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Tech researchers create first-of-its-kind study on microplastics in Tennessee waters
Caroline Hitchcock, Tennessee Tech graduate student, places a sample filter onto the
FT-IR microscope provided by Tech's Water Center.
Microplastics – tiny pieces of plastic less than five millimeters in size – can cause
big problems when they find their way into the ecosystem. Most research being done
now has focused on these tiny pollutants in oceans and estuaries, however researchers
at Tennessee Tech University have turned their attention to the freshwater of Tennessee.
Environmental engineering graduate student Caroline Hitchcock, with assistance from
Tania Datta, Ph.D., associate professor of civil and environmental engineering, and
Justin Murdock, Ph.D., professor of biology, have started investigating microplastics,
specifically their presence in wastewater treatment plants across Tennessee. As the
state boasts more native fish species than any other in the U.S., and the second-highest
species diversity of freshwater mussels, knowing how pollutants might be entering
the waterway is vital knowledge. The study is one of the first of its kind in this
state.
“Even to this day, when you look up Tennessee wastewater microplastics, there are
only two or three things that pop up, and one of those is one of my conference posters,”
Hitchcock said.
Landfills and litter were long thought to be major sources of microplastics in water,
however recent studies from other states have found that wastewater treatment plants
can actually add more plastic to the water coming through its facilities.
There are various reasons for this. For example, vehicle tires will shred tiny pieces
of plastic onto roads as they drive, and rainwater sweeps this into leaky wastewater
pipes. Microscopic pieces of plastic can even come from clothing being washed in a
washing machine. The water drains into the sewer system, taking the microplastics
with it. Many wastewater plants may not have the right processes to remove these microplastics.
“Nobody has done a study on if and how much wastewater treatment plants are contributing
microplastics to Tennessee’s aquatic ecosystem,” Datta said.
Hitchcock, Datta and Murdock’s research has two main objectives: develop standardized
methods to sample, analyze and detect microplastics in wastewater, and apply those
methods to investigate microplastics in wastewater treatment plants in Tennessee.
Hitchcock started her research as an undergraduate student. Because not many other
studies had been accomplished in wastewater, she began investigating the literature
for various techniques to sample for microplastics and attempted to recreate them.
“When you look at the microplastics research in wastewater, they often won't detail
the methodology so that it's replicable,” Hitchcock said. “So, it's very complicated.
It’s been sort of a trial-and-error process since the beginning.”
Now as a graduate student, she has spent her time discovering the best techniques
for detecting microplastics in wastewater samples. She will continue to collect and
analyze samples through the end of this year to investigate if different seasons,
treatment processes, or status of sewage infrastructures make a difference in her
results.
The facilities at the Water Center at Tennessee Tech have been especially helpful,
Hitchcock said, for procuring a FT-IR microscope and allowing her to use it for experimentation
and analysis.
Hitchcock’s research is set to not only provide valuable insights on microplastics
in Tennessee’s waters, but to also give her experience and knowledge that she will
take with her once she graduates and heads off to her own career.
“I really found a passion in water,” she said.