Optimization of Biological Treatment of an Industrial Wastewater in an Intermittent Aeration Sequencing Batch Reactor

In this paper, the simultaneous removal of carbon and nutrients (nitrogen and phosphorus) from Faraman’s industrial wastewater (FIW) in a time-based sequencing batch reactor (SBR) was investigated. The experiments were conducted based on a central composite design (CCD) and analyzed using the response surface methodology (RSM). Reaction and aeration times were selected for the purposes of analyzing, modeling, and optimizing the process. Nine dependent parameters were monitored as process responses. The region of exploration for the process was taken as the area enclosed by the boundaries of reaction time (12-36 h) and aeration time (40-60 min/h). Reaction time was found to be the most effective variable and showed a decreasing impact on the total chemical oxygen demand (TCOD), slowly-biodegradable chemical oxygen demand (sbCOD), total nitrogen (TN), and total phosphorus (TP) removal efficiencies. The optimum operating conditions were determined in the range of 12 to 16 h for the reaction time and 40 to 60 min/h for the aeration time.