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

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Hui-Wen Lin
  • Caroline Kustermans
  • Eleni Vaiopoulou
  • Antonin Prévoteau
  • Korneel Rabaey
  • Ilje Pikaar

Detail(s)

Original languageEnglish
Pages (from-to)114-120
Journal / PublicationWater Research
Volume118
Publication statusPublished - 2017
Externally publishedYes

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. © 2017

Research Area(s)

  • In-situ chemical generation, Iron, Precipitation, Sewage, Sewer corrosion, Sulfide abatement

Bibliographic Note

Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to lbscholars@cityu.edu.hk.

Citation Format(s)

Electrochemical oxidation of iron and alkalinity generation for efficient sulfide control in sewers. / Lin, Hui-Wen; Kustermans, Caroline; Vaiopoulou, Eleni et al.
In: Water Research, Vol. 118, 2017, p. 114-120.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review