低基质浓度下生物膜亚硝化工艺的快速启动及其运行效能

采用多孔凝胶填料,在低氨氮浓度下接种亚硝化絮体污泥进行填料挂膜,研究了反应器中填料的挂膜过程和不同DO/${{rm{NH}}_{rm{4}}^{rm{ + }}}$下亚硝化效果,采用MiSeq高通量测序技术分析了反应器中微生物种群结构。结果表明：在初始的1~3 d,有大量悬浮絮体污泥进入填料内部,反应器中基本无絮体污泥;随后填料内部的微生物不断由内向外生长,填料表观颜色不断加深,30 d时填料挂膜成功;DO/$ {{rm{NH}}_{rm{4}}^{rm{ + }}}$比值为0.09~0.2,氨氮容积负荷为1 kg·(m³·d)⁻¹时,亚硝化效果最好,亚硝积累率最高达86.13%。随着DO/$ {{rm{NH}}_{rm{4}}^{rm{ + }}}$的比值增加,亚硝积累率有所下降。批次实验结果表明,通过控制DO/$ {{rm{NH}}_{rm{4}}^{rm{ + }}}$的值,能够使生物膜表面形成一层耗氧屏障,则生物膜内部所能利用的氧有限,以此达到抑制NOB的目的。微生物分析结果表明：生物膜中AOB/NOB值为3,AOB在硝化细菌中占主导地位,生物膜中厌氧氨氧化菌得到富集,在34 d时丰度增加至25.13%,符合反应器总氮去除率上升的特征。

Fast start-up of nitrosation biofilm process and its performance with low strength sewage

The growth of biofilm on carriers and the stability of nitrification in the reactor were studied by inoculation of nitrifying floc sludge at low ammonia concentration with porous gel carriers, and the microbial population structure in the reactor was analyzed with high throughput sequencing technology. The results showed that large amounts of suspended flocs entered the carriers during the initial 1~3 days, and almost no flocs appeared in the reactor. Then the microorganisms inside the carriers grew continuously from the inside to the outside, and the apparent color of the carriers deepened continuously. On the 30th day, the mature biofilm was successfully formed, and its surface was brick red. When the ratio of DO to $ {rm{NH}}_{rm{4}}^{rm{ + }}$ ranged from 0.09~0.2 and the volume load of ammonia nitrogen was 1 kg·(m3·d)−1, nitrite accumulation rate reached to 86%. With the increase of the ratio of DO to $ {rm{NH}}_{rm{4}}^{rm{ + }}$, a slight decrease of nitrite accumulation rate occurred. The batch tests showed that AOB could use dissolved oxygen to form a barrier to consume oxygen on the surface of the biofilm by controlling the value of DO/$ {rm{NH}}_{rm{4}}^{rm{ + }}$, and the dissolved oxygen in the internal biofilm was limited, and the purpose of inhibiting NOB was achieved. The results of microbial analysis showed that the ratio of AOB to NOB in the biofilm was 3, and AOB played a dominant role in Nitrifying bacteria. In addition, the ANAMMOX bacteria were enriched in the biofilm, and the abundance increased to 25.13% after 34 d, which was consistent with the increase of total nitrogen removal rate in the reactor.