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, the plastic of some kind. And plastic takes hundreds of years to decompose. All this junk litters our planet and lots of it end 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 the 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 meters 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 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 recognize the different types of rubbish. This one is set to ‘see’ soft plastic film and when it sees some approaches, it triggers a jet of air that hits the item as it crosses the end of the belt, blowing it on to another belt behind. It’s very fast but watches 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 that 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 which removes all non-ferrous metals such as aluminum — 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. The 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 that 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 the 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 organize 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!