It seems counter-intuitive, but the cleaner the waste water the harder it is to treat. When a coagulant is added to nearly clear waste water it will often form a very tiny floc known as a Pin Floc. In waste water treatment Pin Floc is to be avoided. Pin Floc tends to not settle and can cause filter problems. To produce a more robust floc that will settle and can be separated and filtered out, a Body Feed is often added. A common Body Feed for industrial waste water treatment is Bentonite Clay. Bentonite Clay is inexpensive and can be purchased in 50 lb bags or in 2,000 lb totes.
To see if adding a Body Feed is the answer to your settling and separation issues, jar testing is recommended. Start with 500 ml of waste water and add Bentonite clay along with the coagulant and flocculent already in use. Add the clay in ½ gram doses. Give the clay time to unwind and begin to work by waiting at least one full minute between doses. Keep the mixer on high and add until you see a robust floc that will settle easily when the mixer is turned off.
A Body Feed such as Bentonite Clay is an inexpensive way to improve settling and filtering of your treated waste water.