title: Development of two-step process for enhanced biorecovery of Cu-Zn-Ni from computer printed circuit boards.
abstract: Metal pollution due to the huge electronic waste (E-waste) accumulation is widespread across the globe. Extraction of copper, zinc and nickel from computer printed circuit boards (c-PCB) with a two-step bleaching process using ferric sulphate generated by Leptospirillum ferriphilum dominated consortium and the factors influencing the process were investigated in the present study. The studied factors with 10 g/L pulp density showed that pH 2.0 was optimum which resulted in 87.50-97.80% Cu-Zn-Ni extraction. Pre-treatment of PCB powder with acidified distilled water and NaCl solution showed 3.80-7.98% increase in metal extraction corresponding to 94.08% Cu, 99.80% Zn and 97.99% Ni extraction. Particle size of 75 μm for Cu and Zn while 1680 μm for Ni showed 2-folds increase in metal extraction, giving 97.35-99.80% Cu-Zn-Ni extraction in 2-6 days of reaction time. Whereas; 2.76-3.12 folds increase in Cu and Zn extraction was observed with the addition of 0.1% chelating agents. When the studies were carried out with high pulp density, ferric iron concentration of 16.57 g/L was found to be optimum for metal extraction from 75 g/L c-PCB and c-PCB addition in multiple installments resulted in 8.81-26.35% increase in metal extraction compared to single addition. The studied factors can be implemented for the scale-up aimed at faster recovery of multimetals from E-waste and thereby providing a secondary source of metal in an eco-friendly manner.
authors: Department of Microbiology and Biotechnology, School of Sciences, Gujarat University, Ahmedabad 380 009, Gujarat, India.
authors: Monal B
authors: MB
authors: Shah
authors: Department of Microbiology and Biotechnology, School of Sciences, Gujarat University, Ahmedabad 380 009, Gujarat, India.
authors: Devayani R
authors: DR
authors: Tipre
authors: Department of Microbiology and Biotechnology, School of Sciences, Gujarat University, Ahmedabad 380 009, Gujarat, India.
authors: Mamta S
authors: MS
authors: Purohit
authors: Department of Microbiology and Biotechnology, School of Sciences, Gujarat University, Ahmedabad 380 009, Gujarat, India. Electronic address: shaileshrdave@yahoo.co.in.
authors: Shailesh R
authors: SR
authors: Dave
mesh_terms: D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D002614:Chelating Agents; D003201:Computers; D003300:Copper / Q000737:chemistry / Q000302:isolation & purification*; D059029:Electronic Waste; D005290:Ferric Compounds / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009532:Nickel / Q000737:chemistry / Q000302:isolation & purification*; D010316:Particle Size; D015032:Zinc / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D002614:Chelating Agents; D005290:Ferric Compounds; C024823:ferric sulfate; D003300:Copper; D009532:Nickel; D015032:Zinc
keywords: Chelating agent; Computer printed circuit board; High pulp density; Leptospirillum ferriphilum; Pre-treatment; Two-step bioleaching