Sequential nitrification-denitrification process for nitrogenous, sulfurous and phenolic compounds removal in the same bioreactor

The kinetic and metabolic behavior of an aerobic granular sludge to nitrify, denitrify and nitrify-denitrify was evaluated in batch cultures. In nitrification control, ammonium, 4-methylphenol and sulfide were consumed efficiently (similar to 100%) and recovered as NO3-, CO2, S-0 and SO42-, respectively. In denitrification control, S-0 and nitrate were efficiently consumed and recovered as SO42- and N-2, respectively. Sequential nitrification-denitrification process was evaluated by applying oxic/anoxic conditions. Ammonium, 4-methylphenol and sulfide were oxidized to nitrate, CO2 and mainly S-0, respectively, under aerobic conditions. After that, anoxic conditions were established where S-0 reduced all nitrate to N-2, with molecular nitrogen yield (Y-N2) of 1.03 +/- 0.06 mg/mg NH4+-N consumed. This is the first study to show the capability of an aerobic granular sludge in simultaneous removal of ammonium, 4-methylphenol and sulfide by sequential nitrification-denitrification process in the same bioreactor. (C) 2013 Elsevier Ltd. All rights reserved.