Cr(VI) bio-treatment has attracted a substantial amount of interest due to its cost effectiveness and environmental friendliness. However, the slow Cr(VI) bio-reduction rate and the formed organo-Cr(III) in solution are bottlenecks for biotechnology application. In this study, a novel strain, Acinetobacter sp. HK-1, capable of reducing Cr(VI) and immobilising Cr(III) was isolated. Under optimal conditions, the Cr(VI) reduction rate could reach 3.82 mg h-1 g cell-1. To improve the Cr(VI) reduction rate, two quinone/graphene oxide composites (Q-GOs) were first prepared via a one-step covalent chemical reaction. The results showed that 2-amino-3-chloro-1,4-naphthoquinone-GO (NQ-GO) exhibited a better catalytic performance in Cr(VI) reduction compared to 2-aminoanthraquinone-GO. Specifically, in the presence of 50 mg L-1 NQ-GO, a Cr(VI) removal rate of 190 mg h-1 g cell-1, which was the highest rate obtained, was achieved. The increased Cr(VI) reduction rate is mainly the result of NQ-GO significantly increasing the Cr(VI) reduction activity of cell membrane proteins containing dominant Cr(VI) reductases. X-ray photoelectron spectroscopy analysis found that Cr(VI) was reduced to insoluble Cr(III), which was immobilised by glycolipids secreted by strain HK-1.

Cr(VI) reduction by Acinetobacter sp. HK-1 with the assistance of a novel quinone/graphene oxide composite

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.