The present study aims to investigate the possibility of domestic wastewater treatment using biological system combined with chemical-physical processes, including Upflow Sludge Blanket Filtration (USBF) technology and PolyAluminium Chloride (PAC). Experimental results showed that the added PAC content plays an essential role in improving the treatment efficiency and reached National Technical Regulation on domestic wastewater QCVN 14:2008/BTNMT (Column A). With Jar-test results, the optimal pH of 7.0 and the PAC dosage of 170 mg/L were recorded with the highest removal efficiencies for suspended solids and organic matter. In the modified USBF bioreactor, the findings illustrated the pollutant removal efficiencies such as Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (COD), and Suspended Solids (SS) were equal to 96.2 ± 1.4%, 85.8 ± 4.4% and 99.3 ± 2.1%, respectively. The parameters of BOD5 and SS met QCVN 14:2008/BTNMT - Column A. In the future, this advanced filtration technology can be helpful for wastewater reclamation and reuse to cope with water scarcity.

Selecting wastewater treatment technology is not an easy matter. In this study, TOPSIS and AHP methods are used to support decision-making in choosing a wastewater treatment alternative for Poong In Vina factory. A total of 9 criteria belonging to 3 groups of economic, social - technical and environmental issues were used to select an alternative. The results of TOPSIS and AHP analysis showed that aerobic biotechnology integrated with membrane bioreactor technology is the optimal solution. The outcomes of this study will help the company in choosing the best option among these technologies. Furthermore, it will provide an insight for relevant stakeholders such as engineers, manufacturers and other ogranizations for making decisions.