轻质油污染土壤及地下水的生物修复强化技术

On enhanced methods for bio-remediating slightly hydrocarbon-contaminated soil and groundwater system

综述了土壤 -地下水系统中轻油污染物生物修复强化技术(生物通风、生物喷射和生物啜食 )的研究进展 ,对它们各自的基本原理、研究背景、工程应用及影响因素等做了比较详细的介绍。我国的研究现状是 。

This paper presents an introduction to the enhanced bioremediation methods (such as bioventing, biosparging and bioslurping) in bio-treating the contaminated soil and groundwater system with a review of the specific principles, application backgrounds and influencing factors in the field. Bioventing is an in situ remediation method that is used for the indigenous microorganisms to biodegrade organic constituents adsorbed by the soil in the unsaturated zone. The indigenous bacteria can be used to activate the soil and enhance the air (or oxygen) flow in the unsaturated zone (by means of extraction or injection wells) or by adding nutrients (if necessary). However, bioventing can only be used to activate the unsaturated-zone soil and increase low air flow rate to provide enough oxygen for sustaining the microbial activities. As to the bioventing, the influencing factors can be found, for instance, the size and amount of the contaminant, soil pH, nutrient levels, moisture, and so on. Whereas biosparging can be used to reduce the concentration of the petroleum constituents that are dissolved in the groundwater, adsorbed by the soil below the water table and within the capillary fringe, and therefore, it is most frequently used for the sites polluted with petroleum products (such as diesel fuel, jet fuel). Both site and constituent features may affect the biosparging features, such as intrinsic permeability, soil structure and stratification, temperature of the groundwater, microbial population density, contaminant's concentration and toxicity, chemical structure and so on. Since bioslurping may involve simultaneous application of vacuum enhanced extraction, vapor extraction, bioventing can just be addressed to LNAPL contamination. Moreover, the vacuum extraction is just used to remove the free products laden in some groundwater. As to the vapor extraction, its use is just to remove high volatility vapors from the vadose zone. Last of all, it is to mention bioventing, which is only to enhance aerobic biodegradation in the vadose zone and capillary fringe to promote the removing of LNAPL as a recoverable phase, and in turn be able to treat vadose soil layer to remove LNAPL in some system.