Good question.  Of direct interest to me is a polyvinyl alcohol polymer sitting in domestic waste water (a by-product of certain household products normal usage).  Specifications allow for different dissolving temperatures, so it may still be a solid polymer and not fully dissolved when reaching waste water processing. Biodegradation specifications require up to 18 days in contact with a bacteria that is common in active sludge but not common in the environment or especially oceanic water - so if it is not retained for long enough in this environment, polymers may survive - undissolved and not biodegradable - into open water. What I am trying to get my head around is: Will it be typical for domestic waste water to be subjected to active sludge bacteria for a matter of hours, for a matter of days or for a matter of weeks?  What are the typical upper and lower contact times? I don't know the terminology well enough to tell you if that is about solid retention or hydraulic retention...do you need extra data?

Published October 27, 2020 11:50 by Nick Stene Dip DigM, Director and Digital Marketing Consultant