Bioresource Technology, Vol.179, 543-548, 2015
Performance of nitrate-dependent anaerobic ferrous oxidizing (NAFO) process: A novel prospective technology for autotrophic denitrification
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. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords:Autotrophic denitrification;NAFO;Working performance;Operation conditions;Process mechanism