Environmentally sustainable and cost-effective bioleaching of aluminum from low-grade bauxite ore using marine-derived Aspergillus niger

Autor(es)

Shah, Syed Sikandar ^{[1, 2]} ; Palmieri, Mauricio Cesar ^[3] ; Pombeiro Sponchiado, Sandra Regina ^[1] ; Bevilaqua, Denise ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ, Inst Chem Araraquara, UNESP, Dept Biochem & Chem Technol, BR-14800060 Sao Paulo, SP - Brazil

^[2] Bacha Khan Univ, Dept Chem, Charsadda, Kpk - Pakistan

^[3] Itatijuca Biotech, BR-05508000 Sao Paulo, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: HYDROMETALLURGY; v. 195, AUG 2020.
• Citações Web of Science: 2

Resumo

In this study, an economical and sustainable bio-hydrometallurgical route was evaluated for the recovery of aluminum from low-grade bauxite using the marine-derived fungus Aspergillus niger. Firstly, four different solid media were tested for high-yield spore production. Organic acid production capacity by A. niger was also evaluated in a medium supplemented with glucose or low-cost molasses as a carbon source using fungal spores or pellets as inoculum. The concentrations of the produced organic acids were determined by High-Performance Liquid Chromatography (HPLC). The results showed that oat-agar can be used as an inexpensive solid medium for greater fungal sporulation, while the liquid medium supplemented with molasses as a low-cost carbon source can be used for higher organic acids production. Among the conditions tested, A. niger spore inoculum showed the highest yield of the total produced organic acids (122.40 g L-1 or 81.6% (grams of sucrose used per grams of total acid) and also the highest (1.02 +/- 0.02 g L-1 h(-1)) acids production rate using molasses as an inexpensive carbon source. This cultivation condition was selected for the bioleaching studies with low-grade bauxite. Among the three different bioleaching methods tested, the direct two-steps bioleaching process resulted in higher aluminum leaching (91.2%) compared to indirect (84.8%) and direct one-step (82.8%) bioleaching process. According to the results obtained using marine-derived A. niger under the established culture conditions, proved to be an eco-friendly and cost-effective way for aluminum recovery from low-grade bauxite ore and has the potential to be adopted on a pilot scale. (AU)

• Processo FAPESP: 15/24757-9 - Avaliação da técnica LIBS para determinação de Ca, K, P e N em novos fertilizantes inteligentes e sustentáveis
• Beneficiário: Edilene Cristina Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular