填料类型和曝气条件对生物栅微生物群落的影响

以水生植物和填料为要素构建生物栅装置,用以强化处理富营养化水体.实验采用6m3.d-1的中试规模,7个廊道并联运行,连续进出水.研究不同的填料类型和不同曝气条件下的污染去除效果以及填料生物膜微生物群落结构的变化.结果表明,填料在污染去除中起重要作用,投加填料的反应池CODCr、总氮和氨氮的去除率较无填料对照池分别提高了42.1%~52.2%,24.4%~47.8%和58.7%~71.4%.悬浮填料生物膜微生物相对处于好氧生境,有利于COD和NH4+的好氧氧化去除,而组合填料和新型填料存在兼性厌氧的生境,有利于总氮的去除.采用间歇曝气的方式可以一定程度地提高系统污染去除效率.ERIC-PCR指纹图谱分析表明,填料挂膜阶段,3种填料生物膜带型相似,随着系统挂膜成熟及稳定运行,填料生物膜带型分化成两大类型.悬浮填料为一大类型,组合填料和新型填料为另一类型.3种填料生物膜微生物种群丰富度明显提高.间歇曝气的3号和5号条带微生物的种群丰富度高于未曝气的2号和4号,有利于污染物的去除.总之,随着系统的稳定运行,填料生物膜微生物多样性指数显示出逐渐增大的趋势,表明系统中微生物种群趋于多样化,系统处于良好的稳定状态.

Influences of aeration and packing types on the biofilm microbial community of biological grid device

A biological grid device, consisting of hydrophytes and packings, was constructed to reinforce treatment of eutrophic river water. A pilot scale experiment was performed to study the influences of aeration and packing types on pollutant removal and characteristics of microbial community on biomembrane. Seven reaction tanks were parallelly connected and the process was continuously influent and effluent, with water inflow designed to be 6 m3· d-1. The results show that packings, working as microbial carriers, have important roles on pollutant removal. Reaction tanks with packings have higher removal efficiencies of COD，Cr，total N and NH+4，N, with 42.1%～52.2%, 24.4%～47.8% and 58.7%～71.4% higher than those with none packing tanks, respectively. Compared with suspended packings, combined packings and the new type packings have complicated microsetting, thus have higher removal efficiencies of total N. At the same time, intermittent aeration have higher pollutant removal efficiency for all three packings than none aeration ones. ERIC-PCR fingerprinting analysis shows that similar band patterns have been found from biofilm samples of the three kinds of packings before the maturity of biofilms. Along with the maturity of biofilms and system stabilization, biofilm band patterns are divided into two types，suspended carriers have one kind and the combined packings as well as the new type packings have the other. At the same time, microbial population diversity increases and pollutant removal efficiency goes up for all the three packings types. Intermittent aeration tanks （No. 3 and No. 5） have more microbial population diversity than none aeration ones (No. 2 and No. 4), which are in favor of pollutant removal. Therefore，along with stable operation，microbial population diversity index increases and system is in good condition.