With the rapid development and application of biochemical technology, the biogeochemical behaviour interaction between microbial and metal elements has become a research hotspot, especially the research about relationship between microbial and toxic metal elements. Shewanella is a facultative anaerobic iron-reducing bacterium. Studies have been conducted to investigate the reaction of Shewanella sp. with various heavy metals, including iron, arsenic, uranium, etc. Shewanella sp. can reduce, precipitate and even remove heavy metals, so it is widely used in sewage treatment. Yet, there are few articles discussing the interaction between Shewanella sp. and antimony currently, especially about antimonial smelting slag.

In this research, the antimonial smelting slag is reacted with Shewanella sp. over 10 days at circumneutral pH conditions. The changes in Eh, pH, dynamics and speciation of Sb and Fe are investigated at room temperature. The results are as follows: (1) A large amount of Fe³⁺ released from smelting slag is preferentially reduced to Fe²⁺ by Shewanella sp., and then precipitated as nano-Fe sulphides (e.g. FeS, FeS₂), the Fe²⁺ concentration first rose to the highest peak and then decreased to a constant after seven days; (2) The dissolved Fe³⁺ and Sb³⁺ are subjected to the redox reaction, and the Sb³⁺ is oxidized to the Sb⁵⁺. This process is only needed less than 24h. The presence of cerium oxide in a sterile control test indicates the presence of a redox reaction during the reaction, and (3) the total Sb concentration is reduced by the adsorption of iron or manganese (hydr)oxide dissolved in the solution from the smelting slag.

A supplementary experiment is done to further explore the relationship between Sb and Fe under the action of Shewanella sp.. The chemical reagents (K(SbO)C₄H₄O₆•1/2H₂O and KSb(OH)₆) were used to simulate slag and reacted with Shewanella sp., and Fe³⁺ was used as a control. When there was no iron element, the Sb was reduced, it was oxidized. This further illustrates that, although Shewanella sp. has a reducing ability for Sb and has great application prospects, when coexisting with iron, there are sequential reaction sequences and other complex reactions. This study provides a theoretical basis for the treatment of heavy metal pollution in the mine by Shewanella sp..