Restoration method for northern industrial and mining wasteland heavy metal pollution

Abstract

The invention provides a restoration method for northern industrial and mining wasteland heavy metal pollution, and relates to the technical field of soil restoration. The restoration method is characterized in that impurities, weeds, garbage and the like in a to-restored area are removed, flattening treatment is performed for enabling gradient to be smaller than 25 degrees, polluted soil is excavated with excavation depth being 40-60 cm; a layer of HDPE impermeable membrane spreads on the bottom of a foundation pit; a stabilizer is added into temporarily stored polluted soil to mix; the mixedoil is backfilled onto the impermeable membrane; a layer of nutrient substrate with a thickness being 4-7 cm is sprayed and distributed on the upper layer of the backfilled soil; the stabilizer is prepared from 2-10% of shell powder, 3-12% of a calcium magnesium phosphate fertilizer, and 1-9% of carboxymethyl chitosan; and the nutrient substrate layer consists of the following components in volume ratio: 10-24% of clay, 10-18% of perlite, 9-24% of plant fibers, 8-15% of montmorillonite, 1-5% of a controlled-release compound fertilizer, 20-40% of organic matters, 0.35-0.38% of an aggregate agent, and 0.5-3% of seeds; and the seeds are one or more of nitraria tangutorum bobr, haloxylon ammodendron, hedysarum scoparium, caragana korshinskii, medicago sativa and lespedeza. The restoration method adopts a curing-plant enriching combined restoration technology, and has the beneficial effect of fixing heavy metals in the soil.

Description

technical field [0001] The invention provides a restoration method for heavy metal pollution in industrial and mining abandoned land in northern China. The target heavy metal pollutants are lead, zinc and cadmium, and relates to the technical field of soil pollution restoration. Background technique [0002] With the continuous development of the global economy, heavy metal pollution in soil has become a major problem facing the global environmental quality. Heavy metals in soil come from a wide range of sources, mainly from various wastes discharged from human production activities, such as mining, smelting and waste electronic products. Treatment, etc., as well as agricultural chemical fertilizers (unreasonable use) and pesticides, radioactive substances, etc. Heavy metal pollution is concealed, long-term, and irreversible. It cannot be decomposed by plants or microorganisms, eventually leading to soil degradation and crop yield reduction. It enters the human body through ...

AI Technical Summary

Problems solved by technology

However, if the stabilization technology is used alone, adding too much stabilizer will have a great impact on the physical and chemical properties of the soil, which will make it difficult for soil microorganisms and plants to survive; insufficient stabilizer dosage will not make the soil biologically stable. The heavy metals in the active form are all stable, and it is difficult to achieve a good treatment effect

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