| In recent decades,the ecological restoration of mine wasteland has been paid more and more attention by all countries in the world.Complex has become an interdisciplinary research hotspot.Lead and zinc resources in the mining process and the surrounding areas and the surrounding ecological environment caused different degrees of pollution and ecological damage,resulting in vegetation damage,soil erosion,water quality deterioration,air pollution,collapse,landslides and other environmental problems.In the lead-zinc tailings reservoir,the heavy metal content is high,the nutrient is poor and the air permeability is poor.Therefore,most of the tailings pits become bare land and the water erosion wind erosion is serious.Therefore,it is necessary to carry out ecological restoration of lead-zinc tailings reservoirs.It is necessary in the process of resource exploitation And the effect of ecological restoration of lead and zinc tailings can be evaluated for the comprehensive evaluation of lead and zinc tailings or the same type of tailings ecological restoration and practical activities.In this paper,the results of the ecological restoration of lead and zinc tailings in southern China are taken as the object of study.The construction and evaluation methods of tailings and mine ecological restoration evaluation indexes at home and abroad are analyzed.Through field investigation,collecting data,combining with sustainable development theory,The evaluation index includes three aspects: soil physical and chemical properties,plant community traits and heavy metal pollution.The weight of each index is determined by analytic hierarchy process(AHP).Finally,The results show that the evaluation results are based on the comprehensive evaluation method and the fuzzy analysis method.The main contents are as follows:(1)Analyzed the characteristics of lead-zinc tailings in China and the impact on the environment,summed up the summary of China's lead-zinc tailings ecological restoration technology and ecological restoration of comprehensive evaluation of the progress of research.(2)Taking the ecological restoration project of Dajiaoling lead-zinc tailings in Zixing City as an example,the soil environmental improvement and plant community growth in the past three years after a series of remedial measures were investigated and analyzed.The results showed that the soil physical and chemical properties were maintained at the middle level,and the soil nutrient status improved,but not obvious.The plant growth was relatively good and the species was relatively abundant.The vegetation coverage in 2014,2015 and 2016 were 75% %,82%,97%,although the heavy metal content of the casing layer increased,but within the clean range,only a certain amount of Cd content exceeded.Artificial wetland import of four kinds of heavy metal content in the water Pb,Zn,Cu,Cd is much lower than the standard value of surface water class III,that continue to use this system is feasible;the soil microbial community diversity analysis showed that the repair area and uncontaminated area of microbial diversity is not obvious difference,soil environmental quality is good.(3)Based on the general method of comprehensive evaluation in lead-zinc tailings after ecological restoration on soil physicochemical properties,from three aspects of plant community characteristics and heavy metal pollution by selecting 12 indexes including bulk density,pH,organic matter,nitrogen,phosphorus,potassium,abundance index,vegetation coverage rate,Pb pollution index,Zn pollution index,Cu pollution index,Cd pollution index,the weight of each index was determined by constructing the evaluation effect of lead-zinc tailings ecological restoration based on AHP model.(4)According to the comprehensive evaluation method,the final evaluation score of 2014,2015 and 2016 is 3.7101,4.1829 and 4.3733,and the fuzzy evaluation method is in general,good and good with a high degree of agreement.The index system and scoring standard have a certain guiding effect on the evaluation of the ecological restoration effect of lead-zinc tailings. |
PDF Full Text Request