| The land and the environment is very severe damage because mining. Therefore, when mine development and construction, protecting the ecological environment of mining areas, strengthen the land reclamation and ecological restoration is a strategic systems engineering.Reclaimed Coal Mine Subsiden-ce in the absence of soil resources, the search for sources of rich, high nutrient content of crops suitable for reclamation of media and become a research focus in land reclamation.Previous studies have used fly ash, respectively lees, sludge, furfural residue prepared substrate, instead of soil to fill for the reclamation of subsidence, but the matrix contains a certain amount of heavy metals, including cadmium content higher than the "soil environmental quality standards ", it is difficult widely used in agricultural production. Therefore, this test based on the current phytoremediation research focus, according to the physical and chemical properties of reclaimed Matrix, select the value of economic value or ornamental plants using cadmium accumulation experiment, plant growth characteristics, and its effect on cadmium-rich matrix of the repair capacity, and Cd-rich plants to study the use of the value of comprehensive evaluation of rehabilitation of social, economic and ecological benefits, to expedite the subsidence of land reclamation and land use provide the basis for restructuring.The results showed that:(1) Matrix of the physical and chemical properties to meet the needs of plant growth. Three kinds of substrates were lower than average bulk density of soil is conducive to plant growth and nutrient transformation; organic matter, available nitrogen, phosphorus and potassium content of plants through the absorption and decreased after the rain leaching, but in the actual production can be Fertilization methods to solve; three kinds of substrate pH values were between 6.5-7.1, the pH required to meet the plant growth environment; matrix high salt content of the initial configuration, after a year of plant cultivation and reduced precipitation leaching irrigation to 2.00g·kg-1-2.51g·kg-1, fully meeting the needs of normal growth of plants.(2) Early preparation, three matrix Zn, Ni, Hg, Pb, Cr,, As, Cu content of no more than two standard values of the soil environment, but the cadmium content than the standard value (0.3g·kg-1) 6-8 times. Use of phytoremediation, plants grow by 3-5 years of irrigation, leaching and precipitation, the cadmium content in the matrix decreased 0.3mg·kg-1 the following can be used for the production of arable land for cultivation of various crops.(3) Tthe same species growing in different soil conditions are different. Amaranth, kale, alfalfa, and castor grow best in substrate 1; zinnia, marigold and amaranth grow best in substrate 2; cypress grow best in the substrate 3.(4) In an annual removal and removal of plants on the matrix as an evaluation index Cd removal:the three matrix kale Removal of Cd are the best; followed by amaranth, and castor; again alfalfa and zinnia; Kochia, Marigold, amaranth in the removal of three matrix of relatively poor. In addition, biomass determines the size of the same species on different substrates removal of Cd.(5) Value of fixed plant that:alfalfa, castor, amaranth, cypress, kale Cd content in the feed to the appropriate health standards and food contaminants limited targets, safe feed, pharmaceutical or food; kale, Kochia, Marigold, amaranth, zinnia has a high ornamental value, can be used for gardening and landscaping to improve the ecological landscape reclamation area; In addition, castor, marigold can also be used for industrial production obtain higher economic returns.(6) Subsidence of land reclamation carried out by matrix, phytoremedia-tion technology to remove through the matrix exceeded the Cd, not only to avoid the waste of land resources and environmental pollution, and solve the difficult problem of plant repair, improve economic efficiency, social and ecological benefits. Suitable for large areas of wasteland reclamation and promote the use of, and to improve the ecological environment in mining areas to provide a new approach.
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