Pilot Plant Tests on the Novel Process for Phosphorus Recovery from Municipal Wastewater

Abstract

In enhanced biological phosphorus removal (EBPR) processes, activated sludge microorganisms accumulate large quantities of polyphosphate (polyP) intracellularly. We previously discovered that nearly all of the polyP could be released from activated sludge simply by heating it at 70°C for about 1 h. The addition of CaCl₂ precipitated the released polyP at room temperature without pH adjustment. In the present study, we examined the feasibility of this simple technique for recovering phosphorus (P) from municipal wastewater at pilot plant scale. The pilot plant tests demonstrated an average P recovery of about 40% over the one-year operating period.