Removal process and mechanism of hexavalent chromium by adsorption-coupled reduction with marine-derived Aspergillus niger mycelial pellets

• Published in: Chinese journal of chemical engineering 2022-09, Vol.49 (9), p.198-204
• Main Authors: Xu, Shanshan, Zhang, Qilei, Bai, Dongmei, Cai, Linian, Lu, Tao, Yao, Shanjing
• Format: Article
• Language: English
• Subjects: Adsorbent; Aspergillus niger; Cr(VI) removal; Mycelial pellets; Reduction
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/j.cjche.2021.10.002

[Display omitted] In order to remove hexavalent chromium (Cr(VI)) from solutions efficiently, the mycelial pellets with a marine-derived fungus Aspergillus niger as a biosorbent were prepared. The effects of removal process parameters such as solution pH, initial Cr(VI) concentration and biomass concentration on Cr(VI) removal process were investigated. The results showed that Cr(VI) removal rate up to 100% could be achieved under optimized conditions, which indicated the excellent Cr(VI) removal performance of the Aspergillus niger pellets. As a more important point, the Cr(VI) removal mechanism was studied, and the results revealed that Cr(VI) removal was achieved in the adsorption-coupled reduction process. A little of Cr(VI) was reduced to less toxic trivalent chromium (Cr(III)) in solution, while some was absorbed on the surface of mycelial pellets. Then they may be reduced on the surface or transferred into cells and then be reduced. The marine-derived A. niger mycelial pellets show properties of easy preparation and separation and cost effectiveness, which are potential biosorbent and reductant in the treatment of trace chromate containing wastewater.