Resumo

The anammox process to N- removal reduce costs with aeration and exogenous electron donor as compared to the nitrification-denitrification process. The purpose of the study was to search for the anammox bacteria presence in different samples by using the molecular technique in order to select appropriate seeding sludge for start-up of anammox enrichment reactors that can be used in the waste water treatment with high ammonium concentrations. Twenty three samples were collected from thirteen different systems treating domestic sewage (Center for Research and Training in Sanitation in the UFMG/COPASA) and industrial effluent (Gabriel Passos oil refinery -REGAP). DNA was extracted using Kit Mo Bio. To detect Anammox bacteria, PCRs were performed with primes for the amplification of 16SrRNA (Pla46f-Amx667r, Pla46f-Amx820r and Pla46f-Amx1240r) and hydrazine oxidoreductase-hzo genes (HzoF1/Ana hzo2R) from anammox organisms.Two anaerobic up-flow fixed-bed glass reactors are being used for anammox enrichment. The anammox diversity of these two selected sludges was investigated via DGGE (Pla46F/Amx368R-GC) and sequencing of DNA. Among the samples investigated, six showed positive results with all the primers tested. Positive results were obtained by using primers for the 16S rRNA gene, in almost all the samples investigated except for four samples. These results indicate that anammox process might be occurring in these domestic and industrial WWTP and these sludges could be used as inoculum for anammox enrichment reactors. The Anammox were enriched by using sludge samples from the wetlands and from the aerated lagoon (REGAP) as inoculum. All the sequences selected in the DGGE profiles these samples inoculated, were related to uncultured Planctomycetes bacterium clones, except for one related to Candidatus Brocadia caroliniensis strain. The presence and potential contribution of anammox bacteria in the constructed wetlands is important because it suggest a re-evaluation of the major fluxes in the compounds of nitrogen budget and regulation of the processes leading to losses of fixed nitrogen These experiments are in progress and anammox activity has been detected in the reactor inoculated with sludge from the lagoon (REGAP), and wetland constructed, after 9 months of operation, the average ammonia and nitrite removal efficiencies are 90% and 95%, respectively.