{"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"}}, {"id": "10044/1/108326", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-20T16:21:36Z", "type": "Journal Article", "created": "2023-11-30", "title": "Do contaminants compromise the use of recycled nutrients in organic agriculture? A review and synthesis of current knowledge on contaminant concentrations, fate in the environment and risk assessment", "description": "Use of nutrients recycled from societal waste streams in agriculture is part of the circular economy, and in line with organic farming principles. Nevertheless, diverse contaminants in waste streams create doubts among organic farmers about potential risks for soil health. Here, we gather the current knowledge on contaminant levels in waste streams and recycled nutrient sources, and discuss associated risks. For potentially toxic elements (PTEs), the input of zinc (Zn) and copper (Cu) from mineral feed supplements remains of concern, while concentrations of PTEs in many waste streams have decreased substantially in Europe. The same applies to organic contaminants, although new chemical groups such as flame retardants are of emerging concern and globally contamination levels differ strongly. Compared to inorganic fertilizers, application of organic fertilizers derived from human or animal feces is associated with an increased risk for environmental dissemination of antibiotic resistance. The risk depends on the quality of the organic fertilizers, which varies between geographical regions, but farmland application of sewage sludge appears to be a safe practice as shown by some studies (e.g. from Sweden). Microplastic concentrations in agricultural soils show a wide spread and our understanding of its toxicity is limited, hampering a sound risk assessment. Methods for assessing public health risks for organic contaminants must include emerging contaminants and potential interactions of multiple compounds. Evidence from long-term field experiments suggests that soils may be more resilient and capable to degrade or stabilize pollutants than often assumed. In view of the need to source nutrients for expanding areas under organic farming, we discuss inputs originating from conventional farms vs. non-agricultural (i.e. societal) inputs. Closing nutrient cycles between agriculture and society is feasible in many cases, without being compromised by contaminants, and should be enhanced, aided by improved source control, waste treatment and sound risk assessments.", "keywords": ["Organic farming", "SEWAGE-SLUDGE", "LONG-TERM IMPACT", "PATHOGENIC BACTERIA", "Environmental Sciences & Ecology", "Risk Assessment", "630", "Societal wastes", "12. Responsible consumption", "Organic contaminants", "Soil", "PRE-APPLICATION TREATMENT", "HEAVY-METALS", "ANAEROBIC-DIGESTION", "11. Sustainability", "Animals", "Humans", "Soil Pollutants", "Fertilizers", "Risk assessment", "2. Zero hunger", "Organic Agriculture", "Science & Technology", "Sewage", "ANTIBIOTIC-RESISTANCE GENES", "FERTILIZER VALUE", "SOIL DYNAMICS", "Agriculture", "Nutrients", "15. Life on land", "6. Clean water", "13. Climate action", "BACTERIAL COMMUNITIES", "Life Sciences & Biomedicine", "Plastics", "Environmental Sciences"]}, "links": [{"href": "https://doi.org/10044/1/108326"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Science%20of%20The%20Total%20Environment", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10044/1/108326", "name": "item", "description": "10044/1/108326", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10044/1/108326"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2024-02-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=ANAEROBIC-DIGESTION&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=ANAEROBIC-DIGESTION&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=ANAEROBIC-DIGESTION&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=ANAEROBIC-DIGESTION&offset=2", "hreflang": "en-US"}], "numberMatched": 2, "numberReturned": 2, "distributedFeatures": [], "timeStamp": "2026-09-21T07:43:08.763676Z"}