About the Bioset Process


One of the most important features of the Bioset process is that it consistently and reliably produces Class AA EQ biosolids from start-up to shut-down. Biosolids that remain in the reactor on shut down achieve Class AA EQ status in the reactor and are discharged as such upon start-up. Unlike competing Class A processes there are no operating scenarios, including start-up and shut down, where the Bioset process does not produce Class A biosolids.


General Housekeeping

The Bioset process is a clean system to operate as it is totally enclosed from start to finish. Being totally enclosed prevents dust and odors from escaping at the inlet, prevents biosolids from spilling during the process, and allows point source odor capture at the discharge.


No Supplemental Heat

All of the heat to operate the Bioset process is achieved via chemical addition. No expensive and maintenance intensive supplemental heat sources are required.


Long Term Stability

Unlike other alkaline stabilization processes that utilize supplemental heat to reduce lime dosages and subsequently lose the high pH shortly after processing, the Bioset process maintains Class AA EQ status months after processing.



The Bioset process has few moving parts and therefore few maintenance requirements. The primary component that requires maintenance is the Schwing Bioset piston pump. Since the Bioset process operates at less than 10% of the pumps rated operating pressure, the wear rates are nominal.


Reduced Operating Costs Through PFRP Approval 

The Bioset process has been approved as a PFRP process as the ammonia that is generated through lime addition is entrained with the biosolids inside the reactor and kills the pathogens. The PFRP approval allows the Bioset process to operate at 55C with a residence time of 40 minutes (versus 70C for 30 minutes). The most significant impact of this approval is the approximately 35% reduction in operating costs.