Use of adapted Aspergillus niger in the bioleaching of spent refinery processing catalyst

A novel sequential process of bioleaching and chemical leaching for dissolving Ni, V, and Mo from spent petroleum refinery catalyst

“…Bioleaching has been developed as a novel approach to recover metals from spent refinery catalyst (Amiri et al, 2011;Beolchini et al, 2010;Gholami et al, 2011Gholami et al, , 2012Pradhan et al, 2010;Santhiya and Ting, 2006). Bioleaching is based on the ability of some bacteria and fungi to transform solid compounds to extractable entities (Brierley, 2008;Elzeky and Attia, 1995).…”

Processing of spent NiMo and CoMo/Al2O3 catalysts via fusion with KHSO4

“…), but also on high yields on metals recovery or selective recovery of a specific element. Among these new processes, attention has been attracted to bio-hydrometallurgical routes for processing spent HDR catalysts since they can be performed under very mild experimental conditions, offering low cost and energy requirements, are environmentally safe and present a good operational flexibility [14,15]. Aspergillus niger is one of the most used microorganisms.…”

Biologically Induced Mobilization of Arsenic Adsorbed onto Amorphous Ferric Oxyhydroxides in Aqueous Solution During Fungal Cultivation

“…It has been reported, however, that oxalate acid production is highly effective even in the 5 to 8 pH range (Ruijter et al 1999), which correspond to media pH after the second cultivation day. Strains of A. niger are commonly applied in commercial organic acid production (Magnuson and Lasure 2004), especially for citrate and oxalate produced to maximum concentration of 200 mmol.L −1 in similarly designed experiments (Santhiya and Ting 2006). Therefore, we conclude here that the As release from FeOx is significantly enhanced by microbial organic acid production or competition of metabolites with arsenic for sorption positions on the FeOx surfaces, rather than by acidic FeOx dissolution.…”