Issues in Coagulation Process

I am currently working on a waste water treatment project involving biological pre-treatment of dissolved air systems.

The residual water is waste product of a coffee company, with pH of 4.5, fats and oils range are between 40 and 50 ppm and total suspended solids of approximately 350.

The presence of tannins is apparently causing a short circuit in the coagulation and the flocculation process. Which treatment method would you suggest for treating this waste water?