Phytoremediation of Arsenic and Manganese from Tailing Storage Facility at Gold Mining

Abstract

The phytoremediation and removal efficiency of dicotyledon cultivated in Arsenic (As) and Manganese (Mn) contaminated area were focused in this study. Three kinds of dicotyledon, Acacia mangium, Leucaena leucocephala and Acacia auriculiformis, were selected and used as remediated species. All plants were cultivated in the Tailing Storage Facility area (TSF) at the Gold Mine for 6 months. Their toxicity symptoms, uptake and accumulations of As and Mn in root, stem and leaves were also observed. In addition, contaminated soil was analyzed for background As and Mn. The result showed that TSF soil have been contaminated with As and Mn at 51.03+0.74 and 1,670+0.18 mg/kg of dried soil, respectively. At the 6^th month of cultivation, both soil and plant samples were collected then analyzed for As and Mn accumulation. Results showed that As and Mn had been accumulated in the whole parts of A. mangium at7.03±0.80 and 166.00±22.16 mg/kg, respectively. A. auriculiformis accumulations were 6.56±1.14 and 172.75±29.37 mg/kg for As and Mn, respectively. Meanwhile, L. leucocephala was the lowest accumulated specie (As =0.60±0.08 and Mn =16.10±2.29 mg/kg). Moreover, the highest accumulation of As and Mn were found in both leaves and stem rather than in root. For As accumulation in dicotyledon species, A. mangium had become the highest As accumulated specie followed by A. auriculiformis and L. leucocephala, respectively. For Mn accumulation, A. auriculiformis was the highest Mn accumulated specie followed by L. leucocephala and A. mangium, respectively. As considered growth rate of dicotyledon, biomass of A. mangium dried was greater than A. auriculiformis and L. leucocephala (1,365.24, 1,267.88 and 122.16 g/plant, respectively) and toxic sign showed at 4.81, 5.27 and 34.25% respectively. Overall, it was obvious that both, A. mangium and A. auriculiformis had showed their tolerance on As and Mn accumulation and also suitable to be used for TSF site remediation.