First, run some jar tests ...

First, run some jar tests with cationic floc agent (especially if the polymers you refer to are anionic), if no response, then try a jar test with anionic polymer to induce floc.  If you have a successful result in the jar tests, you will know how to remove by addition of complementary charge polymers, then you can use a  clarifier to remove the resulting floc prior to any treatment such as ultra-filtration.  It seems that whoever designed your wastewater process opted for the latest gadget before really doing any critical thinking about the process.