Contaminated soil organized seepage in situ forced purification method

Abstract

A contaminated soil organized seepage in situ forced purification method comprises the following steps: arranging vertical waterproof curtains at the periphery of contaminated sites to isolate and avoid seepage, excavating seepage channels, excavating water collecting wells, preparing leaching solution, and leaching contaminated soil. The method adopts seepage open channels to divide contaminated site leaching units and overcomes the shortcoming that difference of soil quantity of large-area contaminated sites is large so as to result in an unstable leaching effect. The contaminated soil organized seepage in situ forced purification method adopts layered excavating of main open channels, branch open channels and water collecting channel, thereby shortening vertical seepage distance of leaching solution and reducing excavated volume of contaminated site soil during construction. The leaching solution performs submerging, immersing, seepage and leaching in layered mode, thereby promoting sufficient reaction between the leaching solution and contaminant. By means of re-purification of remained contaminant in soil layers after leaching through subsequent leaching, residual quantity of the contaminant in soil is greatly reduced, leaching effect is improved, operation is convenient and fast, controllability of the contaminant is strong, and actual engineering quantity is small.

Description

technical field [0001] The invention relates to an in-situ forced purification method of organized seepage of polluted soil, belonging to the technical field of polluted site remediation. Background technique [0002] In the process of my country's continuous urbanization, major cities have re-planned their strategic layout, and a large number of factories (especially those with high pollution and high energy consumption such as chemicals, pesticides, and metallurgy) that were originally located on the edge of the urban area or in the suburbs have been relocated. For the many polluted sites left by the relocation of enterprises, the land use is greatly restricted and there is a great potential threat. Soil pollutants in contaminated sites are mainly divided into three categories: organic pollutants, heavy metal pollutants and radioactive pollutants. [0003] my country only started the national soil pollution system survey in 2006. The experience in soil pollution control is...

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Problems solved by technology

[0003] my country only started the national soil pollution system survey in 2006. The experience in soil pollution control is seriously insufficient, the relevant laws and regulations are lacking, and the detection and repair technology and equipment are backward.

Current contaminated soil treatment technology and treatment engineering experience show that there are still major problems such as high treatment costs and long periods of time.

Among the numerous soil remediation technologies for contaminated sites, the in-situ leaching remediation technology, as a technology with better pollutant control effect, has been vigorously promoted and applied to a certain extent in the United Kingdom, the United States and other places, but it has not yet been applied in my country.

[0004] When the existing in-situ leaching technology is used for leaching the polluted site, the seepage channel is excavated only once, and the shape is regular and all connected. The distribution of the amount of washing solution varies greatly, the area covered by the washing solution on the contaminated site is small, and there are many areas where there are leaked washing areas in the contaminated site, resulting in poor washing effect

The water collection well is set to form a hole at one time, which mainly relies on the seepage between well points to leach pollutants, which is greatly affected by the distribution characteristics of soil permeability, and it is easy to cause blank areas of seepage, and the phenomenon of leakage and leaching is serious

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