PMID- 20227741
OWN - NLM
STAT- MEDLINE
DCOM- 20100813
LR  - 20100426
IS  - 1879-2448 (Electronic)
IS  - 0043-1354 (Linking)
VI  - 44
IP  - 9
DP  - 2010 May
TI  - Nitrifier characteristics in submerged membrane bioreactors under different 
      sludge retention times.
PG  - 2823-30
LID - 10.1016/j.watres.2010.02.021 [doi]
AB  - Three submerged membrane bioreactors (MBRs) were operated continuously for 230 
      days by feeding with synthetic inorganic wastewater (NH(4)(+)-N, 100 mg L(-1)) 
      under different solids retention times (SRTs. M(30d), 30 days; M(90d), 90 days; 
      M(infinite), no sludge purge) to examine the influence of SRT on nitrification 
      performance and microbial characteristics. All the reactors could oxidize 
      NH(4)(+)-N to NO(3)(-)-N effectively without accumulation of NO(2)(-)-N. M(30d) 
      with the shortest SRT showed significantly higher specific ammonium oxidizing 
      rate (SAOR, 0.22 kg NH(4)(+)-N kg(-1) MLSS day(-1)) and specific nitrate forming 
      rate (SNFR, 0.13 kg NO(3)(-)-N kg(-1) MLSS day(-1)) than the other two MBRs 
      (0.12-0.14 kg NO(3)(-)-N kg(-1) MLSS day(-1) and 0.042-0.068kg NO(3)(-)-N kg(-1) 
      MLSS day(-1), respectively). Short SRT led to low extracellular polymeric 
      substances (EPS) concentration and long operating cycle. The nitrite oxidizing 
      bacteria (NOB) ratios by both the fluorescence in situ hybridization (FISH) (3.6% 
      for M(30d) and 2.1-2.2% for M(90d) and M(infinite)) and MPN (1.4 x 10(7)cells 
      g(-1) MLSS for M(30d) and 6.2 x 10(5) and 2.7 x 10(4)cells g(-1) MLSS for M(90d) 
      and M(infinite)) analyses showed that M(30d) favored the accumulation of NOB, 
      which was in accordance with the SNFR result. However, the ammonia oxidizing 
      bacteria (AOB) ratios (3.5%, 3.2% and 4.9% for M(30d), M(90d) and M(infinite)) 
      were not in accordance with the SAOR result. PCR-DGGE, clone library and FISH 
      results showed that the fast-growing Nitrosomonas and Nitrobacter sp. were the 
      dominant AOB and NOB, respectively for M(30d), while considerable slow-growing 
      Nitrosospira and Nitrospira sp. existed in M(infinite), which might be an 
      important reason why M(infinite) had a low SAOR and SNFR.
CI  - Copyright (c) 2010 Elsevier Ltd. All rights reserved.
FAU - Yu, Tao
AU  - Yu T
AD  - State Key Laboratory of Environmental Aquatic Chemistry, Research Center for 
      Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, 
      Haidian District, Beijing, China.
FAU - Qi, Rong
AU  - Qi R
FAU - Li, Dong
AU  - Li D
FAU - Zhang, Yu
AU  - Zhang Y
FAU - Yang, Min
AU  - Yang M
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20100221
PL  - England
TA  - Water Res
JT  - Water research
JID - 0105072
RN  - 0 (Membranes, Artificial)
RN  - 0 (Nitrites)
RN  - 0 (Sewage)
SB  - IM
MH  - *Biodegradation, Environmental
MH  - Bioreactors/microbiology
MH  - Membranes, Artificial
MH  - Nitrites/*metabolism
MH  - Nitrobacter/metabolism
MH  - Nitrosomonas/metabolism
MH  - Refuse Disposal/methods
MH  - Sewage/*microbiology
MH  - Time Factors
MH  - Water Purification/methods
EDAT- 2010/03/17 06:00
MHDA- 2010/08/14 06:00
CRDT- 2010/03/16 06:00
PHST- 2009/10/28 00:00 [received]
PHST- 2010/02/03 00:00 [revised]
PHST- 2010/02/16 00:00 [accepted]
PHST- 2010/03/16 06:00 [entrez]
PHST- 2010/03/17 06:00 [pubmed]
PHST- 2010/08/14 06:00 [medline]
AID - S0043-1354(10)00142-9 [pii]
AID - 10.1016/j.watres.2010.02.021 [doi]
PST - ppublish
SO  - Water Res. 2010 May;44(9):2823-30. doi: 10.1016/j.watres.2010.02.021. Epub 2010 
      Feb 21.