Mahmoud Nidal, Zeeman Grietje, Gijzen Huub, Lettinga Gatze
Department of Agricultural, Environmental and Systems Technology, Sub-Department of Environmental Technology, Wageningen University, PO Box 8129, Wageningen 6700 EV, The Netherlands.
Water Res. 2004 Feb;38(4):983-91. doi: 10.1016/j.watres.2003.10.016.
The effect of sludge retention time (SRT) and process temperature on the hydrolysis, acidification and methanogenesis of primary sludge was investigated in completely stirred tank reactors (CSTRs). The CSTRs were operated to maintain SRTs of 10, 15, 20 and 30 days at process temperatures of 25 degrees C and 35 degrees C. The rates of hydrolysis and the biodegradability of primary sludge were assessed in batch reactors incubated at 15 degrees C, 25 degrees C and 35 degrees C. The results revealed that the major amount of sludge stabilisation occurred between 0 and 10 days at 35 degrees C and 10 and 15 days at 25 degrees C. Hydrolysis was found to be the rate limiting-step of the overall digestion process, for the reactors operated at 35 degrees C and 25 degrees C, except for the reactor operated at 10 days and 25 degrees C. At the latter conditions, methanogenesis was the rate-limiting step of the overall digestion process. Proteins hydrolysis was limited to a maximum value of 39% at 30 days and 35 degrees C due to proteins availability in the form of biomass. The biodegradability of primary sludge was around 60%, and showed no temperature dependency. The hydrolysis of the main biopolymers and overall particulate COD of the primary sludge digested in CSTRs were well described by first-order kinetics, in case hydrolysis was the rate-limiting step. Similarly, the hydrolysis of the overall particulate COD of the primary sludge digested in batch reactors were described by first-order kinetics and revealed strong temperature dependency, which follows Arrhenius equation.
在完全搅拌釜式反应器（CSTR）中研究了污泥停留时间（SRT）和工艺温度对初沉污泥水解、酸化和甲烷化的影响。CSTR在25℃和35℃的工艺温度下运行，以维持10、15、20和30天的SRT。在15℃、25℃和35℃下孵育的间歇反应器中评估了初沉污泥的水解速率和生物降解性。结果表明，在35℃时，大部分污泥稳定化发生在0至10天之间；在25℃时，发生在10至15天之间。对于在35℃和25℃下运行的反应器，除了在10天和25℃下运行的反应器外，水解被发现是整个消化过程的限速步骤。在后者条件下，甲烷化是整个消化过程的限速步骤。由于生物质形式的蛋白质可用性，在30天和35℃时蛋白质水解限制在最大值39%。初沉污泥的生物降解性约为60%，且不显示温度依赖性。在水解是限速步骤的情况下，CSTR中消化的初沉污泥的主要生物聚合物水解和总颗粒化学需氧量（COD）可用一级动力学很好地描述。同样，间歇反应器中消化的初沉污泥的总颗粒COD水解可用一级动力学描述，并显示出强烈的温度依赖性，符合阿伦尼乌斯方程。
