Conventional Treatment

Initial treatment removes over 90% of most incoming pollutants and provides a high-quality effluent for subsequent advanced waste treatment polishing steps.




Chemical Advanced Treatment

UOSA uses the high-lime process to reduce phosphorus to below 0.10 mg/L. This process also serves as a barrier to viruses, captures organics leaving secondary treatment, and precipitates heavy metals.


 

Physical Advanced Treatment

The UOSA permit requires TSS below 1 mg/L and COD below 10 mg/L. To meet these stringent levels, multimedia depth filtration and activated carbon are used.



UOSA has two process trains, one with pressure filtration and one with gravity. The gravity system (L/2) is as follows:

The pressure process train is similar:

Activated carbon is regenerated onsite with a multi-hearth furnace

Disinfection



The final barrier to pathogens is a chlorination and dechlorination process. UOSA uses sodium hypochlorite and sodium bisulfite, and is designed to use these chemicals for breakpoint chlorination as necessary.

 

Digestion and Sludge Handling



Primary sludge and waste activated sludge are screened, digested, blended, dewatered, and ultimately dried to produce fertilizer pellets.