Behavior and Mechanisms of Antimony Precipitation from Wastewater by Sulfate-Reducing Bacteria <i>Desulfovibrio desulfuricans</i>
Fan Zhuang,
Xiaowu Xiang,
Jin Hu,
Jing Xiong,
Teng Zhang,
Lei Zhou,
Guoping Jiang,
Min Zhang,
Zhenghua Liu,
Huaqun Yin,
Ling Xia,
Ibrahim Ahmed Ibrahim Mahmoud,
Delong Meng
Affiliations
Fan Zhuang
Key Laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Xiaowu Xiang
Dongkou County Agricultural Bureau, Shaoyang 422300, China
Jin Hu
Key Laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Jing Xiong
Key Laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Teng Zhang
Key Laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Lei Zhou
Beijing Research Institute of Chemical Engineering and Metallurgy, Beijing 101148, China
Guoping Jiang
Beijing Research Institute of Chemical Engineering and Metallurgy, Beijing 101148, China
Min Zhang
Key Laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Zhenghua Liu
Key Laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Huaqun Yin
Key Laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Ling Xia
Hubei Key Laboratory of Mineral Resources Processing and Environment, School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070, China
Ibrahim Ahmed Ibrahim Mahmoud
Central Metallurgical Research and Development Institute, Cairo 11421, Egypt
Delong Meng
Key Laboratory of Biometallurgy, Ministry of Education, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
The development of the non-ferrous metal industry is generating increasingly large quantities of wastewater containing heavy metals (e.g., Sb). The precipitation of heavy metals by microorganisms involves complex mechanisms that require further investigation to optimize bioremediation technologies. In this study, we employed a sulfate-reducing bacteria (SRB) strain Desulfovibrio desulfuricans CSU_dl to treat the antimony (Sb)-containing wastewater; the behavior of Sb and mechanisms underlying precipitation were investigated by characterizing the precipitates. The results showed that the abiotic factors constraining SRB bacterial growth greatly affect Sb forms and precipitation. For instance, Sb precipitation maximumly occurred at pH 6 and 7, or C:N ratio of 10:1 and 40:3 for Sb(III) and Sb(V), respectively, resulting in a maximum Sb removal rate of 94%. Interestingly, we found that substantial antimonate and antimonite were adsorbed on the SRB cell surface, indicating that cell surface is a critical reaction site of Sb transformation and precipitation. Sb was adsorbed to the cell surface by C-C and C=O groups, and was further precipitated by forming Sb2S3 and Sb2S5 or was coprecipitated with the P-containing group. Partial Sb(V) reduction was also observed on the SRB cell surface. These results provided a deep insight into the Sb bio-transformation and were an advancement with respect to understanding bioremediation of Sb-contaminated wastewater.
