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 pilot-plant 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 ~0.5 g L(-1), similar to the 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. The final NP products were characterized using XRD, ICP-OES, TEM, FTIR, PL, DLS, HPLC, and C/N analyses, which confirmed that the growth medium without organic buffer enhanced the ZnS NP properties by reducing carbon and nitrogen surface coatings and supporting better dispersivity with similar ACS.
Biosciences Division, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, 37831, USA. moonj@ornl.gov.
Ji-Won
JW
Moon
Biosciences Division, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, 37831, USA.
Tommy J
TJ
Phelps
Fusion Materials for Nuclear Systems Division, ORNL, Oak Ridge, TN, 37831, USA.
Curtis L
CL
Fitzgerald
Energy and Transportation Science Division, ORNL, Oak Ridge, TN, 37831, USA.
Randall F
RF
Lind
Biosciences Division, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, 37831, USA.
James G
JG
Elkins
Energy and Transportation Science Division, ORNL, Oak Ridge, TN, 37831, USA.
Gyoung Gug
GG
Jang
Materials Science and Technology Division, ORNL, Oak Ridge, TN, 37831, USA.
Pooran C
PC
Joshi
Chemical Sciences Division, ORNL, Oak Ridge, TN, 37831, USA.
Michelle
M
Kidder
Materials Science and Technology Division, ORNL, Oak Ridge, TN, 37831, USA.
Beth L
BL
Armstrong
Materials Science and Technology Division, ORNL, Oak Ridge, TN, 37831, USA.
Thomas R
TR
Watkins
Center for Nanophase Materials Sciences, ORNL, Oak Ridge, TN, 37831, USA.
Ilia N
IN
Ivanov
Biosciences Division, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN, 37831, USA.
David E
DE
Graham
D000693:Anaerobiosis; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000378:metabolism*; D013440:Sulfides / Q000378:metabolism*; D046968:Thermoanaerobacter / Q000378:metabolism*; D017967:Zinc Compounds / Q000378:metabolism*
D013440:Sulfides; D017967:Zinc Compounds; C031238:zinc sulfide
Microbially mediated manufacturing; Pilot plant reactor; Scalability; Zinc sulfide nanoparticles