Enriquecimento de bactérias anaeróbias oxidadoras de am？nia - anammox

anaerobic ammonium-oxidizing (anammox) bacteria were enriched from sludge collected at a conventional activated sludge system treating domestic wastewater of belo horizonte(mg), brazil, employing a sequencing batch reactor (sbr). after three months of cultivation, anammox activity was detected in the system by the consumption of stoichiometric amounts of no2- and nh4+. fluorescent in situ hybridization (fish) results revealed the presence of anammox bacteria (probably candidatus brocadia anammoxidans) and showed that they accounted for 53% of the total bacterial population (after 6 months of cultivation). the reactor performance during the seven months of operation showed a near perfect removal of nitrite, based on the influent no2--n concentration of 61-95 mg/l. the maximum ammonia removal efficiency was 95% from the influent n-nh4+ concentration of 55-82 mg/l.