You do your bit. You put everything that can be recycled into the appropriate bin. You know that if it’s plastic, it’ll probably end up being made into a bottle or if it’s an old newspaper and magazine, one day it will be made into new paper. But how does it all happen? What is the recycling process really like?

If you live in Glasgow, the chances are your recycling will end up here, at Blochairn Materials Reclamation Facility, just off the M8. The facility is the end point for all the blue bins that are collected across the city and that means a lot of rubbish: some 17 to 35 trucks at the start of every week: 50-80 tons a day, 500 tons a week, 25,000 tons a year.

Once it’s been dropped off, the waste then goes through a sorting process, which is a mixture of automation and sorting by hand. The aim is to eliminate the stuff that cannot be recycled and, stage by stage, sort the rest into different categories so it can be recycled. It’s loud, it’s messy, and for the staff who do it, hard work. This is how it happens.

STAGE ONE: THE DROP-OFF

It’s first thing on Monday morning and Glasgow’s recycling trucks are delivering the rubbish they have collected from all over the city and dumping it into one big mountain of trash. Monday is the busiest day here, and January the busiest month, so there’s a lot to get through.

The mountain is huge – about 20ft high – and represents just three days of waste from Glasgow, from around 300,000 people. And this is just the stuff from the blue bins – about 75 per cent of the waste we throw away ends up in landfill.

In theory, all the rubbish that has arrived here this morning can be recycled but we can see straight away that there’s lots in this pile that shouldn’t be there: polystyrene, bin liners, wood, plastic cartons, children’s toys, an old tent, and hundreds of thousands of other unrecyclable items, which people have accidentally, carelessly or thoughtlessly chucked in the blue bins. About 25 to 30 per cent of the material dropped off here cannot be recycled.

The staff also regularly find weird and gruesome things in the rubbish. Microwaves. Fire extinguishers. Brake pads. A dead snake. Two dead deer. A bag of dead rats. And on one occasion, an iPhone (the owner tracked it to the Blochairn facility and, luckily, the staff found it, after it had gone right through the machinery. The only damage? A tiny scratch on the front).

“If you can fit something in a bin, people will put it in a bin,” says Rolf Matthews, who is the waste manager here. “The biggest frustration is people putting wrong stuff in the bin, and it can be unpleasant wrong stuff.”

Standing in front of the huge pile of rubbish, councillor Anna Richardson, the city convener for sustainability and carbon reduction, says in some ways seeing so much waste is depressing, but at least something is being done.

“If it has to be somewhere, I’m glad it’s here and I’m glad we’re doing something, but we have to reduce the amount of stuff that we consume in the first place,” she says. “This can’t carry on – it’s completely unsustainable.”

STAGE TWO: SORTING BY MACHINE

Now the real sorting begins. A huge mechanical loader picks the rubbish up and drops it into the first piece of machinery: a bag splitter, which will remove any plastic bags that are still around the rubbish. The second stage is to remove material which should go to landfill. The machine then sorts the material by size, separating any paper and cardboard.

The next stage is to sort the waste into different types, which the machine does in stages using different techniques. Magnets are used to separate out tins and cans; the machine also scans plastic to divide it into two categories: the opaque high-density polyethylene used in milk bottles, and the rest.

The machinery also sorts out the material that cannot be recycled, which is around a third of the total. It has probably been put there by people who are well-meaning or simply don’t understand the rules, but, if in doubt, check the sides of the blue bins where it is made clear what can and can’t be recycled. In Glasgow, you can put the following into the bins: newspapers, magazines, office paper and catalogues, phone directories, junk mail, food tins and drinks cans, aerosol cans, plastic bottles, white envelopes, cardboard boxes, and packaging. And you cannot put in the following: plastic bags, foil, margarine tubs, glass bottles, brown envelopes, tetra pak cartons, paint tins or plant pots, or yoghurt pots.

Councillor Anne Richardson understands that people sometimes get it wrong. “Even in my house, we had been putting things into the bins thinking they were recyclable – I learned here that there were things that we should be putting in the general rubbish. Some people still don’t want to recycle but even among those that do, it can be complicated and I think we need to do everything we can to get that message across clearly.”

STAGE THREE: SORTING BY HAND

Having been sorted by machine, the waste now arrives on two belts into a sorting room where some 14 staff sort the rubbish by hand. I have a go and it is not easy: the belts are fast-moving and the aim is to remove the tins and plastic from the paper and put the material in separate bins. Quite often, the belt suddenly stops because there is a blockage in the machinery that has to be removed by hand. Otherwise, the belt keeps going for seven to eight hours a day.

One of the staff working today is Charlie Miller. “It’s a long day but I’m used to it,” he says. “I used to sweep the streets for a while, but I prefer this. A lot of guys don’t like it but I do. It’s not tiring, just boring. A lot of people are chucking out stuff they shouldn’t.”

His colleague, Steven McKay, 33, is the one who shows me the ropes. “It’s not hard and it’s not the worst job,” he says. “I’ve seen worse and dirtier jobs than this, like the bin lorries. I used to be on the bin lorries every day – that’s hard. And you are doing something for the planet, aren’t you? The pay is ok but there aren’t enough people.” The staff tell me that, fully manned, this place should have 24 people – usually, there are around 14-17.

For Anna Richardson, this part of the process should act as a reminder for all of us about what recycling is all about. “There are guys who do this as their day job,” she says, “picking through the rubbish that we throw away and we should think a wee bit more about how we could make their job easier when we are in our kitchens.”

STAGE FOUR: THE DUMPSTERS AND THE BALES

Now that the rubbish has been sorted by machine and then by hand, the material is dropped into several huge dumpsters. There is one for plastic, one for milk bottles and other bottles, one for tins, and one for the rest: all the stuff that cannot be recycled.

The material is then sorted into bales ready to be taken from Blochairn to the final stage. Paper is sent to a mill in England for reprocessing; aluminium is sent to a processing plant in Warrington where it is melted down and re-used; plastic goes to three different plants in England, where it is shredded, cleaned and re-used. Plastic tends to be re-used in non-food bottles; it can also be turned into clothes, like the yellow jackets we are wearing on the site.

As for the waste that cannot be recycled, that is exported to Scandinavia, where it is burned to produce electricity. At the moment this is something that cannot be done in Scotland, but that will change when a new facility at Polmadie in Glasgow opens. The £154m scheme is expected to divert 200,000 tonnes of waste from landfill each year, providing renewable energy that will power 22,000 homes.

At Blochairn, the bales of rubbish are sold on, which does earn Glasgow City Council some cash, although it is nowhere near enough to offset the total cost of dealing with the city’s rubbish. The bales of milk bottles for example are sold for £240 a ton, but if people recycled better, meaning there was less contamination, they could get more.

Standing in front of the bales, Paul Clayton, the transfer station supervisor, tells me that, slowly but surely, we are getting better at recycling. “I think we are going in the right direction,” he says. “There are a lot more people recycling.”

But the problem as far as Councillor Richardson is concerned is that we are still not thinking enough about what happens to our waste. “As a society, we are really disconnected from our waste,” she says. “We put it in bins and then pretend it never happened or that we never created it. That cannot go on.”