Performance of a compartmentalized activated sludge (CAS) system treating a synthetic antibiotics industrial wastewater (SAW)

In this study, a 3-L compartmentalized activated sludge (CAS) system with 6 compartments was designed and fabricated. In the start-up stage, pre-acclimatized inoculums were added into the CAS and the system was operated under certain operating conditions until the system performance remained at a steady state. The effects of two process variables (mixed liquor volatile suspended solids (MLVSS) and influent chemical oxygen demand (CODin)) on the reactor performance were investigated and the process was modeled and analyzed using response surface methodology (RSM). From the results, the ratio of food to microorganism (F/M) was found to be the most important factor for the process control. Maximum removal efficiency (89%) was determined at a MLVSS and CODin of 4800 and 2000 mg/L, respectively. Kinetic coefficients (Y and Kd) were determined as 0.0815 g VSSproduced/g CODrem and 0.009 d−1, respectively. Biodegradation of Co-amoxiclav and ciprofloxacin were also investigated in the CAS system. The COD removal dropped from 29 to −18% after five turnovers (two days) for Co-amoxiclav. The process instability was also observed by a remarkable increase in effluent turbidity (>370 NTU) as a result of intensive biomass decomposition.