| Abstract | The qualitative shocks were studied on the continuous flow completely mixed activated sludge (CMAS) process with constant recycle sludge concentration (XR, 7000 mg/l ) and hydraulic recycle ratio, a , 0.3. The soft drink bottling wastewater was used as the The qualitative shocks were studied on the continuous flow completely mixed activated sludge (CMAS) process with constant recycle sludge concentration (XR, 7000 mg/l ) and hydraulic recycle ratio, a , 0.3. The soft drink bottling wastewater was used as the substrated and initial COD
concentration was maintained at 1000 mg/l . The types of shocks were classified as pH (3.0, 4.0, 9.7, 10.4), temperature (33,46°C) , potassium cyanide (KCN, 50 mg/ l) and phenol (185 mg/l) . The dilution rates were
maintained at 1/4 hr-1 for the shock load of pH and temperature, 1/4 and and 1/8 hr-1 for KCN and 1/4, 1/8, 1/16 hr-1 for phenol. Before the shocks, pH and temperature were maintained as 6.8-7.2 and 23-24°C respectively. It was found that the unit could handle pH level of 4.0 to 10.4.
At pH 3.0, leakage of substrate, decrease of biological solid concentration and change of microbial population (bacteria-protozoan) to filamentous
fungi were occurred. For temgerature shock load, the unit could still handle up to 33°C, but for 46 C, 14 hours for recovering was needed. For the KCN and phenol shocks, the lower dilution rates which were used in the present study, could response more successfully. and initial COD concentration was maintained at 1000 mg/l . The types of shocks were clas
sified as pH (3.0, 4.0, 9.7, 10.4), temperature (33,46°C) , potassium cyanide (KCN, 50 mg/ l) and phenol (185 mg/l) . The dilution rates were
maintained at 1/4 hr-1 for the shock load of pH and temperature, 1/4 and and 1/8 hr-1 for KCN and 1/4, 1/8, 1/16 hr-1 for phenol. Before the shocks, pH and temperature were maintained as 6.8-7.2 and 23-24°C respectively. It was found that the unit could handle pH level of 4.0 to 10.4. At pH 3.0, leakage of substrate, decrease of biological solid concentration and change of microbial population (bacteria-protozoan) to filamentous fungi were occurred. For temperature shock load, the unit could still handle up to 33°C, but for 46 C, 14 hours for recovering was needed. For the KCN and phenol shocks, the lower dilution rates which were used in the present study, could response more successfully. |