PMID- 22748328
OWN - NLM
STAT- MEDLINE
DCOM- 20121030
LR  - 20131121
IS  - 1879-2448 (Electronic)
IS  - 0043-1354 (Linking)
VI  - 46
IP  - 14
DP  - 2012 Sep 15
TI  - Kinetics of nitrate and perchlorate removal and biofilm stratification in an ion 
      exchange membrane bioreactor.
PG  - 4556-68
LID - 10.1016/j.watres.2012.05.045 [doi]
AB  - The biological degradation of nitrate and perchlorate was investigated in an ion 
      exchange membrane bioreactor (IEMB) using a mixed anoxic microbial culture and 
      ethanol as the carbon source. In this process, a membrane-supported biofilm 
      reduces nitrate and perchlorate delivered through an anion exchange membrane from 
      a polluted water stream, containing 60 mg/L of NO(3)(-) and 100 mug/L of ClO(4)(-). Under 
      ammonia limiting conditions, the perchlorate reduction rate decreased by 10%, 
      whereas the nitrate reduction rate was unaffected. Though nitrate and perchlorate 
      accumulated in the bioreactor, their concentrations in the treated water (2.8 +/- 
      0.5 mg/L of NO(3)(-) and 7.0 +/- 0.8 mug/L of ClO(4)(-), respectively) were always below the 
      drinking water regulatory levels, due to Donnan dialysis control of the ionic 
      transport in the system. Kinetic parameters determined for the mixed microbial 
      culture in suspension showed that the nitrate reduction rate was 35 times higher 
      than the maximum perchlorate reduction rate. It was found that perchlorate 
      reduction was inhibited by nitrate, since after nitrate depletion perchlorate 
      reduction rate increased by 77%. The biofilm developed in the IEMB was 
      cryosectioned and the microbial population was analyzed by fluorescence in situ 
      hybridization (FISH). The results obtained seem to indicate that the kinetic 
      advantage of nitrate reduction favored accumulation of denitrifiers near the 
      membrane, whereas per(chlorate) reducing bacteria were mainly positioned at the 
      biofilm outer surface, contacting the biomedium. As a consequence of the biofilm 
      stratification, the reduction of perchlorate and nitrate occur sequentially in 
      space allowing for the removal of both ions in the IEMB.
CI  - Copyright (c) 2012 Elsevier Ltd. All rights reserved.
FAU - Ricardo, Ana R
AU  - Ricardo AR
AD  - REQUIMTE/CQFB, Department of Chemistry, FCT, Universidade Nova de Lisboa, Campus 
      de Caprarica, P-2829-516 Caparica, Portugal.
FAU - Carvalho, Gilda
AU  - Carvalho G
FAU - Velizarov, Svetlozar
AU  - Velizarov S
FAU - Crespo, Joao G
AU  - Crespo JG
FAU - Reis, Maria A M
AU  - Reis MA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120613
PL  - England
TA  - Water Res
JT  - Water research
JID - 0105072
RN  - 0 (Membranes, Artificial)
RN  - 0 (Nitrates)
RN  - 0 (Perchlorates)
RN  - 0 (Water Pollutants, Chemical)
RN  - VLA4NZX2P4 (perchlorate)
SB  - IM
MH  - Bacteria/growth & development/metabolism
MH  - Batch Cell Culture Techniques
MH  - Biodegradation, Environmental
MH  - *Biofilms
MH  - Biomass
MH  - Bioreactors/*microbiology
MH  - Denitrification
MH  - In Situ Hybridization, Fluorescence
MH  - Ion Exchange
MH  - Kinetics
MH  - Membranes, Artificial
MH  - Microbial Consortia
MH  - Nitrates/*isolation & purification
MH  - Perchlorates/*isolation & purification
MH  - Water Pollutants, Chemical/*isolation & purification
MH  - Water Purification/*instrumentation/*methods
EDAT- 2012/07/04 06:00
MHDA- 2012/10/31 06:00
CRDT- 2012/07/04 06:00
PHST- 2011/12/04 00:00 [received]
PHST- 2012/04/18 00:00 [revised]
PHST- 2012/05/22 00:00 [accepted]
PHST- 2012/07/04 06:00 [entrez]
PHST- 2012/07/04 06:00 [pubmed]
PHST- 2012/10/31 06:00 [medline]
AID - S0043-1354(12)00383-1 [pii]
AID - 10.1016/j.watres.2012.05.045 [doi]
PST - ppublish
SO  - Water Res. 2012 Sep 15;46(14):4556-68. doi: 10.1016/j.watres.2012.05.045. Epub 
      2012 Jun 13.