Biological phosphorus and nitrogen removal in sequencing batch reactors: effects of cycle length, dissolved oxygen concentration and influent particulate matter

Water Sci Technol. 2013;68(5):982-90. doi: 10.2166/wst.2013.324.

Abstract

Removal of phosphorus (P) and nitrogen (N) from municipal wastewaters is required to mitigate eutrophication of receiving water bodies. While most treatment plants achieve good N removal using influent carbon (C), the use of influent C to facilitate enhanced biological phosphorus removal (EBPR) is poorly explored. A number of operational parameters can facilitate optimum use of influent C and this study investigated the effects of cycle length, dissolved oxygen (DO) concentration during aerobic period and influent solids on biological P and N removal in sequencing batch reactors (SRBs) using municipal wastewaters. Increasing cycle length from 3 to 6 h increased P removal efficiency, which was attributed to larger portion of N being removed via nitrite pathway and more biodegradable organic C becoming available for EBPR. Further increasing cycle length from 6 to 8 h decreased P removal efficiencies as the demand for biodegradable organic C for denitrification increased as a result of complete nitrification. Decreasing DO concentration in the aerobic period from 2 to 0.8 mg L(-1) increased P removal efficiency but decreased nitrification rates possibly due to oxygen limitation. Further, sedimented wastewater was proved to be a better influent stream than non-sedimented wastewater possibility due to the detrimental effect of particulate matter on biological nutrient removal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bioreactors / microbiology*
  • Nitrogen / isolation & purification
  • Nitrogen / metabolism*
  • Oxygen / chemistry
  • Particulate Matter / chemistry
  • Phosphorus / isolation & purification
  • Phosphorus / metabolism*
  • Water Pollutants, Chemical / isolation & purification
  • Water Pollutants, Chemical / metabolism*

Substances

  • Particulate Matter
  • Water Pollutants, Chemical
  • Phosphorus
  • Nitrogen
  • Oxygen