Full-scale investigation of in-situ iron and alkalinity generation for efficient sulfide control

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

20 Scopus Citations
View graph of relations

Author(s)

  • Ilje Pikaar
  • Markus Flugen
  • Hui-Wen Lin
  • Sirajus Salehin
  • Jiuling Li
  • Bogdan C. Donose
  • Paul G. Dennis
  • Lisa Bethke
  • Ian Johnson
  • Korneel Rabaey

Detail(s)

Original languageEnglish
Article number115032
Journal / PublicationWater Research
Volume167
Online published5 Sept 2019
Publication statusPublished - 15 Dec 2019
Externally publishedYes

Abstract

Hydrogen sulfide induced corrosion of concrete sewer pipes is a major issue for wastewater utilities globally. One of the most commonly used methods to combat hydrogen sulfide is the addition of ferric chloride. While a reliable and effective method, ferric chloride is acidic causing OH&S concerns as well as alkalinity consumption in sewage. This study investigates, under full-scale field conditions, an alternative method for sulfide control by in-situ electrochemical generation of iron ions using sacrificial iron electrodes. This method concomitantly produces alkalinity through cathodic OH generation, rather than consumption. The gaseous hydrogen sulfide concentrations at the discharge wet well of a real-life rising main (length: ~1 km in, diameter: 150 mm) decreased from 173 ppm to 43 ppm (90 percentile of peak values), when a current of 0.86 A/m3 of sewage was applied. The 90 percentile peak H2S value was further reduced to 6.6 ppm when the applied current was increased to 1.14 A/m3 sewage. Moreover, methane generation was almost completely inhibited from 25.3 ± 1.46 mg COD/L to 0.06 ± 0.04 mg COD/ L. The overall cell voltage remained constant throughout the experimental period clearly showing the stability of the process. Detailed characterization of the down-stream sewer pipe biofilm revealed the complexity of the iron chemistry as the in-situ produced iron ions undergo transformation into a variety of iron species. Overall, this study demonstrates that in-situ generation of iron and alkalinity is an effective alternative method for hydrogen sulfide control in sewers. © 2019 Published by Elsevier Ltd.

Research Area(s)

  • Electrochemistry, Hydrogen sulfide abatement, In-situ chemical generation, Real-life application, Sewer corrosion

Citation Format(s)

Full-scale investigation of in-situ iron and alkalinity generation for efficient sulfide control. / Pikaar, Ilje; Flugen, Markus; Lin, Hui-Wen et al.
In: Water Research, Vol. 167, 115032, 15.12.2019.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review