The method that Pb pollutes in a kind of rehabilitating soilTechnical field
The present invention relates to a kind of heavy-metal contaminated soil in-situ remediation method, belong to the recovery technique field of heavy-metal contaminated soil.Specifically utilize heavy metal Pb the super enriching plant rough melic herb (Pogonatherum crinitum) method of repairing the Pb contaminated soil.
Background technology
China's heavy metal Pb contaminated soil area is big, coverage is wide, toxic action is hidden; And can not be decomposed by edaphon; Accumulate, be converted into the stronger methyl compound of toxicity easily, even can in human body, accumulate and the serious threat human health through food chain.Heavy metal Pb pollution control at present mainly adopts soil moved in to improve the original method, leaching method, use physics and chemical method such as chemical improvement agent, and these methods are expensive not only, can only small area applications, and cause secondary pollution easily, can not tackle the problem at its root.
On the soil that contains pollutant Pb, plant rough melic herb; Absorb the Pb in the contaminated soil in a large number through the rough melic herb root system; And it is transferred to the overground part organ; When plant length is maximum to the upperground part biomass, the plant shoot organ is removed from contaminated soil, thus the purpose that pollutant in soil Pb is removed in realization.The present invention utilizes the super enriching plant rough melic herb to administer the Pb contaminated soil, have cost, workable, do not destroy soil physico-chemical property, do not cause secondary pollution and preventing that contaminated soil wind erosion, water erosion from all having good advantages such as effect.
Summary of the invention
The method that the object of the present invention is to provide Pb in a kind of rehabilitating soil to pollute, this is a kind of not only economical and efficient but also the phytoremediation technology that can reach the Pb contaminated soil of better regulation effect.
For realizing above-mentioned purpose, the present invention adopts following technical scheme:
At heavy metal Pb Polluted area plantation rough melic herb, annual March in October to next year old strain has been dug, be divided into several Xiao Cong, every clump has seedling 5-6 root, and 20cm * 15cm opens nest by seeding row spacing, and every nest is planted 1 clump, and blinding compresses.Plant the back and receive 1 time the 1st year winter, annual later on June and October respectively gather in the crops 1 time, extract aerial part, carry out the smelting of Pb and extract.Annual so repeatedly later on offshoot breeding 1 time.
Remarkable advantage of the present invention is: (1) reduces the rehabilitation cost of Pb contaminated soil; (2) heavy-metal contaminated soil is carried out the original position reparation, leave soil alone, can not cause secondary pollution; (3) to preventing that contaminated soil wind erosion, water erosion from all having good effect.
Protecting method of the present invention can be used for mining area heavy metal-polluted plants reparation, soil ecology recovery etc.
The specific embodiment
Embodiment 1:
Annual March in October to next year, old strain has been dug, be divided into several Xiao Cong, every clump has seedling 5-6 root, and 20cm * 15cm opens nest by distance between rows and hills, and every nest is planted 1 clump, and blinding compresses.Plant the back and receive 1 time the 1st year winter, annual later on June and October respectively gather in the crops 1 time, extract aerial part, carry out the smelting of Pb and extract.Annual so repeatedly later on offshoot breeding 1 time.
Embodiment 2:
Annual March in October to next year, old strain has been dug, root is divided into several Xiao Cong after cutting off aerial part (reservation 2-3cm), every clump of 5-6 root, 20cm * 15cm opens nest by distance between rows and hills, and every nest is planted 1 clump, and blinding compresses.Growth was gathered in aerial part after 5-7 month, burned then and reclaimed Pb.
Embodiment 3
The absolute content of rough melic herb aerial part Pb reaches 1231.8 mgkg-1(greater than 1000 mgkg-1), the absolute content of Pb reaches 934.11 mgkg in the root-1, the Pb content of aerial part in the root, the transhipment coefficient is 1.32 (greater than 1), absorption coefficient is 0.313, and can restrain oneself the murder by poisoning of the P in soil b of higher concentration.It is thus clear that rough melic herb has stronger turn-over capacity to heavy metal Pb, can to greatest extent the Pb in the soil be taken away and transfer to aerial part, meet the essential characteristic of super enriching plant.
Annotate: the transhipment coefficient is meant the ratio of plant shoot concentration of element and its underground part respective element concentration, has reacted the ability that plant shifts to aerial part under ground portion heavy metal; Absorption coefficient (also claiming the biological concentration coefficient) is meant the ratio of respective element concentration in plant shoot concentration of element and the soil.
The above is merely preferred embodiment of the present invention, and all equalizations of doing according to claim of the present invention change and modify, and all should belong to covering scope of the present invention.