Biodegradation of Congo red dye in a moving bed biofilm reactor: Performance evaluation and kinetic modeling

• DOI: 10.1016/j.biortech.2020.122811
• Publication Date: 2020-01-21T01:38:43Z
• Authors: Ravi Kumar Sonwani; Ganesh Swain; Balendu Shekhar Giri; Ram Sharan Singh; Birendra Nath Rai
• Keywords: Congo red; Central composite design

The biodegradation of Congo red dye was performed using polyurethane foam-polypropylene immobilized Bacillus sp. MH587030.1 in a moving bed biofilm reactor (MBBR). The central composite design (CCD) based response surface methodology (RSM) was used to optimize the process parameters; pH, Congo red concentration, and media filling ratio, and optimum conditions were observed to be 7.0, 50 mg/L, and 45%, respectively in batch MBBR. At optimum condition, MBBR was operated in continuous mode at different flow rates (25-100 mL/h) over a period of 564 h. The maximum removal efficiency (RE) and elimination capacity (EC) were obtained as 95.7% and 57.6 mg/L·day, respectively under steady-state. The kinetics of Congo red biodegradation at various flow rates were evaluated by a modified Stover-Kincannon model, and kinetic constants; KB and Umax were found to be 0.253 g/L·day and 0.263 g/L·day, respectively.