Removal of nitrate from water in a novel ion exchange membrane bioreactor

2002 ◽  
Vol 2 (2) ◽  
pp. 161-167 ◽  
Author(s):  
S. Velizarov ◽  
J.G. Crespo ◽  
M.A. Reis
Keyword(s):  
Ion Exchange ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Ion Exchange Membrane ◽  
Polluted Water ◽  
Water Conductivity ◽  
Water Stream ◽  
Permselective Membrane ◽  
Donnan Dialysis ◽  
Exchange Membrane

Biological denitrification in a novel ion exchange membrane reactor (IEMB) has been investigated. The polluted water was separated from the mixed denitrifying culture by a non-porous, mono-anion permselective membrane providing continuous exchange of nitrate for chloride added as a counter-ion to the biocompartment. A removal efficiency of 87% and a surface removal rate of about 1,400 mg NO3- m-2h-1 was achieved at a nitrate concentration of 150 mg NO3- L-1. The treated water stream was essentially free of ethanol, used as a carbon source, and NO2- ions whereas the original water conductivity was completely preserved due to very efficient Donnan exclusion of the cations present in the two solutions from the membrane used. The IEMB process showed higher removal efficiency and better nitrate selectivity compared to a Donnan dialysis process operated under similar conditions.

Removal of bromate, perchlorate and nitrate from drinking water in an ion exchange membrane bioreactor

2005 ◽  
Vol 5 (5) ◽  
pp. 9-14 ◽  
Author(s):  
C.T. Matos ◽  
S. Velizarov ◽  
J.G. Crespo ◽  
M.A.M. Reis
Keyword(s):  
Drinking Water ◽  
Ion Exchange ◽  
Membrane Bioreactor ◽  
Ion Exchange Membrane ◽  
Microbial Culture ◽  
Experimental Conditions ◽  
Biological Reduction ◽  
Permselective Membrane ◽  
Donnan Dialysis ◽  
Exchange Membrane

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.

Optimization of ion exchange membrane structures for Donnan dialysis

1982 ◽  
Vol 54 (7) ◽  
pp. 1153-1157 ◽  
Author(s):  
J. A. Cox ◽  
R. Gajek ◽  
G. R. Litwinski ◽  
J. Carnahan ◽  
W. Trochimczuk
Keyword(s):  
Ion Exchange ◽  
Ion Exchange Membrane ◽  
Membrane Structures ◽  
Donnan Dialysis ◽  
Exchange Membrane

scholarly journals Exploring the Function of Ion-Exchange Membrane in Membrane Capacitive Deionization via a Fully Coupled Two-Dimensional Process Model

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1312
Author(s):  
Xin Zhang ◽  
Danny Reible
Keyword(s):  
Ion Exchange ◽  
Removal Efficiency ◽  
Cycle Time ◽  
Process Model ◽  
Ion Exchange Membrane ◽  
Membrane Thickness ◽  
Two Dimensional ◽  
Capacitive Deionization ◽  
Exchange Membrane ◽  
Fully Coupled

In the arid west, the freshwater supply of many communities is limited, leading to increased interest in tapping brackish water resources. Although reverse osmosis is the most common technology to upgrade saline waters, there is also interest in developing and improving alternative technologies. Here we focus on membrane capacitive deionization (MCDI), which has attracted broad attention as a portable and energy-efficient desalination technology. In this study, a fully coupled two-dimensional MCDI process model capable of capturing transient ion transport and adsorption behaviors was developed to explore the function of the ion-exchange membrane (IEM) and detect MCDI influencing factors via sensitivity analysis. The IEM enhanced desalination by improving the counter-ions’ flux and increased adsorption in electrodes by encouraging retention of ions in electrode macropores. An optimized cycle time was proposed with maximal salt removal efficiency. The usage of the IEM, high applied voltage, and low flow rate were discovered to enhance this maximal salt removal efficiency. IEM properties including water uptake volume fraction, membrane thickness, and fixed charge density had a marginal impact on cycle time and salt removal efficiency within certain limits, while increasing cell length and electrode thickness and decreasing channel thickness and dispersivity significantly improved overall performance.

Ion exchange membrane adsorption in Donnan dialysis

2019 ◽  
Vol 226 ◽  
pp. 252-258 ◽  
Author(s):  
Anna Breytus ◽  
David Hasson ◽  
Raphael Semiat ◽  
Hilla Shemer
Keyword(s):  
Ion Exchange ◽  
Ion Exchange Membrane ◽  
Donnan Dialysis ◽  
Exchange Membrane

The role of ion exchange membrane in vanadium oxygen fuel cell

2021 ◽  
Vol 629 ◽  
pp. 119271
Author(s):  
Jiří Charvát ◽  
Petr Mazúr ◽  
Martin Paidar ◽  
Jaromír Pocedič ◽  
Jiří Vrána ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Ion Exchange ◽  
Ion Exchange Membrane ◽  
Exchange Membrane ◽  
Oxygen Fuel
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