pH冲击对海洋厌氧氨氧化菌处理含海水污水脱氮效能的影响

采用ASBR反应器,研究了pH冲击对海洋厌氧氨氧化菌处理含海水污水脱氮效能的影响,并利用Andrew模型和Ratkowsky模型模拟pH冲击下海洋厌氧氨氧化菌的脱氮过程.结果表明,当pH在7~8时,反应器的脱氮效果最佳,氨氮去除负荷(NRR)稳定在(0.30±0.04)kg·(m~3·d)~(-1),总氮去除率(TNRE)在(76.73±5.74)%;当pH为8.5时,游离氨(FA)的平均浓度为14.22 mg·L~(-1),该FA浓度对NRR的影响较小,NRR仍维持在(0.30±0.02)kg·(m~3·d)~(-1)左右,但是NO_2~--N在pH的直接影响下出现了积累,不能够完全去除,此条件不利于反应器的稳定运行;当pH为6.5和9时,FA浓度分别为0.22mg·L~(-1)和37.84 mg·L~(-1),NRR分别低至(0.10±0.02)kg·(m~3·d)~(-1)和(0.15±0.02)kg·(m~3·d)~(-1),且TNRE仅为(23.04±9.88)%和(42.12±5.52)%.海洋厌氧氨氧化菌在碱性条件下的耐受性强于酸性条件.采用修正的Andrew模型进行拟合,得到了NRR与FA之间的相互关系,同时还可以得到NRR_(max)、k_S和k_I等参数,对于表征海洋厌氧氨氧化菌的脱氮过程具有实际意义.

Effect of pH Shock on Nitrogen Removal Performance of Marine Anaerobic Ammonium-Oxidizing Bacteria Treating Saline Wastewater

The effect of pH shock on nitrogen removal performance of marine anaerobic ammonium-oxidizing bacteria (MAAOB) treating saline wastewater was studied by employing an ASBR reactor. Dynamic characteristics of the MAAOB were simulated by the Andrew model and Ratkowsky model. The results indicated that the reactor had the best nitrogen removal efficiency when the pH value was 7-8. The nitrogen removal rate (NRR) was (0.30±0.04) kg·(m³·d)^-1, and the total nitrogen removal efficiency (TNRE) was (76.73±5.74)%. When the pH value was 8.5, FA had a mean concentration of 14.22 mg·L^-1 and little effect on nitrogen removal. The NRR was (0.30±0.02) kg·(m³·d)^-1. However, NO₂^--N accumulated and it was not completely removed. When the pH values were 6.5 and 9, the concentrations of FA were 0.22 mg·L^-1 and 37.84 mg·L^-1, respectively, the NRRs were (0.10±0.02) and (0.15±0.02) kg·(m³·d)^-1, and the TNREs were (23.04±9.88)% and (42.12±5.52)%. The tolerance of the MAAOB in alkaline condition was stronger than that in acidic condition. The Andrew model was modified to determine the relationship between NRR and FA. Other parameters such as NRR_max, k_S, and k_I were also achieved simultaneously. These are key to describing the nitrogen removal process of MAAOB.