Horizontal well injection repairing method and device for shallow organic pollution site

Abstract

The invention provides a horizontal well injection repairing method and device for a shallow organic pollution site. The method comprises the following steps: 1, burying a prefabricated horizontal well in a pollution area, arranging a plurality of vertical pipes without sieve pores in the length direction of the horizontal well, connecting the bottom ends of the vertical pipes with the horizontal well in a sealing manner, and connecting the other top ends of the vertical pipes with a medicament injection unit; and 2, alternately injecting ahydrogen peroxide and sodium persulfate mixed solution and a sodium hydroxide and sodium persulfatemixed solution into the vertical pipe. In the in-situ injection process of the horizontal well, injection short flow caused by formation difference is reduced, and underground water flows to accelerate agent diffusion, so that the remediation agent can be in full contact with a polluted area, the oxidation efficiency in the reaction process is improved, and agent and pipe waste is reduced; and a double-activation oxidation system is formed by alternately injecting the sodium persulfate and hydrogen peroxide mixed solution and the sodium persulfate and sodium hydroxide mixed solution, the oxidation effect is improved, and the physical and chemical properties of soil are improved.

Description

technical field [0001] The invention relates to a restoration method for shallow (depth less than 6m) organic (especially SVOCs) polluted soil and groundwater, and belongs to the field of soil and groundwater restoration. Background technique [0002] In some polluted sites surrounded by densely populated residential areas, large-scale excavation will generate large secondary pollution, affect the normal life of surrounding residents, and easily cause complaints and social stability maintenance issues. In addition, it is not convenient to carry out large-scale excavation if the surrounding area of ​​the polluted area is close to important buildings or production workshops in operation. [0003] In-situ injection chemical oxidation is widely used in the treatment of organic polluted sites due to its advantages such as wide application range, simple operation, economical price and short repair period. At present, vertical well injection is generally used for in-situ injection...

AI Technical Summary

Problems solved by technology

At present, vertical well injection is generally used for in-situ injection chemical oxidation, but the construction of vertical wells will penetrate uneven geological formations, and injection priority channels will be formed during the injection process, resulting in a short flow of chemical diffusion and inability to effectively contact the contaminated area. The repair effect is not good, and more medicine needs to be injected to supplement, resulting in waste of medicine

In addition, the impact radius of vertical well injection is small, the density of injection wells built on the site is very high, and the amount of pipes and other materials is large

[0004] At present, alkali-activated persulfate is usually used as an oxidizing agent, which has a good oxidation effect, but it is easy to cause high soil alkalinity, change the physical and chemical properties of the soil, and affect the subsequent use of the soil.

Images