The Research On Engineering Design And Effect Of Ecological Restoration For Lead-zinc Mine Wasteland

Lead-zinc mine mining made great contribution to the high-speed development of national economy also caused serious environmental pollution for a large amount of Lead-zinc mine wasteland. How to control pollution diffusion and restore the vegetation became a focus in the study of Lead-zinc mine wasteland ecological rehabilitation. The present study taked lead-zinc mine wasteland in Zixin county as the research object, used "system of plant community, intercept zone, artificial wetland system" mode of ecological restoration technology for engineering design,and analyzed its operation effect,aiming to provide technological support for the protection of the environmental protection and the xiangjiang river heavy metal pollution prevention and control, and provide technology demonstration for the ecological restoration of the same type.(1)The municipality engineering design:according to the site conditions, lead-zinc mine wasteland area were divided into "ecological restoration area (15480 m2)-ecological intercept zone (2560 m2)-artificial wetland system (150 m2)" to carry on the design. Ecological restoration area:Natural vegetation recovery combined with artificial cultivation of excellent native tree species(Koelreuteria paniculata, Robinia pseudoacacia,Pinus massoniana,Broussonetia papyrifera.Cinnamomum camphora, Osmanthus fragrans,Swida wilsoniana), applying special organic bacterial manure plant hole to promote plant growth, improve the effect of the heavy metal resistance and repair; Ecological intercept belt:"Eco-economy" plant(Elaeocarpus glabripetalus, Osmanthus fragrans,Michelia chapensis,Zelkova serrata,Taxus chinnsis,Melia azedarach,Schima superba,Cunninghamia lanceolata,Cinnamomum camphora,Photinia xfraseri,Ligustrum quihoui,Osmanthus fragrans,Cynodon dactylon) combined with configuration of Joe, irrigation and grass to form a stable effect of pollution control system of biological communities, tackle pollution area of soil and water loss, and strengthen the function of repair and the seasonal landscape effect, intercepting ditch and soil retaining in peripheral cut-off was established to control the spread of the pollution; Artificial wetland system: adopting the undercurrent of artificial wetland, through a combination of substrate and plant configuration(Hibiscus syriacus,Ligustrum lucidum,Ophiopogon japonicus), ecological treatment of Leach and soil surface runoff after discharging standard for the surface water environment quality standard (GB3838-2002) class Ⅲ water quality standards.(2)Project running effect:in July, October and November,the content of Pb、Zn、Cu、 Cd in out-water of the artificial wetland achieved the surface water environment quality standard (GB3838-2002) class Ⅲ water quality standard, achieved the design goals and the system were running well; in the early part of the ecological restoration, there are 36 species of the natural growth of plant, mainly gramineae and compositae, and most plants were enriched in certain heavy metals; After a year of ecological restoration, the migration of heavy metals showed a tend of upward and downward from tailing layer, and Natural plant species to 16, present a type to the shallow root plant succession law; Plants grow well planted and landscape effect is good.