Resin printing is wonderful. I love it – it’s fast and detailed compared to FDM printing. Also, the materials are getting better and better. However, compared to FDM printing is a really messy process. The resin frequently drops where you don’t want it to, and you have to wash the models in an IPA bath.
And here comes the problem – how should you safely dispose of a dirty IPA bath? The resin before it is cured is toxic, especially to aquatic life. The best way is to probably bring the bath to a facility for hazardous waste disposal. Nevertheless, the idea of recycling IPA is appealing so you see a lot of people on YouTube and Facebook trying to clean it and recycle it.
Here I bring my 2 cents on the topic. Note that what I present here is more of an idea or a proof-of-concept rather than a complete solution. Also, I am no chemist, so I cannot guarantee that the presented procedure actually yields safe waste. If you have some insight or ideas, please, let me know in the comments!