The pyrolysis process that the article refers to can turn organic material into biochar which is essentially charcoal. Organic material being anything that has carbon in it which does include sewage and critically plastics. There are studies about using biochar as reusable microplastic adsorption material but I’m not really qualified to draw any conclusions

I saw some tech a while ago referred that used hydrothermal carbonization which from what I can tell is a kind of “wet” pyrolysis. There was a company with a working demo system for sewage treatment which seemed promising, but I haven’t heard any new developments since I heard about them a few years ago. I don’t know if it’s just all up in regulatory processes or if it fizzled out.