连续流气提式反应器中有机物去除和氮转化的行为

以城市污水为处理对象,以絮状污泥为接种污泥,在连续流气提式好氧颗粒污泥流化床(CAFB)反应器中成功培养得到好氧颗粒污泥.探讨了CAFB中颗粒污泥的形成过程、生物多样性、有机物的去除行为及氮转化特性.研究结果表明,CAFB运行第7天颗粒污泥占主要优势,系统中依次出现原、后生动物,表明颗粒污泥趋于成熟.CAFB反应器中培养的好氧颗粒污泥具有良好的COD及NH4+-N去除能力.稳定运行阶段,当进水的COD容积负荷在1.5 ～3.5 kg COD/(m3·d)的范围时,COD的去除负荷稳定在1.0～2.0 kg COD/(m3·d).控制水力停留时间为(4 ±0.25)h、溶解氧质量浓度为(5 ±0.5) mg/L,可达到最高的硝化效率,但此控制条件下反硝化作用不明显.分析认为,作为完全混合式反应器的CAFB,需要较严格的控制溶解氧才能实现同步硝化反硝化作用.

Performances of organic removal and nitrogen transformation in a continuous airlift reactor

Aerobic granules were formed successfully in a continuous-flow airlift fluidized bed (CAFB), which with municipal wastewater as the treating object and flocculent sludge as the seeding. The granulation course, biological diversity, organic matters removal and nitrogen transformation performances in the CAFB were especially discussed. It was found that aerobic granules were dominant in the CAFB after 7 days running. Protozoa and metazoans were observed successively during the running period, which indicated that the biomass was matured gradually. The CAFB reactor presented great COD and NH₄⁺-N removal ability. In the stability running stage, the COD removal loading rates maintained at 1.0~2.0 kg COD/(m³·d) even though the organic loading rate increased in a wide range of 1.5~3.5 kg COD/(m³·d). The nitrification efficiency was best if the hydraulic retention time and the dissolved oxygen concentration could be controlled at (4±0.25)h and (5±0.5)mg/L, respectively. However, the denitrification function was not obviously under these conditions. As a complete mixing bioreactor, a more strictly control on dissolve oxygen concentration was necessary to realize simultaneous nitrification and denitrification.