Fosforun vivianit olarak geri kazanımının değerlendirilmesi

Phosphorus is essential for all living things and its recovery is a vital issue for the world. Existing practices have limitations in terms of efficiency and applicability and more economical and efficient phosphate recovery techniques are needed. If iron and phosphate are present and relatively less sulphide concentrations are present, vivianite an iron phosphate mineral, is formed in anaerobic conditions. Vivianite is a valuable mineral used in some industrial facilities and agricultural activities. Therefore, recovery of phosphorus from wastewater based on vivianite formation not only contributes to the sustainable use of phosphorus, but also provides potential economic opportunities. In this study, it was aimed to determine the recovery potential of phosphorus as vivianite and to evaluate the effects of operational conditions on phosphorus recovery. For this purpose, lab-scale semi-batch completely mixed crystallizer reactor (CSTR) was first used. After then, a lab-scale fluidized bed reactor (FBR) was operated based on the results obtained from the CSTR. Sodium phosphate solution and iron chloride solution was used as a phosphorus containing synthetic wastewater and as an iron source, respectively. In CSTR studies, the effects of pH, Fe:P ratio, Fe feeding rate, and P concentration for vivianite crystallization were investigated. In FB studies, the effect of seed material, P concentration, and recycle ratio was examined. As a result of all experimental studies, vivianite formation was observed in both reactors and confirmed by SEM, XRD, SEM EDS analyzes. P removal efficiencies of up to 50-69% has been achieved by vivianite crystallization. No precipitation was observed when the phosphorus concentration fell below 50 mg/L. Therefore, it was determined that wastewater with a high phosphorus concentration is more suitable for vivianite crystallization.