Recovery of Metals from Acid Mine Drainage Using Organic Polymer
Bessho, Masahiko (1); Markovic, Radmila (2); Apostolovski Trujic, Tatjana (2); Masuda, Nobuyuki (1); Bozic, Dragana (2); Stevanovic, Zoran (2)
1: Akita University, Japan; 2: Mining and Metallurgy Institute Bor, Serbia
Acid mine drainage (AMD) is a serious environmental pollution issue in the mining industry. It has an extremely acidic pH value, and contains heavy metal ions. Thus the effluents, released into rivers around mines, pose an immediate threat to the ecological balance. AMD includes not only a large amount of metals such as iron, copper and zinc but a low amount of various ionic metals. To use these metals as resources, separation of metals is required as well as recovery of them from AMD.
Adsorption method is one of the effective techniques for recovery of metal ions from water. Recovery and separation of the metals by adsorption can satisfy both of the purification of AMD and the efficient use of recovered metals. This study aims to development of a novel adsorbent using natural organic polymer. And then, the possibility of application of natural organic polymer for recovery of metal ions from simulated wastewater was investigated. is desirable that a step to purify AMD leads to recycling of major or minor metal elements.
In this study, chitosan, one of the polysaccharides, was used as an adsorbent. And then, copper-recovery test was mainly carried out. Chitosan could recover more copper ions at over pH 3. In case of 2 mM (approx. 130 mg/L) of Cu solution, 0.1 g of chitosan adsorped over 90 % of Cu from 50 mL of the Cu solutions. Finally, the Cu concentration in the solution after addition of chitosan decreased to less than 10 mg/L.
In Bor area, Republic of Serbia, AMD is flowing out to natural rivers without any treatment, so the river water is highly contaminated and impossible to use it for anything. Generally, the neutralization method has been applied to AMD for pH adjustment and removal of metal ions as hydroxides. This approach using natural organic polymers will also be able to apply lower content of dissolved metals. Combination of both neutralizing method and this method will lead to more efficient treatment of AMD and recovery of metals.