污泥性质对微波预处理-厌氧消化的影响及古菌群落结构分析

Impacts of Sludge Characteristics on Anaerobic Digestion with Microwave Pretreatment and Archaeal Community Structure Analysis

污泥性质对预处理强化厌氧消化工艺的效果有较大影响.本研究对比了某实际污水厂A^2O工艺和A^2O-MBR工艺产生的剩余污泥在微波预处理-厌氧消化过程中污泥性质的变化与产气效果,并考察了在预处理和厌氧消化过程中污泥的古菌群落结构变化.结果表明,A^2O工艺剩余污泥有机质含量比A^2O-MBR污泥高出16. 4%(分别为66. 4%和50. 0%),SCOD、溶解性蛋白质和多糖分别为后者1. 24、2. 02和4. 84倍,具有更好的可生物降解性.虽然预处理对生物降解性差的A^2O-MBR污泥有机物释放效果更好,但A^2O污泥在微波预处理-厌氧消化后产甲烷量比相应处理后的A^2O-MBR污泥多26. 1%.两种剩余污泥的古菌群落结构差异较大,A^2O-MBR污泥中甲烷丝菌属和甲烷八叠球菌属丰度分别比A^2O污泥多3. 68%和19. 73%.预处理对古菌群落的丰富度和均匀度影响相对较小,但厌氧消化后波动较大.污泥中有机组分不同是引起古菌群落结构变化的重要影响因素.

Sludge characteristics is an important factor in sludge pretreatment and anaerobic digestion（ AD） efficiency. Therefore,waste sludge of anaerobic-anoxic-aerobic（ A^2 O） and A^2 O-membrane bioreactor（ MBR） wastewater treatment processes from a fullscale wastewater treatment plant were taken,and the variations of sludge characteristics and performance during microwave pretreatment and AD were compared. The succession of archaeal community structure during the sludge treatment was also investigated. A^2 O waste sludge showed better biodegradability than A^2 O-MBR waste sludge did,with 16. 4% higher organic matter content（ 66. 4% vs.50. 0%）,soluble chemical oxygen demand（ COD）（ 1. 24 fold）,soluble protein（ 2. 02 fold）,and polysaccharides（ 4. 84 fold）.Although the efficiency of microwave pretreatment for A^2 O-MBR waste sludge was better than that for A^2 O waste sludge,the latter sludge produced 26. 1% more methane than the former did. The two types of waste sludge showed different archaeal community structures. The abundances of Methanothrix and Methanosarcina in A^2 O-MBR waste sludge were 3. 68% and 19. 73% higher than that in A^2 O waste sludge. The richness and evenness of archaeal communities slightly changed after pretreatment,but significantly changed after AD. The Chao1 index increased by 54. 0%-68. 8% after AD,whereas the Pielou index decreased by 16. 2%-34. 6%.Redundancy analysis showed that the organic components of waste sludge contributed to the succession of archaeal community structure.