Study On Transfer Characteristics Of Heavy Metals From Minetailing To Soil-Plant

With the development and utilization of gold mine area，The production of mine tailingis becoming more and more big. It not only occupies the land resources, but will cause harmto surrounding environment. When raining, the heavy metals of mine tailing will bedissolving out, and then infiltrate into the soil. The soil will be polluted by heavy metals.Plants that grow in this kind of pollution soil will enrich heavy metals of the soil. Throughthe food chain, it will harm to human health.In this article, through field sampling monitoring, indoor simulation and potexperiment to explore the Heavy metals of mine tailingrelease rule and Migration patternsin soil and plants, which find the science method to solve the problem that the tailings wasteresidue polluted environment and provides the theoretical foundation and governance to theHeavy metal pollution of the environment evaluation.So the study of migration patternsthat the heavy metals of tailings waste residue in soil-plant has important theoreticalsignificance and practical value.(1) According to the outdoor reconnaissance, we collected30soil samples around theTailing slag accumulation point. Use Nemerow Pollution Index, geological cumulativeindex and the potential ecological harm index to evaluate the soil samples. The results showthat: Hg, Cd, Pb, Cu pollution in the soil around the Tailing slag is serious, Cr, As, Znpollution is lighter or even no pollution.(2) Leaching mine tailingin the laboratory to simulated mine tailingunder naturalrainfall, the Heavy metal concentration in the solution is changing with the change of time.The results show that: At the beginning of the leaching, Cr, Cu, Zn, Cd, Pb concentration ofleaching solution is increasing.10days, heavy metals concentrations of leaching reachsolution maximum, after10days, heavy metal concentration in the solution began toreduce.(3) Leaching solution infiltrate the soil in indoor and outdoor to simulate migrationbehavior that the heavy metals of tailings leaching solution in soil vertical. The results showthat: after infiltration, Cu, Zn, Cd elements are mainly distributed in the soil surface, Pb andCr are not enrichment in soil surface. To analyze the form of Heavy metals in the in situ soil, we get that Acid extractable form of Cu、Zn、Cd increase bigger than Cr and Pb. The linearrelationship between the total content and effective form of Cu, Zn, and Cd is very obvious,Linear fitting degree is higher. Fitting equations: Cu：Y=0.4059X-14.615,R2=0.9946；Zn：Y=0.5662X-41.723，R2=0.9949；Cd：Y=0.5723X-0.0725，R2=0.9954.The total content andeffective form of Cu, Zn, and Cd has no linear relationship.(4) Pot experiments in the laboratory. Use three different concentration leachingsolution and water to dispose the soil, then planting green vegetables and cabbage in thesefour soil samples. The results show that: Heavy metals have inhibitory effect on the growthof plants.Enrichment coefficient of heavy metal in vegetables and cabbage isCd>Zn>Cu>Cr>Pb;Under the condition of compound pollution of heavy metals,Enrichmentability of green vegetables is bigger than cabbage, especially to Cu、Zn、Cd;The relationshipbetween Enrichment factor of heavy metals in plants and acid extractable of heavy metals insoils is positive correlation. Food safety evaluation results: vegetable which grows in thesoil around tailing slag is not safe for people.