Investigation of textile dyeing effluent using activated sludge system to assess the removal efficiency

In this current work, the performance of an aerobic granular sludge (AGS) for real textile wastewater was investigated based on system operational parameters evaluation. The study was performed for 90 days, and sampling was done once a week in which textile dyeing effluent from the textile mill was collected and subjected to laboratory-scale treatment. The samples from the inlet, the outlet of the wastewater plant, and within the bioreactor were collected at various concentrations of mixed liquid suspended solids (MLSS), and hydraulic retention remained the same in the investigated period of 53 h. The objective of this study was to analyze the AGS system performance assessment by evaluating the effect of different MLSS concentrations on chemical oxygen demand (COD), total suspended solids (TSS), and oil/grease removal from real-based textile water. The results showed that removal of organic material from the process water increases with an increase in MLSS concentration in the bioreactor and gradually shifts removal of COD from 91.2% to 94.5%. As the concentration of microorganisms in the reactor (aeration tank) increases, the degradation of waste organics in the wastewater increases as well. Moreover, the % removal of TSS (83.5% to 98%) and removal of oil/grease (62.5% to 76.4%) were also increased. These results ultimately suggest that the utilization of an activated sludge system can effectively treat complex and highly polluted denim textile wastewater to avoid secondary pollution posed by this industry. PRACTITIONER POINTS: The effectiveness of aerobic granular sludge was investigated for industrial textile effluent. The increase in MLSS results in increase of % COD removal efficiency to 94.5%. The AGS system can efficiently treat complicated and highly contaminated textile wastewater.