PVA-GEL BEADS AS A BIOMASS CARRIER FOR ANAEROBIC OXIDATION OF AMMONIUM IN A PACKED-BED REACTOR

Abstract

Continuous-flow experiments were conducted using PVA-gel beads as a biomass carrier in an anaerobic packed-bed reactor. With influent ammonium and nitrite concentrations gradually increased to 350 mg N l-1 each (total nitrogen, 700 mg N l-1), total-nitrogen removal rates of up to 80 mg N l-1 h-1 (ammonium removal, 40 mg N l-1 h-1) were demonstrated. By FISH analysis, the anammox bacteria were shown to form clusters with a peripheral association of Zoogloea related species. In addition, though the reactor had been well seeded with two known anammox strains differing on the genus level and originating from very different locations, after one year of operation, only the strain that had been discovered at the location of this study could be detected. 1.