Municipal wastewater treatment using an integrated system of aerobic granular sludge, membrane, and ultraviolet processes for reuse in irrigation

This study investigates treatment of municipal wastewater by using an integrated system involving aerobic granular sludge (AGS) process followed by two different membrane processes (microfiltration (MF) or ultrafiltration (UF)) and ultraviolet (UV) process for reuse in irrigation. Two different integrated systems (AGS-MF-UV and AGS-UF-UV systems) were compared in terms of treatment performance, filtration performance, and cost analysis. Similar removal efficiencies were achieved for the AGS–MF–UV and AGS–UF–UV systems in terms of chemical oxygen demand (> 90%), total nitrogen (> 75%), and total phosphorus (> 74%). Since UF had superior pathogen removal performance compared to MF, UV process may not be necessary after the UF system. However, the operating cost of the AGS-UF system (0.223 €/m³) was found more expensive than that of AGS-MF-UV system (0.203 €/m³). The results of the cost analysis demonstrated that AGS-MF-UV system can be considered as a more economically feasible option in comparison with AGS-UF-UV system for treatment of municipal wastewater. The reclaimed water from AGS-MF-UV and AGS-UF-UV systems met the irrigation water requirements for Environmental Protection Agency (EPA) and European Union (EU) standards.