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The Engineering of Landfills

practical.engineering

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Re: The Engineering of Landfills

#51

Post by bredren »

scoofy wrote: post #34
ajb wrote: post #33

"trash is an inescapable fact of the human condition" Not really. There didn't used to be anything like as much. But what we did before wasn't necessarily better. Most consumer products were made of organics, like wood, cloth and paper; metals, and clay. Organics were burned or recycled, metals recycled (as now). Only broken clay was really waste. Cities didn't collect trash - they collected ash. In Britain waste col…

If you don’t think humans used to make trash, I have plenty of shell mounds to show you.

Reminds me of this 2013 report on the earliest cat domestication (~3610 BCE):

> The felid bones were found in an ashy matrix in three refuse pits, H172, H35, and H130, with animal bones, pottery sherds, bone tools, and some stone tools...

https://www.pnas.org/doi/full/10.1073/pnas.1311439110

Re: The Engineering of Landfills

#52

Post by [deleted] »

newsclues wrote: post #15
bko wrote: post #2

I found this interesting: > Another option is to put it to beneficial use to create heat or even electricity. The Puente Hills landfill I showed earlier has a gas-to-energy facility that’s been running since 1987, and even though the landfill is now closed, it currently provides enough electricity to power around 70,000 homes. And towards the end > Landfills seem like an environmental blight, but really, properly des…

[flagged]

[deleted]

Re: The Engineering of Landfills

#53

Post by mikojan »

daedrdev wrote: post #38
mikojan wrote: post #26

Earlier quoted context omitted.

Landfills certainly require more power to operate than that gas scheme can provide later. It all sounds and reads like a fairytale but none of this is sustainable.

The gas is generated by the chemistry of the stuff that was put there. Moving the stuff there takes a lot of energy, but everything sitting there mainly just needs a pump and treatment system.

This is besides the point because environmentalists (who were carped at above) tend to seek to reduce the amount of trash that needs to be shipped off to somewhere.

Re: The Engineering of Landfills

#54

Post by ngruhn »

gruez wrote: post #27
the_gipsy wrote: post #16

Earlier quoted context omitted.

I'd guess that it's cheaper to ship a lot of garbage to developing countries.

Is it? Land is dirt cheap in the US. Surely it's cheaper to bury it locally than ship it half way across the world? Even for the plastic that's being shipped half way across the world, they're ostensibly done for recycling purposes (ie. they're buying the plastic waste), and the unrecycleable plastics end up being mismanaged.

I’ve heard, shipping a lot of garbage to China was quite common until the Chinese banned it. That was economically viable because China exports so much and many container ships would otherwise return empty to China.

Re: The Engineering of Landfills

#55

Post by whycome »

AndrewKemendo wrote: post #50

I started a residential trash hauling cooperative this year after 7 years of planning Yall have no idea how much opportunity there is here

I've seriously wondered about this. Tell us more. Do you just act as a private middleman to get things to the dump? Do you sort or resell?

Re: The Engineering of Landfills

#56

Post by breck »

cm2012 wrote: post #9

So many people misunderstand landfills. All the garbage produced in the U.S. for the next 1000 years could fit into a landfill 100 yards deep and 35 miles across on each side. That is, landfills take a trivial amount of space. Putting stuff in a landfill is way better for global warming since its not burned, the carbon is buried. Almost all plastic waste in developed countries ends up in landfills, not the natural en…

> All the garbage produced in the U.S. for the next 1000 years could fit into a landfill 100 yards deep and 35 miles across on each side.

> That is, landfills take a trivial amount of space.

Damn, I had to think about this for a second, but you are right.

How the hell did I not realize this before?

Can you please popularize this more? Maybe compress into a pithy phrase.

Re: The Engineering of Landfills

#57

Post by rtkwe »

throwup238 wrote: post #46
mikojan wrote: post #40

Earlier quoted context omitted.

A single truck requires more energy to operate in a year.

According to [1] an electric garbage truck traveling 15,000 miles a year uses about 38,960 kWh. An 84 MW power plant produces 84,000 kWh every hour, or enough to power more than two trucks for an entire year. Even if we assume that the diesel equivalent uses a hundred times as much it's still a tiny fraction of what the plant in TFA produces. [1] https://www.oregon.gov/deq/ghgp/Documents/ElectricGarbageTru...

Couple issues with that comparison: 15k seemed low given I drive ~10k a year and I don't work a job that uses my car, so I checked refuse trucks drive on average more like 25k miles per year and there are many servicing a single dump. Also most garbage trucks are still diesel so you've got to 5-10x that power usage number and there's all the vehicles used to compact and move the trash once it reaches the landfill which are also (currently) pretty exclusively diesel powered (think bulldozers and soil compactors with some excavators thrown in).

https://afdc.energy.gov/data/10309

Re: The Engineering of Landfills

#58

Post by coding123 »

gosub100 wrote: post #44
mikojan wrote: post #26

Earlier quoted context omitted.

Landfills certainly require more power to operate than that gas scheme can provide later. It all sounds and reads like a fairytale but none of this is sustainable.

This is my argument against recycling. It is not sustainable to recover a tiny amount of energy when balanced with the extra diesel-guzzling truck traversing the neighborhood. All so we can think we're "making a difference" by keeping plastic bottles out of a landfill.

Maybe someone should write a book about virtue signaling and it's dangers.

Re: The Engineering of Landfills

#60

Post by renhanxue »

cm2012 wrote: post #9

So many people misunderstand landfills. All the garbage produced in the U.S. for the next 1000 years could fit into a landfill 100 yards deep and 35 miles across on each side. That is, landfills take a trivial amount of space. Putting stuff in a landfill is way better for global warming since its not burned, the carbon is buried. Almost all plastic waste in developed countries ends up in landfills, not the natural en…

> Almost all plastic waste in developed countries ends up in landfills, not the natural environment.

Here in Sweden less than 0.5% of household waste goes to landfill. Almost everything is burned in co-generation plants for district heating, with pretty sophisticated exhaust gas treatment. Unfortunately most of the plastic waste that goes into the recycling bins also end up there in the end, with only about 10% currently being actually recycled (mostly it's PET that gets recycled, AFAIK).

edit: My 10% figure is some years old; plastic numbers are actually much better now! These days it's about 35%. For glass, paper and metal the same figures are all around 80% though so plastic still has a long way to go.

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