Treatment of Industrial Wastewater Using an Integrated Anaerobic Reactor and Fixed-Film Activated Sludge (IFAS) System

Wastewater reuse has become a common practice in many industries to manage water resources effectively. The objective of this research was to investigate the possibility of reusing treated wastewater from the Urmieh 2 industrial state an integrated approach combining industrial and agricultural water harvesting. In this study, a pilot-scale IFAS system was used for wastewater treatment, which included an anaerobic reactor. The effective parameters evaluated included efficiency in removing COD, BOD, TSS, pH and HRT. The adaptation of microorganisms in biofilm formation to reach a stable state in the IFAS occurred within a maximum of 35 days. After this period, no noticeable change in COD removal efficiency was observed. The optimal HRT for anaerobic reactor was 1 day with 4 hr of aerobic activity. The highest removal efficiencies of COD, BOD and TSS, respectively, were observed with HRTs of 2 days anaerobic and 8 hr aerobic 88.71%, 3 days anaerobic and 8 hr aerobic 92.11%, and 2 days anaerobic and 8 hr aerobic 97.90%. According to the Wilcox classification, the effluents from the process are categorized as medium-quality waters and are suitable for irrigation purposes. The output pH values indicate that the treated wastewater can also be used in agricultural applications.