Carbide lime in acid mine drainage treatment

The objective of this study is to find a suitable quantity of carbide lime in acid mine drainage (AMD) treatment. Carbide lime, which is a waste of acetylene gas process was used as neutralisation material in AMD treatment. This study used carbide lime, because it has high calcium content that can increase pH value of AMD. Carbide lime also has the capability to reduce certain heavy metals in water sample such as cadmium, lead, zinc etc. Water sample used in this study was collected from a tailing pond of an active tin mine and its pH was around 2.6-2.8. Jar test was used in the laboratory to investigate the capability of carbide lime in treating acid mine drainage. The optimum quantity of carbide lime obtained in treating AMD is 1.5 g which can increase pH value and reduces certain heavy metals that comply with Standard A and B of Environmental Act 1974. Other quantities such as 2.0 g and 2.5 g carbide lime were capable to reduce heavy metals and semi heavy metal but pH values obtained were higher compared to both standards of Environmental Act 1974. Generally, the experiment results show that carbide lime is suitable to be used to treat AMD.