Startup of the first US NuReSys Phosphorus Sequestration Facility

Pima County recently commission the first Schwing NuReSys phosphorus sequestration system in North America at the Tres Rios Water Reclamation Facility (WRF). The process was installed to minimize ferric chloride use for struvite control, improve dewaterability, and further enhance biological phosphorus removal by sequestering a minimum of 85% of the recycle phosphate released during anaerobic digestion. This phosphorus sequestration system was installed between the digesters and dewatering, downstream of the screen press, treating digested sludge. While provision for future product harvesting were included the generated struvite remains in the sludge and is l and applied with the biosolids. The system has been fully commissioned and is now operation. While plant staff is still adapting to operating the NuReSys, early results point towards a successful implementation as the anticipated savings from reduced ferric use and cake hauling trend in the right direction. Even with the switch to a different, more expensive polymer the net saving still support a return on investment in less than 10 years in addition to eliminating nuisance issues associated with struvite. Plant staff are actively testing polymers to find a more cost effective product.