Performance of nitrate-dependent anaerobic ferrous oxidizing (NAFO) process: a novel prospective technology for autotrophic denitrification

Bioresour Technol. 2015 Mar:179:543-548. doi: 10.1016/j.biortech.2014.12.036. Epub 2014 Dec 18.

Abstract

Nitrate-dependent anaerobic ferrous oxidizing (NAFO) is a valuable biological process, which utilizes ferrous iron to convert nitrate into nitrogen gas, removing nitrogen from wastewater. In this work, the performance of NAFO process was investigated as a nitrate removal technology. The results showed that NAFO system was feasible for autotrophic denitrification. The volumetric loading rate (VLR) and volumetric removal rate (VRR) under steady state were 0.159±0.01 kg-N/(m(3) d) and 0.073±0.01 kg-N/(m(3) d), respectively. In NAFO system, the effluent pH was suggested as an indicator which demonstrated a good correlation with nitrogen removal. The nitrate concentration was preferred to be less than 130 mg-N/L. Organic matters had little influence on NAFO performance. Abundant iron compounds were revealed to accumulate in NAFO sludge with peak value of 51.73% (wt), and they could be recycled for phosphorus removal, with capacity of 16.57 mg-P/g VS and removal rate of 94.77±2.97%, respectively.

Keywords: Autotrophic denitrification; NAFO; Operation conditions; Process mechanism; Working performance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaerobiosis
  • Autotrophic Processes*
  • Biotechnology / methods*
  • Denitrification*
  • Hydrogen-Ion Concentration
  • Iron / metabolism*
  • Nitrates / chemistry*
  • Nitrates / isolation & purification
  • Organic Chemicals / isolation & purification
  • Oxidation-Reduction
  • Phosphorus / isolation & purification
  • Sewage / chemistry
  • Volatilization
  • Waste Disposal, Fluid

Substances

  • Nitrates
  • Organic Chemicals
  • Sewage
  • Phosphorus
  • Iron