CAST+A工艺的污泥减量及除污效能研究

Sludge Reduction and Pollutant Removal Performance in CAST/Anaerobic Tank Process

在CAST工艺的污泥回流段加入一个厌氧反应罐而构成CAST+A工艺,并通过调节厌氧反应罐的停留时间分别为6、9和12 h,考察其污泥减量效果。两个月的监测表明,该工艺在不同停留时间下的污泥产率系数分别稳定在0.33、0.17和0.20 gMLSS/gCOD,相对于CAST工艺其减量率分别为21.42%、59.52%和52.38%。经分析,污泥衰减是实现污泥减量的主要原因。加入厌氧反应罐后,对去除COD和氨氮的影响较小,对总氮的去除效果有所改善,除磷效果则随停留时间的延长而逐渐降低。

An anaerobic tank was added in the sludge return section of a CAST process to create a CAST/A process. The sludge reduction in the CAST/A process was investigated by regulating the residence time of the anaerobic tank to 6 h, 9 h and 12 h. The results from two months of monitoring showed that the sludge yield coefficients were stabilized at 0.33,0.17 and 0.20 gMLSS/gCOD for the three resi- dence times. The corresponding sludge reduction rates were 21.42% , 59.52% and 52.38%. By analy- sis, sludge decay was the main cause of achieving sludge reduction. After adding the anaerobic tank, the removal of COD and ammonia nitrogen was little affected, while the removal efficiency of TN was im- proved. However, the phosphorus removal efficiency was gradually reduced with increasing the residence time in the anaerobic tank.