Recovered phosphorus (struvite and other recovered phosphates from biological wastewater and digester streams) instead of fertilizer made from cadmium-bearing phosphate rock

Replaces (partial): rock-derived P fertilizer share; chemical P precipitation at treatment plants · Scope: municipal and food-industry wastewater · Evidence: medium–high

The chemical problem#

• Mineral P fertilizer comes from phosphate rock, a finite resource concentrated in a few countries (Morocco/Western Sahara holds most reserves).
• Sedimentary rock contains cadmium; the EU limits Cd in fertilizer to 60 mg/kg P₂O₅ under the Fertilising Products Regulation.
• Wastewater plants remove P to protect rivers — often by dosing iron or aluminium salts, which binds the P into a sludge plants cannot use easily.

Product overview#

1. Enhanced biological phosphorus removal (EBPR) — polyphosphate-accumulating bacteria take up P in the activated-sludge process, replacing metal-salt dosing.
2. Struvite recovery — in the digester, the P is released again; adding magnesium to the digester liquor precipitates struvite (MgNH₄PO₄·6H₂O) as clean crystals.
3. Use as fertilizer — granular struvite is a slow-release N-P-Mg fertilizer with very low heavy-metal content.
4. A side benefit for the plant: controlled struvite precipitation prevents scale that blocks pipes and pumps.

Active ingredient / Composition#

• Struvite: ~5–6 % N, ~28 % P₂O₅ (in pure form ~29 %), ~16 % MgO.
• Cd and other metals usually far below rock-derived fertilizers.

Key facts#

Advantages#

• Low cadmium — a clean P source where soil Cd is a concern.
• Domestic P supply for import-dependent countries.
• Cuts metal-salt purchases at the treatment plant and reduces pipe scaling.
• Slow release suits perennial and horticultural crops and lowers P run-off.

Mode of action#

• EBPR bacteria store P as polyphosphate under alternating anaerobic/aerobic conditions → P is concentrated in biomass instead of precipitated with Fe/Al.
• In anaerobic digestion the P is released into the liquor; controlled pH and Mg addition crystallize struvite.
• In soil, struvite dissolves near roots as they release organic acids, supplying P, N and Mg.

Application#

Limitations#

• Recovers only part of the P in wastewater; the rest stays in sludge (see WC03) unless ash-based recovery is added.
• Slower P release in alkaline soils; combine with soluble P for young crops.
• Needs a larger plant with digestion — not viable for small works.
• Public acceptance and fertilizer approval of “sewage-derived” products differ between countries.

Evidence of displacement — D1: works, adoption not proven#

Verified figures (the number is in the quoted sentence and the sentence is on the source page):

• displacement — Struvite production in the European Union in 2020 accounted for 0.5% of the total phosphorus theoretically contained in EU wastewater or 0.06-0.07% of the EU phosphorus imported for fertilizer use in 2017. (EU, 2017-2020; peer-reviewed: exa.ai)
• displacement — Struvite recovery from wastewater currently accounts for approximately 0.5% of fertilizer phosphorus imports to the EU. (EU, 2020; weak: susfert.eu)
• displacement — Struvite recovery from wastewater currently covers only 0.1% of EU agriculture’s phosphorus demand. (EU, 2025; weak: fer-play.eu)
• performance — Struvite and other bio-based fertilizers showed mean mineral replacement values of 80–125% compared to triple superphosphate in field experiments. (Europe, 2025; peer-reviewed: exa.ai)

Suppliers — real products and services (from the vendor index)#

Honest finding: no company in this index shows struvite or another recovered-phosphate fertilizer product on its own card. The closest cards describe general “nutrient recovery” inside biogas or wastewater systems — e.g. WEC Water (resource beneficiation incl. nutrients and biosolids), SGTech (livestock-waste nutrient recovery) and Spans Envirotech — but none names a recovered-P fertilizer, so none is cited as a supplier.

Update 2026-10-02: the new USA & Canada dataset supplies this product — rows marked NA below. For Africa/ME, LatAm and Asia the regional gap noted above still stands.

Companies below are active vendors in the vendor index whose own card (profile / official website) shows this product or service — matched 2026-10-05 by keyword and checked by hand against the card text. Being listed is not an endorsement; open each card for evidence, contacts and status.

Update 2026-10-05: the new Europe dataset supplies this product — rows marked Europe below. For the other regions the gap noted above still stands unless a row says otherwise.

Government funding signals#

Scanned 2026-10-01 (OpenAIRE + NSF); candidates reviewed by hand.

Signal: Moderate. A steady line of public projects, from EU FP7 (230788, struvite precipitation from wastes) to commercialization: NSF I-Corps 2241633 “Struvite Recovery for Organic Food Production” (2022), FCT SFRH/BD/84116/2012 “biological struvite production”, UKRI-EPSRC 2931885 (struvite precipitation and nutrient recovery modelling, 2024) and Academy of Finland 323655 (nutrient recovery from industrial wastewater, €345 k).

Scientific evidence#

• Cordell D, Drangert JO, White S (2009). The story of phosphorus: global food security and food for thought. Global Environmental Change 19: 292–305.
• Talboys PJ, Heppell J, Roose T, et al. (2016). Struvite: a slow-release fertiliser for sustainable phosphorus management? Plant and Soil 401: 109–123.
• Huygens D, Saveyn HGM (2018). Agronomic efficiency of selected phosphorus fertilisers derived from secondary raw materials for European agriculture. A meta-analysis. Agronomy for Sustainable Development 38: 52.
• Roberts TL (2014). Cadmium and phosphorous fertilizers: the issues and the science. Procedia Engineering 83: 52–59.

Bioeconomy value#

Biological P removal plus struvite recovery turns a water-protection cost into a clean fertilizer. For phosphate-importing countries it is a small but strategic domestic P source. In this catalogue it is a supplier gap, not a demand gap.

Cross-links: W01 biological treatment; WC03 sewage and faecal sludge; NU03 organic fertilizers.