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The world is under threat. Not from aliens or terrorists or nuclear bombs, but from something
much less obvious. For millions of years nature was in charge
of the earth and all the waste from animals and humans would rot down and turn into soil.
Soil helped to make the things grow for the animals and humans to eat so for millions
of years, it was the perfect recycling system. But then, just a few hundred years ago, humans
started to make more and more things so there was just too much for nature to cope with
and rubbish started to be a problem. This was bad enough but around 1860 plastic was
invented and now almost everything we buy: cars, computers, toys and food, is either
made from, or wrapped in, plastic of some kind. And plastic takes hundreds of years
to decompose. All this junk litters our planet and lots
of it ends up in the sea. In the middle of the Pacific Ocean there are two islands of
rubbish that together are over five times the size of the whole of England. No-one has
worked out how to clean them up so they're just getting bigger.
On land, rubbish that isn't recycled goes into enormous pits called 'landfill'. These
pits are filled to the top with rubbish and then covered over. But as the rubbish rots
it produces lots of a gas called methane. Methane is what is known as a 'greenhouse'
gas. Too much greenhouse gas changes the world's climate and makes it hotter. Also, nasty poisonous
liquid leaks out and this has to be treated like sewage to make it safe. Yuk!!
In Devon alone, the amount of rubbish going to landfill weighs around the same as seven
thousand, six hundred and eighty two Jumbo jets! What doesn't find its way to landfill
is left around on the streets, in the countryside and on beaches where it not only looks horrible
but it's a real danger for wildlife. One plastic carrier bag can split into lots of pieces
and if animals, birds or fish swallow these, it may choke them.
Small creatures can get stuck in discarded bottles and cans and drown or starve. When
it's hot, glass bottles can start fires, destroying huge areas of countryside.
Much of what ends up in landfill could be recycled and people are now being encouraged
to recycle more of their household waste. But it isn't just rubbish from our homes that
finds its way to landfill, there's a huge amount that comes from shops, offices, factories
and other businesses. Up until now businesses have had to sort all
their rubbish for recycling but many didn't have the time, which is why much of it ended
up in landfill. However, help is now at hand! In Exeter, there is a place called Envirohub,
which is the base for Devon Contract Waste. This company has started a 'Zero to Landfill'
campaign because they would like to see everything recycled so landfill wouldn't be needed anymore.
To help with this, they have spent over four million pounds on a fantastic new waste sorting
machine which means businesses won't have to sort their rubbish anymore.
This machine is huge: it's over ten metres high, covers the same area as one football
pitches and it can sort up to 300 tonnes of rubbish per day -- that's the same weight
as thirty seven and a half full size elephants. So how does it work? Let's go and see it in
action! Rubbish arrives at Envirohub from all around
the county in dustcarts, front-loaders and wheelie bins, where it is all emptied out
on the floor. Then it is lifted by this mechanical grabber and dumped into the hopper where it
is shredded down into smaller pieces.
From the shredder, the rubbish goes up this belt to a big drum called a trommel screen.
This tumbles the rubbish to remove all the soil and dust which gets turned into a fuel
called Refuse-Derived Fuel product -- or RDF for short. Nothing gets wasted here!Everything
else continues on to here. This is called a ballistic separator and it walks everything
upwards, but only the flat material makes it to the top. The three dimensional items
can't manage the climb and fall back onto another line below.
The flat stuff now falls onto a belt which goes under the first optical sorter. This
is a line of small cameras that can recognise the different types of rubbish. This one is
set to 'see' soft plastic film and when it sees some approaching, it triggers a jet of
air which hits the item as it crosses the end of the belt, blowing it on to another
belt behind. It's very fast but watch closely and you'll see the plastic flying off. That's
amazing! This rubbish left on the belt drops down to
another below. It then passes the second optical sorter, which is set to 'see' all paper and
card products. It's very important that nothing else gets through so just to make doubly sure
there are two people inspecting it. Remember the 3D stuff that didn't make it
to the top of the line earlier? Let's go and see what happened to it. Here it is, going
past a very powerful magnet which attracts all ferrous metal -- that's metals like iron
and steel which are magnetic. Everything else won't be attracted by the magnet so goes on
to this eddy current machine [maybe explain how this works?] which removes all non-ferrous
metals such as aluminium -- things like drink cans. All the metals are collected in the
skips below. The non-metallic material left on the belt
then goes twice past another optical sorter. The first time it puts all plastic on one
side and the second time it puts all paper and card on the other. Anything left over
will also go into the fuel product or RDF we mentioned before.
Under the machine are all these bays where the different materials end up. The contents
are eventually baled and wrapped like this ready to be transported.
What an amazing machine! So where does it all go? The metal will be
sent to be melted down so it can be made into other metal products. Paper will be recycled
into tissue such as toilet roll and hand towels. Plastics are recycled into new products; some
obvious ones such as carrier bags and bin liners, but also fleeces, umbrellas, children's
toys and even car bumpers. Card is generally shipped to China for recycling. This goes
on ships that have delivered products from China into the UK, and need to return anyway,
so it is reasonably environmentally friendly. People like those at Envirohub are working
really hard to try and reduce the enormous problem of how to cope with all the rubbish
we make, but everyone needs to do their bit. If they don't, then the risk of long-term
climate change which would make parts of the planet impossible to live in, is very high.
So what can you do? Never drop litter -- remember it doesn't just
look horrible, it's a danger to wild and domestic animals. If there's no litter bin, then take
it home. At home, help your parents with recycling
your rubbish. If you have a drink from a can, put it straight in the recycling bin and save
your mum having to do it. Do the same with paper and card. (Better to let your parents
deal with glass bottles though). Learn about which plastics are recyclable
- they should have this symbol on them if they are. Make sure they go in the plastics
recycling. Be careful not to put things in that don't have the symbol because that will
spoil a whole load and may prevent it from being recycled. You can also recycle clothes,
mobile phones, and most old toys. Every little bit that goes in the recycling bin means less
in landfill. Be careful with old batteries -- when they
start to decompose, poisonous chemicals leak out. Take them to your local waste recycling
site and put them in the special bin provided. These things really do make a difference -- if
everyone did them we'd be well on our way to solving the problem. But if you want to
do something on a bigger scale, why not see if your class or scout or guide group could
organise a litter pick? Especially if you live near a beach or public area this is a
great thing to do. When places are clear of litter, it discourages other people from dropping
it. Do make sure there are adults in charge though.
Previous generations have failed to heed the scientist's warnings but you and your friends,
along with people like those at Envirohub, can help to clean up the mess they have left.
We are all very lucky to live somewhere as beautiful as Devon. Let's do our best to keep
it that way -- and at the same we will be helping the whole planet!