Harmful Effects of Plastic and Biodegradable Plastic, Garbage in, Garbage Out, Class 6 Science Video Lecture | Basic Science for Primary 5

in the previous video limits to
recycling we looked at the overall
limits to recycling of materials we
touched on plastics in their video you
may be aware that the biggest problem in
recycling plastics is they are not
biodegradable so that soft drinks bottle
or your wrappers that you just throw
away and not biodegradable
this means the fate of most plastics is
to go into landfill sites or our oceans
where it will take hundreds possibly
thousands of years for them to degrade
you may say what about recycling briefly
the problems with recycling plastics are
they have to be manually sorted which is
a labor and energy intensive process mix
polymers are found in a range materials
so cannot be recycled and are often
dumped once a plastic has been recycled
once it can be come down cycled whereby
its quality is decreased the fact is
that plastic recycling rates are far
below other recycling rates but the
industry has improved in recent years
worldwide seven groups of plastic
polymers have been given a plastic
identification code that people use for
recycling these you can find the most
packaging or plastic materials different
types of plastics will be recycled by
different municipalities even by
different countries in some instances
generally it's difficult to recycle
plastics with numbers one and two
plastics in these higher numbers are
known as rigid plastics so the disposal
of plastics is a tricky one other than
reducing their use recycling or reusing
them what else do you think might be
done to dispose of them pause the video
and continue when you think you have an
answer
one way is that the plastic can be
incinerated or burn whilst this produces
useful energy some plastics contain
polymers that are halogenated when these
polymers are burnt for instance PVC
toxic fumes like hydrochloric acid are
released this can cause severe
respiratory distress and so is hugely
problematic in addition burning of
polymers produces co2 the greenhouse gas
also contributes to global warming this
is because about 10% of the oil is used
as petrochemicals if we then use the
polymers again as a fuel for energy
production then at least we're using the
oil twice you may have heard the idea of
using bio plastics as a solution but
these two can have problems what do you
think bioplastic is pause the video and
resume when you have an answer a blyer
plastic is a biodegradable plastic
this means it's compostable and it can
be broken down by the result of
bacterial action when it is disposed of
whilst this is a benefit there are still
issues with bio plastics that need
solving bio plastics often come from
renewable raw materials like starch
maize cellulose and poly lactic acids
these are plant derived materials and so
the ethical question arises is where the
land should be used to grow crops or
bioplastic manufacture instead of crops
for food originally we said that bio
plastics are readily compostable
however bio plastics are not nearly as
readily compostable as regular plant
material if you toss a bio plastic fork
into your compost and assume it will be
dirt in a few months you'll be
disappointed why last a bioplastic
fork is compostable it requires high
intensity high heat commercial
composting for that to happen quickly
in summary plastic disposal has a number
of issues with regards to landfills
recycling and insid eration however bio
plastics so slightly better do not
present themselves as the better
alternative because there are issues of
land usage the quality of the buyer
plastic and how it is composted
the best alternative is to reduce our
usage and disposal of plastics all
together
you