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Andrea Roberts, visiting instructor of chemistry, has introduced "green"
techniques into her organic chemistry laboratory sections. Students use
fewer chemicals, producing less waste. |
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| Posted 06.20.07 |
Chemistry Lab Has New Environmental Perspective
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At first glance, Wesleyan’s Organic Chemistry Laboratory doesn’t appear much
different to the naked eye. But a closer look shows that virtually
everything in the lab has changed.
“We’re going green,” says Andrea Roberts, visiting instructor of chemistry
and Ph.D candidate. “We’re promoting sustainability and teaching the leaders
of tomorrow better ways to do chemistry.”
Roberts started teaching the organic chemistry lab in Spring 2004, using a
routine syllabus. The class had nine weeks of typical organic reaction labs
and one, three-week final project.
“The Chemistry Department had been teaching the same organic chemistry
curriculum for years,” Roberts says. “Some of the organic reactions students
were doing were the same ones I did as an undergraduate. Although they were
tried and true, they were becoming outdated. Very few industries nowadays
are performing chemical reactions the way we were teaching them, and our
experiments were producing a tremendous amount of chemical waste.”
In Spring 2007, Roberts made changes to the curriculum that allowed her to
teach the same material using “greener” methods. This meant minimizing
materials – chemicals, solvents and testing equipment; reusing or recycling
materials in the lab; replacing harmful mineral acids and organic solvents
with less toxic oxidants like peroxide and alcohols as solvents ultimately
minimizing waste.
She began with the lab titled Introduction to Chromatography. For this task,
students needed to separate a mixture of two compounds, fluorene and
fluorenone.
Students previously used a gravity-based technique called column
chromatography to separate and purify the chemical compounds. This slow
method required .5 grams of fluorene and fluorenone to pass through a tube,
or column, of 10 grams of silica gel. About 200mL of hexane was used to
separate the compounds.
Roberts replaced this old-fashioned method with flash chromatography, a
rapid method that pumps solvent through a cartridge, leading to quicker
separations with less chemical waste. She replaced the fluorene and
fluorenone with drops of water-soluble food coloring and used only .75 grams
of silica, which later is recycled. Only 10mL of isopropyl alcohol is used,
rather than hexane.
Roberts is able to recycle used silica gel in-house. As a result, no solid
waste is generated in this experiment and only 10mL of alcohol is output as
liquid waste.
Experiments with organic chemistry, a branch of chemistry that focuses on
the properties and reactions of carbon-containing compounds, have the
potential to be bad for the environment, explains Bill Nelligan, associate
director of Environmental Health and Safety. By going green, Nelligan
estimates the lab has reduced its solid and liquid waste by 50 percent each.
According to EPA guidelines, waste must be documented and discarded
properly. These chemicals are sent to EPA-permitted Treatment Storage and
Disposal Facilities for disposal or to be used as fuel in energy conversion
plants.
“Wesleyan owns all chemicals, from the time they are brought into the
university, to the time they are used, and from the time they are recycled
or end up in a hazardous waste facility or landfill,” Nelligan explains.
“Chemicals are a cradle to grave responsibility.”
Roberts began the quest to go green in Summer 2006 when she met with
Margaret Kerr, who received her inorganic chemistry Ph.D. from Wesleyan in
1998. Kerr is currently an assistant professor of inorganic chemistry at
Worchester State College and an expert on green chemistry.
Kerr directed Roberts to the online database, Greener Education Materials
for Chemists. This site features an interactive collection of chemistry
education materials focused on green chemistry.
“I was able to find the same lessons using green chemistry and plug them
into our curriculum,” Roberts says.
Organic Chemistry Laboratory is a required course for anyone majoring in
chemistry or pre-medical, dental and veterinary studies. The updated,
environmentally-friendly course, CHEM 258, has increased student enrollment
25 percent over the last few years. Roberts teaches six sections comprising
no more than 20 students each.
By going “green,” Wesleyan is taking part in the U.S Environmental
Protection Agency’s Green Chemistry Program. Green Chemistry Program has
built hundreds of collaborations with academia, industry, government
agencies, scientific societies, trade organizations, national laboratories
and research centers to promote the use of chemistry for pollution
prevention through completely voluntary, non-regulatory partnerships.
Next fall, Roberts will co-teach the laboratory-based Integrated Chemistry
course Chem 375 with Albert Fry, professor of chemistry. Roberts plans to
introduce green chemistry concepts to the lab.
“If we just focus on being one university going green, in one state, in one
country, we are doing our part,” Roberts says. “Wouldn’t it be wonderful if
every university in every state did their part? Imagine the impact.”
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By Olivia Bartlett, The Wesleyan Connection
editor |
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