In mid-April, a series of national biosafety standards came into force for the first time.
Three documents in this series are aimed at eliminating landfill gas (biogas) - a mixture of methane and carbon dioxide generated during the anaerobic (oxygen-free) decomposition of organic waste at municipal solid waste (MSW) landfills.
GOST R 59416-2021 «Biological safety. Landfill gas collection system at MSW landfills, consisting of special vertical gas weels. General specifications».
The standard establishes general requirements for technology, materials and safety of a landfill gas collection system at MSW landfills.
According to this system, biogas is removed from the «body» of the landfill through a system of gas-collecting wells, collected by a gas-collecting station, and then transported and neutralized.
The system should be so powerful that about 1.0-2.0 m3 / h of landfill gas could be pumped out from each meter of the gas well.
In the construction of gas wells, pipes with perforated holes with a diameter of 12 mm are used.
Gas gathering pipelines, which ensure the connection of gas wells with the gas gathering station, are laid with a slope of at least 5% to a depth of 1.0-3.5 m.
The gas gathering station is a solid structure in which several gas gathering pipelines are connected to a common gas manifold. In it, condensate is separated from the biogas stream, which is then transferred to the treatment facilities to specialized facility.
GOST R 59417-2021 «Biological safety. High-temperature flare installations for disposal of landfill gas with a predrying and gas cleaning system. General specifications»
Landfill gas neutralization technology using high-temperature flare units reduces the negative impact of the MSW landfill both at the local level (for the nearest settlements) and at the global level.
At the local level, it eliminates unpleasant odors coming from the landfill. Globally - to reduce the greenhouse gas quality, reduce the level of fire and explosion hazard in the landfill.
Pre-treated biogas is continuously supplied to the HTF by a gas compressor station. In the HTF chambers, the gas is thermally oxidized - it burns out at temperatures above 1000 ° C. This temperature ensures the complete decomposition of complex organic compounds of waste to the simplest components, without the formation of smoke, soot, ash and other products of incomplete combustion.
HTFs are equipped with an isolated combustion chamber, a burner for optimal mixing of landfill gas and primary air, electric shutters to regulate the flow of air into the combustion chamber, and a UV sensor for operational control.
GOST R 59416-2021 «Biological safety. Determination of biogas biological potential of municipal solid waste landfills and pumping biogas from vertical wells with flare plant utilization. General specifications».
Determination of the biogas potential of the MSW landfill allows you to establish the volumes and pressure of gas collected by the degassing system. This makes it possible to prevent uncontrolled emissions and gas dispersion in the atmosphere.
This approach ensures the biological safety of disposal and collection of landfill gas at all stages of its purification.
The technological scheme for the extraction and collection of landfill gas consists of a network of observation gas wells connected by gas pipelines, in which a compressor unit creates a vacuum required to transport landfill gas to the sampling site.
With a large area of location of observation gas wells, they are combined by clusters in gas gathering stations equipped with measuring and analyzing devices.
The work time for the study of the biogas potential of the MSW landfill is from 3 to 12 months.
Also, this month came into force:
GOST R 59418-2021 «Biological safety. Reverse osmosis treatment of waste, industrial, surface water and filtrate of municipal solid waste landfills. General specifications».
GOST R 59419-2021 «Biological safety. Slope stabilization system for municipal solid waste landfills with huge metal grills and ground anchors. General specification».