the recovery of phosphorus from acidic ultra-high phosphorous wastewater by the struvite crystallization

Phosphorus recovery from industrial wastewater has attracted considerable interest. In this study, struvite crystallization method has been used for treatment of high phosphorus wastewater. The new combination agents of Mg₅(CO₃)₄(OH)₂·4H₂O and NH₄Cl were used as the precipitant. The effects of initial pH, n(Mg):n(P), n(N):n(P), and reaction time on the removal of total phosphorus (TP) in wastewater were investigated. The results showed that under the condition of initial pH = 4, Mg:N:P = 1.2:1.1:1, reaction time for 30 min, and static storage for 20 min, the residual amount of TP in wastewater was 2.98 mg /L, and the removal rate of TP reached 99.99%. The mass fraction of P₂O₅ in the generated sediment reached 25.22%, equivalent to high grade phosphate ore and slow-release fertilizer, so as to realize the recycling and utilization of phosphorus in ultra-high phosphorous wastewater. This work will have practical application potential in treatment of high phosphorus wastewater and environmental management.