CYCLOR - Nitrate-shunt: An alternative method of processing effluents with high nitrogen content
Presented by Degrémont / SUEZ Environnement
CONTEXT
In a water-treatment plant, anaerobic digestion reduces the organic proportion of sludge while reducing the quantities for disposal. This process increases the amount of nitrogen to be processed from 15 to 35%. It is then removed using nitrification in an aerobic environment and subsequently by anoxic denitrification.
This process consumes a lot of oxygen and carbonated reagents and also entails long holding times and high reservoir volumes.
INNOVATION
To comply with waste standards imposed by various water directives, a new technique has been developed to process effluents. It eliminates nitrogen via a nitrate-shunt process which both prevents nitrates from being produced and also reduces them by inhibiting nitrification. This technique is made even more efficient by the use of Degrémont's CYCLOR reactor. It works by separating supply and aerobic/anoxic (no oxygen) reactions. This new process has been patented jointly by Degrémont and SUEZ Environment.
RESULTS
This technique reduces consumption of oxygen and carbonated reagents and also restricts the amount of sludge produced. The environmental impact of nitrogen processing is reduced to approximately 40%. Moreover, using CYCLOR also reduces operating costs by 20% while investment is limited since he highest possible reservoir volumes are used. At present, the CYCLOR nitrateshunt reactor is in use at the Bilten wastewater processing station in Switzerland and an industrial prototype is in operation at the Creil station operated by Lyonnaise des Eaux. Many sites are likely to introduce the process, including for use with other types of effluents with high nitrogen content.
