Bacterially-assisted recovery of cadmium and nickel as their metal sulfide nanoparticles from spent Ni–Cd battery via hydrometallurgical route. (1st May 2020)

• Record Type: Journal Article
• Authors: Paul, Siddhartha; Shakya, Arvind Kumar; Ghosh, Pranab Kumar
• Is Part Of: Journal of environmental management. Volume 261(2020)
• Publication Date: 2020-05-01
• Subjects: Cadmium -- Nickel -- Nanoparticle -- Bacteria -- Battery; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2020.110113
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: Soaring demand for technology metals (e.g., Cd, Ni) and its ever-depleting primary resources ask for alternative recovery from secondary sources. Ni–Cd battery is one such source that can abridge the gap between demand and supply of such metals. Biogenic recovery, being environmentally benign, is explored for Cd and Ni recovery to manage the menace of spent Ni–Cd battery. Studies with 20, 40 and 60 mg/L Cd 2+ initial concentrations in batch mode (in triplicates) at pH 7.0 ± 0.2, 30 ± 0.5 °C and 120 rpm were conducted using sulfate-reducing bacteria for 10 days. Analysis of extracellular polymeric substance revealed that protein secretion was enhanced, thereby forming Cd-EPS binding. Biosolids were collected and freeze-dried for morphological analysis viz. FESEM/EDX, PXRD and TEM, which revealed the formation of CdS nanoparticles (JCPDS card #00-042-1411) in range of 2–6 nm. Similarly, combined effect with 5, 10 and 20 mg/L Ni 2+ at 20 mg/L Cd 2+ were also investigated. Furthermore, to test the efficacy for real field application, spent Ni–Cd battery was dismantled and its powder was characterized, digested with concentrated HCl at 70 °C and was fed in batch mode after cooling, wherein nanoparticles of Ni and Cd sulfides were formed that has potential as semi-conducting material. Graphical abstract: Image 1 Highlights: First report on bacterially-assisted recovery of Cd from waste Ni–Cd battery. Bioavailability of Cd was bacterially reduced and immobilized as CdS nanoparticle. PN secretion was enhanced, enabling Cd-EPS binding to protect the bacteria. PXRD and TEM pictured the biosynthesis of 2–6 nm crystals of hawleyite. Metal was bacterially recovered from digested Ni–Cd battery liquor in benign way.