Electrochemical oxidation of iron and alkalinity generation for efficient sulfide control in sewers

Lin, Hui-Wen, Kustermans, Caroline, Vaiopoulou, Eleni, Prevoteau, Antonin, Rabaey, Korneel, Yuan, Zhiguo and Pikaar, Ilje (2017) Electrochemical oxidation of iron and alkalinity generation for efficient sulfide control in sewers. Water Research, 118 114-120. doi:10.1016/j.watres.2017.02.069


Author Lin, Hui-Wen
Kustermans, Caroline
Vaiopoulou, Eleni
Prevoteau, Antonin
Rabaey, Korneel
Yuan, Zhiguo
Pikaar, Ilje
Title Electrochemical oxidation of iron and alkalinity generation for efficient sulfide control in sewers
Journal name Water Research   Check publisher's open access policy
ISSN 1879-2448
0043-1354
Publication date 2017-07-01
Sub-type Article (original research)
DOI 10.1016/j.watres.2017.02.069
Open Access Status Not yet assessed
Volume 118
Start page 114
End page 120
Total pages 7
Place of publication London, United Kingdom
Publisher I W A Publishing
Language eng
Abstract The addition of iron salts is one of the most commonly used dosing strategies for sulfide control in sewers. However, iron salts decrease the sewage pH which not only reduces the effectiveness of sulfide precipitation but also enhances the release of residual sulfide to the sewer atmosphere. Equally important, concentrated iron salt solutions are corrosive and their frequent transport, handling, and on-site storage often come with Occupational Health and Safety (OH&S) concerns. Here, we experimentally demonstrated a novel sulfide control approach using electrochemical systems with parallel placed iron electrodes. This enabled combining anodic dissolved iron species release with cathodic hydroxyl anion production, which alleviates all the aforementioned concerns. A long-term experiment was successfully carried out achieving an average sulfide removal efficiency of 95.4 ± 4.4% at low voltage input of 2.90 ± 0.54 V over the course of 8 weeks. This electrochemical method was demonstrated to successfully achieve efficient sulfide control. In addition, it increases the sewage pH, thereby overcoming the drawbacks associated with the pH decrease in the case of conventional iron salt dosing. Ferrous ions were produced at an overall coulombic efficiency (CE) of 98.2 ± 1.2%, whereas oxygen evolution and direct sulfide oxidation were not observed. Short-term experiments showed that increasing either inter-electrode gap or current density increased the cell voltage associated with the increase in the ohmic drop of the system. Overall, this study highlights the practical potential of in-situ generation of dissolved iron species and simultaneous hydroxyl anion generation for efficient sulfide control in sewers.
Keyword In-situ chemical generation
Iron
Precipitation
Sewage
Sewer corrosion
Sulfide abatement
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Civil Engineering Publications
HERDC Pre-Audit
Advanced Water Management Centre Publications
 
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