Biostimulation of a marine anammox bacteria-dominated bioprocess by Co(II) to treat nitrogen-rich, saline wastewater.

The biostimulation of a marine anammox bacteria (MAB)-dominated bioprocess with Co(II) was studied in a sequencing batch reactor (SBR) treating nitrogen-rich saline wastewater at 15 degrees C. The low Co(II) load of 0.0015 kgCoji'ded,/(m3-d) had little effect on the removal of nitrogen. The nitrite removal rate (NRR), ammonia removal rate (ARR), and specific anammox activity (SAA) reached 0.73 kg/(m(3).d), 0.59 kg/(m(3).d), and 023 kw (kg.d), respectively, under the Co(II) load of 0.009 kgCo(added)(2+)(m(3)d). However, the loadings of Co(II) at 0.024-0.03 kgCoiLedl(m(3)-d) negatively affected the activity of MAB. Besides, the values of ANO2 (1.15-129) were lower than the theoretical ratio values (around 1.32) likely because of the marine commamox process. The removal of nitrogen from nitrogen-rich saline wastewater was achieved by the synergy between Candidaf us Scalindua (27.11%) and Candidatus Kuenenia (9.55%). The nitrogen removal with Co(II) addition could be well described by a modified Logistic model. (C) 2020 Elsevier B.V. All rights reserved.