Ciudad G, González R, Bornhardt C, Antileo C
Universidad de La Frontera, Cas. 54-D, Temuco-Chile.
Water Res. 2007 Dec;41(20):4621-9. doi: 10.1016/j.watres.2007.06.036. Epub 2007 Jun 21.
Sequencing batch (SBR) and continuous operation modes were applied using different pH control strategies to enhance partial nitrification in a biofilm rotating disk reactor. The pH control strategies were supervisory control in the range of 7.5-8.6 and fixed pH at 7.5 and 8.5, at dissolved oxygen (DO) concentrations in the range of 0.6-5.0 mg O(2)/L. Supervisory pH control enabled operation at a free ammonia concentration inhibitory to the nitrite-oxidizing bacteria (NOB) and an optimum for the ammonia-oxidizing bacteria (AOB). The results indicate that both operation modes were simultaneously controlled by oxygen transport and micro-kinetics (influenced by pH and NH(3)). The SBR mode with supervisory pH control presented more stable partial nitrification-nitrite accumulation >80% for 249 days than continuous operation. Molecular analyses showed that the SBR operation with supervisory pH control at low DO concentrations contributed to the enrichment of the AOB (>95%) over the NOB (<5%) populations. Therefore, it can be stated that a suitable pH control strategy can act as an enhancement factor of partial nitrification even under oxygen-transport-limiting conditions.
在生物膜转盘反应器中，采用序批式（SBR）和连续运行模式，并运用不同的pH控制策略来强化部分硝化作用。pH控制策略包括在溶解氧（DO）浓度为0.6 - 5.0 mg O₂/L的条件下，7.5 - 8.6范围内的监督控制以及固定pH值为7.5和8.5。监督pH控制能够在对亚硝酸盐氧化菌（NOB）具有抑制作用且对氨氧化菌（AOB）为最佳的游离氨浓度下运行。结果表明，两种运行模式均同时受氧传递和微观动力学（受pH和NH₃影响）的控制。采用监督pH控制的SBR模式在249天内呈现出比连续运行更稳定的部分硝化 - 亚硝酸盐积累，>80%。分子分析表明，在低溶解氧浓度下采用监督pH控制的SBR运行有助于氨氧化菌（>9５%）相对于亚硝酸盐氧化菌（<5%）种群的富集。因此，可以说即使在氧传递受限的条件下，合适的pH控制策略也可作为部分硝化作用的强化因素。
