers, passively or actively vented biofilters, biowindows and daily-used biotarps, have been developed that can alone, or with gas collection, mitigate landfill methane emissions. This paper reviews the science that guides bio-based designs; summarizes experiences with the diverse natural or engineered substrates used in such systems; describes some of the studies and field trials being used to evaluate them; and discusses how they can be used for better landfill operation, capping, and aftercare.

  12. Advanced coal technology by-products: Long-term results from landfill test cells and their implications for reuse or disposal applications

    SciTech Connect

    Weinberg, A.; Harness, J.L.

    1994-06-01

    New air pollution regulations under the 1991 Clean Air Act and other legislation are motivating continued development and implementation, of cleaner, more efficient processes for converting coal to electrical power. These clean coal processes produce solid by-products which differ in important respects from conventional pulverized coal combustion ash. Clean coal by-products` contain both residual sorbent and captured SO{sub 2} control products, as well as the mineral component of the coal. The Department of Energy/Morgantown Energy Technology Center has contracted Radian Corporation to construct and monitor landfill test cells with a several different advanced coal combustion by-products at three locations around the US; data from these sites provide a unique picture of the long-term field behavior of clean coal combustion by-products. The field testing sites were located in western Colorado, northern Ohio, and central Illinois. Fluidized bed combustion and lime injection residues are characterized by high lime and calcium sulfate contents` contributed by reacted and unreacted sorbent materials, and produce an leachate, when wetted. Compared with conventional coal fly ash, the clean coal technology ashes have been noted for potential difficulties when wetted, including corrosivity, heat generation, cementation, and swelling on hydration. On the other hand, the high lime content and chemical reactivity of clean coal residues offer potential benefits in reuse as a cementitious material.The results of three years of data collection suggest a fairly consistent pattern of behavior for the calcium-based dry sorbent systems involved in the project, despite differences in the initial of the by-products, differences in the methods of placement, and differences in climate at the test sites.

  13. 78 FR 33051 - Notification of Proposed Production Activity, The Gas Company, LLC dba Hawai'i Gas, Subzone 9F...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-03

    ... Foreign-Trade Zones Board Notification of Proposed Production Activity, The Gas Company, LLC dba Hawai'i Gas, Subzone 9F (Synthetic Natural Gas), Kapolei, Hawaii The Gas Company, LLC dba Hawai'i Gas (Hawai'i Gas), operator of Subzone 9F, submitted a notification of proposed production activity to the...

  14. Mathematical analysis of intermittent gas injection model in oil production

    NASA Astrophysics Data System (ADS)

    Tasmi, Silvya, D. R.; Pudjo, S.; Leksono, M.; Edy, S.

    2016-02-01

    Intermittent gas injection is a method to help oil production process. Gas is injected through choke in surface and then gas into tubing. Gas forms three areas in tubing: gas column area, film area and slug area. Gas column is used to propel slug area until surface. A mathematical model of intermittent gas injection is developed in gas column area, film area and slug area. Model is expanding based on mass and momentum conservation. Using assume film thickness constant in tubing, model has been developed by Tasmi et. al. [14]. Model consists of 10 ordinary differential equations. In this paper, assumption of pressure in gas column is uniform. Model consist of 9 ordinary differential equations. Connection of several variables can be obtained from this model. Therefore, dynamics of all variables that affect to intermittent gas lift process can be seen from four equations. To study the behavior of variables can be analyzed numerically and mathematically. In this paper, simple mathematically analysis approach is used to study behavior of the variables. Variables that affect to intermittent gas injection are pressure in upstream valve and in gas column. Pressure in upstream valve will decrease when gas mass in valve greater than gas mass in choke. Dynamic of the pressure in the gas column will decrease and increase depending on pressure in upstream valve.

  15. Measuring micro-organism gas production

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Pearson, A. O.; Mills, S. M.

    1973-01-01

    Transducer, which senses pressure buildup, is easy to assemble and use, and rate of gas produced can be measured automatically and accurately. Method can be used in research, in clinical laboratories, and for environmental pollution studies because of its ability to detect and quantify rapidly the number of gas-producing microorganisms in water, beverages, and clinical samples.

  16. The new Waste Law: Challenging opportunity for future landfill operation in Indonesia.

    PubMed

    Meidiana, Christia; Gamse, Thomas

    2011-01-01

    The Waste Law No. 18/2008 Article 22 and 44 require the local governments to run environmentally sound landfill. Due to the widespread poor quality of waste management in Indonesia, this study aimed to identify the current situation by evaluating three selected landfills based on the ideal conditions of landfill practices, which are used to appraise the capability of local governments to adapt to the law. The results indicated that the local governments have problems of insufficient budget, inadequate equipment, uncollected waste and unplanned future landfill locations. All of the selected landfills were partially controlled landfills with open dumping practices predominating. In such inferior conditions the implementation of sanitary landfill is not necessarily appropriate. The controlled landfill is a more appropriate solution as it offers lower investment and operational costs, makes the selection of a new landfill site unnecessary and can operate with a minimum standard of infrastructure and equipment. The sustainability of future landfill capacity can be maintained by utilizing the old landfill as a profit-oriented landfill by implementing a landfill gas management or a clean development mechanism project. A collection fee system using the pay-as-you-throw principle could increase the waste income thereby financing municipal solid waste management. PMID:20935025

  17. Analysis of eastern Devonian gas shales production data

    SciTech Connect

    Gatens, J.M.; Stanley, D.K.; Lancaster, D.E.; Lee, W.J.; Lane, H.S.; Watson, A.T.

    1989-05-01

    Production data from more than 800 Devonian shale wells have been analyzed. Permeability-thickness product and gas in place estimated from production data have been found to correlate with well performance. Empirical performance equations, production type curves, and an analytical dual-porosity model with automatic history-matching scheme were developed for the Devonian shale.

  18. Depressurization and electrical heating of hydrate sediment for gas production

    NASA Astrophysics Data System (ADS)

    Minagawa, H.

    2015-12-01

    As a part of a Japanese National hydrate research program (MH21, funded by METI), we performed a study on electrical heating of the hydrate core combined with depressurization for gas production. In-situ dissociation of natural gas hydrate is necessary for commercial recovery of natural gas from natural gas hydrate sediment. Thermal stimulation is an effective dissociation method, along with depressurization.To simulate methane gas production from methane hydrate layer, we investigated electrical heating of methane hydrate sediment. A decrease in core temperature due to the endothermic reaction of methane hydrate dissociation was suppressed and the core temperature increased between 1oC and 4oC above the control temperature with electric heating. A current density of 10A/m2 with depressurization would effectively dissociate hydrate. Therefore, depressurization and additional electrode heating of hydrate sediment saturated with electrolyte solution was confirmed to enable higher gas production from sediment with less electric power.

  19. Integrated production of fuel gas and oxygenated organic compounds from synthesis gas

    DOEpatents

    Moore, Robert B.; Hegarty, William P.; Studer, David W.; Tirados, Edward J.

    1995-01-01

    An oxygenated organic liquid product and a fuel gas are produced from a portion of synthesis gas comprising hydrogen, carbon monoxide, carbon dioxide, and sulfur-containing compounds in a integrated feed treatment and catalytic reaction system. To prevent catalyst poisoning, the sulfur-containing compounds in the reactor feed are absorbed in a liquid comprising the reactor product, and the resulting sulfur-containing liquid is regenerated by stripping with untreated synthesis gas from the reactor. Stripping offgas is combined with the remaining synthesis gas to provide a fuel gas product. A portion of the regenerated liquid is used as makeup to the absorber and the remainder is withdrawn as a liquid product. The method is particularly useful for integration with a combined cycle coal gasification system utilizing a gas turbine for electric power generation.

  20. Bioreactor Landfill Research and Demonstration Project Northern Oaks Landfill, Harrison, MI

    SciTech Connect

    Zhao, Xiando; Voice, Thomas; and Hashsham, Syed A.

    2006-08-29

    A bioreactor landfill cell with 1.2-acre footprint was constructed, filled, operated, and monitored at Northern Oaks Recycling and Disposal Facility (NORDF) at Harrison, MI. With a filled volume of 74,239 cubic yards, the cell contained approximately 35,317 tons of municipal solid waste (MSW) and 20,777 tons of cover soil. It was laid on the slope of an existing cell but separated by a geosynthetic membrane liner. After the cell reached a design height of 60 feet, it was covered with a geosynthetic membrane cap. A three-dimensional monitoring system to collect data at 48 different locations was designed and installed during the construction phase of the bioreactor cell. Each location had a cluster of monitoring devices consisting of a probe to monitor moisture and temperature, a leachate collection basin, and a gas sampling port. An increase in moisture content of the MSW in the bioreactor cell was achieved by pumping leachate collected on-site from various other cells, as well as recirculation of leachate from the bioreactor landfill cell itself. Three types of leachate injection systems were evaluated in this bioreactor cell for their efficacy to distribute pumped leachate uniformly: a leachate injection pipe buried in a 6-ft wide horizontal stone mound, a 15-ft wide geocomposite drainage layer, and a 60-ft wide geocomposite drainage layer. All leachate injection systems were installed on top of the compacted waste surface. The distribution of water and resulting MSW moisture content throughout the bioreactor cell was found to be similar for the three designs. Water coming into and leaving the cell (leachate pumped in, precipitation, snow, evaporation, and collected leachate) was monitored in order to carry out a water balance. Using a leachate injection rate of 26 – 30 gal/yard3, the average moisture content increased from 25% to 35% (wet based) over the period of this study. One of the key aspects of this bioreactor landfill study was to evaluate bioreactor

  1. Method for the production of synthesis gas

    SciTech Connect

    Deuser, N.; Diemer, P.

    1982-09-28

    Crude gas obtained through partial oxidation of carboncontaining material is subjected to catalytic conversion in an apparatus containing a moistening-demoistering system connected by means of a combined water circulation. To reduce the required amount of steam and process heating, a partial stream of water coming from the moistener is branched off, heated by indirect heat exchange with converted, hot synthesis gas, and then united with the partial stream of water coming from the demoistener for re-delivery to the moistener.

  2. The influence of atmospheric pressure on landfill methane emissions.

    PubMed

    Czepiel, P M; Shorter, J H; Mosher, B; Allwine, E; McManus, J B; Harriss, R C; Kolb, C E; Lamb, B K

    2003-01-01

    Landfills are the largest source of anthropogenic methane (CH4) emissions to the atmosphere in the United States. However, few measurements of whole landfill CH4 emissions have been reported. Here, we present the results of a multi-season study of whole landfill CH4 emissions using atmospheric tracer methods at the Nashua, New Hampshire Municipal landfill in the northeastern United States. The measurement data include 12 individual emission tests, each test consisting of 5-8 plume measurements. Measured emissions were negatively correlated with surface atmospheric pressure and ranged from 7.3 to 26.5 m3 CH4 min(-1). A simple regression model of our results was used to calculate an annual emission rate of 8.4 x 10(6) m3 CH4 year(-1). These data, along with CH4 oxidation estimates based on emitted landfill gas isotopic characteristics and gas collection data, were used to estimate annual CH4 generation at this landfill. A reported gas collection rate of 7.1 x 10(6) m3 CH4 year(-1) and an estimated annual rate of CH4 oxidation by cover soils of 1.2 x 10(6) m3 CH4 year(-1) resulted in a calculated annual CH4 generation rate of 16.7 x 10(6) m3 CH4 year(-1). These results underscore the necessity of understanding a landfill's dynamic environment before assessing long-term emissions potential.

  3. Subsurface interactions of Fe(II) with humic acid or landfill leachate do not control subsequent iron(III) (hydr)oxide production at the surface.

    PubMed

    Jackson, Alison; Gaffney, John W; Boult, Stephen

    2012-07-17

    At least 93% of Fe(II) remained free, as defined by ferrozine assay under anoxic conditions in the presence of humic acid (HA) and two simulated landfill leachates of different maturities. However, tangential flow ultrafiltration showed a weaker but more extensive interaction of Fe with organic carbon (OC); 90% of Fe associated with the less mature leachate. Despite the existence of this weak interaction under anoxic conditions, there was no difference in iron(III) (hydr)oxide production whether HA was added prior to or coincident with the oxidation of Fe(II) on exposure to oxic conditions. Under oxic conditions ferrozine showed that more Fe(II) bound to OC, up to 50% to HA. However, this occurs via oxidation of Fe(II) to Fe(III), which is bound and then thermally reduced. This affinity for Fe(III) and the ability to carry out thermal reduction both increase with the maturity of the OC. The rate at which ferrozine-defined free Fe(II) was lost on exposure to dissolved oxygen was also enhanced by the more mature OC, while it was slowed by acetogenic leachate. The slowing must be a consequence of the filtration-defined Fe(II)/OC interaction.

  4. Anaerobic co-digestion of wine/fruit-juice production waste with landfill leachate diluted municipal sludge cake under semi-continuous flow operation.

    PubMed

    Leiva, M Barrantes; Koupaie, E Hosseini; Eskicioglu, C

    2014-10-01

    Anaerobic co-digestion of four organic waste streams; a thickened waste activated sludge (TWAS) and screen cake (SC) from a fruit-juice/winery wastewater treatment plant along with municipal sludge cake (MC) and landfill leachate (LL) was evaluated. A total of eight semi-continuously-fed single and co-digesters were operated side-by-side at sludge retention times (SRT) of 20 and 10 days. Co-digestion of industrial waste streams (TWAS and SC) with MC and LL resulted in increased operational stability compared to the single digestion of industrial TWAS at the higher organic loading (10 d SRT). Although digester operational temperature had no statistically significant effect on organics removal and biogas production, mesophilic digesters had consistently higher total coliform densities (8838-37,959 most probable number or MPN/g-dry weight) compared to the thermophilic digesters (41-6723 MPN/g-dry weight) at both SRTs. Coliform analysis results also proved that most of the thermophilic digestates could be classified as Class A biosolids according to regulations. Furthermore, addition of industrial TWAS to co-digesters enhanced the dewaterability of the digested streams. A cost-benefit analysis confirmed the benefits and indicated that a full-scale co-digester utilizing all four waste streams can decrease the total capital and operational cost by 22% ($10.52 million). PMID:25081853

  5. Global Biogenic Emission of Carbon Dioxide from Landfills

    NASA Astrophysics Data System (ADS)

    Lima, R.; Nolasco, D.; Meneses, W.; Salazar, J.; Hernández, P.; Pérez, N.

    2002-12-01

    Human-induced increases in the atmospheric concentrations of greenhouse gas components have been underway over the past century and are expected to drive climate change in the coming decades. Carbon dioxide was responsible for an estimated 55 % of the antropogenically driven radiactive forcing of the atmosphere in the 1980s and is predicted to have even greater importance over the next century (Houghton et al., 1990). A highly resolved understanding of the sources and sinks of atmospheric CO2, and how they are affected by climate and land use, is essential in the analysis of the global carbon cycle and how it may be impacted by human activities. Landfills are biochemical reactors that produce CH4 and CO2 emissions due to anaerobic digestion of solid urban wastes. Estimated global CH4 emission from landfills is about 44 millions tons per year and account for a 7.4 % of all CH4 sources (Whiticar, 1989). Observed CO2/CH4 molar ratios from landfill gases lie within the range of 0.7-1.0; therefore, an estimated global biogenic emission of CO2 from landfills could reach levels of 11.2-16 millions tons per year. Since biogas extraction systems are installed for extracting, purifying and burning the landfill gases, most of the biogenic gas emission to the atmosphere from landfills occurs through the surface environment in a diffuse and disperse form, also known as non-controlled biogenic emission. Several studies of non-controlled biogenic gas emission from landfills showed that CO2/CH4 weight ratios of surface landfill gases, which are directly injected into the atmosphere, are about 200-300 times higher than those observed in the landfill wells, which are usually collected and burned by gas extraction systems. This difference between surface and well landfill gases is mainly due to bacterial oxidation of the CH4 to CO2 inducing higher CO2/CH4 ratios for surface landfill gases than those well landfill gases. Taking into consideration this observation, the global biogenic

  6. Assessment of the methane oxidation capacity of compacted soils intended for use as landfill cover materials

    SciTech Connect

    Rachor, Ingke; Gebert, Julia; Groengroeft, Alexander; Pfeiffer, Eva-Maria

    2011-05-15

    The microbial oxidation of methane in engineered cover soils is considered a potent option for the mitigation of emissions from old landfills or sites containing wastes of low methane generation rates. A laboratory column study was conducted in order to derive design criteria that enable construction of an effective methane oxidising cover from the range of soils that are available to the landfill operator. Therefore, the methane oxidation capacity of different soils was assessed under simulated landfill conditions. Five sandy potential landfill top cover materials with varying contents of silt and clay were investigated with respect to methane oxidation and corresponding soil gas composition over a period of four months. The soils were compacted to 95% of their specific proctor density, resulting in bulk densities of 1.4-1.7 g cm{sup -3}, reflecting considerably unfavourable conditions for methane oxidation due to reduced air-filled porosity. The soil water content was adjusted to field capacity, resulting in water contents ranging from 16.2 to 48.5 vol.%. The investigated inlet fluxes ranged from 25 to about 100 g CH{sub 4} m{sup -2} d{sup -1}, covering the methane load proposed to allow for complete oxidation in landfill covers under Western European climate conditions and hence being suggested as a criterion for release from aftercare. The vertical distribution of gas concentrations, methane flux balances as well as stable carbon isotope studies allowed for clear process identifications. Higher inlet fluxes led to a reduction of the aerated zone, an increase in the absolute methane oxidation rate and a decline of the relative proportion of oxidized methane. For each material, a specific maximum oxidation rate was determined, which varied between 20 and 95 g CH{sub 4} m{sup -2} d{sup -1} and which was positively correlated to the air-filled porosity of the soil. Methane oxidation efficiencies and gas profile data imply a strong link between oxidation capacity

  7. Gas hearth products market fact base. Topical report, January 1996

    SciTech Connect

    1996-02-01

    The Gas Hearth Products Market Fact Base is an analysis of the U.S. gas log and fireplace markets. The study was undertaken to: determine current usage of and attitudes about fireplaces; identify barriers to acceptance of gas logs and fireplaces; determine the influence of service providers, and; identify important trends that can affect the markets for gas hearth products. The market fact base is based on four studies: a market analysis synthesizing primary and secondary research reports; in-depth interviews with market influencers from across the country (architects, contractors, interior designers, fireplace retailers and installers) and industry experts from gas utilities and trade associations; focus group meetings with consumers who own or intend to buy fireplaces, gas fireplace industry professionals, and editors of fireplace-related trade magazines, and; quantitative interviews with consumers in six U.S. cities.

  8. Process for production desulfurized of synthesis gas

    DOEpatents

    Wolfenbarger, James K.; Najjar, Mitri S.

    1993-01-01

    A process for the partial oxidation of a sulfur- and silicate-containing carbonaceous fuel to produce a synthesis gas with reduced sulfur content which comprises partially oxidizing said fuel at a temperature in the range of 1900.degree.-2600.degree. F. in the presence of a temperature moderator, an oxygen-containing gas and a sulfur capture additive which comprises a calcium-containing compound portion, a sodium-containing compound portion, and a fluoride-containing compound portion to produce a synthesis gas comprising H.sub.2 and CO with a reduced sulfur content and a molten slag which comprises (1) a sulfur-containing sodium-calcium-fluoride silicate phase; and (2) a sodium-calcium sulfide phase.

  9. Separation of flue-gas scrubber sludge into marketable products. First quarterly technical progress report, 1 September, 1993--30 November, 1993

    SciTech Connect

    Kawatra, S.K.; Eisele, T.C.; Shoop, K.

    1993-12-01

    To reduce their sulfur emissions, many coal-fired electric power plants use wet flue-gas scrubbers. These scrubbers convert sulfur oxides into solid sulfate and sulfite sludge, which must then be disposed of. The vast majority of the sludge is simply landfilled, but with increasing landfilling costs this can cost the plant millions of dollars per year. Producing marketable materials from the sludge is a far more promising avenue, provided that the products can meet the necessary specifications at a reasonable cost. This project is investigating the surface properties of scrubber sludge, particularly of the calcium sulfite, since the surface chemistry of this material has never been studied in detail. Knowledge of these properties is critical for the development of a process that can produce a high-quality calcium sulfite or gypsum product while keeping process costs low enough that the material produced will be competitive with that from other, more conventional sources. This purification will consist of minimal-reagent froth flotation, using the surface properties of the particles of unreacted limestone to remove them and their associated impurities from the material, leaving a purified gypsum or calcium sulfite product. The separated limestone will be a useful by-product, as it can be recycled to the scrubber, thus boosting the limestone utilization and improving process efficiency. Calcium sulfite will then be oxidized to gypsum, or separated as a salable product in its own right from sludges where it is present in sufficient quantity. The main product of the process will be either gypsum or calcium sulfite, depending on the characteristics of the sludge being processed. These products will be sufficiently pure to be easily marketed, rather than being landfilled.

  10. Pilot-scale experiment on anaerobic bioreactor landfills in China

    SciTech Connect

    Jiang, Jianguo Yang, Guodong; Deng, Zhou; Huang, Yunfeng; Huang, Zhonglin; Feng, Xiangming; Zhou, Shengyong; Zhang, Chaoping

    2007-07-01

    Developing countries have begun to investigate bioreactor landfills for municipal solid waste management. This paper describes the impacts of leachate recirculation and recirculation loadings on waste stabilization, landfill gas (LFG) generation and leachate characteristics. Four simulated anaerobic columns, R1-R4, were each filled with about 30 tons of waste and recirculated weekly with 1.6, 0.8 and 0.2 m{sup 3} leachate and 0.1 m{sup 3} tap water. The results indicated that the chemical oxygen demand (COD) half-time of leachate from R1 was about 180 days, which was 8-14 weeks shorter than that of R2-R4. A large amount of LFG was first produced in R1, and its generation rate was positively correlated to the COD or volatile fatty acid concentrations of influent leachates after the 30th week. By the 50th week of recirculation, the waste in R1 was more stabilized, with 931.2 kg COD or 175.6 kg total organic carbon released and with the highest landfill gas production. However, this contributed mainly to washout by leachate, which also resulted in the reduction of LFG generation potential and accumulation of ammonia and/or phosphorus in the early stage. Therefore, the regimes of leachate recirculation should be adjusted to the phases of waste stabilization to enhance efficiency of energy recovery. Integrated with the strategy of in situ leachate management, extra pre-treatment or post-treatment methods to remove the nutrients are recommended.

  11. Strategies for gas production from oceanic Class 3 hydrateaccumulations

    SciTech Connect

    Moridis, George J.; Reagan, Matthew T.

    2007-05-01

    Gas hydrates are solid crystalline compounds in which gasmolecules are lodged within the lattices of ice crystals. Vast amounts ofCH4 are trapped in gas hydrates, and a significant effort has recentlybegun to evaluate hydrate deposits as a potential energy source. Class 3hydrate deposits are characterized by an isolated Hydrate-Bearing Layer(HBL) that is not in contact with any hydrate-free zone of mobile fluids.The base of the HBL in Class 3 deposits may occur within or at the edgeof the zone of thermodynamic hydrate stability.In this numerical study oflong-term gas production from typical representatives of unfracturedClass 3 deposits, we determine that simple thermal stimulation appears tobe a slow and inefficient production method. Electrical heating and warmwater injection result in very low production rates (4 and 12 MSCFD,respectively) that are orders of magnitude lower than generallyacceptable standards of commercial viability of gas production fromoceanic reservoirs. However, production from depressurization-baseddissociation based on a constant well pressure appears to be a promisingapproach even in deposits characterized by high hydrate saturations. Thisapproach allows the production of very large volumes ofhydrate-originating gas at high rates (>15 MMSCFD, with a long-termaverage of about 8.1 MMSCFD for the reference case) for long times usingconventional technology. Gas production from hydrates is accompanied by asignificant production of water. However, unlike conventional gasreservoirs, the water production rate declines with time. The lowsalinity of the produced water may require care in its disposal. Becauseof the overwhelming advantage of depressurization-based methods, thesensitivity analysis was not extendedto thermal stimulation methods. Thesimulation results indicate that depressurization-induced gas productionfrom oceanic Class 3 deposits increases (and the corresponding waterto-gas ratio decreases) with increasing hydrate temperature

  12. Tempest gas turbine extends EGT product line

    SciTech Connect

    Chellini, R.

    1995-07-01

    With the introduction of the 7.8 MW (mechanical output) Tempest gas turbine, ECT has extended the company`s line of its small industrial turbines. The new Tempest machine, featuring a 7.5 MW electric output and a 33% thermal efficiency, ranks above the company`s single-shaft Typhoon gas turbine, rated 3.2 and 4.9 MW, and the 6.3 MW Tornado gas turbine. All three machines are well-suited for use in combined heat and power (CHP) plants, as demonstrated by the fact that close to 50% of the 150 Typhoon units sold are for CHP applications. This experience has induced EGT, of Lincoln, England, to announce the introduction of the new gas turbine prior to completion of the testing program. The present single-shaft machine is expected to be used mainly for industrial trial cogeneration. This market segment, covering the needs of paper mills, hospitals, chemical plants, ceramic industry, etc., is a typical local market. Cogeneration plants are engineered according to local needs and have to be assisted by local organizations. For this reason, to efficiently cover the world market, EGT has selected a number of associates that will receive from Lincoln completely engineered machine packages and will engineer the cogeneration system according to custom requirements. These partners will also assist the customer and dispose locally of the spares required for maintenance operations.

  13. Recirculation of reverse osmosis concentrate in lab-scale anaerobic and aerobic landfill simulation reactors.

    PubMed

    Morello, Luca; Cossu, Raffaello; Raga, Roberto; Pivato, Alberto; Lavagnolo, Maria Cristina

    2016-10-01

    Leachate treatment is a major issue in the context of landfill management, particularly in view of the consistent changes manifested over time in the quality and quantity of leachate produced, linked to both waste and landfill characteristics, which renders the procedure technically difficult and expensive. Leachate recirculation may afford a series of potential advantages, including improvement of leachate quality, enhancement of gas production, acceleration of biochemical processes, control of moisture content, as well as nutrients and microbe migration within the landfill. Recirculation of the products of leachate treatment, such as reverse osmosis (RO) concentrate, is a less common practice, with widespread controversy relating to its suitability, potential impacts on landfill management and future gaseous and leachable emissions. Scientific literature provides the results of only a few full-scale applications of concentrate recirculation. In some cases, an increase of COD and ammonium nitrogen in leachate was observed, coupled with an increase of salinity; which, additionally, might negatively affect performance of the RO plant itself. In other cases, not only did leachate production not increase significantly but the characteristics of leachate extracted from the well closest to the re-injection point also remained unchanged. This paper presents the results of lab-scale tests conducted in landfill simulation reactors, in which the effects of injection of municipal solid waste (MSW) landfill leachate RO concentrate were evaluated. Six reactors were managed with different weekly concentrate inputs, under both anaerobic and aerobic conditions, with the aim of investigating the short and long-term effects of this practice on landfill emissions. Lab-scale tests resulted in a more reliable identification of compound accumulation and kinetic changes than full-scale applications, further enhancing the development of a mass balance in which gaseous emissions and waste

  14. Recirculation of reverse osmosis concentrate in lab-scale anaerobic and aerobic landfill simulation reactors.

    PubMed

    Morello, Luca; Cossu, Raffaello; Raga, Roberto; Pivato, Alberto; Lavagnolo, Maria Cristina

    2016-10-01

    Leachate treatment is a major issue in the context of landfill management, particularly in view of the consistent changes manifested over time in the quality and quantity of leachate produced, linked to both waste and landfill characteristics, which renders the procedure technically difficult and expensive. Leachate recirculation may afford a series of potential advantages, including improvement of leachate quality, enhancement of gas production, acceleration of biochemical processes, control of moisture content, as well as nutrients and microbe migration within the landfill. Recirculation of the products of leachate treatment, such as reverse osmosis (RO) concentrate, is a less common practice, with widespread controversy relating to its suitability, potential impacts on landfill management and future gaseous and leachable emissions. Scientific literature provides the results of only a few full-scale applications of concentrate recirculation. In some cases, an increase of COD and ammonium nitrogen in leachate was observed, coupled with an increase of salinity; which, additionally, might negatively affect performance of the RO plant itself. In other cases, not only did leachate production not increase significantly but the characteristics of leachate extracted from the well closest to the re-injection point also remained unchanged. This paper presents the results of lab-scale tests conducted in landfill simulation reactors, in which the effects of injection of municipal solid waste (MSW) landfill leachate RO concentrate were evaluated. Six reactors were managed with different weekly concentrate inputs, under both anaerobic and aerobic conditions, with the aim of investigating the short and long-term effects of this practice on landfill emissions. Lab-scale tests resulted in a more reliable identification of compound accumulation and kinetic changes than full-scale applications, further enhancing the development of a mass balance in which gaseous emissions and waste

  15. Molecular Analysis of Methanogen Richness in Landfill and Marshland Targeting 16S rDNA Sequences.

    PubMed

    Yadav, Shailendra; Kundu, Sharbadeb; Ghosh, Sankar K; Maitra, S S

    2015-01-01

    Methanogens, a key contributor in global carbon cycling, methane emission, and alternative energy production, generate methane gas via anaerobic digestion of organic matter. The methane emission potential depends upon methanogenic diversity and activity. Since they are anaerobes and difficult to isolate and culture, their diversity present in the landfill sites of Delhi and marshlands of Southern Assam, India, was analyzed using molecular techniques like 16S rDNA sequencing, DGGE, and qPCR. The sequencing results indicated the presence of methanogens belonging to the seventh order and also the order Methanomicrobiales in the Ghazipur and Bhalsawa landfill sites of Delhi. Sequences, related to the phyla Crenarchaeota (thermophilic) and Thaumarchaeota (mesophilic), were detected from marshland sites of Southern Assam, India. Jaccard analysis of DGGE gel using Gel2K showed three main clusters depending on the number and similarity of band patterns. The copy number analysis of hydrogenotrophic methanogens using qPCR indicates higher abundance in landfill sites of Delhi as compared to the marshlands of Southern Assam. The knowledge about "methanogenic archaea composition" and "abundance" in the contrasting ecosystems like "landfill" and "marshland" may reorient our understanding of the Archaea inhabitants. This study could shed light on the relationship between methane-dynamics and the global warming process. PMID:26568700

  16. Molecular Analysis of Methanogen Richness in Landfill and Marshland Targeting 16S rDNA Sequences.

    PubMed

    Yadav, Shailendra; Kundu, Sharbadeb; Ghosh, Sankar K; Maitra, S S

    2015-01-01

    Methanogens, a key contributor in global carbon cycling, methane emission, and alternative energy production, generate methane gas via anaerobic digestion of organic matter. The methane emission potential depends upon methanogenic diversity and activity. Since they are anaerobes and difficult to isolate and culture, their diversity present in the landfill sites of Delhi and marshlands of Southern Assam, India, was analyzed using molecular techniques like 16S rDNA sequencing, DGGE, and qPCR. The sequencing results indicated the presence of methanogens belonging to the seventh order and also the order Methanomicrobiales in the Ghazipur and Bhalsawa landfill sites of Delhi. Sequences, related to the phyla Crenarchaeota (thermophilic) and Thaumarchaeota (mesophilic), were detected from marshland sites of Southern Assam, India. Jaccard analysis of DGGE gel using Gel2K showed three main clusters depending on the number and similarity of band patterns. The copy number analysis of hydrogenotrophic methanogens using qPCR indicates higher abundance in landfill sites of Delhi as compared to the marshlands of Southern Assam. The knowledge about "methanogenic archaea composition" and "abundance" in the contrasting ecosystems like "landfill" and "marshland" may reorient our understanding of the Archaea inhabitants. This study could shed light on the relationship between methane-dynamics and the global warming process.

  17. Outer Continental Shelf Oil and Gas Leasing/Production Program

    SciTech Connect

    Not Available

    1988-01-01

    This annual report on the Outer Continental Shelf (OCS) Oil and Gas Leasing and Production program summarizes receipts and expenditures, and includes information on OCS safety violations as reported by the US Coast Guard. 3 figs., 12 tabs.

  18. Clean Air Act Title III accidental emission release risk management program, and how it applies to landfills

    SciTech Connect

    Hibbard, C.S.

    1999-07-01

    On June 20, 1996, EPA promulgated regulations pursuant to Title III of the Clean Air Act (CAA) Amendments of 1990 (Section 112(r)(7) of the CAA). The rule, contained in 40 CFR Part 68, is called Accidental Release Prevention Requirements: Risk Management Programs, and is intended to improve accident prevention and emergency response practices at facilities that store and/or use hazardous substances. Methane is a designated highly hazardous chemical (HHC) under the rule. The rule applies to facilities that have 10,000 pounds of methane or more in any process, roughly equivalent to about 244,000 cubic feet of methane. The US EPA has interpreted this threshold quantity as applying to landfill gas within landfills. This paper presents an overview of the Accidental Release Prevention regulations, and how landfills are affected by the requirements. This paper describes methodologies for calculating the threshold quantity of landfill gas in a landfill. Methane is in landfill gas as a mixture. Because landfill gas can burn readily, down to concentrations of about five percent methane, the entire landfill gas mixture must be treated as the regulated substance, and counts toward the 10,000-pound threshold. It is reasonable to assume that the entire landfill gas collection system, active or passive, is filled with landfill gas, and that a calculation of the volume of the system would be a calculation of the landfill gas present in the process on the site. However, the US EPA has indicated that there are some instances in which pore space gas should be included in this calculation. This paper presents methods available to calculate the amount of pore space gas in a landfill, and how to determine how much of that gas might be available for an explosion. The paper goes through how to conduct the release assessment to determine the worst-case hazard zone around the landfill.

  19. Preliminary report on the commercial viability of gas production from natural gas hydrates

    USGS Publications Warehouse

    Walsh, M.R.; Hancock, S.H.; Wilson, S.J.; Patil, S.L.; Moridis, G.J.; Boswell, R.; Collett, T.S.; Koh, C.A.; Sloan, E.D.

    2009-01-01

    Economic studies on simulated gas hydrate reservoirs have been compiled to estimate the price of natural gas that may lead to economically viable production from the most promising gas hydrate accumulations. As a first estimate, $CDN2005 12/Mscf is the lowest gas price that would allow economically viable production from gas hydrates in the absence of associated free gas, while an underlying gas deposit will reduce the viability price estimate to $CDN2005 7.50/Mscf. Results from a recent analysis of the simulated production of natural gas from marine hydrate deposits are also considered in this report; on an IROR basis, it is $US2008 3.50-4.00/Mscf more expensive to produce marine hydrates than conventional marine gas assuming the existence of sufficiently large marine hydrate accumulations. While these prices represent the best available estimates, the economic evaluation of a specific project is highly dependent on the producibility of the target zone, the amount of gas in place, the associated geologic and depositional environment, existing pipeline infrastructure, and local tariffs and taxes. ?? 2009 Elsevier B.V.

  20. The estimation of methane emissions from landfills with different cover systems

    NASA Astrophysics Data System (ADS)

    Park, S.; Lee, K.; Sung, K.

    2006-12-01

    Methane is a very potent greenhouse gas, second only to CO2 as an anthropogenic contributor to global warming. Landfills are important anthropogenic source in the CH4 emissions. Microbially mediated CH4 oxidation in landfills with conventional soil covers can serve as an efficient biological sink. Methane from modern sanitary landfills equipped with composite covers and gas collection system is vented directly to the atmosphere, except for some of the largest landfills at which it is collected and burned. However, previous laboratory research has shown that biofilters have the potential to reduce CH4 emissions from landfills with modern composite covers. In this study a CH4 emission model was developed. The model used the calculated CH4 oxidation rates to estimate CH4 emissions from landfills constructed with conventional soil covers, modern composite covers, and modern composite covers plus biofilters. According to the CH4 emission rates predicted by CH4 emission model, it was estimated that 90% of the generated CH4 was emitted to the atmosphere for landfills with modern composite cover. For landfills with modern composite cover plus biofilters, an average of only 9% of the generated CH4 was estimated to be emitted. For landfills with conventional covers, an average of 83% of the generated CH4 was estimated to be emitted. By comparing the CH4 emission rates from three different landfill types, the use of a properly managed biofilter should be an effective technique to reduce CH4 emissions from landfills.

  1. Quantification of landfill emissions to air: a case study of the Ano Liosia landfill site in the greater Athens area.

    PubMed

    Paraskaki, Ioanna; Lazaridis, Mihalis

    2005-06-01

    Fugitive pollutant emissions from municipal solid waste landfills have the potential to cause annoyance and health impacts in the surrounding residential areas. The overall objective of this research was to perform an assessment of fugitive pollutant emissions and a dispersion analysis downwind of a specific landfill site. The study was performed at the closed Ano Liosia landfill site which is located in the greater Athens area. The human exposure from priority to health-risk pollutants emitted from landfill, such as vinyl chloride and benzene, was estimated by the landfill gas emission LandGEM 2.01 software combined with the atmospheric long-term dispersion model ISC3-LT. The emission and meteorological conditions under which the models were applied referred to the worst-case scenario. This scenario was used for the evaluation of the maximum human exposure assessed beyond the Ano Liosia landfill towards the residential areas. The above scenario provides the minimum downwind distance of the health-risk zone which is calculated to be equal to 1.5 km from the landfill. Within this distance the assessed air pollutant concentration for several air pollutants was significantly above the World Health Organization reference lifetime exposure health criteria. Finally, the applied methodology was used in the Ano Liosia landfill, where atmospheric concentrations of pollutants measured in the field were compared with model predictions. PMID:15997481

  2. Quantification of landfill emissions to air: a case study of the Ano Liosia landfill site in the greater Athens area.

    PubMed

    Paraskaki, Ioanna; Lazaridis, Mihalis

    2005-06-01

    Fugitive pollutant emissions from municipal solid waste landfills have the potential to cause annoyance and health impacts in the surrounding residential areas. The overall objective of this research was to perform an assessment of fugitive pollutant emissions and a dispersion analysis downwind of a specific landfill site. The study was performed at the closed Ano Liosia landfill site which is located in the greater Athens area. The human exposure from priority to health-risk pollutants emitted from landfill, such as vinyl chloride and benzene, was estimated by the landfill gas emission LandGEM 2.01 software combined with the atmospheric long-term dispersion model ISC3-LT. The emission and meteorological conditions under which the models were applied referred to the worst-case scenario. This scenario was used for the evaluation of the maximum human exposure assessed beyond the Ano Liosia landfill towards the residential areas. The above scenario provides the minimum downwind distance of the health-risk zone which is calculated to be equal to 1.5 km from the landfill. Within this distance the assessed air pollutant concentration for several air pollutants was significantly above the World Health Organization reference lifetime exposure health criteria. Finally, the applied methodology was used in the Ano Liosia landfill, where atmospheric concentrations of pollutants measured in the field were compared with model predictions.

  3. Carbonyl Emissions From Oil and Gas Production Facilities

    NASA Astrophysics Data System (ADS)

    Lyman, S. N.; O'Neil, T.; Tran, T.

    2015-12-01

    A number of recent studies have targeted emissions of methane and other hydrocarbons from oil and gas exploration and production activity. These measurements are greatly increasing understanding of the atmospheric impacts of oil and gas development. Very few measurements exist, however, of emissions of formaldehyde and other carbonyls from oil and gas equipment. Carbonyls are toxic and serve as important ozone precursors, especially during winter ozone episodes in places like Utah's Uintah Basin. Current air quality models are only able to reproduce observed high wintertime ozone if they incorporate emissions inventories with very high carbonyl emissions. We measured carbonyl emissions from oil and gas equipment and facilities—including glycol dehydrators, liquid storage tanks, raw gas leaks, raw gas-burning engines, and produced water surface impoundments—in Rocky Mountain oil and gas fields. Carbonyl emissions from raw gas were below detection, but emissions of formaldehyde, acetaldehyde, and other carbonyls were detected from liquid storage tanks, glycol dehydrators, and other oil and gas equipment. In some cases, carbonyls may be formed from the degradation of methanol and other chemicals used in oil and gas production, but the collected data provide evidence for other non-combustion formation pathways. Raw gas-burning engines also emitted carbonyls. Emissions from all measured sources were a small fraction of total volatile organic compound emissions. We incorporated our measurements into an emissions inventory, used that inventory in an air quality model (WRF-SMOKE-CAMx), and were unable to reproduce observed high wintertime ozone. This could be because (1) emission sources we have not yet measured, including compressors, gas processing plants, and others, are large; (2) non-carbonyl emissions, especially those that quickly degrade into carbonyls during photochemical processing, are underestimated in the inventory; or (3) the air quality model is unable

  4. Challenges, uncertainties and issues facing gas production from gas hydrate deposits

    SciTech Connect

    Moridis, G.J.; Collett, T.S.; Pooladi-Darvish, M.; Hancock, S.; Santamarina, C.; Boswell, R.; Kneafsey, T.; Rutqvist, J.; Kowalsky, M.; Reagan, M.T.; Sloan, E.D.; Sum, A.K.; Koh, C.

    2010-11-01

    The current paper complements the Moridis et al. (2009) review of the status of the effort toward commercial gas production from hydrates. We aim to describe the concept of the gas hydrate petroleum system, to discuss advances, requirement and suggested practices in gas hydrate (GH) prospecting and GH deposit characterization, and to review the associated technical, economic and environmental challenges and uncertainties, including: the accurate assessment of producible fractions of the GH resource, the development of methodologies for identifying suitable production targets, the sampling of hydrate-bearing sediments and sample analysis, the analysis and interpretation of geophysical surveys of GH reservoirs, well testing methods and interpretation of the results, geomechanical and reservoir/well stability concerns, well design, operation and installation, field operations and extending production beyond sand-dominated GH reservoirs, monitoring production and geomechanical stability, laboratory investigations, fundamental knowledge of hydrate behavior, the economics of commercial gas production from hydrates, and the associated environmental concerns.

  5. Quantifying Methane Abatement Efficiency at Three Municipal Solid Waste Landfills; Final Report

    EPA Science Inventory

    Measurements were conducted at three municipal solid waste landfills to compare fugitive methane emissions from the landfill cells to the quantity of collected gas (i.e., gas collection efficiency). The measurements were conducted over a multi-week sampling campaign using EPA Oth...

  6. Biotic landfill cover treatments for mitigating methane emissions.

    PubMed

    Hilgeri, Helene; Humer, Marion

    2003-05-01

    Landfill methane (CH4) emissions have been cited as one of the anthropogenic gas releases that can and should be controlled to reduce global climate change. This article reviews recent research that identifies ways to enhance microbial consumption of the gas in the aerobic portion of a landfill cover. Use of these methods can augment CH4 emission reductions achieved by gas collection or provide a sole means to consume CH4 at small landfills that do not have active gas collection systems. Field studies indicate that high levels of CH4 removal can be achieved by optimizing natural soil microbial processes. Further, during biotic conversion, not all of the CH4 carbon is converted to carbon dioxide (CO2) gas and released to the atmosphere; some of it will be sequestered in microbial biomass. Because biotic covers can employ residuals from other municipal processes, financial benefits can also accrue from avoided costs for residuals disposal.

  7. Methods of Sensing Land Pollution from Sanitary Landfills

    NASA Technical Reports Server (NTRS)

    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.

  8. Municipal landfill leachate management

    SciTech Connect

    Kusterer, T.; Willson, R.; Bruce, S.C.; Tissue, E. Lou, P.J.

    1998-12-31

    From 1995 to 1997, the Montgomery County Leachate Pretreatment Facility (MCLPF) has successfully pretreated in excess of 18,000,000 gallons of leachate generated by the county`s municipal solid waste landfill. The collection system directs leachate from the original landfill. The collection system directs leachate from the original landfill, the new lined section, and the ash cell to the leachate pump station. The leachate, prior to being pumped to the leachate pretreatment system, is equalized in two storage lagoons with a combined capacity of more than 5,000,000 gallons. The innovative leachate treatment system, incorporating a biological reactor system equipped with a submerged fixed-film reactor using a patented Matrix Biological Film (MBF) media, continues to provide excellent pretreatment results for the leachate generated at the Oaks Landfill in Montgomery County, Maryland. In 1995 and 1996, the system responded to the substantial challenges imposed by the changing characteristics of the material being landfilled and by the significant amounts of incinerator ash, received in 1995 from the county`s resource recovery facility (RRF), which influenced the influent leachate characteristics.

  9. Washing of waste prior to landfilling.

    PubMed

    Cossu, Raffaello; Lai, Tiziana

    2012-05-01

    The main impact produced by landfills is represented by the release of leachate emissions. Waste washing treatment has been investigated to evaluate its efficiency in reducing the waste leaching fraction prior to landfilling. The results of laboratory-scale washing tests applied to several significant residues from integrated management of solid waste are presented in this study, specifically: non-recyclable plastics from source separation, mechanical-biological treated municipal solid waste and a special waste, automotive shredded residues. Results obtained demonstrate that washing treatment contributes towards combating the environmental impacts of raw wastes. Accordingly, a leachate production model was applied, leading to the consideration that the concentrations of chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN), parameters of fundamental importance in the characterization of landfill leachate, from a landfill containing washed wastes, are comparable to those that would only be reached between 90 and 220years later in the presence of raw wastes. The findings obtained demonstrated that washing of waste may represent an effective means of reducing the leachable fraction resulting in a consequent decrease in landfill emissions. Further studies on pilot scale are needed to assess the potential for full-scale application of this treatment.

  10. Washing of waste prior to landfilling.

    PubMed

    Cossu, Raffaello; Lai, Tiziana

    2012-05-01

    The main impact produced by landfills is represented by the release of leachate emissions. Waste washing treatment has been investigated to evaluate its efficiency in reducing the waste leaching fraction prior to landfilling. The results of laboratory-scale washing tests applied to several significant residues from integrated management of solid waste are presented in this study, specifically: non-recyclable plastics from source separation, mechanical-biological treated municipal solid waste and a special waste, automotive shredded residues. Results obtained demonstrate that washing treatment contributes towards combating the environmental impacts of raw wastes. Accordingly, a leachate production model was applied, leading to the consideration that the concentrations of chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN), parameters of fundamental importance in the characterization of landfill leachate, from a landfill containing washed wastes, are comparable to those that would only be reached between 90 and 220years later in the presence of raw wastes. The findings obtained demonstrated that washing of waste may represent an effective means of reducing the leachable fraction resulting in a consequent decrease in landfill emissions. Further studies on pilot scale are needed to assess the potential for full-scale application of this treatment. PMID:22245736

  11. Devices for the Production of Reference Gas Mixtures.

    PubMed

    Fijało, Cyprian; Dymerski, Tomasz; Gębicki, Jacek; Namieśnik, Jacek

    2016-09-01

    For many years there has been growing demand for gaseous reference materials, which is connected with development in many fields of science and technology. As a result, new methodological and instrumental solutions appear that can be used for this purpose. Appropriate quality assurance/quality control (QA/QC) must be used to make sure that measurement data are a reliable source of information. Reference materials are a significant element of such systems. In the case of gas samples, such materials are generally called reference gas mixtures. This article presents the application and classification of reference gas mixtures, which are a specific type of reference materials, and the methods for obtaining them are described. Construction solutions of devices for the production of reference gas mixtures are detailed, and a description of a prototype device for dynamic production of reference gas mixtures containing aroma compounds is presented. PMID:27437588

  12. Devices for the Production of Reference Gas Mixtures.

    PubMed

    Fijało, Cyprian; Dymerski, Tomasz; Gębicki, Jacek; Namieśnik, Jacek

    2016-09-01

    For many years there has been growing demand for gaseous reference materials, which is connected with development in many fields of science and technology. As a result, new methodological and instrumental solutions appear that can be used for this purpose. Appropriate quality assurance/quality control (QA/QC) must be used to make sure that measurement data are a reliable source of information. Reference materials are a significant element of such systems. In the case of gas samples, such materials are generally called reference gas mixtures. This article presents the application and classification of reference gas mixtures, which are a specific type of reference materials, and the methods for obtaining them are described. Construction solutions of devices for the production of reference gas mixtures are detailed, and a description of a prototype device for dynamic production of reference gas mixtures containing aroma compounds is presented.

  13. NOVEL REACTOR FOR THE PRODUCTION OF SYNTHESIS GAS

    SciTech Connect

    Vasilis Papavassiliou; Leo Bonnell; Dion Vlachos

    2004-12-01

    Praxair investigated an advanced technology for producing synthesis gas from natural gas and oxygen This production process combined the use of a short-reaction time catalyst with Praxair's gas mixing technology to provide a novel reactor system. The program achieved all of the milestones contained in the development plan for Phase I. We were able to develop a reactor configuration that was able to operate at high pressures (up to 19atm). This new reactor technology was used as the basis for a new process for the conversion of natural gas to liquid products (Gas to Liquids or GTL). Economic analysis indicated that the new process could provide a 8-10% cost advantage over conventional technology. The economic prediction although favorable was not encouraging enough for a high risk program like this. Praxair decided to terminate development.

  14. Evaluation of the gas production economics of the gas hydrate cyclic thermal injection model

    SciTech Connect

    Kuuskraa, V.A.; Hammersheimb, E.; Sawyer, W.

    1985-05-01

    The objective of the work performed under this directive is to assess whether gas hydrates could potentially be technically and economically recoverable. The technical potential and economics of recovering gas from a representative hydrate reservoir will be established using the cyclic thermal injection model, HYDMOD, appropriately modified for this effort, integrated with economics model for gas production on the North Slope of Alaska, and in the deep offshore Atlantic. The results from this effort are presented in this document. In Section 1, the engineering cost and financial analysis model used in performing the economic analysis of gas production from hydrates -- the Hydrates Gas Economics Model (HGEM) -- is described. Section 2 contains a users guide for HGEM. In Section 3, a preliminary economic assessment of the gas production economics of the gas hydrate cyclic thermal injection model is presented. Section 4 contains a summary critique of existing hydrate gas recovery models. Finally, Section 5 summarizes the model modification made to HYDMOD, the cyclic thermal injection model for hydrate gas recovery, in order to perform this analysis.

  15. Management of landfill leachate: The legacy of European Union Directives.

    PubMed

    Brennan, R B; Healy, M G; Morrison, L; Hynes, S; Norton, D; Clifford, E

    2016-09-01

    Landfill leachate is the product of water that has percolated through waste deposits and contains various pollutants, which necessitate effective treatment before it can be released into the environment. In the last 30years, there have been significant changes in landfill management practices in response to European Union (EU) Directives, which have led to changes in leachate composition, volumes produced and treatability. In this study, historic landfill data, combined with leachate characterisation data, were used to determine the impacts of EU Directives on landfill leachate management, composition and treatability. Inhibitory compounds including ammonium (NH4-N), cyanide, chromium, nickel and zinc, were present in young leachate at levels that may inhibit ammonium oxidising bacteria, while arsenic, copper and silver were present in young and intermediate age leachate at concentrations above inhibitory thresholds. In addition, the results of this study show that while young landfills produce less than 50% of total leachate by volume in the Republic of Ireland, they account for 70% of total annual leachate chemical oxygen demand (COD) load and approximately 80% of total 5-day biochemical oxygen demand (BOD5) and NH4-N loads. These results show that there has been a decrease in the volume of leachate produced per tonne of waste landfilled since enactment of the Landfill Directive, with a trend towards increased leachate strength (particularly COD and BOD5) during the initial five years of landfill operation. These changes may be attributed to changes in landfill management practices following the implementation of the Landfill Directive. However, this study did not demonstrate the impact of decreasing inputs of biodegradable municipal waste on leachate composition. Increasingly stringent wastewater treatment plant (WWTP) emission limit values represent a significant threat to the sustainability of co-treatment of leachate with municipal wastewater. In addition

  16. US production of natural gas from tight reservoirs

    SciTech Connect

    Not Available

    1993-10-18

    For the purposes of this report, tight gas reservoirs are defined as those that meet the Federal Energy Regulatory Commission`s (FERC) definition of tight. They are generally characterized by an average reservoir rock permeability to gas of 0.1 millidarcy or less and, absent artificial stimulation of production, by production rates that do not exceed 5 barrels of oil per day and certain specified daily volumes of gas which increase with the depth of the reservoir. All of the statistics presented in this report pertain to wells that have been classified, from 1978 through 1991, as tight according to the FERC; i.e., they are ``legally tight`` reservoirs. Additional production from ``geologically tight`` reservoirs that have not been classified tight according to the FERC rules has been excluded. This category includes all producing wells drilled into legally designated tight gas reservoirs prior to 1978 and all producing wells drilled into physically tight gas reservoirs that have not been designated legally tight. Therefore, all gas production referenced herein is eligible for the Section 29 tax credit. Although the qualification period for the credit expired at the end of 1992, wells that were spudded (began to be drilled) between 1978 and May 1988, and from November 5, 1990, through year end 1992, are eligible for the tax credit for a subsequent period of 10 years. This report updates the EIA`s tight gas production information through 1991 and considers further the history and effect on tight gas production of the Federal Government`s regulatory and tax policy actions. It also provides some high points of the geologic background needed to understand the nature and location of low-permeability reservoirs.

  17. Nitrous oxide flux from landfill leachate-sawdust nitrogenous compost.

    PubMed

    Hui, C H; So, M K; Lee, C M; Chan, G Y S

    2003-09-01

    Composted nitrogenous waste has the potential to produce excessive amounts of nitrous oxide (N2O), a potent greenhouse gas that also contributes to stratospheric ozone depletion. In this laboratory study, sawdust was irrigated with varying amounts of landfill leachate with high NH4+-N content (3950 mg l(-1)). Physicochemical properties, including the amount of N2O produced, were monitored during the composting process over 28 days. A rapid decline in NH4+-N in the first 4 days and increasing NO3--N for 11 days was followed by lower but stabilized levels of available-N, even with repeated leachate irrigation. Less than 0.03% of the leachate-applied N was lost as N2O. Higher leachate applications as much as tripled N2O production, but this represented a lesser proportion overall of the total nitrogen. Addition of glucose to the composting process had no significant effect on N2O production. The derived sawdust-leachate compost supported healthy growth of Sesbania rostrata. It is concluded that compost can be produced from sawdust irrigated with landfill leachate without substantial emission of N2O, although excessive flux of N2O remains about high application rates over longer time periods. PMID:12867187

  18. Effects of gas composition in headspace and bicarbonate concentrations in media on gas and methane production, degradability, and rumen fermentation using in vitro gas production techniques.

    PubMed

    Patra, Amlan Kumar; Yu, Zhongtang

    2013-07-01

    Headspace gas composition and bicarbonate concentrations in media can affect methane production and other characteristics of rumen fermentation in in vitro gas production systems, but these 2 important factors have not been evaluated systematically. In this study, these 2 factors were investigated with respect to gas and methane production, in vitro digestibility of feed substrate, and volatile fatty acid (VFA) profile using in vitro gas production techniques. Three headspace gas compositions (N2+ CO2+ H2 in the ratio of 90:5:5, CO2, and N2) with 2 substrate types (alfalfa hay only, and alfalfa hay and a concentrate mixture in a 50:50 ratio) in a 3×2 factorial design (experiment 1) and 3 headspace compositions (N2, N2 + CO2 in a 50:50 ratio, and CO2) with 3 bicarbonate concentrations (80, 100, and 120 mM) in a 3×3 factorial design (experiment 2) were evaluated. In experiment 1, total gas production (TGP) and net gas production (NGP) was the lowest for CO2, followed by N2, and then the gas mixture. Methane concentration in headspace gas after fermentation was greater for CO2 than for N2 and the gas mixture, whereas total methane production (TMP) and net methane production (NMP) were the greatest for CO2, followed by the gas mixture, and then N2. Headspace composition did not affect in vitro digestibility or the VFA profile, except molar percentages of propionate, which were greater for CO2 and N2 than for the gas mixture. Methane concentration in headspace gas, TGP, and NGP were affected by the interaction of headspace gas composition and substrate type. In experiment 2, increasing concentrations of CO2 in the headspace decreased TGP and NGP quadratically, but increased the concentrations of methane, NMP, and in vitro fiber digestibility linearly, and TMP quadratically. Fiber digestibility, TGP, and NGP increased linearly with increasing bicarbonate concentrations in the medium. Concentrations of methane and NMP were unaffected by bicarbonate concentration, but

  19. Production of Substitute Natural Gas from Coal

    SciTech Connect

    Andrew Lucero

    2009-01-31

    The goal of this research program was to develop and demonstrate a novel gasification technology to produce substitute natural gas (SNG) from coal. The technology relies on a continuous sequential processing method that differs substantially from the historic methanation or hydro-gasification processing technologies. The thermo-chemistry relies on all the same reactions, but the processing sequences are different. The proposed concept is appropriate for western sub-bituminous coals, which tend to be composed of about half fixed carbon and about half volatile matter (dry ash-free basis). In the most general terms the process requires four steps (1) separating the fixed carbon from the volatile matter (pyrolysis); (2) converting the volatile fraction into syngas (reforming); (3) reacting the syngas with heated carbon to make methane-rich fuel gas (methanation and hydro-gasification); and (4) generating process heat by combusting residual char (combustion). A key feature of this technology is that no oxygen plant is needed for char combustion.

  20. The biological impact of landfill leachate on nearby surface water

    SciTech Connect

    Geis, S.W.

    1994-12-31

    Five landfill sites were evaluated for their potential to adversely impact the biotic community of surface waters. Acute and chronic aquatic toxicity tests were used to determine the toxicity of water samples collected from landfill monitoring wells and the nearest surface water. Four of the five landfill sites exhibited acute or chronic toxicity to Ceriodaphnia dubia, Daphnia magna, or Pimephales promelas. Toxicity identification procedures performed on water samples revealed toxic responses to metals and one toxic response to organic compounds. Surface water toxicity at an industrial landfill is most likely due to zinc from a tire production facility. Iron and a surfactant were determined to be the probable causes for toxicity at two municipal solid waste landfills.

  1. Gas and particulate phase products from the ozonolysis of acenaphthylene

    NASA Astrophysics Data System (ADS)

    Riva, Matthieu; Healy, Robert M.; Tomaz, Sophie; Flaud, Pierre-Marie; Perraudin, Emilie; Wenger, John C.; Villenave, Eric

    2016-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are recognized as important secondary organic aerosol (SOA) precursors in the urban atmosphere. In this work, the gas-phase ozonolysis of acenaphthylene was investigated in an atmospheric simulation chamber using a proton transfer reaction time-of-flight-mass spectrometer (PTR-TOF-MS) and an aerosol time-of-flight-mass spectrometer (ATOFMS) for on-line characterization of the oxidation products in the gas and particle phases, respectively. SOA samples were also collected on filters and analyzed by ultra performance liquid chromatography/electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-QTOFMS) and gas chromatography/electron impact ionization-mass spectrometry (GC/EI-MS). The major gas-phase products included a range of oxygenated naphthalene derivatives such as 1,8-naphthalic anhydride, naphthalene 1,8-dicarbaldehyde and naphthaldehyde, as well as a secondary ozonide. Possible reaction mechanisms are proposed for the formation of these products and favoured pathways have been suggested. Many of these products were also found in the particle phase along with a range of oligomeric compounds. The same range of gas and particle phase products was observed in the presence and absence of excess cyclohexane, an OH scavenger, indicating that OH radical production from the ozonolysis of acenaphthylene is negligible. SOA yields in the range 23-37% were determined and indicate that acenaphthylene ozonolysis may contribute to part of the SOA observed in urban areas.

  2. Water Resources and Natural Gas Production from the Marcellus Shale

    USGS Publications Warehouse

    Soeder, Daniel J.; Kappel, William M.

    2009-01-01

    The Marcellus Shale is a sedimentary rock formation deposited over 350 million years ago in a shallow inland sea located in the eastern United States where the present-day Appalachian Mountains now stand (de Witt and others, 1993). This shale contains significant quantities of natural gas. New developments in drilling technology, along with higher wellhead prices, have made the Marcellus Shale an important natural gas resource. The Marcellus Shale extends from southern New York across Pennsylvania, and into western Maryland, West Virginia, and eastern Ohio (fig. 1). The production of commercial quantities of gas from this shale requires large volumes of water to drill and hydraulically fracture the rock. This water must be recovered from the well and disposed of before the gas can flow. Concerns about the availability of water supplies needed for gas production, and questions about wastewater disposal have been raised by water-resource agencies and citizens throughout the Marcellus Shale gas development region. This Fact Sheet explains the basics of Marcellus Shale gas production, with the intent of helping the reader better understand the framework of the water-resource questions and concerns.

  3. Talking trash: the economic and environmental issues of landfills.

    PubMed

    Taylor, D

    1999-08-01

    The U.S. per-capita figure for garbage production has topped four pounds per person per day, and that amount is rising at roughly 5% per year. In the past, municipal solid waste was sent to the nearest local landfill or incinerator. But in 1988, the U.S. Environmental Protection Agency instituted the first federal standards for landfills, designed to make them safer. Over 10,000 small municipal landfills have since been consolidated into an estimated 3,500 newer, safer landfills, some of which are "megafills" that can handle up to 10,000 tons of waste a day. The new landfills are outfitted to prevent air and water pollution and limit the spread of disease by scavengers. Although the new landfills provide better controls against air and water pollution as well as an alternate source of municipal income, they are not entirely problem-free. Some experts believe the new landfill technology has not been properly tested and will therefore not provide protection in the long run. Others feel that poorer, less well-informed communities are targeted as sites for new landfills. In addition, many people that live near megafills, which may draw garbarge from several states, are unhappy about the noise, truck traffic, odors, and pests caused by the facilities.

  4. Talking trash: the economic and environmental issues of landfills.

    PubMed Central

    Taylor, D

    1999-01-01

    The U.S. per-capita figure for garbage production has topped four pounds per person per day, and that amount is rising at roughly 5% per year. In the past, municipal solid waste was sent to the nearest local landfill or incinerator. But in 1988, the U.S. Environmental Protection Agency instituted the first federal standards for landfills, designed to make them safer. Over 10,000 small municipal landfills have since been consolidated into an estimated 3,500 newer, safer landfills, some of which are "megafills" that can handle up to 10,000 tons of waste a day. The new landfills are outfitted to prevent air and water pollution and limit the spread of disease by scavengers. Although the new landfills provide better controls against air and water pollution as well as an alternate source of municipal income, they are not entirely problem-free. Some experts believe the new landfill technology has not been properly tested and will therefore not provide protection in the long run. Others feel that poorer, less well-informed communities are targeted as sites for new landfills. In addition, many people that live near megafills, which may draw garbarge from several states, are unhappy about the noise, truck traffic, odors, and pests caused by the facilities. PMID:10417373

  5. Environmental Isotope Characteristics of Landfill Leachates and Gases

    USGS Publications Warehouse

    Hackley, Keith C.; Liu, Chao-Li; Coleman, D.D.

    1996-01-01

    The isotopic characteristics of municipal landfill leachate and gases (carbon dioxide and methane) are unique relative to the aqueous and gaseous media in most other natural geologic environments. The ??13 C of the CO2 in landfills is significantly enriched in 13C, with values as high as +20??? reported. The ?? 13C and ??D values of the methane fall within a range of values representative of microbial methane produced primarily by the acetate-fermentation process. The ??D of landfill leachate is strongly enriched in deuterium, by approximately 30??? to nearly 60??? relative to local average precipitation values. This deuterium enrichment is undoubtedly due to the extensive production of microbial methane within the limited reservoir of a landfill. The concentration of the radiogenic isotopes, 14C and 3H, are significantly elevated in both landfill leachate and methane. The 14C values range between approximately 120 and 170 pMC and can be explained by the input of organic material that was affected by the increased 14C content of atmospheric CO2 caused by atmospheric testing of nuclear devices. The tritium measured in leachate, however, is often too high to be explained by previous atmospheric levels and must come from material buried within the landfill. The unique isotopic characteristics observed in landfill leachates and gases provide a very useful technique for confirming whether contamination is from a municipal landfill or some other local source.

  6. Optimizing landfill site selection by using land classification maps.

    PubMed

    Eskandari, M; Homaee, M; Mahmoodi, S; Pazira, E; Van Genuchten, M Th

    2015-05-01

    Municipal solid waste disposal is a major environmental concern throughout the world. Proper landfill siting involves many environmental, economic, technical, and sociocultural challenges. In this study, a new quantitative method for landfill siting that reduces the number of evaluation criteria, simplifies siting procedures, and enhances the utility of available land evaluation maps was proposed. The method is demonstrated by selecting a suitable landfill site near the city of Marvdasht in Iran. The approach involves two separate stages. First, necessary criteria for preliminary landfill siting using four constraints and eight factors were obtained from a land classification map initially prepared for irrigation purposes. Thereafter, the criteria were standardized using a rating approach and then weighted to obtain a suitability map for landfill siting, with ratings in a 0-1 domain and divided into five suitability classes. Results were almost identical to those obtained with a more traditional environmental landfill siting approach. Because of far fewer evaluation criteria, the proposed weighting method was much easier to implement while producing a more convincing database for landfill siting. The classification map also considered land productivity. In the second stage, the six best alternative sites were evaluated for final landfill siting using four additional criteria. Sensitivity analyses were furthermore conducted to assess the stability of the obtained ranking. Results indicate that the method provides a precise siting procedure that should convince all pertinent stakeholders.

  7. Role of iron in H(2)S emission behavior during the decomposition of biodegradable substrates in landfill.

    PubMed

    Du, Yao; Feng, Huan; Zhang, Kun; Hu, Li-Fang; Fang, Cheng-Ran; Shen, Dong-Sheng; Long, Yu-Yang

    2014-05-15

    Hydrogen sulfide (H2S) is regarded as a major odor causing compound in landfill gas that may lead to adverse environmental and health effects. In this study, the potential role of iron in the entire life cycle of H2S production and emission was investigated during the decomposition of biodegradable substrates in the landfilled refuse. The results showed that the quantity of H2S emission decreased about 95% when Fe(OH)3 was present in the biodegradable sulfur-containing substrates. During this degradation process, a lot of sulfide was generated, which was present mostly as ferrous sulfide. In addition, a total of 7.68% S-H2S of total sulfur released as gas phase could be remained in solid-liquid phase effectively in the simulated substrates with iron. Thus, using the appropriate way to take advantage of iron "hidden" in the landfilled refuse might be a good choice for in situ control of H2S emission. Moreover, if this high level of iron is not presented, landfill odor pollution might become more serious. PMID:24675612

  8. On-Board Hydrogen Gas Production System For Stirling Engines

    DOEpatents

    Johansson, Lennart N.

    2004-06-29

    A hydrogen production system for use in connection with Stirling engines. The production system generates hydrogen working gas and periodically supplies it to the Stirling engine as its working fluid in instances where loss of such working fluid occurs through usage through operation of the associated Stirling engine. The hydrogen gas may be generated by various techniques including electrolysis and stored by various means including the use of a metal hydride absorbing material. By controlling the temperature of the absorbing material, the stored hydrogen gas may be provided to the Stirling engine as needed. A hydrogen production system for use in connection with Stirling engines. The production system generates hydrogen working gas and periodically supplies it to the Stirling engine as its working fluid in instances where loss of such working fluid occurs through usage through operation of the associated Stirling engine. The hydrogen gas may be generated by various techniques including electrolysis and stored by various means including the use of a metal hydride absorbing material. By controlling the temperature of the absorbing material, the stored hydrogen gas may be provided to the Stirling engine as needed.

  9. Gas Production from Hydrate-Bearing Sediments - Emergent Phenomena -

    SciTech Connect

    Jung, J.W.; Jang, J.W.; Tsouris, Costas; Phelps, Tommy Joe; Rawn, Claudia J; Santamarina, Carlos

    2012-01-01

    Even a small fraction of fine particles can have a significant effect on gas production from hydrate-bearing sediments and sediment stability. Experiments were conducted to investigate the role of fine particles on gas production using a soil chamber that allows for the application of an effective stress to the sediment. This chamber was instrumented to monitor shear-wave velocity, temperature, pressure, and volume change during CO{sub 2} hydrate formation and gas production. The instrumented chamber was placed inside the Oak Ridge National Laboratory Seafloor Process Simulator (SPS), which was used to control the fluid pressure and temperature. Experiments were conducted with different sediment types and pressure-temperature histories. Fines migrated within the sediment in the direction of fluid flow. A vuggy structure formed in the sand; these small cavities or vuggs were precursors to the development of gas-driven fractures during depressurization under a constant effective stress boundary condition. We define the critical fines fraction as the clay-to-sand mass ratio when clays fill the pore space in the sand. Fines migration, clogging, vugs, and gas-driven fracture formation developed even when the fines content was significantly lower than the critical fines fraction. These results show the importance of fines in gas production from hydrate-bearing sediments, even when the fines content is relatively low.

  10. Mesoscale Laboratory Models of the Biodegradation of Municipal Landfill Materials

    NASA Astrophysics Data System (ADS)

    Borglin, S. E.; Hazen, T. C.; Oldenburg, C. M.; Zawislanski, P. T.

    2001-12-01

    Stabilization of municipal landfills is a critical issue involving land reuse, leachate treatment, and odor control. In an effort to increase landfill stabilization rates and decrease leachate treatment costs, municipal landfills can be operated as active aerobic or anaerobic bioreactors. Rates of settling and biodegradation were compared in three different treatments of municipal landfill materials in laboratory-scale bioreactors. Each of the three fifty-five-gallon clear acrylic tanks was fitted with pressure transducers, thermistors, neutron probe access tubes, a leachate recirculation system, gas vents, and air injection ports. The treatments applied to the tanks were (a) aerobic (air injection with leachate recirculation and venting from the top), (b) anaerobic (leachate recirculation with passive venting from the top), and (c) a control tank (passive venting from the top and no leachate recirculation). All tanks contained a 10-cm-thick layer of pea gravel at the bottom, overlain by a mixture of fresh waste materials on the order of 5-10 cm in size to an initial height of 0.55 m. Concentrations of O2, CO2 and CH4 were measured at the gas vent, and leachate was collected at the bottom drain. The water saturation in the aerobic and anaerobic tanks averaged 17 % and the control tank averaged 1 %. Relative degradation rates between the tanks were monitored by CO2 and CH4 production rates and O2 respiration rates. Respiration tests on the aerobic tank show a decrease in oxygen consumption rates from 1.3 mol/day at 20 days to 0.1 mol/day at 300 days, indicating usable organics are being depleted. The anaerobic tank produced measurable methane after 300 days that increased to 41% by volume after 370 days. Over the test period, the aerobic tank settled 30 %, the anaerobic tank 18.5 %, and the control tank 11.1 %. The concentrations of metals, nitrate, phosphate, and total organic carbon in the aerobic tank leachate are an order of magnitude lower than in the anaerobic

  11. Generating CO{sub 2}-credits through landfill in situ aeration

    SciTech Connect

    Ritzkowski, M.; Stegmann, R.

    2010-04-15

    Landfills are some of the major anthropogenic sources of methane emissions worldwide. The installation and operation of gas extraction systems for many landfills in Europe and the US, often including technical installations for energy recovery, significantly reduced these emissions during the last decades. Residual landfill gas, however, is still continuously produced after the energy recovery became economically unattractive, thus resulting in ongoing methane emissions for many years. By landfill in situ aeration these methane emissions can be widely avoided both, during the aeration process as well as in the subsequent aftercare period. Based on model calculations and online monitoring data the amount of avoided CO{sub 2-eq}. can be determined. For an in situ aerated landfill in northern Germany, acting as a case study, 83-95% (depending on the kind and quality of top cover) of the greenhouse gas emission potential could be reduced under strictly controlled conditions. Recently the United Nations Framework Convention on Climate Change (UNFCCC) has approved a new methodology on the 'Avoidance of landfill gas emissions by in situ aeration of landfills' (). Based on this methodology landfill aeration projects might be considered for generation of Certified Emission Reductions (CERs) in the course of CDM projects. This paper contributes towards an evaluation of the potential of landfill aeration for methane emissions reduction.

  12. Valorization of Flue Gas by Combining Photocatalytic Gas Pretreatment with Microalgae Production.

    PubMed

    Eynde, Erik Van; Lenaerts, Britt; Tytgat, Tom; Blust, Ronny; Lenaerts, Silvia

    2016-03-01

    Utilization of flue gas for algae cultivation seems to be a promising route because flue gas from fossil-fuel combustion processes contains the high amounts of carbon (CO2) and nitrogen (NO) that are required for algae growth. NO is a poor nitrogen source for algae cultivation because of its low reactivity and solublilty in water and its toxicity for algae at high concentrations. Here, we present a novel strategy to valorize NO from flue gas as feedstock for algae production by combining a photocatalytic gas pretreatment unit with a microalgal photobioreactor. The photocatalytic air pretreatment transforms NO gas into NO2 gas and thereby enhances the absorption of NOx in the cultivation broth. The absorbed NOx will form NO2(-) and NO3(-) that can be used as a nitrogen source by algae. The effect of photocatalytic air pretreatment on the growth and biomass productivity of the algae Thalassiosira weissflogii in a semicontinuous system aerated with a model flue gas (1% CO2 and 50 ppm of NO) is investigated during a long-term experiment. The integrated system makes it possible to produce algae with NO from flue gas as the sole nitrogen source and reduces the NOx content in the exhaust gas by 84%.

  13. Valorization of Flue Gas by Combining Photocatalytic Gas Pretreatment with Microalgae Production.

    PubMed

    Eynde, Erik Van; Lenaerts, Britt; Tytgat, Tom; Blust, Ronny; Lenaerts, Silvia

    2016-03-01

    Utilization of flue gas for algae cultivation seems to be a promising route because flue gas from fossil-fuel combustion processes contains the high amounts of carbon (CO2) and nitrogen (NO) that are required for algae growth. NO is a poor nitrogen source for algae cultivation because of its low reactivity and solublilty in water and its toxicity for algae at high concentrations. Here, we present a novel strategy to valorize NO from flue gas as feedstock for algae production by combining a photocatalytic gas pretreatment unit with a microalgal photobioreactor. The photocatalytic air pretreatment transforms NO gas into NO2 gas and thereby enhances the absorption of NOx in the cultivation broth. The absorbed NOx will form NO2(-) and NO3(-) that can be used as a nitrogen source by algae. The effect of photocatalytic air pretreatment on the growth and biomass productivity of the algae Thalassiosira weissflogii in a semicontinuous system aerated with a model flue gas (1% CO2 and 50 ppm of NO) is investigated during a long-term experiment. The integrated system makes it possible to produce algae with NO from flue gas as the sole nitrogen source and reduces the NOx content in the exhaust gas by 84%. PMID:26838336

  14. Attenuation of Landfill Leachate In Unsaturated Sandstone

    NASA Astrophysics Data System (ADS)

    Butler, A. P.; Brook, C.; Godley, A.; Lewin, K.; Young, C. P.

    feature of the sequences of porewater concentration profiles is the sharp leading front of the Cl plume. Thus indicating that very little solute dispersion appears to be occurring. This is probably to be due to the relatively uniform particle size of the sand matrix combined with the low moisture content, which has greatly constrained the available pore sizes in which flow occurs. A marked reduction in the mass of the chloride plume has been observed over the last 13 years. Analyses of core sample taken in 2000 show that the Cl profile has continued to lose mass and has now also separated into two peaks. The leading peak was located at a depth of 36 m below ground level (28 m below the base of the landfill) and in line with model predictions. The trailing peak was at a depth of 27 m bgl and was associated with a 0.3 m layer of marl and clay bands. Thus there is an indication that the changes in chloride mass are possibly due to the effects of heterogeneity, although other processes which could account for chloride removal from solution are also under consideration. The location of the TOC front up to 1992 was commensurate with that of Cl, indicating no effective retardation. This is consistent with the very low levels of organic carbon present in the sandstone. However, marked reductions in contaminant mass (substantially greater than those of Cl) have been observed. Analyses of volatile fatty acids has indicated a progressive breakdown of VFA components leading to simpler products so that by 1991 the dominant component was ethanoic acid (56% by mass). By 2000 the entire leading front of the TOC was absent. TOC was only found to be present at relatively low concentrations ( 100 mg.l-1) above the marl/clay band. Analyses of gas concentrations at the site have indicated that there has been a change in the redox potential in the volume of contaminated unsaturated sandstone below the waste cells during the last 10 years. With predominantly anaerobic conditions giving way to

  15. Pumps, refracturing hike production from tight shale gas wells

    SciTech Connect

    Reeves, S.R. ); Morrisson, W.K. ); Hill, D.G. )

    1993-02-01

    This paper reports that downhole pumps and refracturing are two ways to significantly improve production rates from the Antrim shale, a tight formation in the Michigan basin (U.S.) and the objective of a major natural gas play. Candidate wells for restimulation can be identified by pressure build-up tests and specifically productivity index-vs.-permeability plots based on these tests. The work in the Bagley East B4-10 well illustrates the possible production improvement.

  16. Group-specific quantification of methanotrophs in landfill gas-purged laboratory biofilters by tyramide signal amplification-fluorescence in situ hybridization.

    PubMed

    Wang, Hong; Einola, Juha; Heinonen, Mirja; Kulomaa, Markku; Rintala, Jukka

    2008-09-01

    The aim of this study was to quantitatively analyse methanotrophs in two laboratory landfill biofilters at different biofilter depths and at temperatures which mimicked the boreal climatic conditions. Both biofilters were dominated by type I methanotrophs. The biofilter depth profiles showed that type I methanotrophs occurred in the upper layer, where relatively high O(2) and low CH(4) concentrations were present, whereas type II methanotrophs were mostly distributed in the zone with high CH(4) and low O(2) concentrations. The number of type I methanotrophic cells declined when the temperature was raised from 15 degrees C to 23 degrees C, but increased when lowered to 5 degrees C. A slight decrease in type II methanotrophs was also observed when the temperature was raised from 15 degrees C to 23 degrees C, whereas cell numbers remained constant when lowered to 5 degrees C. The results indicated that low temperature conditions favored both type I and type II methanotrophs in the biofilters.

  17. Post-closure care of engineered municipal solid waste landfills.

    PubMed

    Bagchi, Amalendu; Bhattacharya, Abhik

    2015-03-01

    Post-closure care is divided into perpetual care (PPC) and long-term care (LTC). Guidelines for post-closure care and associated costs are important for engineered municipal solid waste (MSW) landfills. In many states in the USA, landfill owners are required to set aside funds for 30-40 years of LTC. Currently there are no guidelines for PPC, which is also required. We undertook a pilot study, using two landfills (note: average landfill capacity 2.5 million MT MSW waste) in Wisconsin, to establish an approach for estimating the LTC period using field data and PPC funding need. Statistical analysis of time versus concentration data of selected leachate parameters showed that the concentration of most parameters is expected to be at or below the preventive action limit of groundwater and leachate volume will be very low, within 40 years of the LTC period. The gas extraction system may need to be continued for more than 100 years. Due to lack of data no conclusion could be made regarding adequacy of the LTC period for the groundwater monitoring system. The final cover must be maintained for perpetuity. The pilot study shows that although technology is available, the financial liability of maintaining a 'Dry Tomb' design for landfills is significantly higher than commonly perceived. The paper will help landfill professionals to estimate realistic post-closure funding and to develop field-based policies for LTC and PPC of engineered MSW landfills. PMID:25687915

  18. Engineering analysis of biomass gasifier product gas cleaning technology

    SciTech Connect

    Baker, E.G.; Brown, M.D.; Moore, R.H.; Mudge, L.K.; Elliott, D.C.

    1986-08-01

    For biomass gasification to make a significant contribution to the energy picture in the next decade, emphasis must be placed on the generation of clean, pollutant-free gas products. This reports attempts to quantify levels of particulated, tars, oils, and various other pollutants generated by biomass gasifiers of all types. End uses for biomass gases and appropriate gas cleaning technologies are examined. Complete systems analysis is used to predit the performance of various gasifier/gas cleanup/end use combinations. Further research needs are identified. 128 refs., 20 figs., 19 tabs.

  19. Depressurization and electrical heating of hydrate sediment for gas production

    NASA Astrophysics Data System (ADS)

    Minagawa, H.; Ito, T.; Kimura, S.; Kaneko, H.; Noda, S.; Narita, H.

    2014-12-01

    In-situ dissociation of natural gas hydrate is necessary for commercial recovery of natural gas from natural gas hydrate sediment. Thermal stimulation is an effective dissociation method, along with depressurization. In this study, we examined the efficiency of electrical heating of the hydrate core for gas production. In order to evaluate efficiency of electrical heating with depressurization, we investigated following subject. (1) electrical heating of Xe gas hydrate sediment, as a conventional simulation of methane hydrate sediment, (2) electrical heating of methane hydrate sediment, which was compared with Xe gas hydrate experiment, and (3) electrical heating of hydrate bearing sediment with fine sandy layer which was simulated faults with large displacement shear around hydrate sediment. These experiments revealed that depressurization and additional electrode heating of hydrate sediment saturated with electrolyte solution was confirmed to enable higher efficient and effective gas production from sedimentwith less electric power. This study is financially supported by METI and Research Consortium for Methane Hydrate Resources in Japan (the MH21 Research Consortium).

  20. Synthesis gas production by mixed conducting membranes with integrated conversion into liquid products

    DOEpatents

    Nataraj, Shankar; Russek, Steven Lee; Dyer, Paul Nigel

    2000-01-01

    Natural gas or other methane-containing feed gas is converted to a C.sub.5 -C.sub.19 hydrocarbon liquid in an integrated system comprising an oxygenative synthesis gas generator, a non-oxygenative synthesis gas generator, and a hydrocarbon synthesis process such as the Fischer-Tropsch process. The oxygenative synthesis gas generator is a mixed conducting membrane reactor system and the non-oxygenative synthesis gas generator is preferably a heat exchange reformer wherein heat is provided by hot synthesis gas product from the mixed conducting membrane reactor system. Offgas and water from the Fischer-Tropsch process can be recycled to the synthesis gas generation system individually or in combination.

  1. Cascade heat recovery with coproduct gas production

    DOEpatents

    Brown, William R.; Cassano, Anthony A.; Dunbobbin, Brian R.; Rao, Pradip; Erickson, Donald C.

    1986-01-01

    A process for the integration of a chemical absorption separation of oxygen and nitrogen from air with a combustion process is set forth wherein excess temperature availability from the combustion process is more effectively utilized to desorb oxygen product from the absorbent and then the sensible heat and absorption reaction heat is further utilized to produce a high temperature process stream. The oxygen may be utilized to enrich the combustion process wherein the high temperature heat for desorption is conducted in a heat exchange preferably performed with a pressure differential of less than 10 atmospheres which provides considerable flexibility in the heat exchange.

  2. Cascade heat recovery with coproduct gas production

    DOEpatents

    Brown, W.R.; Cassano, A.A.; Dunbobbin, B.R.; Rao, P.; Erickson, D.C.

    1986-10-14

    A process for the integration of a chemical absorption separation of oxygen and nitrogen from air with a combustion process is set forth wherein excess temperature availability from the combustion process is more effectively utilized to desorb oxygen product from the absorbent and then the sensible heat and absorption reaction heat is further utilized to produce a high temperature process stream. The oxygen may be utilized to enrich the combustion process wherein the high temperature heat for desorption is conducted in a heat exchange preferably performed with a pressure differential of less than 10 atmospheres which provides considerable flexibility in the heat exchange. 4 figs.

  3. Natural gas production from hydrate dissociation: An axisymmetric model

    SciTech Connect

    Ahmadi, G.; Ji, Chuang; Smith, D.H.

    2007-08-01

    This paper describes an axisymmetric model for natural gas production from the dissociation of methane hydrate in a confined reservoir by a depressurizing well. During the hydrate dissociation, heat and mass transfer in the reservoir are analyzed. The system of governing equations is solved by a finite difference scheme. For different well pressures and reservoir temperatures, distributions of temperature and pressure in the reservoir, as well as the natural gas production from the well are evaluated. The numerical results are compared with those obtained by a linearization method. It is shown that the gas production rate is a sensitive function of well pressure. The simulation results are compared with the linearization approach and the shortcomings of the earlier approach are discussed.

  4. Attenuation of landfill leachate at two uncontrolled landfills

    NASA Astrophysics Data System (ADS)

    Lee, Jin-Yong; Cheon, Jeong-Yong; Kwon, Hyung-Pyo; Yoon, Hee-Sung; Lee, Seong-Sun; Kim, Jong-Ho; Park, Joung-Ku; Kim, Chang-Gyun

    2006-12-01

    Attenuation characteristics of landfill leachate were examined for two uncontrolled landfills in Korea. The two landfills containing municipal wastes without appropriate bottom liner and leachate treatment system have different landfill age, waste volume, and most importantly different hydrogeologic settings. One landfill (Cheonan landfill) is situated in an open flat area while the other (Wonju landfill) is located in a valley. Variations of various parameters including dissolved organic carbon (DOC), dissolved oxygen (DO), alkalinity, pH, electrical conductivity (EC), redox potential (ORP), ammonia (NH3), nitrate (NO{3/-}), sulfate (SO{4/2-}), and chloride (Cl-) were examined along groundwater flow path. All these parameters were analyzed every month for a year. In the interior of the landfills, typical anaerobic conditions revealed by low DO and NO3 concentrations, negative ORP values, high NH3, alkalinity, and Cl- concentrations were observed. Generally, higher levels of contaminants (DOC, NH3, and Cl-) were detected in the dry season while they were greatly lowered in the wet season. Significantly, large decrease of Cl- concentration in the wet season indicates that the dilution or mixing is one of dominant attenuation mechanisms of leachate. But detailed variation behaviors in the two landfills are different and they were largely dependent on permeability of surface and subsurface layers. The intermediately permeable surface of the landfills receives part of direct rainfall infiltration but most rainwater is lost to fast runoff. The practically impermeable surface of clayey silt (paddy field) at immediately adjacent to the Cheonan landfill boundary prevented direct rainwater infiltration and hence redox condition of the ground waters were largely affected by that of the upper landfill and the less permeable materials beneath the paddy fields prohibited dispersion of the landfill leachate into down gradient area. In the Wonju landfill, there are three

  5. Multiphase Modeling of Flow, Transport, and Biodegradation in a Mesoscale Landfill Bioreactor

    SciTech Connect

    Oldenburg, Curtis M.; Borglin, Sharon E.; Hazen, Terry C.

    2002-02-01

    The need to control gas and leachate production and minimize refuse volume in municipal solid waste landfills has motivated the development of landfill simulation models to predict and design optimal treatment processes. We have developed a multiphase and multicomponent nonisothermal module called T2LBM for the three-dimensional TOUGH2 flow and transport simulator. T2LBM can be used to simulate aerobic or anaerobic biodegradation of municipal solid waste and the associated flow and transport of gas and liquid through the refuse mass. Acetic acid is used as a proxy for all biodegradable substrates in the refuse. T2LBM incorporates a Monod kinetic rate law for the biodegradation of acetic acid by either aerobic or anaerobic microbes as controlled by the local oxygen concentration. We have verified the model against published data, and applied it to our own mesoscale laboratory aerobic landfill bioreactor experiments. We observe spatial variability of flow and biodegradation consistent with permeability heterogeneity and the geometry of the radial grid. The model is capable of matching results of a shut-in test where the respiration of the system is measured over time.

  6. Kinetics study on biomass pyrolysis for fuel gas production.

    PubMed

    Chen, Guan-Yi; Fang, Meng-Xiang; Andries, J; Luo, Zhong-Yang; Spliethoff, H; Cen, Ke-Fa

    2003-01-01

    Kinetic knowledge is of great importance in achieving good control of the pyrolysis and gasification process and optimising system design. An overall kinetic pyrolysis scheme is therefore addressed here. The kinetic modelling incorporates the following basic steps: the degradation of the virgin biomass materials into primary products (tar, gas and semi-char), the decomposition of primary tar into secondary products and the continuous interaction between primary gas and char. The last step is disregarded completely by models in the literature. Analysis and comparison of predicted results from different kinetic schemes and experimental data on our fixed bed pyrolyser yielded very positive evidence to support our kinetic scheme. PMID:12861621

  7. Gas production from oceanic Class 2 hydrate accumulations

    SciTech Connect

    Moridis, G.J.; Reagan, M.T.

    2007-02-01

    Gas hydrates are solid crystalline compounds in which gasmolecules are lodged within the lattices of ice crystals. The vastamounts of hydrocarbon gases that are trapped in hydrate deposits in thepermafrost and in deep ocean sediments may constitute a promising energysource. Class 2 hydrate deposits are characterized by a Hydrate-BearingLayer (HBL) that is underlain by a saturated zone of mobile water. Inthis study we investigated three methods of gas production via verticalwell designs. A long perforated interval (covering the hydrate layer andextending into the underlying water zone) yields the highest gasproduction rates (up to 20 MMSCFD), but is not recommended for long-termproduction because of severe flow blockage caused by secondary hydrateand ice. A short perforated interval entirely within the water zoneallows long-term production, but only at rates of 4.5 7 MMSCFD. A newwell design involving localized heating appears to be the most promising,alleviating possible blockage by secondary hydrate and/or ice near thewellbore) and delivering sustainably large, long-term rates (10-15MMSCFD).The production strategy involves a cyclical process. During eachcycle, gas production continuously increases, while the correspondingwater production continuously decreases. Each cycle is concluded by acavitation event (marked by a precipitous pressure drop at the well),brought about by the inability of thesystem to satisfy the constant massproduction rate QM imposed at the well. This is caused by the increasinggas contribution to the production stream, and/or flow inhibition causedby secondary hydrate and/or ice. In the latter case, short-term thermalstimulation removes the blockage. The results show that gas productionincreases (and the corresponding water-to-gas ratio RWGC decreases) withan increasing(a) QM, (b) hydrate temperature (which defines its stabilityfor a given pressure), and (c) intrinsic permeability. Lower initialhydrate saturations lead initially to higher gas

  8. Hazardous Gas Production by Alpha Particles

    SciTech Connect

    Jay A. LaVerne, Principal Investigator

    2001-11-26

    This project focused on the production of hazardous gases in the radiolysis of solid organic matrices, such as polymers and resins, that may be associated with transuranic waste material. Self-radiolysis of radioactive waste is a serious environmental problem because it can lead to a change in the composition of the materials in storage containers and possibly jeopardize their integrity. Experimental determination of gaseous yields is of immediate practical importance in the engineering and maintenance of containers for waste materials. Fundamental knowledge on the radiation chemical processes occurring in these systems allows one to predict outcomes in materials or mixtures not specifically examined, which is a great aid in the management of the variety of waste materials currently overseen by Environmental Management.

  9. Natural gas supply product and services guide. 1996-1997 edition

    SciTech Connect

    1996-12-31

    This is the Gas Research Institute`s Natural Gas Supply Product and Services Guide for 1996-97. It presents gas exploration, production and processing products developed for Gas Research Institute (GRI) by its contractors, to help reduce production costs and increase recoverable reserves.

  10. U. S. EPA's global climate change program: Landfill emissions and mitigation research. Rept. for Aug 90-May 91

    SciTech Connect

    Thorneloe, S.A.

    1991-10-14

    The paper discusses the U.S. EPA's global climate change program, concentrating on global landfill methane (CH4) emissions and mitigation research. The EPA's Air and Energy Engineering Research Laboratory (AEERL) has begun research on developing more reliable emission estimates of the key greenhouse gas sources that are amenable to cost-effective control. Research has been initiated on biomass and CH4 utilization, tropospheric ozone, and evaluation of potential mitigation opportunities for emissions contributing to global climate change. The emissions program has begun to identify and quantify emission sources of greenhouse gases for anthropogenic sources including landfills, coal mines, natural gas production/distribution, cookstoves, and biomass burning. Development of enhanced emission estimates will improve the understanding of atmospheric chemistry and feedback effects, target mitigation opportunities, and ensure cost-effective mitigation strategies.

  11. Natural gas production problems : solutions, methodologies, and modeling.

    SciTech Connect

    Rautman, Christopher Arthur; Herrin, James M.; Cooper, Scott Patrick; Basinski, Paul M.; Olsson, William Arthur; Arnold, Bill Walter; Broadhead, Ronald F.; Knight, Connie D.; Keefe, Russell G.; McKinney, Curt; Holm, Gus; Holland, John F.; Larson, Rich; Engler, Thomas W.; Lorenz, John Clay

    2004-10-01

    Natural gas is a clean fuel that will be the most important domestic energy resource for the first half the 21st centtuy. Ensuring a stable supply is essential for our national energy security. The research we have undertaken will maximize the extractable volume of gas while minimizing the environmental impact of surface disturbances associated with drilling and production. This report describes a methodology for comprehensive evaluation and modeling of the total gas system within a basin focusing on problematic horizontal fluid flow variability. This has been accomplished through extensive use of geophysical, core (rock sample) and outcrop data to interpret and predict directional flow and production trends. Side benefits include reduced environmental impact of drilling due to reduced number of required wells for resource extraction. These results have been accomplished through a cooperative and integrated systems approach involving industry, government, academia and a multi-organizational team within Sandia National Laboratories. Industry has provided essential in-kind support to this project in the forms of extensive core data, production data, maps, seismic data, production analyses, engineering studies, plus equipment and staff for obtaining geophysical data. This approach provides innovative ideas and technologies to bring new resources to market and to reduce the overall environmental impact of drilling. More importantly, the products of this research are not be location specific but can be extended to other areas of gas production throughout the Rocky Mountain area. Thus this project is designed to solve problems associated with natural gas production at developing sites, or at old sites under redevelopment.

  12. Production of hydrogen by thermocatalytic cracking of natural gas

    SciTech Connect

    Muradov, N.Z.

    1995-09-01

    It is universally accepted that in the next few decades hydrogen production will continue to rely on fossil fuels (primarily, natural gas). On the other hand, the conventional methods of hydrogen production from natural gas (for example, steam reforming) are complex multi-step processes. These processes also result in the emission of large quantities of CO{sub 2} into the atmosphere that produce adverse ecological effects. One alternative is the one-step thermocatalytic cracking (TCC) (or decomposition) of natural gas into hydrogen and carbon. Preliminary analysis indicates that the cost of hydrogen produced by thermal decomposition of natural gas is somewhat lower than the conventional processes after by-product carbon credit is taken. In the short term, this process can be used for on-site production of hydrogen-methane mixtures in gas-filling stations and for CO{sub x}-free production of hydrogen for fuel cell driven prime movers. The experimental data on the thermocatalytic cracking of methane over various catalysts and supports in a wide range of temperatures (500-900{degrees}C) are presented in this paper. Two types of reactors were designed and built at FSEC: continuous flow and pulse fix bed catalytic reactors. The temperature dependence of the hydrogen production yield using oxide type catalysts was studied. Alumina-supported Ni- and Fe-catalysts demonstrated relatively high efficiency in the methane cracking reaction at moderate temperatures (600-800{degrees}C). Kinetic curves of hydrogen production over metal and metal oxide catalysts at different temperatures are presented in the paper. Fe-catalyst demonstrated good stability (for several hours), whereas alumina-supported Pt-catalyst rapidly lost its catalytic activity.

  13. Applications of horizontal well completions to gas-productive formations

    SciTech Connect

    Hill, R.E.; Peterson, R.E.; Middlebrook, M.I. ); Aslakson, J.K. )

    1993-08-01

    The Gas Research Institute (GRI) has initiated a project to determine the reservoir characteristics and appropriate horizontal well designs in various gas-productive formations. The goal of the project is to evaluate horizontal completions as a means of reducing unit production costs in comparison to vertical well-completion methods. Three gas-productive formations were evaluated in the initial phase of the project: the Mancos B on the Douglas Creek arch in northwestern Colorado; the Davis Sand in the Fort Worth basin; and the Barnett Shale, also in the Fort Worth basin. Geologic and engineering data from vertical wells were collected for each formation and used to strategically plan offset horizontal wells. Specifically, information was gathered to characterize the natural and induced fractures, model the reservoirs, and establish a production baseline for each reservoir. The next phase involved GRI participation in the drilling of the three offset horizontal wells with three independent producers. A 1500-ft horizontal section was air drilled across the Mancos B; a 2000-ft horizontal well was air drilled in the Davis sandstone; and a 2000-ft horizontal section was fluid drilled across the 300-ft-thick Barnett Shale. Each of the horizontal wells exhibit varying reservoir characteristics and associated gas production.

  14. Development of computer simulations for landfill methane recovery

    SciTech Connect

    Massmann, J.W.; Moore, C.A.; Sykes, R.M.

    1981-12-01

    Two- and three-dimensional finite-difference computer programs simulating methane recovery systems in landfills have been developed. These computer programs model multicomponent combined pressure and diffusional flow in porous media. Each program and the processes it models are described in this report. Examples of the capabilities of each program are also presented. The two-dimensional program was used to simulate methane recovery systems in a cylindrically shaped landfill. The effects of various pump locations, geometries, and extraction rates were determined. The three-dimensional program was used to model the Puente Hills landfill, a field test site in southern California. The biochemical and microbiological details of methane generation in landfills are also given. Effects of environmental factors, such as moisture, oxygen, temperature, and nutrients on methane generation are discussed and an analytical representation of the gas generation rate is developed.

  15. Some modern notions on oil and gas reservoir production regulation

    SciTech Connect

    Lohrenz, J.; Monash, E.A.

    1980-05-21

    The historic rhetoric of oil and gas reservoir production regulations has been burdened with misconceptions. One was that most reservoirs are rate insensitive. Another was that a reservoir's decline is primarily a function of reservoir mechaism rather than a choice unconstrained by the laws of physics. Relieved of old notions like these, we introduce some modern notions, the most basic being that production regulation should have the purpose of obtaining the highest value from production per irreversible diminution of thermodynamically available energy. The laws of thermodynamics determine the available energy. What then is value. Value may include contributions other than production per se and purely monetary economic outcomes.

  16. BUILDING MATERIALS MADE FROM FLUE GAS DESULFURIZATION BY-PRODUCTS

    SciTech Connect

    Michael W. Grutzeck; Maria DiCola; Paul Brenner

    2006-03-30

    Flue gas desulphurization (FGD) materials are produced in abundant quantities by coal burning utilities. Due to environmental restrains, flue gases must be ''cleaned'' prior to release to the atmosphere. They are two general methods to ''scrub'' flue gas: wet and dry. The choice of scrubbing material is often defined by the type of coal being burned, i.e. its composition. Scrubbing is traditionally carried out using a slurry of calcium containing material (slaked lime or calcium carbonate) that is made to contact exiting flue gas as either a spay injected into the gas or in a bubble tower. The calcium combined with the SO{sub 2} in the gas to form insoluble precipitates. Some plants have been using dry injection of these same materials or their own Class C fly ash to scrub. In either case the end product contains primarily hannebachite (CaSO{sub 3} {center_dot} 1/2H{sub 2}O) with smaller amounts of gypsum (CaSO{sub 4} {center_dot} 2H{sub 2}O). These materials have little commercial use. Experiments were carried out that were meant to explore the feasibility of using blends of hannebachite and fly ash mixed with concentrated sodium hydroxide to make masonry products. The results suggest that some of these mixtures could be used in place of conventional Portland cement based products such as retaining wall bricks and pavers.

  17. Reactive oxygen species production and discontinuous gas exchange in insects

    PubMed Central

    Boardman, Leigh; Terblanche, John S.; Hetz, Stefan K.; Marais, Elrike; Chown, Steven L.

    2012-01-01

    While biochemical mechanisms are typically used by animals to reduce oxidative damage, insects are suspected to employ a higher organizational level, discontinuous gas exchange mechanism to do so. Using a combination of real-time, flow-through respirometry and live-cell fluorescence microscopy, we show that spiracular control associated with the discontinuous gas exchange cycle (DGC) in Samia cynthia pupae is related to reactive oxygen species (ROS). Hyperoxia fails to increase mean ROS production, although minima are elevated above normoxic levels. Furthermore, a negative relationship between mean and mean ROS production indicates that higher ROS production is generally associated with lower . Our results, therefore, suggest a possible signalling role for ROS in DGC, rather than supporting the idea that DGC acts to reduce oxidative damage by regulating ROS production. PMID:21865257

  18. Separation of flue-gas scrubber sludge into marketable products. Second year, third quarterly technical progress report, March 1, 1995--May 31, 1995

    SciTech Connect

    Kawatra, S.K.; Eisele, T.C.

    1995-06-01

    To reduce their sulfur emissions, many coal-fired electric power plants use wet flue-gas scrubbers. These scrubbers convert sulfur oxides into solid sulfate and sulfite sludge, which must then be disposed of This sludge is a result of reacting limestone with sulfur dioxide to precipitate calcium sulfite and calcium sulfate. It consists of calcium sulfite (CaSO{sub 3}{sm_bullet}0.5H{sub 2}O), gypsum (CaSO{sub 4}{sm_bullet}2H{sub 2}O), and unreacted limestone (CaCO{sub 3}) or lime (Ca(OH){sub 2}), with miscellaneous objectionable impurities such as iron oxides, silica, and magnesium, sodium, and potassium oxides or salts. These impurities prevent many sludges from being utilized as a replacement for natural gypsum, and as a result they must be disposed of in landfills, which presents a serious disposal problem. This project is studying the characteristics of flue-gas scrubber sludges from several sources. Knowledge of scrubber sludge characteristics is necessary for the development of purification technologies which will make it possible to directly utilize scrubber sludges rather than landfilling them. This purification will consist of minimal-reagent froth flotation, using the surface properties of the particles of unreacted limestone to remove them and their associated impurities from the material, leaving a purified calcium sulfite/gypsum product.

  19. Separation of flue-gas scrubber sludge into marketable products. Second year, second quarterly technical progress report, Quarter No. 6, December 1, 1994--February 28, 1995

    SciTech Connect

    KAwatra, S.K.; Eisele, T.C.

    1995-03-01

    To reduce their sulfur emissions, many coal-fired electric power plants use wet flue-gas scrubbers. These scrubbers convert sulfur oxides into solid sulfate and sulfite sludge, which must then be disposed of. This sludge is a result of reacting limestone with sulfur dioxide to precipitate calcium sulfite and calcium sulfate. It consists of calcium sulfite (CaSO{sub 3}{sm_bullet}0.5H{sub 2}O), gypsum (CaSO{sub 4}{sm_bullet}2H{sub 2}O), and unreacted limestone (CaCO{sub 3}) or lime (Ca(OH){sub 2}), with miscellaneous objectionable impurities such as iron oxides, silica, and magnesium, sodium, and potassium oxides or salts. These impurities prevent many sludges from being utilized as a replacement for natural gypsum, and as a result they must be disposed of in landfills, which presents a serious disposal problem. This project is studying the characteristics of flue-gas scrubber sludges from several sources, which is necessary for the development of purification technologies which will make it possible to directly utilize scrubber sludges rather than landfilling them. This purification will consist of minimal-reagent froth flotation, using the surface properties of the particles of unreacted limestone to remove them and their associated impurities from the material, leaving a purified calcium sulfite/gypsum product.

  20. Short-term landfill methane emissions dependency on wind.

    PubMed

    Delkash, Madjid; Zhou, Bowen; Han, Byunghyun; Chow, Fotini K; Rella, Chris W; Imhoff, Paul T

    2016-09-01

    Short-term (2-10h) variations of whole-landfill methane emissions have been observed in recent field studies using the tracer dilution method for emissions measurement. To investigate the cause of these variations, the tracer dilution method is applied using 1-min emissions measurements at Sandtown Landfill (Delaware, USA) for a 2-h measurement period. An atmospheric dispersion model is developed for this field test site, which is the first application of such modeling to evaluate atmospheric effects on gas plume transport from landfills. The model is used to examine three possible causes of observed temporal emissions variability: temporal variability of surface wind speed affecting whole landfill emissions, spatial variability of emissions due to local wind speed variations, and misaligned tracer gas release and methane emissions locations. At this site, atmospheric modeling indicates that variation in tracer dilution method emissions measurements may be caused by whole-landfill emissions variation with wind speed. Field data collected over the time period of the atmospheric model simulations corroborate this result: methane emissions are correlated with wind speed on the landfill surface with R(2)=0.51 for data 2.5m above ground, or R(2)=0.55 using data 85m above ground, with emissions increasing by up to a factor of 2 for an approximately 30% increase in wind speed. Although the atmospheric modeling and field test are conducted at a single landfill, the results suggest that wind-induced emissions may affect tracer dilution method emissions measurements at other landfills. PMID:26896003

  1. Spatial delineation of natural fractures and relation to gas production

    SciTech Connect

    Caramanica, F.P.; Hill, D.G.

    1994-12-31

    In a Gas Research Institute sponsored study, enhanced formation image analysis was performed on twelve wells in the Antrim Shale, Michigan Basin. The analysis revealed that the abundance of open and partially open fractures as well as their degree of interconnection are controlling factors in gas production. Borehole maps show the interconnection with reference to the borehole. A fracture factor (Z{sub f}) was derived and plotted against gas flow rates for nine wells. Six wells treated with a single stage stimulation show a linear relationship between (Z{sub f}) and Q. Two were stimulated with a two-stage treatment and produced more gas than single-stage wells with comparable values of Z{sub f}. The methods of fracture analysis derived for the Antrim Shale should have immediate practical application to other unconventional and tight reservoir rocks.

  2. Environmental Compliance for Oil and Gas Exploration and Production

    SciTech Connect

    Hansen, Christine

    1999-10-26

    The Appalachian/Illinois Basin Directors is a group devoted to increasing communication among the state oil and gas regulatory agencies within the Appalachian and Illinois Basin producing region. The group is comprised of representatives from the oil and gas regulatory agencies from states in the basin (Attachment A). The directors met to discuss regulatory issues common to the area, organize workshops and seminars to meet the training needs of agencies dealing with the uniqueness of their producing region and perform other business pertinent to this area of oil and gas producing states. The emphasis of the coordinated work was a wide range of topics related to environmental compliance for natural gas and oil exploration and production.

  3. Aeration of the teuftal landfill: Field scale concept and lab scale simulation.

    PubMed

    Ritzkowski, Marco; Walker, Beat; Kuchta, Kerstin; Raga, Roberto; Stegmann, Rainer

    2016-09-01

    Long lasting post-closure care (PCC) is often the major financial burden for operators of municipal solid waste (MSW) landfills. Beside costs for the installation and maintenance of technical equipment and barriers, in particular long term treatment of leachate and landfill gas has to be paid from capital surplus. Estimations based on laboratory experiments project time periods of many decades until leachate quality allows for direct discharge (i.e. no need for further purification). Projections based on leachate samples derived from the last 37years for 35 German landfills confirm these assumption. Moreover, the data illustrate that in particular ammonium nitrogen concentrations are likely to fall below limit values only after a period of 300years. In order to avoid long lasting PCC the operator of Teuftal landfill, located in the Swiss canton Bern, decided to biologically stabilize the landfill by means of a combined in situ aeration and moisturization approach. In December 2014 the aeration started at a landfill section containing approximately 30% of the total landfill volume. From summer 2016 onwards the remaining part of the landfill will be aerated. Landfill aeration through horizontal gas and leachate drains is carried out for the first time in field scale in Europe. The technical concept is described in the paper. Parallel to field scale aeration, investigations for the carbon and nitrogen turnover are carried out by means of both simulated aerated landfills and simulated anaerobic landfills. The results presented in this paper demonstrate that aeration is capable to enhance, both carbon mobilization and discharge via the gas phase. This effect comes along with a significant increase in bio-stabilization of the waste organic fraction, which positively affects the landfill emission behavior in the long run. In terms of leachate pollution reduction it could be demonstrated that the organic load decrease fast and widely independent of the adjusted aeration

  4. Aeration of the teuftal landfill: Field scale concept and lab scale simulation.

    PubMed

    Ritzkowski, Marco; Walker, Beat; Kuchta, Kerstin; Raga, Roberto; Stegmann, Rainer

    2016-09-01

    Long lasting post-closure care (PCC) is often the major financial burden for operators of municipal solid waste (MSW) landfills. Beside costs for the installation and maintenance of technical equipment and barriers, in particular long term treatment of leachate and landfill gas has to be paid from capital surplus. Estimations based on laboratory experiments project time periods of many decades until leachate quality allows for direct discharge (i.e. no need for further purification). Projections based on leachate samples derived from the last 37years for 35 German landfills confirm these assumption. Moreover, the data illustrate that in particular ammonium nitrogen concentrations are likely to fall below limit values only after a period of 300years. In order to avoid long lasting PCC the operator of Teuftal landfill, located in the Swiss canton Bern, decided to biologically stabilize the landfill by means of a combined in situ aeration and moisturization approach. In December 2014 the aeration started at a landfill section containing approximately 30% of the total landfill volume. From summer 2016 onwards the remaining part of the landfill will be aerated. Landfill aeration through horizontal gas and leachate drains is carried out for the first time in field scale in Europe. The technical concept is described in the paper. Parallel to field scale aeration, investigations for the carbon and nitrogen turnover are carried out by means of both simulated aerated landfills and simulated anaerobic landfills. The results presented in this paper demonstrate that aeration is capable to enhance, both carbon mobilization and discharge via the gas phase. This effect comes along with a significant increase in bio-stabilization of the waste organic fraction, which positively affects the landfill emission behavior in the long run. In terms of leachate pollution reduction it could be demonstrated that the organic load decrease fast and widely independent of the adjusted aeration

  5. Offsite commercial disposal of oil and gas exploration and production waste :availability, options, and cost.

    SciTech Connect

    Puder, M. G.; Veil, J. A.

    2006-09-05

    A survey conducted in 1995 by the American Petroleum Institute (API) found that the U.S. exploration and production (E&P) segment of the oil and gas industry generated more than 149 million bbl of drilling wastes, almost 18 billion bbl of produced water, and 21 million bbl of associated wastes. The results of that survey, published in 2000, suggested that 3% of drilling wastes, less than 0.5% of produced water, and 15% of associated wastes are sent to offsite commercial facilities for disposal. Argonne National Laboratory (Argonne) collected information on commercial E&P waste disposal companies in different states in 1997. While the information is nearly a decade old, the report has proved useful. In 2005, Argonne began collecting current information to update and expand the data. This report describes the new 2005-2006 database and focuses on the availability of offsite commercial disposal companies, the prevailing disposal methods, and estimated disposal costs. The data were collected in two phases. In the first phase, state oil and gas regulatory officials in 31 states were contacted to determine whether their agency maintained a list of permitted commercial disposal companies dedicated to oil. In the second stage, individual commercial disposal companies were interviewed to determine disposal methods and costs. The availability of offsite commercial disposal companies and facilities falls into three categories. The states with high oil and gas production typically have a dedicated network of offsite commercial disposal companies and facilities in place. In other states, such an infrastructure does not exist and very often, commercial disposal companies focus on produced water services. About half of the states do not have any industry-specific offsite commercial disposal infrastructure. In those states, operators take their wastes to local municipal landfills if permitted or haul the wastes to other states. This report provides state-by-state summaries of the

  6. Trace gas flux from container production of woody landscape plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The agriculture industry is a large source of greenhouse gas (GHG) emissions which are widely believed to be causing increased global temperatures. Reduction of these emissions has been heavily researched, with most of the work focusing on row crop and animal production sectors. Little attention has...

  7. Low Carbon Technology Options for the Natural Gas Electricity Production

    EPA Science Inventory

    The ultimate goal of this task is to perform environmental and economic analysis of natural gas based power production technologies (different routes) to investigate and evaluate strategies for reducing emissions from the power sector. It is a broad research area. Initially, the...

  8. A field-validated model for landfill methane emissions inclusive of seasonal methane oxidation

    NASA Astrophysics Data System (ADS)

    Bogner, J. E.; Spokas, K.; Chanton, J.

    2010-12-01

    In addition to natural wetlands, atmospheric methane (CH4) has multiple anthropogenic sources with high uncertainties, including rice production, ruminant animals, natural gas leakages, biomass burning, and landfills. For an improved IPCC Tier III methodology for landfill CH4 emissions in California, we have developed a new science-based, field-validated inventory model which decouples emissions from a historical reliance on a theoretical first order kinetic model for CH4 generation potential. The model (CALMIM, CAlifornia Landfill Methane Inventory Model) is a freely-available JAVA tool which estimates net CH4 emissions to the atmosphere for any landfill cover soil over a typical annual cycle, including (1) the effect of engineered gas extraction; (2) the physical effects of daily, intermediate, and final cover materials to retard emissions; and (3) seasonal soil moisture and temperature effects on both gaseous transport and methanotrophic CH4 oxidation. Linking site-specific data with existing globally-validated USDA models for annual climate and soil microclimate (Global TempSim; Global RainSim; Solarcalc; STM2), this model relies on 1-D diffusion as the major driver for emissions. Importantly, unlike current inventory methods based on modeled generation, the driving force for emissions (e.g., the CH4 concentration gradient) can be directly compared to field data. Methane oxidation is scaled to maximum rates over the full range of moisture and temperature conditions based on extensive supporting laboratory studies using California landfill cover soils. Field validation included meteorological data, soil moisture/temperature measurements, and seasonal (wet/dry) CH4 emissions & oxidation measurements for daily, intermediate, and final cover soils over two annual cycles at a northern (Monterey County) and southern California (Los Angeles County) landfill. The model accurately predicted soil temperature and moisture trends for individual cover materials with

  9. Geochemical processes in landfills

    NASA Astrophysics Data System (ADS)

    Förstner, Ulrich; Kersten, Michael; Wienberg, Reinhard

    The present review focusses on the qualitative long-term perspectives of processes and mechanisms controlling the interactions of critical pollutants with organic and inorganic substrates both in "reactor landfills" and in deposits, which already consist of rock-like material ("final storage quality"). The behavior of pollutants in landfills is determined by the chemistry of interstitial solutions, i.e. by pH and redox conditions, and concentration of inorganic and organic ligands; in "reactor landfills" these conditions are widely variable as a result of biochemical reactions, while "final storage quality" implies less variations of chemical interactions. In both alternatives, however, prediction of short- and long-term effects on groundwater quality should be based on the proportion of "active species" of compounds ("mobility concept"). Qualitative assessment of potentially mobile pollutants may involve a controlled significative intensivation of important parameters such as pH-values. Using sequential extraction rearrangements of specific solid "phases" can be evaluated prior to the actual remobilisation of the pollutant into the dissolved phase. From a geochemical point of view the "reactor landfill" is characterized by labile conditions during the initial aerobic and acid anaerobic phases, the former mainly due to uncontrolled interactions with organic solutes. On the other hand, final storage quality, which is defined by the composition of earth crust material, in most cases is not attained by simple incineration of municipal waste, i.e. by reduction of organic fractions only. There is, in particular, the problem of easily soluble minerals, such as chlorides. Nonetheless the type of inorganic residue deposits will increasingly receive prevalence as a method of final storage for municipal wastes in the future.

  10. Fate of chemical warfare agents and toxic industrial chemicals in landfills.

    PubMed

    Bartelt-Hunt, Shannon L; Barlaz, Morton A; Knappe, Detlef R U; Kjeldsen, Peter

    2006-07-01

    One component of preparedness for a chemical attack is planning for the disposal of contaminated debris. To assess the feasibility of contaminated debris disposal in municipal solid waste (MSW) landfills, the fate of selected chemical warfare agents (CWAs) and toxic industrial chemicals (TICs) in MSW landfills was predicted with a mathematical model. Five blister agents [sulfur mustard (HD), nitrogen mustard (HN-2), lewisite (L), ethyldichloroarsine (ED), and phosgene oxime (CX)], eight nerve agents [tabun (GA), sarin (GB), soman (GD), GE, GF, VX, VG, and VM], one riot-control agent [CS], and two TICs [furan and carbon disulfide] were studied. The effects of both infiltration (climate) and contaminant biodegradability on fate predictions were assessed. Model results showed that hydrolysis and gas-phase advection were the principal fate pathways for CWAs and TICs, respectively. Apart from CX and the TICs, none of the investigated compounds was predicted to persist in a landfill for more than 5 years. Climate had little impact on CWA/TIC fate, and biodegradability was only important for compounds with long hydrolysis half-lives. Monte Carlo simulations were performed to assess the influence of uncertainty in model input parameters on CWA/TIC fate predictions. Correlation analyses showed that uncertainty in hydrolysis rate constants was the primary contributor to variance of CWA fate predictions, while uncertainty in the Henry's Law constant and landfill gas-production rate accounted for most of the variance of TIC fate predictions. CWA hydrolysates were more persistent than the parent CWAs, but limited information is available on abiotic or biotic transformation rates for these chemicals. PMID:16856738

  11. Phytoremediation of landfill leachate

    SciTech Connect

    Jones, D.L. . E-mail: d.jones@bangor.ac.uk; Williamson, K.L.; Owen, A.G.

    2006-07-01

    Leachate emissions from landfill sites are of concern, primarily due to their toxic impact when released unchecked into the environment, and the potential for landfill sites to generate leachate for many hundreds of years following closure. Consequently, economically and environmentally sustainable disposal options are a priority in waste management. One potential option is the use of soil-plant based remediation schemes. In many cases, using either trees (including short rotation coppice) or grassland, phytoremediation of leachate has been successful. However, there are a significant number of examples where phytoremediation has failed. Typically, this failure can be ascribed to excessive leachate application and poor management due to a fundamental lack of understanding of the plant-soil system. On balance, with careful management, phytoremediation can be viewed as a sustainable, cost effective and environmentally sound option which is capable of treating 250 m{sup 3} ha{sup -1} yr{sup -1}. However, these schemes have a requirement for large land areas and must be capable of responding to changes in leachate quality and quantity, problems of scheme establishment and maintenance, continual environmental monitoring and seasonal patterns of plant growth. Although the fundamental underpinning science is well understood, further work is required to create long-term predictive remediation models, full environmental impact assessments, a complete life-cycle analysis and economic analyses for a wide range of landfill scenarios.

  12. Landfills in karst terrains

    SciTech Connect

    Hughes, T.H. ); Memon, B.A.; LaMoreaux, P.E. )

    1994-06-01

    State and Federal regulations have established restrictions for location of hazardous waste and municipal, solid waste landfills. Regulations require owners/operators to demonstrate that the hydrogeology has been completely characterized at proposed landfills, and that locations for monitoring wells have been properly selected. Owners/operators are also required to demonstrate that engineering measures have been incorporated in the design of the municipal solid waste landfills, so that the site is not subject to destabilizing events, as a result of location in unstable areas, such as karst terrains. Karst terrains are typically underlain by limestone or dolomite, and may contain a broad continuum of karst features and karst activity. Preliminary investigation of candidate sites will allow ranking of the sites, rejection of some unsuitable sites, and selection of a few sites for additional studies. The complexity of hydrogeologic systems, in karst terrains, mandates thorough hydrogeologic studies to determine whether a specific site is, or can be rendered, suitable for a land disposal facility. Important components of hydrogeologic studies are: field mapping of structural and stratigraphic units; interpretation of sequential aerial photographs; test drilling and geophysical analyses; fracture analyses; seasonal variation in water-levels; spatial variation of hydraulic characteristics of the aquifer and aquiclude; velocity and direction of movement of ground water within aquifers; determination of control for recharge, discharge, and local base level; and evaluation of the effects of man's activities, such as pumping, dewatering and construction.

  13. Applying the Clean Air Act to municipal solid waste landfills

    SciTech Connect

    Heitz, D.R.; Romzick, P.G.

    1998-12-31

    On March 12, 1996, the EPA promulgated the new Source Performance Standards (NSPS) for Municipal Solid Waste (MSW) Landfills, the first federal air regulation specifically for MSW landfills. Landfills subject to this regulation which exceeded the threshold design capacity also became subject to the Title V operating permit program. This began the application of the Clean Air Act (CAA) to most of these nontraditional air sources. Unlike landfills, typical air sources have easily defined input capacities that correspond to potential emissions while the process creates a product or output. All these concepts are difficult and confusing to apply to MSW landfills. Applicability of the following CAA regulations are specifically addressed in this paper: NSPS for MSW landfills; new Source Review (NSR)/Prevention of Significant Deterioration (PSD); landfill Maximum Achievable Control Technologies (MACT); 112(g) Modification of Major Sources of Hazardous Air Pollutants (HAP); 112(r) Accidental Release Prevention; and Title V. Along with summarizing the potential applicability of each, the main issues are presented along with the current information on the regulations.

  14. 78 FR 59650 - Subzone 9F, Authorization of Production Activity, The Gas Company, LLC dba Hawai'i Gas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-27

    ... inviting public comment (78 FR 33051-33052, June 3, 2013). The FTZ Board has determined that no further... Foreign-Trade Zones Board Subzone 9F, Authorization of Production Activity, The Gas Company, LLC dba Hawai'i Gas, (Synthetic Natural Gas), Kapolei, Hawaii On May 22, 2013, The Gas Company, LLC dba...

  15. Alaska North Slope regional gas hydrate production modeling forecasts

    USGS Publications Warehouse

    Wilson, S.J.; Hunter, R.B.; Collett, T.S.; Hancock, S.; Boswell, R.; Anderson, B.J.

    2011-01-01

    A series of gas hydrate development scenarios were created to assess the range of outcomes predicted for the possible development of the "Eileen" gas hydrate accumulation, North Slope, Alaska. Production forecasts for the "reference case" were built using the 2002 Mallik production tests, mechanistic simulation, and geologic studies conducted by the US Geological Survey. Three additional scenarios were considered: A "downside-scenario" which fails to identify viable production, an "upside-scenario" describes results that are better than expected. To capture the full range of possible outcomes and balance the downside case, an "extreme upside scenario" assumes each well is exceptionally productive.Starting with a representative type-well simulation forecasts, field development timing is applied and the sum of individual well forecasts creating the field-wide production forecast. This technique is commonly used to schedule large-scale resource plays where drilling schedules are complex and production forecasts must account for many changing parameters. The complementary forecasts of rig count, capital investment, and cash flow can be used in a pre-appraisal assessment of potential commercial viability.Since no significant gas sales are currently possible on the North Slope of Alaska, typical parameters were used to create downside, reference, and upside case forecasts that predict from 0 to 71??BM3 (2.5??tcf) of gas may be produced in 20 years and nearly 283??BM3 (10??tcf) ultimate recovery after 100 years.Outlining a range of possible outcomes enables decision makers to visualize the pace and milestones that will be required to evaluate gas hydrate resource development in the Eileen accumulation. Critical values of peak production rate, time to meaningful production volumes, and investments required to rule out a downside case are provided. Upside cases identify potential if both depressurization and thermal stimulation yield positive results. An "extreme upside

  16. Brownfields and health risks--air dispersion modeling and health risk assessment at landfill redevelopment sites.

    PubMed

    Ofungwu, Joseph; Eget, Steven

    2006-07-01

    Redevelopment of landfill sites in the New Je