Waste management is literally the difference between oceans growing in plastic and perfectly green economies!
Yes, I know… what an unbelievably boring way to start off an article! But… what if you realised that waste management is very misunderstood and is actually really interesting? Like setting mountains of garbage on fire and liquifying it interesting!
This is important because waste management technology is one of THE biggest parts of whether our waste ends up being recycled to save the turtles or being thrown in open dumps in developing countries where it washes into oceans! To give context to that, it makes sense to talk about the three waste management technologies people usually imagine: landfills, recycling, and incineration. We’ve been developing more of the last two recently:
But of course, we’re most familiar with the first. With landfills, you’re just burying garbage in a (hopefully) safe manner. Nothing too fancy, although sometimes you can extract methane from the decomposing garbage.
Then, you get a little more complex with recycling. In North America, it’s often run by municipalities and the waste that gets recycled varies a lot. Sometimes metals, paper and paper are recyclable… most often a few types of plastic (like PET) are too.
And finally, you have incineration. Literally just taking whatever waste you have and burning it to get rid of the material. Sometimes, you use the heat generated to boil water, get steam, spin a turbine, and get electricity.
That’s fairly well known, but what we don’t often realise is how all these technologies fit together in a waste management system. To highlight this, consider your friendly neighbourhood garbage/recycling trucks picking up waste from different types of bins.
Here’s the first big relationship — right at the very source, the material that goes in the recycling bin is taking away from the material that typically winds up in a landfill/incinerator. This is a good thing. Although studies show different results, the environmental impact is usually lower for recycling than other waste management technologies (Source).
BUT as we follow the recycled waste to recycling facilities (fancy name: Materials Recovery Facilities or MRFs), not all the waste collected from ‘recycling’ bins is actually recyclable. Materials like metals or glass (if they’re collected) often are. Paper-based products can also be recycled easily if they’re not mixed in with other materials (Source).
But when it comes to plastics specifically, a surprising number of ‘recyclable’ plastics actually can’t be recycled at these recycling facilities and get sent to landfills or incinerators.
The first major issue is with the type of plastic involved. Many plastic polymers lose quality every time they’re melted (part of most recycling processes). This happens because their molecules shorten in length when melted (Source).
Asides from many TYPES of plastic not being recyclable, their SHAPE matters too! For instance, plastics in thin films like from packaging or small single-use plastics often get caught in machinery in recycling facilities (Source). And then we also have plastics contaminated by other material, such as food residue.
So not everything you put in the recycling bin can actually be recycled. All these unrecyclable materials contaminate the input received by recycling facilities and are can cause entire batches of plastic (only some of which is contaminated) to be sent to landfills or incinerators.
Combining that with waste that already goes to landfills or incinerators, the recycling rate for municipal waste was under 10% in the US in 2019 (Source). In comparison, 38% of plastics in Germany were recycled in 2018 (Source). In any case, MOST waste isn’t recycled and is sent elsewhere.
This is the key part about these typical waste management technologies — more of one means less of the others, because the waste can only go to EITHER landfills OR recycling facilities OR incinerators.
As mentioned earlier, recycling is the most environmentally friendly option, but it doesn’t work for ALL kinds of waste (especially when it comes to plastics). In many municipalities in North America, the waste that isn’t recycled is sent to landfills.
This has a few advantages: for one, you don’t run out of land area when you’re burning waste instead of burying it. And when you burn plastics, you can generate energy with the heat released. Also, with modern incinerators, emissions scrubbers effectively deal with byproducts of burning plastics. Many studies show that incinerators are greener than landfills (Source).
There are also issues, however. For one, incinerators require high initial investments in the tens of millions of dollars, so they need to operate for decades before they’re profitable. They also face increased costs when they implement new measures to meet environmental regulations. In Texas, the costs of incineration can be up to $300 / tonne of waste, whereas the cost of dumping in landfills was $35 / tonne (Source).
Additionally, incinerators are not as green as recycling facilities, so investing in these incinerators for the long term decreases the ability to build up recycling infrastructure over time (Source). According to Professor Thomas Kinnaman at Bucknell University, after developed countries have more than 40% of waste sent to incinerators, recycling rates start to decrease.
So all th target="_blank"ese existing technologies have some benefits and trade-offs:
- Recycling: the most environmentally friendly option, but doesn’t work with all waste and can be expensive.
- Landfills: have environmental costs and are increasingly more expensive and unpopular.
- Incinerators: have somewhat lower environmental costs and can create energy from waste, but have high costs in the long term.
BUT this is an incomplete picture for two reasons. First of all, those technologies have been around for decades and by now, we have more options being implemented. Then, these technologies really only exist in developed countries. Things look COMPLETELY different in developing countries like China or the Philippines.
First, what about newer technologies in development? These are mainly forms of waste to energy (WtE) systems — like incineration. The key difference is that they all generate chemical fuels from waste instead of burning it. Three types of fuels that can be generated are oils, synthesis gas, and combustible waste mixtures.
None of these new technologies are deployed at scale right now. For instance, when it comes to generating synthesis gas (via a process called gasification), only a small fraction of technology is able to create this end product with WASTE materials instead of processed petroleum products.
That being said, there is progress being made on these new technologies. In the future, other waste to energy technologies might replace incineration (although perhaps not recycling). For instance, Enerkem is currently a promising company in the gasification industry in developed countries, while Ocean Conservancy recommends creating combustible waste mixtures from waste materials in developing countries (Source).
Then comes the HUGE issue. Neither these newer technologies nor traditional waste management systems are what reality looks like in developing countries (as opposed to developed countries with friendly neighbourhood garbage trucks). This is how waste management looks like in developing countries instead:
Instead of having recycling or garbage trucks to collect waste and bring it to nice orderly waste management facilities, many developing countries (especially in Asia) rely on open dumps to deal with over 25% of their waste (Source).
Informal waste pickers scour these open dumps to find materials they can resell. There’s an entire informal economy of dealing with waste that ends up in open dumps (Source ). But open dumps aren’t a great ‘technology’ to deal with waste in any way except that they’re cheap.
Looking at the environmental costs of open dumps, their waste material is more likely to end up as pollution— often via chemical leakage into the environment and sometimes by ending up in water bodies. This means the waste is ‘mismanaged’ — and the majority of mismanaged waste comes from the Asia Pacific region. For example, with mismanaged plastic:
The problem is that any other form of waste management is hard to establish in developing countries — due to the high costs, due to technological and infrastructural limitations, and due to disruptions in existing informal waste management economies.
But since such a large portion of the issues with pollution come from developing countries, they’re the key areas that NEED feasible waste management technology to work in a cheaper, more environmentally-friendly and more scalable manner.
Turns out, it’s surprisingly interesting to compare the advantages and disadvantages of the technologies involved in waste management:
But the core issue that ALL of these technologies have to get better at is scaling from the ideal suburban neighbourhoods of developed countries to where they could have the MOST impact — in mountains of unkept waste in developing countries. And that’s one of the MOST interesting hidden challenges you could hope to find in a seemingly boring industry.