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Nanobiocatalytic Degradation of Acid Orange 7
Date
2010Type
ThesisDepartment
Chemical and Materials Engineering
Degree Level
Master's Degree
Abstract
The catalytic properties of various metal nanoparticles have led to their use in
environmental remediation applications. However, these remediation strategies are limited
by their ability to deliver catalytic nanoparticles and a suitable electron donor to large
treatment zones. Clostridium pasteurianum BC1 cells, loaded with bio‐Pd nanoparticles,
were used to effectively catalyze the reductive degradation and removal of Acid Orange 7
(AO7), a model azo compound. Hydrogen produced fermentatively by the C. pasteurianum
BC1 acted as the electron donor for the process. Pd‐free bacterial cultures or control
experiments conducted with heat‐killed cells showed limited reduction of AO7.
Experiments also showed that the in situ biological production of H2 by C. pasteurianum BC1
was essential for the degradation of AO7, which suggests a novel process where the in situ
microbial production of hydrogen is directly coupled to the catalytic bio‐Pd mediated
reduction of AO7. The differences in initial degradation rate for experiments conducted
using catalyst concentrations of 1ppm Pd and 5ppm Pd and an azo dye concentration of
100ppm AO7 was 0.39hr‐1 and 1.94hr‐1 respectively, demonstrating the importance of
higher concentrations of active Pd(0). The degradation of AO7 was quick as demonstrated
by complete reductive degradation of 50ppm AO7 in 2 hours in experiments conducted
using a catalyst concentration of 5ppm Pd. Dye degradation products were analyzed via Gas
Chromatograph‐Mass Spectrometer (GCMS), High Performance Liquid Chromatography
(HPLC), UltraViolet‐Visible spectrophotometer (UV‐Vis) and Matrix‐Assisted Laser
Desorption/Ionization (MALDI) spectrometry. The presence of 1‐amino 2‐naphthol, one of
the hypothesized degradation products, was confirmed using mass spectrometry.
Permanent link
http://hdl.handle.net/11714/4474Additional Information
Committee Member | Childress, Amy; Misra, Manoranjan |
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Rights | In Copyright(All Rights Reserved) |
Rights Holder | Author(s) |