Systems and methods for controlling extraction of landfill gas from a landfill via a gas extraction system are provided herein. According to some aspects of the technology, there is provided site-level control methods for globally controlling one or more wells based on one or more characteristics of aggregate landfill gas collected from a plurality of wells at a gas output. According to some aspects of the technology, there is provided well-level control methods for locally controlling a first well based on or more characteristics of landfill gas collected from the first well. According to further aspects of the technology, there is provided hybrid control methods for making adjustments to a respective well based on both site-level and well-level control methods.

Systems and methods for controlling extraction of landfill gas from a landfill via a gas extraction system are provided herein. According to some aspects of the technology, there is provided site-level control methods for globally controlling one or more wells based on one or more characteristics of aggregate landfill gas collected from a plurality of wells at a gas output. According to some aspects of the technology, there is provided well-level control methods for locally controlling a first well based on or more characteristics of landfill gas collected from the first well. According to further aspects of the technology, there is provided hybrid control methods for making adjustments to a respective well based on both site-level and well-level control methods.

A system for extracting landfill gas from a landfill is provided. According to some embodiments, a control system for landfill gas extraction is provided. The control system uses a throttle to control flow of landfill gas extracted from the landfill. The throttle is actuated in use to vary the flow of gas between a well and a gas collection system, in accordance with a control algorithm that adjusts flow as a parameter in controlling gas extraction. The throttle is configured to ensure that there is at least some flow of landfill gas from the landfill to a gas output throughout operation. The extraction system provides an efficient system for landfill gas extraction, while mitigating a risk of creating undesired or unpleasant conditions and/or of violating regulations during operation.

A coffin is provided, and the coffin includes a coffin body with a top opening and a coffin lid for closing the coffin body. The coffin lid is provided with an air intake hole and an exhaust air hole, the air intake hole and the exhaust air hole are respectively connected to an air intake device and an exhaust air device through pipelines to supply the oxygen required for decomposition of a body and exhaust waste gases. The coffin lid is further provided with an exhaust liquid pipe connected to a peristaltic pump. An oxygen or carbon dioxide sensor, and a hydrogen sulfide or ammonia concentration sensor are installed in an exhaust channel. The coffin body includes a plastic waterproof bag, and the coffin lid is pasted with adhesive plastic film. The function of the plastic waterproof bag is to prevent waste liquids from polluting the coffin body.

A bund system for the retention of solid or liquid or pourable waste material; bunds of the bund system comprising retaining structures; the retaining structures including at least one vertical structural element relative a base; the base covering a portion of a ground surface; the bunds maintained in a selected position on the ground surface by interaction of the retaining elements with a mass of compacted material.

Also disclosed is a method of forming a waste retention area by enclosing the waste retention area by bunds; the bunds comprising at least one substantially vertical retaining structure relative a base extending over a portion of a ground surface; the method including the steps of; positioning retaining structures on the ground surface to form an enclosed area; horizontal base panels of the retaining structures facing inwards to the enclosed area, welding overlap portions of sealing elements at adjacent vertical and horizontal joints between adjoining retaining structures, placing an impervious liner over the ground surface of the enclosed area, welding edges of the impervious liner to edges of sealing elements at inward edges of the horizontal base panels.

A bio-barrier for reducing combustible gas emissions from the ground into the atmosphere is disclosed. The bio-barrier includes a geocomposite layer extending laterally beneath a top surface of the ground and a first geotextile layer extending laterally beneath the top surface of the ground and positioned above the geocomposite layer. The geocomposite layer and the geotextile layer configured to laterally disperse the combustible gas through at least the geotextile layer. In addition, at least one sensor may be positioned beneath the top surface of the ground and in or above the geocomposite layer, the at least one sensor measuring a parameter indicative of the concentration or oxidation of the combustible gas beneath the top surface of the ground.

A cover system for preventing water ingress having a geomembrane layer and a wind-disturbing open-pore layer thereon and defining an asperity extent, said open-pore layer for forming in situ an air-flow turbulence zone between the geomembrane layer and a boundary space proximate the open-pore layer as a transition from turbulent flow of wind in the turbulence zone to laminar flow of the wind remote from the geomembrane layer, said open-pore layer inducing disturbance of a wind flow into and through the layer, whereby a suction force on the geomembrane is disturbingly broken by turbulent wind shear events therein and exerted downward pressure deflections, wherein the wind speed and pressure differential lessen and the geomembrane resists uplift. A method of covering a large area surface with a cover system that resists wind uplift is disclosed.

The present disclosure discloses a design method of a soil cover layer of a solid waste landfill considering the effect of plant root, which relates to the field of designing a soil cover for a solid waste landfill and aims to solve the problem of the prior art that does not consider the non-linear spatial variation of water content and the effect of plant root on the gas migration process. By comprehensively considering the type of plant root architecture, the distribution of water content varying with space, the errors of calculating gas migration caused by assuming that the water content of the cover layer is constant and ignoring the effect of plant root is effectively reduced; and the actual environment of the on-site cover layer is more comprehensively considered, thus improving the calculation accuracy.

A control system for controlling extraction of landfill gas from a landfill via a gas extraction system, the gas extraction system comprising well piping for coupling a plurality of wells to a gas output. The control system comprises a controller configured to: obtain a value indicating measured energy content of landfill gas collected at the gas output from the plurality of wells; determine whether the measured energy content is different from a target energy content; and in response to determining that the measured energy content is different from the target energy content: control a plurality of valves disposed in the well piping to change flow rates of landfill gas being extracted from at least some of the plurality of wells at least in part by changing degrees to which the plurality of valves are open.

A method for converting municipal solid waste to a stable solid fill-material (backfill) in the form of a multiplicity of compacted pieces, the method including mechanically reducing solid-waste piece size to form a solid-waste stream, heating the solid-waste stream and thereby killing bacteria in such stream, adding an antimicrobial agent to the solid-waste stream, and pelletizing the solid-waste stream.