Biogenic nanopalladium production by self-immobilized granular biomass: Application for contaminant remediation

• Published in: Water research (Oxford) Vol. 65; pp. 395 - 401
• Main Authors: SUJA, E, NANCHARAIAH, Y. V, VENUGOPALAN, V. P
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier 15-11-2014
• Subjects: Applied sciences; Biological and medical sciences; Biological treatment of sewage sludges and wastes; Biomass; Biotechnology; Catalysis; Chromium - chemistry; Environment and pollution; Environmental Pollutants - chemistry; Environmental Restoration and Remediation; Exact sciences and technology; Fermentation; Fundamental and applied biological sciences. Psychology; General treatment and storage processes; Granular materials; Granules; Hydrogen - metabolism; Industrial applications and implications. Economical aspects; Metal Nanoparticles; Microbial Consortia; Microorganisms; Microscopy, Electron, Scanning; Nanoparticles; Nitrophenols - chemistry; Palladium; Palladium - chemistry; Pollution; Reduction; Transformations; Wastes; X-Ray Diffraction; Nitro compound; Material recovery; Bio-Pd; Recovery metals; Nanoparticle; Waste treatment; Mutagen; Sustainable development; Cr(VI); Decontamination; Sequencing batch reactor; Upgrading; Biotransformation; Biological treatment; Teratogen; Platinoid; Organic compounds; Palladium; Aerobic granular biomass; Heavy metal; Waste management; Trace element; Carcinogen; Bioreactor; Waste reuse; Phenols; Poison; Resource management; Microbial granules p-nitrophenol; Nanostructured materials; Chromium VI; Microbial granules; p-nitrophenol
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2014.08.005

Microbial granules cultivated in an aerobic bubble column sequencing batch reactor were used for reduction of Pd(II) and formation of biomass associated Pd(0) nanoparticles (Bio-Pd) for reductive transformation of organic and inorganic contaminants. Addition of Pd(II) to microbial granules incubated under fermentative conditions resulted in rapid formation of Bio-Pd. The reduction of soluble Pd(II) to biomass associated Pd(0) was predominantly mediated by H2 produced through fermentation. X-ray diffraction and scanning electron microscope analysis revealed that the produced Pd nanoparticles were associated with the microbial granules. The catalytic activity of Bio-Pd was determined using p-nitrophenol and Cr(VI) as model compounds. Reductive transformation of p-nitrophenol by Bio-Pd was ∼20 times higher in comparison to microbial granules without Pd. Complete reduction of up to 0.25 mM of Cr(VI) by Bio-Pd was achieved in 24 h. Bio-Pd synthesis using self-immobilized microbial granules is advantageous and obviates the need for nanoparticle encapsulation or use of barrier membranes for retaining Bio-Pd in practical applications. In short, microbial granules offer a dual purpose system for Bio-Pd production and retention, wherein in situ generated H2 serves as electron donor powering biotransformations.