Method of treating petroleum-polluted clay foundation by using multiple microflora

Abstract

A method of treating petroleum-polluted clay foundation by using multiple microflora is capable of achieving integration of soil recovery and soil reinforcing construction. The method includes the steps of: (a) preparing a microbial agent (1); (b) uniformly stirring the microbial agent (1) with soil (3) in to-be-processed stratum with a deep stirring machine (2) according to the mass ratio of 1:100, and then leveling the field; (c) arranging injection pipes (4) in a row in the field according to hole distance of 0.8 m; (d) injecting a nutrient solution (5) into the to-be-processed stratum through the injection pipes (4) every three days; (e) arranging detection holes in the field according to density of one hole per 200 m<2>, and withdrawing soil pore liquid from the detection holes everysix days and performing oil content measurement, when the oil content of the soil reduces by more than 80%, alternately injecting the nutrient solution (5) and a cementing solution (6) into the to-be-processed stratum through the injection pipes (4); and (f) when preset injection times is reached, detecting foundation strength and heavy metal concentration of the soil, if the indices satisfy requirements, removing the injection pipes (4), or if not, repeating the step (e) until the requirements are satisfied.

Description

technical field [0001] The invention relates to a method for treating petroleum-contaminated clay foundations with microbial compound flora, and belongs to the technical field of foundation treatment. Background technique [0002] The leakage of crude oil in the process of mining, production, and transportation has caused increasing concern about soil pollution, and its pollutants are mainly petroleum hydrocarbons and polycyclic aromatic hydrocarbons. Petroleum hydrocarbons are difficult to degrade in the environment. When they enter the soil, they will change the nutrient composition of the soil, affect the permeability of the soil, and cause crop death. The vast majority of aromatic hydrocarbons and their derivatives are carcinogenic and mutagenic, which seriously endanger human health. In addition, petroleum-contaminated soil also contains a variety of harmful heavy metals, which also pollute soil and groundwater. With the acceleration of urbanization in my country, the...

AI Technical Summary

Problems solved by technology

[0005] Technical problem: Due to the interaction between the electric double layer characteristics of clay mineral particles and microorganisms, as well as the compatibility of soil particle size, pore throat size and microbial individual size, microorganisms cannot freely migrate between the pores of clay bodies, and pass to the formation It is almost impossible to repeatedly inject microorganisms and nutrients rich in calcium ions and nitrogen sources to strengthen cohesive soil foundations. Therefore, the existing MICP technology mainly treats sandy soil and silt soil, and rarely involves clay soil.

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