Removal of selenium from river water by a microbial community enhanced with Enterobacter taylorae in organic carbon coated sand columns

Discovering an effective means to remove selenium (Se) from Se-contaminated water is fundamental in minimizing environmental contamination and ensuring wildlife protection. In this study, Enterobacter taylorae attached to tryptic soy agar (TSA) coatings was used in sand columns to remove Se from a natural river water. During 80 days of the experiment, E. taylorae and indigenous Se(VI) reducers in the water used organic carbon coatings to effectively reduce Se(VI) to Se(0). About 95% and 70% of the influent Se (469 μg/L) was reduced to Se(0), respectively, in the columns with and without E. taylorae and 94-98% of the newly formed Se(0) was trapped in the columns. Analysis of Se species in effluent at the end of the experiment revealed that organic Se from the columns with E. taylorae was similar to that in influent (0.567 μg/L). This study indicates that using organic coatings attached with Se(VI) reducers in a biotreatment system may be a potentially feasible method to remove Se from Se-contaminated water in field.