Modification of Streeter-Phelps Model for Dissolved Oxygen Concentration in a River: Incorporating Extended Sources and Sinks

Modification of Streeter-Phelps Model for Dissolved Oxygen Concentration in a River: Incorporating Extended Sources and Sinks | 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 Modification of Streeter-Phelps Model for Dissolved Oxygen Concentration in a River: Incorporating Extended Sources and Sinks Michael Okwudili Egbebike, Celestine Akaolisa Ezeagu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7151509/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 Dissolved Oxygen (DO) is a critical parameter reflecting the health and sustainability of aquatic ecosystems. The classical Streeter–Phelps model accounts primarily for oxygen dynamics governed by atmospheric reaeration and carbonaceous biochemical oxygen demand (CBOD). However, actual river systems experience more complex interactions involving additional oxygen sources and sinks, including nitrogenous biochemical oxygen demand (NBOD), sediment oxygen demand (SOD), photosynthetic oxygen production, and ecosystem respiration. This study extends and modifies the Streeter–Phelps model to account for these omitted processes. The modified model presents a comprehensive approach by deriving deficit expressions for each contributing factor, using standard techniques such as integrating factors and boundary condition application. A case study was conducted using Mamu River in Anambra State of Nigeria, with field measurements collected and used to calibrate the model. The result is a combined equation for total DO deficit that better reflects the physical, chemical, and biological interactions in natural water systems, validating its superiority over the classical model. Dissolved oxygen biochemical oxygen demand Streeter-Phelps model photosynthesis water quality modeling aquatic ecosystems 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. 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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-7151509","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":500215228,"identity":"c10c59bf-f4b6-4ca4-be80-4f01c03cedb3","order_by":0,"name":"Michael Okwudili Egbebike","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABFUlEQVRIie2RsWrDMBCGTwguixSvMqb4CQoOAdMhNH2UiEBGL4YuhWIwXJc8QkNeod082gTSxXQuZEn2BpKhpSVDK2cMEWm3QvVNv4770B0H4HD8VVgGAxTAlgAKTAAQP1R49DvFdKHav04p53cZW70VvaQtZvMbWVz026JkyzVBEl4dV+K65N2zepSipNFC1oqjzHhnQpB2SovyMsDAp5kmT8QLSQrRAwwkgX7MrEpr59OXUbz31CjCKK3dCQXZlkpNcozcKMoM1gTQU8v6cV3lAauHKYp515+QilBUuX//rPSDTXnKq+1ncZmE4+Fqs6bbvgnV5vW6p6eWwZqjcHFYgeamUWlTTMvH0XJo/cXhcDj+Gd9nb1OJn4DuNwAAAABJRU5ErkJggg==","orcid":"","institution":"Nnamdi Azikiwe University","correspondingAuthor":true,"prefix":"","firstName":"Michael","middleName":"Okwudili","lastName":"Egbebike","suffix":""},{"id":500215229,"identity":"bc1c99a5-434b-414f-89a0-1b2a36e911f6","order_by":1,"name":"Celestine Akaolisa Ezeagu","email":"","orcid":"","institution":"Nnamdi Azikiwe University","correspondingAuthor":false,"prefix":"","firstName":"Celestine","middleName":"Akaolisa","lastName":"Ezeagu","suffix":""}],"badges":[],"createdAt":"2025-07-17 17:53:20","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7151509/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7151509/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":94824763,"identity":"afe57815-df97-4d45-a1b5-8fdcfe7c144a","added_by":"auto","created_at":"2025-10-31 06:49:17","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":603019,"visible":true,"origin":"","legend":"","description":"","filename":"Review2RevStreeterPhelpsModifiedPaperMamuRiverFinal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7151509/v1_covered_e326087f-512b-41f2-9fb9-dde2784f8f0a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Modification of Streeter-Phelps Model for Dissolved Oxygen Concentration in a River: Incorporating Extended Sources and Sinks","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"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},"keywords":"Dissolved oxygen, biochemical oxygen demand, Streeter-Phelps model, photosynthesis, water quality modeling, aquatic ecosystems","lastPublishedDoi":"10.21203/rs.3.rs-7151509/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7151509/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eDissolved Oxygen (DO) is a critical parameter reflecting the health and sustainability of aquatic ecosystems. 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