{"type": "FeatureCollection", "features": [{"id": "10.1007/s11356-020-10918-6", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-20T16:14:49Z", "type": "Journal Article", "created": "2020-10-03", "title": "Study of pig manure digestate pre-treatment for subsequent valorisation by struvite", "description": "Abstract<p>This work evaluates the release of phosphorus contained in the digestate from the anaerobic digestion of pig manure, through an acidification process. The objective of this acidification is to increase the amount of phosphorus available in the digestate liquid fraction and, subsequently, recover this element by chemical precipitation in the form of struvite or calcium phosphate. Two digestate samples (one fresh and one old) were studied and treated by adding various amounts of sulphuric acid to the different digestate fractions (raw digestate, solid fraction and liquid fraction). For the raw digestate, phosphorus releases higher than 95% were obtained for pH 4.0. In the last part of the experiment, the influence of acid pre-treatment on the reaction yield of phosphorus precipitation, in the form of struvite or calcium phosphate, was determined. Improvements in reaction yield were obtained up to 15% for struvite and 80% for calcium phosphate, increasing also in 7.5 times the amount of phosphorus available in the digestate liquid fraction, for both cases.</p>", "keywords": ["Biofertiliser", "FEASIBILITY", "NUTRIENT RECOVERY", "PH", "Struvite", "Swine", "SWINE WASTE-WATER", "0211 other engineering and technologies", "02 engineering and technology", "7. Clean energy", "01 natural sciences", "CALCIUM", "Acidification", "ANAEROBIC-DIGESTION", "Environmental Chemistry", "PHOSPHORUS REMOVAL", "Animals", "Chemical Precipitation", "Toxicology and Mutagenesis", "Anaerobiosis", "Organic waste", "SLUDGE", "0105 earth and related environmental sciences", "Phosphorus", "General Medicine", "Pollution", "6. Clean water", "Manure", "Nutrient recovery", "Health", "Earth and Environmental Sciences", "Release", "PRECIPITATION", "Waste and Biomass Management & Valorization", "CRYSTALLIZATION"]}, "links": [{"href": "https://link.springer.com/content/pdf/10.1007/s11356-020-10918-6.pdf"}, {"href": "https://doi.org/10.1007/s11356-020-10918-6"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Environmental%20Science%20and%20Pollution%20Research", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s11356-020-10918-6", "name": "item", "description": "10.1007/s11356-020-10918-6", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s11356-020-10918-6"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2020-10-03T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=SWINE+WASTE-WATER&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=SWINE+WASTE-WATER&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=SWINE+WASTE-WATER&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=SWINE+WASTE-WATER&offset=1", "hreflang": "en-US"}], "numberMatched": 1, "numberReturned": 1, "distributedFeatures": [], "timeStamp": "2026-09-21T07:42:45.558942Z"}