Hi at Aerofloat (Australia), ...

Hi at Aerofloat (Australia), we've completed a few projects for plastic recycling companies. Using our patented Aeration and Patented AeroDAF, we recycle the water for the plastic washing process.

A typical process is Sweco Screen > AeroMBBR > AeroDAF > Return to wash plant. This maintains an odourless low TSS wash water, improving the quality of the finished plastic and reducing maintenance on pellet machines. 

For Zero BOD, you would require chemical addition to the DAF for improved clarification of MBBR biosolids and fine solids from the washing process, + possible filtration off DAF effluent Sand filter or UF perhaps. 

Cheers
Michael 
www.aerofloat.com.au