Self-regenerable bio-hybrid with biogenic ferrous sulfide nanoparticles for treating high-concentration chromium-containing wastewater. (1st November 2021)

• Record Type: Journal Article
• Authors: Fu, Xian-Zhong; Wu, Jie; Cui, Shuo; Wang, Xue-Meng; Liu, Hou-Qi; He, Ru-Li; Yang, Cheng; Deng, Xin; Tan, Zhou-Liang; Li, Wen-Wei
• Is Part Of: Water research. Volume 206(2021)
• Publication Date: 2021-11-01
• Subjects: Heavy metal -- Biogenic FeS nanoparticles -- Extracellular electron transfer -- Regeneration; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2021.117731
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: ● Bio-hybrid consisting of living cells and self-assembled bio-FeS was developed;. ● The cells drive efficient regeneration of bio-FeS for enhanced Cr reduction;. ● Bio-FeS shell serves as a protective layer to improve the bacterial Cr tolerance;. ● Bio-FeS forms a transmembrane electron channel to enhance Cr reduction;. ● The bio-hybrid is efficient for cyclic treatment real electroplating wastewater. Abstract: Biogenic ferrous sulfide nanoparticles (bio-FeS) as low-cost and green-synthesized nanomaterial are promising for heavy metals removal, but the need for complicated extraction, storage processes and the production of iron sludge still restrict their practical application. Here, a self-regenerable bio-hybrid consisting of bacterial cells and self-assembled bio-FeS was developed to efficiently remove chromium (Cr(VI)). A dense layer of bio-FeS was distributed on the cell surface and in the periplasmic space of Shewanella oneidensis MR-1, endowing the bacterium with good Cr(VI) tolerance and unusual activity for bio-FeS-mediated Cr(VI) reduction. An artificial transmembrane electron channel was constituted by the bio-FeS to facilitate extracellular electron pumping, enabling efficient regeneration of extracellular bio-FeS for continuous Cr(VI) reduction. The bio-hybrid maintained high activity within three consecutive treatment-regeneration cycles for treating both simulated Cr(VI)-containing wastewater (50 mg/L) and real electroplating wastewater. Importantly, its activity can be facilely and fully restored through bio-FeS re-synthesis or regeneration with replenished fresh bacteria. Overall, the bio-hybrid merges the self-regeneration ability of bacteria with high activity of bio-FeS, opening a promising new avenue for sustainable treatment of heavy metal- containing wastewater. Graphical abstract: Image, graphical abstract