Acid mine drainage Mateo Transueo

What causes it……... ► Acid mine drainage (AMD) is the drainage produced from mines containing sulfide minerals which oxidize, causing the production of acid waters. Sulfide mines and coal mines are often sources for acid mine drainage. AMD is characterized by low pH (1-4), high dissolved iron, high dissolved sulfate, and high total hardness (Ca + Mg), and high trace metals. ► This blanket ( the color orange in the picture above ) is caused when the iron hydroxide precipitates out of the water due to a lower pH from acid mine drainage ► Simply water gets into mines and mixes with the metals causing it to become acid and doing what is stated above in big boy/ girl words.

Describes Effects ► Acid mine drainage is hazardous to the environment and it disrupts the nature cycle. ► This affects streams covering the stream bed with a thick red blanket blocking sunlight. ► When the plants die, the rest of the aquatic cycle is upset and ultimately the stream becomes barren which means life will cease to live. ► Several cases have occurred all over Canada where the metal from mines has combined with the acid from pyrite, resulting in the destruction of stream habitats. BYE BYE FISHIES

Problem in PA ► Drainage from thousands of abandoned coal mines has contaminated more than 3,000 miles of streams and associated ground waters in Pennsylvania and is the most extensive water-pollution problem affecting the four major river basins in Pennsylvania. Because coal-mine drainage can contain toxic concentrations of acidity, metals, and sediment, many of the mining impacted streams contain "no fish". Consequently, Pennsylvania loses approximately $67 million annually that could be generated if sport fishing were restored in the affected streams. The estimated cost for restoring the damaged watersheds is $5 billion to $15 billion.

Who What Effected ► Aquatic life and the life cycle would be effected by the stream being contaminated by the acidic chemicals. ► This causes the fish population to drop drastically because they cant survive in the harsh environment created. ► With the fish population decreased the wild life that depends on the fish to live will slowly decrease as well and die..

Possible Remedies ► There are a few remedies all do the same things basically what they do is they take another chemical that is a base and it counteracts the acidic chemicals that come from the mine. ► Carbonate neutralization ► Generally, limestone or other calcareous strata that could neutralize acid are lacking or deficient at sites that produce acidic rock drainage. Limestone chips may be introduced into sites to create a neutralizing effect. Where limestone has been used, such as at Cwm Rheidol in mid Wales, the positive impact has been much less than anticipated because of the creation of an insoluble calcium sulfate layer on the limestone chips, binding the material and preventing further neutralization. limestonecalcareousstrataCwm RheidolWales calcium sulfatelimestonecalcareousstrataCwm RheidolWales calcium sulfate

Possible Remedies cont.. ► Lime neutralization ► By far, the most commonly used commercial process for treating acid mine drainage is lime precipitation in a high-density sludge process. In this application, a slurry of lime is dispersed into a tank containing acid mine drainage and recycled sludge to increase water pH about ~9. At this pH, most toxic metals become insoluble and precipitate, aided by the presence of recycled sludge. Optionally, air may be introduced in this tank to oxidize iron and manganese and assist in their precipitation. The resulting slurry is directed to a sludge-settling vessel, such as a clarifier. In that vessel, clean water will overflow for release, whereas settled metal precipitates (sludge) will be recycled to the acid mine drainage treatment tank, with a sludge-wasting side stream. A number of variations of this process exist, as dictated by the chemistry of ARD, its volume, and other factors. Generally, HDS-generated sludge also contains gypsum and unreacted lime, which enhance both its settleability and resistance to re-acidification and metal mobilization. limeclarifierlimeclarifier

Video ► R7N3lSKg R7N3lSKg R7N3lSKg ► -WPA. -WPA -WPA

Worked cited ► nage nage nage ► ► mtrt.htm mtrt.htm mtrt.htm