Acid mine drainage remains one of the most significant challenges in the mining industry, whether in gold or coal operations. It forms when rocks containing sulphide minerals react with rainwater and air, producing acidic water capable of dissolving metals. When this water flows into rivers or lakes, it can damage ecosystems and pose risks to living organisms.
Traditionally, mining companies have treated acid water by adding lime or other chemicals to neutralise its pH. While this method works quickly, it is costly and generates large volumes of sludge that require further handling. For this reason, researchers are increasingly exploring more natural and sustainable alternatives: bioremediation.
Bioremediation makes use of microorganisms that can convert sulphate into sulphide. The sulphide then reacts with dissolved metals to form harmless precipitates, resulting in cleaner water with a near-neutral pH. These microbes thrive by consuming simple organic materials such as straw or compost as their energy source.
In several countries, constructed wetlands have already been established to treat acid mine drainage using plants and bacteria. Such systems not only neutralise water but also create green habitats for birds and insects. Another approach involves simple organic reactors, through which acidic water is channelled across organic matter so that microbes can work more effectively.
At Agincourt Resources, bioremediation for acid mine drainage is currently at the pilot stage, with small-scale trials underway to test the effectiveness of local microbes under site-specific conditions. If successful, this technology could be implemented on a wider scale in future and stand as a source of national pride.
The advantages of bioremediation are clear: it is more environmentally friendly, more cost-effective over the long term, and avoids producing large amounts of toxic sludge. Indonesia’s tropical climate, which supports year-round microbial and plant growth, further enhances its potential for success.
Although bioremediation of acid mine drainage is not yet perfect and requires further research, it offers new hope: what was once considered hazardous waste can be transformed into safe water. This is proof that science and nature can work hand in hand to build a more responsible and sustainable future for mining
