Gilmore, Kevin R.2; Terada, Akihiko1; Smets, Barth F.1; Love, Nancy G.3; Garland, Jay L.4
1 Department of Environmental Engineering, Technical University of Denmark2 Virginia Polytechnic Institute and State University3 University of Michigan4 Dynamac Corporation, Kennedy Space Center
This work describes the successful coupling of partial nitrification (nitritation) and anaerobic ammonium oxidation in a membrane-aerated biofilm reactor (MABR) with continuous aeration. Controlling the relative surface loadings of oxygen versus ammonium prevented complete nitrite oxidation and allowed anaerobic ammonium-oxidizing bacteria (AnaerAOB) to develop and be retained for > 250 days. Daily autotrophic nitrogen removal of 1.7 g N/m(2) (75% of influent N load) was achieved at an oxygen/nitrogen surface loading ratio of 2.2, with up to 85% of the influent N proceeding through AnaerAOB. During early nitritation, nitrogen oxide (NO(g), NO2(g), and N2O(g)) emissions comprised up to 10% of the removed influent nitrogen, but emissions disappeared after proliferation of AnaerAOB. Microbial communities were radially stratified, with aerobic ammonium-oxidizing bacteria (AerAOB) colonizing nearest to and AnaerAOB furthest from the membrane. Despite the presence of nitrite-oxidizing bacteria, this work demonstrated that these autotrophic processes can be successfully coupled in an MABR with continuous aeration, achieving the benefits of competitive specific N removal rates and the elimination of gaseous nitrogen oxide emissions.
Environmental Engineering Science, 2013, Vol 30, Issue 1, p. 38-45
autotrophic process; continuous aeration; microbial community; Microorganisms (Bacteria, Eubacteria, Microorganisms) - Bacteria  bacteria common bioindicator; ammonium 14798-03-9 oxidation; nitric oxide 10102-43-9; nitrite 14797-65-0 oxidation; nitrogen 7727-37-9 pollutant, water pollutant removal; nitrogen dioxide 10102-44-0; nitrogen oxide 11104-93-1; nitrous oxide 10024-97-2; oxygen 7782-44-7; 10060, Biochemistry studies - General; 31000, Physiology and biochemistry of bacteria; 37015, Public health - Air, water and soil pollution; 39008, Food microbiology - General and miscellaneous; membrane-aerated biofilm reactor MABR laboratory equipment; Bioprocess Engineering; Equipment Apparatus Devices and Instrumentation; Pollution Assessment Control and Management