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Gas protection is the prevention or control of the penetration of hazardous gases into buildings or other types of real property. It usually involves either blocking entry pathways or removing the source of the gas.
Methane (which is flammable at 5-15% by volume in air) and carbon dioxide (which is toxic) are the most relevant gases, especially following two gas explosions in the 1980s in Loscoe and Abbeystead, England. [1]
UK regulatory bodies such as Building Research Establishment, British Standards, the Department of Environment, and others in the construction industry have developed and published guidance for preventing such gasses from entering buildings. Their production in the environment is associated with coal seams, deposited river silt, sewage, landfill waste, and peat.
In the case of landfill gas migration, gas is produced by organic materials in the waste degrading over time. Typically 40% carbon dioxide (CO
2) and 60% methane (CH
4) by volume, this gas can be heavier than air or lighter depending on the concentration (which varies from time to time), but will move from an area of high pressure to one at a lower pressure irrespective of its relative density.
Systems to prevent gas ingress include a passive barrier or, less commonly, an active system. Passive systems utilize a barrier with low permeability, such as a membrane. Active systems are mostly employed on commercial properties because of the associated costs. There are two main practical types of active systems to prevent the ingress of gases into buildings: positive pressurization, and forced ventilation. [2]
Both passive and active systems require "gas integrity testing", most often using the NHBC traffic light system. This is because the conditions under which gas membranes are installed are often difficult and can adversely compromise the integrity required by the manufacturer or client. The purpose of the test is to ensure integrity and allow the installation to be certified if the method of protection performs correctly.
The membrane is tested immediately after installation and prior to being covered up by any following construction processes. The area below the membrane is temporarily pressurized with a mixture of clean air and a non-toxic and inert tracer gas that is sensitive to detection. Special equipment is then used to trace all leaks within the installation, with particular attention being paid to critical points and junctions formed between the membrane material and other structural elements prior to conducting a sweep of the complete area. Any leaks are identified and sealed, and the membrane is re-tested before it passes and the certificate is issued.
Active systems require a test of the alarm in case of failure of the system or power supply and possible buildup of gas.
Biogas is the mixture of gases produced by the breakdown of organic matter in the absence of oxygen (anaerobically), primarily consisting of methane and carbon dioxide. Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste or food waste. Biogas is a renewable energy source. In India, it is also known as "Gobar Gas".
A landfill site, also known as a tip, dump, rubbish dump, garbage dump, or dumping ground, is a site for the disposal of waste materials. Landfill is the oldest and most common form of waste disposal, although the systematic burial of the waste with daily, intermediate and final covers only began in the 1940s. In the past, refuse was simply left in piles or thrown into pits; in archeology this is known as a midden.
Incineration is a waste treatment process that involves the combustion of organic substances contained in waste materials. Incineration and other high-temperature waste treatment systems are described as "thermal treatment". Incineration of waste materials converts the waste into ash, flue gas and heat. The ash is mostly formed by the inorganic constituents of the waste and may take the form of solid lumps or particulates carried by the flue gas. The flue gases must be cleaned of gaseous and particulate pollutants before they are dispersed into the atmosphere. In some cases, the heat that is generated by incineration can be used to generate electric power.
A waste-to-energy plant is a waste management facility that combusts wastes to produce electricity. This type of power plant is sometimes called a trash-to-energy, municipal waste incineration, energy recovery, or resource recovery plant.
A leachate is any liquid that, in the course of passing through matter, extracts soluble or suspended solids, or any other component of the material through which it has passed.
A gas leak refers to an unintended leak of natural gas or another gaseous product from a pipeline or other containment into any area where the gas should not be present. Gas leaks can be hazardous to health and the environment. Even a small leak into a building or other confined space may gradually build up an explosive or lethal concentration of gas. Leaks of natural gas and refrigerant gas into the atmosphere are especially harmful due to their global warming potential and ozone depletion potential.
Landfill gas is a mix of different gases created by the action of microorganisms within a landfill as they decompose organic waste, including for example, food waste and paper waste. Landfill gas is approximately forty to sixty percent methane, with the remainder being mostly carbon dioxide. Trace amounts of other volatile organic compounds (VOCs) comprise the remainder (<1%). These trace gases include a large array of species, mainly simple hydrocarbons.
A gas flare, alternatively known as a flare stack, is a gas combustion device used in industrial plants such as petroleum refineries, chemical plants and natural gas processing plants. They are also common at oil or gas extraction sites having oil wells, gas wells, offshore oil and gas rigs and landfills.
Bunding, also called a bund wall, is a constructed retaining wall around storage "where potentially polluting substances are handled, processed or stored, for the purposes of containing any unintended escape of material from that area until such time as a remedial action can be taken."
Biodegradable waste includes any organic matter in waste which can be broken down into carbon dioxide, water, methane or simple organic molecules by micro-organisms and other living things by composting, aerobic digestion, anaerobic digestion or similar processes. In waste management, it also includes some inorganic materials which can be decomposed by bacteria. Such materials include gypsum and its products such as plasterboard and other simple organic sulfates which can decompose to yield hydrogen sulphide in anaerobic land-fill conditions.
Plasma gasification is an extreme thermal process using plasma which converts organic matter into a syngas which is primarily made up of hydrogen and carbon monoxide. A plasma torch powered by an electric arc is used to ionize gas and catalyze organic matter into syngas, with slag remaining as a byproduct. It is used commercially as a form of waste treatment and has been tested for the gasification of refuse-derived fuel, biomass, industrial waste, hazardous waste, and solid hydrocarbons, such as coal, oil sands, petcoke and oil shale.
A gas detector is a device that detects the presence of gases in an area, often as part of a safety system. This type of equipment is used to detect a gas leak or other emissions and can interface with a control system so a process can be automatically shut down. A gas detector can sound an alarm to operators in the area where the leak is occurring, giving them the opportunity to leave. This type of device is important because there are many gases that can be harmful to organic life, such as humans or animals.
In the densely populated Hong Kong, waste is a complex issue. The territory generates around 6.4 million tons of waste each year but is able to collect and process only a minimal portion of recyclable waste. By 2019, its existing landfills are expected to be full. The government has introduced waste management schemes and is working to educate the public on the subject. On the commercial side, producers are taking up measures to reduce waste.
Waste are unwanted or unusable materials. Waste is any substance which is discarded after primary use, or is worthless, defective and of no use. A by-product by contrast is a joint product of relatively minor economic value. A waste product may become a by-product, joint product or resource through an invention that raises a waste product's value above zero.
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.
Municipal solid waste (MSW) – more commonly known as trash or garbage – consists of everyday items people use and then throw away, such as product packaging, grass clippings, furniture, clothing, bottles, food scraps and papers. In 2010, Americans generated about 250 million short tons (230 Mt) of trash. In the United States, landfills are regulated by the Environmental Protection Agency (EPA) and the states' environmental agencies. Municipal solid waste landfills (MSWLF) are required to be designed to protect the environment from contaminants that may be present in the solid waste stream.
Landfill gas utilization is a process of gathering, processing, and treating the methane or another gas emitted from decomposing garbage to produce electricity, heat, fuels, and various chemical compounds. After fossil fuel and agriculture, landfill gas is the third largest human generated source of methane. Compared to CO
2, methane is 25 times more effective as a greenhouse gas. It is important not only to control its emission but, where conditions allow, use it to generate energy, thus offsetting the contribution of two major sources of greenhouse gases towards climate change. The number of landfill gas projects, which convert the gas into power, went from 399 in 2005 to 519 in 2009 in the United States, according to the US Environmental Protection Agency. These projects are popular because they control energy costs and reduce greenhouse gas emissions. These projects collect the methane gas and treat it, so it can be used for electricity or upgraded to pipeline-grade gas. These projects power homes, buildings, and vehicles.
The former Operating Industries Inc. Landfill is a Superfund site located in Monterey Park, California at 900 N Potrero Grande Drive. From 1948 to 1984, the landfill accepted 30 million tons of solid municipal waste and 300 million US gallons (1,100,000 m3) of liquid chemicals. Accumulating over time, the chemical waste polluted the air, leached into groundwater, and posed a fire hazard, spurring severely critical public health complaints. Recognizing OII Landfill's heavy pollution, EPA placed the financial responsibility of the dump's clean-up on the main waste-contributing companies, winning hundreds of millions of dollars in settlements for the protection of human health and the environment.
klMyEnvironment is an application built by the United States Environmental Protection Agency (EPA) to help the public get a sense of environmental indicators in their neighborhood. By keying in a geography, the application comes back with information about the local land, air, water, climate, and Environmental Justice. It mines mostly EPA but also other federal Agency databases. The latest enhancement was a complete update to website including updating the environmental topics and the tools within each topic. The intention is that as people are learning about air and water quality in their neighborhood, they can simultaneously learn about environmental justice and what they can do to help their community.