Denitrification of drinking water by the association of an electrodialysis process and a membrane bioreactor: feasibility and application

• Published in: Desalination Vol. 139; no. 1-3; pp. 199 - 205
• Main Authors: Wisniewski, C., Persin, F., Cherif, T., Sandeaux, R., Grasmick, A., Gavach, C.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 20.09.2001; Elsevier
• Subjects: Applied sciences; Chemical Sciences; Denitrification; Drinking water; Drinking water and swimming-pool water. Desalination; Electrodialysis; Exact sciences and technology; Hybrid process; Membrane bioreactor; Pollution; Water treatment and pollution; France; Europe; Denitrification; Membrane bioreactor; Drinking water; Hybrid process; Electrodialysis; Biodegradation; Drinking water treatment; Combined process; Nitrates; Membrane separation; Membrane reactor; Bioreactor; Water quality; Performance; Nitrogen Compounds; Ground water
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/S0011-9164(01)00311-3

A hybrid process combining electrodialysis and a membrane bioreactor was investigated to treat ground waters with excessive nitrate concentrations. Electrodialysis (ED) allowed the nitrate separation producing, on one hand, partially demineralized waters whose ion concentrations were in agreement with the norm, and on the other hand, brines that were treated by a membrane bioreactor. Experiments performed at laboratory scale with synthetic solutions and pre-industrial scale to treat a ground water contaminated by nitrates showed high efficiency of the hybrid process. The nitrate concentration of the treated water remained below the acceptable value (50 mg/l−1) and even below the recommended value (25 mg/l−1) for drinking water. Moreover, the ED treatment induced a softening of the treated water. The biological denitrification allowed the almost total removal of nitrates (99%) with kinetics close to 0.3kgNNO3/kg MVS/d and a limited sludge production of 0.5 gV.S.S./gNNO3.