Nitrogen polishing in a fully anoxic anammox MBBR treating mainstream nitritation-denitritation effluent.
As nitrogen discharge limits are becoming more stringent, short-cut nitrogen systems and tertiary nitrogen polishing steps are gaining popularity. For partial nitritation or nitritation-denitritation systems, anaerobic ammonia oxidation (anammox) polishing may be feasible to remove residual ammonia and nitrite from the effluent. Nitrogen polishing of mainstream nitritation-denitritation system effluent via anammox was studied at 25°C in a fully anoxic moving bed bioreactor (MBBR) (V = 0.45 m(3) ) over 385 days. Unlike other anammox based processes, a very fast startup of anammox MBBR was demonstrated, despite nitrite limited feeding conditions (influent nitrite = 0.7 ± 0.59 mgN/L, ammonia = 6.13 ± 2.86 mgN/L, nitrate = 3.41 ± 1.92 mgN/L). The nitrogen removal performance was very stable within a wide range of nitrogen inputs. Anammox bacteria (AMX) activity up to 1 gN/m(2) /d was observed which is comparable to other biofilm-based systems. It is generally believed that nitrate production limits nitrogen removal through AMX metabolism. However, in this study, anammox MBBR demonstrated ammonia, nitrite, and nitrate removal at limited chemical oxygen demand (COD) availability. AMX and heterotrophs contributed to 0.68 ± 0.17 and 0.32 ± 0.17 of TIN removal, respectively. It was speculated that nitrogen removal might be aided by denitratation which could be due to heterotrophs or the recently discovered ability for AMX to use short-chain fatty acids to reduce nitrate to nitrite. This study demonstrates the feasibility of anammox nitrogen polishing in an MBBR is possible for nitritation-denitration systems.
Brown and Caldwell, 1600 Duke Street, Suite 310, Alexandria, VA, 22314. pregm001@gmail.com.
Pusker
P
Regmi
Hazen and Sawyer, P.C, New York, NY.
Becky
B
Holgate
Civil and Environment Engineering Department, Virginia Tech, Blacksburg, VA.
Mark W
MW
Miller
Department of Earth and Environmental Engineering, Columbia University, New York, NY.
Hongkeun
H
Park
Department of Earth and Environmental Engineering, Columbia University, New York, NY.
Kartik
K
Chandran
ARA Consult, Innsbruck, Austria.
Bernhard
B
Wett
DC Water Authority, Washington DC.
Sudhir
S
Murthy
Hampton Roads Sanitation District, Virginia Beach, VA.
Charles B
CB
Bott
D000641:Ammonia / Q000378:metabolism*; D000693:Anaerobiosis; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D019149:Bioreactors / Q000382:microbiology*; D009566:Nitrates / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D013696:Temperature; D018508:Water Purification
D009566:Nitrates; D009573:Nitrites; D000641:Ammonia; D009584:Nitrogen
MBBR; anammox; nitritation-denitritation; nitrogen polishing