Skip to main content
placeholder image

Improved sulfide mitigation in sewers through on-line control of ferrous salt dosing

Journal Article


Abstract


  • Water utilities worldwide spend annually billions of dollars to control sulfide-induced corrosion in sewers. Iron salts chemically oxidize and/or precipitate dissolved sulfide in sewage and are especially used in medium- and large-size sewers. Iron salt dosing rates are defined ad hoc, ignoring variation in sewage flows and sulfide levels. This often results in iron overdosing or poor sulfide control. Online dosing control can adjust the chemical dosing rates to current (and future) state of the sewer system, allowing high-precision, stable and cost-effective sulfide control. In this paper, we report a novel and robust online control strategy for the dosing of ferrous salt in sewers. The control considers the fluctuation of sewage flow, pH, sulfide levels and also the perturbation from rainfall. Sulfide production in the pipe is predicted using auto–regressive models (AR) based on current flow measurements, which in turn can be used to determine the dose of ferrous salt required for cost-effective sulfide control. Following comprehensive model-based assesment, the control was successfully validated and its effectiveness demonstrated in a 3-week field trial. The online control algorithm controlled sulfide below the target level (0.5 mg S/L) while reducing chemical dosing up to 30%.

Authors


  •   Ganigue, Ramon (external author)
  •   Jiang, Guangming
  •   Liu, Yiqi (external author)
  •   Sharma, Keshab (external author)
  •   Wang, Yue-Cong (external author)
  •   Gonzalez, Jose (external author)
  •   Nguyen, Tung (external author)
  •   Yuan, Zhiguo (external author)

Publication Date


  • 2018

Citation


  • Ganigue, R., Jiang, G., Liu, Y., Sharma, K., Wang, Y., Gonzalez, J., Nguyen, T. & Yuan, Z. (2018). Improved sulfide mitigation in sewers through on-line control of ferrous salt dosing. Water Research, 135 302-310.

Scopus Eid


  • 2-s2.0-85042375552

Number Of Pages


  • 8

Start Page


  • 302

End Page


  • 310

Volume


  • 135

Place Of Publication


  • United Kingdom

Abstract


  • Water utilities worldwide spend annually billions of dollars to control sulfide-induced corrosion in sewers. Iron salts chemically oxidize and/or precipitate dissolved sulfide in sewage and are especially used in medium- and large-size sewers. Iron salt dosing rates are defined ad hoc, ignoring variation in sewage flows and sulfide levels. This often results in iron overdosing or poor sulfide control. Online dosing control can adjust the chemical dosing rates to current (and future) state of the sewer system, allowing high-precision, stable and cost-effective sulfide control. In this paper, we report a novel and robust online control strategy for the dosing of ferrous salt in sewers. The control considers the fluctuation of sewage flow, pH, sulfide levels and also the perturbation from rainfall. Sulfide production in the pipe is predicted using auto–regressive models (AR) based on current flow measurements, which in turn can be used to determine the dose of ferrous salt required for cost-effective sulfide control. Following comprehensive model-based assesment, the control was successfully validated and its effectiveness demonstrated in a 3-week field trial. The online control algorithm controlled sulfide below the target level (0.5 mg S/L) while reducing chemical dosing up to 30%.

Authors


  •   Ganigue, Ramon (external author)
  •   Jiang, Guangming
  •   Liu, Yiqi (external author)
  •   Sharma, Keshab (external author)
  •   Wang, Yue-Cong (external author)
  •   Gonzalez, Jose (external author)
  •   Nguyen, Tung (external author)
  •   Yuan, Zhiguo (external author)

Publication Date


  • 2018

Citation


  • Ganigue, R., Jiang, G., Liu, Y., Sharma, K., Wang, Y., Gonzalez, J., Nguyen, T. & Yuan, Z. (2018). Improved sulfide mitigation in sewers through on-line control of ferrous salt dosing. Water Research, 135 302-310.

Scopus Eid


  • 2-s2.0-85042375552

Number Of Pages


  • 8

Start Page


  • 302

End Page


  • 310

Volume


  • 135

Place Of Publication


  • United Kingdom