{"paper_id":"1b1ab161-d71c-4cec-ac1a-6bac2dbdf495","body_text":"Using response surface methodology to optimize the operating parameters on the sorption of cadmium and surface area of the adsorbent | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Using response surface methodology to optimize the operating parameters on the sorption of cadmium and surface area of the adsorbent S. Meski, H. Khireddine This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7870444/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract In this study, the adsorption of cadmium ions from aqueous solution onto hydroxyapatite was investigated. A series of apatite powders were synthesized under varying conditions of reaction time, reaction temperature and calcination temperature. In addition, the surface area (S BET ) of each synthetized powders were measured. To model and optimize both the cadmium adsorption efficiency and the surface area of the prepared apatite, response surface methodology (RSM) was employed. three variables were considered such as: reaction time (time: 1-96 h), reaction temperature (T Sol : 20-70°C) and calcination temperature (T Cal : 45-655°C). The pH reaction was fixed at 9. The regression models developed showed good agreement with the experimental data, as indicated by high R 2 values, confirming the adequacy of the fitted models. The optimal conditions for achieving the maximum surface area (S BET ) of 98 m 2 /g were found be: calcination temperature (T Cal ) of 354.26°C, reaction temperature (T Sol ) of 41.036°C and maturation time of 48h. For cadmium adsorption, the maximum adsorption yield was obtained for T Cal = 235°C, T Sol = 17.5°C and time =48h. In the second step, anew parameter such as reaction pH was introduced to study its effect on cadmium removal. The results indicated that when the pH exceeded 9, cadmium removal efficiency decreased, while the maximum adsorption was observed at pH= 8.5. cadmium Doehlert matrix hydroxyapatite statistical modeling Sorption Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-7870444\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":true,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":530638172,\"identity\":\"071741a9-e2ea-4149-8485-2f3cc165944a\",\"order_by\":0,\"name\":\"S. 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A series of apatite powders were synthesized under varying conditions of reaction time, reaction temperature and calcination temperature. In addition, the surface area (S\\u003csub\\u003eBET\\u003c/sub\\u003e) of each synthetized powders were measured. To model and optimize both the cadmium adsorption efficiency and the surface area of the prepared apatite, response surface methodology (RSM) was employed.\\u003c/p\\u003e\\n\\u003cp\\u003ethree variables were considered such as: reaction time (time: 1-96 h), reaction temperature (T\\u003csub\\u003eSol\\u003c/sub\\u003e: 20-70°C) and calcination temperature (T\\u003csub\\u003eCal\\u003c/sub\\u003e: 45-655°C). The pH reaction was fixed at 9. The regression models developed showed good agreement with the experimental data, as indicated by high R\\u003csup\\u003e2\\u003c/sup\\u003e values, confirming the adequacy of the fitted models.\\u003c/p\\u003e\\n\\u003cp\\u003eThe optimal conditions for achieving the maximum surface area (S\\u003csub\\u003eBET\\u003c/sub\\u003e) of 98 m\\u003csup\\u003e2\\u003c/sup\\u003e/g were found be: calcination temperature (T\\u003csub\\u003eCal\\u003c/sub\\u003e) of 354.26°C, reaction temperature (T\\u003csub\\u003eSol\\u003c/sub\\u003e) of 41.036°C and maturation time of 48h. For cadmium adsorption, the maximum adsorption yield was obtained for\\u0026nbsp;\\u0026nbsp;\\u0026nbsp; T\\u003csub\\u003eCal\\u003c/sub\\u003e = 235°C, T\\u003csub\\u003eSol\\u003c/sub\\u003e = 17.5°C and time =48h.\\u003c/p\\u003e\\n\\u003cp\\u003eIn the second step, anew parameter such as reaction pH was introduced to study its effect on cadmium removal. The results indicated that when the pH exceeded 9, cadmium removal efficiency decreased, while the maximum adsorption was observed at pH= 8.5.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Using response surface methodology to optimize the operating parameters on the sorption of cadmium and surface area of the adsorbent\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2025-10-17 12:47:44\",\"doi\":\"10.21203/rs.3.rs-7870444/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"4940731a-df40-4727-bb04-61c9a09bd538\",\"owner\":[],\"postedDate\":\"October 17th, 2025\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"posted\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2025-10-22T06:23:20+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2025-10-17 12:47:44\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-7870444\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-7870444\",\"identity\":\"rs-7870444\",\"version\":[\"v1\"]},\"buildId\":\"8U1c8b4HqxoKbykW_rLl7\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}