The increasing demand for crop production has led to a significant need for fertilizers, resulting in uncertainty in the supply of phosphorus-bearing macronutrients due to the depletion of phosphorus mineral reserves. Consequently, alternative sources of macronutrients such as phosphorus (P) or iron (Fe) are being explored. Nutrient-rich wastewater has emerged as a potential source for phosphorus recovery, with phosphorus precipitation being a promising method for recovering phosphorus from high-concentration wastewater. This process involves the crystallization of phosphorus in the form of PO4-P minerals, including well-known minerals such as struvite or vivianite, the latter being highly valuable and commanding the highest market price among P-containing minerals and products. The project aims to evaluate the impact of apparatus and process parameters on the kinetics of precipitation crystallization of vivianite in the recovery of phosphorus and iron from wastewater. The project comprises five main tasks: 1. WP1: Biological reduction of iron (Fe3+ to Fe2+), assessing the efficiency of the process using pure iron bacterial cultures and cultures cultured from excess sludge of municipal wastewater treatment plants (WWTP). 2. WP2: Recovery of phosphorus in the form of vivianite in the crystallization process, focusing on the influence of selected process factors on the kinetics of the crystallization process and the properties of crystallized vivianite. 3. WP3: Crystallization of vivianite using biological iron reduction effluent, evaluating the effect of the substrate subjected to biological iron reduction and the operational parameters of the biological iron reduction process on the crystallization process of vivianite. 4. WP4: Operation of an integrated system on real wastewater, evaluating the influence of real wastewater on the kinetics of biological iron reduction and vivianite crystallization processes. 5. WP5: Modeling of the vivianite crystallization process, involving the preparation of a mathematical model to characterize the vivianite crystallization process. This project is aligned with PG's priority research areas. The results of the project will be published in international journals and presented at international scientific conferences.