Evaluation of chromium removal efficiency at varying operating conditions of a novel bioelectrochemical system.

The assessment of chromium removal efficiency (CRE) was studied using experimental trials with variations in operating conditions for evaluating performance efficiency of the Bioelectrochemical system (BES). During the study, maximum CRE of 88.36 ± 8.16% was obtained at cathode pH 2 ± 0.1 from the varied cathode pH (pH 1, 2, 3, 4, 5, 6, 7). With varying reactor temperatures from 25 to 45 °C (25, 30, 35, 40, 45 °C), BES resulted in maximum CRE of 85.93 ± 9.62% at 40 °C. CRE increased from 78.50 ± 5.24 to 88.66 ± 8.40% with an increase in substrate concentration from 500 to 2000 mg/L chemical oxygen demand (COD). CRE decreased from 95.9 ± 2.9 to 89.56 ± 1.74% with an increase in initial chromium concentration from 10 to 100 mg/L. Correlation analysis revealed a positive correlation with COD reduction, COD, and temperature, whereas a negative correlation was observed for pH and initial chromium concentration.