What Are Plastics Review Environmental Impacts of Plastic Use
Plasticizers:
PCBs (Polychlorobiphenyls)
Phthalate Esters (most important
plasticizer used now) (omnipresent environmental contaminant)
Fossil Fuel Use
most plastics are made from petroleum
crude oil -> distillation, cracking
-> monomers for plastic (ethene, propene)
Fossil Fuel Transport
oil tankers pipelines oil drilling off
shore oil drilling on land, wilderness areas etc.
Energy Use
energy needed to make plastics more fossil
fuel used, CO2 emissions, greenhouse effect
Disposal
production > 200 lb/year/person 20 %
volume, 8 % weight of municipal landfills are plastics often end
up in the environment outside of landfills marine environment
! Most plastics float -> Remain mobile
for a long time !
86 % of trash floating in North Pacific
Ocean was plastic
FISHING LINES, LOBSTER TRAPS, NETS, ROPES, PLASTIC STRAPPING, BAGS, SHEETING, PLASTIC PELLETS, SIX-PACK RINGS - seals and seabirds strangled in rings of six-pack holders - 1982: 50,000 northern fur seals per year due to entanglement - sea turtles eating plastic bags mistaking them for jellyfish (6 of 7 species), 2 lbs of plastic in 11 lb turtle - dolphins getting entangled in abandoned drift nets, discarded fishing gear - whales die from eating balloon - 99 of the worlds 312 species of seabirds have been shown to ingest small pieces of plastics
Degradation
most plastics are non-degradable and take 200 - 400 years to degrade
some plastics are photodegradable (turn yellow in sunlight), by incorporation of C=O group in chains -> adsorbs light (zipper effect) ! does not work when plastic is buried !
Incineration
waste plastics can be burnt to get energy
PVCs give up HCl Polyurethanes give up HCN CO2 (greenhouse gas)
CO (toxic) Soot other toxic trace gases (PAHs, nitro-PAHs, PCDDs,
PCDFs)
Recycling
87 % of all plastics are thermoplastics,
can be melted or remolded must first separate currently, only 2 % recycled
Degradable Plastics Plastics made from carbohydrates, proteins, carboxylic acids Monomers are derived come from the fermentation of crops Eco-foam from starch, water soluble (to replace Styrofoam peanuts)
http://www.tamucc.edu/~whatley/padm5370/whatis.htm
What is Marine Debri