Optimizing the removal of ciprofloxacin from aqueous solutions using an advanced oxidation process (TiO₂/Fe₃O₄/UVA) and evaluating toxicity via the biological reduction method of resazurin dye

Optimizing the removal of ciprofloxacin from aqueous solutions using an advanced oxidation process (TiO₂/Fe₃O₄/UVA) and evaluating toxicity via the biological reduction method of resazurin dye | 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 Article Optimizing the removal of ciprofloxacin from aqueous solutions using an advanced oxidation process (TiO₂/Fe₃O₄/UVA) and evaluating toxicity via the biological reduction method of resazurin dye Mansour Ghaderpoori, Maryam Yaghobi, Faramarz Azimi, Bahram Kamarehie, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7727240/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 18 You are reading this latest preprint version Abstract Ciprofloxacin (CIP), due to its high chemical stability and widespread occurrence in aquatic environments, has emerged as a significant environmental pollutant. Even at low concentrations, it poses a serious threat to human health and ecosystems. Therefore, the present study aims to optimize the photocatalytic degradation of CIP and evaluate the toxicity of the treated effluent obtained from aqueous solutions. This experimental laboratory study was carried out in batch mode using a photocatalytic process in a reactor with an approximate volume of 3 liters. The optimization of experiments was conducted using the Central Composite Design (CCD). In this design, the variables pH, contact time, CIP concentration, and dose of nanoparticles (NP S ) were investigated. TiO₂/Fe₃O₄ nanocomposites were synthesized using the sol-gel method. The structure, morphology, and elemental analysis of the TiO₂/Fe₃O₄ nanocomposites were evaluated using SEM, Fourier Transform Infrared Spectroscopy FTIR, and EDX analysis. In this study, the residual concentration of CIP was measured using a HPLC device according to the designed experimental runs. Additionally, the toxicity of the effluent was assessed using the resazurin colorimetric assay based on the bacterial activity of E. coli . The results obtained from this study showed that spherical nanoparticles with a relatively uniform size distribution and no aggregation were produced. Based on the CCD model, under the optimal experimental conditions, including a contact time of 85.76 min, pH of 7.7, an initial CIP concentration of 13.44 mg/L, and a nanocomposite dose of 289.64 mg/L, the removal efficiency of CIP reached approximately 95%. Additionally, the analysis of variance (ANOVA) showed that the second-order regression model with a very high coefficient of determination (R² = 0.9895) provided the best fit to the data. The toxicity assessment of the effluent from the reactor showed that the EC₅₀, 100% mortality concentration, and no observed inhibitory effect concentration (NOEC) for E. coli were 1.37, 2.55, and 0.92 mg/L, respectively. The results of this study showed that the synthesized nanocomposite, along with UV radiation, is an effective and stable option for treating wastewater contaminated with emerging pollutants such as antibiotics. It can be scaled up for large-scale applications in environmental protection and to ensure compliance with effluent discharge standards. Physical sciences/Chemistry Earth and environmental sciences/Environmental sciences Ciprofloxacin. Photocatalytic processes. Optimization. Resazurin. E. coli Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 09 Oct, 2025 Reviewers agreed at journal 06 Oct, 2025 Reviews received at journal 06 Oct, 2025 Reviews received at journal 04 Oct, 2025 Reviews received at journal 04 Oct, 2025 Reviewers agreed at journal 03 Oct, 2025 Reviewers agreed at journal 03 Oct, 2025 Reviewers agreed at journal 03 Oct, 2025 Reviewers agreed at journal 03 Oct, 2025 Reviewers agreed at journal 03 Oct, 2025 Reviewers agreed at journal 03 Oct, 2025 Reviewers agreed at journal 03 Oct, 2025 Reviewers agreed at journal 03 Oct, 2025 Reviewers invited by journal 03 Oct, 2025 Editor invited by journal 03 Oct, 2025 Editor assigned by journal 30 Sep, 2025 Submission checks completed at journal 29 Sep, 2025 First submitted to journal 27 Sep, 2025 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-7727240","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":526880780,"identity":"4a8b3dec-dcf1-4792-afa5-4c572e287090","order_by":0,"name":"Mansour Ghaderpoori","email":"","orcid":"","institution":"Lorestan University of Medical Sciences","correspondingAuthor":false,"prefix":"","firstName":"Mansour","middleName":"","lastName":"Ghaderpoori","suffix":""},{"id":526880782,"identity":"78f9388c-b61f-491f-bdb0-ea2e63f8ccbb","order_by":1,"name":"Maryam Yaghobi","email":"","orcid":"","institution":"Lorestan University of Medical 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Photocatalytic processes. Optimization. Resazurin. E. coli","lastPublishedDoi":"10.21203/rs.3.rs-7727240/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7727240/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eCiprofloxacin (CIP), due to its high chemical stability and widespread occurrence in aquatic environments, has emerged as a significant environmental pollutant. Even at low concentrations, it poses a serious threat to human health and ecosystems. Therefore, the present study aims to optimize the photocatalytic degradation of CIP and evaluate the toxicity of the treated effluent obtained from aqueous solutions. This experimental laboratory study was carried out in batch mode using a photocatalytic process in a reactor with an approximate volume of 3 liters. The optimization of experiments was conducted using the Central Composite Design (CCD). In this design, the variables pH, contact time, CIP concentration, and dose of nanoparticles (NP\u003csub\u003eS\u003c/sub\u003e) were investigated. TiO₂/Fe₃O₄ nanocomposites were synthesized using the sol-gel method. The structure, morphology, and elemental analysis of the TiO₂/Fe₃O₄ nanocomposites were evaluated using SEM, Fourier Transform Infrared Spectroscopy FTIR, and EDX analysis. In this study, the residual concentration of CIP was measured using a HPLC device according to the designed experimental runs. Additionally, the toxicity of the effluent was assessed using the resazurin colorimetric assay based on the bacterial activity of \u003cem\u003eE. coli\u003c/em\u003e. The results obtained from this study showed that spherical nanoparticles with a relatively uniform size distribution and no aggregation were produced. Based on the CCD model, under the optimal experimental conditions, including a contact time of 85.76 min, pH of 7.7, an initial CIP concentration of 13.44 mg/L, and a nanocomposite dose of 289.64 mg/L, the removal efficiency of CIP reached approximately 95%. Additionally, the analysis of variance (ANOVA) showed that the second-order regression model with a very high coefficient of determination (R\u0026sup2; = 0.9895) provided the best fit to the data. The toxicity assessment of the effluent from the reactor showed that the EC₅₀, 100% mortality concentration, and no observed inhibitory effect concentration (NOEC) for \u003cem\u003eE. coli\u003c/em\u003e were 1.37, 2.55, and 0.92 mg/L, respectively. The results of this study showed that the synthesized nanocomposite, along with UV radiation, is an effective and stable option for treating wastewater contaminated with emerging pollutants such as antibiotics. It can be scaled up for large-scale applications in environmental protection and to ensure compliance with effluent discharge standards.\u003c/p\u003e","manuscriptTitle":"Optimizing the removal of ciprofloxacin from aqueous solutions using an advanced oxidation process (TiO₂/Fe₃O₄/UVA) and evaluating toxicity via the biological reduction method of resazurin dye","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-17 17:50:51","doi":"10.21203/rs.3.rs-7727240/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-10-09T05:58:08+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"226970613006563891335469287910184902388","date":"2025-10-07T03:11:03+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-06T09:17:27+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-04T11:15:48+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-04T05:19:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"53315345854117135638678086931714357908","date":"2025-10-04T00:10:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"92301930102171642023577182720517810902","date":"2025-10-03T15:28:44+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"150042132103194925568157108431217576958","date":"2025-10-03T15:24:35+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"50787327493053940787889152692555996733","date":"2025-10-03T08:39:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"91781841874033781595282607093937081188","date":"2025-10-03T07:58:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"53181576154250333318588624239494113331","date":"2025-10-03T07:40:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"154676343416635863165294910944612443573","date":"2025-10-03T07:39:36+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"231699883524063297622671154294116536349","date":"2025-10-03T07:38:51+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-10-03T07:33:56+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-10-03T06:11:46+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-30T06:57:31+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-09-30T03:00:01+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-09-27T08:47:18+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"adcfe005-c1d6-42a3-af3a-2646ec248335","owner":[],"postedDate":"October 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":56001304,"name":"Physical sciences/Chemistry"},{"id":56001305,"name":"Earth and environmental sciences/Environmental sciences"}],"tags":[],"updatedAt":"2026-05-21T11:08:07+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-17 17:50:51","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7727240","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7727240","identity":"rs-7727240","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}