Investigation of Photo-Electrocoagulation Process Using an Optimized Cathode for Azo Dye Removal; Case Study on Direct Red 80

Investigation of Photo-Electrocoagulation Process Using an Optimized Cathode for Azo Dye Removal; Case Study on Direct Red 80 | 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 Investigation of Photo-Electrocoagulation Process Using an Optimized Cathode for Azo Dye Removal; Case Study on Direct Red 80 Samaneh Mozafari, Navid Nasirizadeh, Ali Sheibani, Mehdi Dehghani-zahedani, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7271495/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 15 You are reading this latest preprint version Abstract Background Anionic direct dyes, extensively used across various industries, are among the major sources of colored wastewater discharged into the environment annually. Such azo dyes are non-biodegradable and highly resistant to environmental factors. Due to their complex molecular structures, azo dyes are non-biodegradable and exhibit high resistance to conventional environmental treatments. This study aims to evaluate the efficiency of the photo-electrocoagulation (PEC) process using an optimized cathode for the removal of Direct Red 80 (DR80), a representative azo dye, from aqueous solutions. Materials and Methods The study was conducted in the laboratory setting, using a Photo-Electrocoagulation reactor with a volume of 500 ml, to analyze the effects of current density, electrolysis treatment time, and electrolyte concentration variables on the removal efficiency variable. This was conducted using the design of experiments (DOE) methodology and the Design-Expert software. In a later stage, the impacts of dye density and pH on removal efficiency were also investigated. Findings: The results demonstrated that increased current density, electrolysis time, and electrolyte concentration significantly enhanced dye removal efficiency. Under optimal conditions including current density of 296 mA/cm², electrolysis time of 10 minutes, and electrolyte concentration of 720 mg/L, a maximum removal efficiency of 98.21% was achieved. Conclusion An increase in dye density leads to a decrease in removal efficiency. Meanwhile, the removal efficiency increases upon a decrease in the level of pH. The highest amount of removal is achievable at a pH value of less than 4, indicating an acidic solution. Thus, the photo-electrocoagulation process is an effective method for the treatment of colored wastewater. Physical sciences/Chemistry Earth and environmental sciences/Environmental sciences Physical sciences/Materials science Photo-Electrocoagulation Optimized Cathode Azo Dye Removal Direct Red 80 Advanced Oxidation Processes (AOPs) Wastewater Treatment Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 24 Mar, 2026 Reviews received at journal 17 Mar, 2026 Reviewers agreed at journal 15 Mar, 2026 Reviewers agreed at journal 13 Mar, 2026 Reviews received at journal 01 Jan, 2026 Reviews received at journal 21 Dec, 2025 Reviewers agreed at journal 19 Dec, 2025 Reviewers agreed at journal 19 Dec, 2025 Reviews received at journal 09 Oct, 2025 Reviewers agreed at journal 12 Sep, 2025 Reviewers invited by journal 10 Sep, 2025 Editor assigned by journal 09 Sep, 2025 Editor invited by journal 09 Sep, 2025 Submission checks completed at journal 25 Aug, 2025 First submitted to journal 21 Aug, 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. 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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-7271495","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":515408244,"identity":"a1f8c2bf-851c-494b-b72a-eb5f13fbfd4a","order_by":0,"name":"Samaneh Mozafari","email":"","orcid":"","institution":"Islamic Azad University","correspondingAuthor":false,"prefix":"","firstName":"Samaneh","middleName":"","lastName":"Mozafari","suffix":""},{"id":515408245,"identity":"a0912ef6-090f-428e-a793-19c0b17d1674","order_by":1,"name":"Navid Nasirizadeh","email":"","orcid":"","institution":"Islamic Azad University","correspondingAuthor":false,"prefix":"","firstName":"Navid","middleName":"","lastName":"Nasirizadeh","suffix":""},{"id":515408246,"identity":"cc274848-470e-42be-a115-ead43e1d6c40","order_by":2,"name":"Ali Sheibani","email":"","orcid":"","institution":"Islamic Azad University","correspondingAuthor":false,"prefix":"","firstName":"Ali","middleName":"","lastName":"Sheibani","suffix":""},{"id":515408247,"identity":"a6fafd8b-6c08-49cc-8e31-f797af096f92","order_by":3,"name":"Mehdi Dehghani-zahedani","email":"","orcid":"","institution":"Islamic Azad University","correspondingAuthor":false,"prefix":"","firstName":"Mehdi","middleName":"","lastName":"Dehghani-zahedani","suffix":""},{"id":515408248,"identity":"61b4f50e-c2ca-4d60-8e27-2193a7bf9bc4","order_by":4,"name":"Reza Ali Fallahzadeh","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8ElEQVRIiWNgGAWjYBAC9gbmxgOMDUDWAR4Ggw8MDAkEtfAA1cO1FM4gWctnHqK0sB9sOPBzR5083/Heg5tt2+zy+NkbGD98zMGjhSex4WDvGTbDmWfOJRvntiUXS/YcYJacuQ23FnuGxIYDvG08jBtu5JgBtTAnbriRwMbMi0cLD//DhoN/2yTsN9x/Y/7bsq2eCC0SiQ2HedsMgCp5DIwZ2w4To+Vhw2HZtoTkmWdyDAx7zh1PnNlzsBmvX3j4kw8+fNtWZ9t3/IyBwY+y6sR+9uaDHz7i0YIKGNnAZAOx6kHgDymKR8EoGAWjYKQAACddXc7THl5FAAAAAElFTkSuQmCC","orcid":"","institution":"Shahid Sadoughi University of Medical Sciences","correspondingAuthor":true,"prefix":"","firstName":"Reza","middleName":"Ali","lastName":"Fallahzadeh","suffix":""}],"badges":[],"createdAt":"2025-08-01 13:08:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7271495/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7271495/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":91557285,"identity":"e89a0416-5451-4bc3-b34e-37a1bed28688","added_by":"auto","created_at":"2025-09-17 17:46:59","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":652299,"visible":true,"origin":"","legend":"","description":"","filename":"electrocoagulation.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7271495/v1_covered_eba25334-fb18-4837-8c18-3a785fe8e1ea.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Investigation of Photo-Electrocoagulation Process Using an Optimized Cathode for Azo Dye Removal; Case Study on Direct Red 80","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"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},"keywords":"Photo-Electrocoagulation, Optimized Cathode, Azo Dye Removal, Direct Red 80, Advanced Oxidation Processes (AOPs), Wastewater Treatment","lastPublishedDoi":"10.21203/rs.3.rs-7271495/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7271495/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eAnionic direct dyes, extensively used across various industries, are among the major sources of colored wastewater discharged into the environment annually. Such azo dyes are non-biodegradable and highly resistant to environmental factors. Due to their complex molecular structures, azo dyes are non-biodegradable and exhibit high resistance to conventional environmental treatments. This study aims to evaluate the efficiency of the photo-electrocoagulation (PEC) process using an optimized cathode for the removal of Direct Red 80 (DR80), a representative azo dye, from aqueous solutions.\u003c/p\u003e\u003ch2\u003eMaterials and Methods\u003c/h2\u003e\u003cp\u003eThe study was conducted in the laboratory setting, using a Photo-Electrocoagulation reactor with a volume of 500 ml, to analyze the effects of current density, electrolysis treatment time, and electrolyte concentration variables on the removal efficiency variable. This was conducted using the design of experiments (DOE) methodology and the Design-Expert software. In a later stage, the impacts of dye density and pH on removal efficiency were also investigated.\u003c/p\u003e\u003ch2\u003eFindings:\u003c/h2\u003e\u003cp\u003eThe results demonstrated that increased current density, electrolysis time, and electrolyte concentration significantly enhanced dye removal efficiency. Under optimal conditions including current density of 296 mA/cm\u0026sup2;, electrolysis time of 10 minutes, and electrolyte concentration of 720 mg/L, a maximum removal efficiency of 98.21% was achieved.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eAn increase in dye density leads to a decrease in removal efficiency. Meanwhile, the removal efficiency increases upon a decrease in the level of pH. The highest amount of removal is achievable at a pH value of less than 4, indicating an acidic solution. Thus, the photo-electrocoagulation process is an effective method for the treatment of colored wastewater.\u003c/p\u003e","manuscriptTitle":"Investigation of Photo-Electrocoagulation Process Using an Optimized Cathode for Azo Dye Removal; Case Study on Direct Red 80","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-17 17:14:54","doi":"10.21203/rs.3.rs-7271495/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-24T06:57:50+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-17T08:29:18+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"54565046283443393461572227755032475617","date":"2026-03-15T17:00:39+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"328437399809388378580640747154728966048","date":"2026-03-13T15:16:15+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-01T19:06:06+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-21T21:30:41+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"260963273277514011875534827331508728217","date":"2025-12-19T20:51:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"6400662984397841277346924505007264667","date":"2025-12-19T14:08:58+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-09T08:33:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"255059176556083242779380812739986697633","date":"2025-09-12T15:20:35+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-10T14:13:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-09-09T16:52:48+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-09-09T15:52:55+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-25T06:00:09+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-08-21T08:44:20+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":"b00dc7ed-2e0f-4dd7-abd3-86ffee6f2771","owner":[],"postedDate":"September 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[{"id":54748635,"name":"Physical sciences/Chemistry"},{"id":54748636,"name":"Earth and environmental sciences/Environmental sciences"},{"id":54748637,"name":"Physical sciences/Materials science"}],"tags":[],"updatedAt":"2026-03-24T07:08:49+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-17 17:14:54","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7271495","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7271495","identity":"rs-7271495","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}