{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:43:44Z","timestamp":1760237024042,"version":"build-2065373602"},"reference-count":15,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2020,2,14]],"date-time":"2020-02-14T00:00:00Z","timestamp":1581638400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100010665","name":"H2020 Marie Sk\u0142odowska-Curie Actions","doi-asserted-by":"publisher","award":["778045"],"award-info":[{"award-number":["778045"]}],"id":[{"id":"10.13039\/100010665","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011011","name":"Junta de Andaluc\u00eda","doi-asserted-by":"publisher","award":["UMA18-FEDERJA-279"],"award-info":[{"award-number":["UMA18-FEDERJA-279"]}],"id":[{"id":"10.13039\/501100011011","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100009473","name":"Universidad de M\u00e1laga","doi-asserted-by":"publisher","award":["PPIT.UMA.B5.2018\/17"],"award-info":[{"award-number":["PPIT.UMA.B5.2018\/17"]}],"id":[{"id":"10.13039\/100009473","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>Zero valent iron (ZVI) is being used in permeable reactive barriers (PRB) for the removal of oxidant contaminants, from nitrate to chlorinated organics. A sound design of these barriers requires a good understanding of kinetics. Here we present a study of the kinetics of nitrate reduction under relatively low values of pH, from 2 to 4.5. We use a particle size of 0.42 mm, which is within the recommended size for PRBs (0.2 mm to 2.0 mm). In order to avoid possible mass-transfer limitations, a well-stirred reactor coupled with a fluidized bed reactor was used. The experiments were performed at constant pH values using a pH controller that allows to accurately track the amount of acid added. Since the reduction of      H +      to      H 2      by the oxidation of ZVI will always be present for these pH values, blank experiments (without nitrate) were performed and the rate of this      H +      reduction obtained. This rate of reduction was studied using three kinetic models: a regular empirical one, the Shrinking-Core Model (SCM), and the Surface Kinetics Model (SKM). The best performance was obtained from the SKM model. Therefore, this model was also used to study the results for the nitrate reduction, also with satisfactory results. In both cases, some assumptions are introduced to maintain a moderate number of fitting parameters.<\/jats:p>","DOI":"10.3390\/ijerph17041241","type":"journal-article","created":{"date-parts":[[2020,2,19]],"date-time":"2020-02-19T04:06:01Z","timestamp":1582085161000},"page":"1241","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Chemical Reduction of Nitrate by Zero-Valent Iron: Shrinking-Core versus Surface Kinetics Models"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4256-5523","authenticated-orcid":false,"given":"Maria","family":"Villen-Guzman","sequence":"first","affiliation":[{"name":"Department of Chemical Engineering, University of Malaga, 29071 Malaga, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1464-6975","authenticated-orcid":false,"given":"Juan Manuel","family":"Paz-Garcia","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Malaga, 29071 Malaga, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Brahim","family":"Arhoun","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Malaga, 29071 Malaga, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8050-3569","authenticated-orcid":false,"given":"Maria del Mar","family":"Cerrillo-Gonzalez","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Malaga, 29071 Malaga, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1492-6299","authenticated-orcid":false,"given":"Jose Miguel","family":"Rodriguez-Maroto","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Malaga, 29071 Malaga, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5216-6796","authenticated-orcid":false,"given":"Carlos","family":"Vereda-Alonso","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Malaga, 29071 Malaga, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cesar","family":"Gomez-Lahoz","sequence":"additional","affiliation":[{"name":"Department of Chemical Engineering, University of Malaga, 29071 Malaga, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,2,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"958","DOI":"10.1111\/j.1745-6584.1994.tb00935.x","article-title":"Enhanced Degradation of Halogenated Aliphatics by Zero-Valent Iron","volume":"32","author":"Gillham","year":"1994","journal-title":"Groundwater"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"164","DOI":"10.1111\/j.1745-6584.1998.tb01077.x","article-title":"Long-Term Performance of an In Situ \u201cIron Wall\u201d for Remediation of VOCs","volume":"36","author":"Gillham","year":"1998","journal-title":"Groundwater"},{"key":"ref_3","unstructured":"Naidu, R., and Volker, B. 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Mater."}],"container-title":["International Journal of Environmental Research and Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-4601\/17\/4\/1241\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T08:57:58Z","timestamp":1760173078000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-4601\/17\/4\/1241"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,2,14]]},"references-count":15,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2020,2]]}},"alternative-id":["ijerph17041241"],"URL":"https:\/\/doi.org\/10.3390\/ijerph17041241","relation":{},"ISSN":["1660-4601"],"issn-type":[{"type":"electronic","value":"1660-4601"}],"subject":[],"published":{"date-parts":[[2020,2,14]]}}}