Landfill gas migration
Encyclopedia
Landfill gas migration is a complex process of the gas moving from the site of original deposition to other places via diffusion
. Usually, the gas moves from areas of high concentration to areas of low gas concentration around a landfill. The process is also affected by the permeability of the ground and other factors, such as pressure differences in the soil, cavities, pipes, and tunnels. Changes in atmospheric pressure
and the water table can encourage this migration.
These gases can include methane
, carbon dioxide
, hydrogen
, and volatile organic compounds (there are approximately 500 others that can be present in trace forms) from the waste on site and its degradation over time.
Steps must be taken to prevent this migration from the landfill site as it might enter buildings in the vicinity. This can be done on the site by means of combinations of geomembranes
and clay based products, see gas protection
.
for buildings should consist of an impermeable gas membrane and also a layer where the gas will collect and be vented in a controlled manner.
Guidance for this in the U.K can be found in CIRCA 665 and also BS 8485 and Title 40 of the United State Code of Federal Regulations, parts 239 through 282. This subchapter, I, was initially promulgated in 1976 and is also known as the Resource Conservation and Recovery Act
.
Diffusion
Molecular diffusion, often called simply diffusion, is the thermal motion of all particles at temperatures above absolute zero. The rate of this movement is a function of temperature, viscosity of the fluid and the size of the particles...
. Usually, the gas moves from areas of high concentration to areas of low gas concentration around a landfill. The process is also affected by the permeability of the ground and other factors, such as pressure differences in the soil, cavities, pipes, and tunnels. Changes in atmospheric pressure
and the water table can encourage this migration.
These gases can include methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
, carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
, hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
, and volatile organic compounds (there are approximately 500 others that can be present in trace forms) from the waste on site and its degradation over time.
Steps must be taken to prevent this migration from the landfill site as it might enter buildings in the vicinity. This can be done on the site by means of combinations of geomembranes
Geomembranes
Geomembranes are a kind of geosynthetic material made up of an impermeable membranes. Their use includes lining canals, ponds and also waste containment.-Composition:Geomembranes are made of various materials...
and clay based products, see gas protection
Gas protection
Gas protection is a technical solution to prevent or to control gas penetration into properties. The control of gas migration is normally achieved by blocking the pathway or removing the source of the gas generation...
.
Gas protection
Gas protectionGas protection
Gas protection is a technical solution to prevent or to control gas penetration into properties. The control of gas migration is normally achieved by blocking the pathway or removing the source of the gas generation...
for buildings should consist of an impermeable gas membrane and also a layer where the gas will collect and be vented in a controlled manner.
Guidance for this in the U.K can be found in CIRCA 665 and also BS 8485 and Title 40 of the United State Code of Federal Regulations, parts 239 through 282. This subchapter, I, was initially promulgated in 1976 and is also known as the Resource Conservation and Recovery Act
Resource Conservation and Recovery Act
The Resource Conservation and Recovery Act , enacted in 1976, is the principal Federal law in the United States governing the disposal of solid waste and hazardous waste.-History and Goals:...
.
See also
- Anaerobic digestionAnaerobic digestionAnaerobic digestion is a series of processes in which microorganisms break down biodegradable material in the absence of oxygen. It is used for industrial or domestic purposes to manage waste and/or to release energy....
- Atmospheric methaneAtmospheric methaneAtmospheric methane levels are of interest due to its impact on climate change. Atmospheric methane is one of the most potent and influential greenhouse gases on Earth. The 100-year global warming potential of methane is 25, i.e...
- Final coverFinal coverFinal cover is a multilayered system of various materials which are primarily used to reduce the amount of storm water that will enter a landfill after closing...
- Environment of the United StatesEnvironment of the United StatesThe environment of the United States comprises diverse biotas, climates, and geologies. Environmental regulations and the environmental movement have emerged to respond to the various threats to the environment.-Animals:...
- Environmental issues in the United StatesEnvironmental issues in the United StatesAs with many other countries there are a number of environmental issues in the United States.-Climate change:The United States is the second largest emitter, after China, of carbon dioxide from the burning of fossil fuels. The energy policy of the United States is widely debated; many call on the...
- Landfill gas monitoringLandfill gas monitoringLandfill gas monitoring is the process by which gases that are released from landfills are electronically monitored.-Techniques for the monitoring of landfill gas:...
- Landfill gas utilizationLandfill gas utilizationLandfill gas utilization is a process of gathering, processing, and treating the gas to produce electricity, heat, fuels, and various chemical compounds. The number of landfill gas projects, which convert the methane gas that is emitted from decomposing garbage into power, went from 399 in 2005 to...
- Waste minimisationWaste minimisationWaste minimization is the process and the policy of reducing the amount of waste produced by a person or a society.Waste minimization involves efforts to minimize resource and energy use during manufacture. For the same commercial output, usually the fewer materials are used, the less waste is...