污泥投配率对污泥中温厌氧消化效果影响的试验研究

Effect of sludge dosage rate on mesophilic anaerobic digestion of excess activated sludge

试验装置采用半连续流污泥中温厌氧消化反应器，污泥培养接近成熟后开始每天按不同污泥投配率加泥和排泥。结果表明：污泥投配率在3％～10％时，有机物分解率先增大后减小，去除率均在30％以上；污泥投配率在15％和20％时，污泥的有机物去除率非常小；污泥投配率在5％时，有机物分解率最大为41．2％；单位VSS产气量随污泥投配率的增大而呈先急剧上升后逐渐下降的趋势，当污泥投配率为5％时，单位VSS产气量为0．60L／g，符合美国污水处理厂设计手册标准，其他污泥投配率下该指标均小于0．4L／g。因此，认为实验用污泥中温消化的最佳污泥投配率为5％，这时污泥的可消化性较好。

Semi-continuous sludge anaerobic digestion reactor with temperature automatically controlled （35± 1 ） ℃ under mesophilic condition was employed in this sludge dosage rate experimentation. After sludge being adaptable to mature, the fresh sludge was added into the reactor and digested sludge exited at different dosage rate. The results showed that when dosage rate was between 3% and 10%, decomposition rate of organic materials initially increased, then decreased later, and the value of decomposition rate was over 30%. Decomposition rate of organic materials approached maximum of 41.2 % at the dosage rate of 5 %. In contrast, the removal of organic materials was significantly lower at the sludge dosage rate in the range of 15%-20%. On the other hand, with the increasing of dosage rate, specific VSS gas production slowly descended with the maximum of 0. 60 L/g at 5% dosage rate and this data was below 0.4 L/g under other dosage rate conditions, which coincide well with the design handbook of sewage treatment plant of U. S. A.. Therefore, it is concluded that the optimu best condition for sludge digestion was at the dosage rate of 5 %.