Inorganic nitrogen transformations in the treatment of landfill leachate with a high ammonium load: A case study

Stephen Parkes*, Dianne F. Jolley, Stephen R. Wilson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

The inorganic nitrogen transformations occurring at a municipal waste leachate treatment facility were investigated. The treatment facility consisted of a collection well and an artificial wetland between two aeration ponds. The first aeration pond showed a decrease in ammonium (from 3480 (± 120) to 630(±90) mg · L-1), a reduction in inorganic nitrogen load (3480 to 1680 mg N · L-1), and an accumulation of nitrite (< 1.3 mg-N · L-1 in the collection well, to 1030 mg-N · L-1). Incomplete ammonium oxidation was presumably the result of the low concentration of carbonate alkalinity (∼2 mg · L-1), which may cause a limitation in the ammonium oxidation rate of nitrifiers. Low carbonate alkalinity levels may have been the result of stripping of CO2 from the first aeration pond at the high aeration rates and low pH. Various chemodenitrification mechanisms are discussed as the reason for the reduction in the inorganic nitrogen load, including; the reduction of nitrite by iron (II) (producing various forms of gaseous nitrogen); and reactions involving nitrous acid. It is suggested that the accumulation of nitrite may be the result of inhibition of nitrite oxidizers by nitrous acid and low temperatures. Relative to the first aeration pond, the speciation and concentration of inorganic nitrogen was stable in the wetlands and 2nd aeration pond. The limited denitrification in the wetlands most probably occurred due to low concentrations of organic carbon, and short retention times.

Original languageEnglish (US)
Pages (from-to)51-61
Number of pages11
JournalEnvironmental Monitoring and Assessment
Volume124
Issue number1-3
DOIs
StatePublished - Jan 1 2007

Keywords

  • Chemodenitrification
  • Landfill leachate
  • Nitrification
  • Nitrite accumulation
  • Nitrogen budget

ASJC Scopus subject areas

  • Environmental Science(all)
  • Environmental Chemistry

Fingerprint

Dive into the research topics of 'Inorganic nitrogen transformations in the treatment of landfill leachate with a high ammonium load: A case study'. Together they form a unique fingerprint.

Cite this