In a world of ever-growing economy and global population the recovery and immobilization of nutrients and heavy metals from municipal, agricultural and industrial wastewater streams is of paramount importance for the conservation of limited natural resources and the prevention and remediation of environmental pollution.
One of our current projects in this research theme aims to elucidate the homogeneous and heterogeneous crystallization pathways of struvite (MgNH4PO4·6H2O) – a prime magnesium phosphate mineral that can be recovered from wastewaters. A clear advantage of struvite is that it can be used as slow-release fertilizer containing three major plant nutrients (N, P and Mg) in its crystalline structure. In the laboratory, we synthesize struvite crystals under a range of environmentally relevant conditions and follow all formation steps from the earliest nucleation stages to the final crystal by using a range of in situ imaging, spectroscopy and scattering techniques (e.g., LC-TEM, Raman spectroscopy, SAXS/WAXS). By providing a fundamental understanding of struvite formation pathways the outcomes of this research may guide the development of more efficient P and N recovery systems.