Reactivation of Active-Sludge Biocatalysts after a their Long Storage and Startup of the DEAMOX Process
Recently, a so-called DEAMOX process, in which the ANAMMOX reaction (anaerobic oxidation of ammonium nitrogen by nitrite) is combined with denitratation (production of nitrite from nitrate) has been worked out in our laboratory in order to eliminate nitrogen contaminants from wastewater. Both above anaerobic stages were performed by the same sludhe biocatalyst. The results of reactivation of sludge biocatalysts after their long-time storage (5 months or 16 months) and a successful start-up of the DEAMOX process in two (S- and O-) modifications are represented. The S-DEAMOX was launched using the biocatalyst with the restored ANAMMOX activity of 20,1 mg N/gAB/day, and the total elimination of nitrogen from the reactor was 78% for 20 days. Time of the start-up of O-DEAMOX using the biocatalyst with the ANAMMOX activity equal to 6,1 mg N/gAB/day made up 30 days with the total value of eliminated nitrogen compounds reaching 87%. Two different electron donors, inorganic sulphide (for S-DEAMOX) and organic acetate (for O-DEAMOX), were used during the stage of the nitrite production from nitrate.