Enhancement of phosphorus removal with near-neutral pH utilizing steel and ferronickel slags for application of constructed wetlands

Jong Hwan Park, Seong Heon Kim, Ronald D. Delaune, Byung Hwa Kang, Se Won Kang, Ju Sik Cho, Yong Sik Ok, Dong Cheol Seo

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15 Citations (Scopus)


The objective of this study was to enhance phosphorus (P) removal while achieving near-neutral pH in aqueous solution utilizing steel slags (Blast furnace slag, BFS; Basic oxygen furnace slag-air cooling, BOFS-A; Basic oxygen furnace slag-rapid cooling, BOFS-R) and ferronickel slag (FNS) for application to constructed wetlands (CWs). The maximum P adsorption capacities (mg kg−1) of the slags were in the order BOFS-R (3233) > BOFS-A (2320) ≫ BFS (607) > FNS (260) based on the Langmuir adsorption isotherm. The pH of the slags were in the following order: BOFS-R (11.9) > BOFS-A (9.0) ≫ BFS (8.9) > FNS (7.5). The basic oxygen furnace slags had the highest P adsorption capacity, while the ferronickel slag had the lowest pH among the tested slags. To achieve high P removal efficiency with near-neutral pH, the BOF slags and ferronickel slag (BOFS-A + FNS and BOFS-R + FNS) were mixed in batch experiments. To achieve effective P removal with near-neutral pH utilizing steel and ferronickel slags, the optimum conditions were found to be the ratio of BOFS-R:FNS of 7:3. Therefore, when mixed slags at the BOFS-R:FNS ratio of 7:3 were applied to CWs, they could achieve high P removal efficiency and near-neutral pH for meeting the acceptable drinking water quality discharge standard.

Original languageEnglish
Pages (from-to)612-621
Number of pages10
JournalEcological Engineering
Publication statusPublished - 2016 Oct 1
Externally publishedYes



  • Basic oxygen furnace slag-air cooling (BOFS-A)
  • Basic oxygen furnace slag-rapid cooling (BOFS-R)
  • Blast furnace slag (BFS)
  • Ferronickel slag (FNS)
  • Freundlich isotherm
  • Langmuir isotherm
  • Phosphorus adsorption

ASJC Scopus subject areas

  • Environmental Engineering
  • Nature and Landscape Conservation
  • Management, Monitoring, Policy and Law

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