WWTPs have not proven successful at removing metformin or its metabolite. https://www.sciencedirect.com/science/article/pii/S2213343722009794 https://www.scien

WWTPs have not proven successful at removing metformin or its metabolite. https://www.sciencedirect.com/science/article/pii/S2213343722009794 https://www.sciencedirect.com/science/article/pii/S221334372... Granted, this particular chemical partitions into water, not the solids, so it isn't the best example here.