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?
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.