A phytoremediation method for treating cadmium, lead, and arsenic compound polluted soil

Abstract

The invention provides a phytoremediation method for managing composite cadmium-lead-arsenic contaminated soil. The method comprises the following steps: step S1: selecting a cadmium-enriched castor-oil plant variety; step S2: obtaining cadmium-lead-arsenic composite contaminated soil with neutral acidity and alkalinity; step S3: planting cadmium-enriched castor-oil plants and ciliate desert-grass in an intercropping manner in the cadmium-lead-arsenic composite contaminated soil with neutral acidity and alkalinity for surviving and growth, and harvesting matured castor-oil plants at regular intervals, and carrying out step S5; step S4: harvesting the upper part of the ciliate desert-grass according to the growth height of the ciliate desert-grass, and carrying out the step S5; retaining stubble of the ciliate desert-grass on the soil surface, and carrying out the step S3; step S5: feeding the harvested and matured castor-oil plants and ciliate desert-grass to an exclusive place for concentration and carrying out innocent treatment. The invention further provides a phytoremediation method for managing cadmium contaminated soil. The phytoremediation method is suitable for managing and repairing cadmium-lead-arsenic moderately and slightly contaminated soil, and has good practical application prospect.

Description

technical field

[0001] The invention relates to the technical field of pollution control, in particular to a phytoremediation method for treating cadmium, lead and arsenic composite polluted soil. Background technique

[0002] At present, with the development of industry and agriculture and the acceleration of urbanization, the phenomenon of soil pollution by heavy metals is relatively common in some parts of my country, especially in some non-ferrous metal mining areas and surrounding areas of smelters. Among them, cadmium (Cd), lead (Pb), arsenic (As) is particularly serious, far exceeding the soil critical value in GB15618-1995 "Soil Environmental Quality Standards" to ensure agricultural and forestry production and normal plant growth. At present, about 25 million hectares of farmland soil is polluted by heavy metals in my country, and as many as 12 million tons of grain are polluted by heavy metals every year, causing direct economic losses of more than 10 billion yuan. ...

Examples

Embodiment Construction

[0027] In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0028] One. At first, introduce the centipede grass among the present invention:

[0029] Centipede grass is the earliest As hyperaccumulator plant discovered by Chen Tongbin's research team in the world. Centipede grass not only has strong tolerance and unique enrichment ability to As, but also has strong tolerance and enrichment effect to Pb. Field surveys show that centipede grass can grow in contaminated soil near slag with an As content of 23400 mg / kg and lead-zinc tailings with a lead concentration as high as 3368-3550 mg / kg. Centipede Grass has strong arsenic tolerance, arsenic enrichment ability and fast arsenic absorption rate. In the soil with arsenic content <1000mg / kg, the bioconcentration factor (the ratio o...

technical field

[0001] The invention relates to the technical field of pollution control, in particular to a phytoremediation method for treating cadmium, lead and arsenic composite polluted soil. Background technique

[0002] At present, with the development of industry and agriculture and the acceleration of urbanization, the phenomenon of soil pollution by heavy metals is relatively common in some parts of my country, especially in some non-ferrous metal mining areas and surrounding areas of smelters. Among them, cadmium (Cd), lead (Pb), arsenic (As) is particularly serious, far exceeding the soil critical value in GB15618-1995 "Soil Environmental Quality Standards" to ensure agricultural and forestry production and normal plant growth. At present, about 25 million hectares of farmland soil is polluted by heavy metals in my country, and as many as 12 million tons of grain are polluted by heavy metals every year, causing direct economic losses of more than 10 billion yuan. ...

Examples

Embodiment Construction

[0027] In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0028] One. At first, introduce the centipede grass among the present invention:

[0029] Centipede grass is the earliest As hyperaccumulator plant discovered by Chen Tongbin's research team in the world. Centipede grass not only has strong tolerance and unique enrichment ability to As, but also has strong tolerance and enrichment effect to Pb. Field surveys show that centipede grass can grow in contaminated soil near slag with an As content of 23400 mg / kg and lead-zinc tailings with a lead concentration as high as 3368-3550 mg / kg. Centipede Grass has strong arsenic tolerance, arsenic enrichment ability and fast arsenic absorption rate. In the soil with arsenic content <1000mg / kg, the bioconcentration factor (the ratio o...

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