Investigation of Cyanide and Heavy Metals Contamination of Groundwater, Soil and Waste of Gold Industries: A Case Study of Takab Kanikaran

Gold Mining companies are one of the industries that if not properly act in accordance with the sustainable development goals, they will cause a lot of environmental contamination in the environment. In these factories, tailings dams are places where effluents and tailings materials from gold mining factories are collected and stored, and if not properly controlled and monitored, they can be a significant source of cyanide and heavy metals contamination. In this study, cyanide and heavy metals contamination of groundwater, soil and tailings of Takab gold mine were studied.

In this descriptive cross-sectional study, 19 stations were selected for sampling of piezometric wells, soils around the mine, and tailings dam of the Takab gold mine during a one-year period. Water samples were transferred to the laboratory after stored at 4 °C. The Heavy metals in water samples, soil, and tailings were measured by Atomic Absorption Spectrophotometry (AAS) method.

The amount of cyanide, mercury and arsenic were measured in the range of 0-105, 0-83.7 µg L-1 and 0-120.4 mg L-1 in water samples, respectively. Also the amount of these contaminants (cyanide, mercury and arsenic) in soil samples were in the range of 37.02 - 58 mg kg-1, 0 - 25.6, and 27.6 - 420 µg kg-1, respectively.

The results showed that, there was no significant difference in the mean concentration of arsenic in the water samples of the studied wells. But in the case of mercury and cyanide, the studied wells have a significant difference. Tailings samples had the highest concentration of cyanide and heavy metals, and had significant differences with soil and water samples.