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Large‐Scale Biological Nitrate and Ammonia Removal
Author(s) -
ROGALLA F.,
RAVARINI P.,
LARMINAT G. De,
COUTTELLE J.
Publication year - 1990
Publication title -
water and environment journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 37
eISSN - 1747-6593
pISSN - 1747-6585
DOI - 10.1111/j.1747-6593.1990.tb01400.x
Subject(s) - nitrate , environmental science , environmental chemistry , ammonia , anoxic waters , water treatment , nitrogen , environmental engineering , pilot plant , aeration , water quality , chemistry , activated carbon , raw water , nitrification , pulp and paper industry , ecology , engineering , biology , organic chemistry , adsorption
In order to treat water containing nitrogen in excess of the European Drinking Water guideline, an innovative large‐scale biological, nitrogen‐removal process has been used. After extensive pilot‐scale testing and a first full‐scale (80 m 3 /h) demonstration at Eragny (France), a 400 m 3 /h installation, serving about 50000 people, was built at Guernes‐Dennemont, near Paris. The raw water source is a combination of percolation from agricultural plains and river bank infiltration, and contains both nitrates and ammonia. The plant consists of two fixed‐bed biological reactors in series. An anoxic filter, using ethanol as a carbon source for heterotrophic bacteria, removes nitrates at filtration rates up to 10 m/h. The denitrified water is then polished on an aerated two‐layer filter, packed with activated carbon and sand. Excess carbon from the first stage, together with reduced nitrogen (ammonia and nitrates), is oxidized at this stage before ozonation of the water. Design data and operational performance are given for total nitrogen (NO 3 and NH,), total organic carbon (TOC) and chlorinated hydrocarbons. A specific dosing method for biodegradable carbon was developed to monitor the efficiency of the post‐treatment. Special attention was paid to (a) nitrate control through improved backwash, and (b) reducing the potential for bacterial contamination and aftergrowth in the distribution network.