Understanding colloidal FeSx formation from iron phosphate precipitation sludge for optimal phosphorus recovery

Abstract

The use of sulfide to form iron sulfide precipitates is an attractive option for separation and recovery of phosphorus and ferric iron from ferric phosphate sludge generated in wastewater treatment. The key factors affecting the simultaneous generation and separation of iron sulfide precipitates and phosphate solution from ferric phosphate sludge have so far not been thoroughly investigated. This study therefore focuses on the recovery of phosphorus from synthetic sludge by controlled sulfide addition under different operating conditions. The factors that affect the phosphorus recovery, as well as the optimal process conditions to achieve an effective solid-liquid separation, were investigat..