Kinetics of nitrate and perchlorate removal and biofilm stratification in an ion exchange membrane bioreactor

The presence of anionic micropollutants, such as bromate, perchlorate and nitrate, in drinking water supplies represents a risk for public health. This work evaluates the applicability of the ion exchange membrane bioreactor (IEMB) concept for their removal. The IEMB concept combines the transport of anionic pollutants, through a dense mono-anion permselective membrane, with their simultaneous biodegradation to harmless products by a suitable microbial culture in a separated biocompartment. The transport of the pollutant counter-ions (anions) is governed by the Donnan equilibrium principle and, therefore, it is possible to enhance it by using a more concentrated driving counter-ion (e.g. chloride) added to the biocompartment. The IEMB process proved to selectively remove nitrate and perchlorate to concentrations below the recommended levels of 4 ppb for ClO4− and 25 ppm of NO3−, from a model polluted stream containing 100 ppb of ClO4− and 60 ppm of NO3−. Transport studies, made under Donnan dialysis conditions, showed bromate fluxes comparable to those obtained for nitrate under similar experimental conditions. However, the rate of biological reduction of bromate was about one order of magnitude slower than that of nitrate.

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Mercury removal from water streams through the ion exchange membrane bioreactor concept

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2013.10.067 ◽

2014 ◽

Vol 264 ◽

pp. 65-70 ◽

Cited By ~ 75

Author(s):

Adrian Oehmen ◽

Dario Vergel ◽

Joana Fradinho ◽

Maria A.M. Reis ◽

João G. Crespo ◽

...

Keyword(s):

Ion Exchange ◽

Membrane Bioreactor ◽

Ion Exchange Membrane ◽

Mercury Removal ◽

Exchange Membrane

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Ion exchange membrane bioreactor for treating groundwater contaminated with high perchlorate concentrations

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2013.10.050 ◽

2014 ◽

Vol 264 ◽

pp. 552-559 ◽

Cited By ~ 24

Author(s):

Shalom Fox ◽

Yoram Oren ◽

Zeev Ronen ◽

Jack Gilron

Keyword(s):

Ion Exchange ◽

Membrane Bioreactor ◽

Ion Exchange Membrane ◽

Exchange Membrane

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Multivariate analysis of the transport in an Ion Exchange Membrane Bioreactor for removal of anionic micropollutants from drinking water

Water Science & Technology ◽

10.2166/wst.2011.446 ◽

2011 ◽

Vol 63 (10) ◽

pp. 2207-2212

Author(s):

A. R. Ricardo ◽

S. Velizarov ◽

J. G. Crespo ◽

M. A. M. Reis

Keyword(s):

Ion Exchange ◽

Membrane Bioreactor ◽

Transport Model ◽

Statistical Design ◽

Principal Component ◽

Ion Exchange Membrane ◽

Membrane Properties ◽

Experimental Conditions ◽

A Minor ◽

Exchange Membrane

The present study focuses on investigating the effects of biological compartment conditions on the transport of nitrate and perchlorate in an Ion Exchange Membrane Bioreactor (IEMB). In this hybrid process, the transport depends not only on the membrane properties but also on the biological compartment conditions. The experiments were planned according to the Plackett-Burman statistical design in order to cover a broader range of experimental conditions, under which a previously developed mechanistic transport model was not able to predict correctly the transport fluxes of the target pollutants. Using Principal Component Analysis, it was possible to identify not only the concentrations of target (nitrate and perchlorate) and of major driving counter-ion (chloride) but also those of some biomedium components (e.g. ammonia, ethanol and sulphate) as variables that affect the transport rate of micropollutants across the membrane. These conclusions are based on the loadings of the two first principal components that describe 84% of the data variance. The present study also revealed that the hydraulic retention time and the hydrodynamic conditions in the biocompartment have a minor contribution to the micropollutants transport. The results obtained are important for process optimization purposes.

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