Environmental Engineering Reference
In-Depth Information
What can be done about PPCPs?
Education is a major approach to pharmaceutical pollution.
“Don't Rush to Flush” became the motto used to teach the
public about the risks of flushing or improperly disposing of
unwanted or unused over-the-counter medications, pharma-
ceuticals, and personal care products. However, most of the
problem is not due to unused medications improperly flushed
down the toilet, but those that were taken properly and later
excreted in urine. Conventional methods of filtering waste-
water in sewage treatment plants can't completely remove
medicine residues. New technologies for treatment plants
are needed, but not yet ready for use. Chemical processes are
being devised and tested that can remove persistent chemicals
and pharmaceuticals from wastewater. Pollutants can also be
removed effectively from wastewater with selective adsorb-
ers. A  biological filter has been developed in which specific
enzymes (called laccases) break down pharmaceuticals. These
are still in the experimental stage and have not been put to
use anywhere, but provide an idea as to approaches that can
be taken. Another new water treatment technology called
membrane distillation separates drug residues from sewage
by heating. Water vapor passes through a thin membrane and
through an air gap, where it condenses onto a cold surface.
Drug residues collect on one side of the membrane and water
on the other. In a test with oxazepam in wastewater, the level
was reduced to less than 1% of the original concentration. This
technology is also in the very early stages of development.
What are polybrominated diphenyl ethers (PBDEs) and why are
they a concern in the marine environment?
Other emerging contaminants are flame retardants that are
used in a variety of consumer products including clothing,
furniture, curtains, carpets, and toys. They are intended to
slow the rate of ignition and fire spread, giving people time
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