Light oil polluted unsaturated zone soil in-situ remediation apparatus and method thereof

Abstract

The invention relates to a light oil polluted unsaturated zone soil in-situ remediation apparatus and a method thereof. The apparatus comprises an underground well group system, a pipeline system and a ground processing system. The underground well group system comprises an extraction well, an injection well and a ventilation monitoring well. The ground processing system comprises: an oil gas extracting and processing module which comprises a vacuum pump, an oil-gas separation tank and an oil gas adsorption tank, wherein the inlet of the oil-gas separation tank is connected with the extraction well, the outlet of the oil-gas separation tank is connected with the inlet of the oil gas adsorption tank, and the outlet of the oil gas adsorption tank is communicated with the atmosphere; a microbial enhanced remediation module which comprises a microbe and nutrient solution preparation tank, wherein a first injection solution is contained in the microbe and nutrient solution preparation tank, the microbe and nutrient solution preparation tank is connected with the inlet of a first injection metering pump, and the outlet of the first injection metering pump is connected with the injection well; and a chemical oxidation remediation module which comprises a chemical oxidant preparation tank, wherein a second injection solution is contained in the chemical oxidant preparation tank, the chemical oxidant preparation tank is connected with the inlet of the second injection metering pump, and the outlet of the second injection metering pump is connected with the injection well.

Description

technical field [0001] The invention relates to the field of environmental protection, in particular to an in-situ remediation device and method for light oil-polluted unsaturated zone soil at gas stations, which combines "soil gas phase extraction", "microbial enhanced degradation" and "chemical oxidation Degradation" and other functions. Background technique [0002] Soil oil pollution often has the characteristics of many types of pollutants, long incubation period, wide diffusion area, great harm, complex underground structure, difficult treatment, and high repair cost. If soil pollution cannot be effectively controlled now, it may further deteriorate in the future, threatening the ecological environment and human health. The development of on-site remediation methods and equipment for oil-contaminated soil has become an urgent need for environmental protection at this stage. [0003] Statistical analysis shows that the leakage of underground oil storage tanks (USTs) i...

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Problems solved by technology

Chemical oxidation injects oxidants into the soil, and the pollutants are degraded through chemical reactions; compared with other remediation methods, chemical oxidation can quickly degrade petroleum hydrocarbon pollutants, and if the reaction time is sufficient, the pollutants can be completely oxidized into CO2 and H2O, But there is also the disadvantage of high repair cost, which is more economical and effective for the degradation of low-concentration pollutants

Phytoremediation is to use the absorption, volatilization, transformation, degradation and other mechanisms of plants and their rhizosphere microbial system to remove pollutants in the soil environment; the cost of restoration is low, but the cycle is long, affected by the season, it is only suitable for surface soil restoration

[0008] Every soil pollution remediation method has its applicability, no matter what kind of remediation method, due to the differences in soil properties and pollution sources, it is difficult for a single soil pollution remediation method to achieve the purpose of removing all pollutants quickly, efficiently and economically. The restoration technology and equipment generally adopt a combination of various methods.

Invention patent CN102228900A discloses an in-situ comprehensive remediation system and method for oil-contaminated soil, which mainly uses two-phase vacuum suction combined with microbial stimulation to remediate the underground environment (mainly saturated zone soil) that is heavily polluted by the free phase. ;Because the extracted substances include oil phase, water phase, and gas phase, the ground treatment process is complicated

The equipment investment cost is high, the operating cost is high, and the explosion-proof level of the equipment has not been determined; it is not suitable for use in gas stations

Invention patent CN102580993A discloses an in-situ remediation technology of organic polluted soil, which mainly adopts steam heating-assisted soil gas phase extraction technology to remediate organic polluted soil, mainly consisting of steam generation and injection system, soil gas phase extraction system, ground waste gas and wastewater The composition of the treatment system; there are also problems such as complex equipment and process systems, high equipment investment costs, and high energy consumption in operation; the tail gas is treated by catalytic combustion, which is not suitable for on-site use at gas stations

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