A "Win-Win" Situation for Acid Mine Drainage
Acid Mine Drainage is one of the greatest environmental hazards that is associated with mining processes and degrades more than 4,500 stream miles in the mid-Atlantic region of the US alone. When water flows through abandoned and active coal mines, a reaction occurs between the water and the rocks containing sulfur bearing minerals. This reaction has the ability to contaminate drinking water, disrupt aquatic plants and animal reproduction, and corrode parts of infrastructure due to the net acidity of the drainage.
However, according to a new study by the US Geological Survey at Leetown Science Center, a byproduct resulting from the treatment of acid mine drainage may actually have a second life in helping clean waters coming from agricultural and wastewater discharges.
The report, published in the Journal Water, Air, and Soil Pollution, shows that dried acid mine drainage sludge that result from treating acid mine drainage discharges can be used as a low-cost adsorbent elsewhere to efficiently remove phosphorus from agricultural and municipal wastewaters. The phosphorus that has been adsorbed by the mine drainage residuals can later be stripped from the residuals and recycled into fertilizer. The mine drainage residuals can be regenerated and reused for a number of additional treatment cycles.
"This wonderful result shows the inventive application of some very sophisticated environmental chemistry to create a new life cycle for what otherwise would have been some problematic waste products," said USGS Director Marcia McNutt. "It sets the bar high for future studies in environmental remediation."
Acid mine drainage is produced whenever sulfide minerals associated with coal and metal deposits are exposed to air and moisture. The resulting acid and dissolved metals are toxic to most forms of aquatic life, and untreated acid mine drainage has impacted more than 5000 miles of streams in the Appalachian region, with associated economic impacts of millions of lost dollars in the tourism and sport fishing industries.
Application of this new technology has the potential to decrease acid mine drainage treatment costs, prevent degradation of aquatic ecosystems, and recycle valuable nutrients.
Philip Sibrell, lead author of the study says: "This new technology could reduce or eliminate the need to dispose of acid mine drainage sludge, instead making that same sludge useful in addressing the urgent need to reduce the amount of phosphorus going into aquatic ecosystems; it's a win-win situation."
Read more at the USGS Newsroom.
See the complete report at Springer Link.
Acid Mine Drainage image via Shutterstock.