Bioremediation of Congo red in an anaerobic moving bed bioreactor: Process optimization and kinetic modeling

Abstract

The Lysinibacillus fusiformis immobilized polyurethane foam–polypropylene bio carrier was used as support media in an anaerobic moving bed bioreactor to evaluate the biodegradation of Congo red (CR) dye. The process variables like CR dye concentration (20–100 mg/L), bio carrier filling ratio (BFR) (20–70%), and agitation speed (40–100 RPM) were optimized using response surface methodology and obtained to be 60 mg/L, 45%, and 70 RPM, respectively. Moreover, the AnMBBR was continuously operated at optimized conditions for 120 days by varying the feed flow rate in the range of 10 to 60 mL/min. The maximum elimination capacity and removal efficiency were found as 21.0 mg/L. d and 87.33%, respectively. The high regression coefficient (R2 = 0.99) shows the efficacy of the modified Stover–Kincannon (MSK) model to predict the experimental value accurately. The kinetic parameters were evaluated to be: Umax: 0.21 g/L. d, KB: 0.23 g/L. d. © 2021 Elsevier Ltd