1% Ferric Sulphate or Ferric Chloride w/w, 5% lime solution w/w (50grm/ltr solution, 1.5% Bentonite solution (50gr/ltr solution), 1% Perlite body aid w/w.
Some are wary of Ferric Chloride due to it's corrosive nature and other wary of Ferric Sulphate due to it's sulphate increase in the exit filtrate.
Mix lime first with waste paint, then ferric chloride, then wait a few minutes for pH reactions to settle. Mix in Bentonite solution and then Perlite last. Mix well with low shear action.
Pump through a filter press and you'll get approximately 25% residual moisture in the collected solids with very clear exit filtrate. You'll get even better results if the solutions added are at around 35 to 40 Deg C. The cake (collected solids) will drop cleanly from the filter cloth and there'll be no incremental clogging or blinding of the filter cloth like you'll find in drum filters or belt filters.
With water based latex bound paint, there is no free lunch with regard to separating the solids from the liquid.
Stay away from drum filters and belt filters. The mess will drive you nuts and you'll end up going postal on fellow co-workers due to the enormous maintenance requirements.