Abstract
Pilot-scale tests were carried out for nitrogen removal from ammonium plant effluent using gel carriers on which anaerobic ammonium oxidation (anammox) sludge was immobilized. The nitrogen removal system was equipped with an anammox vessel of 5 m3 volume and the pretreatment processes were carried out for continuous feeding tests. The nitrogen removal in the anammox vessel could be started up within approximately 2 months of acclimation using ammonia synthetic plant effluent (ammonia wastewater) at 30°C. After that, stable nitrogen removal in the anammox vessel was confirmed at 16.1°C even though the influent was changed to another kind of wastewater based on urea. Moreover, nitrogen removal in the anammox vessel reached the designated denitrification rate within 3 days at 30°C after influent wastewater was returned to the original ammonia wastewater. Finally, the anammox vessel was operated using the ammonia wastewater at a low water temperature. The nitrogen conversion rate was stably observed 1.9 kg-N•m3•d-1 at 17.1°C. These results strongly suggest that this nitrogen removal system using anammox gel carrier can be applied to nitrogen removal from industrial effluent under low water temperature.
