Process performance and change in sludge characteristics during anaerobic digestion of sewage sludge with ozonation.
Process performance and change in sludge characteristics during anaerobic digestion of sewage sludge with ozonation.
复制标题
污水污泥臭氧化厌氧消化过程中的工艺性能和污泥特性变化。
DOI：
10.2166/wst.2004.0620
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
H. Harada
中科院分区：
文献类型：
--
作者：
R Goel;K. Komatsu;H. Yasui;H. Harada
研究了一种将厌氧消化与臭氧化相结合并在长 SRT 下运行的新工艺配置，其目的是减少现场污泥量并提高沼气回收率。根据使用初级和二级城市污水污泥混合物进行的长期中试规模连续实验的数据，评估了固体还原效率和其他重要工艺参数（例如无机固体积累、污泥粘度变化和脱水特性）的工艺性能。由于污泥臭氧化和长SRT，在反应器固体浓度为6.5%时，VSS降解效率达到约80%。发现反应器中积聚了大量的无机固体（>50%），主要由酸不溶物和铁化合物组成。然而，消化污泥中积累的高无机含量并没有导致在高固体浓度下观察到的污泥粘度增加。发现污泥粘度很大程度上取决于有机固体浓度而不是总固体含量。此外，消化污泥中无机物含量越高，污泥脱水性越好。为了快速评估新工艺的经济可行性，提出了基于消化污泥处置单位成本除以单位电力成本的经济指标。
A new process configuration combining anaerobic digestion with ozonation, and operated at long SRT, was studied with the objective of on-site reduction in sludge quantity and improving biogas recovery. The process performance with respect to solid reduction efficiency and other important process parameters like accumulation of inorganic solids, changes in sludge viscosity and dewatering characteristics were evaluated from the data of long term pilot scale continuous experiments conducted using a mixture of primary and secondary municipal sewage sludge. Due to sludge ozonation and long SRT, high VSS degradation efficiency of approximately 80% was achieved at a reactor solid concentration of 6.5%. A high fraction of inorganic solid (>50%) consisting mainly of acid insoluble and iron compounds was found to accumulate in the reactor. The high inorganic content accumulated in the digested sludge did not, however, contribute to the observed increase in sludge viscosity at high solid concentration. The sludge viscosity was largely found to depend on the organic solid concentration rather than the total solid content. Moreover, higher inorganic content in the digested sludge resulted in better sludge dewaterability. For a quick assessment of the economic feasibility of the new process, an economic index based on the unit cost of digested sludge disposal to unit electric cost is proposed.