{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T18:04:05Z","timestamp":1785434645012,"version":"3.56.0"},"reference-count":37,"publisher":"Public Library of Science (PLoS)","issue":"7","license":[{"start":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T00:00:00Z","timestamp":1785369600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>\n                    This study evaluates the adsorption performance of an Iranian bentonite modified through two routes: activation with HNO\n                    <jats:sub>3<\/jats:sub>\n                    followed by calcination at 500 \u00b0C yielding NWF adsorbent and activation with HCl followed by chitosan intercalation to obtain HWF adsorbent. Batch experiments assessed Cu\n                    <jats:sup>2+<\/jats:sup>\n                    and Zn\n                    <jats:sup>2+<\/jats:sup>\n                    removal from aqueous solutions under varying pH, contact time (5\u201345\u2009min), sorbent dosage (10\u2013150\u2009mg), initial concentration (20\u2013200\u2009mg\/L), and temperatures (20\u201345\u00b0C). Atomic Absorption Spectroscopy was used to evaluate heavy metal concentrations. Nonlinear isotherm fitting showed that the Langmuir model described the data well with high mass normalized capacities under the low-dose condition. Freundlich fits indicated favorable adsorption on heterogeneous surfaces. Kinetics followed the pseudo-second-order model (R\u00b2\u2009=\u20090.996\u20130.998), could be described by chemisorption and in case of NWF, faster uptake (higher k\n                    <jats:sub>2<\/jats:sub>\n                    ) achieved. Optimal adsorption performance occurred at a pH of approximately 6\u20137, achieving equilibrium capacities (\n                    <jats:italic>q<\/jats:italic>\n                    <jats:sub>\n                      <jats:italic>e<\/jats:italic>\n                    <\/jats:sub>\n                    ) as high as 99.0\u2009mg\/g and blank tests at pH\u2009\u2265\u20098 minimized contributions from metal hydroxide precipitation. Thermodynamic analysis has been carried out to confirm spontaneous and endothermic adsorption in temptatures ranged from 20\u201345\u00b0C. X-ray Diffraction, Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy corroborated successful modification and enhanced site accessibility. The results of this study showed that acid-activated and chitosan-modified bentonites are low-cost, effective, and sustainable sorbents for Cu\n                    <jats:sup>2+<\/jats:sup>\n                    and Zn\n                    <jats:sup>2+<\/jats:sup>\n                    removal from water, with practical relevance to wastewater treatment.\n                  <\/jats:p>","DOI":"10.1371\/journal.pone.0344207","type":"journal-article","created":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T17:42:42Z","timestamp":1785433362000},"page":"e0344207","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Acid-activated chitosan-modified Iranian bentonite for adsorption of Cu(II) and Zn(II) from water; A green and sustainable water treatment approach"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-7998-7866","authenticated-orcid":true,"given":"Sam","family":"Daftari","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8982-1945","authenticated-orcid":true,"given":"Mojgan","family":"Salavati","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Manoochehr Mortazavi","family":"Chamchali","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,7,30]]},"reference":[{"key":"pone.0344207.ref001","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1016\/S0304-3894(02)00263-7","article-title":"Low-cost adsorbents for heavy metals uptake from contaminated water: a review","volume":"97","author":"S Babel","year":"2003","journal-title":"J Hazard 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