Method and system for efficient filter pressing and drip washing of contaminated soil and control method

Abstract

The invention discloses a method and system for efficient filter pressing and drip washing of contaminated soil and a control method. The method for repairing heavy metal contaminated soil comprises the following steps that firstly, the pulp smelting and acidification reaction is carried out; secondly, a sizing agent obtained after the sufficient reaction is filtered to obtain a soil filter cake and filter liquor; thirdly, pre-drip washing is carried out, heavy metal left in capillary holes in the filter cake is replaced and washed out; fourthly, after pre-drip washing is carried out, an eluting agent is injected in a washing reaction type membrane press filter step by step to carry out the multi-stage drip washing reaction; fifthly, after the drip washing reaction is carried out, dissociative heavy metal left in the soil filter cake can be stabilized, tiny heavy metal particles formed in the stabilization process are moved out of the soil, the input pressure ranges from 0.22 MPa to 0.35 MPa, and the vulcanization drip washing amount accounts for 50-80% of the total water content of the soil; and sixthly, the soil is stabilized. The problem that in the drip washing process in the prior art, leacheate is left in the soil, and consequently the soil leaching toxicity heavy metal index exceeds the standard is solved.

Description

technical field [0001] The invention relates to a method, system and control method for high-efficiency pressure filtration and leaching of polluted soil, belonging to the field of environmental restoration. Background technique [0002] With the rapid development of my country's economy, resource-based minerals have been exploited rapidly, and mining, metallurgy, and chemical companies have launched one after another. Due to relatively backward environmental protection measures and inadequate supervision, the pollution of industrial sites and surrounding soil and groundwater has become increasingly serious. A series of environmental pollution incidents; at the same time, with the acceleration of urbanization and people's increasing sensitivity to environmental pollution, the restoration and reuse of heavy metal-contaminated soil has become one of the most urgent environmental issues. Due to the characteristics of long-term, concealment and irreversibility of heavy metal poll...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the defects existing in the existing soil leaching repair technology, the present invention aims to provide a method and system for high-efficiency pressure filtration leaching contaminated soil, which can effectively solve the problem of leaching in the prior art leaching process. The residual liquid in the soil leads to the problem that the index of soil leaching toxic heavy metals exceeds the standard and the problem of secondary pollution of the soil by the residual leaching agent in the soil. Further, the present invention can solve the problem of freeing the residual soil with a stabilizer after leaching. When heavy metals are converted into solid phases, tiny particles will enter the liquid phase during leaching toxicity detection, resulting in excessive heavy metal indicators. Furthermore, the present invention can also control the amount of rinsing water from the source to reduce the waste of rinsing agents and recycle the rinsing agents. cost issue

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