Simultaneous oxidization-adsorption for arsenic and antimony by biological Fe-Mn binary oxides (BFMO): The efficiencies and mechanism

Here, a novel manganese oxidizing bacterium Morganella Morganii MnOx-1 was applied to synthesize biological iron-manganese oxides (BFMO) to simultaneously oxidize and adsorb As and Sb. The oxidization rates of As(III) and Sb(III) by BFMO were 74.13% and 51.85%, which were 1.43 and 1.30 times of that by biological manganese oxides (BMO), respectively. Moreover, the simultaneous removal rates of As(III), As(V), Sb(III) and Sb(V) (100 mg/L of each) by BFMO with the stain MnOx-1 were 87.05%, 94.23%, 79.65% and 84.33% in 7 days, and 80.26%, 99.32%, 82.97% and 88.50% in 28 days, respectively. In addition, BMO contributed to oxidize As(III) and Sb(III), and FeOOH was mainly responsible for adsorption by complexing with the metalloids in the simultaneous removal of As and Sb. The function groups on the surface of BFMO, such as -OH, C-O, C-O, C-C, etc. were also involved the adsorption processes. Our results have important implications for understanding the transformations of As and Sb intermediating by manganese oxidizing bacteria, and develop an environmental-friendly method for simultaneously removing As and Sb pollutants in water.