Method for remediating cadmium contaminated soil of vegetable field in situ by compounding bio-charcoal and organic fertilizer

Abstract

The invention relates to a method for remediating cadmium contaminated soil of a vegetable field in situ by compounding bio-charcoal and an organic fertilizer. The method comprises the following steps of: applying a passivation material obtained by compounding the bio-charcoal and the organic fertilizer in a mass ratio of 1:1 to a surface layer of soil of a cadmium contaminated vegetable field, fully and uniformly mixing the passivation material and the soil in a plowing layer with the thickness of 0 to 20cm, judging the contamination level of the soil according to environmental quality standard for soils GB15618-1995, and ensuring that the application rate of the passivation material is not less than 0.5 percent of the weight of dry soil, namely 750kg / mu when the cadmium concentration of the soil is 1.0 to 2.9mg / kg. The invention has the advantages that: raw materials of the passivation material are wide in source and low in cost, the application method is simple and has a remarkable effect of remediating the cadmium in the soil in a passivation way, and the risk of secondary contamination is avoided; and the bio-charcoal is applied into the soil, so the passivation material has the effects of reducing the discharge of greenhouse gas of farmland ecosystems, increasing the content of organic carbon of the soil, improving soil structures and the like, and has huge popularization and application value.

Description

technical field [0001] The invention relates to heavy metal polluted soil treatment technology, in particular to a method for repairing cadmium (Cd) pollution in vegetable field soil in situ by compounding biochar and organic fertilizer. technical background [0002] Heavy metal pollution is an important class of pollutants in agricultural soil environment and agricultural products. The area of ​​cultivated land polluted by heavy metals in my country exceeds 20 million hm 2 More than 1 / 5 of the cultivated land area. 1.4 million hm in our country 2 In the sewage irrigation area, 64.8% of the land was polluted by heavy metals, of which 46.7% were slightly polluted, 9.7% were moderately polluted, and 8.4% were severely polluted. Cd, Hg, Pb, As, Cu, etc. in grains and vegetables are seriously and commonly exceeded, causing huge economic losses to agriculture. my country produces about 12 million tons of grains polluted by heavy metals every year. Among the 320 key pollution ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide an economical, high-efficiency, stable and safe method for in-situ restoration of cadmium-polluted vegetable soil in view of the technical problems of soil heavy metal pollution control.

Images