Effect of Temperature on Nitrogen Removal Performance of Marine Anaerobic Ammonium Oxidizing Bacteria

Abstract

The effect of temperature on the nitrogen removal performance of marine anaerobic ammonium oxidizing bacteria processing sewage seawater was studied by employing an ASBR reactor, and the dynamic characteristics of the marine anaerobic ammonium oxidizing bacteria at different temperatures were simulated by modified Logistic model. The experimental results indicated that the nitrogen removal performance was affected little at 25-35℃. The total nitrogen removal efficiency (TNRE) remained at (82±2)% and the total nitrogen removal rate (TNRR) was stabilized at (0.62±0.01) kg·(m3·d)-1. When the temperature was 20℃, TNRE increased from 59% at the beginning to 79% after 13 days. This indicated that the marine anammox bacteria still had strong ability of nitrogen removal, and the reactor in the low temperature treatment of sewage containing seawater had a good potential. However, when the temperature dropped to 10-15℃, the nitrogen removal performance of the reactor was inhibited. TNRE decreased to (40±8)% and (11±4)%, respectively. Besides, TNRR also decreased to (0.30±0.04) kg·(m3·d)-1 and (0.08±0.03) kg·(m3·d)-1, respectively. According to the Arrhenius equation, the activation energy for marine anaerobic ammonium oxidation reaction was 26 kJ·mol-1 at 25-35℃, and the activation energy of marine anaerobic ammonium oxidation reaction was 76 kJ·mol-1 at 10-25℃. In addition, dynamic analysis was performed by Logistic model and the NRE and effluent total nitrogen concentration (ceff) at different temperatures were forecasted. The correlation coefficient R2 was between 0.9668 and 0.9957.