Recycling, Repurposing Waste Technologies

That article is pretty poorly written, in the first few sentences are wrong compared to the rest of the article. It seems the road isn't made out of steel, but the slag.

Broadly, "ore" is a mineral rock with a high content of metal, which is separated in a furnace into two parts: the metal and the slag. Most iron ore comes from Precambrian Banded Iron Formations, oceanic sandstone, which these days is mostly put in a reducing blast furnace to separate pig iron out while the rocky slag (basically artificial lava) oozes out.

So what they're doing there is using slag from iron production as an input to roadmaking as a substrate, instead of stone aggregate basically.

Thinking about the numbers,
According to the USGS per wikipedia, there's like ~1800 million tonnes (metric) of steel produced a year and that produces another 60% weight in slag I guess, so like 1080 million tonnes. I guess per the World Asphalt Association says there's a world consumption of 123 million tonnes/year of asphalt per year.

Well, at the end of the day slag and asphalt are very cheap per lb and used in enormous quantities, so shipping costs (whether on a dollar-cost or emissions-cost basis) are going to drive how much uptake this study has.

Plus, uh, the heavy metal content of the slag, which is usually the biggest concern for mining tailings, that leaching into the groundwater. Maybe a little scary to use this stuff in roads literally directly over the top of your water mains, but hopefully they don't use the poisonous stuff for this job.
 

View: https://www.youtube.com/watch?v=p6CF-umWLZg

From the video: There's a rich, carbon-neutral resource that we could tap into: Turning human waste into energy instead of flushing it down the toilet. It could be used as a coal alternative, carbon sequestration, strengthening concrete and more. There's an old technology, hydrothermal carbonization, that's starting to make a splash and might change the way you think about number 2.
 
That article mostly talks about nitrogen, which is kind of a weird one because synthnetically we-as-a-species have actually colonized the same niche as the nitrogen-fixing bacteria in an ecological sense: turning dipolar nitrogen gas into ammonia, where the N has lower bond enthalpies and can actually be accessed by the plants.

So the war is affecting that one just because it consumes energy (natural gas) to run the factories that run the air into plant food. So that's more of the same problem that Germany has been pushing its economy to be more and more reliant on Russian gas over the last two decades.

Meanwhile the fertilizer that Russia actually exports is potash, Potassium Chloride. And that's digging up ancient seabeds to release potassium that was sequestered millions of years ago.

I dunno. I guess the thing is that probably the best way to go about reclaiming essential elements from human waste is to go large scale for efficiency and just add reclamation capacity to city waste treatment plants, rather than trying to implement things piecemeal in like, individual toilets.
 
The real question is, how fast can bacteria use that enzyme to break down PET in the environment? The article's interested in using it in recycling plants; I'm more interested in what would happen if a lot of bacteria got the genes to produce the enzyme.
 
Citrakayah said:
The real question is, how fast can bacteria use that enzyme to break down PET in the environment? The article's interested in using it in recycling plants; I'm more interested in what would happen if a lot of bacteria got the genes to produce the enzyme.
Click to expand...
Click to shrink...
The researchers were using plastic flakes in a 70°C reactor, which is a lot different than solid pieces of plastic sitting in cold seawater. Some materials - like wood - are just physically hard to break down even if you have the enzymes to do it. I guess it's worth asking how much a tiny rate of plastic degradation adds up to on a global scale though. I imagine a lot more is degraded by solar radiation or buried under sediments, but all natural removal routes put together aren't nearly enough to deal with the sheer amount of plastic pollution.
 
www.sciencedaily.com

Superworms capable of munching through plastic waste

Researchers have found a species of worm with an appetite for polystyrene could be the key to plastic recycling on a mass scale.
www.sciencedaily.com
They've found worms that can digest polystyrene due to gut bacteria, and anticipate that the, er, byproducts to make new plastics.

Not clear if they intend for the worms themselves to be used for recycling or to isolate the gut bacteria making the enzyme.
 
Traveller76 said:
www.thebetterindia.com

Father-Son’s Tech Turns Steel Waste into 99% Pure Metal Without Electricity

Can waste from industry be channelised to create wealth instead of harming the environment? These innovators are using unique ideas to find out.
www.thebetterindia.com www.thebetterindia.com
Click to expand...
Click to shrink...

"Sandeep and his father's technology is like the latter — a manual process that they say needs 'focus and precise movements of hands'." (Bold mine)
What?

"Sandeep says the technology is based on pyrometallurgy, which means using a high temperature to extract a pure form of metal."
Is there any other way to refine iron?

"The source of heat in these reactions comes from the combustion process, and the temperatures are high enough to melt the material in about five minutes."
Is there a modern process that does not involve burning fuel to generate the required energy?

I can't make head or tail of what's supposed to be novel in their process.
 
www.bbc.com

Asbestos is a global waste problem - here's how we might get rid of it

Millions of tonnes of asbestos are being removed from buildings around the world – can this dangerous mineral be disposed of permanently? Or even be put to good use?
www.bbc.com www.bbc.com

From the Article: The US Environmental Protection Agency estimates that more than 30 million tonnes of asbestos were used in the US between 1990 and 1980. In 1989 a partial ban came into place, but the US has continued to import asbestos up until this year, so the figures will be even higher now.
 
scitechdaily.com

Extracting Pure Gold: Turning Electronic Waste Into Treasure

A fibrous adsorbent selectively recovers high-purity gold from waste. Dramatically reduces the cost and time of the recovery process and enables material to be mass-produced and repeatedly recycled. Korea relies on imports for most of its metal resources, and in recent years, due to resource depl
scitechdaily.com

From the Article: In this context, a team led by Dr. Jae-Woo Choi of the Water Resource Cycle Research Center at the Korea Institute of Science and Technology (KIST) announced that they have developed a technology that can selectively recover high-purity gold from electrical and electronic waste containing various metals using textile materials.
 
www.theguardian.com

‘They lied’: plastics producers deceived public about recycling, report reveals

Companies knew for decades recycling was not viable but promoted it regardless, Center for Climate Integrity study finds
www.theguardian.com www.theguardian.com

Something to keep in mind is that recycling tech has been heavily pushed by plastic producers for the last three decades while they knew it would not work economically or technologically. Hoping we can 'innovate' our way out of pollution is what the companies making the pollution want. So one should always take any story of new tech with a grain of salt.
 
Yeah, PBS has been posting videos on YouTube criticizing Green Capitalism for basically all of April, with this being the latest addition. Surprisingly, they've even managed to get away with all but outright saying that capitalism needs to go to fix the problem.
 
Let's be real, technology has to fix the problem because we're not giving up on technology.

Recycling will always be part of the solution, too. If it's not good enough, yet, then it will need to be improved.

Like, seriously, what's the proposed alternative? Bigger landfills?
 
armorfiend said:
Let's be real, technology has to fix the problem because we're not giving up on technology.

Recycling will always be part of the solution, too. If it's not good enough, yet, then it will need to be improved.

Like, seriously, what's the proposed alternative? Bigger landfills?
Click to expand...
Click to shrink...

The solution to disposable plastic bottles being horrible to recycle is not to invent a new technology that makes them less horrible to recycle but to not use disposable plastic bottles. The solution to recycling being hard to do when you have 30,000,000,000 different kinds of plastic is to limit the kind of plastic used to those easier to recycle and separate. Working around the limitations that exist today is the solution instead of saying technology will fix it and just expecting the exact right technology to happen in the exact right time frame.
 
armorfiend said:
Let's be real, technology has to fix the problem because we're not giving up on technology.

Recycling will always be part of the solution, too. If it's not good enough, yet, then it will need to be improved.

Like, seriously, what's the proposed alternative? Bigger landfills?
Click to expand...
Click to shrink...
The proposed solution isn't abandoning technology, or bigger landfills, but changing our approach to the problem and forcing industry to actually address the problems. We can't capitalism our way out of a problem stemming from capitalism's incentives, but doing things like banning single-use plastics, implementing better and more thought out regulations without lobbyist input, and accepting that we can't just keep growing consumption will go a long ways towards making human habitation of Earth sustainable.
 
You must login or register to reply here.
Back
Top