Electrochemical phosphorus removal and recovery

Abstract

Phosphorus removal and recovery from waste streams is essential for closing the loop of phosphorus. In this thesis, we propose an innovative membrane-free electrochemical system, which can potentially achieve the removal and recovery of phosphorus from wastewaters in the form of recoverable calcium phosphate. We studied the fundamentals, efficiency, and energy consumption of electrochemical phosphorus removal and recovery in both synthetic solutions and real wastewaters. We showed electrochemically induced calcium phosphate precipitation depends on the local pH. We demonstrated the feasibility of electrochemical phosphorus recovery for both orthophosphate and no-orthophosphates. We concluded that a low current density and high phosphorus concentration enables energy-efficient phosphorus recovery. To our knowledge, this is the first systematic study focusing on electrochemical phosphorus removal and recovery. The insights we have gained from this thesis present therefore a significant step towards the potential application of this new technique.