Research On The Ecological Restoration Modes Of Mining-induced Subsidence Land In Huainan Tianji Coal-mining Area

Huainan is a typical coal-mining city, and an important energy industry base in east of China. Now, accompany with"coal-power"integrated construction, waste-water, waste gas, industrial solid waste and subsidence land, that"three wastes, one subsidence"has been formed, which are prominent eco-environment problems in ecological mining area construction. This research subject chooses prosperous mining area(Panxie new mining area, in the north of Huaihe river), take the first case of"coal-power integrated"project—massive industrial waste (fly ash) ecological treatment in Tianji power plant, land reclamation and ecological rehabilitation of coal-mining subsidence land in Panji No1 coal mine, research and discuss optimal"synthetic eco-restoration model", construct"science-technology demonstration garden of eco-environment restoration in Tianji coal-mining subsidence land".This paper carrys on comprehensive assessment of eco-environment restoration technology, which based on social economic evaluation and comprehensive analysis of eco-environmental survey data,our studying team developing eco-environment risk analysis of subsidence water and fly ash ecological treatment, by applying this research results, and combining the my conclusion of eco-agriculture application feasibility with fly ash,"Tianji synthetic eco-environment model"is established, that is dynamic filling with fly ash and multiform non-filling eco-restoration model of coal-mining subsidence land.I plan and design the eco-agricultural test of fly ash mixed with soil, research soil properties and crop growth character in different soil covering conditions, which based on filling reclamation with massive fly ash, then research bio-availability of metal in fly ash during growth process of plants. The results showed that, the best covering soil thickness was 30cm, bio-availability of metal and food security both come up to relative standards.This paper establishes "Tianji restoration model" based on eco-environment system restoration theory, and constructs "Tianji science-technology demonstration garden of eco-agriculture". For the dynamic filling with fly ash in coal-mining subsidence land, by optimal designing scheme of dynamic filling with fly ash, it is suitable for developing eco-agriculture, especially exploiting subsidence water field around the area, greatly developing high additional value livestock and poultry cultivation industry, as well as elevated stereo-agriculture. For non-filling subsidence land, it is feasible to implement multiform engineering of land reclamation and ecological rehabilitation(just as dredging and draining method, dig deep and pad shallow project, land levelling project), construct"agriculture, forestry, grazing, fishing, poultry" eco-agriculture landscape and "material flow, energy flow" circular ecosystem.In conclusion, on the basis of research and discussion, two restoration models are put forward, which are the basis of construction of"ecological mining area"in Huainan, and the referential beneficial solution for coal-mining subsidence lands to realize the sustainable development is supplied, all of this work has great significance to comprehensively promote eco-environment restoration of subsidence lands, and the construction of"Ecological Huainan".