Our waterways are becoming more and more polluted due to PFAS, plastics, medicines, drugs, and new chemicals made by companies that just hand over the responsibility of cleaning to plants paid for by public moneys. Detecting the different chemicals and filtering them out if getting harder and harder. Could the simple solution of heating up past a point where even PFAS/forever chemicals decomposes (400C for PFAS, 500C to be more sure about other stuff) be alright?
This would be carcinogenic beyond imagination
Please explain.
Because you’re essentially cooking a cocktail of complex chemicals, many of which were never designed to be heated, and the result is often airborne toxins and volatile organic compounds (VOCs) that are far worse than drinking trace amounts of the original chemicals.the chemicals dont vanish or turn into pure air when vaporized. they degrade into other more harmful chemicals. which are carcinogenic and more toxic.
Can the degraded chemicals withstand sustained exposure to 500C?
The chemicals don’t just disappear, whatever they’ve degraded into will still remain.
Yes, but will they all be harmful?
they can get even worse than previous forms, so yes.
Got an example?
Molten Salt Nuclear Reactors (like the one China’s making with thorium) operate at something like 700* C to generate electricity. With the waste heat, we could desalinate water. Instead of Yucca Mountain as a nuclear waste repository, it becomes Yucca Mountain Molten Salt Nuclear Reactor and brackish groundwater distillation for Las Vegas.
This, I like. The water would be radioactive though, wouldn’t it? I wonder if “exchanging” the unknown toxins for radioactivity in the dispelled water would be better or worse. But, it could maybe help decompose some of the toxic chemicals during in the process.
No. Radioactivity isn’t like a disease. Specific particles are radioactive. If you remove it prevent contamination form the first place, there is no reason the water would become radioactive. Heat is just heat.
That made no sense at all. Do you think toxic water is 100 toxins or that when somebody is sick they become one big walking disease?
And “water can’t become irradiated” is a great take. So radioactive radiation has no effect on water whatsoever? “High energy particles don’t exist and they can’t hurt you🧠”
When someone more knowledgeable than you is giving you good answers to your questions you should maybe show a bit more respect
Raising water temperature from 10 to 500 degrees requires about 500 calories/mm3. That’s 2 MJ/litre, meaning if you want to heat 1 liter/second you need 2 MW with perfect insulation, so a power plant of say 10 MW.
A post industrial world citizen could probably get by on 200 l/day (US averages about 300/day). That needs 2 kW/person/day.
Total global energy production is about 630 EJ which averages out at about 12 TW.
Meaning if the whole global energy production went to treat water in that way, we have enough clean water for about 6 million people.
Yes, with our current energy output it would not be possible, but I’m asking about whether even theoretically it could be an easier way to clean water. Maybe in 10, 20, 50 or 100 years it’s a method worth pursuing.
This is simple math. We would need to increase our energy production by 1000 times to just treat water, maybe only 250 times if we used more efficient systems than simply heating it and letting the heat dissipate. If we doubled our energy production every year, it would still take a decade to do it (8 years if we were aiming at 250 times). That isn’t a realistic amount for a civilization at our tech level.
You say 1000, another poster says 11, and yet another gives another number I can’t remember.
If I’m reading the graph right on page 20 of Homo Sapiens’ Energy Dependence and Use Throughout Human History and Evolution, in 1820 we needed about 20 EJ. That’s a 31 fold increase to ~530 EJ in 2010 (190 years). Looking at the chart, you can see that the rate of increase has sped up, not slowed down. In 1960 it was ~120 EJ making it a 4x increase in years.
It might take time, but it’s not impossible. And unless a great calamity happens upon us, we will not stay at our current tech level for another 200 years.
I understand the pessimism, but my question wasn’t about “is this possible within our lifetimes” or “how much energy would this need” but “Could wastewater plants simply heat up water past 500C to decompose all chemicals and output clean water?”. I just want to know if with our understanding the water will be clean after going through a procedure where it’s heated past 500C. That could be once or multiple times, it could involve adding a filter, removing deposited waste material, etc.
The part you’re studiously ignoring is plenty of people saying yes, you could do this, but that it’s wildly inefficient. You could also power a bike by getting the biggest rock you could throw, tying a rope to it, applying the brakes on your bike, throwing the rock, releasing the brakes, and then pulling on the rope until you’ve collected your rock, and repeating until you’ve reached your destination. This will always work. But as long as your bike is in earthlike conditions, there will always be easier ways to do it. This is also the case for your idea.
You’re ignoring that I’m responding to the messages that say it’s wildly inefficient by saying things can change. Nowhere am I debating it’s not inefficient. You’re arguing with a strawman you built.
Yes; this is something that has been studied. However as other commenters have said it requires a lot of energy, and is better suited for processing smaller quantities of water with a high level of PFAS contamination than massive quantities of water with an extremely low level of PFAS. It’s also not a standalone solution, as plenty of harmful chemicals survive heating past 400/500C (heavy metals like cadmium, lead, and mercury do not break down at any temperature).
In a practical sense, making lead hot won’t break it down. But I wonder if there is any temperature where lead would stop being lead and continue to not be lead after the results cool down again?
Alchemy! Now this is the out-of-the-box thinking that I like!
In all seriousness, lead is lead because it’s made of lead atoms. It can’t not be lead. (The reference to alchemy was because before we knew about atoms, many alchemists tried their hand at turning low-value metals like lead into high-value metals like gold).
To answer your question in a silly but scientifically accurate way, there is a temperature to which lead can be heated to become something else, but these are nuclear fusion temperatures, like you get in the Sun.
Magnetic fields should be able to extract lead.
How would that work? You gonna ionise the lead? 🤔
Why would that be necessary? Does led not react to magnetic fields?
Thank you for the only response that actually answers the main question and linking to a scientific paper. Much appreciated.
Regarding harmful chemicals that do not decompose beyond 500C, could it be more likely that the number of such chemicals/materials (known and unknown) is much lower than the number of chemicals/materials at the temperatures used for current clarification processes?
As you can see, these communities are an absolute fucking joke, and only like 15% tops of the comments are actually helpful or backed up by reputable sources.
Yeah, a lot of responses forget the name of the community and go straight into debate mode about something that isn’t even asked. I don’t think it’s a surprise that people are enjoying AI so much more than engaging with humans. AI will just give you an answer (be it wrong or not) without trying to one up you or prove that “you’re stupid, shut up”.
Yea but AI also makes shit up or gives answers from sarcastic Reddit comments without knowing it’s sarcastic. It’s all shit honestly.