Performance comparison of conventional biological treatment process and membrane bioreactor treating common industrial effluent

Industrial effluent is challenging for wastewater treatment plants due to its complexity, toxicity and variable composition. This study aimed to evaluate the efficiency of industrial wastewater treatment between a lab-scale membrane bioreactor (MBR) and a full-scale anoxic/oxic (A/O) process. The wastewater used was after primary sedimentation tank, which involved lime or ferric coagulant. The results showed that the treated water quality from both systems was satisfied the national effluent standard for wastewater (column B of QCVN 40-MT:2011/BTNMT). The effluent from A/O process contained 74 ± 11 mg/L of COD, 8.3 ± 1.9 mg/L of TN, 1.6 ± 0.6 mg/L of TP, and 201± 38 Pt-Co of color. Meanwhile, the concentrations of COD, TN, TP, and color in the effluent of MBR system were 88 ± 21, 23.2 ± 4.6, 0.3 ± 0.2 mg/L, and 220 ± 98 Pt-Co, respectively. The removal rates of COD, TN, TP and color of anoxic/oxic process were 234 ± 119, 16 ± 3, 0.3 ± 0.2 mg/L.day, 213 ± 58 Pt-Co/L.day, respectively. The removal rates of COD, TN, TP, and color in MBR system were 1.6, 1.3, 10.3, and 2.1 times higher than those in the A/O process, respectively. Although the A/O process in industrial zones performed well, the MBR system demonstrated higher removal rates, particularly for nutrient removal. Besides, MBR systems offer several advantages, including reduced excess sludge production and less space requirements compared to A/O process. In general, MBR offers a promising solution for industrial wastewater treatment, with strong potential for application in industrial zones.