ARS | Publication request: Isolation and culture of anammox bacteria adapted to livestock wastewater environments

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 4, 2007
Publication Date: November 4, 2007
Citation: Vanotti, M.B., Szogi, A.A. 2007. Isolation and culture of anammox bacteria adapted to livestock wastewater environments [abstract]. American Society of Agronomy Annual Meeting Abstracts, November 2-8, 2007, New Orleans, Louisiana. 2007 CDROM.

Technical Abstract: Research was conducted to develop process applications for anaerobic ammonium oxidation (anammox) bacteria acclimated to animal wastewater conditions using microbial immobilization techniques. In the anammox reaction, under anaerobic and autotrophic conditions, ammonium (NH4+) serves as the electron donor using equal molar amounts of (NO2-) as the electron acceptor resulting in production of harmless di-nitrogen (N2) gas. The anammox cultures were successfully established using continuous-flow unit processes, and biomass carriers seeded with sludges of manure origin. Laboratory bioreactors were seeded with the farm sludges after acclimation with nitrate solution to remove endogenous carbon. The bioreactors were operated in continuous flow and contained polyvinyl alcohol (PVA) hydrogel biomass carrier beads for immobilization and enrichment of the slow growth microorganisms. A distinct red biomass growth, which is typical of the Anammox planctomycete, developed in the reactors only when high nitrogen (300 mg N/L) and salt strength concentration was used in the synthetic enrichment medium. Under these conditions and protocol, it took about 100 days for the anammox reaction to develop from farm sludges obtained in NC swine farms. Removal of NO2- and NH4+ was simultaneous at the following stoichiometric ratios: NH4+ + 1.24 NO2- = 1.00 N2 + 0.24 NO3- In a second phase of the research, a pilot reactor was seeded directly with the anammox red sludge biomass produced before. As biomass carrier, the reactor used a polyester non-woven material coated with pyridinium type polymer to enhance retention of microorganisms. Removals of NO2- and NH4+ at typical ratios of the anammox reaction occurred from day 1 of operation. Nitrogen removal rate obtained was 0.9 kg N/m3/day, which is in the high range of industrial bio-treatment applications. These findings overall may lead to development of more economical treatment systems for livestock wastewater and other effluents containing high ammonia concentration.