【作者】 张博；

【导师】 季民；

【作者基本信息】 天津大学 ， 市政工程， 2017， 博士

【摘要】 利用预处理技术对污泥进行破解,是改善污泥厌氧消化性能的有效途径。本文采用超声和碱解的方法对高固污泥进行厌氧消化预处理,研究了单独超声、单独碱解和超声耦合碱解对污泥的破解及对厌氧消化的促进作用,采用超声碱解耦合工艺进行生产性试验,并分析高固污泥厌氧消化池中微生物群落结构特征,主要研究成果如下:开发出一种新型、高效、低能耗的密集多探头槽式超声波反应器,反应器体积为250 L,总功率为10 kW,污泥处理量可达5 m~3/h,能耗为2 kWh/m~3,相比国际上同类型的研究,处理量有2~5倍的提升,且能耗降低了50%。碱解高固污泥预处理试验发现,胞外聚合物可被先破解,微生物细胞壁在CaO投加量0.06 g/g-TS时才开始破解,CaO投加量0.08 g/g-TS时细胞膜开始破解。厌氧消化试验发现,胞外聚合物破解相比细胞结构破解对改善污泥甲烷产率贡献更多。超声耦合碱解高固污泥时存在协同作用,可以提高污泥中微生物胞外聚合物的破解程度,并在低碱量条件下,也可以破解细胞壁和细胞膜,溶出更多的有机物,使甲烷产率明显增加。进行了超声耦合碱解高固污泥的生产性试验,试验发现:超声耦合碱解预处理使高固污泥中化学需氧量(COD)溶出率达到19.5%~23.0%。能量平衡结果表明,超声耦合碱解预处理-厌氧消化系统在经济上是可行的。利用高通量测序分子生物学技术,对高固污泥厌氧消化系统中微生物的群落结构进行分析,研究发现:随固体浓度增加,氨氮和挥发性脂肪酸浓度逐渐升高,Firmicutes和Methanosaeta丰度逐渐降低,而Bacteroidete丰度逐渐升高。更多还原

【Abstract】 Disintegrating sludge with pretreatment technology is an effective way to enhance the anaerobic digestion performance.In this paper,ultrasonic and alkaline method were applied to pretreat the high-solid sludge.The disintegration effects and improvements of anaerobic digestion performance by individual ultrasonic pretreatment,individual alkaline pretreatment and coupled ultrasonic and alkaline pretreatment were studied.A full scale coupled ultrasonic and alkaline pretreatment test was carried out.The microbial community structure in the high-solid anaerobic digeste was studied.The main research results were as follows:A novel,efficient and energy saving multi-transducer ultrasonic path reactor was developed with a total volume of 250 L and a total power of 10 kW.The sludge could be pretreated with a capacity of 5 m~3/h and an energy consumption of 2 kWh/m~3.Compared with the full-scale ultrasonic reactors in the international studies,the capacity of this full-scale ultrasonic reactor was 2-5 times higher,and the energy consumption reduced by 50%.Test of high-solid sludge pretreated by alkaline pretreatment showed that the extracellular polymeric substances(EPS)was easy to be damaged and could be disintegrated firstly,the microbial cell wall began to be damaged when CaO dose was0.06 g/g-TS,and the disintegration of cell membrane was observed when CaO dose was higher than 0.08 g/g-TS.And it was found that EPS disintegration contributed more to biogas production than cell disintegration.There was a synergistic effect when coupled ultrasonic and alkaline pretreatment technology was used to disintegrate high-solid sludge.The pretreatment could improve the microbial EPS disintegration degree,and disintegrate the cell wall and cell membrane under low alkaline dose,thus more organic matters were released and methane yield was improved.A full-scale coupled ultrasonic and alkaline pretreatment test was established.It was found that the chemical oxygen demand(COD)solubilization of high-solid sludge reached 19.5%~23.0%.The energy balance results showed that the coupled ultrasonic and alkaline pretreatment-anaerobic digestion system is technically economically feasible.High-throughput sequencing molecular biology method was used to study the microbial community structure in anaerobic digester of high-solid sludge.The results illustrated that with the increase of solid concentration,the concentrations of volatile fatty acid(VFA)and ammonia nitrogen increased,and the abundances of Firmicutes and Methanosaeta decreased gradually,while the abundance of Bacteroidetes increased gradually.更多还原