Purification method of polluted soil

Abstract

Provided is an engineering method for cleaning contaminated soil by which the problem of the cleaning method such as a washing method can be dissolved, content of contaminants in soil is suppressed below a standard and further elution quantity can be suppressed below a standard. The engineering method for cleaning the contaminated soil comprises a washing process in which contaminated soil with heavy metals is washed and is separated into washing muddy water and washing treated soil and a soil stabilizing process in which elution components of heavy metals from the washing treated soil are fixed. Preferably, the washing muddy water separated in the washing process is then separated into treated water and heavy metal-containing solid in a water treating process.

Description

technical field [0001] The present invention relates to a purification method of polluted soil, in more detail, it relates to a purification method of washing harmful heavy metals contained in soil, further realizing insolubility, stabilizing and harmless polluted soil. Background technique [0002] In Japan's Soil Pollution Countermeasures Law, heavy metals such as cadmium, lead, hexavalent chromium, arsenic, total mercury, copper, and selenium (a general term for metals with a specific gravity exceeding 4) are defined together with cyanide, fluorine, and boron. It is a Class 2 specific hazardous substance and is subject to restrictions. [0003] In this law, regarding heavy metals, etc., two standards are introduced from the perspective of the risk to the human body through direct ingestion and the risk to the human body through ingestion through groundwater, etc., and the former is defined as soil content, and the latter is defined as soil dissolution. . [0004] So far...

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Problems solved by technology

[0012] (2) Difficult to apply to polluted soil with more than 30% of fine particles such as silt and clay

[0014] (4) Due to the removal of silt, clay and organic matter, soil properties are lost and cannot be reused

[0015] In addition, due to the increase in the loss rate, even if the chemical reagent (acid) and washing liquid are used to extract and remove, the amount of dissolution will increase due to the influence of the remaining chemical reagent (acid), etc.

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