Enhancing sludge dewaterability and phosphate removal through a novel chemical dosing strategy using ferric chloride and hydrogen peroxide
© 2020 Water Environment Federation.
| Veröffentlicht in: | Water environment research : a research publication of the Water Environment Federation. - 1998. - 93(2021), 2 vom: 07. Feb., Seite 232-240 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2021
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| Zugriff auf das übergeordnete Werk: | Water environment research : a research publication of the Water Environment Federation |
| Schlagworte: | Journal Article dewatering ferrous oxidation improved cake solid contents phosphate removal Chlorides Ferric Compounds Phosphates Sewage Water mehr... |
| Zusammenfassung: | © 2020 Water Environment Federation. In this study, we replicated full-scale centrifuge dewatering utilized in water resource recovery facilities (WRRFs) by using the Higgins modified centrifuge technique and demonstrated that analogous cake solid content and centrate suspended solids were attainable while applying a lower polymer dosage. Furthermore, we demonstrated a dramatic reduction in the concentration of phosphate (P) in anaerobically digested sludge (ADS) under various reaction conditions. H2 O2 was employed to convert embedded iron in ADS, in the form of FeS, to Fe (II) and Fe (III), which subsequently reacted to precipitate phosphate compounds, dropping the in situ P concentration by nearly 50%. Adding ferric chloride (220 mg/L) in ADS enhanced the P-removal to more than 80%. Finally, simultaneous dosing of Fe and H2 O2 boosted P-removal efficiency to higher than 90%. The role of Fe in strengthening the flocs and increasing the dewaterability was also substantiated by demonstrating a 2% growth in the cake solid content when ADS was conditioned with Fe + H2 O2 preceding polymer treatment. The outcome of this work confirms that a deeper understanding of centrifuge operational parameters and physico-chemical properties of wastewater sludge would result in improved performance of municipal WRRFs. PRACTITIONER POINTS: Dosing hydrogen peroxide effectively converted iron embedded in sludge from Fe (II) to Fe (III). Simultaneous dosing of iron and hydrogen peroxide boosted P removal efficiency. The role of iron in strengthening flocs and enhancing dewaterability was observed, as it increased cake solid content in centrifuged sludge. An advanced bench-scale test protocol was employed to optimize polymer dose, simultaneously reducing polymer consumption while maximizing cake solid content and centrate quality |
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| Beschreibung: | Date Completed 03.02.2021 Date Revised 03.02.2021 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1554-7531 |
| DOI: | 10.1002/wer.1395 |