Apparatus is disclosed for separating an amount of a substance from groundwater, comprising an elongate chamber (18) having an inlet (22) which is arranged in use to admit groundwater into the chamber near a lower first end (24). There is also a gas sparger (26) located near the first end (24) which admits gas into the chamber for inducing groundwater to flow from the first end (24) of the chamber toward a second end upper end, and for producing a froth layer (32) which rises above an interface with the groundwater including a concentrated amount of the substance. A suction hood (38) can be moved downward from the top of the chamber (18) into a position to collapse the froth layer (32) and to cause it to be removed from the well body (14). The suction hood (38) (acting as a froth depth regulation device) controls the amount of groundwater in the froth layer (32), which influences the concentration of the contaminant substance achieved in the froth layer (32).

Disclosed is an electrokinetic-aeration-liquid injection combined remediation method for compound contaminated soil containing heavy metals and organic substances, and belongs to the field of contaminated soil remediation. According to the present application, in the combined remediation method, the electrokinetic remediation method enables water in soil to migrate from bottom to top to drive heavy metals and organic substances to be enriched towards the top; bubbles generated by the aeration method are diffused from the bottom to the top to drive volatile organic compounds to move towards the top soil. During liquid injection process, the electrolyte is driven to move from bottom to top under the action of electrokinetic remediation flow, which can keep the pH of the soil stable and remediate heavy metals and organic pollutants. The whole processes are simultaneously completed by adopting the dual-channel porous EKG electrode designed by the present application, which is efficient and convenient.

The present invention discloses a nonhomogeneous soil pollutant multiphase extraction and tail gas purifying device and an application method thereof. The device comprises two water retaining walls, a water layer extraction system and a near-water soil layer extraction system, a nonhomogeneous soil layer extraction system and a geophysical prospecting system, etc. The distribution of pollutants and the range of the pollution plume can be determined through geophysical prospecting, borehole exploration, three-dimensional simulation, etc.; through the combined application of the water retaining wall and the water pumping and supplementing self-circulation system, it is beneficial to form a stable treatment area for the occurrence area of the groundwater layer; the arrangement of the water layer extraction system facilitates the liquid extraction of the organic pollutants in a free phase and a dissolved phase at the groundwater.

Disclosed is an electrokinetic-aeration-liquid injection combined remediation method for compound contaminated soil containing heavy metals and organic substances, and belongs to the field of contaminated soil remediation. According to the present application, in the combined remediation method, the electrokinetic remediation method enables water in soil to migrate from bottom to top to drive heavy metals and organic substances to be enriched towards the top; bubbles generated by the aeration method are diffused from the bottom to the top to drive volatile organic compounds to move towards the top soil. During liquid injection process, the electrolyte is driven to move from bottom to top under the action of electrokinetic remediation flow, which can keep the pH of the soil stable and remediate heavy metals and organic pollutants. The whole processes are simultaneously completed by adopting the dual-channel porous EKG electrode designed by the present application, which is efficient and convenient.

A closed-loop system and method for heating of target contaminant zones having environmental contaminants of concern present in the groundwater and the soil by thermal conduction, and subsequent enhancements of physical, biological and chemical processes to attenuate, remove and degrade contaminants in the target contaminant treatment zones, is disclosed. The system and method collects solar or other heat and transfers the heat via a closed-loop and a set of borehole exchangers to subsurface soil in the proximity of and/or directly to the target contaminant treatment zones. The target contaminant treatment zone may comprise contaminated soil, contaminated groundwater in an aquifer, or industrial waste comprising water and/or solids. Solar collectors or heat exchangers capturing waste heat from industrial processes may be used as the heat source.

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.

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.

The present invention discloses a nonhomogeneous soil pollutant multiphase extraction and tail gas purifying device and an application method thereof. The device comprises two water retaining walls, a water layer extraction system and a near-water soil layer extraction system, a nonhomogeneous soil layer extraction system and a geophysical prospecting system, etc. The distribution of pollutants and the range of the pollution plume can be determined through geophysical prospecting, borehole exploration, three-dimensional simulation, etc.; through the combined application of the water retaining wall and the water pumping and supplementing self-circulation system, it is beneficial to form a stable treatment area for the occurrence area of the groundwater layer; the arrangement of the water layer extraction system facilitates the liquid extraction of the organic pollutants in a free phase and a dissolved phase at the groundwater.

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.