温度和储存基质对储存后厌氧颗粒污泥特性的影响

Effect of temperature and substrate on anaerobic granular sludge characteristics after preservation

温度和储存基质是颗粒污泥储存过程中的重要控制因子.本文选取某IC反应器内典型厌氧颗粒污泥(AGS)为对象,研究了温度和储存基质对储存后AGS理化性质、结构特征和菌群结构的影响.结果显示,常温(20℃)和添加基质可减缓储存过程中AGS粒径下降,维持形状稳定.中温(35℃)利于削减储存液中积累的酪氨酸、色氨酸等芳香性氨基酸,但会增加难降解腐殖酸类物质积累.中温条件适于短期储存(1.5个月)过程中维持颗粒污泥结构稳定,而常温适于长期储存(3个月).不同条件储存后,污泥中的优势菌群在门水平和属水平相似,分别为Chloroflexi、Bacteriodetes、Euryarchaeota、Hyd24-12和Anaerolinea、Bacteroidales、T78、Methanobacterium、Methanosaeta.但功能菌群受温度影响变化显著,常温条件下产甲烷菌群相对丰度下降至2.70%~3.00%,而发酵菌群丰度提高至65.90%~67.40%.中温和基质对污泥菌群结构影响较小.综合而言,常温利于维持AGS理化性能和结构稳定,中温利于维持菌群活性和结构稳定,基质添加利于增强AGS的综合性能,但效果不显著.

Temperature and stored substrate are key factors affecting the preservation of anaerobic granular sludge（ AGS）. In the present work,the typical AGS in an internal cycling reactor was taken to investigate the effects of temperature and substrate on the physiochemical profiles,morphology and structure and microbial community of the sludge after preservation. The results showed that,ambient temperature（ 20 ℃） and additional substrate could slow down the decline of the particle size and benefit the stability of the sludge shape. After 3 months storage,tyrosine,tryptophan and other aromatic amino matters would be present in the storage liquid. However,their amounts at the mesophilic temperature（ 35 ℃） test were less than those at the ambient temperature test. It was noted that,the refractory humic matters were easier to be accumulated at mesophilic temperature. To maintain good granular morphology and structure profiles,mesophilic and ambient temperatures were preferred for short-term preservation（ 1.5 months） and long-term preservation（ 3. 0 months）, respectively. The dominant microbes at the phylum and genus levels were similar as Chloroflexi, Bacteriodetes,Euryarchaeota,Hyd24-12 and Anaerolinea,Bacteroidales,T78,Methanobacterium,Methanosaeta. However,the functional microbes were remarkably affected by the ambient temperature. The relative abundance of methanogenic microbe（ archaea） decreased to 2.70% ~ 3.00%,and the relative abundance of fermentative microbe（ bacteria） increased to 65.90% ~ 67.40% after storage at ambient temperature. Mesophilic temperature and stored substrate had little effects on the microflora of the sludge. In general,ambient temperature would be beneficial for the stability of physiochemical profile,morphology and structure of sludge,and mesophilic temperature would be helpful in maintaining the methanogenic activity and microbial community.