Organic Removal From Baker Yeast Manufacturing

We are working on a zero liquid discharge unit, the plant manufacture baker yeast from sugarcane molasses.

Input BOD/COD are in the range of  30000/60000 mg/l.

After treatment of UASB, this gets reduced by 60-70%. A huge volume of sludge is generated during this process, which is later removed in a settler.

Is there any way to reduce this sludge production? 

We use the biological system for reduction of BOD/COD. Final treated effluent is having  BOD/COD level of 6000-14000 mg/l.

Which other good methods can be applied to reduce the level of BOD/COD?