Novel green hybrid acidic-cyanide bioleaching applied for high recovery of precious and critical metals from spent light emitting diode lamps

摘要: Abstract The spent light emitting diode (LED) lamp is a new type of electronic waste contains the large amount valuable metals. In this study, novel green hybrid acidic-cyanide bioleaching process was developed for high efficiency recovery metals from LED lamps. LEDs were bio-pretreated using biogenic ferric produced by Acidithiobacillus ferrooxidans to efficiently harvest all base and heavy metals, 93% Sn, 94% Ni, 80% Cu, 68% Al, 60% Ga, 51% Pb, 46% Cr, 35% Fe leached. Then residue bioleached Bacillus megaterium (B. megaterium). Under optimum conditions (pH 7; glycine 2.5 g/L; L. methionine 10 g/L), 15 mg/L cyanide B. in short time 14 h. At g/L LED, under direct bioleaching, 47% gold extraction observed after 36 better performance suggests important role extracellular polymeric substances (EPS) continuous production CN-. Compared single with un-pretreated LEDs, amounts recovered through significantly high; Au, 91% Ag, 98% 87% 84% Ga leached 4 d. This study an approach efficient recycling that will result huge economic interest environmental performance.