Arsenic removal using bacteria immobilized on polyurethane foam in a packed bed bioreactor

Abstract

Arsenic contamination in groundwater is a cause of global concern. Bioremediation presents a viable alternative to conventional methods employed for arsenic treatment. This study investigated the use of bacteria immobilized on polyurethane foam (PUF) for arsenic remediation in a recirculating packed bed bioreactor. The effectiveness of Proteus alimentorum strain TY6 and Pseudomonas aeruginosa strain K7Pb for removal of As(III) and As(V) was evaluated. Concentrations of arsenic ranged from 250 μg/L to 50 mg/L at varying flow rates. The removal efficiency of TY6 varied from 0.45 % to 99.50 % for As(III) and 0.75 % to 98.40 % for As(V). For K7Pb, the efficiency ranged from 0.79 % to 99.30 % for As(III) and 0.80 % to 99.40 % for As(V). Bacteria immobilized on PUF were found to be highly efficient in arsenic removal. The removal efficacy was found to be above 65 % even at a concentration of 50 mg/L for both bacteria. Both bacterial strains also demonstrated significant potential for arsenic biotransformation. TY6 only oxidized As(III) to As(V), whereas K7Pb only reduced As(V) to As(III). The outcomes indicated that both strains possessed substantial potential for arsenic remediation.