Elimination of nitrate from drinking water by electrochemical membrane processes

摘要

The performance of three membrane processes (Donnan dialysis, electrodialysis, electrodeionization) using an ADS-Morgane anion-exchange membrane, was compared to remove nitrate from drinking water. The influence of concentration, current density and flow rate was studied with a 3.10~(-3) M nitrate solution to determine the best experimental conditions. Then the membrane processes were applied for the treatment of Montpellier drinking water where the nitrate concentration was increased up to a concentration of 80-100 ppm. In all cases the results showed extraction ratios higher than 80%. With the electrodialysis and electrodeionization techniques, the extraction rate of nitrate was faster than with Donnan dialysis, and a deionized water of high purity was obtained. A nitrate elimination ratio of 99% has been reached with electrodeionization.