BioWin Modeling Comparisons of Municipal Wastewater Phosphorus Recovery between Brushite and Struvite

New technologies hold promise for advancing wastewater treatment by enhancing phosphorus (P) removal and recovery. The CalPrex precipitation reactor treats acidogenic digest with lime to precipitate brushite, recovering P in a form suitable for land application while reducing the buildup of nuisance struvite. To assess CalPrex performance in different scenarios, including its interaction with existing Ostara (struvite) reactor installations, we adapted a BioWin configuration of a municipal wastewater treatment plant hosting both a pilot-scale CalPrex reactor and a full-scale Ostara reactor. Our modeling work aimed to estimate the impact of reagent dosage on plantwide P recovery. When used alongside the Ostara process, CalPrex captured 36% of influent P, resulting in a 48% reduction in struvite precipitates in the anaerobic digester and a 12% decrease in the overall sludge production. As the sole P removal process, CalPrex was predicted to capture 41% of influent P, leading to a 33% decrease in anaerobic struvite precipitates and an 8% reduction in total sludge production compared with the current configuration with the Ostara reactor. This study represents the first attempt to model CalPrex interactions with other wastewater treatment technologies and can inform wastewater operators seeking to expand their P management systems.