Note: This page contains sample records for the topic landfill gas composition from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Temporal variability of soil gas composition in landfill covers  

Microsoft Academic Search

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

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

2011-01-01

2

Temporal variability of soil gas composition in landfill covers.  

PubMed

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. PMID:21074982

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

2010-11-12

3

Determination of Landfill Gas Composition and Pollutant Emission Rates at Fresh Kills Landfill. Volume 1. Project Report.  

National Technical Information Service (NTIS)

Air emissions of landfill gas pollutants at Fresh Kills Landfill, located in Staten Island, NY, were estimated based on three weeks of sampling of flow, concentration, and flux at passive vents, gas extraction wells, gas collection plant headers, and the ...

1995-01-01

4

Determination of Landfill Gas Composition and Pollutant Emission Rates at Fresh Kills Landfill. Volume 2. Appendices to Project Report.  

National Technical Information Service (NTIS)

Air emissions of landfill gas pollutants at Fresh Kills Landfill, located in Staten Island, NY, were estimated based on three weeks of sampling of flow, concentration, and flux at passive vents, gas extraction wells, gas collection plant headers, and the ...

1995-01-01

5

MUNICIPAL LANDFILL GAS CONDENSATE  

EPA Science Inventory

New regulations relative to air emissions from municipal landfills may require the installation of gas collection systems at landfills. As landfill gas (LFG) is collected, water and other vapors in the gas condense in the system or are purposely removed in the normal treatment of...

6

Determination of landfill gas composition and pollutant emission rates at fresh kills landfill. Volume 1. Project report. Final report  

SciTech Connect

Air emissions of landfill gas pollutants at Fresh Kills Landfill, located in Staten Island, NY, were estimated based on three weeks of sampling of flow, concentration, and flux at passive vents, gas extraction wells, gas collection plant headers, and the landfill surface conducted by Radian Corporation in 1995. Emission rates were estimated for 202 pollutants, including hydrogen sulfide, mercury vapor, speciated volatile organic compounds, methane, and carbon dioxide. Results indicate that large amounts of mercury enter the methane, and carbon dioxide. Results indicate that large amounts of mercury enter the methane recovery plant. Emission factors based on the results are presented.

NONE

1995-12-07

7

Is landfill gas profitable  

Microsoft Academic Search

A California study indicates that commercial development of landfill gas (LFG) offers a potential energy source that warrants greater utilization among the nation's 15,000 landfills. The study idicated that landfills receiving only 300 tons per day of typical residential solid wastes could perhaps support a profitable small-scale recovery system. The public lacks knowledge and know-how, however, and landfill owners and

E. J. Daley; M. J. Dean

1981-01-01

8

Utilization of landfill gas  

Microsoft Academic Search

Landfill gas is produced by the anaerobic decay of organic matter present in municipal solid waste. Raw landfill gas is composed primarily of carbon dioxide (45 vol percent) and methane (55 vol percent) with part-per-million levels of numerous chemical impurities. The U.S. Department of Energy estimates that over 200 billion cubic feet of methane are generated in landfills every year.

Golden

1990-01-01

9

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...

10

Trace gas measurements in landfill gas from closed landfill sites  

Microsoft Academic Search

Five closed landfill sites in the urban area of Wolverhampton, UK were investigated in order to identify the trace components in landfill gas emitted from each site. 17 different compounds were identified in the gas samples following analysis by gas chromatography?mass spectrometry.It appeared that concentrations of carbon disulphide, xylene and toluene detected at the landfill sites were related to site

P. Giess; A. Bush; M. Dye

1999-01-01

11

A new landfill system for cheaper landfill gas purification  

Microsoft Academic Search

This paper introduces a new landfill design and system for landfill gas containment and air ingress prevention. The new system offers more control over the processes of anaerobic digestion and biogas extraction than conventional landfills. As the new system reduces the air ingress the landfill gas purification process becomes cheaper. The new system can be implemented on existing landfills, as

Viktor Popov

2005-01-01

12

LANDFILL GAS PRODUCTION FROM LARGE LANDFILL SIMULATORS  

EPA Science Inventory

Two sizes of landfill simulators or test cells; one set containing approximately 320 kg wet weight of municipal solid wastes (MSW) and the other set containing 2555 kg wet weight of MSW were used to measure the amount and composition of gases produced from MSW under typical landf...

13

Determination of landfill gas composition and pollutant emission rates at fresh kills landfill. Volume 2. Appendices to project report. Final report  

SciTech Connect

Air emissions of landfill gas pollutants at Fresh Kills Landfill, located in Staten Island, NY, were estimated based on three weeks of sampling of flow, concentration, and flux at passive vents, gas extraction wells, gas collection plant headers, and the landfill surface conducted by Radian Corporation in 1995. Emission rates were estimated for 202 pollutants, including hydrogen sulfide, mercury vapor, speciated volatile organic compounds, methane, and carbon dioxide. Results indicate that large amounts of mercury enter the methane, and carbon dioxide. Results indicate that large amounts of mercury enter the methane recovery plant. Emission factors based on the results are presented.

NONE

1995-12-07

14

Landfill Gas Effects on Evapotranspirative Landfill Covers  

Microsoft Academic Search

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

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

2005-01-01

15

Numerical simulation of landfill gas pressure distribution in landfills.  

PubMed

Landfill gas emissions are recognized as one of the three major concerns in municipal solid waste landfills. There are many factors that affect the generation of landfill gas when the landfill is capped. In this article, a model has been developed based on the theory of porous media flow. The model could predict the pressure distribution of landfill gas in landfill, coupling the effect of landfill settlement. According to the simulation analysis of landfill, it was found that: (a) the landfill gas pressure would reach a peak after 1.5 years, then begin to decline, and the rate of decay would slow down after 10 years; (b) the influence radius of the gas wells is limited; (c) the peak value of landfill gas pressure is larger, it appears later and the rate of decay is slower when the landfill settlement is considered in the model; (d) the calculation of excess gas pressure in landfill under different negative pressures of the extraction well is compared between this model and another model, and the results show that the relative pressure distribution form and range are almost the same. PMID:24019384

Xi, Yonghui; Xiong, Hao

2013-09-09

16

Landfill gas recovery in the USA  

Microsoft Academic Search

The source of combustible gas in sanitary landfills, recovery techniques, and processing utilization options are discussed. Landfill gas recovery facilities anticipated to be online in the next two years and the status of planned gas projects in the USA are shown. Federally funded landfill gas research projects are listed. (MHR)

M. Wilkey; E. Zimmerman

1982-01-01

17

Method for testing and monitoring for producing landfill gas  

Microsoft Academic Search

A method of withdrawing landfill gas from a landfill without drawing air into the landfill comprises providing a well in the landfill and withdrawing landfill gas from the well at a plurality of different withdrawal rates. The pressure at a selected region within the landfill is detected while the landfill gas is being withdrawn. A relationship is then established between

R. D. Johnson; R. S. Altmann

1977-01-01

18

Mathematical modelling of landfill gas migration in MSW sanitary landfills.  

PubMed

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. PMID:11954728

Martín, S; Marañón, E; Sastre, H

2001-10-01

19

Landfill-gas-development options  

Microsoft Academic Search

Gas recovery from municipal landfills offers local governments an opportunity to produce energy from a necessary nuisance. New York City is exploring private company development, but municipal and joint-venture development are two other options. New York City receives royalty payments and assumes no risk; the city could receive a greater share of revenues if it contributes to capital costs. In-kind

J. Myers; E. R. Bogardus

1981-01-01

20

19th Annual landfill gas symposium  

SciTech Connect

This document contains the Proceedings of the 19th Annual Landfill Gas Symposium sponsored by the Solid Waste Association of America (SWANA), held on March 19-21, 1996 in Research Triangle Park near Raleigh, North Carolina, USA.The technical papers presented by the speakers cover a broad range of topics of interest to professionals in the municipal solid waste field. Technical sessions on the following subjects were presented: U.S. Landfill Gas Regulations, Control Technologies, Emission and Migration Control, Landfill Gas Generation Models, Field Practices, Case Studies of Landfill Gas Utilization, Global Methane Control, International Perspectives, and Emerging Technologies and Issues in the field of Landfill Gas Utilization.

NONE

1996-11-01

21

Evaluating fugacity models for trace components in landfill gas  

Microsoft Academic Search

A fugacity approach was evaluated to reconcile loadings of vinyl chloride (chloroethene), benzene, 1,3-butadiene and trichloroethylene in waste with concentrations observed in landfill gas monitoring studies. An evaluative environment derived from fictitious but realistic properties such as volume, composition, and temperature, constructed with data from the Brogborough landfill (UK) test cells was used to test a fugacity approach to generating

Sophie Shafi; Andrew Sweetman; Rupert L. Hough; Richard Smith; Alan Rosevear; Simon J. T. Pollard

2006-01-01

22

Gas Movement Through Fractured Landfill Cover Materials.  

National Technical Information Service (NTIS)

Bidirectional gas movement through fractured landfill cover materials is being studied at the Mallard North Landfill in DuPage County, Illinois. Vertical pressure and concentration gradients were monitored during changing meteorological and soil moisture ...

J. E. Bogner C. A. Moore

1986-01-01

23

Landfill Gas Management Plan for the Barycz Municipal Landfill.  

National Technical Information Service (NTIS)

The report is the result of a feasibility study conducted for the Barycz Municipal Landfill, located near the City of Krakow in the Republic of Poland. The feasibility study report describes the alternative methods of LFG (Landfill Gas) management, the su...

1992-01-01

24

Surface emission of landfill gas from solid waste landfill  

Microsoft Academic Search

The surface emission of landfill gas (LFG) was studied to estimate the amount of LFG efflux from solid waste landfills using an air flux chamber. LFG efflux increased as atmospheric temperature increased during the day, and the same pattern for the surface emission was observed for the change of seasons. LFG efflux rate decreased from summer through winter. The average

Jin-Won Park; Ho-Chul Shin

2001-01-01

25

Landfill gas to electricity demonstration project  

NASA Astrophysics Data System (ADS)

Medium Btu methane gas is a naturally occurring by product of anaerobic digestion of landfilled municipal solid waste. The energy potential of landfill gas in New York State is estimated to be 61 trillion Btu's per year or the equivalent of 10 percent of the natural gas used annually in the State. The 18-month Landfill Gas to Electricity Demonstration Project conducted at the Fresh Kills Landfill in Staten Island, New York conclusively demonstrated that landfill gas is an acceptable fuel for producing electricity using an internal combustion engine/generator set. Landfill gas proved to be a reliable and consistent fuel source during a six-month field test program. Engine exhaust emissions were determined to be comparable to that of natural gas and no unusually high corrosion rates on standard pipeline material were found.

Giuliani, A. J.; Cagliostro, L. A.

1982-03-01

26

Landfill gas recovery: a technology status report  

Microsoft Academic Search

Landfill gas, which consists mainly of methane and carbon dioxide, can be recovered and used as a fuel. Processing will upgrade it to a high-Btu gas of pipeline quality. There are more than a dozen commercial landfill-gas recovery facilities in the US at present, all at relatively large sites. The amount of gas produced by a given site is a

R. E. Zimmermann; G. R. Lytwynyshyn; M. L. Wilkey

1983-01-01

27

TECHNOLOGIES OF LANDFILL GAS MANAGEMENT AND UTILIZATION  

Microsoft Academic Search

Aim of this paper is to review different technologies used for managing and utilizing landfill gas, in order to be compared according to their efficiency, costs and emissions. Systems for low generation rates of landfill gas, or low content in methane, include flaring of the extracted gas or its bioxidation using biofilters or non-catalytic oxidation technology. Also the case that

T. Tsatsarelis; A. Karagiannidis; N. Moussiopoulos; G. Perkoulidis

28

Appointment in Sonzay: Landfill gas fueled vehicles  

SciTech Connect

The SITA Group (Paris, France) an international waste management company, wanted to research and develop a means to economically and environmentally reuse the inherent value of its landfill gas. As the owner of more than 100 landfills in France alone--both hazardous and non-hazardous--SITA felt that it had a responsibility to research innovative gas treatment and/or reuse options, particularly as public scrutiny of landfill management practices was on the rise. In a successful pilot program initiated by SITA, landfill gas was reused as biofuel for vehicles in a way that was economically viable and environmentally sound.

Balbo, M.E. [SITA Group, Paris (France)

1997-05-01

29

Demonstration of landfill gas enhancement techniques in landfill simulators  

NASA Astrophysics Data System (ADS)

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.

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

1982-02-01

30

Passive drainage and biofiltration of landfill gas: Australian field trial  

Microsoft Academic Search

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

S. A.. Dever; G. E.. Swarbrick; R. M.. Stuetz

2007-01-01

31

Methane Gas Utilization Project from Landfill at Ellery (NY)  

Microsoft Academic Search

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

Pantelis K. Panteli

2012-01-01

32

Landfill gas activity in New York State  

Microsoft Academic Search

Landfill gas (LFG) recovery in New York State today ranks second to California with eight NYS projects in various stages of development. A research project begun in 1977 at NYC's Fresh Kills landfill on Staten Island catalyzed initial interest in LFG recovery in the state. This four-phase project included determining optimum gas withdrawal rates and recovery well spacings; using raw

Bogardus

2009-01-01

33

Operating a fuel cell using landfill gas  

Microsoft Academic Search

The paper discusses operating a 200-kW phosphoric acid fuel cell using landfill gas (LFG) in Groton, Connecticut. The project is intended to demonstrate the viability of installing, operating, and maintaining a fuel cell operating on LFG at a landfill site. The goals of the project are to evaluate the fuel cell and gas pretreatment unit (GPU) operation, test modifications to

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

1996-01-01

34

LANDFILL GAS ENERGY UTILIZATION: TECHNOLOGY OPTIONS AND CASE STUDIES  

EPA Science Inventory

The report discusses technical, environmental, and other issues associated with using landfill gas as fuel, and presents case studies of projects in the U.S. illustrating some common energy uses. he full report begins by covering basic issues such as gas origin, composition, and ...

35

Evaluating fugacity models for trace components in landfill gas.  

PubMed

A fugacity approach was evaluated to reconcile loadings of vinyl chloride (chloroethene), benzene, 1,3-butadiene and trichloroethylene in waste with concentrations observed in landfill gas monitoring studies. An evaluative environment derived from fictitious but realistic properties such as volume, composition, and temperature, constructed with data from the Brogborough landfill (UK) test cells was used to test a fugacity approach to generating the source term for use in landfill gas risk assessment models (e.g. GasSim). SOILVE, a dynamic Level II model adapted here for landfills, showed greatest utility for benzene and 1,3-butadiene, modelled under anaerobic conditions over a 10 year simulation. Modelled concentrations of these components (95,300 microg m(-3); 43 microg m(-3)) fell within measured ranges observed in gas from landfills (24,300-180,000 microg m(-3); 20-70 microg m(-3)). This study highlights the need (i) for representative and time-referenced biotransformation data; (ii) to evaluate the partitioning characteristics of organic matter within waste systems and (iii) for a better understanding of the role that gas extraction rate (flux) plays in producing trace component concentrations in landfill gas. PMID:16603294

Shafi, Sophie; Sweetman, Andrew; Hough, Rupert L; Smith, Richard; Rosevear, Alan; Pollard, Simon J T

2006-04-05

36

Discuss on the design of MSW landfill gas collection project  

Microsoft Academic Search

Landfill gas (LFG) is the gas generated by waste anaerobic process in landfill, LFG consists of CH4 , CO2 (more than 98% in volume ) and other gases (little bit). LFG is a pollutant and dangers gas for a landfill, and also is a energy. Effectively leading, collecting and using the landfill gas not only can avoid the pollution and

Guo Xiang Xin; Yun Song

37

Landfill Gas Utilization: Options, Benefits, and Barriers.  

National Technical Information Service (NTIS)

Of the more than 6,000 active municipal solid waste landfills in the United States (U.S.), there are 114 landfill gas (LFG) to energy projects. The paper describes the different options for LFG to energy projects and provides statistics on the U.S. LFG in...

S. A. Thorneloe

1992-01-01

38

Bioenergy from landfill gas (LFG) in Taiwan  

Microsoft Academic Search

Greenhouse gases (GHGs) emissions are becoming significant energy and environmental issues relating to municipal solid waste (MSW) deposited in landfills in Taiwan. The nation, although not a Party to the Montreal Protocol and Kyoto Protocol, has diligently striven to mitigate and phase out them. The landfill gas (LFG), which is now considered as a renewable energy with emphasis on electricity

W. T. Tsai

2007-01-01

39

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 ...

40

Landfill gas extraction and purification technologies  

Microsoft Academic Search

The extraction and purification technologies of landfill gas (LFG) from municipal waste continue to generate strong environmental concerns. Historically, the focus of these concerns was an odour in the immediate region of the landfill and the risk of explosions in structures caused by the movement of LFG through soil. While these are still important environmental issues, health risks associated with

Valeriy Bekmuradov

2008-01-01

41

Landfill gas recovery: An analysis of results  

NASA Astrophysics Data System (ADS)

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.

Peterson, J. M.

1982-02-01

42

Landfill gas energy recovery: Turning a liability into an asset  

Microsoft Academic Search

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

1996-01-01

43

Landfill-gas energy utilization: Technology options and case studies. Final report, Mar 91Mar 92  

Microsoft Academic Search

The report discusses technical, environmental, and other issues associated with using landfill gas as fuel, and presents case studies of projects in the U.S. illustrating some common energy uses. The full report begins by covering basic issues such as gas origin, composition, and means of collection; environmental and regulatory background is presented. Properties of landfill gas as a fuel are

D. Augenstein; J. Pacey

1992-01-01

44

Collection and utilization of landfill gas  

Microsoft Academic Search

Since early 1977 the recovery of landfill gas has been studied on a 40-acre portion of a 2908-acre landfill in Staten Island, New York. During the 1st 2 phases of this project, withdrawal tests were conducted, and the results indicate that the optimum withdrawal rate for this site is 50 cubic feet 550-Btu gas\\/min with a spacing of 1 well\\/acre.

Guiliani

1981-01-01

45

Gas generation, transport, and extraction in landfills  

Microsoft Academic Search

A model describing the generation, transport, and extraction of gas in a landfill has been developed. In the model the landfill gas is assumed to be an equimolar mixture of CH[sub 4] and CO[sub 2]. The waste is thought to comprise three classes of materials differing in their degree of biodegradability but all following first-order biodegradation kinetics. The model describes

Sumadhu G. Arigala; Theodore T. Tsotsis; Y. C. Yortsos; J. J. Kattapuram; I. A. Webster

1995-01-01

46

Effects of landfill gas on subtropical woody plants  

NASA Astrophysics Data System (ADS)

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.

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

1991-05-01

47

Landfill Gas Generation and Migration: Review of Current Research II.  

National Technical Information Service (NTIS)

With regard to gas migration, a field investigation is examining bidirectional gas movement through landfill cover materials by processes of pressure and diffusional flow. The overall purpose of the study is to quantify gas loss from the landfill reservoi...

J. Bogner M. Vogt R. Piorkowski

1989-01-01

48

Landfill gas boosted to pipeline quality  

SciTech Connect

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.

Not Available

1984-03-01

49

Passive drainage and biofiltration of landfill gas: Australian field trial  

SciTech Connect

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.

Dever, S.A. [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia) and GHD Pty. Ltd., 10 Bond Street, Sydney, NSW 2000 (Australia)]. E-mail: stuart_dever@ghd.com.au; Swarbrick, G.E. [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)]. E-mail: g.swarbrick@unsw.edu.au; Stuetz, R.M. [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)]. E-mail: r.stuetz@unsw.edu.au

2007-07-01

50

Partitioning Gas Tracer Technology for Measuring Water in Landfills  

NASA Astrophysics Data System (ADS)

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 between the point of tracer injection and tracer extraction because the partitioning tracer is retarded due to water in the landfill. The degree of tracer retardation can be used to determine the average water saturation between the injection and extraction points. This partitioning gas tracer test yields a large-scale estimate of the water saturation, is not affected by solid waste compaction or heterogeneity in the composition of the solid waste, and has been successfully tested in a recent field experiment in soils. We report the results from a series of laboratory experiments designed to evaluate this technology with various trash mixtures. Experimental conditions were selected to mimic the range of moisture conditions that may exist within municipal landfills. The influence of leachate composition and temperature on gas tracer partitioning were also evaluated. In our trash mixtures, the partitioning gas tracer test determined volumetric water contents that were within 12% of actual values. We discuss these data in detail and describe environmental conditions (e.g., temperature variations) that may affect the utility of the partitioning gas tracer test.

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

2002-12-01

51

Soil gas investigations at the Sanitary Landfill  

SciTech Connect

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.

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

1992-07-01

52

Soil gas investigations at the Sanitary Landfill  

SciTech Connect

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.

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

1992-07-01

53

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...

54

Power generation from landfill gas. Proceedings.  

National Technical Information Service (NTIS)

Nine papers and four discussion sessions are presented at a one day meeting on power generation from landfill gas organised for the UK Dept. of Energy. Topics covered include the research and demonstration programs funded by the UK DOE, the trace componen...

J. F. Gorman D. H. Maunder G. E. Richards

1992-01-01

55

Methane gas recovery from sanitary landfills in Southern California  

Microsoft Academic Search

Recent efforts in Southern California to utilize methane gas as a new energy source in an economical and environmentally acceptable way are reviewed. Four basic approaches to utilizing methane gas from landfills are discussed: (1) delivery of low BTU (500 BTU) gas to adjacent interruptible gas consumers, (2) on-site treatment of landfill gas to produce pipeline quality synthetic natural gas,

K. K. Hekimian; W. J. Lockman; J. H. Hirt

1976-01-01

56

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

Microsoft Academic Search

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

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

2008-01-01

57

LANDFILL GAS RECOVERY/UTILIZATION - OPTIONS AND ECONOMICS  

EPA Science Inventory

The paper describes the options and economics for landfill gas utilization. (NOTE: The decomposition of landfilled waste results in a gas that can be either a source of pollution or a resource. f the more than 6000 active municipal solid waste landfills in the U. S., there are 11...

58

Landfill Gas Recovery/Utilization: Options and Economics.  

National Technical Information Service (NTIS)

The decomposition of landfilled waste results in a gas which can be a source of pollution as well as a resource. Of the more than 6,000 active municipal solid waste landfills in the United States (U.S.), there are 114 landfill gas (LFG) energy projects. T...

S. A. Thorneloe

1992-01-01

59

LCA and economic evaluation of landfill leachate and gas technologies  

Microsoft Academic Search

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

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

2011-01-01

60

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...

61

Gas and Leachate from Landfills: Formation, Collection, and Treatment.  

National Technical Information Service (NTIS)

Contents: Introduction to symposium on gas and leachate from landfills: formation, collection, and treatment; Current EPA research activities in solid waste management; Current office of solid waste management programs: landfill activities; Current solid ...

E. J. Genetelli J. Cirello

1976-01-01

62

Funding Landfill Gas Projects. A Guide to State, Federal, and Foundation Resources.  

National Technical Information Service (NTIS)

More than 340 communities, landfill owners and operators, and state officials across the U.S. are learning that landfill gas is an important local and regional resource. To develop landfill gas utilization projects, landfill owners and operators capture l...

2004-01-01

63

Methane Gas Utilization Project from Landfill at Ellery (NY)  

SciTech Connect

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.

Pantelis K. Panteli

2012-01-10

64

Evaluation of landfill gas as an energy source  

NASA Astrophysics Data System (ADS)

The benefits and problems associated with landfill gas recovery were considered by the City of Baltimore, resulting in the structuring and testing of a realistic gas recovery evaluation procedure for use by local governments. The Baltimore methodology is summarized and results of its application to a large landfill in the Baltimore area are presented. The landfill gas generation process potential uses for the recovered gas, and treatment requirements are covered.

1980-12-01

65

An energy perspective on landfill gas  

SciTech Connect

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.

Hutchinson, P.J. (Hutchinson Group, Ltd., Murrysville, PA (United States))

1993-01-01

66

Landfill gas energy recovery: Turning a liability into an asset  

SciTech Connect

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.

Nichols, M. [EPA, Washington, DC (United States)

1996-08-01

67

New Financing Options and Incentives for Landfill Gas Energy  

Microsoft Academic Search

Stakeholders promoting landfill gas (LFG) energy projects are identifying new funding incentives to implement LFG energy (LFGE) projects. This article focuses on how landfills are participating in voluntary carbon and renewable energy markets, and presents case studies from award-winning projects that utilize these funding mechanisms.Landfills participate in the voluntary carbon markets using one of two main mechanisms: on an exchange

Chris Godlove; Amanda R. Singleton

2010-01-01

68

Microbial mitigation of greenhouse gas emissions from landfill cover soils  

Microsoft Academic Search

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

Sung-Woo Lee

2008-01-01

69

Quantifying Uncontrolled Landfill Gas Emissions from Two Florida Landfills.  

National Technical Information Service (NTIS)

The purpose of this study is to evaluate fugitive loss from two different municipal landfills which were reported to be operating as a wet or bioreactor landfill and have an area regarded as a control cell (where no additional liquid was added). Fugitive ...

2009-01-01

70

Making landfill gas into a clean vehicle fuel  

Microsoft Academic Search

Converting landfill gas into compressed natural gas (CNG) for use in vehicles has potential to provide both economic and environmental benefits. The Sanitation Districts of Los Angeles County in 1991 initiated a program to utilize CNG derived from landfill gas as a clean, alternative fuel for the District's fleet vehicles and heavy-duty equipment. The program also envisioned that fuel could

Wheless

2009-01-01

71

Feasibility Study for Utilization of Landfill Gas at the Royalton Road Landfill, Broadview Heights, Ohio. Final Report.  

National Technical Information Service (NTIS)

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 q...

1983-01-01

72

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...

73

BUNCOMBE COUNTY WASTEWATER PRETREATMENT AND LANDFILL GAS TO ENERGY PROJECT  

Microsoft Academic Search

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.

Jon Creighton

2012-01-01

74

Evaluation of Partitioning Gas Tracer Tests for Measuring Water in Landfills  

NASA Astrophysics Data System (ADS)

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 which a vacuum was applied. The results from this test are reported along with an overview of a similar test planned for the bioreactor landfill cells operated by the Yolo County Department of Planning and Public Works.

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

75

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

SciTech Connect

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.

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

1991-09-01

76

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

SciTech Connect

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.

NONE

1997-06-01

77

Landfill Gas Utilization: Database of North American Projects.  

National Technical Information Service (NTIS)

Data landfill-gas (LFG)-to-energy projects have been reported for U.S. landfills and to a lesser extent on Canadian projects. The paper describes the LFG-to-energy industry, providing data on the types of projects in North America, the current energy outp...

S. A. Thorneloe J. G. Pacey

1994-01-01

78

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...

79

Gas production by accelerated in situ bioleaching of landfills  

Microsoft Academic Search

A process for improved gas production and accelerated stabilization of landfills by accelerated in situ bioleaching of organic wastes by acid forming bacteria in substantially sealed landfills, passing the leachate of hydrolysis and liquefaction products of microbial action of the microorganisms with the organic material to an acid phase digester to regenerate the activated culture of acid forming microorganisms for

1982-01-01

80

Landfill gas energy utilization: Technical and nontechnical considerations  

Microsoft Academic Search

The paper discusses technical issues associated with the use of landfill gas (LFG) compared with natural gas, which is the primary fuel used for energy conversion equipment such as internal combustion engines, gas turbines, and fuel cells. LFG is a medium-heating-value fuel containing trace constituents that require gas pretreatment and energy equipment modifications to operate successfully. There are more than

J. G. Pacey; M. R. J. Doorn; S. A. Thorneloe

1994-01-01

81

Impact of using high-density polyethylene geomembrane layer as landfill intermediate cover on landfill gas extraction  

Microsoft Academic Search

Clay is widely used as a traditional cover material for landfills. As clay becomes increasingly costly and scarce, and it also reduces the storage capacity of landfills, alternative materials with low hydraulic conductivity are employed. In developing countries such as China, landfill gas (LFG) is usually extracted for utilization during filling stage, therefore, the intermediate covering system is an important

Zezhi Chen; Huijuan Gong; Mengqun Zhang; Weili Wu; Yu Liu; Jin Feng

2011-01-01

82

LANDFILL GAS AND THE GREENHOUSE EFFECT  

EPA Science Inventory

The paper is an overview of the current understanding of methane emissions from landfills that contribute to global climate change. The factors affecting landfill emissions are described and the uncertainties are identified. There appears to be a consensus in the international co...

83

Gas production from sanitary landfills as a potential energy resource  

Microsoft Academic Search

The rapid increase in the cost of energy has increased interest in the recovery and utilization of sanitary landfill gas at locations throughout the World. These solid waste disposal sites are considered untapped sources of methane gas. If methane is not recovered and utilized, it forms an explosive mixture with oxygen and causes environmental damages. The amount of recoverable gas

Alzuydi

1980-01-01

84

LANDFILL GAS ENERGY UTILIZATION: TECHNICAL AND NON-TECHNICAL CONSIDERATIONS  

EPA Science Inventory

The paper discusses technical issues associated with the use of landfill gas (LFG) compared with natural gas--which is the primary fuel used for energy conversion equipment such as internal combustion engines, gas turbines, and fuel cells. FG is a medium-heating-value fuel contai...

85

Life cycle assessment as a decision support tool for landfill gas-to energy projects  

Microsoft Academic Search

The greenhouse gas (GHG) emissions from MSW landfill, and control methods to eliminate or minimize these impacts including energy recovery from landfill gas (LFG) of MSW landfill in Thailand have been evaluated. Life Cycle Assessment (LCA) is used as the analytical tool to evaluate the environmental consequences of landfilling holistically. The economic implications of the control methods are also briefly

Wanida Wanichpongpan; Shabbir H. Gheewala

2007-01-01

86

Removal and determination of trimethylsilanol from the landfill gas.  

PubMed

The removal and determination of trimethylsilanol (TMSOH) in landfill gas has been studied before and after the special E3000-ITC System. The system works according to principle of temperature swing. The performance of TMSOH and humidity removal was 20% and more than 90%, respectively. The six of active carbons and impinger method were tested on the full-scale landfill in Poland for TMSOH and siloxanes determination. The extraction method and absorption in acetone were used. The concentration of TMSOH and siloxanes were found in range from 23.6 to 29.2 mg/m3 and from 18.0 to 38.9 mg/m3, respectively. The content of TMSOH in biogas originating from landfill was 41% out of all siloxanes. Moreover, the used system is alternative to other existing technique of landfill gas purification. PMID:22033372

Piechota, Grzegorz; Hagmann, Manfred; Buczkowski, Roman

2011-09-08

87

Landfill-gas utilization: Options, benefits, and barriers  

Microsoft Academic Search

Of the more than 6,000 active municipal solid waste landfills in the United States (U.S.), there are 114 landfill gas (LFG) to energy projects. The paper describes the different options for LFG to energy projects and provides statistics on the U.S. LFG industry. The paper also provides an overview of the benefits associated with LFG utilization and identifies some of

Thorneloe

1992-01-01

88

Landfill gas-fired power plant pays cost of operating landfill  

SciTech Connect

This paper reports on recovery of energy from refuse that has become increasingly attractive in the past decade. The continuing urbanization of our society has created major challenges in the disposal of our waste products. Because of public concern over the potential presence of toxins, and for other environmental reasons, management and regulation of active and inactive landfills have become much more stringent and costly. Palos Verdes landfill, owned jointly by the Los Angeles County Sanitation Districts and Los Angeles County, is located about three miles from the Pacific Ocean in the city of Rolling Hills Estates, Calif. The landfill was closed in 1980. The garbage was covered with six to eight feet of soil, and the area was landscaped. Part of this area has already been developed as the South Coast Botanical Gardens and Ernie Howlett Park. The remainder is scheduled to become a golf course. As refuse decays within a landfill, the natural anaerobic biological reaction generates a low-Btu methane gas along with carbon dioxide, known as landfill gas (LFG). The gas also contains other less desirable trace components generated by the decomposing garbage. Uncontrolled, these gases migrate to the surface and escape into the atmosphere where they generate environmental problems, including objectionable odors. The Sanitation Districts have installed a matrix of gas wells and a gas collection system to enable incineration of the gas in flares. This approach reduced aesthetic, environmental and safety concerns. However, emissions from the flares were still a problem. The Sanitation Districts then looked at alternatives to flaring the gas, one of which was electrical generation. Since the Sanitation Districts have no on-site use for thermal energy, power generation for use in the utility grid was deemed the most feasible alternative.

Wallace, I.P.

1991-01-01

89

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...

90

Possibilities of gas utilization with special emphasis on small sanitary landfills  

Microsoft Academic Search

Summary Based on general observations on gas production in sanitary landfills, properties of some important landfill gases are discussed, especially with regard to the potential heat recovery. It has been shown, based on practice oriented considerations, that the utilization of landfill gases can be worthwhile even in small landfills. A scheme has been given which shows all the possibilities for

Mauro Gandolla; Ernst Grabner; Romano Leoni

1982-01-01

91

LANDFILL GAS GENERATION AND RECOVERY IN THAILAND  

Microsoft Academic Search

A relatively limited amount of information is currently available regarding appropriate input parameters for methane generation models for Asian countries. This paper provides an overview of the preliminary findings of the Energy and Environmental Engineering Centre at the Kasetsart University, based on their work at the Kamphangsaen Landfill in Thailand. Work on this project has also been supported by the

Boonma Panpradist

92

Evaluation of Partitioning Gas Tracer Tests for Measuring Water in Landfills  

Microsoft Academic Search

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

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

2003-01-01

93

Hazard ranking of landfills using fuzzy composite programming  

SciTech Connect

The environmental and health risks posed by unregulated landfills are concerns that must be addressed. These concerns have been highlighted with the recent reauthorization of the Resource Conservation and Recovery Act (RCRA) Subtitle D, which requires the closure of all unregulated landfills by October 1993. Most communities with unregulated landfills do not have the financial resources to conduct full-scale risk assessments. This paper proposes the use of a multicriteria assessment system as a tool for screening and prioritizing unregulated disposal sites according to their level of environmental and health hazard. This multicriteria assessment system uses a technique termed composite programming and allows for the use of imprecise information through fuzzy set theory. Using this methodology in landfill hazard assessment allows for the consideration of uncertainty associated with parameters that impact the hazard assessment. Additionally, the user can specify hazards that are most detrimental. The complexity of input parameters (first level indicators) were selected to minimize the time required to collect and/or analyze site-specific data. The result obtained in the assessment is a fuzzy number that indicates the most likely range of hazard and the largest likely range of hazard relative to the best and worst case scenarios. A case study, in which this method is applied to a small rural landfill, is presented to illustrate the methodology.

Hagemeister, M.E. [Terracon Environmental, Inc., Omaha, NE (United States); Jones, D.D.; Woldt, W.E. [Univ. of Nebraska, Lincoln, NE (United States)

1996-04-01

94

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

SciTech Connect

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).

VANDOR,D.

1999-03-01

95

Landfill gas energy utilization: Technical and nontechnical considerations  

NASA Astrophysics Data System (ADS)

The paper discusses technical issues associated with the use of landfill gas (LFG) compared with natural gas, which is the primary fuel used for energy conversion equipment such as internal combustion engines, gas turbines, and fuel cells. LFG is a medium-heating-value fuel containing trace constituents that require gas pretreatment and energy equipment modifications to operate successfully. There are more than 100 LFG-to-energy projects in the U.S., and their developers and operators have found different ways to minimize the potential problems associated with LFG utilization. The paper also gives an overview of developers and operators of these projects, data of European projects, nontechnical issues such as project barriers and incentives, the relationship between LFG delivery and energy output, active landfill gas developers, and insights on project decision making.

Pacey, J. G.; Doorn, M. R. J.; Thorneloe, S. A.

1994-03-01

96

Guidance Note on Landfill Gas Capture and Utilization  

Microsoft Academic Search

As part of the Inter-American Development Bank (IDB) strategy to promote good practices in municipal solid waste (MSW) management and knowledge sharing activities in Latin America and the Caribbean (LAC), the IDB Water and Sanitation Division (INE\\/WSA) is developing a MSW management working paper series. The first paper, which focuses on landfill gas (LFG) capture from MSW and utilization, is

Horacio Terraza; Hans Willumsen

2010-01-01

97

A utility perspective on methane gas recovery from landfills  

Microsoft Academic Search

Over the past decade since the 1973 oil embargo, there has been increased interest in sources of energy that are renewable and provide beneficial environmental effects. At the same time, concern has been growing regarding waste disposal methods, past and present. The use of methane gas produced in landfills is becoming widely recognized in our nation as being one partial

J. Pardus; A. Quade

1983-01-01

98

Gas emissions from landfills and their contributions to global warming  

Microsoft Academic Search

The contribution of methane from UK landfills is described in relation to total gas emissions to the atmosphere and how these have been shown to contribute to global warming. The known effects that methane has on the atmosphere are reviewed and the relationship to those effects caused by other greenhouse gases is described. A methodology utilized in assessing the quantity

N. Gardner; B. J. W. Manley; J. M. Pearson

1993-01-01

99

A catalytic\\/sorption hybrid process for landfill gas cleanup  

Microsoft Academic Search

Landfill gas (LFG) consists primarily of methane and carbon dioxide and a few percent of Oâ, Nâ, and HâO. It also contains numerous other organic compounds, many containing halogens and sulfur. Such compounds besides being potentially toxic to human, animal, and plant life, in addition present challenges to the further processing of LFG. For example, halogen- and sulfur-containing compounds in

Chuanteng He; R. G. Minet; T. T. Tsotsis; D. J. Herman

1997-01-01

100

LANDFILL GAS UTILIZATION--OPTIONS, BENEFITS, AND BARRIERS  

EPA Science Inventory

The paper describes the options for landfill-gas (LFG)-to-energy projects and provides statistics on the U. S. LFG industry. It also provides an overview of the benefits associated with LFG utilization and identifies some of the current barriers in the U. S. that affect LFG utili...

101

LANDFILL GAS UTILIZATION - DATABASE OF NORTH AMERICAN PROJECTS  

EPA Science Inventory

The paper summarizes data in an updated and expanded database for North American landfill-gas (LFG)-to-energy projects. t provides summary statistics, including a list of current projects, trends in conversion technologies, and a list of major developers, energy equipment supplie...

102

Landfill gas utilization at a waste water treatment plant  

Microsoft Academic Search

The Central Contra Costa Sanitary District (CCCSD) in Contra Costa County, California, has been using landfill gas (LFG) as a major source of energy in its wastewater treatment plant for approximately one and half years. A discussion of the CCCSD LFG project is presented, including its origin, highlights of the initial feasibility study, the design of the selected LFG alternative,

C. L. Weddle; H. S. McDonald; W. R. Howard

1983-01-01

103

Fuel-cell energy recovery from landfill gas  

Microsoft Academic Search

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 the application because it is the cleanest energy conversion technology available. The paper discusses the results of Phase I, a conceptual

G. J. Sandelli; R. J. Spiegel

1992-01-01

104

The landfill gas activity of the IEA bioenergy agreement  

Microsoft Academic Search

Landfill gas (LFG) is a renewable source of useful energy. Its world wide annual energy potential is in the range of a few hundred TWh. Today it is only marginally exploited. LFG is also an important contributor to the atmospheres CH4-content, it can be estimated to contribute about 25% of the methane coming from anthropogenic sources. In comparison to many

A Lagerkvist

1995-01-01

105

ANALYSIS OF FACTORS AFFECTING METHANE GAS RECOVERY FROM SIX LANDFILLS  

EPA Science Inventory

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 mod...

106

Landfill Gas Cleanup for Carbonate Fuel Cell Power Generation: Final Report  

SciTech Connect

Landfill gas represents a significant fuel resource both in the United States and worldwide. The emissions of landfill gas from existing landfills has become an environmental liability contributing to global warming and causing odor problems. Landfill gas has been used to fuel reciprocating engines and gas turbines, and may also be used to fuel carbonate fuel cells. Carbonate fuel cells have high conversion efficiencies and use the carbon dioxide present in landfill gas as an oxidant. There are, however, a number of trace contaminants in landfill gas that contain chlorine and sulfur which are deleterious to fuel cell operation. Long-term economical operation of fuel cells fueled with landfill gas will, therefore, require cleanup of the gas to remove these contaminants. The overall objective of the work reported here was to evaluate the extent to which conventional contaminant removal processes could be combined.

Steinfeld, G.; Sanderson, R.

1998-02-01

107

Technical and economic assessment of power generation from landfill gas in South Africa  

Microsoft Academic Search

The paper reports on the technical, economic and environmental assessment of stand-alone and grid connected electricity generation from landfill gas in South Africa. Theoretical models are developed in Matlab to calculate the methane production potential of three Western Cape landfill sites in order to assess their suitability for landfill gas to energy (LFGTE) projects. Then Homer package is used to

K. Sekgoele; S. P. Chowdhury

2011-01-01

108

Landfill-gas recovery\\/utilization: Options and economics. Rept. for Mar 91Mar 92  

Microsoft Academic Search

The decomposition of landfilled waste results in a gas which can be a source of pollution as well as a resource. Of the more than 6,000 active municipal solid waste landfills in the United States (U.S.), there are 114 landfill gas (LFG) energy projects. This paper describes the options and economics for LFG utilization, as well as ongoing research associated

Thorneloe

1992-01-01

109

Waste heat recovery from a landfill gas-fired power plant  

Microsoft Academic Search

Waste treatment and management is a certain challenge especially in areas with high population density. One of the options for waste treatment is landfilling, where the amount of municipal waste also produces landfill gas through anaerobic digestion. The heating value of the landfill gas is high enough to use it as a fuel in combustion processes, e.g. in internal combustion

Daniela Gewald; Konstantinos Siokos; Sotirios Karellas; Hartmut Spliethoff

2012-01-01

110

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...

111

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

PubMed

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

Qiu, Gang; Li, Liang; Sun, Hongjun

2013-06-14

112

GAS CHARACTERIZATION, MICROBIOLOGICAL ANALYSIS, AND DISPOSAL OF REFUSE IN GRI (GAS RESEARCH INSTITUTE) LANDFILL SIMULATORS  

EPA Science Inventory

The report describes the termination of a five-year pilot-scale project that evaluated methane production and gas enhancement techniques in sanitary landfills. Sixteen simulated landfills were constructed in 1980 and operated until January 1985. Data collected during this termina...

113

Chemical characterization of odorous gases at a landfill site by gas chromatography–mass spectrometry  

Microsoft Academic Search

The composition of odorous gases emitted from a municipal landfill in the city of Izmir, Turkey was investigated using gas chromatography–mass spectrometry, and these data were examined in relation with the odor concentrations. Several volatile organic compounds (VOCs) were identified and quantified at five sampling sites in May and September 2005. Detected VOCs were monoaromatics (0.09–47.42?gm?3), halogenated compounds (0.001–62.91?gm?3), aldehydes

Faruk Dincer; Mustafa Odabasi; Aysen Muezzinoglu

2006-01-01

114

Studies of soil gas, gas generation, and shallow microbial activity at Mallard North Landfill, Dupage County, Illinois  

Microsoft Academic Search

Three types of investigations at the Mallard North Landfill during the last five years have led to the development of useful field and laboratory techniques for better understanding gas generation, gas migration, and shallow microbial processes at any landfill. This paper summarizes the techniques with reference to representative results from Mallard North and discusses their general applicability to landfill site

J. E. Bogner; M. Vogt; R. M. Miller

1990-01-01

115

Evaluation Test on a Landfill Gas-Fired Flare at the Los Angeles County Sanitation District's Puente Hills Landfill Facility.  

National Technical Information Service (NTIS)

A cooperative test program was conducted from February 18 through February 21, 1986, by Air Resources Board (ARB) and South Coast Air Quality Management District (SCAQMD) staff to evaluate the gaseous constituents from untreated landfill gas used to fuel ...

1986-01-01

116

Testing of fuel cells to recover energy from landfill gas: Groton landfill. Final report, July 1995July 1997  

Microsoft Academic Search

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 Northeast Utilities at the Groton, CT, landfill, indicated the suitability of the landfill-gas-to-energy conversion equipment to operate on a

J. L. Preston; J. C. Trocciola

1998-01-01

117

First-order kinetic gas generation model parameters for wet landfills  

Microsoft Academic Search

Landfill gas collection data from wet landfill cells were analyzed and first-order gas generation model parameters were estimated for the US EPA landfill gas emissions model (LandGEM). Parameters were determined through statistical comparison of predicted and actual gas collection. The US EPA LandGEM model appeared to fit the data well, provided it is preceded by a lag phase, which on

Ayman A. Faour; Debra R. Reinhart; Huaxin You

2007-01-01

118

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

SciTech Connect

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.

Thorneloe, S.A.

1993-01-01

119

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

PubMed

A field scale trial was undertaken at a landfill site in Sydney, Australia (2004-2008), to investigate passive drainage and biofiltration of landfill gas as a means of managing landfill gas emissions from low to moderate gas generation landfill sites. The objective of the trial was to evaluate the effectiveness of a passive landfill gas drainage and biofiltration system at treating landfill gas under field conditions, and to identify and evaluate the factors that affect the behaviour and performance of the system. The trial results showed that passively aerated biofilters operating in a temperate climate can effectively oxidise methane in landfill gas, and demonstrated that maximum methane oxidation efficiencies greater than 90% and average oxidation efficiencies greater than 50% were achieved over the 4 years of operation. The trial results also showed that landfill gas loading was the primary factor that determined the behaviour and performance of the passively aerated biofilters. The landfill gas loading rate was found to control the diffusion of atmospheric oxygen into the biofilter media, limiting the microbial methane oxidation process. The temperature and moisture conditions within the biofilter were found to be affected by local climatic conditions and were also found to affect the behaviour and performance of the biofilter, but to a lesser degree than the landfill gas loading. PMID:21147522

Dever, Stuart A; Swarbrick, Gareth E; Stuetz, Richard M

2010-12-13

120

Bioenergy recovery from landfill gas: A case study in China  

Microsoft Academic Search

Landfill gas (LFG) utilization which means a synergy between environmental protection and bioenergy recovery was investigated\\u000a in this study. Pressure swing adsorption technology was used in LFG purification, and laboratory experiment, pilot-scale test,\\u000a and on-site demonstration were carried out in Shenzhen, China. In the laboratory experiment, A-type carbon molecular sieve\\u000a was selected as the adsorbent by comparison of several other

Wei Wang; Yuxiang Luo; Zhou Deng

2009-01-01

121

Numerical Early Warning Model Research of Landfill Gas Permeation and Diffusion Considering Flow-Temperature Coupling  

Microsoft Academic Search

Based on seepage mechanics in porous medium gas and heat transfer theory, numerical early warning model is established, which is on quantitative description of migration and release of landfill gas and penetration and diffusion of energy, and dynamic migration of landfill gas is also analyzed quantitatively. The results show that the gas pressure improved as the depth increased, and internal

Xue Qiang; Feng Xia-ting; Ma Shi-jin; Zhou Xiao-jun

2009-01-01

122

Solid waste characteristics and their relationship to gas production in tropical landfill  

Microsoft Academic Search

Solid waste characteristics and landfill gas emission rate in tropical landfill was investigated in this study. The experiment\\u000a was conducted at a pilot landfill cell in Thailand where fresh and two-year-old wastes in the cell were characterized at various\\u000a depths of 1.5, 3, 4.5 and 6 m. Incoming solid wastes to the landfill were mainly composed of plastic and foam (24.05%).

C. Chiemchaisri; W. Chiemchaisri; Sunil Kumar; J. P. A. Hettiaratchi

2007-01-01

123

Landfill gas recovery: should your community consider it  

SciTech Connect

Communities which decide to recover, process, and sell landfill gas as a local, low-cost energy source will also derive significant environmental benefits as well. Getty Synthetic Fuels has been a pioneer in the field of methane gas recovery technology. On the basis of this experience, Getty suggests how communities can benefit in the areas of environment, reduction of odor and hydrocarbon emissions, developing a local energy source, safety, aesthetics, revenue, local employment, and regulatory assistance through services provided by a developer. Many communities may find that the environmental benefits outweigh energy considerations.

Shuput, T.A.

1985-08-01

124

Environmental assessment and sustainable management options of leachate and landfill gas treatment in Estonian municipal waste landfills  

Microsoft Academic Search

Purpose – The purpose of this paper is to compare various landfill gas (LFG) and leachate treatment technologies in a life-cycle perspective. Design\\/methodology\\/approach – Since a landfill causes emissions for a very long-time period, life-cycle-based environmental assessment was carried out to compare different technological options for sustainable leachate treatment and LFG collection and utilization. WAMPS, the life-cycle assessment (LCA) model

Viktoria Voronova; Harri Moora; Enn Loigu

2011-01-01

125

Treatment and utilization of landfill gas. Mountain View Project Feasibility Study  

Microsoft Academic Search

The production, treating, transportation, and utilization of landfill gas are discussed in this report. The economics of these steps are also covered. The analysis is performed from the perspective of the Pacific Gas and Electric Company, one of the partners in the Mountain View Landfill Gas Recovery Demonstration Project, scheduled to be operating by early 1977. The U.S. Environmental Protection

Blanchet

1977-01-01

126

Landfill Gas Conversion to Contaminant-Free Methane-Carbon Dioxide Reformer Feedstock for Methane Synthesis.  

National Technical Information Service (NTIS)

Landfill gas, a mixture of methane and carbon dioxide generated by the anaerobic decomposition of municipal solid waste, is a natural resource in many ways similar to low quality natural gas. A major barrier to widespread utilization of landfill gas (LFG)...

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

1997-01-01

127

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

PubMed

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. PMID:20124321

Haibin Han; Jisheng Long; Shude Li; Guangren Qian

2010-02-02

128

Energetic and Methane Emission Reduction Potentials from an Unsanitary Landfill  

Microsoft Academic Search

Al Akeeder is the largest landfill site in northern Jordan. The site operation started in 1981 by open dumping and combusting then converted to unsanitary landfilling (without biogas and leachate management). The objective of this article is to estimate the energy and methane emission reduction potentials of the landfill. The amount and composition of the landfill gas were estimated by

H. A. Abu Qdais; A. M. Maqableh; L. M. Al Nawayseh; N. M. Al Jamal

2011-01-01

129

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

PubMed

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. PMID:12201689

Christophersen, M; Kjeldsen, P

2001-12-01

130

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

PubMed

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. PMID:11721997

Christophersen, M; Kjeldsen, P

2001-04-01

131

Development of the utilization of combustible gas produced in existing sanitary landfills: Effects of corrosion at the Mountain View, California landfill gas-recovery plant  

NASA Astrophysics Data System (ADS)

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.

1982-10-01

132

Technical and Nontechnical Issues Regarding Landfill Gas to Energy: What Is Their Impact on the U.S. Landfill Gas Industry.  

National Technical Information Service (NTIS)

The paper summarizes ongoing EPA research on landfill gas (LFG) utilization. Research was conducted to identify technical issues and solutions through interviews conducted with industry experts in the U.S., Europe, and Australia. The paper provides summar...

S. A. Thorneloe J. G. Pacey M. Doorn

1995-01-01

133

Feasibility of direct on-site conversion of landfill gas to electrical energy at Scholl Canyon landfill, California  

NASA Astrophysics Data System (ADS)

The technical and economic feasibility of direct onsite conversion of landfill gas into electrical energy for distribution through the municipal company's distribution grid is described. The various approaches are evaluated. Each system looked at the preliminary collection system layout, type of processing, and conversion equipment required, conversion efficiencies, total system costs, total energy output per input landfill gas, and overall economic comparisons between alternatives. This led to the selection of the internal combustion engine. The legal constraints on interdepartmental transfers of money and resources, city procedures for coordination between the public works department and public services, procedures for facility operation, and an environmental assessment of each alternative were investigated.

Lofy, R. J.

1981-06-01

134

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...

135

Spatial variability of soil gas concentration and methane oxidation capacity in landfill covers.  

PubMed

In order to devise design criteria for biocovers intended to enhance the microbial oxidation of landfill methane it is critical to understand the factors influencing gas migration and methane oxidation in landfill cover soils. On an old municipal solid waste landfill in north-western Germany soil gas concentrations (10, 40, 90 cm depth), topsoil methane oxidation capacity and soil properties were surveyed at 40 locations along a 16 m grid. As soil properties determine gas flow patterns it was hypothesized that the variability in soil gas composition and the subsequent methanotrophic activity would correspond to the variability of soil properties. Methanotrophic activity was found to be subject to high spatial variability, with values ranging between 0.17 and 9.80 g CH(4)m(-2)h(-1)(.) Considering the current gas production rate of 0.03 g CH(4)m(-2)h(-1), the oxidation capacity at all sampled locations clearly exceeded the flux to the cover, and can be regarded as an effective instrument for mitigating methane fluxes. The methane concentration in the cover showed a high spatial heterogeneity with values between 0.01 and 0.32 vol.% (10 cm depth), 22.52 vol.% (40 cm), and 36.85 vol.% (90 cm). The exposure to methane raised the oxidation capacity, suggested by a statistical correlation to an increase in methane concentration at 90 cm depth. Methane oxidation capacity was further affected by the methanotroph bacteria pH optimum and nutrient availability, and increased with decreasing pH towards neutrality, and increased with soluble ion concentration). Soil methane and carbon dioxide concentration increased with lower flow resistance of the cover, as represented by the soil properties of a reduced bulk density, increase in air capacity and in relative ground level. PMID:20943363

Röwer, Inga Ute; Geck, Christoph; Gebert, Julia; Pfeiffer, Eva-Maria

2010-10-12

136

Measured gas emissions from four landfills in south africa and some implications for landfill design and methane recovery in semi-arid climates.  

PubMed

The magnitude of annual global emissions of methane from municipal solid waste landfills without landfill gas control systems implies that these landfills are significant contributors to the atmospheric load of greenhouse gases. There have been a number of field studies undertaken internationally to measure actual fluxes of methane and carbon dioxide from landfills, with a view to corroborating modelled predictions of the contribution of landfills to the global greenhouse gas budget. The vast majority of these studies have been undertaken in more temperate climates and in developed countries. This paper reports a study of landfill gas emissions from four large landfills located in the semi-arid interior of South Africa. A static accumulation chamber was used and measurements were made at each site over a period of two to three days. The results were analysed by three different methods, all of them leading to the same general conclusion that landfill gas emission rates were lower than expected. A common conclusion based on results from all four sites was that capping of landfills in semi-arid climates with low permeability covers would probably significantly retard the already low rate of waste degradation and thus gas generation. While this may be regarded as advantageous in the short term, it cannot be relied upon in perpetuity as clayey landfill covers will inevitably desiccate and crack in a semiarid environment. In addition, reasonable after-care periods for such landfills are likely to extend well beyond the currently stipulated 30-year period, and efforts to encourage energy recovery from landfills may be hampered because gas generation rates decrease as the waste dries out under conditions of minimal recharge from precipitation. A landfill cover that allows small amounts of percolation of rainfall into the waste may therefore in fact be beneficial in semiarid climates, although care would need to be taken to carefully regulate this infiltration. PMID:15666447

Fourie, A B; Morris, J W F

2004-12-01

137

Evaluation Test on a Landfill Gas-Fired Flare at the BKK Landfill Facility, West Covina, CA.  

National Technical Information Service (NTIS)

A cooperative test program was conducted from March 3 through March 7, 1986, by Air Resources Board (ARB) and South Coast Air Quality Management District (SCAQMD) staff to evaluate the gaseous constituents from untreated landfill gas used to fuel a ground...

1986-01-01

138

Effect of quantity and composition of waste on the prediction of annual methane potential from landfills.  

PubMed

A study was conducted to investigate the effect of waste composition change on the methane production in landfills. An empirical equation for the methane potential of the mixed waste is derived based on the methane potential values of individual waste components and the compositional ratio of waste components. A correction factor was introduced in the equation and was determined from the BMP and lysimeter tests. The equation and LandGEM were applied for a full size landfill and the annual methane potential was estimated. Results showed that the changes in quantity of waste affected the annual methane potential from the landfill more than the changes of waste composition. PMID:22300637

Cho, Han Sang; Moon, Hee Sun; Kim, Jae Young

2012-01-15

139

Landfill Gas and Its Influence on Global Climate Change.  

National Technical Information Service (NTIS)

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 devel...

S. A. Thorneloe

1993-01-01

140

Determination of first-order landfill gas modeling parameters and uncertainties.  

PubMed

Using first-order kinetic empirical models to estimate landfill gas (LFG) generation and collection rates is well recognized in the literature. The uncertainty in the estimated LFG generation rates is a major challenge in evaluating performance of LFG collection and LFG to energy facilities. In this investigation, four methods for quantifying first-order LFG generation model parameters, methane generation potential, L(0), and methane generation rate constant, k, were evaluated. It was found that the model is insensitive to the approach taken in quantifying the parameters. However, considering the recognition of using the model in the literature, the optimum method to estimate L(0) and k is to determine L(0) using disposed municipal solid waste composition and laboratory component specific methane potential values. The k value can be selected by model fitting and regression using the first-order model if LFG collection data are available. When such data are not available, k can be selected from technical literature, based on site conditions. For five Florida case-study landfills L(0) varied from 56 to 77 m(3) Mg(-1), and k varied from 0.04 to 0.13 yr(-1) for the traditional landfills and was 0.10 yr(-1) for the wet cell. Model predictions of LFG collection rates were on average lower than actual collection. The uncertainty (coefficient of variation) in modeled LFG generation rates varied from ±11% to ±17% while landfills were open, ±9% to ±18% at the end of waste placement, and ±16% to ±203% 50 years after waste placement ended. PMID:22000722

Amini, Hamid R; Reinhart, Debra R; Mackie, Kevin R

2011-10-14

141

Impact of the Resource Conservation and Recovery Act on Landfill Gas Utilization.  

National Technical Information Service (NTIS)

A survey was made to determine the number of landfills and their sizes that would be affected by the gas criteria of the RCRA Open Dump Inventory project. The cost-effectiveness of active systems and hybrid systems were also determined for landfills repre...

1983-01-01

142

A STRATEGY FOR THE DEVELOPMENT OF LANDFILL GAS TECHNOLOGY IN INDIA  

Microsoft Academic Search

Landfilling is commonly being developed as a renewable source of energy through the systematic recovery and utilization of biogas generated during anaerobic decomposition of municipal solid wastes. In India there is good scope for the development of landfill gas technology as municipal solid waste contains a high proportion of degradable organic matter. Biogas generation from various sources is also seen

A. V. Shekdar

1997-01-01

143

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

Microsoft Academic Search

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

K. David Newell; Timothy R. Carr

2007-01-01

144

Landfill disposal of limestone dual-alkali flue-gas-desulfurization waste. Final report  

Microsoft Academic Search

A landfill disposal test program was undertaken to demonstrate the addition of fly ash and lime to calcium sulfite-sulfate flue gas desulfurization (FGD) wastes and to establish design and operating guidelines for an environmentally acceptable waste disposal system. A lined, diked landfill disposal site was partially filled with waste mixtures of FGD filter cake, fly ash, and lime. Field samples

L. K. Fox; E. D. Gibson; J. F. Pierson; D. M. Brown

1982-01-01

145

Recovery and utilization of methane gas from a sanitary landfill: City of Industry, California  

Microsoft Academic Search

The design and installation of a system to recover and utilize methane gas produced in a completed sanitary landfill is described. A 160-acre landfill, completed in 1967, is located within a larger 500-acre parcel owned and currently under development by the City of Industry, California. The overall development includes two 18-hole championship golf courses, golf clubhouse and service facilities, an

R. P. Stearns; T. D. Wright; M. Brecher

2008-01-01

146

Carbon dioxide removal and capture for landfill gas up-grading  

Microsoft Academic Search

Within the frame of an EC financially supported project - LIFE05 ENV\\/IT\\/000874 GHERL (Greenhouse Effect Reduction from Landfill)–a pilot plant was set up in order to demonstrate the feasibility of applying chemical absorption to remove carbon dioxide from landfill gas. After proper upgrading - basically removal of carbon dioxide, hydrogen sulphide, ammonia and other trace gas compound–the gas might be

Lidia Lombardia; Andrea Corti; Ennio Carnevale; Renato Baciocchi; Daniela Zingaretti

2011-01-01

147

Work Plan for Development of a Data Base on Potential Landfill-Gas Utilization Sites in the United States.  

National Technical Information Service (NTIS)

In an attempt to determine the effects of the criteria established by the Resource Conservation and Recovery Act (RCRA) Section 4004's Open Dump Inventory (ODI) upon the establishment of landfill gas utilization projects, a national survey of landfills wa...

1982-01-01

148

Degradation of starch-plastic composites in a municipal solid waste landfill  

Microsoft Academic Search

The rate and extent of deterioration of starch-plastic composites were determined over a 2-year period for samples buried in a municipal solid waste landfill. The deterioration of the starch-plastic composites following exposure was determined by measuring changes in tensile properties, weight loss, and starch content of samples retrieved from the landfill. Elongation decreases of 92 and 44% were measured for

Vincent T. Breslin

1993-01-01

149

Recovery, processing, and utilization of gas from sanitary landfills. Final report mar 77-sep 78  

Microsoft Academic Search

The report is organized into seven sections. Following the introduction and conclusions and recommendations, are sections describing: the three-component gas generation phenomenon; analysis and comparison of alternative gas utilizations including the processes necessary to prepare the gas for use; an evaluation of various landfill design approaches and operations techniques that show promise for enhancing gas generation, recovery efficiency and quality;

R. K. Ham; K. K. Hekimian; S. L. Katten; W. J. Lockman; R. J. Lofy

1979-01-01

150

Biostabilization of landfill waste  

SciTech Connect

In November 1991, the city of Albany, N.Y., together with the principals of Landfill Service Corp. (Apalachin, N.Y.), proposed to demonstrate the successful practice of biostabilized solid waste placement in the newly constructed, double-composite-lined Interim Landfill located in the city of Albany. The small landfill covers just 12 acres and is immediately adjacent to residential neighbors. The benefits of this biostabilization practice include a dramatic improvement in the orderliness of waste placement, with significant reduction of windblown dust and litter. The process also reduces the presence of typical landfill vectors such as flies, crows, seagulls, and rodents. The physically and biologically uniform character of the stabilized waste mass can result in more uniform future landfill settlement and gas production properties. This can allow for more accurate prediction of post-closure conditions and reduction or elimination of remedial costs attendant to post-closure gross differential settlement.

Hansen, D.L. [Landfill Service Corp., Apalachin, NY (United States)

1995-06-01

151

Attenuation of Methane and Volatile Organic Compounds in Landfill Soil Covers  

Microsoft Academic Search

trace components originate from hazardous materials deposited in the landfill or from biological or chemical The potential for natural attenuation of volatile organic compounds degradation of materials disposed of in the landfill. Due (VOCs) in landfill covers was investigated in soil microcosms incu- bated with methane and air, simulating the gas composition in landfill to pressure and concentration gradients, the

Charlotte Scheutz; Hans Mosbæk; Peter Kjeldsen

2004-01-01

152

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

SciTech Connect

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.

Jung, Yoojin; Han, Byunghyun; Mostafid, M. Erfan; Chiu, Pei [Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716 (United States); Yazdani, Ramin [Yolo County Planning and Public Works Department, Division of Integrated Waste Management, Yolo County, 44090 County Rd. 28H, Woodland, CA 95776 (United States); Imhoff, Paul T., E-mail: imhoff@udel.edu [Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716 (United States)

2012-02-15

153

Controlling greenhouse gas emissions through landfill in situ aeration  

Microsoft Academic Search

Landfills and old waste deposits are some of the major anthropogenic sources of methane (CH4) emissions worldwide. Despite the fact that during the last 15 years the amount of carbon dioxide equivalent (CO2-eq.) emitted from German landfills was reduced by approximately two thirds, estimates show that currently more than 10Mtonnes are still being emitted annually. As a case study, the

M. Ritzkowski; R. Stegmann

2007-01-01

154

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

SciTech Connect

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.

El-Fadel, Mutasem, E-mail: mfadel@aub.edu.lb [Department of Civil and Environmental Engineering, American University of Beirut (Lebanon); Abi-Esber, Layale; Salhab, Samer [Department of Civil and Environmental Engineering, American University of Beirut (Lebanon)

2012-11-15

155

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

PubMed

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. PMID:16245803

Jaramillo, Paulina; Matthews, H Scott

2005-10-01

156

Landfill gas-fired power plant pays cost of operating landfill  

Microsoft Academic Search

This paper reports on recovery of energy from refuse that has become increasingly attractive in the past decade. The continuing urbanization of our society has created major challenges in the disposal of our waste products. Because of public concern over the potential presence of toxins, and for other environmental reasons, management and regulation of active and inactive landfills have become

Wallace

1991-01-01

157

Methane mass balance at three landfill sites: what is the efficiency of capture by gas collection systems?  

PubMed

Many developed countries have targeted landfill methane recovery among greenhouse gas mitigation strategies, since methane is the second most important greenhouse gas after carbon dioxide. Major questions remain with respect to actual methane production rates in field settings and the relative mass of methane that is recovered, emitted, oxidized by methanotrophic bacteria, laterally migrated, or temporarily stored within the landfill volume. This paper presents the results of extensive field campaigns at three landfill sites to elucidate the total methane balance and provide field measurements to quantify these pathways. We assessed the overall methane mass balance in field cells with a variety of designs, cover materials, and gas management strategies. Sites included different cell configurations, including temporary clay cover, final clay cover, geosynthetic clay liners, and geomembrane composite covers, and cells with and without gas collection systems. Methane emission rates ranged from -2.2 to >10,000 mg CH(4) m(-2) d(-1). Total methane oxidation rates ranged from 4% to 50% of the methane flux through the cover at sites with positive emissions. Oxidation of atmospheric methane was occurring in vegetated soils above a geomembrane. The results of these studies were used as the basis for guidelines by the French environment agency (ADEME) for default values for percent recovery: 35% for an operating cell with an active landfill gas (LFG) recovery system, 65% for a temporary covered cell with an active LFG recovery system, 85% for a cell with clay final cover and active LFG recovery, and 90% for a cell with a geomembrane final cover and active LFG recovery. PMID:16198554

Spokas, K; Bogner, J; Chanton, J P; Morcet, M; Aran, C; Graff, C; Golvan, Y Moreau-Le; Hebe, I

2005-09-29

158

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 ...

159

Evaluation of landfill gas production and emissions in a MSW large-scale Experimental Cell in Brazil  

Microsoft Academic Search

Landfill gas (LFG) emissions from municipal solid waste (MSW) landfills are an important environmental concern in Brazil due to the existence of several uncontrolled disposal sites. A program of laboratory and field tests was conducted to investigate gas generation in and emission from an Experimental Cell with a 36,659-ton capacity in Recife\\/PE – Brazil. This investigation involved waste characterisation, gas

Felipe Jucá Maciel; José Fernando Thomé Jucá

2011-01-01

160

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

Microsoft Academic Search

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 CH4 oxidation. Different materials were tested in actively aerated lab-scale bio-filter systems with a volume of 0.167m3. The required

R. Haubrichs; R. Widmann

2006-01-01

161

Landfill gas utilization: Database of North American projects. Report for July 1993March 1994  

Microsoft Academic Search

Data landfill-gas (LFG)-to-energy projects have been reported for U.S. landfills and to a lesser extent on Canadian projects. The paper describes the LFG-to-energy industry, providing data on the types of projects in North America, the current energy output of these projects,and the trends impacting this industry. Also provided in the paper is a list of the projects in North America

S. A. Thorneloe; J. G. Pacey

1994-01-01

162

Landfill gas: resource evaluation and development. Final report, August-July, 1985  

Microsoft Academic Search

The study developed a document that will assist utilities, municipalities, and other interested parties in evaluating the potential for using landfill-gas (LFG) resources. The LFG workbook describes the state-of-the-art methodology for energy recovery from landfill sites, and the techniques used to evaluate the feasibility of a potential project. The document provides the reader with background in a number of areas.

R. E. Zimmerman; J. J. Walsh; M. Wilkey

1985-01-01

163

Fatal Flaws in Measuring Landfill Gas Generation Rates by Empirical Well Testing  

Microsoft Academic Search

Well testing procedures, such as the Tier 3 methodology specified in the U.S. Code of Federal Regulations (CFR) Subtitle D, are commonly used for directly estimating landfill gas (LFG) emissions at municipal solid waste (MSW) landfills. Similar procedures are also used to estimate LFG generation rates for the design of LFG-to-energy projects. These methodologies assume that the LFG generation rate

Gary R. Walter

2003-01-01

164

Determination of siloxanes and VOC in landfill gas and sewage gas by canister sampling and GC-MS\\/AES analysis  

Microsoft Academic Search

Biogases such as landfill gas and sewage gas undergo a combustion process which is generating electric energy. Since several trace compounds such as siloxanes (also halogenated and sulfur compounds) are known to cause severe problems to these gas combustion engines, they are of particular interest. In this work, a new technique for sampling, identification, and quantification of siloxanes and volatile

Martin Schweigkofler; Reinhard Niessner

1999-01-01

165

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

SciTech Connect

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.

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

2000-10-20

166

Landfill gas cleanup for carbonate fuel cell power generation. Final report  

Microsoft Academic Search

To utilize landfill gas for power generation using carbonate fuel cells, the LFG must be cleaned up to remove sulfur and chlorine compounds. This not only benefits the operation of the fuel cell, but also benefits the environment by preventing the emission of these contaminants to the atmosphere. Commercial technologies for gas processing are generally economical in relatively large sizes

G. Steinfeld; R. Sanderson

1998-01-01

167

Landfill gas and leachate monitoring: Helena, Montana - a technical assistance panels program report. Final report  

Microsoft Academic Search

Leachate contamination of ground water and methane gas production are potential problems associated with solid wastes deposited in landfills. Expanding urban areas may utilize former sites for residential building sites, schools, and parks. This report presents an example of a method which can be used to design a permanent methane gas and leachate monitoring program from a relatively inexpensive preliminary

R. Baker; M. Jewett; D. Jubenville; D. Kuntz; B. Lokey

1981-01-01

168

Fundamental and environmental aspects of landfill gas utilization for power generation  

Microsoft Academic Search

Landfill gas (LFG) results from the biological decomposition of municipal waste and consists of mostly equal amounts of CO2 and CH4, as well as trace amounts of a variety of other organic compounds. Upon removal of most of the trace organic compounds, LFG can be used as fuel in internal combustion engines and gas turbines for generation of heat and

W. Qin; F. N. Egolfopoulos; T. T. Tsotsis

2001-01-01

169

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. his phase consisted primarily of the construction and testing of a Gas Pretreatment Unit (GPU) whose function is to remove those impur...

170

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...

171

Development of the utilization of combustible gas produced in existing sanitary landfills: evaluation of the use of carbon dioxide produced in sanitary landfills  

Microsoft Academic Search

This report is a survey of the potential markets for carbon dioxide derived from the purification of landfill gas into 1) a methane rich stream which can be used as a high Btu (950\\/SCF) fuel gas, and (2) a carbon dioxide-rich stream. Interviews with individuals in the COâ industry have revealed the potential markets for COâ, gas purities required for

E. Ashare; A. C. Sharon; L. R. Moschini

1981-01-01

172

Development of the utilization of combustible gas produced in existing sanitary landfills: evaluation of the use of carbon dioxide produced in sanitary landfills  

Microsoft Academic Search

The potential markets are surveyed for carbon dioxide derived from the purification of landfill gas into 1) a methane rich stream which can be used as a high Btu (950\\/SCF) fuel gas, and 2) a carbon dioxide-rich stream. Interviews with individuals in the COâ industry have revealed the potential markets for COâ, gas purities required for different applications, and wholesale

E. Ashare; A. C. Sharon; L. R. Moschini

1982-01-01

173

Landfill gas energy utilization: Technical and non-technical considerations. Report for September 1992March 1994  

Microsoft Academic Search

The paper discusses technical issues associated with the use of landfill gas (LFG) compared with natural gas--which is the primary fuel used for energy conversion equipment such as internal combustion engines, gas turbines, and fuel cells. LFG is a medium-heating-value fuel containing trace constituents that require gas pretreatment and energy equipment modifications to operate successfully. There are more than 100

J. G. Pacey; M. R. J. Doorn; S. A. Thorneloe

1994-01-01

174

Solid waste characteristics and their relationship to gas production in tropical landfill.  

PubMed

Solid waste characteristics and landfill gas emission rate in tropical landfill was investigated in this study. The experiment was conducted at a pilot landfill cell in Thailand where fresh and two-year-old wastes in the cell were characterized at various depths of 1.5, 3, 4.5 and 6 m. Incoming solid wastes to the landfill were mainly composed of plastic and foam (24.05%). Other major components were food wastes (16.8%) and paper (13.3%). The determination of material components in disposed wastes has shown that the major identifiable components in the wastes were plastic and foam which are resistant to biodegradation. The density of solid waste increased along the depth of the landfill from 240 kg m(-3) at the top to 1,260 kg m(-3) at the bottom. Reduction of volatile solids content in waste samples along the depth of landfill suggests that biodegradation of solid waste has taken place to a greater extent at the bottom of the landfill. Gas production rates obtained from anaerobic batch experiment were in agreement with field measurements showing that the rates increased along the depth of the landfill cell. They were found in range between 0.05 and 0.89 l kg(-1) volatile solids day(-1). Average emission rate of methane through the final cover soil layer was estimated as 23.95 g(-2)day(-1) and 1.17 g(-2)day(-1) during the dry and rainy seasons, respectively. PMID:17458513

Chiemchaisri, C; Chiemchaisri, W; Kumar, Sunil; Hettiaratchi, J P A

2007-04-26

175

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

PubMed

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. PMID:20685441

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

2010-04-09

176

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...

177

Methane mass balance at three landfill sites: What is the efficiency of capture by gas collection systems?  

Microsoft Academic Search

Many developed countries have targeted landfill methane recovery among greenhouse gas mitigation strategies, since methane is the second most important greenhouse gas after carbon dioxide. Major questions remain with respect to actual methane production rates in field settings and the relative mass of methane that is recovered, emitted, oxidized by methanotrophic bacteria, laterally migrated, or temporarily stored within the landfill

K.. Spokas; J. Bogner; J. P. Chanton; M. Morcet; C. Aran; C. Graff; Y. Moreau-Le Golvan; I. Hebe

2006-01-01

178

Landfill gas with hydrogen addition – A fuel for SI engines  

Microsoft Academic Search

The recent quest to replace fossil fuels with renewable and sustainable energy sources has increased interest on utilization of landfill and bio gases. It is further augmented due to environment concerns and global warming caused by burning of conventional fossil fuels, energy security concerns and high cost of crude oil, and renewable nature of these gases. The main portion of

S. O. Bade Shrestha; G. Narayanan

2008-01-01

179

Landfill Gas Emissions Model, version 2.0., user`s manual. Final report, September 1993--September 1997  

SciTech Connect

Landfill Gas Emissions Model (LandGEM) estimates air pollutant emissions from municipal solid waste (MSW) landfills. The model can be used to estimate emission rates for methane, carbon dioxide, nonmethane organic compounds, and individual air pollutants from landfills. It can also be used by landfill owners and operators to determine if a landfill is subject to the control requirements of the federal New Source Performance Standard (NSPS) for new MSW landfills or the emission guidelines for existing MSW landfills. The model is based on a first order decay equation and can be run using site-specific data are available, using default values: one set based on the requirements of the NSPS and emission guidelines, and the other based on emission factors in EPA`s Compilation of Air Pollutant Emission Factors, AP-42.

Pelt, R.; Bass, R.; Heaton, R.; White, C.; Blackard, A.

1998-05-01

180

Optimal waste decomposition -- Landfill as treatment process  

SciTech Connect

Landfills can be regarded as uncontrolled anaerobic digestors. An increasingly popular landfill management technique involves moisture addition and/or leachate recycle which can enhance stabilization, increase gas production, and improve leachate quality. Leachate recycle operations have not been guided by theory. In this paper, the optimal control theory is applied to managing waste decomposition in landfills through leachate recycle. The technique minimizes net present value cost of landfill postclosure operations while satisfying landfill liner safety constraints. The optimal control method specifies leachate recycle rates through the landfill lifetime and the optimal leachate collection and distribution system capacities. The approach is applied to a simplified model of waste decomposition in a typical excavated cell landfill with composite liner.

Anex, R.P. [Univ. of Oklahoma, Norman, OK (United States)

1996-11-01

181

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

Microsoft Academic Search

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

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

1998-01-01

182

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

NASA Astrophysics Data System (ADS)

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.

2000-05-01

183

Comparison study of ammonia and COD adsorption on zeolite, activated carbon and composite materials in landfill leachate treatment  

Microsoft Academic Search

Chemical oxygen demand (COD) and ammoniacal nitrogen have always been the crucially problematic parameters in landfill leachate treatment. This study was conducted to investigate the adsorption properties of ammoniacal nitrogen and COD in semi-aerobic leachate from the Pulau Burung landfill site on zeolite, activated carbon and a new composite media in terms of adsorption isotherm and kinetic. The results show

Azhar Abdul Halim; Hamidi Abdul Aziz; Megat Azmi Megat Johari; Kamar Shah Ariffin

2010-01-01

184

Methane oxidation activity and bacterial community composition in a simulated landfill cover soil is influenced by the growth of Chenopodium album L  

Microsoft Academic Search

Oxygen availability in landfill cover soil is a major limitation to the growth and activity of methanotrophs as methane oxidation is an aerobic microbial process. Plants tolerant to high concentrations of landfill gas (LFG) may play an important role in improving methane oxidation within landfill cover soil and reducing emission of methane, a greenhouse gas, from it. In this study,

Yunlong Wang; Weixiang Wu; Ying Ding; Wei Liu; Anton Perera; Yingxu Chen; Medha Devare

2008-01-01

185

Trigeneration: A new way for landfill gas utilization and its feasibility in Hong Kong  

Microsoft Academic Search

Application of landfill gas (LFG) means a synergy between environmental protection and energy production. This paper presents a review of the status of LFG application. To more efficiently utilize the LFG in Hong Kong, a trigeneration scheme is proposed as a new way of LFG utilization. The feasibility of LFG trigeneration in Hong Kong is evaluated from the views of

Xiaoli Hao; Hongxing Yang; Guoqiang Zhang

2008-01-01

186

Emerging technologies for the management and utilization of landfill gas. Final report, August 1994August 1997  

Microsoft Academic Search

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 utilization of methane (CH4) and carbon dioxide (CO2) from LFG. The emerging technologies that are considered to be Tier

S. Roe; J. Reisman; R. Strait; M. Doorn

1998-01-01

187

Landfill gas as an energy resource: past, present and indications for the future  

Microsoft Academic Search

Landfill gas has proven to be a cost-effective, economic energy resource. To date utilization schemes have been recorded in 20 countries worldwide, producing a total resource of over 2 million tonnes of coal equivalent per annum (mtcepa). In the UK savings are currently estimated to be in the region of 120,000 tcepa. This paper discusses the trends which have resulted

P. S. Lawson

1989-01-01

188

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...

189

Database of Landfill Gas to Energy Projects in the United States.  

National Technical Information Service (NTIS)

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...

S. Thorneloe A. Roqueta J. Pacey C. Bottero

1999-01-01

190

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

SciTech Connect

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.

Reichenauer, Thomas G., E-mail: thomas.reichenauer@ait.ac.at [Health and Environment Department, Environmental Resources and Technologies, AIT - Austrian Institute of Technology GmbH, 2444 Seibersdorf (Austria); Watzinger, Andrea; Riesing, Johann [Health and Environment Department, Environmental Resources and Technologies, AIT - Austrian Institute of Technology GmbH, 2444 Seibersdorf (Austria); Gerzabek, Martin H. [Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Applied Life Sciences, Peter Jordan-Strasse 82, 1190 Vienna (Austria)

2011-05-15

191

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...

192

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...

193

Nation's first fuel cell power plant powered by processed landfill gas  

Microsoft Academic Search

Southern California Edison Company (Edison) and the Los Angeles Department of Water and Power (LADWP) installed, and are operating, a 40 kw phosphoric acid fuel cell utilizing processed landfill gas at a hotel and convention complex in the City of Industry, California. This field test aims to establish important electric utility operating criteria of two separate, promising technologies linked together

J. D. Leeper; W. W. Engels

1986-01-01

194

Abatement of synthetic landfill gas including limonene by biotrickling filter and membrane biofiltration  

Microsoft Academic Search

In this study, a single silicone rubber membrane biofilter was compared to a lava rock biotrickling filter to examine the aerobic biofiltration of synthetic landfill gas including odorous limonene. The membrane bioreactor and biotrickling filter showed, respectively, maximum elimination capacities of 17 g m h and 31.3 g m h for limonene and removal efficiencies of 11 % and 18

Fatih Hosoglu; Mark W. Fitch

2012-01-01

195

Landfill Gas Energy Utilization Experience: Discussion of Technical and Non-Technical Issues, Solutions, and Trends.  

National Technical Information Service (NTIS)

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...

D. Augenstein J. Pacey M. Doorn

1995-01-01

196

Landfill gas utilization: Database of North American projects. Report for July 1993-March 1994  

SciTech Connect

Data landfill-gas (LFG)-to-energy projects have been reported for U.S. landfills and to a lesser extent on Canadian projects. The paper describes the LFG-to-energy industry, providing data on the types of projects in North America, the current energy output of these projects,and the trends impacting this industry. Also provided in the paper is a list of the projects in North America and summary statistics of the database that is being collected through the cooperation of industry.

Thorneloe, S.A.; Pacey, J.G.

1994-01-01

197

Soil-gas survey at the solid waste landfill - Final Report  

SciTech Connect

A soil-gas survey to determine the lateral distribution of chlorinated hydrocarbon solvents in the vadose zone, and possibly ground water, was conducted at the Hanford Site Solid Waste Landfill. For a 2-year period, three trenches just inside the western perimeter of the landfill had received liquid discharges of both sewage and washwater, which contained solvents. Ground-water monitoring wells, installed a few months after liquid discharge had been discontinued, indicated very low levels (less than 10 ppb) of solvents exist in the ground water downgradient from the disposal trenches. 13 refs., 7 figs., 1 tab.

Evans, J.C.; Fruland, R.M.; Glover, D.W.; Veverka, C.

1989-12-01

198

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

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.

Cook, W.J.; Brown, W.R.; Siwajek, L. [Acrion Technologies, Inc., Cleveland, OH (United States); Sanders, W.I. [Power Management Corp., Bellevue, WA (United States); Botgros, I. [Petrodesign, SA, Bucharest (Romania)

1998-09-01

199

Recovery and Utilization of Gas from Sanitary Landfills. Evaluation of the Research Program of the Danish Minsitry of Energy.  

National Technical Information Service (NTIS)

A summary and evaluation are presented of the research, supported by the Danish Ministry of Energy, on recovery and utilization of gas from sanitary landfills. Also examples of full scale plants at some landfills of different size are presented. The resea...

1985-01-01

200

Characterization of trace constituents in landfill gas and a comparison of sites in Asia  

Microsoft Academic Search

Because landfill gas (LFG) contains an abundance of methane, the utilization of LFG as a renewable energy source is becoming\\u000a popular in many countries. LFG, however, contains various trace constituents, some of which may pose problems during utilization.\\u000a For example, siloxanes and halogenated volatile organic compounds (VOCs) can cause difficulties when present in the fuel of\\u000a gas engines. In addition,

Yuya Takuwa; Tadao Matsumoto; Kazuyuki Oshita; Masaki Takaoka; Shinsuke Morisawa; Nobuo Takeda

2009-01-01

201

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

Microsoft Academic Search

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

M. Mintz; J. Han; M. Wang; C. Saricks

2010-01-01

202

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

PubMed

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

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

2013-09-06

203

Methane generation in landfills  

Microsoft Academic Search

Methane gas is a by-product of landfilling municipal solid wastes (MSW). Most of the global MSW is dumped in non-regulated landfills and the generated methane is emitted to the atmosphere. Some of the modern regulated landfills attempt to capture and utilize landfill biogas, a renewable energy source, to generate electricity or heat. As of 2001, there were about one thousand

Nickolas J. Themelis; Priscilla A. Ulloa

2007-01-01

204

Regional prediction of long-term landfill gas to energy potential.  

PubMed

Quantifying landfill gas to energy (LFGTE) potential as a source of renewable energy is difficult due to the challenges involved in modeling landfill gas (LFG) generation. In this paper a methodology is presented to estimate LFGTE potential on a regional scale over a 25-year timeframe with consideration of modeling uncertainties. The methodology was demonstrated for the US state of Florida, as a case study, and showed that Florida could increase the annual LFGTE production by more than threefold by 2035 through installation of LFGTE facilities at all landfills. The estimated electricity production potential from Florida LFG is equivalent to removing some 70 million vehicles from highways or replacing over 800 million barrels of oil consumption during the 2010-2035 timeframe. Diverting food waste could significantly reduce fugitive LFG emissions, while having minimal effect on the LFGTE potential; whereas, achieving high diversion goals through increased recycling will result in reduced uncollected LFG and significant loss of energy production potential which may be offset by energy savings from material recovery and reuse. Estimates showed that the power density for Florida LFGTE production could reach as high as 10 Wm(-2) with optimized landfill operation and energy production practices. The environmental benefits from increased lifetime LFG collection efficiencies magnify the value of LFGTE projects. PMID:21703844

Amini, Hamid R; Reinhart, Debra R

2011-06-23

205

Chemical composition of landfill leachate in a karst area with a Mediterranean climate (Marbella, southern Spain)  

Microsoft Academic Search

Between March 1994 and April 1997, the physical and chemical parameters and chemical composition of the urban solid waste\\u000a leachate of the Marbella landfill (southern Spain) were determined. The data obtained show an ammonium and sodium chloride\\u000a and bicarbonate type, a pH>7 and high mineralization, effectively described by the following parameters: Na+, K+, NH4\\u000a +, Cl– and alkalinity. The chemical

I. Vadillo; F. Carrasco; B. Andreo; A. García de Torres; C. Bosch

1999-01-01

206

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...

207

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 ...

208

Landfill gas generation after mechanical biological treatment of municipal solid waste. Estimation of gas generation rate constants.  

PubMed

Mechanical biological treatment (MBT) of residual municipal solid waste (RMSW) was investigated with respect to landfill gas generation. Mechanically treated RMSW was sampled at a full-scale plant and aerobically stabilized for 8 and 15 weeks. Anaerobic tests were performed on the aerobically treated waste (MBTW) in order to estimate the gas generation rate constants (k,y(-1)), the potential gas generation capacity (L(o), Nl/kg) and the amount of gasifiable organic carbon. Experimental results show how MBT allowed for a reduction of the non-methanogenic phase and of the landfill gas generation potential by, respectively, 67% and 83% (8 weeks treatment), 82% and 91% (15 weeks treatment), compared to the raw waste. The amount of gasified organic carbon after 8 weeks and 15 weeks of treatment was equal to 11.01+/-1.25kgC/t(MBTW) and 4.54+/-0.87kgC/t(MBTW), respectively, that is 81% and 93% less than the amount gasified from the raw waste. The values of gas generation rate constants obtained for MBTW anaerobic degradation (0.0347-0.0803y(-1)) resemble those usually reported for the slowly and moderately degradable fractions of raw MSW. Simulations performed using a prediction model support the hypothesis that due to the low production rate, gas production from MBTW landfills is well-suited to a passive management strategy. PMID:18954969

Gioannis, G De; Muntoni, A; Cappai, G; Milia, S

2008-10-26

209

RECOVERY, PROCESSING, AND UTILIZATION OF GAS FROM SANITARY LANDFILLS  

EPA Science Inventory

The report is organized into seven sections. Following the introduction and conclusions and recommendations, are sections describing: the three-component gas generation phenomenon; analysis and comparison of alternative gas utilizations including the processes necessary to prepar...

210

SALE OF SURPLUS DIGESTER AND LANDFILL GAS TO PUBLIC UTILITIES  

EPA Science Inventory

Methane gas produced by anaerobic digestion of wastewater sludge can be upgraded to pipeline quality and sold to a public utility for injection into a natural gas distribution system. Upgrading the gas typically involves treatment for removal of carbon dioxide and hydrogen sulfid...

211

Comparision of two different ways of landfill gas utilization through greenhouse gas emission reductions analysis and financial analysis.  

PubMed

Greenhouse gas (GHG) emission reductions and utilization of landfill gas (LFG) were researched by comparing LFG displacing the use of natural gas (scenario 2) with electricity generation using LFG (scenario 3) at three different LFG collecting efficiencies; 35, 50 and 65%. The results show that the utilization of LFG in scenario 2 is 1.4 times that in scenario 3. GHG emission reductions generated by scenario 2 are slightly less than that of scenario 3. The GHG emission reductions and utilization of LFG are restricted by LFG collecting efficiencies. It will be helpful to improve the management level of landfill and the GHG emissions reduction by introducing the CDM. However, the utilization of LFG will be still short of financial attractiveness if the LFG collection efficiency is less than 50%. PMID:19767323

Han, Haibin; Qian, Guangren; Long, Jisheng; Li, Shude

2009-09-18

212

Methane recovery from sanitary landfills  

Microsoft Academic Search

Methane recovery from sanitary landfills is surveyed. Anaerobic digestion converts organic materials in the waste to methane and carbon dioxide. Landfill gas recovery wells use the methane for process heat. Eleven examples of landfill recovery in California are surveyed. The Fresh Kills, Staten Island landfill is the largest recovery program. The steps to be taken by a landfill owner\\/operator to

M. L. Wilkey; J. J. Walsh

1983-01-01

213

Landfill bioreactor design and operation  

SciTech Connect

Landfill Bioreactor Design and Operation covers the history and background of landfill technology, research studies of actual bioreactor landfills, expected leachate and gas yields, specific design criteria, operation guidelines, and reuse of landfill sites to avoid having to establish new sites. For anyone looking for an alternative to large, wasteful landfill sites, this book provides a practical alternative to the problem.

Reinhart, D.R. [Univ. of Central Florida, Orlando, FL (United States); Townsend, T. [Univ. of Florida, Gainesville, FL (United States)

1998-12-31

214

Modified landfill gas generation rate model of first-order kinetics and two-stage reaction  

Microsoft Academic Search

This investigation was carried out to establish a new domestic landfill gas (LFG) generation rate model that takes into account\\u000a the impact of leachate recirculation. The first-order kinetics and two-stage reaction (FKTSR) model of the LFG generation\\u000a rate includes mechanisms of the nutrient balance for biochemical reaction in two main stages. In this study, the FKTSR model\\u000a was modified by

Jiajun Chen; Hao Wang; Na Zhang

2009-01-01

215

Environmental and economic assessment of landfill gas electricity generation in Korea using LEAP model  

Microsoft Academic Search

As a measure to establish a climate-friendly energy system, Korean government has proposed to expand landfill gas (LFG) electricity generation capacity. The purpose of this paper is to analyze the impacts of LFG electricity generation on the energy market, the cost of generating electricity and greenhouse gases emissions in Korea using a computer-based software tool called ‘Long-range Energy Alternative Planning

Ho-Chul Shin; Jin-Won Park; Ho-Seok Kim; Eui-Soon Shin

2005-01-01

216

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

PubMed

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. PMID:20888746

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

2011-05-01

217

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

PubMed

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

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

2013-05-16

218

Development of the utilization of combustible gas produced in existing sanitary landfills: Investigation of effects of air inclusion  

NASA Astrophysics Data System (ADS)

The effects of nitrogen and oxygen on landfill gas operations are discussed. A combustible gas mixture composed of methane and carbon dioxide is generated in municipal solid waste landfills. A consequence of the collection of this fuel gas is the inclusion of some air in the collected product. The effects include increased collected and purification costs, reduction in the quality of the fuel gas produced, corrosion, explosion hazards, and interference with odorant systems. The scope of such effects was determined by using landfill data of a gas recovery site as a basis. Useful supplemental fuel gas may be recovered despite the inclusion of air. Recommendations are made for establishing limits for nitrogen and oxygen content and minimizing the costs associated with their presence.

1983-01-01

219

Quantifying methane oxidation in a landfill-cover soil by gas push-pull tests  

SciTech Connect

Methane (CH{sub 4}) oxidation by aerobic methanotrophs in landfill-cover soils decreases emissions of landfill-produced CH{sub 4} to the atmosphere. To quantify in situ rates of CH{sub 4} oxidation we performed five gas push-pull tests (GPPTs) at each of two locations in the cover soil of the Lindenstock landfill (Liestal, Switzerland) over a 4 week period. GPPTs consist of the injection of a gas mixture containing CH{sub 4}, O{sub 2} and noble gas tracers followed by extraction from the same location. Quantification of first-order rate constants was based upon comparison of breakthrough curves of CH{sub 4} with either Ar or CH{sub 4} itself from a subsequent inactive GPPT containing acetylene as an inhibitor of CH{sub 4} oxidation. The maximum calculated first-order rate constant was 24.8 {+-} 0.8 h{sup -1} at location 1 and 18.9 {+-} 0.6 h{sup -1} at location 2. In general, location 2 had higher background CH{sub 4} concentrations in vertical profile samples than location 1. High background CH{sub 4} concentrations in the cover soil during some experiments adversely affected GPPT breakthrough curves and data interpretation. Real-time PCR verified the presence of a large population of methanotrophs at the two GPPT locations and comparison of stable carbon isotope fractionation of CH{sub 4} in an active GPPT and a subsequent inactive GPPT confirmed that microbial activity was responsible for the CH{sub 4} oxidation. The GPPT was shown to be a useful tool to reproducibly estimate in situ rates of CH{sub 4} oxidation in a landfill-cover soil when background CH{sub 4} concentrations were low.

Gomez, K.E. [Institute of Biogeochemistry and Pollutant Dynamics, ETH Zuerich, Universitaetstrasse 16, 8092 Zuerich (Switzerland)], E-mail: gomezke@hotmail.com; Gonzalez-Gil, G.; Lazzaro, A. [Institute of Biogeochemistry and Pollutant Dynamics, ETH Zuerich, Universitaetstrasse 16, 8092 Zuerich (Switzerland); Schroth, M.H. [Institute of Biogeochemistry and Pollutant Dynamics, ETH Zuerich, Universitaetstrasse 16, 8092 Zuerich (Switzerland)], E-mail: martin.schroth@env.ethz.ch

2009-09-15

220

Quantifying methane oxidation in a landfill-cover soil by gas push-pull tests.  

PubMed

Methane (CH(4)) oxidation by aerobic methanotrophs in landfill-cover soils decreases emissions of landfill-produced CH(4) to the atmosphere. To quantify in situ rates of CH(4) oxidation we performed five gas push-pull tests (GPPTs) at each of two locations in the cover soil of the Lindenstock landfill (Liestal, Switzerland) over a 4 week period. GPPTs consist of the injection of a gas mixture containing CH(4), O(2) and noble gas tracers followed by extraction from the same location. Quantification of first-order rate constants was based upon comparison of breakthrough curves of CH(4) with either Ar or CH(4) itself from a subsequent inactive GPPT containing acetylene as an inhibitor of CH(4) oxidation. The maximum calculated first-order rate constant was 24.8+/-0.8 h(-1) at location 1 and 18.9+/-0.6 h(-1) at location 2. In general, location 2 had higher background CH(4) concentrations in vertical profile samples than location 1. High background CH(4) concentrations in the cover soil during some experiments adversely affected GPPT breakthrough curves and data interpretation. Real-time PCR verified the presence of a large population of methanotrophs at the two GPPT locations and comparison of stable carbon isotope fractionation of CH(4) in an active GPPT and a subsequent inactive GPPT confirmed that microbial activity was responsible for the CH(4) oxidation. The GPPT was shown to be a useful tool to reproducibly estimate in situ rates of CH(4) oxidation in a landfill-cover soil when background CH(4) concentrations were low. PMID:19525106

Gómez, K E; Gonzalez-Gil, G; Lazzaro, A; Schroth, M H

2009-06-13

221

Design and operation of a demonstration sanitary landfill developed to optimize the generation and capture of combustible gas  

SciTech Connect

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 in the San Fernando Valley, north of Los Angeles, California, The site, earth work, municipal waste, and processing of waste were provided by the Bureau of Sanitation, Department of Public Works, city of Los Angeles. Municipal waste in each cell is contained in a 30-mil thick polyvinyl chloride (PVC) plastic sheeting that forms a virtually gas-tight envelope. Three pairs of cells were filled with waste: two cells with as-collected urban waste, two with shredded waste, and two with shredded and air classified waste. One cell from each pair was used as a control cell; the other cell was used as an experimental cell. Systems were provided for adding measured amounts of water, removing and recirculating leachate, extracting gas, and measuring gas flow. During the demonstration period, the rate of gas production, quantity and composition of gas produced, and internal cell characteristics were measured to determine the effects of mechanical processing (shredding and air classifying) moisture content, and leachate pH.

Not Available

1983-03-01

222

Two years of operation completed for large landfill gas power plant  

SciTech Connect

The V16 GEC Alsthom Ruston Diesels RK270GS engine, one of the largest lean-burn, spark-ignited engines running on landfill gas anywhere in the world, has just completed its second year of commercial operation at the Calvert landfill site. It has developed 2.8 MW at 1000 r/min and drives a Brush air-cooled alternator, feeding electricity at 11 kV into the area grid 24 hours a day. The site has already taken some seven million tonnes of waste and will eventually absorb around 20 million over a projected life of 20-30 years. By that time, electrical output from the site should amount to about 13 MW. 3 figs.

Mullins, P.

1994-10-01

223

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

SciTech Connect

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.

McVey, M.D.; Goering, T.J. [GRAM, Inc., Albuquerque, NM (United States); Peace, J.L. [Sandia National Labs., Albuquerque, NM (United States)

1996-02-01

224

Determination of siloxanes and VOC in landfill gas and sewage gas by canister sampling and GC-MS/AES analysis  

SciTech Connect

Biogases such as landfill gas and sewage gas undergo a combustion process which is generating electric energy. Since several trace compounds such as siloxanes (also halogenated and sulfur compounds) are known to cause severe problems to these gas combustion engines, they are of particular interest. In this work, a new technique for sampling, identification, and quantification of siloxanes and volatile organic carbon (VOC) in landfill gas and sewage gas is presented. After sample collection using evacuated stainless steel canisters biogas was analyzed by gas chromatography-mass spectrometry/atomic emission spectroscopy (GC-MS/AES). Using gas canisters, the sampling process was simplified (no vacuum pump needed), and multiple analysis was possible. The simultaneous application of MSD and AED allowed a rapid screening of silicon compounds in the complex biogases. Individual substances were identified independently both by MSD analysis and by determination of their elemental constitution. Quantification of trace compounds was achieved using a 30 component external standard containing siloxanes, organochlorine and organosulfur compounds, alkanes, terpenes, and aromatic compounds. Precision, linearity, and detection limits have been studied. In real samples, concentrations of silicon containing compounds (trimethylsilanol, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasilioxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane) in the mg/m{sub 3} range have been observed.

Schweigkofler, M.; Niessner, R.

1999-10-15

225

Methane from landfills  

SciTech Connect

A review on the feasibility and status of recovering CH4 from landfills. A typical landfill gas recovery program is described and includes tests to quantify the recoverable volume of gas and an evaluation of economic feasibility based on factors such as the location of the customers for the gas, legal restrictions, and the technology required to upgrade the raw gas. Planned commercial ventures to recover landfill gas are discussed briefly.

Catell, R.B.

1982-01-01

226

Demonstration of fuel cells to recover energy from landfill gas. Phase 2. Pretreatment system performance measurement. Final report, September 1991February 1994  

Microsoft Academic Search

The report describes Phase II of a demonstration of the utilization of commercial phosphoric acid fuel cells to recovery 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 impurities from landfill gas which are detrimental to the fuel cell. The GPU successfully removed the

J. C. Trocciola; J. L. Preston

1995-01-01

227

Radiolytic Bubble Gas Hydrogen Compositions  

SciTech Connect

Radioactive waste solids can trap bubbles containing hydrogen that may pose a flammability risk if they are disturbed and hydrogen is released. Whether a release is a problem or not depends, among other things, on the hydrogen composition of the gas. This report develops a method for estimating the hydrogen composition of trapped bubbles based on waste properties.

Hester, J.R.

2003-02-05

228

Composition of Coalbed Gas.  

National Technical Information Service (NTIS)

Samples of gas were obtained directly from the coalbed during drilling of horizontal and vertical boreholes in six different formations. The samples were analyzed by gas chromatography for C1 to C5 hydrocarbons and for O2, N2, H2, He, and CO2. Methane in ...

A. G. Kim

1973-01-01

229

Landfill operation for carbon sequestration and maximum methane emission control.  

National Technical Information Service (NTIS)

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 gener...

D. Augenstein

1999-01-01

230

Emerging technologies for the management and utilization of landfill gas. Final report, August 1994-August 1997  

SciTech Connect

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 utilization of methane (CH4) and carbon dioxide (CO2) from LFG. The emerging technologies that are considered to be Tier 1 are: (1) phosphoric acid fuel cells, (2) processes for converting CH4 from LFG to compressed LFG for vehicle fuel or other fuel uses, and (3) use of LFG as a fuel source for leachate evaporation systems. The Tier 2 technologies covered in the report are: (1) operation of landfills as anaerobic bioreactors, (2) operation of landfills are aerobic bioreactors, (3) production of ethanol from LFG, (4) production of commercial CO2 from LFG, and (5) use of LFG to provide fuel for heat and CO2 enhancement in greenhouses. Tier 3 technologies, considered as potentially applicable for LFG. include Stirling and Organic Rankine Cycle engines.

Roe, S.; Reisman, J.; Strait, R.; Doorn, M.

1998-02-01

231

Ionic composition and greenhouse gases evaluation in Tietê River sediment and mud landfill  

NASA Astrophysics Data System (ADS)

There are 39 cities composing the Metropolitan Area of São Paulo (MASP) which has grown seven times during the last sixty years, reaching, in 2011, 19.3 million inhabitants. This fact associated with a strong industrial development provoked, among other consequences, a disordered urbanization along the most important river of the region: Tietê. About 100 Km of its 1,150 Km full extension crosses MASP and, during the 60's, Marginal Tietê roadway was constructed, occupying the river banks as access routes. Tietê River was straightened and several landfills were created with its deposit (sediment and mud). EACH-USP (46.50 W, 23.48 S) lies nowadays in one of these areas, where this work has been developed. Therefore, the goal is to evaluate the chemical composition (ionic and gases) and its variability in function of the depth levels using three wells, from 0.60 to 9.0 m of depth. The wells were perforated in September 2011, end of the dry weather. Each well owns a homemade multiport sampling device (HMSD), being possible to push gas and/or water up from 15 available ports. The gases measurements were carried out using a GEM-2000 plus (Landtec) portable analyzer. Aqueous samples containing solid material were taken at each level depth from ports of the HMSD. However, no water was found in some levels. All samples were kept cooled until analysis procedures. After decantation of the solid material, the supernatant liquid was divided in two portions, being its conductivity (Micronal conductimeter) and pH (pH-meter Metrohm 654 with combined glass electrode) measured with the former and ionic analysis with the latter, in which all samples were filtered (Millex 0.22 micrometer pores) before each ionic chromatographic analysis, using Metrohm 850 System, for the ions: sodium, ammonium, potassium, calcium, magnesium, chloride, nitrate and sulfate. The first sampling stage was carried out during November and December 2011 in the beginning of rainy season in the mid Spring. From all the analysis performed, a large variability of the results may be observed for both gases and ionic composition not only among the wells, but also among the different depth levels. Vertically, one of the wells (W2) showed the same percentage of gases, methane 55% and carbon dioxide 45%, at all depth levels, while the other two wells (W1 and W3) presented these gases percentages only under 5.0 m deep. Concerning oxygen, 25% of this gas was detected at 1.0 m under the surface in W1 and W3. In relation to aqueous samples, the most acidity was observed near the surface (0.60 m deep, W1), pH 4.65, while pH 7.88 was obtained under 5.0 m deep (W3). For ionic concentrations a large range was observed considering all wells, being the lowest values for sulfate, from 0.60 to 20 mg/l, and the highest values for ammonium, between 14 and 53 mg/l. These results variability can be associated to the different soil composition layers, as well as to the biodegradation process and the time confinement of the river material deposit.

La-Scalea, M. A.; Fornaro, A.; Abreu, E. L.; Mendonça, C. A.

2012-04-01

232

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

Microsoft Academic Search

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

Thorneloe

1993-01-01

233

Renewable Energy, Landfill Gas and EfW: Now, Next and Future  

Microsoft Academic Search

The United Kingdom (UK) has traditionally used landfill disposal as the predominant method of waste management. However, landfilling is unsustainable due to its harmful effects on the environment and public health. Under the European Union (EU) Landfill Directive, member nations are now required to divert biodegradable municipal waste (BMW) from landfills. The UK has also committed to the EU Renewable

K A Adu-Gyamfi; R Villa; F Coulon

234

Methane from landfills  

Microsoft Academic Search

The recovery and utilization of methane generated in sanitary landfills provides the nation with an opportunity to simultaneously develop an alternative energy source and negate potential hazards. Utilization as a fuel of the combustible gas generated in sanitary landfills has been found to virtually eliminate the twin hazards of explosion and asphyxiation that have long been associated with landfill operations.

R. E. Zimmerman; M. L. Wilkey

1979-01-01

235

Landfill gas energy utilization experience: Discussion of technical and non-technical issues, solutions, and trends. Final report, January 1992September 1994  

Microsoft Academic Search

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 U.S. The report also provides the history and trends of the landfill gas industry in the

M. Doorn; J. Pacey; D. Augenstein

1995-01-01

236

PRESENT AND LONG-TERM COMPOSITION OF MSW LANDFILL LEACHATE: A REVIEW. (R827580)  

EPA Science Inventory

The major potential environmental impacts related to landfill leachate are pollution of groundwater and surface waters. Landfill leachate contains pollutants that can be categorized into four groups (dissolved organic matter, inorganic macrocomponents, heavy metals, and xenobi...

237

Fatal flaws in measuring landfill gas generation rates by empirical well testing.  

PubMed

Well testing procedures, such as the Tier 3 methodology specified in the U.S. Code of Federal Regulations (CFR) Subtitle D, are commonly used for directly estimating landfill gas (LFG) emissions at municipal solid waste (MSW) landfills. Similar procedures are also used to estimate LFG generation rates for the design of LFG-to-energy projects. These methodologies assume that the LFG generation rate equals the extraction rate of a test gas well within its radius of influence (ROI). The ROI is defined as the distance from the extraction well at which the induced pressure drop is immeasurable by some standard of precision. Based on fluid dynamic principles, Tier 3 and similar methodologies are demonstrated to be incapable of providing reliable estimates of the LFG generation rate. These tests may either over- or underestimate the LFG generation rate depending on the precision with which the ROI is determined, but they will only coincidentally produce an estimate that accurately represents the actual LFG generation rate. Fluid dynamic principles dictate that the actual LFG generation rate can only be estimated if the pneumatic properties of the refuse and cover materials as well as the excess pressure in the refuse caused by LFG generation are known or can be estimated. PMID:12708510

Walter, Gary R

2003-04-01

238

Energy potential of modern landfills  

Microsoft Academic Search

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.

Bogner

1990-01-01

239

Web-based monitoring of year-length deployments of autonomous gas sensing platforms on landfill sites  

Microsoft Academic Search

This paper describes multiple field deployments of autonomous gas monitoring platforms spanning durations in excess of 12 months. These trials form part of an on-going collaboration with the Environmental Protection Agency (EPA) in monitoring landfill migration of greenhouse gases, i.e. methane (CH4) and carbon dioxide (CO2). Target gas concentrations were automatically recorded via infrared (IR) gas sensors calibrated for the

Fiachra Collins; Dylan Orpen; Cormac Fay; Colum Foley; Alan F. Smeaton; Dermot Diamond

2011-01-01

240

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

PubMed

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

Levis, James W; Barlaz, Morton A

2011-05-27

241

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

242

Method for treating landfill leachate  

SciTech Connect

A method is described for removing contaminants from leachate of a landfill which produces landfill gas, comprising the steps of: (a) combusting the landfill gas to produce combustion products; (b) heating the leachate with said combustion products; (c) removing contaminants from the leachate by gas stripping; and (d) reducing the pH of the leachate with said combustion products.

Singhvi, S.S.

1993-08-24

243

Methodologies for quantifying pollution prevention benefits from landfill gas control and utilization. Final report, November 1993October 1994  

Microsoft Academic Search

A combination of mass balance methods and emission factors based on source data can be used to make comparisons in air pollution potential between different landfill gas (LFG) control or utilization options. This report describes the development of emission factors for controlled primary pollutants (e.g., nonmethane organic compounds) and secondary air pollutants (e.g., carbon monoxide). The following criteria air pollutants

S. M. Roe; P. G. Fields; R. E. Coad

1995-01-01

244

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

PubMed

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

Haubrichs, R; Widmann, R

2006-01-04

245

2006 Update: The State of U.S. Landfill Gas Utilization Projects  

Microsoft Academic Search

This article discusses the U.S. Environmental Protection Agency's Landfill Methane Outreach Program. Municipal solid waste landfills are the largest source of human-related methane emissions in the United States. Instead of allowing LFG to escape into the air, it can be captured, converted, and used as an energy source. The Landfill Methane Outreach Program is a voluntary assistance program that helps

Rachel Goldstein

2007-01-01

246

Methylated mercury species in municipal waste landfill gas sampled in Florida, USA1  

Microsoft Academic Search

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

S. E. Lindberga; D. Wallschl; E. M. Prestbob; D. Reinhartd; Frontier Geosciences

247

Simulation model for gas diffusion and methane oxidation in landfill cover soils  

Microsoft Academic Search

Landfill cover soils oxidize a considerable fraction of the methane produced by landfilled waste. Despite many efforts this oxidation is still poorly quantified. In order to reduce the uncertainties associated with methane oxidation in landfill cover soils, a simulation model was developed that incorporates Stefan–Maxwell diffusion, methane oxidation, and methanotrophic growth. The growth model was calibrated to laboratory data from

Alex De Visscher; Oswald Van Cleemput

2003-01-01

248

Computer simulation of gas generation and transport in landfills. III: Development of lanfills’ optimal model  

Microsoft Academic Search

In Parts I and II of this series a 3D model was developed for transport and reaction of gaseous mixtures in landfills, and was utilized, through computer simulations, to investigate the effect of various factors on the gases’ concentrations and the landfill's total pressure, under quasi-steady state and dynamic conditions. A fundamental problem with modelling of landfills is the severe

Raudel Sanchez; Theodore T. Tsotsis; Muhammad Sahimi

2007-01-01

249

Acceleration of landfill stabilization using leachate recycle  

Microsoft Academic Search

A leachate recycle system was constructed and operated at an existing lined landfill in North-Central Florida to observe the effects of leachate recycle on landfill stabilization. Samples of leachate, landfill gas, and landfilled solid waste were collected and analyzed throughout a four-year period, before and after the start of leachate recycle. The settlement of landfilled waste was also measured in

T. G. Townsend; W. L. Miller; Hyung-Jib Lee; J. F. K. Earle

1996-01-01

250

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

NASA Astrophysics Data System (ADS)

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.

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

2007-12-01

251

Computer simulation of gas generation and transport in landfills. V: Use of artificial neural network and the genetic algorithm for short- and long-term forecasting and planning  

Microsoft Academic Search

In the first four parts of this series a three-dimensional model was developed for transport and reaction of gaseous mixtures in a landfill. An optimization technique was also utilized in order to determine a landfill's spatial distributions of the permeability, porosity, the tortuosity factors, and the total gas generation potential of the wastes, given a limited amount of experimental data.

Hu Li; Raudel Sanchez; S. Joe Qin; Halil I. Kavak; Ian A. Webster; Theodore T. Tsotsis; Muhammad Sahimi

2011-01-01

252

Review of past research and proposed action plan for landfill gas-to-energy applications in India.  

PubMed

Open dumps employed for disposal of municipal solid waste (MSW) are generally referred to as landfills and have been traditionally used as the ultimate disposal method in India. The deposition of MSW in open dumps eventually leads to uncontrolled emission of landfill gas (LFG). This article reviews the MSW disposal practices and LFG emissions from landfills in India during the period 1994 to 2011. The worldwide trend of feasibility of LFG to energy recovery projects and recent studies in India indicate a changed perception of landfills as a source of energy. However, facilitating the implementation of LFG to energy involves a number of challenges in terms of technology, developing a standardized framework and availability of financial incentives. The legislative framework for promotion of LFG to energy projects in India has been reviewed and a comprehensive strategy and action plan for gainful LFG recovery is suggested. It is concluded that the market for LFG to energy projects is not mature in India. There are no on-ground case studies to demonstrate the feasibility of LFG to energy applications. Future research therefore should aim at LFG emission modeling studies at regional level and based on the results, pilot studies may be conducted for the potential sites in the country to establish LFG to energy recovery potential from these landfills. PMID:23255613

Siddiqui, Faisal Zia; Zaidi, Sadaf; Pandey, Suneel; Khan, Mohd Emran

2013-01-01

253

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

NASA Astrophysics Data System (ADS)

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.

Zhang, Yuanyuan; Yue, Dongbei; Nie, Yongfeng

2012-08-01

254

Environmental assessment of gas management options at the Old Ammässuo landfill (Finland) by means of LCA-modeling (EASEWASTE).  

PubMed

The current landfill gas (LFG) management (based on flaring and utilization for heat generation of the collected gas) and three potential future gas management options (LFG flaring, heat generation and combined heat and power generation) for the Old Ammässuo landfill (Espoo, Finland) were evaluated by life-cycle assessment modeling. The evaluation accounts for all resource utilization and emissions to the environment related to the gas generation and management for a life-cycle time horizon of 100 yr. The assessment criteria comprise standard impact categories (global warming, photo-chemical ozone formation, stratospheric ozone depletion, acidification and nutrient enrichment) and toxicity-related impact categories (human toxicity via soil, via water and via air, eco-toxicity in soil and in water chronic). The results of the life-cycle impact assessment show that disperse emissions of LFG from the landfill surface determine the highest potential impacts in terms of global warming, stratospheric ozone depletion, and human toxicity via soil. Conversely, the impact potentials estimated for other categories are numerically-negative when the collected LFG is utilized for energy generation, demonstrating that net environmental savings can be obtained. Such savings are proportional to the amount of gas utilized for energy generation and the gas energy recovery efficiency achieved, which thus have to be regarded as key parameters. As a result, the overall best performance is found for the heat generation option - as it has the highest LFG utilization/energy recovery rates - whereas the worst performance is estimated for the LFG flaring option, as no LFG is here utilized for energy generation. Therefore, to reduce the environmental burdens caused by the current gas management strategy, more LFG should be used for energy generation. This inherently requires a superior LFG capture rate that, in addition, would reduce fugitive emissions of LFG from the landfill surface, bringing further environmental benefits. PMID:19081238

Manfredi, Simone; Niskanen, Antti; Christensen, Thomas H

2008-12-09

255

Present and Long-Term Composition of MSW Landfill Leachate: A Review  

Microsoft Academic Search

The major potential environmental impacts related to landfill leachate are pollution of groundwater and surface waters. Landfill leachate contains pollutants that can be categorized into four groups (dissolved organic matter, inorganic macrocomponents, heavy metals, and xenobiotic organic compounds). Existing data show high leachate concentrations of all components in the early acid phase due to strong decomposition and leaching. In the

Peter Kjeldsen; Morton A. Barlaz; Alix P. Rooker; Anders Baun; Anna Ledin; Thomas H. Christensen

2002-01-01

256

Ammoniacal nitrogen and COD removal from semi-aerobic landfill leachate using a composite adsorbent: Fixed bed column adsorption performance  

Microsoft Academic Search

The performance of a carbon-mineral composite adsorbent used in a fixed bed column for the removal of ammoniacal nitrogen and aggregate organic pollutant (COD), which are commonly found in landfill leachate, was evaluated. The breakthrough capacities for ammoniacal nitrogen and COD adsorption were 4.46 and 3.23mg\\/g, respectively. Additionally, the optimum empty bed contact time (EBCT) was 75min. The column efficiency

Azhar Abdul Halim; Hamidi Abdul Aziz; Megat Azmi Megat Johari; Kamar Shah Ariffin; Mohd. Nordin Adlan

2010-01-01

257

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

SciTech Connect

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.

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

2000-10-20

258

Use of gas push-pull tests for the measurement of methane oxidation in different landfill cover soils.  

PubMed

In order to optimise methane oxidation in landfill cover soils, it is important to be able to accurately quantify the amount of methane oxidised. This research considers the gas push-pull test (GPPT) as a possible method to quantify oxidation rates in situ. During a GPPT, a gas mixture consisting of one or more reactive gases (e.g., CH(4), O(2)) and one or more conservative tracers (e.g., argon), is injected into the soil. Following this, the mixture of injected gas and soil air is extracted from the same location and periodically sampled. The kinetic parameters for the biological oxidation taking place in the soil can be derived from the differences in the breakthrough curves. The original method of Urmann et al. (2005) was optimised for application in landfill cover soils and modified to reduce the analytical effort required. Optimised parameters included the flow rate during the injection phase and the duration of the experiment. 50 GPPTs have been conducted at different landfills in Germany during different seasons. Generally, methane oxidation rates ranged between 0 and 150 g m(soil air)(-3)h(-1). At one location, rates up to 440 g m(soil air)(-3)h(-1) were measured under particularly favourable conditions. The method is simple in operation and does not require expensive equipment besides standard laboratory gas chromatographs. PMID:20971626

Streese-Kleeberg, Jan; Rachor, Ingke; Gebert, Julia; Stegmann, Rainer

2010-10-23

259

Instrumentation for continuous monitoring of meteorological variables and soil gas pressure in landfill cover  

SciTech Connect

To examine changes in soil gas pressure relative to changes in atmospheric pressure and other meteorological variables, weather station sensors and electronic pressure transducers were interfaced with an RCA COSMAC microcomputer. The microcomputer control permitted simultaneous acquisition of pressure and meteorological data on cassette tape. Because the RCA unit uses CMOS circuitry, it can be battery operated, and is therefore well suited for collecting data at remote locations on landfills. A tape I/O board, an A/D converter board and two custom boards were required additions to the basic CDP18S601 board for this application. Meteorological data, including wind speed, wind direction, air temperature, precipitation, and solar radiation, were monitored using a Climatronics EWS system. Barometric pressure and soil gas pressures on subsurface probes were monitored using electronic pressure transducers with a 10 to 20 psia range. Cassette tape output was dumped directly to WYLBUR files on the Argonne National Laboratory (ANL) IBM 3033 mainframe for subsequent data analysis.

Moore, C.; Vogt, M.; Bogner, J.

1986-09-01

260

Effects of compost biocovers on gas flow and methane oxidation in a landfill cover.  

PubMed

Previous publications described the performance of biocovers constructed with a compost layer placed on select areas of a landfill surface characterized by high emissions from March 2004 to April 2005. The biocovers reduced CH(4) emissions 10-fold by hydration of underlying clay soils, thus reducing the overall amount of CH(4) entering them from below, and by oxidation of a greater portion of that CH(4). This paper examines in detail the field observations made on a control cell and a biocover cell from January 1, 2005 to December 31, 2005. Field observations were coupled to a numerical model to contrast the transport and attenuation of CH(4) emissions from these two cells. The model partitioned the biocover's attenuation of CH(4) emission into blockage of landfill gas flow from the underlying waste and from biological oxidation of CH(4). Model inputs were daily water content and temperature collected at different depths using thermocouples and calibrated TDR probes. Simulations of CH(4) transport through the two soil columns depicted lower CH(4) emissions from the biocover relative to the control. Simulated CH(4) emissions averaged 0.0gm(-2)d(-1) in the biocover and 10.25gm(-2)d(-1) in the control, while measured values averaged 0.04gm(-2)d(-1) in the biocover and 14gm(-2)d(-1) in the control. The simulated influx of CH(4) into the biocover (2.7gm(-2)d(-1)) was lower than the simulated value passing into the control cell (29.4gm(-2)d(-1)), confirming that lower emissions from the biocover were caused by blockage of the gas stream. The simulated average rate of biological oxidation predicted by the model was 19.2gm(-2)d(-1) for the control cell as compared to 2.7gm(-2)d(-1) biocover. Even though its V(max) was significantly greater, the biocover oxidized less CH(4) than the control cell because less CH(4) was supplied to it. PMID:19131233

Abichou, Tarek; Mahieu, Koenraad; Yuan, Lei; Chanton, Jeffery; Hater, Gary

2009-01-07

261

Laboratory and field screening strategies for measuring volatile organic compounds in landfill gas  

SciTech Connect

Distinct patterns often exist in the presence and absence of hazardous contaminants in the environment. These patterns can be used to select efficient screening tools, or groups of compounds that provide the most information on overall occurrences of a larger target group of compounds. By using these screens to indicate whether a sample is contaminated with detectable amounts of the compounds of interest, attention can be focused on those samples considered most likely to contain measurable concentrations of targeted compounds. The cost savings that result from eliminating samples that are most likely uncontaminated can be applied to obtaining additional samples that more accurately characterize the spatial or temporal variability of the environmental problem. In a retrospective application of screening techniques to the State of California's database of volatile organic compounds in landfill gas, two laboratory screening compounds, perchloroethylene and methylene chloride, represent over 95% of the total number of positive detections of a target group of 10 volatile organic compounds. Benzene and vinyl chloride, two field screening compounds that were selected using the characteristics of commercially available colorimetric detector tubes, recorded 74% of the total contaminant detections and a 52% savings in analytical costs as compared to an exhaustive analysis of every sample for all 10 volatile organic compounds. The number of detections recorded could have been improved if more sensitive and less selective field screening devices were available.

Emerson, C.W.

1999-11-01

262

Effective tools for Managing odours from landfill facilities in Ireland  

Microsoft Academic Search

Waste management facilities and especially landfill sites produce odours. Like the majority of industries, the operation of landfills, is faced with the issue of preventing odours causing impact to the public at large. Design, operational and management techniques can reduce the impact of odours from landfills. Containment of landfill gas through optimising landfill cover, gas collection systems and management techniques

J. W. Case; B. A. Sheridan; M. Henry

263

Landfills in the year 2000  

SciTech Connect

The 21st century landfill will have the proper public and customer image from the environmental standpoint. The landfill of the 21st century will provide diverse services right at the landfill. You will not only have burial of waste, but a bioremediation pad for handling certain petro-chemical soils and a reuse area for concrete and rubble. Landfills will reuse special wastes. The industry now has more than seven specialized industrial wastes approved for landfill cover. So, instead of spending money for landfill cover or alternative cover like foam, landfills will actually get paid for the landfill cover. The landfill of the 21st century will have some level of recycling and composting. The sites will broaden their service base to make sure that the customer will be able to bring the wide variety of waste to one place. All of this technology will be designed to function at the landfill to keep waste out of the landfill. From a regulatory standpoint, obviously 21st century landfills will exceed all of the standards. It will be a given that the landfill will have liners, leachate collection, leachate treatment, and gas recovery and, probably, reuse. The 21st century landfill will receive a very different waste type. It will have less municipal solid waste and a greater volume of special waste-compatible, nonhazardous waste.

Glebs, B. (Superior Environmental Services, Madison, WI (United States))

1994-03-01

264

Energy potential of modern landfills  

SciTech Connect

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.

Bogner, J.E.

1990-01-01

265

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

NASA Astrophysics Data System (ADS)

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.

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

1982-02-01

266

Instrumentation of Two Experimental Sanitary Landfills  

Microsoft Academic Search

An experimental study of the behavior of sanitary landfills is reported. Two facilities are described: a simulated land-fill operated under laboratory conditions and a field landfill operated under natural environmental conditions. This paper emphasizes environmental control and temperature monitoring, although the complete study includes evaluation of liquid and gas pollutant generation. The simulated landfill is a laboratory lysimeter 6 feet

A. A. Fungaroli

1970-01-01

267

Impact of gas composition on natural gas storage by adsorption  

Microsoft Academic Search

Adsorption storage is the most promising low-pressure alternative for storing natural gas, but some operational difficulties hinder the success of this technology. From a modeling perspective, this article addresses the impact of gas composition on the cyclic behavior of adsorptive natural gas storage systems. The cyclic operation of an onboard storage reservoir is modeled as a series of consecutive two-step

José P. B. Mota

1999-01-01

268

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

NASA Astrophysics Data System (ADS)

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 °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 CO2, CH4, H2, NH3, CO and NO2 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 NO2 presence in the multicomponent mixture LFG. The NO2 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 NO2 concentrations of 3.3 ppm and 330 ppb dispersed in the LFG, respectively, with a wide NO2 gas concentration range measured from 0.33 to 3.3 ppm, at the sensor temperature of 150 °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 µm 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 demonstrates high sensitivity by providing minimal sub-ppm level detection, e.g., download up to 100 ppb NO2, at the sensor temperature of 150 °C. The gas sensitivity of the CNT sensor array depends on operating temperature, showing a lower optimal temperature of maximum sensitivity for the metal-decorated CNT sensors compared to unmodified CNT sensors. Results indicate that the recovery mechanisms in the CNT chemiresistors can be altered by a rapid heating pulse from room temperature to about 110 °C. A comparison of the NO2 gas sensitivity for the chemiresistors based on disorderly networked CNTs and vertically aligned CNTs is also reported. Cross-sensitivity towards relative humidity of the CNT sensors array is investigated. Finally, the sensing properties of the metal-decorated and vertically aligned CNT sensor arrays are promising to monitor gas events in the LFG for practical applications with low power consumption and moderate sensor temperature.

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

2010-03-01

269

Dual Frequency Acoustic Gas Composition Analyzer.  

National Technical Information Service (NTIS)

The patent application describes an apparatus for determining the composition of a gas by measuring the acoustic impedence and absorption of a gas at two distinct frequencies. The velocity variations due to the presence of a gas in a fixed length column a...

J. E. Jacobs

1974-01-01

270

Evaluation of landfill gas production and emissions in a MSW large-scale Experimental Cell in Brazil.  

PubMed

Landfill gas (LFG) emissions from municipal solid waste (MSW) landfills are an important environmental concern in Brazil due to the existence of several uncontrolled disposal sites. A program of laboratory and field tests was conducted to investigate gas generation in and emission from an Experimental Cell with a 36,659-ton capacity in Recife/PE - Brazil. This investigation involved waste characterisation, gas production and emission monitoring, and geotechnical and biological evaluations and was performed using three types of final cover layers. The results obtained in this study showed that waste decomposes 4-5 times faster in a tropical wet climate than predicted by traditional first-order models using default parameters. This fact must be included when considering the techniques and economics of projects developed in tropical climate countries. The design of the final cover layer and its geotechnical and biological behaviour proved to have an important role in minimising gas emissions to the atmosphere. Capillary and methanotrophic final cover layers presented lower CH(4) flux rates than the conventional layer. PMID:21349694

Maciel, Felipe Jucá; Jucá, José Fernando Thomé

2011-02-23

271

Utility's role in landfill methane recovery  

SciTech Connect

A review. The manufacture of CH4 containing gas from municipal solid-waste landfills, environmental problems of landfills and benefits of landfill-gas recovery, and the technology and financial risks of large-scale gas production are discussed. (Refs. 3).

Vaszily, J.A.

1981-01-01

272

Methane from Landfills.  

National Technical Information Service (NTIS)

The recovery and utilization of methane generated in sanitary landfills provides the nation with an opportunity to simultaneously develop an alternative energy source and negate potential hazards. Utilization as a fuel of the combustible gas generated in ...

R. E. Zimmerman M. L. Wilkey

1979-01-01

273

Simulation model for gas diffusion and methane oxidation in landfill cover soils.  

PubMed

Landfill cover soils oxidize a considerable fraction of the methane produced by landfilled waste. Despite many efforts this oxidation is still poorly quantified. In order to reduce the uncertainties associated with methane oxidation in landfill cover soils, a simulation model was developed that incorporates Stefan-Maxwell diffusion, methane oxidation, and methanotrophic growth. The growth model was calibrated to laboratory data from an earlier study. There was an excellent agreement between the model and the experimental data. Therefore, the model is highly applicable to laboratory column studies, but it has not been validated with field data. A sensitivity analysis showed that the model is most sensitive to the parameter expressing the maximum attainable methanotrophic activity of the soil. Temperature and soil moisture are predicted to be the environmental factors affecting the methane oxidizing capacity of a landfill cover soil the most. Once validated with field data, the model will enable a year-round estimate of the methane oxidizing capacity of a landfill cover soil. PMID:12957153

De Visscher, Alex; Van Cleemput, Oswald

2003-01-01

274

Thermodynamic stability, spectroscopic identification, and gas storage capacity of CO2-CH4-N2 mixture gas hydrates: implications for landfill gas hydrates.  

PubMed

Landfill gas (LFG), which is primarily composed of CH(4), CO(2), and N(2), is produced from the anaerobic digestion of organic materials. To investigate the feasibility of the storage and transportation of LFG via the formation of hydrate, we observed the phase equilibrium behavior of CO(2)-CH(4)-N(2) mixture hydrates. When the specific molar ratio of CO(2)/CH(4) was 40/55, the equilibrium dissociation pressures were gradually shifted to higher pressures and lower temperatures as the mole fraction of N(2) increased. X-ray diffraction revealed that the CO(2)-CH(4)-N(2) mixture hydrate prepared from the CO(2)/CH(4)/N(2) (40/55/5) gas mixture formed a structure I clathrate hydrate. A combination of Raman and solid-state (13)C NMR measurements provided detailed information regarding the cage occupancy of gas molecules trapped in the hydrate frameworks. The gas storage capacity of LFG hydrates was estimated from the experimental results for the hydrate formations under two-phase equilibrium conditions. We also confirmed that trace amounts of nonmethane organic compounds do not affect the cage occupancy of gas molecules or the thermodynamic stability of LFG hydrates. PMID:22380606

Lee, Hyeong-Hoon; Ahn, Sook-Hyun; Nam, Byong-Uk; Kim, Byeong-Soo; Lee, Gang-Woo; Moon, Donghyun; Shin, Hyung Joon; Han, Kyu Won; Yoon, Ji-Ho

2012-03-13

275

Landfill operation for carbon sequestration and maximum methane emission control.  

National Technical Information Service (NTIS)

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 generat...

D. Augenstein R. Yazdani R. Moore M. Byars J. Kieffer M. Barlaz R. Mehta

2000-01-01

276

Sardinia 1993 Fourth International Landfill Symposium, including meeting of International Energy Agency (IEA) Expert Working Group (EWG) on Landfill Gas. Foreign trip report, October 9--16, 1993.  

National Technical Information Service (NTIS)

J.E. Bogner traveled to Sardinia to participate in the Fourth International Landfill Symposium (Sardinia '93) organized by CISA, the Environmental Sanitary Engineering Center of the University of Cagliari, under the auspices of ISWA, the International Sol...

J. E. Bogner

1993-01-01

277

Performance and bacterial compositions of aged refuse reactors treating mature landfill leachate.  

PubMed

Aged landfill leachates become more refractory over time and difficulty to treat. Recently, aged refuse bioreactors show great promise in treating leachates. In this study, aged refuse bioreactors were constructed to simulate landfill leachate degradation process. The characteristics of leachate were: CODcr, ?2200 mg/L; BOD5, ?280 mg/L; total nitrogen, ?2030 mg/L; and ammonia, ?1900 mg/L. Results showed that bioreactor could remove leachate pollutants effectively at hydraulic loading of 20 L/m3 d. The removal rate reduced when hydraulic loading doubled or temperature lowered. Effluent recirculation could alleviate the temperature effect. Combining aged refuse and slag biofilters could treat leachate more efficiently. Pyrosequencing analysis indicated that bacteria from Pseudomonas, Lysobacter, Bacillus and ?-proteobacter, Flexibacteraceae were more abundant in the samples. The Shannon index decreased at lower temperature, while evenness and equitability increased with recirculation. We suggest that filter medium and temperature may be the main factors for shaping bacterial community structure. PMID:22023964

Xie, Bing; Xiong, Shunzi; Liang, Shaobo; Hu, Chong; Zhang, Xiaojun; Lu, Jun

2011-10-08

278

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...

279

Interfacial Composite Membranes for Gas Separation.  

National Technical Information Service (NTIS)

The program concerns the preparation of a new type of ultrathin gas separation composite membrane. An interfacial polymerized layer was formed on the surface of a composite support membrane consisting of a microporous support overcoated with a 1 to 2 micr...

J. G. Wijmans

1988-01-01

280

Hydrogen sulfide generation in simulated construction and demolition debris landfills: impact of waste composition.  

PubMed

Hydrogen sulfide (H2S) generation in construction and demolition (C&D) debris landfills has been associated with the biodegradation of gypsum drywall. Laboratory research was conducted to observe H2S generation when drywall was codisposed with different C&D debris constituents. Two experiments were conducted using simulated landfill columns. Experiment 1 consisted of various combinations of drywall, wood, and concrete to determine the impact of different waste constituents and combinations on H2S generation. Experiment 2 was designed to examine the effect of concrete on H2S generation and migration. The results indicate that decaying drywall, even alone, leached enough sulfate ions and organic matter for sulfate-reducing bacteria (SRB) to generate large H2S concentrations as high as 63,000 ppmv. The codisposed wastes show some effect on H2S generation. At the end of experiment 1, the wood/drywall and drywall alone columns possessed H2S concentrations > 40,000 ppmv. Conversely, H2S concentrations were < 1 ppmv in those columns containing concrete. Concrete plays a role in decreasing H2S by increasing pH out of the range for SRB growth and by reacting with H2S. This study also showed that wood lowered H2S concentrations initially by decreasing leachate pH values. Based on the results, two possible control mechanisms to mitigate H2S generation in C&D debris landfills are suggested. PMID:16933645

Yang, Kenton; Xu, Qiyong; Townsend, Timothy G; Chadik, Paul; Bitton, Gabriel; Booth, Matthew

2006-08-01

281

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

PubMed

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, ?(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 ?(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 (?), 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 (?) to total porosity (f) (air saturation). Based on the normalized parameters, predictive power-law models for D(p)(?/f) and k(a)(?/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 ?(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. PMID:21813272

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

2011-08-02

282

Environmental Impacts of Solid Waste Landfilling  

Microsoft Academic Search

Inevitable consequences of the practice of solid waste disposal in landfills are gas and leachate generation due primarily to microbial decomposition, climatic conditions, refuse characteristics and landfilling operations. The migration of gas and leachate away from the landfill boundaries and their release into the surrounding environment present serious environmental concerns at both existing and new facilities. Besides potential health hazards,

Mutasem El-Fadel; Angelos N. Findikakis; James O. Leckie

1997-01-01

283

Effect of an uncontrolled fire and the subsequent fire fight on the chemical composition of landfill leachate  

Microsoft Academic Search

Landfill leachates sampled during and after an accidental landfill fire were analysed and the levels of selected metals and chemical compounds compared to those occurring in the leachate under normal conditions. The fire at the landfill site was put out by excavation and cooling by use of water. The investigation during the fire and fire fight revealed a moderate increase

Joar Karsten Øygard; Amund Måge; Elin Gjengedal; Tore Svane

2005-01-01

284

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

PubMed

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. PMID:23792820

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

2013-06-20

285

Mill Seat Landfill Bioreactor Renewable Green Power (NY), Final Report.  

National Technical Information Service (NTIS)

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 transpo...

2010-01-01

286

Economic evaluation of alternative methods of utilizing available landfill gas to cogenerate power at NAS, Miramar. Technical note August 1981March 1982  

Microsoft Academic Search

The Naval Air Station at Miramar, CA, contains the largest active sanitary landfill in San Diego County. It is estimated that the anaerobic decomposition of the organic refuse in this fill is producing sufficient methane to completely satisfy the energy requirements of the base if some means can be found to efficiently utilize this gas as a fuel. An economic

Kodres

1982-01-01

287

78 FR 14773 - U.S. Environmental Solutions Toolkit-Landfill Standards  

Federal Register 2010, 2011, 2012, 2013

...of interest from the following list: (a) Liners (b) Leachate Collection Systems (c) Landfill Gas Collection (d) Bioreactors (e) Controlled Injection Systems (f) Landfill Gas Air Monitoring (g) Landfill Groundwater Monitoring (h)...

2013-03-07

288

ENGINEERING BULLETIN: LANDFILL COVERS  

EPA Science Inventory

Landfill covers are used at Superfund sites to minimize surface water infiltration and control gas migration. In many cases covers are used in conjunction with other waste treatment technologies, such as slurry walls, ground water pump-and-treat systems, and gas collection. This ...

289

PAEs and BPA removal in landfill leachate with Fenton process and its relationship with leachate DOM composition.  

PubMed

An increasing attention has been paid to the trace endocrine disrupting compounds (EDCs) in landfill leachate. In this paper, the removal of EDCs including phthalic acid esters (PAEs) and bisphenol A (BPA) from the fresh and mature landfill leachate by Fenton treatment was studied. More than 40% of PAEs and about 62% of BPA were removed from the raw mature leachate while only 20% of PAEs and 37% of BPA in the raw fresh leachate were reduced, respectively. After the fresh and mature leachates were spiked with PAEs to 1.5 mg L(-1) and BPA to 0.08 mg L(-1), the removal efficiencies of BPA and PAEs increased to more than 88%. The results indicated that the removing efficiencies of the EDCs in the leachate had a relationship with their concentrations, and that the trace levels of EDCs in leachate challenged the treatment capacity of the Fenton process. Most of the EDCs in the enriched leachate were removed by oxidation, which had no clear correlation with the hydrophobicity of the EDCs. The flocculation played an important role in the removal of di-(2-ethylhexyl) phthalate that could not be completely oxidized in the Fenton process, in that the EDCs with high n-octanol/water partition coefficient inclined to precipitate after the Fenton process. The dissolved organic matter (DOM) in the fresh leachate inhibited the EDCs removal more than the DOM in the mature leachate did. Both the composition of the leachate DOM and the characteristics of the EDCs determined the removing efficiencies of the EDCs in the Fenton process. PMID:19520416

He, Pin-Jing; Zheng, Zhong; Zhang, Hua; Shao, Li-Ming; Tang, Qiong-Yao

2009-06-10

290

OUTER LOOP LANDFILL CASE STUDY  

EPA Science Inventory

This presentation will describe the interim data reaulting from a CRADA between USEPA and Waste Management, Inc. at the outer Loop Landfill Bioreactor research project located in Louisville, KY. Recently updated data will be presented covering landfill solids, gas being collecte...

291

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...

292

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 ...

293

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

PubMed

Compared with natural ecosystems and managed agricultural systems, engineered landfills represent a highly managed soil system for which there has been no systematic quantification of emissions from coexisting daily, intermediate, and final cover materials. We quantified the seasonal variability of CH, CO, and NO emissions from fresh refuse (no cover) and daily, intermediate, and final cover materials at northern and southern California landfill sites with engineered gas extraction systems. Fresh refuse fluxes (g m d [± SD]) averaged CH 0.053 (± 0.03), CO 135 (± 117), and NO 0.063 (± 0.059). Average CH emissions across all cover types and wet/dry seasons ranged over more than four orders of magnitude (<0.01-100 g m d) with most cover types, including both final covers, averaging <0.1 g m d with 10 to 40% of surface areas characterized by negative fluxes (uptake of atmospheric CH). The northern California intermediate cover (50 cm) had the highest CH fluxes. For both the intermediate (50-100 cm) and final (>200 cm) cover materials, below which methanogenesis was well established, the variability in gaseous fluxes was attributable to cover thickness, texture, density, and seasonally variable soil moisture and temperature at suboptimal conditions for CH oxidation. Thin daily covers (30 cm local soil) and fresh refuse generally had the highest CO and NO fluxes, indicating rapid onset of aerobic and semi-aerobic processes in recently buried refuse, with rates similar to soil ecosystems and windrow composting of organic waste. This study has emphasized the need for more systematic field quantification of seasonal emissions from multiple types of engineered covers. PMID:21546687

Bogner, Jean E; Spokas, Kurt A; Chanton, Jeffrey P

294

Gas turbine engine and composite parts  

SciTech Connect

A gas turbine engine core engine component blade, vane, disk, side plate, seal, combustor liner, flap, burner case structure, or turbine case structure, is described comprising a silicon carbide fiber reinforced glass composite consisting essentially of about 30% to about 70% by volume silicon carbide fibers in a glass matrix selected from the group consisting of borosilicate glass, high silica content glass, aluminosilicate glass and mixtures thereof, the composite having a fracture toughness exemplified by a critical stress intensity factor above about 15,000 psi (inch)/sup 1/2/, high temperature strength, high temperature oxidation stability and insulating properties.

Prewo, K.M.; Brennan, J.J.

1988-04-19

295

Management of Gas and Leachate in Landfills: Proceedings of the Annual Municipal Solid Waste Research Symposium (3rd) Held at St. Louis, Missouri on March 14, 15 and 16, 1977.  

National Technical Information Service (NTIS)

Contents: Current research on land disposal of municipal solid wastes; Summary of office of solid waste gas and leachate activities; State of Missouri solid waste management activities; Region VII solid waste activities; Landfill research activities in Ca...

S. K. Banerji

1977-01-01

296

Rare gas isotopic compositions in diamonds  

Microsoft Academic Search

RARE gas isotopic compositions such as 40Ar\\/36Ar, 3He\\/4He and 129Xe\\/132Xe in the Earth have provided a powerful tool for understanding the origin and evolution of the terrestrial atmosphere1-4. The isotopic information may be obtained from rare gases trapped in some mantle-derived materials such as volcanic rocks, volcanic xenoliths or volcanic gases. Among these mantle-derived materials, diamond seems to be unique

Nobuo Takaoka; MINORU OZIMA

1978-01-01

297

Acceleration of landfill stabilization using leachate recycle  

SciTech Connect

A leachate recycle system was constructed and operated at an existing lined landfill in North-Central Florida to observe the effects of leachate recycle on landfill stabilization. Samples of leachate, landfill gas, and landfilled solid waste were collected and analyzed throughout a four-year period, before and after the start of leachate recycle. The settlement of landfilled waste was also measured in wetted and dry areas of the landfill. Leachate quality was not dramatically impacted by leachate recycle. Moisture content was significantly greater in the area of the landfill subjected to leachate recycle. Waste temperature and pH measurements indicated that conditions suitable for anaerobic decomposition were present in both the treated and untreated areas. Measurements of solid waste biochemical methane potential and subsidence showed that a greater degree of landfill stabilization had occurred in the leachate recycle area relative to the untreated area.

Townsend, T.G.; Miller, W.L.; Lee, H.J.; Earle, J.F.K. [Univ. of Florida, Gainesville, FL (United States)

1996-04-01

298

MSW LANDFILL BIOREACTOR RESEARCH  

EPA Science Inventory

MSW bioreactors offer an innovative way of optimizing existing landfill volume by actively degrading the waste mass within a waste containment system. Bioreactor leachate, gas, and solids monitoring is part of a 5 year CRADA between US EPA and Waste Mgt., Inc. at the Outer Loop ...

299

Numerical modelling of multiphase flow and transport processes in landfills.  

PubMed

Waste material in municipal landfills can be described as heterogeneous porous media, where flow and transport processes of gases and liquids are combined with local material degradation. This paper deals with the basic formulation of a multiphase flow and transport model applicable to the numerical analysis of coupled transport and reaction processes inside landfills. The transport model treats landfills within the framework of continuum mechanics, where flow and transport processes are described on a macroscopic level. The composition of organic and inorganic matter in the solid phase and its degradation are modelled on a microscopic scale. The degradation model captures the different reaction schemes of various microbial activities. Subsequently, transport and reaction processes have to be coupled, since emissions at the surface and from the drainage layer depend on the flow of leachate and gas, the transport of various substances and heat, and the biodegradation of organic matter. The theoretical considerations presented here are fundamental to the development of numerical models for the simulation of multiphase flow and transport processes inside landfills coupled with biochemical reactions and heat generation. The implicit modelling of leachate and gas flows including growth and decay of micro-organisms are innovative contributions to landfill modelling PMID:16941996

Kindlein, Jonatham; Dinkler, Dieter; Ahrens, Hermann

2006-08-01

300

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

Code of Federal Regulations, 2011 CFR

...0%. A3: Area with daily soil cover and active gas collection CE3: 60%. A4: Area with an intermediate soil cover, or a final soil cover not meeting the criteria for A5 below, and active gas collection CE4: 75%....

2011-07-01

301

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

Code of Federal Regulations, 2013 CFR

...0%. A3: Area with daily soil cover and active gas collection CE3: 60%. A4: Area with an intermediate soil cover, or a final soil cover not meeting the criteria for A5 below, and active gas collection CE4: 75%....

2013-07-01

302

Mill Seat Landfill Bioreactor Renewable Green Power (NY)  

SciTech Connect

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.

Barton & Loguidice, P.C.

2010-01-07

303

Instrumentation for Continuous Monitoring of Meteorological Variables and Soil Gas Pressure in Landfill Cover.  

National Technical Information Service (NTIS)

To examine changes in soil gas pressure relative to changes in atmospheric pressure and other meteorological variables, weather station sensors and electronic pressure transducers were interfaced with an RCA COSMAC microcomputer. The microcomputer control...

C. Moore M. Vogt J. Bogner

1986-01-01

304

Properties and Chemical Composition of Typical Coker Gas Oil  

Microsoft Academic Search

The coker gas oil from Daqing, Shengli, and Liaohe, which are three famous oil fields in China, are studied. The properties, chemical composition, and structural composition of coker gas oil from Daqing, Shengli, and Liaohe saturated hydrocarbon are analyzed. The results show that nitrogen and sulfur content in Daqing coker gas oil is the lowest, and saturated hydrocarbon content is

B. Hou; Z. Cao; W. Chen; J. Han

2007-01-01

305

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

PubMed

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

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

2013-08-01

306

Tunable composite membranes for gas separations  

SciTech Connect

The use of membrane technology for gas separations offers significant thermodynamic and economic advantages over distillation processes. Target separations of importance to the coal and energy fields include N{sub 2}/O{sub 2}, H{sub 2}S/syngas and CO{sub 2}/CH{sub 4}. Current strategies for improving these separations are largely directed towards processable polymers with thin (< 500 {angstrom}) skins. Unfortunately most polymeric materials that provide commercially viable permeation rates exhibit poor selectivities and vice versa and there are inherent limitations in gas permeability/permselectivity for pure polymers. The strategy relies on modification of composite membranes, preferably in situ, to enhance the permselectivity while maintaining acceptable permeabilities. The composites consist of electroactive polymers (which can be switched from rubbery to glassy), filled with selective absorbents (zeolites) which are impregnated with metals or catalysts to effect facilitated transport. The project is multifaceted and involves the efforts of a polymer synthesis group, a microporous materials group, a microscopy group and a permeability measurements group, all working in concert. This final report summarizes the results of the efforts on the project.

Ferraris, J.P.; Balkus, K.J. Jr.; Musselman, I.H.

1999-05-01

307

LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL  

SciTech Connect

''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.

Don Augenstein

1999-01-11

308

Instrumentation for continuous monitoring of meteorological variables and soil gas pressure in landfill cover  

Microsoft Academic Search

To examine changes in soil gas pressure relative to changes in atmospheric pressure and other meteorological variables, weather station sensors and electronic pressure transducers were interfaced with an RCA COSMAC microcomputer. The microcomputer control permitted simultaneous acquisition of pressure and meteorological data on cassette tape. Because the RCA unit uses CMOS circuitry, it can be battery operated, and is therefore

C. Moore; M. Vogt; J. Bogner

1986-01-01

309

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

PubMed

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 ?g 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

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

2010-05-04

310

Methane from landfills: Preliminary assessment workbook  

NASA Astrophysics Data System (ADS)

System options for developing landfill gas recovery projects are discussed. Factors effecting the economics of each option are reported. Sample calculations and worksheets are included to assist in the process of making preliminary judgments about production and revenue potentials for landfill gas recovery at a specific site.

Wilkey, M. L.; Zimmerman, R. E.; Isaacson, H. R.

1982-06-01

311

Methane oxidation in a landfill cover with capillary barrier  

Microsoft Academic Search

The methane oxidation potential of a landfill cover with capillary barrier was investigated in an experimental plant (4.8m×0.8m×2.1m). The cover soil consisted of two layers, a mixture of compost plus sand (0.3m) over a layer of loamy sand (0.9m). Four different climatic conditions (summer, winter, spring and fall) were simulated. In and outgoing fluxes were measured. Gas composition, temperature, humidity,

J. Berger; L. V. Fornés; C. Ott; J. Jager; B. Wawra; U. Zanke

2005-01-01

312

Bringing new life to old landfills  

SciTech Connect

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.

Rabasca, L.

1996-01-01

313

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

PubMed

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

Assamoi, Bernadette; Lawryshyn, Yuri

2011-11-17

314

TUNABLE COMPOSITE MEMBRANES FOR GAS SEPARATIONS  

SciTech Connect

Smooth, dense, uniformly thick membranes were solution cast from poly(3-octylthiophene) (POT) and their permeability properties were investigated for N{sub 2}, O{sub 2}, CH{sub 4}, and CO{sub 2} (P{sub N{sub 2}} = 5.8 {+-} 0.4, P{sub O{sub 2}} = 15.6 {+-} 0.8, P{sub CH{sub 4}} = 17.8 {+-} 1.4, P{sub CO{sub 2}} = 63.6 {+-} 2.2 Barrers), and selectivity properties were calculated ({alpha}{sub O{sub 2}/N{sub 2}} = 2.7 {+-} 0.2, {alpha}{sub CO{sub 2}/N{sub 2}} = 11.2 {+-} 0.8, {alpha}{sub CO{sub 2}/CH{sub 4}} = 3.6 {+-} 0.2). NaY/POT composite membranes (20, 30, and 40% w/w zeolite) were prepared by stirring the polymer into a zeolitic suspension. Facilitated transport of gases (N{sub 2}, O{sub 2}, CH{sub 4}, and CO{sub 2}) was observed for each of the zeolite loadings, the magnitude of which depended on the chemical nature of the gas and polymer/zeolite-penetrant interaction. Maximum facilitation was observed for 40% NaY/POT composite membranes (Facilitation ratio of N{sub 2} = 0.38 {+-} 0.03, O{sub 2} = 0.56 {+-} 0.02, CH{sub 4} = 0.13 {+-} 0.01, CO{sub 2} = 0.71 {+-} 0.02). An increase in the selectivity of gases was also observed for all zeolite loadings.

J.P. Ferraris; K.J. Balkus, Jr.; I.H. Musselman

1998-07-01

315

Landfill leachate treatment: Review and opportunity  

Microsoft Academic Search

In most countries, sanitary landfilling is nowadays the most common way to eliminate municipal solid wastes (MSW). In spite of many advantages, generation of heavily polluted leachates, presenting significant variations in both volumetric flow and chemical composition, constitutes a major drawback. Year after year, the recognition of landfill leachate impact on environment has forced authorities to fix more and more

S. Renou; J. G. Givaudan; S. Poulain; F. Dirassouyan; P. Moulin

2008-01-01

316

Missing Halocarbon Source? Data from a Recent New England Landfill Field Campaign  

NASA Astrophysics Data System (ADS)

Anthropogenic emissions of long-lived halocarbons, namely chlorofluorocarbons (CFCs), hydrofluorocarbons (HCFCs), methyl chloroform (CH3CCl3), and carbon tetrachloride (CCl4) represent the largest source of atmospheric chlorine. All of these gases with the exception of the HCFCs are banned under the Montreal Protocol from being produced within the US or imported into the US. Several recent studies indicate that lingering emissions of these compounds are occurring around urban areas in the US. One possible source for these emissions is leakage from landfills. Landfill emissions are not currently considered explicitly in the published industry based global estimations of emissions for these gases. Previous studies have been done in the UK and suggested that this leakage may be significant (on the order of 1 Gg/year in the UK) in comparison with industry emissions estimates, but no measurement based estimates of Montreal Protocol gas emissions from US landfills have been previously reported. To further investigate this idea, flask samples were taken during the winter of 2004 at two Eastern Massachusetts landfills and during the summer of 2004 at four landfills in southwestern Britain. These studies showed more data was needed to create clear regression relationships between the landfill parameters (waste composition, landfill age, and total trash volume) and halocarbon gas emissions of CFC-12, CFC-11, CFC-113, and CH3CCl3. In a movement towards creating the necessary database of measurements, an intensive Fall 2005 landfill measurement campaign was conducted in New England. The results from this campaign will be presented, analyzed and compared to our results from the above two 2004 investigations.

Hodson, E. L.; Prinn, R.

2005-12-01

317

ESTIMATE OF METHANE EMISSIONS FROM U.S. LANDFILLS  

EPA Science Inventory

The report describes the development of a statistical regression model used for estimating methane (CH4) emissions, which relates landfill gas (LFG) flow rates to waste-in-place data from 105 landfills with LFG recovery projects. (NOTE: CH4 flow rates from landfills with LFG reco...

318

Composition and Properties of Chinese Coker Gas Oil  

Microsoft Academic Search

The composition and properties of China coker gas oil are analyzed and studied. The factors of effecting on the reaction of coker gas oil and measures that should be adopted are discussed. Research results show that China coker gas oil contains 86.04–86.87% C and 11.96–13.72% H, with an H\\/C atom ratio of 1.7. China coker gas oil contains 51.1–68.3% of

Z. Cao; B. Hou; W. Chen; Q. Zhao

2007-01-01

319

Practice review of five bioreactor/recirculation landfills.  

PubMed

Five landfills were analyzed to provide a perspective of current practice and technical issues that differentiate bioreactor and recirculation landfills in North America from conventional landfills. The bioreactor and recirculation landfills were found to function in much the same manner as conventional landfills, with designs similar to established standards for waste containment facilities. Leachate generation rates, leachate depths and temperatures, and liner temperatures were similar for landfills operated in a bioreactor/recirculation or conventional mode. Gas production data indicate accelerated waste decomposition from leachate recirculation at one landfill. Ambiguities in gas production data precluded a definitive conclusion that leachate recirculation accelerated waste decomposition at the four other landfills. Analysis of leachate quality data showed that bioreactor and recirculation landfills generally produce stronger leachate than conventional landfills during the first two to three years of recirculation. Thereafter, leachate from conventional and bioreactor landfills is similar, at least in terms of conventional indicator variables (BOD, COD, pH). While the BOD and COD decreased, the pH remained around neutral and ammonia concentrations remained elevated. Settlement data collected from two of the landfills indicate that settlements are larger and occur much faster in landfills operated as bioreactors or with leachate recirculation. The analysis also indicated that more detailed data collection over longer time periods is needed to draw definitive conclusions regarding the effects of bioreactor and recirculation operations. For each of the sites in this study, some of the analyses were limited by sparseness or ambiguity in the data sets. PMID:16766174

Benson, C H; Barlaz, M A; Lane, D T; Rawe, J M

2006-06-12

320

Composition of coalbed gas. Report of investigations  

Microsoft Academic Search

Samples of gas were obtained directly from the coalbed during drilling ; of horizontal and vertical boreholes in six different formations. The samples ; were analyzed by gas chromatography for C to C hydrocarbons and for ; O, N, H, He, and CO. Methane in the gas varied from ; 63 to 99 percent; carbon dioxide from 0.l to 15

1973-01-01

321

Characteristics of landfill leachates and alternatives for their treatment: A review  

Microsoft Academic Search

Sanitary landfilling is the most common way to eliminate solid urban wastes. An important problem associated to landfills is the production of leachates. The factors determining the characteristics of leachates from solid urban waste landfills are reviewed together with the reported compositions of leachates from various countries and origins. New data obtained from two landfills of different age in the

J. M. Lema; R. Mendez; R. Blazquez

1988-01-01

322

Corrosion inhibition by control of gas composition during mist drilling  

SciTech Connect

Chemical compositional specifications have been generated for inert gases which reduce drill string corrosion when used in conjunction with mist drilling processes. These specifications are based on the assumption that the corrosion rate is dependent on the dissolved gaseous species concentrations. Data taken both from the literature and from a mist drilling field test with nitrogen in Valle Grande, NM, relate corrosion rates to fluid compositions. These solution compositions are then associated with gas phase compositions using equilibrium data available from the literature and material balances. Two sources of gas were considered: cryogenically purified nitrogen from air and exhaust gas from a diesel engine, which contain (in addition to N/sub 2/ and O/sub 2/) CO/sub 2/, NO/sub x/, SO/sub 2/, H/sub 2/O, and CO. A maximum concentration of 50 ppM O/sub 2/ in the gas phase is recommended to alleviate pitting corrosion.

Hinkebein, T.E.; Snyder, T.L.

1981-05-01

323

Requiem for sanitary landfills. The struggle to build a solid-waste disposal plant  

Microsoft Academic Search

Existing landfills outside of many major cities which no longer meet federal and state regulations can become sources of pollution and health hazards. Leaching of refuse at sanitary landfills threatens underground water supplies, while landfills that have been closed and covered have a tendency to produce methane gas. Until a new landfill site becomes necessary, few users understand the environmental

Palmquist

1986-01-01

324

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

PubMed

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 ?(13)C, ?(2)H and ?(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 ?(13)C-value of the dissolved inorganic carbon (?(13)C-DIC) of the leachate between aerobic and anaerobic waste material. During aerobic degradation, the signature of ?(13)C-DIC was mainly dependent on the isotopic composition of the organic matter in the waste, resulting in a ?(13)C-DIC of -20‰ to -25‰. The production of methane under anaerobic conditions caused an increase in ?(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 ?(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 stability of the organic matter in landfilled municipal solid waste and can be used for monitoring the progress of in situ aeration. PMID:23540355

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

2013-03-27

325

Prediction of light gas composition in coal devolatilization  

Microsoft Academic Search

The chemical percolation devolatilization (CPD) model describes the devolatilization behavior of rapidly heated coal based on the chemical structure of the coal. It predicts the overall char, tar, and light gas yields. This paper presents an improved CPD model with improved capability for predicting light gas composition. This is achieved by incorporating a kinetic model that simulates the release of

Ravichandra S. Jupudi; Vladimir Zamansky; Thomas H. Fletcher

2009-01-01

326

Mitigation of Landfill Methane Emissions from Passive Vents by use of Oxidizing Biofilters  

Microsoft Academic Search

Decay of waste within landfills is a contributing source to the greenhouse effect due to the production of methane. Larger landfills tend to have gas collection systems, which collect and convert gas into energy or flare it. Older and smaller landfills, however, usually vent this greenhouse gas into the atmosphere through passive vents. This study focuses on the attenuation of

Jose J. Morales

2006-01-01

327

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

SciTech Connect

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.

Assamoi, Bernadette [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5 (Canada); Lawryshyn, Yuri, E-mail: yuri.lawryshyn@utoronto.ca [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5 (Canada)

2012-05-15

328

Modelling of biogas extraction at an Italian landfill accepting mechanically and biologically treated municipal solid waste.  

PubMed

This paper presents the results of the modelling of the biogas extraction in a full-scale Italian landfill by the USEPA LandGEM model and the Andreottola-Cossu approach. The landfill chosen for this research ('Il Fossetto' plant, Monsummano Terme, Italy) had accepted mixed municipal raw waste for about 15?years. In the year 2003 a mechanical biological treatment (MBT) was implemented and starting from the end of the year 2006, the recirculation in the landfill of the concentrated leachate coming from the internal membrane leachate treatment plant was put into practice. The USEPA LandGEM model and the Andreottola-Cossu approach were chosen since they require only input data routinely acquired during landfill management (waste amount and composition) and allow a simplified calibration, therefore they are potentially useful for practical purposes such as landfill gas management. The results given by the models are compared with measured data and analysed in order to verify the impact of MBT on biogas production; moreover, the possible effects of the recirculation of the concentrated leachate are discussed. The results clearly show how both models can adequately fit measured data even after MBT implementation. Model performance was significantly reduced for the period after the beginning of recirculation of concentrated leachate when the probable inhibition of methane production, due to the competition between methanogens and sulfate-reducing bacteria, significantly influenced the biogas production and composition. PMID:21930528

Calabrò, Paolo S; Orsi, Sirio; Gentili, Emiliano; Carlo, Meoni

2011-09-18

329

Structure and Composition Analysis of Natural Gas Hydrates: 13C NMR Spectroscopic and Gas Uptake Measurements of Mixed Gas Hydrates  

Microsoft Academic Search

Gas hydrates are becoming an attractive way of storing and transporting large quantities of natural gas, although there has been little effort to understand the preferential occupation of heavy hydrocarbon molecules in hydrate cages. In this work, we present the formation kinetics of mixed hydrate based on a gas uptake measurement during hydrate formation, and how the compositions of the

Yutaek Seo; Seong-Pil Kang; Wonho Jang

2009-01-01

330

Field application of nitrogen and phenylacetylene to mitigate greenhouse gas emissions from landfill cover soils: effects on microbial community structure.  

PubMed

Landfills are large sources of CH(4), but a considerable amount of CH(4) can be removed in situ by methanotrophs if their activity can be stimulated through the addition of nitrogen. Nitrogen can, however, lead to increased N(2)O production. To examine the effects of nitrogen and a selective inhibitor on CH(4) oxidation and N(2)O production in situ, 0.5 M of NH(4)Cl and 0.25 M of KNO(3), with and without 0.01% (w/v) phenylacetylene, were applied to test plots at a landfill in Kalamazoo, MI from 2007 November to 2009 July. Nitrogen amendments stimulated N(2)O production but had no effect on CH(4) oxidation. The addition of phenylacetylene stimulated CH(4) oxidation while reducing N(2)O production. Methanotrophs possessing particulate methane monooxygenase and archaeal ammonia-oxidizers (AOAs) were abundant. The addition of nitrogen reduced methanotrophic diversity, particularly for type I methanotrophs. The simultaneous addition of phenylacetylene increased methanotrophic diversity and the presence of type I methanotrophs. Clone libraries of the archaeal amoA gene showed that the addition of nitrogen increased AOAs affiliated with Crenarchaeal group 1.1b, while they decreased with the simultaneous addition of phenylacetylene. These results suggest that the addition of phenylacetylene with nitrogen reduces N(2)O production by selectively inhibiting AOAs and/or type II methanotrophs. PMID:20809077

Im, Jeongdae; Lee, Sung-Woo; Bodrossy, Levente; Barcelona, Michael J; Semrau, Jeremy D

2010-08-31

331

Composition of Low-redshift Halo Gas  

NASA Astrophysics Data System (ADS)

Halo gas in low-z (z < 0.5) >=0.1 L * galaxies in high-resolution, large-scale cosmological hydrodynamic simulations is examined with respect to three components: cold, warm, and hot with temperatures of <105, 105-6, and >106 K, respectively. Utilizing O VI ??1032, 1038 absorption lines, the warm component is compared to observations, and agreement is found with respect to the galaxy-O VI line correlation, the ratio of the O VI line incidence rate in blue to red galaxies, and the amount of O VI mass in star-forming galaxies. A detailed account of the sources of warm halo gas (stellar feedback heating, gravitational shock heating, and accretion from the intergalactic medium), inflowing and outflowing warm halo gas metallicity disparities, and their dependencies on galaxy types and environment is also presented. With the warm component securely anchored, our simulations make the following additional predictions. First, cold gas is the primary component in inner regions with its mass comprising 50% of all gas within galactocentric radius r = (30, 150) kpc in (red, blue) galaxies. Second, at r > (30, 200) kpc in (red, blue) galaxies the hot component becomes the majority. Third, the warm component is a perpetual minority, with its contribution peaking at ~30% at r = 100-300 kpc in blue galaxies and never exceeding 5% in red galaxies. The significant amount of cold gas in low-z early-type galaxies, which was found in simulations and in agreement with recent observations (Thom et al.), is intriguing, as is the dominance of hot gas at large radii in blue galaxies.

Cen, Renyue

2013-06-01

332

Bisphenol A in hazardous waste landfill leachates.  

PubMed

The levels of bisphenol A in hazardous waste landfill leachates collected in Japan in 1996 were determined by gas chromatograph/mass spectrometer (GC/MS). Bisphenol A was found in seven of 10 sites investigated. All the hazardous waste landfills with leachates contaminated by bisphenol A were controlled. The concentrations of bisphenol A ranged from 1.3 to 17,200 microg/l with a median concentration of 269 microg/l. The source of bisphenol A in landfill leachates may be the waste plastics in waste landfill. The concentrations of bisphenol A in some samples exceeded the EC50 or LC50 levels for aquatic biota. Landfill leachates may be a significant source of bisphenol A found in the environment. PMID:11100793

Yamamoto, T; Yasuhara, A; Shiraishi, H; Nakasugi, O

2001-02-01

333

Ground penetrating radar characterization of a landfill  

NASA Astrophysics Data System (ADS)

Ground penetrating radar was investigated in an active landfill to determine if the in-situ water content could be measured. Water content is an important parameter in predicting the generation of landfill gas (LFG), an important renewable energy source. Unfortunately, predicting the quantity of LFG is difficult due to the heterogeneities present in a landfill and the lack of in-situ input parameters. GPR is a non-invasive, near-surface geophysical technique that provides high resolution images of dielectric properties in the earth's subsurface. A transmitter emits high frequency (10 - 1000 MHz) electromagnetic pulses through the subsurface, with the receiver recording the echo. Specialized software is then used to create images of the subsurface. The challenge with using GPR in landfills is the heterogeneity of the subsurface and the clay cap linear covering landfills, both affecting the transmission of the electromagnetic pulses. The use of GPR in a landfill was evaluated at the Region of Waterloo's Waste Management Centre. Measurements were completed using both the surface and the borehole approach. The results indicated that a borehole GPR can be used, with successful measurement of water content a function of borehole separation distance and frequency of the electromagnetic pulses. The developed approach was confirmed at the City of Hamilton's Glanbrook Landfill. The successful comparison of in-situ water content values to laboratory determined values at both landfills shows that GPR can be used to measure in-situ water content.

Yochim, April Theresa

334

Hybrid silica-polyimide composite membranes: gas transport properties  

Microsoft Academic Search

The gas permeability, diffusivity, and selectivity properties of gases such as He, O2, N2, CH4, and CO2 were evaluated for a series of hybrid inorganic–organic composites based on 6FDA-6FpDA and 6FDA-6FpDA-DABA polyimides and various organo-silica structures. The organo-silica domains were introduced into the polymer matrix via sol–gel reactions. The gas transport properties of these hybrid membranes were dependent on the

Chris J. Cornelius; Eva Marand

2002-01-01

335

Trace constituents in landfill gas. Task report on sampling and analysis, Final report, May 1984May 1986  

Microsoft Academic Search

The report represents the results of tasks performed for the Gas Research Institute (GRI) program entitled Evaluation of Gas Cleaning Technologies for Trace Constituent Removal. The report summarizes Tasks I-2 (Refine Existing and Develop New Technologies for Sampling and Analysis of Trace Constituents) and II-1 (Field Test Existing Gas Cleaning Technologies). Additional task reports for this GRI program are published

N. W. Flynn; B. deLappe

1988-01-01

336

Effect of Biogas Generation on Radon Emissions from Landfills Receiving Radium-Bearing Waste from Shale Gas Development  

Microsoft Academic Search

Dramatic increases in the development of oil and natural gas from shale formations will result in large quantities of drill cuttings, flowback water, and produced water. These organic-rich shale gas formations often contain elevated concentrations of naturally occurring radioactive materials (NORM), such as uranium, thorium, and radium. Production of oil and gas from these formations will also lead to the

Gary R. Walter; Roland R. Benke; David A. Pickett

2012-01-01

337

Gas turbine engine and composite parts  

SciTech Connect

This patent describes a gas turbine engine core engine component selected from blades, vanes, discs, side plates, seals, combustor liners, flaps, burner case structures or turbine case structures. The engine component comprises substantially titanium-free ceramic layers selected from (a) aluminosilicate, (b) lithium aluminosilicate, (c) magnesium aluminosilicate, or (d) mixtures thereof. Each layer is reinforced with unidirectional, continuous length silicon carbide fibers. Each layer has an axial flexural strength exemplified by a critical stress intensity factor greater than 10X10/sup 3/ psi (inch)/sup l/2/, high temperature strength, high temperature oxidation stability, and good insulating properties.

Prewo, K.M.; Brennan, J.J.

1986-12-02

338

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

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.

Michalzik, B. [Institute of Geography, Georg-August University Goettingen, Unit of Landscape Ecology, Goldschmidtstrasse 5, 37073 Goettingen (Germany)], E-mail: bmichal@gwdg.de; Ilgen, G.; Hertel, F. [Bayreuth Institute of Terrestrial Ecosystem Research (BITOEK/BayCEER), Central Laboratory Unit, University of Bayreuth, Dr. Hans- Frisch-Strasse 1-3, 95448 Bayreuth (Germany); Hantsch, S.; Bilitewski, B. [Institute for Waste Management and Contaminated Site Treatment, Dresden University of Technology, Pratzschwitzer Strasse 15, 01796 Pirna (Germany)

2007-07-01

339

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

SciTech Connect

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.

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

1998-02-25

340

Development of an empirical model of methane emissions from landfills. Final report Mar-Dec 91  

SciTech Connect

The report gives results of a field study of 21 U.S. landfills with gas recovery systems, to gather information that can be used to develop an empirical model of methane (CH4) emissions. Site-specific information includes average CH4 recovery rate, landfill size, tons of refuse (refuse mass), average age of the refuse, and climate. A correlation analysis showed that refuse mass was positively linearly correlated with landfill depth, volume, area, and well depth. Regression of the CH4 recovery rate on depth, refuse mass, and volume was significant, but depth was the best predictive variable (R2 = 0.53). Refuse mass was nearly as good (R2 = 0.50). None of the climate variables (precipitation, average temperature, dewpoint) were correlated with the CH4 recovery rate or with CH4 recovery per metric ton of refuse. Much of the variability in CH4 recovery remains unexplained, and is likely due to between-site differences in landfill construction, operation, and refuse composition. A model for global landfill emissions estimation is proposed.

Peer, R.L.; Epperson, D.L.; Campbell, D.L.; von Brook, P.

1992-03-01

341

Landfills in New York City: 1844--1994  

SciTech Connect

Historic topographic maps are reviewed to locate landfills constructed within New York City during four time intervals between 1844 and 1994. A total of 184.75 km{sup 2} (45,650 acres) of landfill are identified (approximately 20% of the study area). Data are not available to determine the fill composition at most sites but literature sources indicate that municipal solid waste (MSW) has been an important source of fill since at least 1891. Qualitative temporal trends in the spatial distribution of landfills and the composition and thickness of MSW landfills are observed. The oldest landfills are clustered in the vicinity of the early urban center (southern New York County) but expand in spatial distribution after the turn of this century. Logs of borings through 10 MSW landfills show that waste landfills built prior to the mid-1950s contain abundant ash (coal ash is common in the oldest landfills) and are relatively thin (3--7 m) with no topographic mounding. In MSW landfills built since that time, uncombusted organic matter is abundant, thicknesses increase greatly (16--27 m), and pronounced topographic mounding is observed. Most landfills identified in this study were built on tidal wetlands. Fine-grained wetland deposits underlying the landfills and close proximity to large surface-water bodies favor lateral transport of leachate from MSW landfills in shallow ground water and local discharge to surface water. The wide distribution of historic landfills and common use of MSW for fill indicates that these sites should be considered in investigations of ground water, surface water, and sediment quality in New York City and other urban areas where extensive historic landfilling has occurred.

Walsh, D.C. [NYSDEC, Long Island City, NY (United States); LaFleur, R.G. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Earth and Environmental Sciences

1995-07-01

342

Ceramic matrix composites application in automotive gas turbines  

Microsoft Academic Search

The authors are conducting the development of ceramic matrix composites (CMC) and components made of CMC for a 100 kW automotive ceramic gas turbine (CGT). When compared to monolithic ceramics (MC), CMC that they have developed demonstrate superior strength characteristics in terms of resistance to particle impact and thermal shock. The authors have conducted evaluation tests on the strength of

Takao Izumi; Hiroshi Kaya

1997-01-01

343

TUNABLE COMPOSITE MEMBRANES FOR GAS SEPARATIONS  

SciTech Connect

Poly 2-(3-thienyl)ethylacetate (PAET) was synthesized and solution cast as thin films to form dense membranes. These membranes are mechanically robust and are redox active, holding out promise as gas separation materials. The permeability properties of PAET membranes were evaluated for N{sub 2} (0.048 {+-} 0.008 Barrers), O{sub 2} (0.24 {+-} 0.02 Barrers), CH{sub 4} (0.081 {+-} 0.005 Barrers), and CO{sub 2} (1.4 {+-} 0.1 Barrers). The corresponding selectivity values ({alpha}) were: O{sub 2}/N{sub 2} = 5.1, CO{sub 2}/N{sub 2} = 29, and CO{sub 2}/CH{sub 4} = 18.

J.P. Ferraris; K.J. Balkus, Jr.; I.H. Musselman

1999-01-01

344

Bisphenol A in hazardous waste landfill leachates  

Microsoft Academic Search

The levels of bisphenol A in hazardous waste landfill leachates collected in Japan in 1996 were determined by gas chromatograph\\/mass spectrometer (GC\\/MS). Bisphenol A was found in seven of 10 sites investigated. All the hazardous waste landfills with leachates contaminated by bisphenol A were controlled. The concentrations of bisphenol A ranged from 1.3 to 17,200 ?g\\/l with a median concentration

Takashi Yamamoto; Akio Yasuhara; Hiroaki Shiraishi; Osami Nakasugi

2001-01-01

345

Methane Oxidation in Landfill Cover Soil  

Microsoft Academic Search

Methane oxidation in the cover soil of the Khmet'evo municipal landfill in Moscow oblast was investigated. Methane emission from the experimental site of the landfill was highly heterogeneous. At a depth of 45–60 cm, the pore gas mainly consisted of CH4 (60–70%) and CO2 (30–40%). In the upper layers of the cover soil, the concentration of these gases sharply decreased.

A. Yu. Kallistova; M. V. Kevbrina; V. K. Nekrasova; M. V. Glagolev; M. I. Serebryanaya; A. N. Nozhevnikova

2005-01-01

346

Learning from Landfills.  

ERIC Educational Resources Information Center

|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)|

Galus, Pamela

2000-01-01

347

Effects of shielding gas compositions on arc plasma and metal transfer in gas metal arc welding  

NASA Astrophysics Data System (ADS)

This article presents the effects of shielding gas compositions on the transient transport phenomena, including the distributions of temperature, flow velocity, current density, and electromagnetic force in the arc and the metal, and arc pressure in gas metal arc welding of mild steel at a constant current input. The shielding gas considered includes pure argon, 75% Ar, 50% Ar, and 25% Ar with the balance of helium. It is found that the shielding gas composition has significant influences on the arc characteristics; droplet formation, detachment, transfer, and impingement onto the workpiece; and weld pool dynamics and weld bead profile. As helium increases in the shielding gas, the droplet size increases but the droplet detachment frequency decreases. For helium-rich gases, the current converges at the workpiece with a ``ring'' shape which produces non-Gaussian-like distributions of arc pressure and temperature along the workpiece surface. Detailed explanations to the physics of the very complex but interesting transport phenomena are given.

Rao, Z. H.; Liao, S. M.; Tsai, H. L.

2010-02-01

348

The carbon isotopic composition of catalytic gas: A comparative analysis with natural gas  

SciTech Connect

Tee idea that natural gas is the thermal product of organic decomposition has persisted for over half a century. Crude oil is thought to be an important source of gas, cracking to wet gas above 150 C, and dry gas above 200 C. But there is little evidence to support this view. For example, crude oil is proving to be more stable than previously thought and projected to remain intact over geologic time at typical reservoir temperature. Moreover, when oil does crack, the products do not resemble natural gas. Oil to gas could be catalytic, however, promoted by the transition metals in carbonaceous sediments. This would explain the low temperatures at which natural gas forms, and the high amounts of methane. This idea gained support recently when the natural progression of oil to dry gas was duplicated in the laboratory catalytically. The authors report here the isotopic composition of catalytic gas generated from crude oil and pure hydrocarbons between 150 and 200 C. {delta}{sup 13}C for C{sub 1} through C{sub 5} was linear with 1/n (n = carbon number) in accordance with theory and typically seen in natural gases. Over extended reaction, isobutane and isopentane remained lighter than their respective normal isomers and the isotopic differentials were constant as all isomers became heavier over time. Catalytic methane, initially {minus}51.87{per_thousand} (oil = {minus}22.5{per_thousand}), progressed to a final composition of {minus}26.94{per_thousand}, similar to the maturity trend seen in natural gases: {minus}50{per_thousand} to {minus}20{per_thousand}. Catalytic gas is thus identical to natural gas in molecular and isotopic composition adding further support to the view that catalysis by transition metals may be a significant source of natural gas.

Mango, F.D. [Rice Univ., Houston, TX (United States). Dept. of Chemical Engineering; Elrod, L.W. [Houston Advanced Research Center, The Woodlands, TX (United States). Geotechnology Research Inst.

1999-04-01

349

The carbon isotopic composition of catalytic gas: A comparative analysis with natural gas  

NASA Astrophysics Data System (ADS)

The idea that natural gas is the thermal product of organic decomposition has persisted for over half a century. Crude oil is thought to be an important source of gas, cracking to wet gas above 150°C, and dry gas above 200°C. But there is little evidence to support this view. For example, crude oil is proving to be more stable than previously thought and projected to remain intact over geologic time at typical reservoir temperatures. Moreover, when oil does crack, the products do not resemble natural gas. Oil to gas could be catalytic, however, promoted by the transition metals in carbonaceous sediments. This would explain the low temperatures at which natural gas forms, and the high amounts of methane. This idea gained support recently when the natural progression of oil to dry gas was duplicated in the laboratory catalytically. We report here the isotopic composition of catalytic gas generated from crude oil and pure hydrocarbons between 150 and 200°C. ? 13C for C 1 through C 5 was linear with 1/ n ( n = carbon number) in accordance with theory and typically seen in natural gases. Over extended reaction, isobutane and isopentane remained lighter than their respective normal isomers and the isotopic differentials were constant as all isomers became heavier over time. Catalytic methane, initially -51.87‰ (oil = -22.5‰), progressed to a final composition of -26.94‰, similar to the maturity trend seen in natural gases: -50‰ to -20‰. Catalytic gas is thus identical to natural gas in molecular and isotopic composition adding further support to the view that catalysis by transition metals may be a significant source of natural gas.

Mango, Frank D.; Elrod, L. W.

1999-04-01

350

System for controlling the composition of a fuel gas produced by a jet compressor system  

SciTech Connect

A method of providing a mixture of lean and rich gas of a desired composition by means of a jet compressor system comprising two or more jet compressors comprising: adjusting the jet compressor system being used to mix the lean and rich gas to provide a leaner gas mixture than the desired composition; then adding a predetermined amount of rich gas to the leaner gas mixture to attempt to obtain the desired composition; and varying the amount of rich gas added to the leaner gas in response to the measurement of gas properties in the jet compressor system to thereby more nearly obtain a gas of the desired composition. Preferably the lean gas comprises air, blast furnace gas, or BOF gas, and the rich gas comprises methane, natural gas, propane, or butane.

Boggs, W. E.; Keener, E. L.

1985-08-20

351

Gas phase composition effects on suspension cultures of Taxus cuspidata  

SciTech Connect

The effect of different concentrations and combinations of oxygen, carbon dioxide, and ethylene on cell growth and taxol production in suspension cultures of Taxus cuspidata was investigated using several factorial design experiments. Low head space oxygen concentration (10% v/v) promoted early production of taxol. High carbon dioxide concentration (10% v/v) inhibited taxol production.The most effective gas mixture composition in terms of taxol production was 10% (v/v) oxygen, 0.5% (v/v) carbon dioxide, and 5 ppm ethylene. Cultures grown under ambient concentration of oxygen had a delayed uptake of glucose and fructose compared to cultures grown under 10% (v/v) oxygen. Average calcium uptake rates into the cultured cells decreased and average phosphate uptake rates increased as ethylene was increased from 0 to 10 ppm. These results may indicate that gas composition alters partitioning of nutrients, which in turn affects secondary metabolite production.

Mirjalili, N.; Linden, J.C. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemical and Bioresources Engineering

1995-10-20

352

Environmental applications using graphene composites: water remediation and gas adsorption.  

PubMed

This review deals with wide-ranging environmental studies of graphene-based materials on the adsorption of hazardous materials and photocatalytic degradation of pollutants for water remediation and the physisorption, chemisorption, reactive adsorption, and separation for gas storage. The environmental and biological toxicity of graphene, which is an important issue if graphene composites are to be applied in environmental remediation, is also addressed. PMID:23487161

Kemp, K Christian; Seema, Humaira; Saleh, Muhammad; Le, Nhien H; Mahesh, Kandula; Chandra, Vimlesh; Kim, Kwang S

2013-03-14

353

Rare gas isotopic compositions in natural gases of Japan  

Microsoft Academic Search

Isotopic and elemental compositions of rare gases in various types of gas samples collected in the Japanese Islands were investigated. Excess 3He was found in most samples. Many samples showed a regionally uniform high 3He\\/4He ratio of about 7 times the atmospheric ratio. The He concentrations varied from 0.6 to 1800 ppm, and they were low in CO2-rich gases and

Keisuke Nagao; Nobuo Takaoka; Osamu Matsubayashi

1981-01-01

354

Gas Composition Transients in the Cold Vacuum Drying (CVD) Facility  

SciTech Connect

The purpose of this document is to evaluate selected problems involving the prediction of transient gas compositions during Cold Vacuum Drying operations. The problems were evaluated to answer specific design questions. The document is formatted as a topical report with each section representing a specific problem solution. The problem solutions are reported in the calculation format specified in HNF-1613, Rev. 0, EP 7.6.

PACKER, M.J.

2000-05-10

355

Gas phase composition effects on suspension cultures of Taxus cuspidata  

Microsoft Academic Search

The effect of different concentrations and combinations of oxygen, carbon dioxide, and ethylene on cell growth and taxol production in suspension cultures of Taxus cuspidata was investigated using several factorial design experiments. Low head space oxygen concentration (10% v\\/v) promoted early production of taxol. High carbon dioxide concentration (10% v\\/v) inhibited taxol production.The most effective gas mixture composition in terms

Noushin Mirjalili; James C. Linden

1995-01-01

356

Melt Infiltrated Ceramic Composites (Hipercomp) for Gas Turbine Engine Applications  

SciTech Connect

This report covers work performed under the Continuous Fiber Ceramic Composites (CFCC) program by GE Global Research and its partners from 1994 through 2005. The processing of prepreg-derived, melt infiltrated (MI) composite systems based on monofilament and multifilament tow SiC fibers is described. Extensive mechanical and environmental exposure characterizations were performed on these systems, as well as on competing Ceramic Matrix Composite (CMC) systems. Although current monofilament SiC fibers have inherent oxidative stability limitations due to their carbon surface coatings, the MI CMC system based on multifilament tow (Hi-Nicalon ) proved to have excellent mechanical, thermal and time-dependent properties. The materials database generated from the material testing was used to design turbine hot gas path components, namely the shroud and combustor liner, utilizing the CMC materials. The feasibility of using such MI CMC materials in gas turbine engines was demonstrated via combustion rig testing of turbine shrouds and combustor liners, and through field engine tests of shrouds in a 2MW engine for >1000 hours. A unique combustion test facility was also developed that allowed coupons of the CMC materials to be exposed to high-pressure, high-velocity combustion gas environments for times up to {approx}4000 hours.

Gregory Corman; Krishan Luthra

2005-09-30

357

Stabilized landfill leachate treatment by combined physicochemical–nanofiltration processes  

Microsoft Academic Search

Landfill leachate is a complex wastewater which the composition and concentration of contaminants are influenced by the type of waste deposited and the age of landfill. In the last years, several processes or process combinations were developed and tested to reach requirements for the discharge of leachate. Among the new processes, membrane processes are considered as promising: reverse osmosis is

D Trebouet; J. P Schlumpf; P Jaouen; F Quemeneur

2001-01-01

358

Acid gas scrubbing by composite solvent-swollen membranes  

DOEpatents

A composite immobilized liquid membrane suitable for acid gas scrubbing is disclosed. The membrane is a solvent-swollen polymer and a microporous polymeric support, the solvent being selected from a class of highly polar solvents containing at least one atom selected from nitrogen, oxygen, phosphorous and sulfur, and having a boiling point of at least 100.degree. C. and a solubility parameter of from about 7.5 to about 13.5 (cal/cm.sup.3 -atm).sup.1/2. Such solvents are homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. Also disclosed are methods of acid gas scrubbing of high- and low-Btu gas effluents with such solvent-swollen membranes.

Matson, Stephen L. (Harvard, MA); Lee, Eric K. L. (Acton, MA); Friesen, Dwayne T. (Bend, OR); Kelly, Donald J. (Bend, OR)

1988-01-01

359

Acid gas scrubbing by composite solvent-swollen membranes  

DOEpatents

A composite immobilized liquid membrane suitable for acid gas scrubbing is disclosed. The membrane is a solvent-swollen polymer and a microporous polymeric support, the solvent being selected from a class of highly polar solvents containing at least one atom selected from nitrogen, oxygen, phosphorus and sulfur, and having a boiling point of at least 100 C and a solubility parameter of from about 7.5 to about 13.5 (cal/cm[sup 3]-atm)[sup 1/2]. Such solvents are homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. Also disclosed are methods of acid gas scrubbing of high- and low-Btu gas effluents with such solvent-swollen membranes. 3 figs.

Matson, S.L.; Lee, E.K.L.; Friesen, D.T.; Kelly, D.J.

1988-04-12

360

An assessment of bioreactor landfill costs and benefits.  

PubMed

Because effective operation of bioreactor landfills involves careful operation and construction of infrastructure beyond that necessary in traditional landfills, upfront capital and operating costs are greater than those associated with traditional landfills. Prior to investing in bioreactor landfills, landfill owners must be convinced that larger short-term expenses (e.g., liquid and/or air injection infrastructure) will be balanced by future economic benefits (e.g., extension of landfill life, reduced leachate treatment costs, etc.). The purpose of this paper is to describe an economic model developed to evaluate the impact of various operational (anaerobic, aerobic, or hybrid) and construction (retrofit and as-built) bioreactor landfill strategies on project economics. Model results indicate retrofit bioreactor landfills are more expensive than traditional landfills, while both the as-built and aerobic bioreactor landfills are less costly. Simulation results indicate the parameters that influence bioreactor economics most significantly are airspace recovery, gas recovery and subsequent use to generate electricity, and savings resulting from reduced leachate treatment costs. PMID:19167875

Berge, Nicole D; Reinhart, Debra R; Batarseh, Eyad S

2009-01-23

361

Bioassays for the Evaluation of Landfill Leachate Toxicity  

Microsoft Academic Search

This article reviews the application of bioassays for assessing the toxicity hazard posed by landfill leachate discharged to an aquatic environment. Landfill leachate is a complex mixture of chemicals; thus it is difficult to assess the risk posed to aquatic wildlife using standard chemical identification techniques, such as gas chromatography–mass spectroscopy (GC-MS). From this review it is clear that toxicity

David John Lawrence Thomas; Sean Ferguson Tyrrel; Richard Smith; Steve Farrow

2009-01-01

362

Comparison of slope stability in two Brazilian municipal landfills  

Microsoft Academic Search

The implementation of landfill gas to energy (LFGTE) projects has greatly assisted in reducing the greenhouse gases and air pollutants, leading to an improved local air quality and reduced health risks. The majority of cities in developing countries still dispose of their municipal waste in uncontrolled ‘open dumps.’ Municipal solid waste landfill construction practices and operating procedures in these countries

B. Gharabaghi; M. K. Singh; C. Inkratas; I. R. Fleming; E. McBean

2008-01-01

363

Methane oxidation in simulated landfill cover soil environments  

Microsoft Academic Search

Methane is an important greenhouse gas. Its contribution to the enhanced global warming is estimated at 12%. A considerable fraction of the methane that is produced by landfills is oxidized by its covering soil before it can reach the atmosphere. This process was studied in soil columns that simulate landfill cover soil environments. The methane uptake was followed as a

Alex De Visscher; Dirk Thomas; Pascal Boeckx; Oswald Van Cleemput

1999-01-01

364

Quantifying the effect of oxidation on landfill methane emissions  

Microsoft Academic Search

Field, laboratory, and computer modeling methods were utilized to quantitatively assess the capability of aerobic microorganisms to oxidize landfill-derived methane (CH4) in cover soils. The investigated municipal landfill, located in Nashua, New Hampshire, was operating without gas controls of any type at the time of sample collection. Soil samples from locations of CH 4 flux to the atmosphere were returned

P. M. Czepiel; B. Mosher; P. M. Crill; R. C. Harriss

1996-01-01

365

AP-42 ADDITIONS AND REVISIONS - LANDFILLS (COMBUSTION CONTROLS)  

EPA Science Inventory

This project develops emission factors, etc., for landfills, in particular for combustion devices fed by landfill gas, for incorporation into AP-42. AP-42 is a massive collection of information concerning processes which generate air emissions and presents emission factors and co...

366

Accelerated landfill waste decomposition by external leachate recirculation from an old landfill cell.  

PubMed

This research is focused on the management of moisture regime for a young landfill site in terms of leachate recirculation which entails the containment, collection and reinjection of leachate back into the landfill to promote in situ anaerobic biological treatment. Moreover, an innovative leachate management strategy was developed by using leachate recirculation from a mature landfill site into a young landfill site to provide accelerated waste stabilization. For this purpose, two reactors simulating young and old landfills were used in the laboratory. These reactors were loaded with shredded and compacted municipal solid waste with a typical composition determined for Istanbul Region. Both reactors were operated in a constant temperature room at 32 degrees C to enhance the growth of anaerobic microorganisms. Moreover, water was added to the reactors in order to simulate the annual rainfall. The reactor having the properties of old landfills was used as a control reactor. The reactor which represented the characteristics of young landfill was operated under four operational stages to enhance the activity of methanogenic population and accelerate waste stabilization. Results of this study indicated that the utilization of leachate recirculation enhanced waste stabilization in the young landfill by increasing the uniformity, and providing additional substrate and nutrients. Additions of buffer solutions of KOH and Na2CO3 together with leachate recirculation enhanced further waste stabilization and prevented possible acid inhibition. The utilization of external leachate recycled from the old landfill having desired acclimated anaerobic microorganisms, low organic content and higher buffer capacity into a young landfill could be a promising leachate management strategy for faster and controlled waste stabilization. PMID:12926691

Suna Erses, A; Onay, T T

2003-01-01

367

T2LBM Version 1.0: Landfill bioreactor model for TOUGH2  

Microsoft Academic Search

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

Curtis M

2001-01-01

368

Wet landfill decomposition rate determination using methane yield results for excavated waste samples.  

PubMed

An increasing number of landfills are operated to accelerate waste decomposition through liquids addition (e.g., leachate recirculation) as a wet landfill. Landfill design and regulation often depend on utilizing landfill gas production models that require an estimate of a first-order gas generation rate constant, k. Consequently, several studies have estimated k using collected gas volumes from operating wet landfills. Research was conducted to examine an alternative approach in which k is estimated not from collected landfill gas but from solid waste samples collected over time and analyzed for remaining gas yield. To achieve this goal, waste samples were collected from 1990 through 2007 at two full-scale landfills in Florida that practiced liquids addition. Methane yields were measured from waste samples collected over time, including periods before and after leachate recirculation, and the results were applied to a first-order decay model to estimate rate constants for each of the sites. An initial, intensive processing step was conducted to exclude non-biodegradable components from the methane yield testing procedure. The resulting rate constants for the two landfills examined were 0.47 yr(-1) and 0.21 yr(-1). These results expectedly exceeded the United States Environmental Protection Agency's rate constants for dry and conventional landfills (0.02-0.05 yr(-1)), but they are comparable to wet landfill rate constants derived using landfill gas data (0.1-0.3 yr(-1)). PMID:22516100

Kim, Hwidong; Townsend, Timothy G

2012-04-17

369

Report: management problems of solid waste landfills in Kuwait.  

PubMed

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. PMID:12363092

Al-Yaqout, Anwar F; Hamoda, Mohamed F

2002-08-01

370

Effects of Gas Composition and Geothermal Properties on the Thickness and Depth of Natural-Gas-Hydrate Zones  

Microsoft Academic Search

When natural gas and water contact at low temperature and high pressure, gas hydrates can form. In colder climates (such as Alaska, Northern Canada, and Siberia) and beneath the oceans, conditions are appropriate for gas-hydrate formation. This paper gives the depths and potential thicknesses of such hydrate formations as a function of the geothermal gradient, gas composition, and where appropriate,

G. D. Holder; R. D. Malone; W. F. Lawson

1987-01-01

371

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

SciTech Connect

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.

Bogner, J.; Spokas, K. [Argonne National Lab., IL (United States); Niemann, M.; Niemann, L. [Rust Environment and Infrastructure, Oak Brook, IL (United States); Baker, J. [WMX Technology Center, Geneva, IL (United States)

1997-08-01

372

Landfill disposal systems  

PubMed Central

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 inspections and any repairs can be made without disturbing the waste. The surface seal landfill does not employ a subsurface barrier. The surface seal landfill successfully addresses each of the four environmental problems listed above, provided that this landfill design is utilized for dry wastes only and is located at a site which provides protection from groundwater and temporary perched water tables. ImagesFIGURE 3.FIGURE 4.FIGURE 7.FIGURE 7.

Slimak, Karen M.

1978-01-01

373

Landfill disposal systems.  

PubMed

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 inspections and any repairs can be made without disturbing the waste. The surface seal landfill does not employ a subsurface barrier. The surface seal landfill successfully addresses each of the four environmental problems listed above, provided that this landfill design is utilized for dry wastes only and is located at a site which provides protection from groundwater and temporary perched water tables. PMID:738247

Slimak, K M

1978-12-01

374

Aerobic landfill bioreactor  

SciTech Connect

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.

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

2000-02-15

375

Effects of natural gas composition on ignition delay under diesel conditions  

Microsoft Academic Search

Effects of variations in natural gas composition on autoignition of natural gas under direct-injection (DI) diesel engine conditions were studied experimentally in a constant-volume combustion vessel and computationally using a chemical kinetic model. Four fuel blends were investigated: pure methane, a capacity weighted mean natural gas, a high ethane content natural gas, and a natural gas with added propane typical

J. D. Naber; D. L. Siebers; S. S. Dijulio; C. K. Westbrook

1993-01-01

376

Estimation of waste component-specific landfill decay rates using laboratory-scale decomposition data.  

PubMed

The current methane generation model used by the U.S. EPA (Landfill Gas Emissions Model) treats municipal solid waste (MSW) as a homogeneous waste with one decay rate. However, component-specific decay rates are required to evaluate the effects of changes in waste composition on methane generation. Laboratory-scale rate constants, k(lab), for the major biodegradable MSW components were used to derive field-scale decay rates (k(field)) for each waste component using the assumption that the average of the field-scale decay rates for each waste component, weighted by its composition, is equal to the bulk MSW decay rate. For an assumed bulk MSW decay rate of 0.04 yr(-1), k(field) was estimated to be 0.298, 0.171, 0.015, 0.144, 0.033, 0.02, 0.122, and 0.029 yr(-1), for grass, leaves, branches, food waste, newsprint, corrugated containers, coated paper, and office paper, respectively. The effect of landfill waste diversion programs on methane production was explored to illustrate the use of component-specific decay rates. One hundred percent diversion of yard waste and food waste reduced the year 20 methane production rate by 45%. When a landfill gas collection schedule was introduced, collectable methane was most influenced by food waste diversion at years 10 and 20 and paper diversion at year 40. PMID:20496890

De la Cruz, Florentino B; Barlaz, Morton A

2010-06-15

377

Gas separation by composite solvent-swollen membranes  

DOEpatents

There is disclosed a composite immobilized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorus or sulfur atom, and having a boiling point of at least 100 C and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation. 3 figs.

Matson, S.L.; Lee, E.K.L.; Friesen, D.T.; Kelly, D.J.

1989-04-25

378

Gas separation by composite solvent-swollen membranes  

DOEpatents

There is disclosed a composite immobulized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorous or sulfur atom, and having a boiling point of at least 100.degree. C. and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation.

Matson, Stephen L. (Harvard, MA); Lee, Eric K. L. (Acton, MA); Friesen, Dwayne T. (Bend, OR); Kelly, Donald J. (Bend, OR)

1989-01-01

379

LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL  

SciTech Connect

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 landfills. This is the highest methane recovery rate per unit waste, and thus progress toward stabilization, documented anywhere for such a large waste mass. This high recovery rate is attributed to moisture, and elevated temperature attained inexpensively during startup. Economic analyses performed under Phase I of this NETL contract indicate ''greenhouse cost effectiveness'' to be excellent. Other benefits include substantial waste volume loss (over 30%) which translates to extended landfill life. Other environmental benefits include rapidly improved quality and stabilization (lowered pollutant levels) in liquid leachate which drains from the waste.

Don Augenstein; Ramin Yazdani; Rick Moore; Michelle Byars; Jeff Kieffer; Professor Morton Barlaz; Rinav Mehta

2000-02-26

380

Assessment of the methane oxidation capacity of compacted soils intended for use as landfill cover materials  

SciTech Connect

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 and diffusive ingress of atmospheric air. For one material with elevated levels of fine particles and high organic matter content, methane production impeded the quantification of methane oxidation potentials. Regarding the design of landfill cover layers it was concluded that the magnitude of the expected methane load, the texture and expected compaction of the cover material are key variables that need to be known. Based on these, a column study can serve as an appropriate testing system to determine the methane oxidation capacity of a soil intended as landfill cover material.

Rachor, Ingke, E-mail: i.rachor@ifb.uni-hamburg.de [University of Hamburg, Institute of Soil Science, Allende-Platz 2, 20146 Hamburg (Germany); Gebert, Julia; Groengroeft, Alexander; Pfeiffer, Eva-Maria [University of Hamburg, Institute of Soil Science, Allende-Platz 2, 20146 Hamburg (Germany)

2011-05-15

381

Assessment of the methane oxidation capacity of compacted soils intended for use as landfill cover materials.  

PubMed

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(-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 100g CH(4)m(-2)d(-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(4)m(-2)d(-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 and diffusive ingress of atmospheric air. For one material with elevated levels of fine particles and high organic matter content, methane production impeded the quantification of methane oxidation potentials. Regarding the design of landfill cover layers it was concluded that the magnitude of the expected methane load, the texture and expected compaction of the cover material are key variables that need to be known. Based on these, a column study can serve as an appropriate testing system to determine the methane oxidation capacity of a soil intended as landfill cover material. PMID:21067907

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

2010-11-09

382

Isotope composition (C, H, O) and gas potential assessment in the South Caspian depression (Azerbaijan)  

Microsoft Academic Search

The large amount of HC isotope composition material of over 330 samples allows to study gas potential assessment within the South Caspian depression. Maps of isotope composition changes according to area extent, as well as graphs of HC distribution depending upon stratigraphic age including rocks, graphs of isotope composition change on sampling depth were compiled for HC study and oil-gas

A. V. Poletayev

2009-01-01

383

Simplified Sanitary Landfill Design.  

National Technical Information Service (NTIS)

This report surveys and summarizes state-of-the-art practices in the design and operation of sanitary landfills. This information is intended to be used as guidelines for Facilities Engineers at Army installations. All aspects of sanitary landfills are co...

G. L. Gerdes B. A. Donahue

1979-01-01

384

Non-Controlled Emission of Light Hydrocarbons (C2-C6) to the Atmosphere From Arico's Landfill, Tenerife, Canary Islands, Spain  

Microsoft Academic Search

Light hydrocarbons play a significant role in the atmospheric chemistry because some of them act as precursors of photochemical smog production. Landfill gas is constituted by a large number of hydrocarbons and their oxidation products, as well as others organic compounds. In order to control the migration and emission of landfill gas through the landfill surface and adjacent rock, gas

S. Dionis; Y. Bernardos; C. Estevez; R. Lima; J. Salazar; P. Hernandez; N. Perez

2001-01-01

385

Bioreactor Landfill Demonstration Project  

NSDL National Science Digital Library

Managed by the Florida Center for Solid and Hazardous Waste Management, this Website provides information on the Bioreactor Landfill Demonstration Project. The slow decomposition rates in current municipal landfills have prompted research in bioreactor landfills, which operate under the "wet cell" theory where moisture is added to enhance degradation. The Research section contains a plethora of material, including the Bioreactor Presentation, which consists of 60 slides outlining the project and solid waste issues, and A Proposed Bioreactor Landfill Demonstration Project, which is the proposal that started the project. The proposal is a great source of background information about bioreactor landfills. Though not all of the topics listed on the site have active links, the information available is worthwhile.

386

Reducing Open Cell Landfill Methane Emissions with a Bioactive Alternative Daily  

SciTech Connect

Methane and carbon dioxide are formed in landfills as wastes degrade. Molecule-for-molecule, methane is about 20 times more potent than carbon dioxide at trapping heat in the earth's atmosphere, and thus, it is the methane emissions from landfills that are scrutinized. For example, if emissions composed of 60% methane and 40% carbon dioxide were changed to a mix that was 40% methane and 60% carbon dioxide, a 30% reduction in the landfill's global warming potential would result. A 10% methane, 90% carbon dioxide ratio will result in a 75% reduction in global warming potential compared to the baseline. Gas collection from a closed landfill can reduce emissions, and it is sometimes combined with a biocover, an engineered system where methane oxidizing bacteria living in a medium such as compost, convert landfill methane to carbon dioxide and water. Although methane oxidizing bacteria merely convert one greenhouse gas (methane) to another (carbon dioxide), this conversion can offer significant reductions in the overall greenhouse gas contribution, or global warming potential, associated with the landfill. What has not been addressed to date is the fact that methane can also escape from a landfill when the active cell is being filled with waste. Federal regulations require that newly deposited solid waste to be covered daily with a 6 in layer of soil or an alternative daily cover (ADC), such as a canvas tarp. The aim of this study was to assess the feasibility of immobilizing methane oxidizing bacteria into a tarp-like matrix that could be used for alternative daily cover at open landfill cells to prevent methane emissions. A unique method of isolating methanotrophs from landfill cover soil was used to create a liquid culture of mixed methanotrophs. A variety of prospective immobilization techniques were used to affix the bacteria in a tarp-like matrix. Both gel encapsulation of methanotrophs and gels with liquid cores containing methanotrophs were readily made but prone to rapid desiccation. Bacterial adsorption onto foam padding, natural sponge, and geotextile was successful. The most important factor for success appeared to be water holding capacity. Prototype biotarps made with geotextiles plus adsorbed methane oxidizing bacteria were tested for their responses to temperature, intermittent starvation, and washing (to simulate rainfall). The prototypes were mesophilic, and methane oxidation activity remained strong after one cycle of starvation but then declined with repeated cycles. Many of the cells detached with vigorous washing, but at least 30% appeared resistant to sloughing. While laboratory landfill simulations showed that four-layer composite biotarps made with two different types of geotextile could remove up to 50% of influent methane introduced at a flux rate of 22 g m{sup -2} d{sup -1}, field experiments did not yield high activity levels. Tests revealed that there were high hour-to-hour flux variations in the field, which, together with frequent rainfall events, confounded the field testing. Overall, the findings suggest that a methanotroph embedded biotarp appears to be a feasible strategy to mitigate methane emission from landfill cells, although the performance of field-tested biotarps was not robust here. Tarps will likely be best suited for spring and summer use, although the methane oxidizer population may be able to shift and adapt to lower temperatures. The starvation cycling of the tarp may require the capacity for intermittent reinoculation of the cells, although it is also possible that a subpopulation will adapt to the cycling and become dominant. Rainfall is not expected to be a major factor, because a baseline biofilm will be present to repopulate the tarp. If strong performance can be achieved and documented, the biotarp concept could be extended to include interception of other compounds beyond methane, such as volatile aromatic hydrocarbons and chlorinated solvents.

Helene Hilger; James Oliver; Jean Bogner; David Jones

2009-03-31

387

Attenuation of landfill leachate pollutants in aquifers  

Microsoft Academic Search

Landfill leachate contains a variety of pollutants that may potentially contaminate the ground water and affect the quality of surface waters and well waters. The literature has been critically reviewed in order to assess the attenuation processes governing the contaminants in leachate?affected aquifers. After an introductory section on leachate composition, the physical and chemical frameworks for the attenuation processes are

Thomas H. Christensen; Peter Kjeldsen; Gorm Heron; Per H. Nielsen; Poul L. Bjerg; Peter E. Holm

1994-01-01

388

The new Waste Law: Challenging opportunity for future landfill operation in Indonesia.  

PubMed

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

Meidiana, Christia; Gamse, Thomas

2010-10-08

389

Biotic systems to mitigate landfill methane emissions.  

PubMed

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. PMID:18338700

Huber-Humer, Marion; Gebert, Julia; Hilger, Helene

2008-02-01

390

Analyses of gas composition in vacuum systems by mass spectrometry.  

PubMed

Analyses of the composition of residual gases for diagnostic purposes, analyses of the atmosphere enforced by the introduction of gases for technological purposes and analyses of gases released from analyte materials in numerous analytical methods (e.g. TSD, SIMS) are frequently carried out in vacuum systems. There is only a small amount of gas available, in the vacuum system so the most important property of a mass spectrometer is high sensitivity. As a consequence, the mass resolution is usually low. Moreover, a low outgassing rate of the mass spectrometer itself and all parts connecting it to the vacuum system is required. Dynamic mass spectrometry satisfies these demands best. Quadrupole mass spectrometers are almost solely utilized in applications, although the time-of-flight mass spectrometer has come into use recently. The main disadvantage of the quadrupole mass spectrometer is a strong dependence of the sensitivity and the mass discrimination factor on the stability of the supply voltages. Together with the necessity to use multipliers for detection of the ion current, this leads to a requirement for frequent recalibration. Another serious problem, that is met in such applications is the estimation of the gas composition from the measured mass spectra. Usually, the analyte gas mixtures consist of various individual gases, or at least are measured on a background of such mixtures. This implies a requirement for the exact knowledge of the fragmentation pattern of the gases, and again the necessity for frequent calibration over a satisfactorily wide range of mass numbers. Some theoretical considerations and some experimental results obtained by the authors are presented. PMID:12489090

Repa, P; Tesar, J; Gronych, T; Peksa, L; Wild, J

2002-12-01

391

NOVEL COMPOSITE MEMBRANES AND PROCESS FOR NATURAL GAS UPGRADING  

SciTech Connect

The first phase of this project involved the development of a high performance composite membranes for the treatment of natural gas. The objective of the second phase is to demonstrate the commercial potential of a full-size membrane module in a pilot scale field test. This phase is undertaken jointly with our commercial partner, UOP LLC. At the conclusion of Phase I, two composite membrane products had been developed for the enrichment (sweetening) of natural gas. The one was a low pressure membrane with a high CO{sub 2}/CH{sub 4} separation factor that falls within the target range of 25-30 (at 50 C) set for the program. This is a significant improvement over current commercial membranes that have separation factors of around 18-19. The second membrane had excellent high pressure capability and good contamination resistance, with a separation factor of 20-22. Based on the performance and the economic evaluation of the newly developed membranes, and with the input of UOP and DOE, it was decided to devote the demonstration phase of the program to the field testing and commercial evaluation of natural gas dehydration membranes. Due to the events of September 11, the program was also extended by 6 months until June 30, 2002. In Phase II, UOP has essentially completed preparation of the field test site. Site preparation included the re-design of the test system, purchase and installation of analytical equipment, and making the necessary piping and other hardware changes. IMS has produced two commercial sized dehydration membrane modules for the field tests. These have been successfully tested up to pressures expected in the field tests, and the modules have been shipped to the test site. The remainder of the program will comprise performance testing of the membrane modules, evaluation of the results and submission of the final report with recommendations.

Johann LeRoux

2002-02-01

392

Compositions and greenhouse gas emission factors of flared and vented gas in the Western Canadian Sedimentary Basin.  

PubMed

A significant obstacle in evaluating mitigation strategies for flaring and venting in the upstream oil and gas industry is the lack of publicly available data on the chemical composition of the gas. This information is required to determine the economic value of the gas, infrastructure and processing requirements, and potential emissions or emissions credits, all of which have significant impact on the economics of such strategies. This paper describes a method for estimating the composition of solution gas being flared and vented at individual facilities, and presents results derived for Alberta, Canada, which sits at the heart of the Western Canadian Sedimentary Basin. Using large amounts of raw data obtained through the Alberta Energy Resources Conservation Board, a relational database was created and specialized queries were developed to link production stream data, raw gas samples, and geography to create production-linked gas composition profiles for approximately half of the currently active facilities. These were used to create composition maps for the entire region, to which the remaining facilities with unknown compositions were geographically linked. The derived data were used to compute a range of solution gas composition profiles and greenhouse gas emission factors, providing new insight into flaring and venting in the region and enabling informed analysis of future management and mitigation strategies. Implications: Accurate and transparent determination of environmental impacts of flaring and venting of gas associated with oil production, and potential benefits of mitigation, is severely hampered by the lack of publicly available gas composition data. In jurisdictions within the Western Canadian Sedimentary Basin, frameworks exist for regulating and trading carbon offset credits but current potential for mitigation is limited by a lack of standardized methods for calculating CO2 equivalent emissions. The composition and emission factor data derived in this paper will be useful to industry, regulators, policy researchers, and entrepreneurs seeking statistically significant and openly available data necessary to manage and mitigate upstream flaring and venting activity and estimate greenhouse gas impacts. PMID:23019813

Johnson, Matthew R; Coderre, Adam R

2012-09-01

393

Feasibility of SiC Composite Structures for 1644 Deg Gas Turbine Seal Applications.  

National Technical Information Service (NTIS)

The feasibility of silicon carbide composite structures was evaluated for 1644 K gas turbine seal applications. The silicon carbide composites evaluated consisted of Si/SiC Silcomp (Trademark) - and sintered silicon carbide as substrates, both with attach...

R. Darolia

1979-01-01

394

Effects of natural gas composition on ignition delay under diesel conditions.  

National Technical Information Service (NTIS)

Effects of variations in natural gas composition on autoignition of natural gas under direct-injection (DI) diesel engine conditions were studied experimentally in a constant-volume combustion vessel and computationally using a chemical kinetic model. Fou...

J. D. Naber D. L. Siebers S. S. Di Julio C. K. Westbrook

1993-01-01

395

Determination of the electrical behaviour of surfactant treated polymer\\/carbon black composite gas sensors  

Microsoft Academic Search

The effect of surfactants on the properties of poly(vinyl acetate) (PVAc)\\/carbon black (CB) composite gas sensors was examined. Percolation curves of the composites with and without surfactant were prepared. The percolation curves of surfactant treated composites showed that the resistivity of the composite was increased due to better dispersion of the CB and also the prevention of the CB from

K. Arshak; E. Moore; L. Cavanagh; J. Harris; B. McConigly; C. Cunniffe; G. Lyons; S. Clifford

2005-01-01

396

Superfund record of decision (EPA Region 5): H. O. D. Landfill, Antioch, IL, September 28, 1998  

SciTech Connect

This decision document presents the selected remedy for the H.O.D. Landfill (the Site) in Antioch, Illinois. The selected remedy addresses the sources of the contamination by containment of the landfill and contaminated soils, and treatment of leachate and landfill gas. The major components of the selected remedy for the Site are: waste cap improvements; enhanced gas collection and treatment; enhanced leachate collection; leachate treatment; groundwater monitored natural attenuation; and institutional controls.

NONE

1998-11-01

397

Global Biogenic Emission of Carbon Dioxide from Landfills  

NASA Astrophysics Data System (ADS)

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 CO2 emission from landfills could be estimated about 8.8-13.2\\times103 million tons per year, equivalent to a 0.04-0.06 % of the fossil fuel emission of CO2.

Lima, R.; Nolasco, D.; Meneses, W.; Salazar, J.; Hernández, P.; Pérez, N.

2002-12-01

398

Remote measurements of volcanic gas compositions by solar occultation spectroscopy  

NASA Astrophysics Data System (ADS)

Volcanic gases have important effects on the atmosphere and climate, and are important indicators of subsurface magmatic processes,, but they are difficult to measure. In situ sampling on volcanoes can provide detailed information but is often impractical or hazardous. It is safer to apply remote techniques, for example correlation spectroscopy, which is now widely used to estimate emission rates of sulphur dioxide; but making remote measurements of other gas species has proved more difficult. Developments in Fourier-transform infrared spectroscopy, however, have shown promise. Here we report Fourier-transform infrared observations of volcanic plume compositions that we obtained by solar occultation at Mount Etna in 1997. We foundmolar ratios of SO2:HCl and SO2:HF to be ~4.0 and 10, corresponding to emission rates of HCl and HF of about 8.6 and 2.2kgs-1, respectively, confirming Mount Etna as the largest known sustained point source of these gases. Solar occultation spectroscopy has advantages over other methods as it enables measurement of plume compositions several kilometres downwind, without requiring hot rocks or lamp sources. The regular and frequent observation of volcanic gases provides a valuabletoolfor volcano surveillance, and data from plumes at different distances downwind of a volcano's summit may help us to understand the atmospheric chemistry involved in plume dispersal.

Francis, Peter; Burton, Mike R.; Oppenheimer, Clive

1998-12-01

399

Sanitary landfill leachate  

SciTech Connect

This article reviews landfill leachate treatment methods. Contamination of groundwater, streams, and ponds by noxious materials from landfills in particular, leachate is a problem going back to the first dump''. However, it has only relatively recently received the attention it deserves. Leachate, soluble chemical compounds removed from degrading solid waste materials, is produced when water (usually from precipitation) passes through a landfill. Its quality varies with its source, among other factors, and reported values of leachate constituents vary over a wide range. The quantity produced is primarily a function of climate, but it is also affected by landfill cover and the collection system's configuration. Because uncollected leachate may contaminate ground-water or surface water, current regulations require containment, collection, treatment, and leachate disposal.

Shams-Khorzani, R.; Knox, T.D.; Brockway, R.C. (Black and Veatch, Kansas City, MO (United States))

1994-06-01

400

Alterations of municipal solid waste incineration residues in a landfill.  

PubMed

Fresh municipal solid waste incineration residues (MSWIR) and a drilling core of 2-10 years old landfilled MSWIR were investigated to determine the alterations due to weathering in a landfill. Physical and geochemical properties and transformations of major components and heavy metals were analyzed for fresh and landfilled residues. Carbonates and hydroxides (10-12vol%) as major mineralogical compositions in the 8-10 years weathered MSWIR were observed by modal analysis of thin sections. Three step sequential extractions indicated that reducible phases, mainly the Fe, Al and Mn hydroxides increased with depth in the landfill. A pH controlled leaching test (including availability test and pH dependent leaching test) was then conducted. Results indicated lower concentrations of leachable contents at pH values from 6 to 10 for the four elements (Pb, Zn, Al and Fe) in the 8-10 years landfilled residues than in the fresh and 1-2 years landfilled residues. This means that 8-10 years weathered MSWIR became more stable than fresh landfilled residues. The reasons for the stabilization of these elements might be the hydration of Al and Fe during weathering in the landfill, which then results in the heavy metals adsorptions of these minerals. PMID:17656082

Shimaoka, T; Zhang, R; Watanabe, K

2007-07-25

401

RETROSPECTIVE EVALUATION OF THE EFFECTS OF SELECTED INDUSTRIAL WASTES ON MUNICIPAL SOLID WASTE STABILIZATION IN SIMULATED LANDFILLS  

EPA Science Inventory

The report is a retrospective evaluation of ten years of leachate and gas data collected from 19 simulated landfills (landfill cells) containing municipal solid waste codisposed with sewage sludge or industrial wastes. Physical and chemical parameters from each landfill cell are ...

402

Methanotrophic communities in a landfill cover soil as revealed by [ 13C] PLFAs and respiratory quinones: Impact of high methane addition and landfill leachate irrigation  

Microsoft Academic Search

The soil microbial communities of a landfill cover substrate, which was treated with landfill gas (100lCH4m?2d?1) and landfill leachate for 1.5 years, were investigated by phospholipid fatty acid (PLFA), ergosterol and respiratory quinone analyses. The natural 13C depletion of methane was used to assess the activity of methanotrophs and carbon turnover in the soil system. Under methane addition, the soil

Andrea Watzinger; Michael Stemmer; Michael Pfeffer; Frank Rasche; Thomas G. Reichenauer

2008-01-01

403

Analysis of AC breakdown of composite-insulation depending on gas pressure and solid insulation thickness  

Microsoft Academic Search

SF6 gas used widely as insulating component in electric power industry has excellent in insulation and arc extinguishing performance in gas-insulated switchgear. However, the concern about eco-friendly alternative gas is currently rising because SF6 gas is one of the main greenhouse gases. In this paper, dry-air and composite-insulation (dry-air + epoxy) as the alternative technology for SF6 gas insulation is

Hae-Eun Jung; Jae-Hun Yun; Chung Lee; Seong-Hwa Kang; Kyu-Boek Cho; Kee-Joe Lim

2008-01-01

404

Controlled landfill project: Mountain View, California. Annual report, January-December 1982  

Microsoft Academic Search

This project studied the effects of leachate recirculation and added water, buffer and sludge on enhancing the generation and improving the recovery of landfill gas. It evaluated the various techniques by providing individual control cells for the demonstration of enhancement methods. The study also documents landfill gas productions from a controlled volume at field scale. Results from this study provide

T. A. Bonham; R. E. Van Heuit; W. M. Carroll; M. Donch

1984-01-01

405

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...

406

Extraction wells and biogas recovery modeling in sanitary landfills.  

PubMed

A general methodology is established that permits the characterization and evaluation of the optimum potential of biogas extraction at each vertical well in the sanitary landfill of Asturias, Spain. Twenty wells were chosen from a total of 225 for the study, and the maximum production flow of biogas, which is a result of the degradation of the municipal solid waste deposited within its area of influence, was determined for each well. It was found that this flow varied with time and is characteristic of each extraction well. The maximum extractable flow also was determined as a function of the composition of the biogas needed for its subsequent utilization. The biogas extraction yield in the wells under study varied between approximately 26 and 97%, with a mean recovery value of 82%. The low yields found in certain cases were generally caused by a sealing defect, which leads to excessive incorporation of air into the landfill gas through the surrounding soil or through the extraction shaft, and which make its subsequent utilization difficult. PMID:15796107

Rodríguez-Iglesias, J; Vázquez, I; Marañón, E; Castrillón, L; Sastre, H

2005-02-01

407

[Bioreactor-landfill site for leaching solution treatment].  

PubMed

The study utilizes the system combined bioreactor with landfill site to treat leachate. The results show that the system helped the degradation of the organic pollutants in the leachate to be divided into two-phases, the hydrolytic fermentation and acid-production phases mainly occurred in the landfill site, the acidification rate was 40%-50%, the methane-production chiefly occurred in the bioreactor(UASB). It treated the leachate significantly and benefits the collection and utilization of methane gas. Also, the system accelerates the process of degrading municipal solid waste and stabilizing landfill site. PMID:11855193

He, R; Shen, D

2001-11-01

408

Gas permeability of SiC\\/SiC composites as fusion reactor material  

Microsoft Academic Search

Permeability of helium gas in SiC\\/SiC composites material, which is one of the most important properties in application of SiC\\/SiC composite for first wall and blanket of fusion reactors, was studied by using a vacuum apparatus. Three tubular and two flat plate SiC\\/SiC composites were prepared by different preparation processes. The measurement of permeability coefficient of helium gas was carried

Y Hirohata; T Jinushi; Y Yamauchi; M Hashiba; T Hino; Y Katoh; A Kohyama

2002-01-01

409

CATALYTIC CRACKING OF GAS OIL: EFFECT OF THE AMOUNT OF ZEOLITE IN COMPOSITE CATALYSTS  

Microsoft Academic Search

In the present paper the performance of a composite isothermal catalytic pellet in the cracking of Gas-Oil is examined theoretically. The composite pellet contains spherical particles of X-Zeolite uniformly dispersed in a Silica-Alumina matrix. It is assumed that the cracking of gas oil for the production of Gasoline can be described by three-lumped components. The composite pellet deactivates due to

PANAGIOTIS G. SMIRNIOTIS; ELI RUCKENSTEIN

1992-01-01

410

Dew point, internal gas pressure, and chemical composition of the gas within the free volume of DWPF canistered waste forms  

Microsoft Academic Search

The Defense Waste Processing Facility (DWPF) produced 55 canistered waste forms containing simulated waste glass during the four Waste Qualification campaigns of the DWPF Startup Test Program. Testing of the gas within the free volume of these canisters for dew point, internal gas pressure, and chemical composition was performed as part of a continuing effort to demonstrate compliance with the

J. R. Harbour; D. T. Herman; S. Crump; T. J. Miller; J. McIntosh

1996-01-01

411

Carbon Dioxide Gas Sensing Application of GRAPHENE/Y2O3 Quantum Dots Composite  

NASA Astrophysics Data System (ADS)

Graphene/Y2O3 quantum dots (QDs) composite was investigated towards the carbon dioxide (CO2) gas at room temperature. Graphene synthesized by electrochemical exfoliation of graphite. The composite prepared by mixing 20-wt% graphene into the 1 g Y2O3 in organic medium (acetone). The chemiresistor of composite prepared by screen-printing on glass substrate. The optimum value of sensing response (1.08) was showed by 20-wt% graphene/Y2O3 QDs composite. The excellent stability with optimum sensing response evidenced for the composite. The gas sensing mechanism discussed on the basis of electron transfer reaction.

Nemade, K. R.; Waghuley, S. A.

412

Study of gas transport properties of multi-walled carbon nanotubes\\/polystyrene composite membranes  

Microsoft Academic Search

The multi-walled carbon nanotube (MWCNT) dispersed polystyrene (PS) composite membranes have been prepared by solution cast method for hydrogen gas permeation application. The structural and morphological properties of these prepared composite membranes have been characterized by X-Ray diffraction (XRD), Atomic force microscopy (AFM) and Scanning electron microscopy (SEM). The optical absorbance measurement of the composite membranes has been carried out

Sumit Kumar; Subodh Srivastava; Y. K. Vijay

413

Elimination of methane generated from landfills by biofiltration: a review  

Microsoft Academic Search

The production of biogas in landfills, its composition and the problems resulting from its generation are all reviewed. Biofiltration\\u000a is a promising option for the control of emissions to atmosphere of the methane contained in biogas issued from the smaller\\u000a and\\/or older landfills. A detailed review of the methane biofiltration literature is presented. The microorganisms, mainly\\u000a the methanotrophs, involved in

J. Nikiema; R. Brzezinski; M. Heitz

2007-01-01

414

UV radiation of the GTA welding plasma versus shielding gas composition  

Microsoft Academic Search

UV radiation during gas tungsten arc (GTA) welding in argon\\/helium shielding gas mixtures versus gas composition and arc length has been investigated experimentally and theoretically. UV radiation was found to increase with an increase of argon concentration in the mixture. A physical model describing this phenomenon has been developed. The model predicts an increase in the total amount of ions

I. Ioffe; V. Koss; N. Perelman; D. Hilton

1997-01-01

415

Composite nuclear fuel fabrication methodology for gas fast reactors  

NASA Astrophysics Data System (ADS)

An advanced fuel form for use in Gas Fast Reactors (GFR) was investigated. Criteria for the fuel includes operation at high temperature (˜1400°C) and high burnup (˜150 MWD/MTHM) with effective retention of fission products even during transient temperatures exceeding 1600°C. The GFR fuel is expected to contain up to 20% transuranics for a closed fuel cycle. Earlier evaluations of reference fuels for the GFR have included ceramic-ceramic (cercer) dispersion type composite fuels of mixed carbide or nitride microspheres coated with SiC in a SiC matrix. Studies have indicated that ZrC is a potential replacement for SiC on account of its higher melting point, increased fission product corrosion resistance and better chemical stability. The present work investigated natural uranium carbide microspheres in a ZrC matrix instead of SiC. Known issues of minor actinide volatility during traditional fabrication procedures necessitated the investigation of still high temperature but more rapid fabrication techniques to minimize these anticipated losses. In this regard, fabrication of ZrC matrix by combustion synthesis from zirconium and graphite powders was studied. Criteria were established to obtain sufficient matrix density with UC microsphere volume fractions up to 30%. Tests involving production of microspheres by spark erosion method (similar to electrodischarge machining) showed the inability of the method to produce UC microspheres in the desired range of 300 to 1200 mum. A rotating electrode device was developed using a minimum current of 80A and rotating at speeds up to 1500 rpm to fabricate microspheres between 355 and 1200 mum. Using the ZrC process knowledge, UC electrodes were fabricated and studied for use in the rotating electrode device to produce UC microspheres. Fabrication of the cercer composite form was studied using microsphere volume fractions of 10%, 20%, and 30%. The macrostructure of the composite and individual components at various stages were characterized to understand the required fabrication techniques and at the same time meet the necessary GFR fuel characteristics.

Vasudevamurthy, Gokul

416

FULL-SCALE EXPERIENCES WITH LEACHATE RECIRCULATING LANDFILLS: CASE STUDIES  

Microsoft Academic Search

Leachate recirculation has been shown in lysimeter, pilot-scale and full-scale investigations to reduce the time required for waste stabilization, improve leachate quality, provide the opportunity for leachate volume reduction, and to enhance the rate of gas production. New generation full-scale landfills are implementing recirculation as a leachate management tool with increasing frequency. Leachate recirculation techniques used at full-scale landfills include

Debra R. Reinhart

1996-01-01

417

Municipal landfill leachate management  

SciTech Connect

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.

Kusterer, T.; Willson, R. [Montgomery County Div. of Solid Waste Services, Rockville, MD (United States); Bruce, S.C.; Tissue, E. Lou, P.J. [Roy F. Weston Inc., Philadelphia, PA (United States)

1998-12-31

418

Optimization of diagnostic microarray for application in analysing landfill methanotroph communities under different plant covers.  

PubMed

Landfill sites are responsible for 6-12% of global methane emission. Methanotrophs play a very important role in decreasing landfill site methane emissions. We investigated the methane oxidation capacity and methanotroph diversity in lysimeters simulating landfill sites with different plant vegetations. Methane oxidation rates were 35 g methane m-2 day-1 or higher for planted lysimeters and 18 g methane m-2 day-1 or less for bare soil controls. Best methane oxidation, as displayed by gas depth profiles, was found under a vegetation of grass and alfalfa. Methanotroph communities were analysed at high throughput and resolution using a microbial diagnostic microarray targeting the particulate methane monooxygenase (pmoA) gene of methanotrophs and functionally related bacteria. Members of the genera Methylocystis and Methylocaldum were found to be the dominant members in landfill site simulating lysimeters. Soil bacterial communities in biogas free control lysimeters, which were less abundant in methanotrophs, were dominated by Methylocaldum. Type Ia methanotrophs were found only in the top layers of bare soil lysimeters with relatively high oxygen and low methane concentrations. A competetive advantage of type II methanotrophs over type Ia methanotrophs was indicated under all plant covers investigated. Analysis of average and individual results from parallel samples was used to identify general trends and variations in methanotroph community structures in relation to depth, methane supply and plant cover. The applicability of the technology for the detection of environmental perturbations was proven by an erroneous result, where an unexpected community composition detected with the microarray indicated a potential gas leakage in the lysimeter being investigated. PMID:15008813

Stralis-Pavese, Nancy; Sessitsch, Angela; Weilharter, Alexandra; Reichenauer, Thomas; Riesing, Johann; Csontos, József; Murrell, J Colin; Bodrossy, Levente

2004-04-01

419

The chemical composition of ionized gas in galaxies  

NASA Astrophysics Data System (ADS)

Active star formation in galaxies takes place in HII regions harbouring young massive stars within an extended ionized gaseous component. Their relative structural simplicity andcharacteristic emission line spectrum make them ideal laboratories to study the physical properties and chemical composition of gas and stars in galaxies. Chemical abundancescan be derived for Galactic and relatively nearby extragalactic HII regions, as well as for distant galaxies, applying different techniques. In this talk an overview of the derivation of chemical abundances for HII regions in galaxies is presented, with an emphasis on the different domains of spatial resolution covered by the data, from spatially resolved integral field spectra of HII regions in the Milky Way and nearby galaxies to integrated spectra of more distant galaxies.With the upcome of the new integral field spectrographs a wide coverage at good spatial sampling of galaxies and HII complexes is now possible. This new 2D spectroscopy provides us more realistic information and useful constrains to study the chemical enrichment process of the interstellar medium and some of the fundamental relations governing galaxy evolution.

Vilchez, J. M.

2011-11-01

420

Generating CO{sub 2}-credits through landfill in situ aeration  

SciTech Connect

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.

Ritzkowski, M., E-mail: m.ritzkowski@tu-harburg.d [Institute of Environmental Technology and Energy Economics, Hamburg University of Technology, Harburger Schlossstr. 36, D-21079 Hamburg (Germany); Stegmann, R. [Consultants for Waste Management, Prof. R. Stegmann and Partner, Schellerdamm 19-21, D-21079 Hamburg (Germany)

2010-04-15

421

Selecting the ideal landfill site  

Microsoft Academic Search

The number of active landfills has decreased by nearly 3000 since 1984 as sites have run out of space and cannot be upgraded to meet tough new environmental requirements. How is the ideal landfill site defined This paper discusses the numerous considerations which would categorize an ideal landfill site. These include deep soils with low hydraulic conductivity; abundant workable soils

1989-01-01

422

Measurement of gas transport through fiber preforms and densified composites for chemical vapor infiltration  

Microsoft Academic Search

Gas transport via pressure-driven permeation or via concentration-driven diffusion is a key step in the chemical vapor infiltration (CVI) process. This paper describes methods for the measurement of these properties for CVI preforms and partially infiltrated composites. Results are presented for Nicalon-fiber cloth layup preforms and composites, Nextel-fiber braid preforms and composites, and a Nicalon-fiber three-dimensional (3-D) weave composite. The

T. L. Starr; N. Hablutzel

1998-01-01

423

Lubrication contributes to improved landfill cogeneration plant operation  

SciTech Connect

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.

NONE

1995-10-01

424

Assessment of municipal waste compost as a daily cover material for odour control at landfill sites  

Microsoft Academic Search

The ability of municipal waste compost as a daily cover material to reduce the odorous emissions associated with landfill surfaces was investigated. Trials were carried out using landfill gas, a certified sulphurous gas mix and ambient air as a control. Odorous gas was passed through portable test column filled with compost at different densities (590kg\\/m3 and 740kg\\/m3). Gas samples were

Claire Hurst; Philip Longhurst; Simon Pollard; Richard Smith; Bruce Jefferson; Jan Gronow

2005-01-01

425

GAS CHROMATOGRAPHIC RETENTION PARAMETERS DATABASE FOR REFRIGERANT MIXTURE COMPOSITION MANAGEMENT  

EPA Science Inventory

Composition management of mixed refrigerant systems is a challenging problem in the laboratory, manufacturing facilities, and large refrigeration machinery. Ths issue of composition management is especially critical for the maintenance of machinery that utilizes zeotropic mixture...

426

Effects of natural gas composition on ignition delay under diesel conditions  

NASA Astrophysics Data System (ADS)

Effects of variations in natural gas composition on autoignition of natural gas under direct-injection (DI) diesel engine conditions were studied experimentally in a constant-volume combustion vessel and computationally using a chemical kinetic model. Four fuel blends were investigated: pure methane, a capacity weighted mean natural gas, a high ethane content natural gas, and a natural gas with added propane typical of peak shaving conditions. Experimentally measured ignition delays were longest for pure methane and became progressively shorter as ethane and propane concentrations increased. At conditions characteristic of a DI compression ignition natural gas engine at Top Dead Center (CR = 23:1, p = 6.8 MPa, T = 1150K), measured ignition delays for the four fuels varied from 1.8 ms for the peak shaving and high ethane gases to 2.7 ms for pure methane. Numerically predicted variations in ignition delay as a function of natural gas composition agreed with these measurements.

Naber, J. D.; Siebers, D. L.; Dijulio, S. S.; Westbrook, C. K.

1993-12-01

427

Effects of natural gas composition on ignition delay under diesel conditions  

SciTech Connect

Effects of variations in natural gas composition on autoignition of natural gas under direct-injection (DI) diesel engine conditions were studied experimentally in a constant-volume combustion vessel and computationally using a chemical kinetic model. Four fuel blends were investigated: pure methane, a capacity weighted mean natural gas, a high ethane content natural gas, and a natural gas with added propane typical of peak shaving conditions. Experimentally measured ignition delays were longest for pure methane and became progressively shorter as ethane and propane concentrations increased. At conditions characteristic of a DI compression ignition natural gas engine at Top Dead Center (CR=23:1, p = 6.8 MPa, T = 1150K), measured ignition delays for the four fuels varied from 1.8 ms for the peak shaving and high ethane gases to 2.7 ms for pure methane. Numerically predicted variations in ignition delay as a function of natural gas composition agreed with these measurements.

Naber, J.D.; Siebers, D.L. [Sandia National Labs., Livermore, CA (United States); Di Julio, S.S. [California State Univ., Northridge, CA (United States). Dept. of Mechanical Engineering; Westbrook, C.K. [Lawrence Livermore National Lab., CA (United States)

1993-12-03

428

Landfilling of waste: accounting of greenhouse gases and global warming contributions.  

PubMed

Accounting of greenhouse gas (GHG) emissions from waste landfilling is summarized with the focus on processes and technical data for a number of different landfilling technologies: open dump (which was included as the worst-case-scenario), conventional landfills with flares and with energy recovery, and landfills receiving low-organic-carbon waste. The results showed that direct emissions of GHG from the landfill systems (primarily dispersive release of methane) are the major contributions to the GHG accounting, up to about 1000 kg CO(2)-eq. tonne( -1) for the open dump, 300 kg CO(2)-eq. tonne( -1) for conventional landfilling of mixed waste and 70 kg CO(2)-eq. tonne(-1) for low-organic-carbon waste landfills. The load caused by indirect, upstream emissions from provision of energy and materials to the landfill was low, here estimated to be up to 16 kg CO(2)-eq. tonne(-1). On the other hand, utilization of landfill gas for electricity generation contributed to major savings, in most cases, corresponding to about half of the load caused by direct GHG emission from the landfill. However, this saving can vary significantly depending on what the generated electricity substitutes for. Significant amounts of biogenic carbon may still be stored within the landfill body after 100 years, which here is counted as a saved GHG emission. With respect to landfilling of mixed waste with energy recovery, the net, average GHG accounting ranged from about -70 to 30 kg CO(2)-eq. tonne(- 1), obtained by summing the direct and indirect (upstream and downstream) emissions and accounting for stored biogenic carbon as a saving. However, if binding of biogenic carbon was not accounted for, the overall GHG load would be in the range of 60 to 300 kg CO(2)-eq. tonne( -1). This paper clearly shows that electricity generation as well as accounting of stored biogenic carbon are crucial to the accounting of GHG of waste landfilling. PMID:19808732

Manfredi, Simone; Tonini, Davide; Christensen, Thomas H; Scharff, Heijo

2009-10-06

429

Landfills: Building Them Better  

NSDL National Science Digital Library

Waste disposal has been an ongoing societal problem since medieval times. In this lesson, students learn about the three methods of waste disposal in use by modern communities. They also investigate how engineers design sanitary landfills to prevent leachate from polluting the underlining groundwater.

Integrated Teaching And Learning Program

430

HAZARDOUS WASTE LANDFILL RESEARCH  

EPA Science Inventory

The hazardous waste land disposal research program is collecting data necessary to support implementation of disposal guidelines mandated by the 'Resource Conservation and Recovery Act of 1976' (RCRA) PL 94-580. This program relating to the categorical area of landfills, surface ...

431

Attenuation of landfill leachate at two uncontrolled landfills  

NASA Astrophysics Data System (ADS)

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 different permeability divisions, the landfill region, the sandy open field and the paddy field. Roles of the landfill and paddy regions are very similar to those at the Cheonan. The very permeable sandy field receiving a large amount of rainwater infiltration plays a key role in controlling redox condition of the down gradient area and contaminant migration. This paper reports details of the attenuation and redox conditions of the landfill leachates at the two uncontrolled landfills.

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

432

Landfill methane emissions measured by enclosure and atmospheric tracer methods  

NASA Astrophysics Data System (ADS)

Methane (CH4) emissions were measured from the Nashua, New Hampshire municipal landfill using static enclosure and atmospheric tracer methods. The spatial variability of emissions was also examined using geostatistical methods. One hundred and thirty nine enclosure measurements were performed on a regular grid pattern over the emitting surface of the landfill resulting in an estimate of whole landfill emissions of 15,800 L CH4 min-1. Omnidirectional variograms displayed spatial correlation among CH4 fluxes below a separation distance of 7 m. Eleven tracer tests, using sulfur hexafluoride (SF6) as a tracer gas, resulted in a mean emissions estimate of 17,750 L CH4 min-1. The favorable agreement between the emission estimates was further refined using the observed relationship between atmospheric pressure and CH4 flux. This resulted in a pressure-corrected tracer flux estimate of whole landfill emissions of 16,740 L CH4 min-1.

Czepiel, P. M.; Mosher, B.; Harriss, R. C.; Shorter, J. H.; McManus, J. B.; Kolb, C. E.; Allwine, E.; Lamb, B. K.

1996-07-01

433

Development of computer simulations for landfill methane recovery  

SciTech Connect

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.

Massmann, J.W.; Moore, C.A.; Sykes, R.M.

1981-12-01

434

Petrology, Mineralogy, and Noble Gas Composition of the Dubrovnik L Chondrite Breccia  

NASA Astrophysics Data System (ADS)

Petrology, mineralogy, and noble gas composition of the Dubrovnik L chondrite breccia showing beautiful dark-light structure are characterized. It consists mainly of L6 material with minor amounts of less equilibrated material and experienced little heati

Yokoyama, T.; Nakamura, T.; Okazaki, R.; Saiki, K.

2007-03-01

435

Detailed internal characterisation of two Finnish landfills by waste sampling.  

PubMed

The aim of this study was to characterise the internal structure and composition of landfilled waste at two Finnish landfills to provide information for active and post-landfill operations. The two sites, Ammässuo and Kujala, have been in operation for 17 and 48 years, respectively. Waste was sampled (total 68 samples) and analysed for total solids (TS), volatile solids (VS), total Kjeldahl nitrogen (TKN), biological methane potential (BMP) and leaching of organic material (determined as chemical oxygen demand, COD) and ammonium nitrogen (NH(4)-N). The results showed high vertical and horizontal variability, which indicated that both the waste composition and state of degradation varied greatly in both landfills. Ammässuo was characterised by 2- to 4-fold higher BMP, NH(4)-N and COD leaching than Kujala. Moreover, the ratio of VS to TS was higher at Ammässuo, while TS content was lower. The highest mean BMPs (68 and 44 m(3)/t TS), TKN content (4.6 and 5.2 kg/t dry weight) and VS/TS ratio (65% and 59%) were observed in the middle and top layers; and the lowest mean BMP (21 and 8 m(3)/t TS), TKN content (2.4 kg/t dry weight, in both landfills) and VS/TS ratio (55% and 16% in Ammässuo and Kujala, respectively) in the bottom layers. In conclusion, waste sampling is a feasible way of characterising the landfill body, despite the high variation observed and the fact that the minimum number and size of samples cannot easily be generalized to other landfills due to different methods of waste management and different landfilling histories. PMID:17350245

Sormunen, Kai; Ettala, Matti; Rintala, Jukka

2007-03-09

436

Goal-based waste management strategy to reduce persistence of contaminants in leachate at municipal solid waste landfills  

Microsoft Academic Search

The required minimum 30-year post-closure care period for municipal solid waste (MSW) landfills can be shortened by reducing\\u000a or eliminating of MSW components with long-terms effect in gas and leachate. The objectives of this study were to evaluate\\u000a the relative persistence of landfill gas, leachate quantity, and selected leachate parameters using post-closure monitoring\\u000a data from a case study landfill in

Berrin Tansel; Banu Sizirici Yildiz

2011-01-01

437

Characteristics of landfill leachates in central Taiwan  

Microsoft Academic Search

Due to the complex nature of landfill leachates, the leachate treatment plants have difficulty to meet the current Taiwan EPA's effluent standards. Three typical types of landfills, closed landfill A, mixed landfill B (disposal of MSW with bottom ashes from MSW incinerators) and direct MSW landfill C, (disposal of MSW only), are investigated in this research in order to have

Huan-jung Fan; Hung-Yee Shu; Hsin-Sin Yang; Wen-Ching Chen

2006-01-01

438

Gas Gun Impact Analysis on Adhesives in Sandwich Composite Panels  

Microsoft Academic Search

\\u000a As the application of composite sandwich panels is ever increasing, there is an increasing interest in the impact damage that\\u000a occurs on these sandwich panels. Since these composite sandwich panels are constructed in various manners, analysis on different\\u000a panel construction practices is of interest. Specifically, when a sandwich composite is cured, a film adhesive or just the\\u000a prepreg resin system

Matthew Mordasky; Weinong Chen

439

Influence of deep gas-steam fluids on the composition of reservoir waters of oil and gas fields  

Microsoft Academic Search

In this work the conditions of the formation of low-mineral deep hydrocarbonate sodium waters of oil-and-gas fields are considered.\\u000a Analysis of the boron-bromine ratio of reservoir and condensed waters in several fields of Western Siberia shows that the\\u000a influx of endogenous high-temperature gas-steam fluids into zones containing sedimentogenic brines is a decisive factor in\\u000a the formation of the chemical composition

V. A. Vsevolozhsky; T. A. Kireeva

2010-01-01

440

Method and apparatus for off-gas composition sensing  

Microsoft Academic Search

An apparatus and method for non-intrusive collection of off-gas data in a steelmaking furnace includes structure and steps for transmitting a laser beam through the off-gas produced by a steelmaking furnace, for controlling the transmitting to repeatedly scan the laser beam through a plurality of wavelengths in its tuning range, and for detecting the laser beam transmitted through the off-gas

David Keith Ottesen; Sarah Williams Allendorf; Gary Lee Hubbard; David Ezechiel Rosenberg

1999-01-01

441

Seismic displacements of landfills and deformation of geosynthetics due to base sliding  

Microsoft Academic Search

Seismic design of waste landfills has been a subject of intense research over the past two decades, primarily due to the severe environmental impact of a potential failure. The majority of the related studies have been focused on the stability assessment of landfills utilizing permanent deformation methods. However, previous investigations have not fully addressed the impact of the composite liner

Varvara Zania; Yiannis Tsompanakis; Prodromos N. Psarropoulos

2010-01-01

442

Application of response surface methodology (RSM) for optimization of ammoniacal nitrogen removal from semi-aerobic landfill leachate using ion exchange resin  

Microsoft Academic Search

Disposal of untreated landfill leachate can be a source of hazard to receiving waters. Hence, treatment of landfill leachate is considered environmentally essential. In this study, optimization of ammoniacal nitrogen (NH3–N) removal from Malaysian semi-aerobic landfill stabilized leachate using synthetic cation ion exchange resin was investigated. An ideal experimental design was carried out based on Central Composite Design (CCD) with

Mohammed J. K. Bashir; Hamidi Abdul Aziz; Mohd Suffian Yusoff; Mohd. Nordin Adlan

2010-01-01

443

Estimate of methane emissions from US landfills. Final report, December 1992-January 1994  

SciTech Connect

The report describes the development of a statistical regression model used for estimating methane (CH4) emissions, which relates landfill gas (LFG) flow rates to waste-in-place data from 105 landfills with LFG recovery projects. The model has three linear segments, each of which applies to a distinct landfill size class. Assumptions were required to account for the recovery efficiency of LFG projects and for the probable oxidation of CH4 in the top soil cover of the landfill. The report details uncertainties which limit the quality of the above estimates. The report concludes with a discussion of trends which will affect future LFG emissions, as well as LFG utilization.

Doorn, M.R.J.; Stefanski, L.A.; Barlaz, M.A.

1994-09-01

444

Estimate of global methane emissions from landfills and open dumps. Final report, January 1992-September 1994  

SciTech Connect

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. CH4 produced by the anaerobic decomposition of waste buried in landfills and open dumps is a significant contributor to global CH4 emissions, with estimates ranging from 10 to 70 Tg/yr. Methods of managing solid waste vary widely, ranging from open dumps and open burning to sanitary landfills with leachate collection systems and LFG control.

Doorn, M.R.J.; Barlaz, M.A.

1995-02-01

445

Metallic coating of aerospace carbon\\/epoxy composites by the pulsed gas dynamic spraying process  

Microsoft Academic Search

A method for applying metallic coatings to high fibre volume fraction aerospace carbon\\/epoxy polymer matrix composites is presented. The pulsed gas dynamic spraying process was used for depositing zinc coatings on composites featuring a thin layer of copper particles co-cured into the laminate. No surface preparation was required on the cured substrates prior to spraying hence no damage was induced

F. Robitaille; M. Yandouzi; S. Hind; B. Jodoin

2009-01-01

446

Soil gas composition provides evidence of in situ biodegradation of organic contaminants  

SciTech Connect

Soil gas within transport distance of aerobic biodegradation activity may be depleted in O{sub 2} and enriched in CO{sub 2}, compared to gas in similar uncontaminated sediments. This study compares soil gas composition at two uncontaminated control sites to a gasoline-contaminated site at which bacterial degradation of gasoline is suspected. At a site at Lawrence Livermore National Laboratory (LLNL), gasoline spilled before 1980 contaminates alluvial sediments to below the current water table (100 ft). Soil vapor was extracted intermittently from a multiply screened central well during 1988--90, possibly enhancing microbial activity. A microbiological study of other LLNL workers found bacteria populations, including in vitro gasoline degraders, to be much greater at the gasoline contaminated site than at the one control site they examined. Soil gas composition in the bacterially populated gasoline spill appears to be distinct from soil gas in nearby geologically similar uncontaminated sites. O{sub 2} concentrations is more distinct and more free from complicating factors than CO{sub 2}. Soil gas composition data indicate active bacterial respiration at the gasoline site. The gas composition and isotopic data provide evidence that supports existing microbial data suggesting that gasoline is being biodegraded at this site. In early investigations of a site, measurement of soil gas O{sub 2} and CO{sub 2} could provide an inexpensive first indicator of biodegradation activity. During and after remedial actions, these measurements might be used to help monitor biodegradation processes.

Camp, D.W.

1992-03-01

447

Purification of synthesis gas and correction of its composition for obtaining liquid hydrocarbons  

NASA Astrophysics Data System (ADS)

Results from calculated and design works on elaborating stages through which synthesis gas used for producing liquid synthetic hydrocarbons is purified and refined are presented. Two stages of high-temperature desulfurization are used for removing sulfur from gas, and steam conversion is used for correcting its composition.

Epikhin, A. N.; Somov, A. A.

2011-06-01

448

Secondary Porosity and Permeability of Coal vs. Gas Composition and Pressure  

Microsoft Academic Search

We have been investigating the sequestration of atmospheric pollutants by injection into coal seams while at the same time enhancing hydrocarbon productivity by displacement of methane with pollutants. We found that changing the composition of the gas sorbed into the coal changes the porosity and permeability of the coal natural-fracture system owing to gas-content changes, which cause matrix swelling or

Matthew Mavor; William Gunter

2006-01-01

449

The isotopic compositions of molecular nitrogen: implications on their origins in natural gas accumulations  

Microsoft Academic Search

The isotopic compositions of N2 (?15N, ‰, atm) imply the geochemical origins of molecular nitrogen in natural gas accumulations, but the irregular variation of ?15NN2 for most petroliferous basins puzzles scientists. We believe that this is due to multiple origins of N2 which are often mixed together and leads to the irregularities in gas pools. The four petroliferous basins, the

Yuenian Zhu; Buqing Shi; Chaobin Fang

2000-01-01

450

Evolution of volcanic gas composition during repeated culmination of volcanic activity at Kuchinoerabujima volcano, Japan  

Microsoft Academic Search

Chemical and isotopic compositions of low to medium temperature fumarolic gasses were measured at various fumaroles of Kuchinoerabujima volcano from 1993 to 2009 by the combination of fumarolic gas sampling and Multi-GAS measurement of volcanic plumes. Repeated culmination of the volcanic activity was observed as contemporaneous occurrence of seismic swarms, summit inflation and demagnetization, almost every two years after 1999.

H. Shinohara; J. Hirabayashi; K. Nogami; M. Iguchi

2011-01-01

451

Landfill Methane Recovery. Part 3. Data analysis and instrumentation needs. Final report, January-September 1983  

Microsoft Academic Search

This study expanded the level of data analysis for the existing volatile organic compound (VOC) data base from Landfill Methane Recovery Part II: Gas Characterization and determined the current instrumentation needs of the landfill methane recovery (LMR) industry. The VOC data analysis was conducted by statistically analyzing the Part II VOC data base using a computer-drive statistical package. The analysis

R. E. Zimmerman; G. Lytwynyshyn; N. W. Flynn

1983-01-01

452

Effects of Leachate Irrigation on Landfill Vegetation and Subsequent Methane Emissions  

Microsoft Academic Search

Short-rotation tree forests are irrigated with landfill leachate to reduce both leachate volume and nutrient content. It is of interest both for leachate treatment and energy recovery to optimise the productivity of such plantations. This study's aim was to investigate the effects of irrigation on soil quality, tree growth and on emissions of landfill gas (LFG) produced in the wastes.

C. Maurice; M. Ettala; A. Lagerkvist

1999-01-01

453

Brownfields and health risks--air dispersion modeling and health risk assessment at landfill redevelopment sites.  

PubMed

Redevelopment of landfill sites in the New Jersey-New York metropolitan area for recreational (golf courses), commercial, and even residential purposes seems to be gaining acceptance among municipal planners and developers. Landfill gas generation, which includes methane and potentially toxic nonmethane compounds usually continues long after closure of the landfill exercise phase. It is therefore prudent to evaluate potential health risks associated with exposure to gas emissions before redevelopment of the landfill sites as recreational, commercial, and, especially, residential properties. Unacceptably high health risks would call for risk management measures such as limiting the development to commercial/recreational rather than residential uses, stringent gas control mechanisms, interior air filtration, etc. A methodology is presented for applying existing models to estimate residual landfill hazardous compounds emissions and to quantify associated health risks. Besides the toxic gas constituents of landfill emissions, other risk-related issues concerning buried waste, landfill leachate, and explosive gases were qualitatively evaluated. Five contiguously located landfill sites in New Jersey intended for residential and recreational redevelopment were used to exemplify the approach. PMID:16869439

Ofungwu, Joseph; Eget, Steven

2006-07-01

454

Isotope fractionation effects by diffusion and methane oxidation in landfill cover soils  

Microsoft Academic Search

When the open system isotope method has been used to determine the methane oxidation efficiency of a landfill cover soil, it has been assumed that gas transport from the landfill is primarily driven by advection, a mechanism that is not associated with isotopic fractionation. A controlled laboratory experiment revealed that this approach underestimated the methane oxidation efficiency because it underestimated

Alex De Visscher; Ingrid De Pourcq; Jeffrey Chanton

2004-01-01

455

Microbial oxidation of CH 4 at different temperatures in landfill cover soils  

Microsoft Academic Search

Biological oxidation of CH4 is an important constraint on the emission of this gas from areas, such as landfills to the atmosphere. We studied the effect of temperature on methanotrophic bacteria in three different landfill cover soils, incubated in the laboratory. In samples of a young cover, consisting of wood chips and sewage sludge, the phospholipid fatty acids (PLFAs), regarded

Gunnar Börjesson; Ingvar Sundh; Bo Svensson

2004-01-01

456

Acetate synthesis from H2\\/CO2 in simulated and actual landfill samples  

Microsoft Academic Search

To investigate the characteristics of biological decomposition in a municipal solid waste landfill, laboratory simulated samples and full?scale actual samples excavated from landfills in Taiwan were used. Nitrogen gas was produced continuously in the simulated samples. Although nitrate or nitrite could not be detected in the leachate, this did not indicate that nitrate or nitrite was not available in the

A. Ohashi; H. Harada

2003-01-01

457

Improving Corrosion Resistance of Ti–TiB Composite Using Gas Tungsten Arc Heating  

Microsoft Academic Search

Titanium composites are used for applications requiring a combination of specific strength and corrosion resistance. Titanium–titanium boride (Ti–TiB) composite is gaining importance for some specific applications like armors of military hardware, biomedical applications, and its ease of making through routes like reactive sintering. In this research work, the surface of the Ti–TiB composite has been modified using Gas Tungsten Arc

P. Chandrasekar; V. Vijay; V. Balusamy; P. Chandramohan

2011-01-01

458

Transparent and high gas barrier films based on poly(vinyl alcohol)\\/graphene oxide composites  

Microsoft Academic Search

Composites of poly(vinyl alcohol) (PVA) and graphene oxide (GO) were synthesized by a modified Hummers method and a solution-mixing method. GO was fully exfoliated in the PVA\\/GO composites. GO did not affect the crystallization of PVA during solvent evaporation. GO is itself an excellent gas barrier without any chemical reduction. The oxygen permeability of the PVA\\/GO (0.3wt.%) composite coated film

Hye Min Kim; Jung Kyoo Lee; Heon Sang Lee

2011-01-01

459

Carbon black\\/polystyrene composites as candidates for gas sensing materials  

Microsoft Academic Search

Amorphous polymer-based composites consisting of polystyrene and carbon black were developed in the current work as candidates for gas sensing materials. With the help of polymerization filling, i.e., in-situ polymerization of styrene in the presence of carbon black, the composites were provided with low percolation threshold. The experimental results indicated that the composites have selective sensitivity as characterized by high

Jun Rong Li; Jia Rui Xu; Ming Qiu Zhang; Min Zhi Rong

2003-01-01

460

Development of a coupled reactor model for prediction of organic contaminant fate in landfills.  

PubMed

Models describing the behavior of organic chemicals in landfills can be useful to predict their fate and transport and also to generate input data for estimates of exposure and risk. The landfill coupled-reactor (LFCR) model developed in this work simulates a landfill as a series of fully mixed reactors, each representing a daily volume of waste. The LFCR model is a numerical model allowing time-variable input parameters such as gas generation, and cover type and thickness. The model was applied to three volatile organic chemicals (acetone, toluene, benzene) as well as naphthalene and the chemical warfare agent sarin under three landfill conditions (conventional, arid, bioreactor). Sarin was rapidly hydrolyzed, whereas naphthalene was largely associated with the landfill solid phase in all scenarios. Although similar biodegradation rates were used for acetone and toluene, toluene was more persistent in the landfill due to its hydrophobicity. The cover soil moisture content had a significant impact on gaseous diffusive losses. PMID:18939584

Lowry, Michael I; Bartelt-Hunt, Shannon L; Beaulieu, Stephen M; Barlaz, Morton A

2008-10-01

461

[Research advances in control of N2O emission from municipal solid waste landfill sites].  

PubMed

Landfill is one of the main approaches for municipal solid waste treatment, and landfill site is a main emission source of greenhouse gases nitrous oxide (N2O) and methane (CH4). As a high-efficient trace greenhouse gas, N2O has a very high warming potential, with a warming capacity 296 times of CO2, and has a long-term stability in atmosphere, giving greater damage to the ozone layer. Aiming at the researches in the control of N2O emission from municipal solid waste landfill sites, this paper summarized the characteristics and related affecting factors of the N2O emission from the landfill sites, and put forward a series of the measures adaptable to the N2O emission control of present municipal solid waste landfill sites in China. Some further research focuses on the control of N2O emission from the landfill sites were also presented. PMID:22919857

Cai, Chuan-Yu; Li, Bo; Lü, Hao-Hao; Wu, Wei-Xiang

2012-05-01

462

Gas transport properties and structural order of poly(4,4?-oxydiphenylene piromelliteimide) in composite membranes  

Microsoft Academic Search

Specific physico-chemical properties of aromatic polyimides determine their high selectivity in gas separation and relatively low gas permeability. Gas transport properties of insoluble polyimides may be improved in the process of membrane formation. A two-stage process was used for making composite membranes comprised of poly(4,4?-oxydiphenylene pyromelliteimide) (PI) and poly(2,6-dimethyl-1,4-phenylene oxide) (PPO). In the first stage the polyamic acid (PAA)\\/PPO membrane

G. A. Polotskaya; T. A. Kostereva; G. K. Elyashevich

1998-01-01

463

Correlating phospholipid fatty acids (PLFA) in a landfill leachate polluted aquifer with biogeochemical factors by multivariate statistical methods  

Microsoft Academic Search

Different multivariate statistical analyses were applied to phospholipid fatty acids representing the biomass composition and to different biogeochemical parameters measured in 37 samples from a landfill contaminated aquifer at Grindsted Landfill (Denmark). Principal component analysis and correspondence analysis were used to identify groups of samples showing similar patterns with respect to biogeochemical variables and phospholipid fatty acid composition. The principal

L Ludvigsen; H.-J Albrechtsen; H Holst; T. H Christensen

1997-01-01