The images of mixed cell-iron oxide after the batch experiments are shown in Fig. 2. The macroscopic results showed the attachment
between bacteria and minerals. The adhesion of bacteria to
minerals might block the adsorption sites of As on the minerals.
Therefore, As adsorption might be impeded by bacteria due to
occupation of adsorption sites. In addition, no morphological
change in the iron oxides was observed after incubation with As
and bacteria, which is similar to the observation in cell-Mn oxide
oxidation by Jones et al (Jones et al., 2012). However, different
morphologies were detected by Muehe et al. during microbial
Fe(III) reduction, as revealed by the formation of secondary Fe
mineral products (Muehe et al., 2013). In the study of Jones et al., it
was observed that more As was adsorbed by d-MnO2 alone than by
the cell-d- MnO2 experiments (Jones et al., 2012).