保藏温度对厌氧氨氧化颗粒污泥特性的影响

为考察保藏温度对厌氧氨氧化污泥颗粒特性的影响,同时优化保藏厌氧氨氧化颗粒污泥温度参数,本试验首先通过HRT调控进水基质负荷培养厌氧氨氧化颗粒污泥,并采用KHCO3和Na HCO3交替提供无机碳源。然后分别在–40℃、4℃、(27±4)℃室温和35℃条件下避光保藏。结果表明,Na HCO3可代替KHCO3作为厌氧氨氧化菌生长的无机碳源。相比于其他保藏温度,4℃保藏能够较好地维持生物量和生物活性,同时能较好地维持颗粒污泥的沉降性能、颗粒污泥和细胞结构完整性。在保藏过程中,一阶衰减指数模型可拟合厌氧氨氧化颗粒污泥生物量及活性的衰减过程,衰减指数与胞溶程度正相关,而且生物量的衰减比活性的衰减更快。同时,颗粒污泥胞外聚合物中蛋白质与多糖的比值(PN/PS)和血红素不能有效指示保藏过程中颗粒污泥沉降性能和活性的变化,而生物活性与胞溶程度呈负相关。

Influence of preservation temperature on the characteristics of anammox granular sludge

To study the effect of preservation temperature on the characteristics of anaerobic ammonium oxidation (Anammox) granules and optimize the preservation temperature of anammox granules, the anammox granules were cultivated in an upflow anaerobic sludge bed reactor through adjusting the hydraulic retention times, and the inorganic carbon with KHCO3/NaHCO3 was alternately supplied. Subsequently, the enriched anammox granules were preserved at -40, 4 and 35 °C, and ambient temperature of (27±4) °C. NaHCO3 can be used as the inorganic carbon for the growth of anaerobic ammonium oxidizing bacterium (AnAOB). The best preservation temperature was 4 °C for maintaining anammox biomass, anammox activity, settleability, and the integrity of the anammox granule and AnAOB cell structure. During the preservation period, the first-order exponential decay model can simulate the decay of anammox biomass and activity, and the decay coefficients (bAN) of anammox biomass and activity had positive correlation with the degree of AnAOB cell lysis. Meanwhile, the rate of anammox biomass decay was larger than that of anammox activity. The ratio of protein to polysaccharide in extracellular polymeric substances and heme c cannot effectively indicate the changes of anammox granules settleability and activity, respectively, and the bioactivity has a negative association with the degree of AnAOB cell lysis.