Leaching of metals from printed circuit board powder by an Aspergillus niger culture supernatant and hydrogen peroxide

Abstract

Removal of chemical coating of PCB powder using 0.1 M sodium hydroxide solution.

Bioleaching of heavy metals from printed circuit board (PCB) by Streptomyces albidoflavus TN10 isolated from insect nest

“…2a, c). Similar findings were reported by Jadhav et al (2016) that the maximum level of zinc extraction is 98% by Aspergillus niger supernatant with 0.1 M of NaOH. Chen and Huang (2014) reported recovery of copper 65% and nickel 100% in PCB wastewater sludge by S. thermosulfidooxidans.…”

“…PCBs were transferred in 10-M NaOH solution and left undisturbed for 48 h. Then, PCBs were taken out and washed under running tap water to remove the solder. The treated PCBs were kept in tray dryer for 40 min and finally sieved for fine powder with 120-µm pore size for analysis and bioleaching (Jadhav et al 2016).…”

“…The flasks were kept in a rotary shaker at 110 rpm for 120 h. Then, the sample was drawn aseptically at every 24 h. Cells were separated by centrifugation at 10,000 rpm for 20 min and the cell-free supernatant was collected in clean tubes and used for analysis. Bioleaching of heavy metals from the crude PCB was determined by ICP-MS analysis (Agilent 7700X ICP-MS instrument (Model#-G3281A) The percentage of heavy metals accumulation was calculated using the formula (Jadhav et al 2016). % heavy metal extraction = Initial metal content − metal content after leaching/initial metal content × 100.…”

Colonization, penetration and transformation of manganese oxide nodules by Aspergillus niger

“…Manganese nodule resources represent a wealth of metals with wide ranging uses as both raw materials for infrastructure, such as Cu, Ni and Mn, and critical metals with application in advanced electronic and energy technologies, including Co, Nb and several REE (Hein et al, 2013;Vidal et al, 2017). Bioprocessing strategies using bacteria and fungi have received renewed attention in this context as efficient low-cost and low-carbon alternatives to traditional metal processing approaches (Strasser et al, 1994;Mulligan and Galvez-Cloutier, 2000;Mulligan et al, 2004;Biswas et al, 2013;Zeng et al, 2015;Jadhav et al, 2016;Liang and Gadd, 2017). In the light of these trends, we have investigated some fundamental interactions between manganese nodules and Aspergillus niger, a geoactive species considered to be particularly well suited to such applications.…”

“…The bioweathering capabilities of geoactive fungal species also suggest that they are suited to certain metal bioprocessing applications (Gadd, 2010). Several studies have examined the ability of various species to leach metals from a variety of substrates including low-grade ores and residues (Mulligan and Galvez-Cloutier, 2000;Mulligan et al, 2004;Biswas et al, 2013), fly ash (Wu and Ting, 2006;Xu and Ting, 2009;Xu et al, 2014) and electronic wastes (Jadhav et al, 2016). Additionally, the capabilities of organic acids have also been studied for application in abiotic leaching processes (Strasser et al, 1994;Astuti et al, 2016).…”