{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,3]],"date-time":"2026-02-03T22:28:49Z","timestamp":1770157729111,"version":"3.49.0"},"reference-count":31,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T00:00:00Z","timestamp":1769731200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Resources"],"abstract":"<jats:p>The lack of interest in the reuse of phosphorus in agriculture is mainly due to the high abundance of pathogens, organic pollutants, microplastics, and possibly toxic metals. Therefore, different forms of treatment are necessary to take advantage of phosphorus recovery potential, one of which is the use of ash from incinerated\/calcined biological sludge. A high rate of conversion of the non-apatite inorganic phosphorus fraction into apatite phosphorus was obtained in this study because of the use of commercially pure CaO additive in the dry sludge calcination tests, which is more bioavailable to plants. The obtained phosphorus pentoxide content ranged from 12 to 17%, surpassing several phosphorus-based raw materials and fertilizers. In addition, the ashes have been shown to contain toxic metals far below those recommended by Brazilian and international environmental legislation, so they can be applied directly to the soil for crop fertilization, or be used in P extraction and separation technologies for fertilizer production.<\/jats:p>","DOI":"10.3390\/resources15020022","type":"journal-article","created":{"date-parts":[[2026,1,30]],"date-time":"2026-01-30T13:04:46Z","timestamp":1769778286000},"page":"22","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Characterization of Phosphorus Recovered from Sewage Sludge Ash: A Brazil Case Study"],"prefix":"10.3390","volume":"15","author":[{"given":"Jo\u00e3o","family":"Garcia","sequence":"first","affiliation":[{"name":"Institute of Science and Technology, S\u00e3o Paulo State University (UNESP), Sorocaba 18087-180, SP, Brazil"}]},{"given":"Rafael","family":"Lima","sequence":"additional","affiliation":[{"name":"Institute of Science and Technology, S\u00e3o Paulo State University (UNESP), Sorocaba 18087-180, SP, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3410-6482","authenticated-orcid":false,"given":"Pedro","family":"Resende","sequence":"additional","affiliation":[{"name":"CEFT\u2014Transport Phenomena Research Center, Department of Mechanical Engineering, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"},{"name":"proMetheus, Escola Superior de Tecnologia e Gest\u00e3o, Instituto Polit\u00e9cnico de Viana do Castelo, 4900-347 Viana do Castelo, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2042-018X","authenticated-orcid":false,"given":"Andr\u00e9","family":"Rosa","sequence":"additional","affiliation":[{"name":"Institute of Science and Technology, S\u00e3o Paulo State University (UNESP), Sorocaba 18087-180, SP, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2825-0709","authenticated-orcid":false,"given":"Alexandre","family":"Afonso","sequence":"additional","affiliation":[{"name":"CEFT\u2014Transport Phenomena Research Center, Department of Mechanical Engineering, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1468-5453","authenticated-orcid":false,"given":"Leandro","family":"Morais","sequence":"additional","affiliation":[{"name":"Institute of Science and Technology, S\u00e3o Paulo State University (UNESP), Sorocaba 18087-180, SP, Brazil"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1016\/j.gloenvcha.2008.10.009","article-title":"The story of phosphorus: Global food security and food for thought","volume":"19","author":"Cordell","year":"2009","journal-title":"Glob. Environ. Chang."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1007\/s12571-015-0442-0","article-title":"Tracking phosphorus security: Indicators of phosphorus vulnerability in the global food system","volume":"7","author":"Cordell","year":"2015","journal-title":"Food Secur."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1016\/j.scitotenv.2016.10.078","article-title":"Insight into chemical phosphate recovery from municipal wastewater","volume":"576","author":"Ye","year":"2017","journal-title":"Sci. Total Environ."},{"key":"ref_4","unstructured":"Rosa, A.H., Fraceto, L.F., and Carlos, V.M. (2012). Meio Ambiente e Sustentabilidade, Grupo A. [1st ed.]."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"118683","DOI":"10.1016\/j.jece.2025.118683","article-title":"Triple superphosphate based on sewage sludge ash and chicken manure ash\u2014production and agronomic usefulness","volume":"13","author":"Sawska","year":"2025","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"522","DOI":"10.1016\/j.scitotenv.2016.07.019","article-title":"Phosphorus recovery from municipal wastewater: An integrated comparative technological, environmental and economic assessment of P recovery technologies","volume":"571","author":"Eagle","year":"2016","journal-title":"Sci. Total Environ."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2375","DOI":"10.5433\/1679-0359.2022v43n5p2375","article-title":"Evaluation of the use of wastewater treated with Lemnas minor in bean yield and nutrition","volume":"43","author":"Lima","year":"2022","journal-title":"Semin. Ci\u00eanc. Agr\u00e1r."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"107054","DOI":"10.1016\/j.jwpe.2025.107054","article-title":"Evaluation of the potential use of sewage sludge ash in phosphoric acid production and phosphorus recovery technologies","volume":"70","author":"Kominko","year":"2025","journal-title":"J. Water Process Eng."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"100015","DOI":"10.1016\/j.cejgas.2025.100015","article-title":"Sewage sludge: A source of renewable energy and resources for circular bioeconomy","volume":"1","author":"Olasupo","year":"2026","journal-title":"Chem. Eng. J. Green Sustain."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1728","DOI":"10.1016\/j.jclepro.2016.11.116","article-title":"A review of phosphorus recovery methods at various steps of wastewater treatment and sewage sludge management. The concept of \u201cno solid waste generation\u201d and analytical methods","volume":"142","author":"Cieslik","year":"2017","journal-title":"J. Clean. Prod."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"115090","DOI":"10.1016\/j.jenvman.2022.115090","article-title":"Sewage sludge treatment methods and P-recovery possibilities: Current state-of-the-art","volume":"315","author":"Husek","year":"2022","journal-title":"J. Environ. Manag."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"109268","DOI":"10.1016\/j.jenvman.2019.109268","article-title":"Phosphorus recovery from municipal wastewater treatment: Critical review of challenges and opportunities for developing countries","volume":"248","author":"Chrispim","year":"2019","journal-title":"J. Environ. Manag."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Gerardi, M.H. (2006). Wastewater Bacteria, Wiley-Intersciense.","DOI":"10.1002\/0471979910"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"104","DOI":"10.17221\/36\/2018-SWR","article-title":"Present restrictions of sewage sludge application in agriculture within the European Union","volume":"14","author":"Vymazal","year":"2019","journal-title":"Soil Water Recearch"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"964","DOI":"10.1016\/j.jclepro.2016.06.177","article-title":"Potential recovery of phosphorus during the fluidized bed incineration of sewage sludge","volume":"140","author":"Li","year":"2017","journal-title":"J. Clean. Prod."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"644","DOI":"10.1016\/j.wasman.2019.06.029","article-title":"Phosphorus recovery from sewage sludge via incineration with chlorine-based additives","volume":"95","author":"Yang","year":"2019","journal-title":"Waste Manag."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"125874","DOI":"10.1016\/j.jclepro.2021.125874","article-title":"A solution to the limited global phosphorus supply: Regionalization of phosphorus recovery from sewage sludge ash","volume":"290","author":"Law","year":"2021","journal-title":"J. Clean. Prod."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/j.chemosphere.2015.05.094","article-title":"Transformation of apatite phosphorus and non-apatite inorganic phosphorus during incineration of sewage sludge","volume":"141","author":"Li","year":"2015","journal-title":"Chemosphere"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1007\/s00216-003-1897-y","article-title":"Relationships between phosphorus fractionation and major components in sediments using the SMT harmonized extraction procedure","volume":"376","author":"Pardo","year":"2003","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"224","DOI":"10.1007\/s002160100753","article-title":"Harmonized protocol and certified reference material for the determination of extractable contents of phosphorus in freshwaters sediments","volume":"370","author":"Ruban","year":"2001","journal-title":"Fresenius\u2019 J. Anal. Chem."},{"key":"ref_21","unstructured":"American Public Health Association (APHA) (1995). 4500-p Phosphorus: Standard Methods for the Examination of Water and Wastewater, American Public Health Association."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"556","DOI":"10.1590\/S0100-40422008000300018","article-title":"Influ\u00eancia de m\u00e9todos de digest\u00e3o e massa de amostra na recupera\u00e7\u00e3o de nutrientes em res\u00edduos org\u00e2nicos","volume":"31","author":"Melo","year":"2008","journal-title":"Qu\u00edm. Nova"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/j.jclepro.2018.03.276","article-title":"New advancement perspectives of chloride additives on enhanced heavy metals removal and phosphorus fixation during thermal processing of sewage sludge","volume":"188","author":"Bairq","year":"2018","journal-title":"J. Clean. Prod."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1504\/IJEP.2009.026054","article-title":"The behavior of phosphorus and heavy metals in sewage sludge ashes","volume":"37","author":"Han","year":"2009","journal-title":"Int. J. Environ. E Pollut."},{"key":"ref_25","unstructured":"CETESB (2021). Aplica\u00e7\u00e3o de Lodo de Sistemas de Tratamento biol\u00f3Gico de Efluentes l\u00edQuidos sanit\u00e1Rios em Solo\u2014Diretrizes e Crit\u00e9rios Para Projeto e Opera\u00e7\u00e3o."},{"key":"ref_26","unstructured":"CONAMA (2006). Define Crit\u00e9rios e Procedimentos, Para o Usoagr\u00edcola de Lodos de Esgoto Gerados em Esta\u00e7\u00f5es Detratamento de Esgoto Sanit\u00e1rio e Seus Produtosderivados, e d\u00e1 Outras Provid\u00eancias."},{"key":"ref_27","unstructured":"Malavolta, E., Morais, M.F., J\u00fanior, J.L., and Malavolta, M. (2006). Micronutirentes e Metais Pesados\u2014Essencialidade e Toxidez; Ci\u00eancia, Agricultura e Sociedade."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1122","DOI":"10.1016\/j.wasman.2008.09.011","article-title":"Thermochemical treatment of sewage sludge ashes for phosphorus recovery","volume":"29","author":"Adam","year":"2009","journal-title":"Waste Manag."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"108117","DOI":"10.1016\/j.jece.2022.108117","article-title":"Recovery of phosphorus from sewage sludge ash: Influence of chemical addition prior to incineration on ash mineralogy and related phosphorus and heavy metal extraction","volume":"10","author":"Luyckx","year":"2022","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_30","unstructured":"Luz, A.B., Fran\u00e7a, S.C.A., and Braga, P.F.A. (2018). Tratamento de Min\u00e9rios."},{"key":"ref_31","unstructured":"Morais, L.C. (2006). Caracteriza\u00e7\u00e3o, em Escala de Laborat\u00f3rio, do Produto Proveniente da Calcina\u00e7\u00e3o do Lodo de Esgoto Resultante do Tratamento de \u00e1guas Residu\u00e1rias. [Ph.D. Thesis, University of S\u00e3o Paulo]."}],"container-title":["Resources"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-9276\/15\/2\/22\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,3]],"date-time":"2026-02-03T09:30:55Z","timestamp":1770111055000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-9276\/15\/2\/22"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,30]]},"references-count":31,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,2]]}},"alternative-id":["resources15020022"],"URL":"https:\/\/doi.org\/10.3390\/resources15020022","relation":{},"ISSN":["2079-9276"],"issn-type":[{"value":"2079-9276","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,30]]}}}