Bioconversion of high‐concentration chelated Cd to nano‐CdS photocatalyst by sulfate‐reducing bacteria. Issue 11 (12th June 2020)

• Record Type: Journal Article
• Authors: Liu, Yali; Wang, Jie; Li, Panyu; Xie, Yi; Xie, Hongyang; Xie, Tonghui; Zhang, Yongkui
• Is Part Of: Journal of chemical technology & biotechnology. Volume 95:Issue 11(2020)
• Page Start: 3003
• Page End: 3011
• Publication Date: 2020-06-12
• Subjects: chelated heavy metal -- sulfate‐reducing bacteria -- bioconversion -- EDTA‐Cd -- cadmium sulfide; Biotechnology -- Periodicals; Chemistry, Technical -- Periodicals; Chemical engineering -- Periodicals; Industries -- Environmental aspects -- Periodicals; 660
• DOI: 10.1002/jctb.6461
• Languages: English
• ISSNs: 0268-2575

Abstract

Abstract: BACKGROUND: Chelated heavy metals have received wide attention due to their adverse effects and difficulty in removal. Sulfate‐reducing bacteria (SRB) inducing heavy metals to produce metal sulfide precipitation is an attractive bioremediation technology. It not only reduces heavy metal pollution but also transforms metal contaminants into value‐added products. RESULTS: The stable ethylenediaminetetraacetic acid (EDTA)‐Cd was effectively removed and converted to CdS nanoparticles by SRB. The SRB could resist high concentrations of EDTA‐Cd up to 2.5 mmol L −1, while no growth was observed at 1.0 mmol L −1 of free cadmium ions. The bio‐removal efficiencies of EDTA‐Cd at initial concentrations of 0.5, 1.0, 1.5, 2.0 and 2.5 mmol L −1 were 100%, 100%, 95.89%, 67.63% and 26.66%, respectively. Meanwhile, the reduction efficiencies of sulfate by SRB were 45.6% to 24.9%. The products were cadmium sulfide nanoparticles with a mean particle size of 40–80 nm, which were confirmed by X‐ray diffraction and scanning electron microscopy analyses. Furthermore, the cadmium sulfide product exhibited a good photocatalytic performance, and the removal efficiency of rhodamine B (RhB) reached 97% within 2 h. CONCLUSION: This study demonstrated that EDTA‐Cd could be effectively removed by SRB and recovered in the form of high‐value cadmium sulfide photocatalyst. The proposed strategy may provide a new solution for the recycling of chelated heavy metal ions. © 2020 Society of Chemical Industry