Abstract
Minable phosphorus (P) reserves are being depleted and will need to be replaced by recovering P that currently is lost from the agricultural system, causing water-quality problems. The largest two flows of lost P are in agricultural runoff and erosion (∼46% of mined P globally) and animal wastes (∼40%). These flows are quite distinct. Runoff has a very high volumetric flow rate, but a low P concentration; animal wastes have low flow rates, but a high P concentration together with a high concentration of organic material. Recovering the lost P in animal wastes is technically and economically more tractable, and it is the focus for this review of promising P-capture technologies. P capture requires that organic P be transformed into inorganic P (phosphate). For high-strength animal wastes, P release can be accomplished in tandem with anaerobic treatment that converts the energy value in the organic matter to CH4, H2, or electricity. Once present as phosphate, the P can be captured in a reusable form by four approaches. Most well developed is precipitation as magnesium or calcium solids. Less developed, but promising are adsorption to iron-based adsorbents, ion exchange to phosphate-selective solids, and uptake by photosynthetic microorganisms or P-selective proteins.
Original language | English (US) |
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Pages (from-to) | 846-853 |
Number of pages | 8 |
Journal | Chemosphere |
Volume | 84 |
Issue number | 6 |
DOIs | |
State | Published - Aug 2011 |
Keywords
- Adsorption
- Biological uptake
- Ion exchange
- Phosphorus
- Precipitation
- Recovery
ASJC Scopus subject areas
- General Chemistry
- Public Health, Environmental and Occupational Health
- Pollution
- Health, Toxicology and Mutagenesis
- Environmental Engineering
- Environmental Chemistry