Abandoned Acid Mine Drainage Lab Report

Abandoned Acid Mine Drainage at Shoup’s Run
Introduction
Acid mine drainage (AMD) is an industrial waste which is the result of the extraction process of the mineral coal from the ground. It causes widespread pollution in the streams above and below the coals fields. AMD is caused when water flows through sulfur-bearing materials forming acidic solutions. It is formed when pyrite (FeS2), an iron sulfide, is exposed and then reacts with air (O2) and water (H2O) to form sulfuric acid.
2FeS2 (s) + 7O2 (g) + 2H2O (l)  2Fe2+ (aq) + 4SO4-2 (aq) + 4H+ (aq)
Ferrous Iron also reacts with air causing the creation of Ferric Iron which then reacts with water forming Ferric Hydroxide and more acidity.
4Fe2+ (aq) + O2 (g) + 4H+ (aq)  4Fe3+ (aq)
Both treatment styles work to neutralize the acids and remove the heavy metals.
Method
On November 13, 2013 we travelled to Saxton, PA where we observed Shoup’s Run along with Miller’s Run stream which have been noted for having poor pH due to AMD (Figure
1). Miller’s Run had a passive treatment system working so it is on better shape than Shoup’s
Run. The passive treatment for the water in Miller’s run is working to drop the acid and heavy metal levels (Figure 2). First, it neutralizes the pH and alkalinity, which is the ability to buffer changes in pH and withstand the changes. When the water flows over the limestone and reacts with it, the rock is dissolved by the acid in the water and neutralizes it. The next part of the passive treatment is draining the water into settling ponds. The metals settle onto the bottom of the pond and do not continue down the stream because the flow of the water is slowed down.
The metals settle and turn the rocks a rusted red from the iron and a blue from the aluminum.

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Figure 1: Map of streams of where water was observed and tested.

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Figure 2: Diagram of Shoup’s Run passive water treatment plan

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Field
The inlet had a pH of 3.2 with 0 ppm for alkalinity. There was also a high count of heavy metals given to us. These numbers mean that the conditions of the stream are unlivable for all organisms. The high levels of iron in the water form what is known at armoring which is when a layer of red rust forms on the rocks. The layer of armoring prevents the rocks from doing their job of neutralizing the water. In order to prevent this from happening, bulldozers must be brought in to turn over the rocks periodically to keep the armoring process at bay. The limestone bed was however fulfilling its purpose of lowering the acidity levels in the water and neutralizing it. The water tested at the outlet which was also the inlet for the wetland showed that the pH was
6.7.
The wetland had an inlet pH of 6.7 after running through the limestone of the system above it. The pH allowed the heavy metals to settle on the bottom on the pond which was visible from the water’s edge as white slurry on the bottom. With an alkalinity of 89 ppm, it is obvious that even after these two parts of treatment that the water is in much better condition and can