Chemical washing-plant absorbing combined repair method for cadmium heavy pollution acid soil of non-ferrous metal mining area of south China

Abstract

The invention discloses a chemical washing-plant absorbing combined repair method for cadmium heavy pollution acid soil of a non-ferrous metal mining area of south China. The method comprises the following steps: grinding and sieving heavy metal polluted soil and filling the ground and sieved heavy metal polluted soil into an earth pillar; pouring a solution of ferric chloride into the upper part of a soil body, so that the solution flows out from the bottom of the earth pillar naturally along with the gravity, and most part of active cadmium can be removed; after a washing liquid in the upper part of the soil body completely seeps into the soil, pouring deionized water into the upper part of the soil body, so that the liquid flows out from the bottom of the earth pillar naturally along with the gravity, and residual cadmium and washing agent are removed; drying, grinding and sieving the washed soil; adding quicklime, sepiolite, a commercial organic fertilizer and the 0.2 to 1.2 g kg<-1> of total nutrient (N+P2O5+K2O) for improvement; continuously planting sedum plumbizincicola for 1 to 5 seasons, and harvesting over-ground parts to complete repair.

Description

technical field [0001] The invention relates to the treatment technology of heavy metal polluted soil, in particular to a chemical leaching-plant absorption combined restoration method for cadmium heavily polluted acidic soil in non-ferrous metal mining and metallurgy areas in southern China Background technique [0002] In recent decades, with the rapid development of industrialization and urbanization in my country, the problem of soil heavy metal pollution has become increasingly prominent. There are a large number of heavy metal heavily polluted soils around non-ferrous metal mining and metallurgy areas, among which cadmium pollution is one of the most concerned issues. Heavy metals have the characteristics of long residual time, strong concealment, and high toxicity. Heavy metals cannot be degraded by microorganisms and begin to accumulate once they enter the environment, threatening human health through dust exposure or food chain transmission. Most of the soil in so...

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Problems solved by technology

The invention overcomes the problem of low removal rate of heavy metals in the later stage of simple chemical leaching and the shortcoming of long period of simple plant absorption and restoration on heavily polluted soil, can greatly reduce the amount of leaching agent and rinsing water, and reduce the plant absorption and restoration cycle, restoration cost and environmental protection. risk

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