Effect of zero-valent iron activated sodium hypochlorite on sludge dewatering performance

Effect of zero-valent iron activated sodium hypochlorite on sludge dewatering performance | 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 Effect of zero-valent iron activated sodium hypochlorite on sludge dewatering performance TOU Junyi, JIANG Donghao, WANG Hao, GUO Shaodong This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8765093/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 Zero-valent iron (ZVI) activated sodium hypochlorite (NaClO) was used to condition sludge to improve sludge dewatering, and the mechanism of its effect on sludge cracking and dewatering performance was systematically investigated. The dewatering performance of sludge was measured by detecting capillary suction time (CST) and sludge specific resistance (SRF). The evolution patterns of substances such as ammonia nitrogen (NH₄-N), chemical oxygen demand (COD), soluble phosphorus (SRP), extracellular polymeric substances (EPS) (including soluble EPS (S-EPS), loosely bound EPS (LB-EPS), and tightly bound EPS (LB-EPS)), the study quantitatively and qualitatively analysed the migration patterns of organic substances within and outside sludge cells, clarifying the intrinsic connection between sludge disintegration and dewatering performance. The results showed that under the optimal treatment conditions (pH = 3 + Fe powder 75mg/gDS+ NaClO100mg/gDS) the CST of ZVI-NaClO treated sludge decreased from 192.7 s to 51.3 s; the SRF decreased from 2.05×10 9 S 2 /g to 1.35×10 9 S 2 /g; and NH 4 -N in the supernatant increased from 4.14 mg/L to 8.64 mg/L; DP increased from 0.47 ug/mL to 1.12 ug/mL; and COD increased from 960.5 mg/L to 2323.8 mg/L. Additionally, the synergistic effect of acidified ZVI-NaClO can oxidise and degrade organic matter in sludge, reducing glutamic acid and humic acid components in the three types of EPS in sludge. Therefore, the acidified ZVI-NaClO system can disrupt the structure of sludge flocs and efficiently degrade extracellular polymers (EPS), significantly improving sludge dewatering efficiency and providing a physical-chemical foundation for subsequent sludge reduction and resource utilization. sludge dewatering zero-valent iron sodium hypochlorite extracellular polymeric substances (EPS) free radical oxidation 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-8765093","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":615158379,"identity":"bee454e9-1831-490e-ad71-c58b42540740","order_by":0,"name":"TOU Junyi","email":"","orcid":"","institution":"School of Urban Construction,Wuhan University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"TOU","middleName":"","lastName":"Junyi","suffix":""},{"id":615158380,"identity":"c7965ffc-dc23-4445-a974-6cc2a639d104","order_by":1,"name":"JIANG Donghao","email":"","orcid":"","institution":"School of Urban Construction,Wuhan University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"JIANG","middleName":"","lastName":"Donghao","suffix":""},{"id":615158381,"identity":"b33b374e-552f-4e48-8807-6f208bd93f60","order_by":2,"name":"WANG Hao","email":"","orcid":"","institution":"School of Urban Construction,Wuhan University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"WANG","middleName":"","lastName":"Hao","suffix":""},{"id":615158382,"identity":"a09f4c67-6f3b-4710-aa33-b62edbdbc04f","order_by":3,"name":"GUO Shaodong","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA30lEQVRIiWNgGAWjYLACxgYgcQCIPxjYyJGmhXFGQZoxaVqYeT4cTiSoWj4i+QDjzx12cnzHew+/tjFgTmBgP3x0Az4thjfSEph5zyQbS545l2adY8CWx8CTlnYDr5YZOQbMjG3MiRtu5JgZ5xjwFDNI8JgR1ML4s60eosXCQCKxgZAWeYkcAwbetsMgLcaPGQwMCGsx4HkG9EvbcaBfzpgx9hgkGLMR8ot8OyjE2qqBIdZj/OHHn/9y/OyHj+G35QAD+w8om00CTOJTDralAcFm/kBI9SgYBaNgFIxMAAAh2UppeN4jvAAAAABJRU5ErkJggg==","orcid":"","institution":"School of Urban Construction,Wuhan University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"GUO","middleName":"","lastName":"Shaodong","suffix":""}],"badges":[],"createdAt":"2026-02-02 12:41:57","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8765093/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8765093/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106094791,"identity":"a4218bef-eb37-46e9-af2d-5115f076e499","added_by":"auto","created_at":"2026-04-03 11:43:15","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1282795,"visible":true,"origin":"","legend":"","description":"","filename":"ManuscriptFile.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8765093/v1_covered_eac13e1e-9f53-48df-ba59-9282615d1ae2.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effect of zero-valent iron activated sodium hypochlorite on sludge dewatering performance","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":"sludge dewatering, zero-valent iron, sodium hypochlorite, extracellular polymeric substances (EPS), free radical oxidation","lastPublishedDoi":"10.21203/rs.3.rs-8765093/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8765093/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eZero-valent iron (ZVI) activated sodium hypochlorite (NaClO) was used to condition sludge to improve sludge dewatering, and the mechanism of its effect on sludge cracking and dewatering performance was systematically investigated. The dewatering performance of sludge was measured by detecting capillary suction time (CST) and sludge specific resistance (SRF). The evolution patterns of substances such as ammonia nitrogen (NH₄-N), chemical oxygen demand (COD), soluble phosphorus (SRP), extracellular polymeric substances (EPS) (including soluble EPS (S-EPS), loosely bound EPS (LB-EPS), and tightly bound EPS (LB-EPS)), the study quantitatively and qualitatively analysed the migration patterns of organic substances within and outside sludge cells, clarifying the intrinsic connection between sludge disintegration and dewatering performance. The results showed that under the optimal treatment conditions (pH\u0026thinsp;=\u0026thinsp;3\u0026thinsp;+\u0026thinsp;Fe powder 75mg/gDS+ NaClO100mg/gDS) the CST of ZVI-NaClO treated sludge decreased from 192.7 s to 51.3 s; the SRF decreased from 2.05\u0026times;10\u003csup\u003e9\u003c/sup\u003e S\u003csup\u003e2\u003c/sup\u003e/g to 1.35\u0026times;10\u003csup\u003e9\u003c/sup\u003e S\u003csup\u003e2\u003c/sup\u003e/g; and NH\u003csub\u003e4\u003c/sub\u003e-N in the supernatant increased from 4.14 mg/L to 8.64 mg/L; DP increased from 0.47 ug/mL to 1.12 ug/mL; and COD increased from 960.5 mg/L to 2323.8 mg/L. Additionally, the synergistic effect of acidified ZVI-NaClO can oxidise and degrade organic matter in sludge, reducing glutamic acid and humic acid components in the three types of EPS in sludge. Therefore, the acidified ZVI-NaClO system can disrupt the structure of sludge flocs and efficiently degrade extracellular polymers (EPS), significantly improving sludge dewatering efficiency and providing a physical-chemical foundation for subsequent sludge reduction and resource utilization.\u003c/p\u003e","manuscriptTitle":"Effect of zero-valent iron activated sodium hypochlorite on sludge dewatering performance","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-03 00:01:39","doi":"10.21203/rs.3.rs-8765093/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","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}}],"origin":"","ownerIdentity":"c10d6935-4d78-4600-8b8b-818fbcb00dc3","owner":[],"postedDate":"April 3rd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-05T09:40:29+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-03 00:01:39","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8765093","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8765093","identity":"rs-8765093","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}