Method and system for contaminant removal by injecting high-temperature dry gas into soil

Abstract

The invention discloses a method for contaminant removal by injecting high-temperature dry gas into soil. The method includes the following step: (1), preparing the high-temperature mixed dry gas by a high-temperature mixed gas injector; (2), injecting the high-temperature mixed dry gas prepared in the step (1) into a dry gas injection well deep in contaminated soil; (3), adjusting the temperature of the high-temperature mixed dry gas injected into the dry gas injection well and retention time of the high-temperature mixed dry gas in the dry gas injection well to enable heat energy to be diffused in soil layers to perform mixed-gas soaking; (4), after mixed-gas soaking is finished, refining gaseous contaminants subjected to catalytic pyrolysis to the ground by a contaminated gas refining well, recycling the gaseous contaminants by a contaminated gas recycling device, and pumping contaminants carried in condensate water generated after injection of the high-temperature mixed dry gas to the ground by a pumping well for treatment. The method has the advantages that the temperature of the injected high-temperature dry gas is high and volatile and nonvolatile organic matter and heavy metal contaminants in the contaminated soil can be removed.

Description

technical field [0001] The invention belongs to the technical field of soil remediation, and in particular relates to a method and system for injecting high-temperature dry gas into soil for flooding. Background technique [0002] The pesticide chemical plant includes methamidophos workshop, power workshop, sewage treatment area, methyl packaging workshop, ethyl workshop, emulsification workshop, ethyl packaging workshop, mixing area, hydrochloric acid tank area, chlor-alkali workshop, salt storage, caustic soda tank area, Machine repair workshops, office areas, etc. Pesticide chemical factories have been severely polluted by pesticides such as methamidophos, parathion trichloride, glyphosate, and chlorinated benzene due to the production of pesticides and chemical products for many years. There are organic phosphorus, Benzene and other pollution and heavy metal hazards such as arsenic, cadmium, and lead lead to serious soil pollution. If these pollutants remain in the soil...

AI Technical Summary

Problems solved by technology

If these pollutants remain in the soil, they will further enter the water body, the atmosphere and the food chain, which will cause great harm to the ecological environment and human health.

[0003] At present, there are many methods for the removal of pollutants in soil, such as post-excavation incineration, biological treatment, chemical additives or passivation, etc. Although these methods have been successfully used in some instances, they are expensive and have certain shortcomings, so Impractical in large-scale soil remediation

[0004] Chinese patent CN1586747A discloses an off-site treatment process and device for soil contaminated by volatile and semi-volatile organic compounds, but this patent mainly uses vacuum extraction method to only deal with volatile and semi-volatile organic pollutants. Non-volatile organic pollutants are difficult to remove

This patent requires the heating device to be deep underground, which is difficult to install and operate

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