高钙废水颗粒污泥中古菌菌群结构变化的分析

为了解高浓度Ca~(2+)与颗粒污泥中古菌菌群结构的关系,利用高通量测序分析IC(Internal Circulation)反应器(以废纸造纸废水为处理对象)内不同高度处颗粒污泥中古菌菌群组成,并利用SEM(Scanning Electron Microscope)和EDS(Energy Dispersive X-ray Spectroscopy)分析颗粒污泥的形态结构和元素组成,同时借助红外光谱和XRD(X-ray diffraction)分析不同高度处颗粒污泥化学结构中各官能团的分布情况和无机成分.结果表明,随着反应器高度的增加,颗粒污泥中的无机成分CaCO_3也随着增加,而种泥中钙含量只有1.81%.种泥和ICR反应器内的颗粒污泥中古菌在门分类水平上主要包括Euryarchaeota和Bathyarchaeota,两者之和占90%以上.在属分类水平上,主要包括Methanosaeta、Methanoregula、Methanobacterium、Methanosarcina、Methanolinea、Methanospirillum等.种泥中古菌的物种多样性要明显高于IC反应器中,在IC反应器中不同高度处古菌生物多样性由高到低的顺序是5 m2 m7 m,5 m处的古菌物种更加丰富.随着反应器高度的增加,乙酸营养型甲烷菌的相对丰度呈现递增趋势,氢营养型甲烷菌则呈现递减趋势,而种泥中氢营养型甲烷菌相对丰度较大.这表明颗粒污泥在高钙废水的长期作用下,氢营养型甲烷菌的相对丰度减少,乙酸营养型甲烷菌的相对丰度增多,系统中古菌物种的相对丰度和多样性有所下降.CaCO_3沉淀使颗粒污泥的产甲烷活性降低,主要表现为其对氢营养型甲烷菌具有较大的抑制作用.

Analysis of the shift of archaea community structure in granular sludge of high calcium wastewater

In order to understand the relationship between high concentration of Ca²⁺ and the archaea community structure in granular sludge, the archaea community compositions was analyzed at different heights in IC (Internal circulation) reactor by high-throughput sequencing. The morphological structure and elemental composition of granular sludge were also analyzed by SEM (Scanning Electron Microscope) and EDS (Energy Dispersive X-ray Spectroscopy) respectively, and the distribution of functional groups and inorganic components in the chemical structure of granular sludge were analyzed by infrared spectroscopy and XRD (X-ray Diffraction) respectively. The results show that the inorganic component CaCO₃ in granular sludge increased with the increase of reactor height, while the calcium content in seed sludge was only 1.81%. The archaea in both seed sludge and the granular sludge in IC mainly included Euryarchaeota and Bathyarchaeota at the phylum taxonomic level, and the sum of the two accounted for more than 90%. At the genus level, the compositions included Methanosaeta, Methanoregula, Methanobacterium, Methanosarcina, Methanolinea, Methanospirillum, etc. The species diversity of archaea in seed sludge is higher than that in IC. The relative abundance of acetotrophic methanogens also increased with the increase of reactor height, while hydrogenotrophic methanogens decreased. The results show that the relative abundance and diversity of archaeal species in the system decreased under the long-term action of high calcium wastewater. The precipitation of CaCO₃ reduced the methanogenic activity of granular sludge, which is mainly manifested by its greater inhibition of hydrogenotrophic methanogens.