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Title: Manufacturing demonstration of microbially mediated zinc sulfide nanoparticles in pilot-plant scale reactors

The thermophilic anaerobic metal-reducing bacterium Thermoanaerobacter sp. X513 efficiently produces zinc sulfide (ZnS) nanoparticles (NPs) in laboratory-scale ( ≤24-L) reactors. To determine whether this process can be up-scaled and adapted for pilot-plant production while maintaining NP yield and quality, a series of meso-scale experiments were performed using 100-l and 900-l reactors. Pasteurization and N2-sparging replaced autoclaving and boiling for deoxygenating media in the transition from small-scale to pilot-plant reactors. Consecutive 100-L batches using new or recycled media produced ZnS NPs with highly reproducible ~2 nm average crystallite size (ACS) and yields of ~0.5g L-1, similar to small-scale batches. The 900-L pilot plant reactor produced ~ 320 g ZnS without process optimization or replacement of used medium; this quantity would be sufficient to form a ZnS thin film with ~120 nm thickness over 0.5 m width 13 km length. At all scales, the bacteria produced significant amounts of acetic, lactic and formic acids, which could be neutralized by the controlled addition of sodium hydroxide without the use of an organic pH buffer, eliminating 98% of the buffer chemical costs. In conclusion, the final NP products were characterized using XRD, ICP-OES, FTIR, DLS, and C/N analyses, which confirmed the growth medium withoutmore » organic buffer enhanced the ZnS NP properties by reducing carbon and nitrogen surface coatings and supporting better dispersivity with similar ACS.« less
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [1] ;  [3] ;  [4] ;  [5] ;  [4] ;  [4] ;  [6] ;  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Fusion Materials for Nuclear Systems Division
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Energy and Transportation Science Division
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
  5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division
  6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Science (CNMS)
Publication Date:
OSTI Identifier:
1311219
Grant/Contract Number:
AC05-00OR22725; CPS 24762
Type:
Accepted Manuscript
Journal Name:
Applied Microbiology and Biotechnology
Additional Journal Information:
Journal Volume: 100; Journal Issue: 18; Journal ID: ISSN 0175-7598
Publisher:
Springer
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). High Temperature Materials Laboratory (HTML)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY Pilot plant reactor; Microbially mediated manufacturing; Zinc sulfide; nanoparticles; Scalability