IFAS工艺短程硝化过程中功能菌的动力学特性

实验采用生物膜-活性污泥复合工艺（IFAS），探究了不同进水NH₄⁺-N负荷以及游离氨（FA）浓度下的好氧氨氧化细菌（AOB）和亚硝酸盐氧化细菌（NOB）的动力学特性，考察了不同微生物聚集体（悬浮污泥和载体生物膜）对于NH₄⁺-N去除的贡献，同时对其中的生物吸附和生物降解进行定量分析.利用荧光原位杂交（FISH）技术观察了总菌、AOB和NOB的数量以及空间结构的变化.结果表明，随着进水NH₄⁺-N浓度逐渐升高，出水NO₃^--N浓度逐渐下降，NO₂^--N得到大量积累，当进水NH₄⁺-N浓度为480mg/L时，NH₄⁺-N去除率和亚硝酸盐氮积累率（NAR）分别稳定在95%和80%以上，而FA由（2.77±0.07）mg/L增加至（16.35±0.3）mg/L时，NAR由9.42%增加至83.31%，实现了对NOB的抑制.在NH₄⁺-N的去除过程中生物吸附和微生物降解分别占NH₄⁺-N去除量的3.4%和88.1%，悬浮污泥和生物膜中AOB占比分别由27.4%和10.3%增加至41.3%和18.1%，表明悬浮污泥比生物膜更有利实现对于AOB的富集.

Kinetic characteristics of functional bacteria in IFAS process for partial nitrification

The kinetic characteristics of aerobic ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) under different influent NH₄⁺-N loading and free ammonia (FA) concentration were studied by biofilm-activated sludge composite process (IFAS). The contributions of different microbial aggregates (suspended sludge and attached biofilm) to the removal of NH₄⁺-N were investigated, and the biological adsorption and biodegradation were analyzed quantitatively. The amount and spatial distribution of total bacteria, AOB, and NOB were observed by fluorescence in situ hybridization (FISH). The experimental results showed that with the increased of influent NH₄⁺-N concentration, the effluent NO₃^--N concentration decreased and the NO₂^--N accumulated a lot. When the influent NH₄⁺-N concentration was 480mg/L, the NH₄⁺-N removal rate and the nitrite accumulation rate (NAR) were stable above 95% and 80%, respectively, while the FA increased from (2.77±0.07) mg/L to (16.35±0.3) mg/L, and the NAR increased from 9.42% to 83.31%, which achieved the inhibition of NOB. In the process of NH₄⁺-N removal, biossorption and microbial degradation accounted for 3.4% and 88.1% of NH₄⁺-N removal, respectively. The ratio of AOB in suspended sludge and biofilm increased from 27.4% and 10.3% to 41.3% and 18.1%, respectively, indicating that suspended sludge was more beneficial to enrichment of AOB than biofilm.