污泥比表面积对蚯蚓堆肥系统中细菌群落组成及多样性的影响

Effect of specific surface area of sludge on community composition and diversity of bacterial community in vercomposting system

城镇污泥蚯蚓堆肥属于好氧堆肥范畴,污泥复氧能力是制约其堆肥效率的一个重要因素。污泥团粒尺寸不同,其比表面积不同,与氧接触的面积不同,降解效率也会有所差异。将城镇污泥制成5 mm和14.5 mm的粒状,比表面积分别为1.98×10^(-3) m^(2)/g、0.68×10^(-3) m^(2)/g,进行历时60 d的蚯蚓堆肥试验,探讨污泥与氧接触面积差异对细菌群落组成及多样性的影响。结果表明:在城镇污泥蚯蚓堆肥系统中,增大污泥比表面积能加速氨化和提前硝化进程,使污泥有机质降解程度更高,矿化速度更快;污泥比表面积大,微生物物种多样性低,优势度和均匀度高;拟杆菌门(Bacteroidetes)、变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、绿弯菌门(Chloroflexi)、绿菌门(Chlorobi)是受比表面积影响的主要细菌门类;污泥比表面积大,能分解纤维素的细菌菌门相对丰度占比高,与理化性质有显著相关性的细菌菌属种类多。

Vermicomposting of urban sludge belongs to aerobic composting,and the ability of sludge reoxygenation is an important factor restricting its composting efficiency.The specific surface area and the area in contact with the oxygen of sludge granule are different in size as well as degradation efficiency.In this study,the urban sludge was prepared into granules of 5 mm and 14.5 mm,and the specific surface area was 1.98×10^(-3) m^(2)/g,0.68×10^(-3) m^(2)/g.Vermicomposting experiments lasted for 60 days to explore the effect of the difference in the contact area between sludge and oxygen on the composition and diversity of bacterial communities.The physico-chemical properties of sludge were determined,and Biolog-ECO culture and high-throughput sequencing were carried out.The results show that in the urban sludge Vermicomposting system,the specific surface area of sludge particles has a significant effect on the physical and chemical indexes of sludge composting.The increase of the specific surface area of sludge can accelerate the ammonification and advance the nitrification process,and make the organic matter degradation degree of sludge higher and the mineralization speed faster.The species number and community diversity of large granular sludge are higher than those of the small granular sludge group,but the species dominance and evenness are lower than those of the small granular sludge group.Bacteroidetes,Proteobacteria,Actinobacteria,Chloroflexi and Chlorobi are the main bacteria affected by specific surface area.The proportion of anaerobe in the large-particle group is higher than that in the small-particle group.The proportion of 16 S rDNA in cellulose-decomposable 16 S rDNA in the small-particle group is higher than that in the large-particle group.The specific surface area of sludge is large,and the relative abundance of bacteria that can decomposition cellulose is high.Many bacteria genera are significantly related to physical and chemical properties.The change of the specific surface area of particles affects the functional bacteria genera related to sludge degradation.