Investigation of sulfidic natural water in Sebau Lombok Island to remove dissolved copper (Cu~(2+)) in acid mine drainage

摘要

The aim of this research is to investigate the potential of Sulfidic Natural Water (SNW) of Sebau-Lombok Island as a substitute for the expensive and toxic sulfidising agent, Natrium Hydrosulphide (NaHS), in removing the dissolved Cu~(2+) from the Acid Mine Drainage (AMD). The study was conducted by characterising SNW from several sampling points, comparing the recovery of the dissolved Cu~(2+) using NaHS and SNW at the same pH level, and studying the potential of SNW in several concentrations to precipitate dissolved Cu~(2+) from the AMD collected from Copper Mine Industry of Batu Hijau Sumbawa Island. The SNW of Sebau exhibited several characteristics, such as: warm temperature (37-39°C), slight alkaline condition (pH = 7.20 - 7.25), electrical conductivity (2330 - 2370 μmhos/cm), sulphate content (4.08 - 6.38 mg/L), and sulphide content (13.58-16.79 mg/L). NaHS (11 × 10~(-4) M) could precipitate the dissolved Cu~(2+) (44.45 mg/L) up to 71.3%, while pure SNW of Sebau could completely precipitate the dissolved Cu~(2+) (44.45 mg/L) at pH 5.5. Applying the SNW of Sebau more than 20% could also precipitate the dissolved Cu~(2+) in AMD (141.35 mg/L) for more than 93%. These results demonstrated that SNW of Sebau has a potential to remove the dissolved Cu~(2+) and replace the function of NaHS as a sulfidising agent in the AMD treatment.