连续/间歇曝气下MBBR-亚硝化生物膜特性

本文分别以连续曝气和间歇曝气方式长期运行两套亚硝化移动床生物膜反应器，对比分析两种曝气方式下亚硝化生物膜特性差异和变化.研究表明，连续曝气和间歇曝气均可实现亚硝化生物膜生长（K_d> 0），但间歇曝气下生物膜连续脱落对生物总量基本无影响，生物膜生长过程更加稳定，且当亚硝化运行稳定后，间歇曝气可获得更高的生物总量（1.42g/m²）.而连续曝气下生物膜可获得更高的蛋白质/多糖（PN/PS=1.8~2.0）和蛋白质/挥发性固体（PN/VS=0.145）以及更低的腐殖质/挥发性固体（HS/VS=0.05）和死细胞占比（13.66%）.这说明连续曝气下生物膜中活性生物量占比更高，惰性生物量占比更低，活细胞占比更高，因而生物膜活性更高，微生物代谢更活跃.荧光实时定量PCR结果显示，以连续曝气运行的MBBR生物膜中亚硝化菌总量远高于间歇曝气，连续曝气更利于亚硝化菌的生长富集（2.36copies×10⁸/g > 0.25copies×10⁸/g）.

Characteristics of MBBR-nitrite biofilm under continuous/intermittent aeration

The changes in the characteristics of nitrosation biofilm were compared in two long-running moving-bed biofilm reactors (MBBR) with two different aeration modes, i.e. continuous aeration and intermittent aeration regimes. The results showed that both continuous aeration and intermittent aeration could achieve the stable growth of the nitrosation biofilm(K_d>0). When with the intermittent aeration regime, continuous biofilm detachment had no effects on the total biomass, and the biofilm growth was more stable. The biofilm under intermittent aeration could obtain a higher total biomass (1.42g/m²) when the MBBR reactor operation was stable. While with the continuous aeration regime, the biofilm could obtain higher PN/PS (1.8~2.0) and PN/VS (0.145), and lower HS/VS (0.05) and the percentage of dead cell (13.66%). This indicated that the biofilm under continuous aeration had a higher proportion of active biomass and living cells, a lower inert biomass, so the biofilm activity was higher and microbial metabolism was more active. The q-PCR results further confirmed that the amount of ammonia-oxidizing bacteria (AOB) was much higher in the biofilm with the intermittent aeration regime than that with the continuous aeration regime. It seemed that the continuous aeration was more beneficial to the AOB growth than that of the intermittent aeration regime in the MBBR (2.36copies×10⁸/g > 0.25copies×10⁸/g).