Advancing phosphorus recovery from secondary resources through speciation, process chemistry, and product valorisation
Year: 2026
Type: article
Abstract: Phosphorus (P) recovery from secondary resources is increasingly important for reducing dependence on phosphate rock and closing material cycles. However, the diversity of P-bearing wastes prevents a universally effective recovery route. This review critically evaluates P recovery from industrial and metallurgical residues, wastewater, agricultural wastes, and emerging battery and lithium-processing residues by linking P speciation and mineralogy with process chemistry, product formation, and process viability. Evidence shows that P concentration alone is insufficient to determine recovery potential. Instead, calcium phosphate, iron phosphate, and aluminium phosphate associations govern dissolution, impurity co-extraction, and achievable products. Selective leaching followed by controlled precipitation is the most established pathway for solid P-rich residues, although reagent consumption, impurity dissolution, and precipitation control remain key limitations. Adsorption and crystallization are more applicable to dilute aqueous streams, but high P removal does not necessarily yield recoverable products. Thermodynamic analysis highlights ion activity, complexation, supersaturation, and metastable phases as critical determinants of product selectivity. Life-cycle and techno-economic evidence further shows that maximum P recovery does not necessarily maximize sustainability or profitability. The findings support feedstock-specific, product-driven strategies in which P speciation guides process chemistry and target product quality determines separation intensity.
Authors: Mojtaba Ajorloo, Tim Evans, Vladimir Strezov
Institution: Macquarie University
Language: English
Subfield: Waste Management and Disposal
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $5,270
OpenAlex ID: W7221663560