Anonymous region where:: Paper type: Expert Authors On the ecological and environmental effects of mining and its ecological restoration of downloads: 73 Abstract: [keyword Papers] ecological effects of mining ecological restoration [Abstract] exploitation of mineral resources has become China's National An important means of economic growth, but mining has triggered a series of ecological and environmental problems, leading to ecological degradation and environmental pollution in the mining area, which seriously restricts the sustainable development of the social and economic development of the mining area. This paper systematically analyzed the ecological effects of mining, and based on the successful experience of ecological typical mining recovery, summed up the typical technology for China's mining ecological restoration, the main soil remediation heavy metal pollution from mining waste land, restore vegetation mine, The comprehensive management of soil erosion is discussed in three aspects.

Due to the immobility of mineral deposits, mining has long occupied, destroyed and polluted land, changed the structure of regional water system, destroyed flora and fauna, triggered a series of social economic and ecological problems, and became the focus of global environment and development. one. The land reclamation work in China's mining areas started late and the land reclamation rate is low. It is urgent to explore land reclamation technology suitable for China's national conditions and improve land reclamation rate and production potential. Based on the systematic analysis of the ecological and environmental effects of mining, this paper will summarize the typical technologies suitable for land reclamation in China's mining areas, with a view to promoting the further development of land reclamation work in the country.

First, the ecological environment effect of mining

(1) Inducing geological disasters. Due to underground goaf, the excavation of the ground and slope affects the stability of the mountain and slope, which often leads to frequent ground collapse, cracking, collapse and landslide. The waste slag discharged from the mine is piled up on hillsides or valleys. The waste rock is mixed with the soil to reduce the friction of the waste rock, and the water permeability becomes small and waterlogging occurs. It is also easy to induce mudslide under heavy rain.

(2) Changes in hydrogeological conditions and water pollution. The collapse, cracks and mine drainage of the mining area will change the water storage structure of the mining area, causing the groundwater level to drop, the wells to dry up, forming a large-area dredging funnel; the change of surface runoff will cause the water source to be depleted and the water conservancy facilities to be lost. The original function directly affects the cultivation of crops. At the same time, the mine pit water and waste rock leaching water generated during the mining process generally fail to meet the industrial wastewater discharge standards, seriously affecting the survival and reproduction of aquatic organisms and drinking and drinking.

(3) Soil degradation and pollution Because the topsoil is removed after mining, usually new soil or slag, coupled with the heavy pressure of large mining equipment, often makes the soil hard, compact, organic matter, nutrient and water shortage. The ground collapse causes the groundwater level to drop and soil fissures to occur. Nutrients in the soil also flow into the goaf or depression along with fissures and surface runoff, resulting in shortage of soil nutrients in many places and a decrease in soil carrying capacity. Mine solid waste (coal gangue and the like) by rain erosion, leaching, in which highly toxic and harmful components into the soil, resulting in contaminated soil pH (mainly strongly acidic pollution), the organic toxic pollution and heavy metal pollution. The soil has limited pollution and self-purification ability. When the pollutant exceeds its critical value, it will export pollutants to the external environment, and its own composition and function will also change, eventually leading to the depletion of soil resources. Moreover, soil pollution will migrate under surface runoff and biogeochemistry, jeopardizing the environmental quality of adjacent areas, and contaminated agricultural products will endanger human health through the food chain.

(4) Soil erosion is intensified. Mining directly destroys surface vegetation, open pits and wells and mines pump out groundwater, causing the groundwater level in the mining area to drop drastically, resulting in poor soil and degraded vegetation, which eventually leads to the formation of large areas of artificial bare land in the mining area, which is easily washed away by rain; The field and tailings occupy the land, forming the undulations of the ground and the distribution of the grooves, increasing the flow rate of the surface water, making the water and soil more mobile and scouring.

(5) Loss of biodiversity. Vegetation removal, soil degradation and pollution, soil erosion, and the maintenance of biodiversity in the mining area are fatal blows, seriously threatening the survival of animals and plants.

Second, the typical technology of ecological restoration in mining areas

(1) Treatment of soil pollution in mining areas

1. Treatment of heavy metal pollution in mining areas. Heavy metal pollution control in mining areas at home and abroad mainly includes three types of physical, chemical and biological treatment technologies. Among them, bioremediation technologies include microbial remediation technology, animal remediation technology and phytoremediation technology. The facilities are simple, the investment is small, and the environmental disturbance is also small, which is considered to be the most vital.

2. Improvement technology for soil fertility in mining areas. Soil fertility improvement technology is the improvement of soil granule structure, pH and other physical and chemical properties and the improvement of soil nutrients, organic matter and other nutrient conditions. This is one of the ultimate goals of ecological restoration in mining areas, including: (1) topsoil conversion: Before the mining, the surface layer and sub-surface soil are removed and stored. After the project is finished, the soil is returned to the original place. This destroys the vegetation, but the physical properties, nutrient conditions and seed bank of the soil remain basically the same, and the native plants can quickly settle down. (2) Guest soil cover: When the abandoned soil layer is thin, it can be covered with mature soil, directly fix the surface soil layer, and improve the physical and chemical properties of the soil, especially the introduction of nitrogen, microorganisms and plant seeds. Vegetation provides favorable conditions. (3) Improvement of soil physical properties: The goal of improving soil physical properties is to increase soil porosity, reduce soil bulk density, and improve soil structure. Short-term use of plowing and application of farmyard manure can be used. (4) Soil pH improvement: For acid soils with low pH values, bicarbonate or lime may be applied to adjust acidity, increase calcium content in soil, and improve soil structure. (5) Improvement of soil nutrient status: mainly including chemical fertilizers, organic waste, nitrogen-fixing plants, green manure, and microorganisms.

(2) Restoration of vegetation in the mining area. According to the climate and soil conditions of the mining area, the vegetation screening should focus on the recent performance of the vegetation variety, taking into account its long-term advantages. The choice of plant varieties must first consider the principle of suitable tree based on biological characteristics, especially the selection of roots developed and solidified. A native plant with good slope-fixing effect, high survival rate and fast-growing. When arranging plants, the slope structure, post-planting management requirements, and natural conditions should be considered to determine the form and variety of the plant. At the same time, it should be considered in accordance with the design purpose: to adapt to the conditions of nearby vegetation and scenery.

(III) Comprehensive treatment of soil erosion

1. Solid waste interception project. In the dumping site, the slag wall, the slag dam and the drainage project shall be constructed to carry out the blocking and leakage prevention treatment.

2. Slope drainage project. For slopes affecting mine safety, sections such as intercepting ditches and flood drainage channels shall be arranged according to the length of the slope, and protected with forest and grass belts to increase vegetation coverage and reduce surface erosion of surface runoff to ensure safe operation of mining production.

3. Slope protection engineering. All kinds of slopes formed by mining, in addition to taking measures to restore vegetation as much as possible, according to the degree of slope stability and the impact on the surrounding, take appropriate engineering measures to protect. Slope protection uses stone slope protection or vegetation slope protection depending on the slope.

4. Land remediation project. For the large amount of waste rock piles, abandoned industrial sites and tailings ponds produced in the mine production process, the combination of storage and storage, drainage and slag disposal, effectively solve the "three wastes" pollution. At the same time, reclamation measures will be taken for the waste slag yard and tailings pond that have expired during the service period to improve land utilization.

5. Vegetation restoration project. Different measures were taken for all types of exposed surfaces to accelerate vegetation restoration.

Third, the conclusion

Mining has greatly changed the native landscape ecosystem, leading to ecological degradation and environmental pollution in the mining area. For the characteristics of the ecological environment of the mining area. The typical technical system of ecological restoration in mining areas in China mainly includes the treatment of soil pollution in the mining area and the improvement of soil environmental quality, the restoration of vegetation in the mining area, and the comprehensive treatment of soil erosion. It must be emphasized that the ecological restoration of the mining area is not only a technical engineering problem, but also inseparable from the socio-economic development of the mining area. It is a systematic project that integrates society, economy, resources and environment. Therefore, the land reclamation in the mining area is based on human development, comprehensively rectifying the natural, economic and social attributes of the land, and rebuilding the ecological balance while eliminating environmental hazards.

references:

[1] Xia Xinghui, Chen Jingsheng. Research progress in soil heavy metal pollution control methods. Environmental Science, 1997, 18 (3): 72-76.

[2] Peng Jian, Jiang Yijun, Wu Jiansheng, Liu Song. The ecological environment effect of mine exploitation in China and the typical technology of land reclamation. Advances in Geography, 2005, 24(2): 38-42.

[3] Kang Haicheng, characteristics and prevention measures of mine soil erosion in Baoji City. China Soil and Water Conservation, 2003, 7:32-34.

[4] Yu Jing, Yang Fuhai, Li Fuping. Summary of land reclamation in metallurgical mines. Journal of Hebei Institute of Technology, 1999, 21 (supplement): 41 ~ 47.

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