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.

The disclosure provides a soil-groundwater joint remediation device and a method. The soil-groundwater joint remediation device is disposed in an area to be remediated and includes an injection structure, an extraction structure, and a control structure. The injection structure is disposed in an injection well defined in the area to be remediated. The injection structure includes a hot air injection member, an oxidant injection member, and a micro-bubble injection member. The extraction structure is disposed in an injection well defined in the area to be remediated and spaced from the injection structure. The extraction structure includes a liquid phase extraction member and a gas phase extraction member. The control structure controls the liquid phase extraction member and the gas phase extraction member to perform an extraction operation.

The present invention relates to an apparatus for treating waste containing mercury and a method for recovering high purity elemental mercury using the apparatus. More specifically, the present invention may provide a method that can more economically and stably recover high purity elemental mercury from waste containing mercury using an apparatus for recovering mercury from waste containing mercury, the apparatus comprising: a thermal desorption unit; a dust control unit; and a condensation and recovery unit, which are connected in series. The present invention has an advantage in that, compared to a conventional simple heat treatment-condensation method, a high recovery rate of mercury is achieved and high purity mercury can be obtained.

A low-profile fluid collection conduit includes an elongate outer cover having an upper portion and a lower portion generally opposite the upper portion, with the outer cover being much wider than it is tall and defining an interior volume. An elongate rigid spacer is fitted within the interior volume of the elongate outer cover, with the elongate spacer allowing the majority of the interior volume to be unfilled so as to permit the flow of fluid along and within the elongate outer cover. The collection conduit is used with a fluid-impermeable membrane as part of a landfill fluid collection and conveyance system.

A system for covering various types of ground where water and wind erosion protection are needed comprises a composite of at least one geotextile tufted or knitted with synthetic yarns (forming a synthetic turf), an open grid mesh, and a geo-filter (filter fabric). The filter fabric is positioned in direct contact with the ground surface, the open grid mesh is positioned over the filter fabric, and the synthetic turf is positioned over the open grid mesh. The system provides a beneficial erosion protection that does not require maintenance and can be used to cover slopes without requiring vegetative support and/or a topsoil layer. An optional sand layer can be placed atop the synthetic turf as desired as infill to ballast the material and protect the system against wind uplift.

A low-profile fluid collection conduit includes an elongate outer cover having an upper portion and a lower portion generally opposite the upper portion, with the outer cover being much wider than it is tall and defining an interior volume. An elongate rigid spacer is fitted within the interior volume of the elongate outer cover, with the elongate spacer allowing the majority of the interior volume to be unfilled so as to permit the flow of fluid along and within the elongate outer cover. The collection conduit is used with a fluid-impermeable membrane as part of a landfill fluid collection and conveyance system.

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 treating a contaminated soil. The system includes a soil receptacle, a first conveyance mechanism in communication with the soil receptacle, and a second conveyance mechanism in communication with the first conveyance mechanism. The second conveyor is placed lower relative to the first conveyor so that the contaminated soil drops in elevation as it passes from the first conveyor to the second conveyor. One or more pretreatment sprayers are positioned substantially at a junction between the first conveyor and the second conveyor and that spray the contaminated soil as it moves from the first conveyor to the second conveyor. One or more sprayers are also positioned on the second conveyor such that they can spray the contaminated soil as it passes. An aerator is located at a depositing end of the second conveyor, by which the contaminated soil is further aerated as it drops of the depositing end of the second conveyor and contacts the aerator. One or more optional final sprayers can be positioned on the second conveyor such that they are able to spray the contaminated soil as it drops off the depositing end and contacts the aerator.

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.

Described herein are embodiments of a control system that automatically (1) determines whether a gas extraction system is in a state in which landfill gas is being released into the atmosphere, and (2) automatically controls landfill gas flow to mitigate, prevent and/or stop the release of landfill gas. The control system may control a valve to control flow of landfill gas through well piping of the gas extraction system. The pressure of landfill gas in the well piping at a location upstream of the valve may indicate whether there is a risk of landfill gas being released into the atmosphere. The control system may adjust a position of the valve in response to determining that the pressure at the location upstream of the valve indicates that there is a risk of landfill gas being released into the atmosphere.