Effect of carbon source on nitrogen removal in anaerobic ammonium oxidation (anammox) process

Anaerobic ammonium oxidation (anammox) has been regarded as an efficient process to treat high-strength wastewater without organic carbon source. To investigate nitrogen removal performance of anammox in presence of organic carbon source can broaden its application on organic wastewater treatment. In this work, effect of carbon source on anammox process was explored. Operating temperature was set at 35 ± 1°C. Influent pH and hydraulic retention time were 7.5 and 6 h, respectively. Effluent NH4+−N was affected little with COD no more than 480 mg/L. Independent of carbon source content, nitrite removal rate was around 99%. The variation of ΔNO2−−N/ΔNH4+−N lagged behind ΔNO3−−N/ΔNH4+−N at high COD content, and pH could be used as an indicator for NH4+−N removal. Specific anammox activity dropped from 0.39 to 0.19 kgNH4+−N/(kgVSS·d) at COD = 720 mg/L. The remodified logistic model was quite appropriate for describing the nitrogen removal kinetics and predicting the performance of anammox process in presence of carbon source.