Passive remediation of mine impacted water using selected treatment media containing-bioreactor

Abstract

This study was carried out to develop a passive treatment method to treat contaminated water with heavy metals caused by mining activities using organic, industrial, quarry and mining waste itself. In particular, this study aims to evaluate the performance of selected treatment media in treating Acid Mine Drainage (AMD) (i.e. Spent mushroom compost (SMC), limestone (LS), steel slag (SS) and ochre). A series of tests were conducted to determine the effectiveness of the treatment media in single and mixed substrates treatment. For single substrate, both SMC and SS showed promising overall heavy metal removal efficiency of 94.6% and 96.7%, respectively. As for mixed substrates, R3 (composed of 40% SS, 30% SMC, 20% LS and 10% ochre) gave the best performance in overall heavy metal removal. This treatment ratio (4:3:2:1) was then used in column experiment where continuous flow of synthetic AMD water was supplied. After 30 days, results showed that heavy metals (i.e. Fe, Mn, Pb, Zn, and Al) were reduced significantly with 91–100% removal efficiencies except for Mn (61.15% efficiency). Therefore, this study has proven that the media chosen in passive treatment of AMD are efficient in the removal of selected heavy metals and in increasing the pH of AMD, which can be applied for real on-site treatment of such cases.