Study On Electric Repair Of Heavy Metal Copper In Gold Tailings And Surrounding Soil

The heavy metal pollution of soil in our country is serious, and the improper exploitation of mineral resources is one of the main sources of pollution. The open dumps of tailings were eroded by wind and rain, leading to the heavy metals and other pollutants diffused to the surrounding soil. Therefor, the levels of heavy metals in soil was overproof, and plants, animals and human health will be endangered in this area. Electrochemical remediation is a promising technology to remediate fine-grained soils contaminated by inorganic, organic, and mixed contaminants. In this paper, the gold mine tailings and surrounding sol collected from Dali Bai Autonomous prefecture, Yunnan Province, China were investigated by electrokinetic remediation. The effect of different anode electrode solution, permeable reactive barrierC PRB) materials, degree of compaction, voltage gradiants and remedial time on the removal rate of copper was studied. The morphological changes of copper in the electrokinetic remediation were also investigated. This study can provide a reference for related research.The best experimental parameters was selected, result display:1. Through the analysis of the physical and chemical properties of the tailings, the copper content was 1.78g/kg, conductive rate was 89.9μS·cm-1, saturated water content was 40.9%, pH value was 8.80-9.79, The percent of water soluble species, acid extractable fraction, Fe-Mn oxides species, organic matter species and residual species in total copper content were 0.7%,5.8%,40.9%,9.7%, and 42.9% respectively, and these contents in soil were 5%,29%,45%.7% and 14%.2. The experimental results of the mine tailings show that:when the permeable reactive material was coconut shell activated carbon, anode solution was 5% dilute sulfuric acid solution, voltage gradient was 1.5V/cm, remedial time was 6 days, the quality of mine tailing was 550g and wasn’t compaction, the removal rate of copper in the near anode area was the highest, up to 86.7%.3. The experimental results of the soils show that:when the permeable reactive material was activated carbon from coconut shell with 30% phosphoric acid, anode solution was 15mg/L humic acid, voltage gradient was 2V/cm, remedial time was 4 days, it’s overall removal rate of copper is the highest, up to 90%.4. The experimental results of electrokinetic remediation of tailings and its surrounding soils show that the electrokinetic remediation of the residual state copper had no effect.The removal efficiency of copper in the soil was significantly better than that in the tailings, it shows that the copper in soil is more easy to desorption and migration under the action of electric field.