Sustainable Phosphorus Recovery from Wastewater: A Viability Assessment for the Circular Economy

Abstract

The current global utilization of phosphorus is reaching an unsustainable rate for a resource that is both non-renewable and irreplaceable as a primary nutrient for agricultural fertilizers. A significant portion of this phosphorus is lost via effluent from wastewater treatment plants (WWTP), not only posing the risk of toxic algal blooms in local watersheds but also wasting a valuable material. Recovering phosphorus from WWTP effluent is a concept gaining popularity as a Circular Economy (CE) framework, following the methodology of stopping single-use, linear waste streams and instead finding sustainable, economic reuse for discarded resources. This thesis is focused on conducting holistic technoeconomic analyses of three different recovery systems: struvite chemical precipitation, enhanced biological phosphorus removal (EBPR) via microorganisms, and algae-based EBPR. Modeling of these systems was conducted using the Activated Sludge Digestion Model (ASDM) software BioWin in the context of the Camden WWTP in New Jersey to evaluate the technical feasibility, economic viability, and environmental impact of implementation of these recovery processes. While the EBPR and algae focused recovery systems presented potential, the struvite precipitation method of phosphorus extraction proved to be the most effective system for the Camden WWTP based on simulated results from BioWin modeling and struvite valorization estimates from market analysis. Implementation of struvite recovery from wastewater can be efficiently incorporated into the current plant operations and presents tangible economic and environmental benefits through reuse of struvite as a slow-release fertilizer.