Remediation method of heavy metal contaminated soil

Abstract

The invention discloses a remediation method of heavy metal contaminated soil. The remediation method comprises the steps of applying humic acid on the surface of the heavy metal contaminated soil, turning and evenly mixing the soil with a thickness of 20-30 cm from the contaminated soil surface layer with the humic acid, reacting for 7-15 days and then pre-burying leaching device under a contaminated area of the heavy metal contaminated soil; leaching the soil by using a citric acid solution and a tea saponin solution in sequence through the leaching device, and recycling leaching liquid of the leaching device and leaching liquid containing heavy metals to process intensively after finishing leaching; then applying fruit residues on the soil surface, turning and evenly mixing the fruit residues with the soil with a thickness of 20-30 cm from the soil surface layer, intercropping sunflowers and brassica juncea, harvesting all the biomasses on the ground after the plants are ripe to process intensively. Due to the adoption of the method, high removal rates of various heavy metal ions in the soil are achieved; the soil is remediated completely; meanwhile, the method is low in cost, good in effect and easy to implement.

Description

technical field [0001] The invention relates to a repair method for heavy metal polluted soil. Background technique [0002] The traditional chemical leaching method to repair soil heavy metal pollution will destroy the structure of the soil itself and make the soil difficult to recycle. Some leaching agents are difficult to biodegrade and will cause secondary pollution to the soil. Some leaching agents are expensive and cause The leaching method is difficult to popularize and apply in engineering. Some scholars use humic acid and activated sludge to treat heavy metal-contaminated soil, which can improve the secondary pollution of soil caused by leaching agents, but at the same time there is a problem of complex domestication conditions of activated sludge. Tea saponin and citric acid have the characteristics of biodegradability and no secondary pollution. Some scholars have studied the repair effect of single leaching of tea saponin and citric acid on soil heavy metals, bu...

AI Technical Summary

Problems solved by technology

[0002] The traditional chemical leaching method to repair soil heavy metal pollution will destroy the structure of the soil itself and make the soil difficult to recycle. Some leaching agents are difficult to biodegrade and will cause secondary pollution to the soil. Some leaching agents are expensive and cause The washing method is difficult to popularize and apply in engineering

Some scholars use humic acid and activated sludge to treat heavy metal-contaminated soil, which can improve the secondary pollution of soil caused by leaching agents, but at the same time, there is a problem of complex domestication conditions for activated sludge.

Tea saponin and citric acid have the characteristics of biodegradability and no secondary pollution. Some scholars have studied the repair effect of single leaching of tea saponin and citric acid on soil heavy metals, but a single leaching agent has the effect of compounding multiple heavy metals. The remediation of contaminated soil has limitations, and the commercially available tea saponin is expensive, although it is environmentally friendly, it is difficult to popularize and apply

At the same time, the eluent containing heavy metal pollution still exists in the soil and has not been completely removed, posing certain safety hazards

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