Full-Scale Testing of the WASSTRIP™ Process

The first full-scale wastewater nutrient recovery installation in North America became operational in May, 2009 at the Clean Water Service's Durham Advanced Wastewater Treatment Plant in Tigard, Oregon. Recovering phosphorus from the dewatering side stream as struvite has a positive impact on plant operations, effluent quality, and recovers a limited resource. Significantly reducing the phosphorus recycle lowers the phosphorus loading on the plant, which stabilizes biological phosphorus reduces chemicals required to remove phosphorus, reduces both the dry tons of biosolids generated and the phosphorus content of the biosolids, and provides revenue from the sale of the struvite. Phosphorus is recovered as struvite prills which are a slow-release fertilizer. In the spring of 2011, the facility exceeded 1,000,000 pounds of struvite recovered for beneficial reuse. To increase struvite production by approximately 50% and to decrease struvite potential in the digestion system, the WASSTRIP™ process was implemented full-scale in summer 2011