Struvite from Wastewater and Side Streams– STRUVIKS

The aim of the project is to investigate the suitability of return sludge from a wastewater treatment process based on biological phosphorus removal (BioP) for nutrient recovery in the form of struvite. Struvite, or magnesium ammonium phosphate, is a slow-release phosphate compound suitable for use as a fertilizer, in which nutrients are available to plants in a slowly soluble form.

During the project, the struvite precipitation pilot equipment at the Huittinen Wastewater Treatment Plant will be further developed. Different virgin and side-stream-derived additives, such as magnesium, will be tested in the precipitation process, and alternative nutrient-rich fractions for nutrient recovery will be identified and, where possible, tested. In the earlier BioP-Rec and BioStruvi projects funded by the Finnish Ministry of the Environment, struvite was successfully precipitated from BioP sludge using the pilot equipment.

The objective of the STRUVIKS project is to find solutions to the identified challenges. The project will further investigate methods to accelerate sludge aging and improve the growth and purity of struvite crystals. One of the project’s goals is also to map different nutrient-rich fractions and assess the potential of their macronutrients (such as P, N, K, Ca, and S) for recovery in the form of struvite.

In addition, the project will examine struvite precipitation from a techno-economic perspective and evaluate market interest in struvite in Finland among both fertilizer manufacturers and farmers. In the long term, the project aims to increase awareness of nutrient recycling from municipal wastewater treatment plants into a form readily usable by plants and to strengthen fertilizer security of supply by promoting awareness of domestic recycled nutrients.

The project implementation period is from 1 September 2025 to 31 December 2026.

The project has received funding from the AHTI Programme of the Ministry of the Environment of Finland.

 

Contact information:

Julia Pihlavisto-Hakala

julia.pihlavisto-hakala@prizz.fi

050-434 2163