A technology being developed by a Temple University researcher as a solution to Pennsylvania's historic problem with acid mine drainage also could have applications for the state's newest environmental challenge – hydraulic fracturing of Marcellus Shale.
behind in abandoned mines after coal is extracted contains sulfur impurities
that decompose and form sulfuric acid when exposed to air, water and microbes.
When water fills a mine’s underground tunnels, sulfuric acid can leach off the
walls and get into nearby ground water, according to Temple University
Chemistry Professor Daniel Strongin.
chemicals such as lime often are used to neutralize acidic runoff, they do not
eliminate the root cause, says Strongin. So his lab is developing a technology
that uses a specific class of lipid molecules that bind to the metal sulfide,
forming a hydrophobic layer that keeps water, oxygen and bacteria from causing
it to decompose.
who has been working on developing this lipid-based technology for the past
eight years, says that approximately 2,400 miles of waterways in Pennsylvania are
affected by the contaminated water from the abandoned mines, which typically is
acidic, and contains large amounts of heavy metals that are deadly to aquatic
roughly $19 million a year to address this issue, largely due to the vast
number of abandoned mining areas,” he says. “I’ve read that it’s estimated that
it would cost $50 billion to fix the entire problem.”
now believes that mitigating acid drainage using lipid technology could enable
the mine waters to be used in the process of extracting natural gas from the
Marcellus Shale formation. During hydraulic fracking, highly pressurized water
is pumped into the earth to break or fracture the shale and extract the gas.
process requires a tremendous amount of water; essentially, in a given well you
need 2 to 5 million gallons to fracture the rock and release the natural gas,”
he says. “As you might expect, people don't want to waste fresh water on that
that a panel commissioned by the governor of Pennsylvania recently has recommended using
water from abandoned mining areas for hydro-fracking the Marcellus Shale.
“It is my
belief that our lipid technology could be used to stop acid mine drainage, or
the root cause of acid mine drainage, in such a way that the waters emanating
from these abandoned mining areas would be more usable in the hydro-fracking
process,” he says.
that there is a cost incentive to remediate abandoned mining areas – which often
are in close proximity to the drilling areas – and the contaminated water
emanating from those mines for use in the natural gas drilling.
down on the costs to transport water to the wells, and you’re not using fresh
water resources for the drilling.”
to cleaning the acid mine drainage for use in drilling, Strongin also believes
the lipid technology may be useful for cleaning the flow-back water that is a
result of the hydro-fracking.
“A lot of
the same chemistry that these lipids carry out on the acid mine drainage may be
applicable to these contaminated flow-back waters, which carry a lot of
dissolved solids and particulate matter,” he reveals.
funded by the U.S. Department of Energy, Strongin’s research currently is being
supported by the Nanotechnology Institute.