{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,23]],"date-time":"2026-01-23T15:49:11Z","timestamp":1769183351051,"version":"3.49.0"},"reference-count":54,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2022,2,15]],"date-time":"2022-02-15T00:00:00Z","timestamp":1644883200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["PTDC-CTM-CTM-2205-2020"],"award-info":[{"award-number":["PTDC-CTM-CTM-2205-2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["2020.01135.CEECIND"],"award-info":[{"award-number":["2020.01135.CEECIND"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["SFRH\/BD\/144562\/2019"],"award-info":[{"award-number":["SFRH\/BD\/144562\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["UIDB\/50011\/2020 & UIDP\/50011\/2020"],"award-info":[{"award-number":["UIDB\/50011\/2020 & UIDP\/50011\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>In this work, alkali-activated fly ash-derived foams were produced at room temperature by direct foaming using aluminum powder. The 1 cm3 foams (cubes) were then evaluated as adsorbents to extract heavy metals from aqueous solutions. The foams\u2019 selectivity towards lead, cadmium, zinc, and copper ions was evaluated in single, binary, and multicomponent ionic solutions. In the single ion assays, the foams showed much higher affinity towards lead, compared to the other heavy metals; at 10 ppm, the removal efficiency reached 91.9% for lead, 83.2% for cadmium, 74.6% for copper, and 64.6% for zinc. The greater selectivity for lead was also seen in the binary tests. The results showed that the presence of zinc is detrimental to cadmium and copper sorption, while for lead it mainly affects the sorption rate, but not the ultimate removal efficiency. In the multicomponent assays, the removal efficiency for all the heavy metals was lower than the values seen in the single ion tests. However, the superior affinity for lead was preserved. This study decreases the existing knowledge gap regarding the potential of alkali-activated materials to act as heavy metals adsorbents under different scenarios.<\/jats:p>","DOI":"10.3390\/ma15041453","type":"journal-article","created":{"date-parts":[[2022,2,15]],"date-time":"2022-02-15T22:44:47Z","timestamp":1644965087000},"page":"1453","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["Unravelling the Affinity of Alkali-Activated Fly Ash Cubic Foams towards Heavy Metals Sorption"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4261-0408","authenticated-orcid":false,"given":"Ana P. F.","family":"Caetano","sequence":"first","affiliation":[{"name":"Department of Materials and Ceramic Engineering\/CICECO-Aveiro Institute of Materials, University of Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8337-618X","authenticated-orcid":false,"given":"Jo\u00e3o","family":"Carvalheiras","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering\/CICECO-Aveiro Institute of Materials, University of Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"given":"Luciano","family":"Senff","sequence":"additional","affiliation":[{"name":"Department of Mobility Engineering, Federal University of Santa Catarina (UFSC), Joinville 89219-600, SC, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5174-7433","authenticated-orcid":false,"given":"Maria P.","family":"Seabra","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering\/CICECO-Aveiro Institute of Materials, University of Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"given":"Robert C.","family":"Pullar","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering\/CICECO-Aveiro Institute of Materials, University of Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"},{"name":"Department of Molecular Sciences and Nanosystems (DSMN), Ca\u2019 Foscari University of Venice, Scientific Campus, Via Torino 155, 30172 Venice Mestre, Italy"}]},{"given":"Jo\u00e3o A.","family":"Labrincha","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering\/CICECO-Aveiro Institute of Materials, University of Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5698-9135","authenticated-orcid":false,"given":"Rui M.","family":"Novais","sequence":"additional","affiliation":[{"name":"Department of Materials and Ceramic Engineering\/CICECO-Aveiro Institute of Materials, University of Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e1500323","DOI":"10.1126\/sciadv.1500323","article-title":"Sustainability: Four billion people facing severe water scarcity","volume":"2","author":"Mekonnen","year":"2016","journal-title":"Sci. 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