Project #5004

Demonstrating the CalPrex System

In Progress
Principal Investigator
Research Manager
Ms. Stephanie Fevig
Centrisys Corporation
Resource Recovery


More stringent nutrient regulations for both land application and the sale of biosolids are driving the industry to evaluate technologies that remove and recover phosphorus in a cost effective and sustainable manner. As a result, the Milwaukee Metropolitan Sewerage District, Madison Metropolitan Sewerage District, Metro Wastewater Reclamation District of Denver, and Massachusetts Water Resources Authority are collaborating with Centrisys/CNP (Kenosha, Wisconsin) to demonstrate the potential of CNP’s CalPrex phosphorus removal and recovery system. Results of the project will help water resource recovery facilities (WRRFs) evaluate and benchmark state-of-the-art alternatives for removing phosphorus from sludge going to digesters. The goal is for utilities to use phosphorus recovery technologies such as CalPrex to mitigate operations and maintenance issues related to struvite scaling in pipes and poor sludge dewaterability. Simultaneously, WRRFs implementing such technologies will better meet increasingly stringent regulations on phosphorus while recovering a valuable fertilizer.