Recalcitrant COD reduction to < 30mg/L in pharmaceutical wastewater

Screening various AOP's (advanced oxidation process) and other BAT's (best available technologies) to reduce the COD in the wastewater (200 - 300 gpm average to peak) from 100 mg/L to < 30 mg/L. The treatment train includes activated sludge treatment followed by an MBR. Looking at the following options:

  1. Ozone/Perozone
  2. UV Peroxide
  3. Activated Carbon
  4. Resins
  5. RO
  6. Ultrasonic
  7. AOP followed by a fluidized bed reactor (FBR)
  8. Wet Air Oxidation

I want to tap into your knowledge base to see if there are any other methods that are worth screening or experience someone has had with similar (pharmaceutical) wastewater and COD removal to very low levels.