The immobilized biological filter (IBF) using Fe(II) and Mn(II) as mixed electron donor were elaborated for nitrate removal in groundwater. The single factor experiments of strain SZ28 under the conditions of electron donor:electron acceptor ratio (1:2, 1.45:1, 3:1), Fe(II):Mn(II) ratio (1:9, 3:7, 5:5), the results demonstrated that the highest nitrate removal ratio of nitrate was 100%, 49.6% (Mn(II)) and 100% (Fe(II)) under the conditions of electron donor:electron acceptor ratio of 3:1, Fe(II):Mn(II) ratio of 5:5. Mn(II) and Fe(II) as electron donor was tested the effects on denitrification in the IBF reactor. The optimal conditions was obtained at electron donor:electron acceptor ratio of 2:1, hydraulic retention time of 12 h and Fe(II):Mn(II) ratio of 5:5 with the highest removal ratio of nitrate-N (100%), Mn(II) (50.25%) and Fe(II) (99.2%). Results suggested that the optimal condition obtained from IBF was feasible.
- autotrophic denitrification (AD)
- electron donor
- immobilized biological filter (IBF)
- First received 8 December 2016.
- Accepted in revised form 16 March 2017.
- © IWA Publishing 2017