Removal of phenanthrene by rhodococcus zopfii in an attached natural biofilm / Rosadibah Mohd Towel

Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds, which present as contaminants in wastewater treatment plants. The bacterial mitigation technique was employed in this study, which was Rhodococcus species to degrade one of the potential PAHs, phenanthrene. Fourier transform i...

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Main Author: Mohd Towel, Rosadibah
Format: Thesis
Language:English
Published: 2021
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Online Access:https://ir.uitm.edu.my/id/eprint/46900/1/46900.pdf
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spelling my-uitm-ir.469002022-03-07T06:19:13Z Removal of phenanthrene by rhodococcus zopfii in an attached natural biofilm / Rosadibah Mohd Towel 2021 Mohd Towel, Rosadibah Microbial ecology Water. Aquatic microbiology Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds, which present as contaminants in wastewater treatment plants. The bacterial mitigation technique was employed in this study, which was Rhodococcus species to degrade one of the potential PAHs, phenanthrene. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were implemented for the identification of functional groups and the absorption characteristic on the natural biofilm surface. The polymerase chain reaction (PCR) method has successfully identified and verified the bacteria as Rhodococcus zopfii DSM 44. In this study, a complete biodegradation of 1mg/L phenanthrene by R. zopfii was achieved within 7 days, indicating the attachment of R. zopfii on the natural biofilm surface. The biodegradation rate of phenanthrene in the presence of natural biofilm was 0.26mg/L/day (R2=0.95), which was 1.52 times higher than that without natural biofilm (0.17mg/L/day) (R2=0.95). Approximately, 46%, 99%, and 100% biodegradation of phenanthrene by R. zopfii significantly occurred in the wastewater at initial bacteria populations of 106, 108, and 1010, respectively. The biodegradation rate of phenanthrene was accelerated by 54% in the presence of natural biofilm and high initial bacteria population (1010) to 0.33mg/L/day (R2=0.93), which was 1.08 times higher than the biodegradation rate at 108 bacteria population (0.30mg/L/day) (R2=0.94). Meanwhile, the optimum pH condition required to enhance the biodegradation of phenanthrene by R. zopfii was at neutral pH (pH 7.0-7.2), with 0.44mg/L/day (R2=0.86) biodegradation rate was achieved at an initial pH of 7, which was 1.30 times higher than that at initial pH 7.2 (0.34mg/L/day) (R2=0.98). In this study, coumarin, catechol, and phthalic acids were identified in the phenanthrene degradation, and detailed phenanthrene pathway was constructed based on the metabolic results. The two (2) mathematical equations were successfully formulated to simulate the whole system of biodegradation of phenanthrene by R. zopfii with natural biofilm, namely, non-inhibition (below 50mg/L) and inhibition (above 50mg/L) equations. This study ultimately contributes to the remediation efficiency of municipal wastewater containing phenanthrene. Moreover, this study verified the non-toxic intermediate compound on the by-products study of degradation of phenanthrene 2021 Thesis https://ir.uitm.edu.my/id/eprint/46900/ https://ir.uitm.edu.my/id/eprint/46900/1/46900.pdf text en public phd doctoral Universiti Teknologi MARA Faculty of Civil Engineering Amir, Amnorzahira (Ir. Dr.)
institution Universiti Teknologi MARA
collection UiTM Institutional Repository
language English
advisor Amir, Amnorzahira (Ir. Dr.)
topic Microbial ecology
Microbial ecology
spellingShingle Microbial ecology
Microbial ecology
Mohd Towel, Rosadibah
Removal of phenanthrene by rhodococcus zopfii in an attached natural biofilm / Rosadibah Mohd Towel
description Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds, which present as contaminants in wastewater treatment plants. The bacterial mitigation technique was employed in this study, which was Rhodococcus species to degrade one of the potential PAHs, phenanthrene. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were implemented for the identification of functional groups and the absorption characteristic on the natural biofilm surface. The polymerase chain reaction (PCR) method has successfully identified and verified the bacteria as Rhodococcus zopfii DSM 44. In this study, a complete biodegradation of 1mg/L phenanthrene by R. zopfii was achieved within 7 days, indicating the attachment of R. zopfii on the natural biofilm surface. The biodegradation rate of phenanthrene in the presence of natural biofilm was 0.26mg/L/day (R2=0.95), which was 1.52 times higher than that without natural biofilm (0.17mg/L/day) (R2=0.95). Approximately, 46%, 99%, and 100% biodegradation of phenanthrene by R. zopfii significantly occurred in the wastewater at initial bacteria populations of 106, 108, and 1010, respectively. The biodegradation rate of phenanthrene was accelerated by 54% in the presence of natural biofilm and high initial bacteria population (1010) to 0.33mg/L/day (R2=0.93), which was 1.08 times higher than the biodegradation rate at 108 bacteria population (0.30mg/L/day) (R2=0.94). Meanwhile, the optimum pH condition required to enhance the biodegradation of phenanthrene by R. zopfii was at neutral pH (pH 7.0-7.2), with 0.44mg/L/day (R2=0.86) biodegradation rate was achieved at an initial pH of 7, which was 1.30 times higher than that at initial pH 7.2 (0.34mg/L/day) (R2=0.98). In this study, coumarin, catechol, and phthalic acids were identified in the phenanthrene degradation, and detailed phenanthrene pathway was constructed based on the metabolic results. The two (2) mathematical equations were successfully formulated to simulate the whole system of biodegradation of phenanthrene by R. zopfii with natural biofilm, namely, non-inhibition (below 50mg/L) and inhibition (above 50mg/L) equations. This study ultimately contributes to the remediation efficiency of municipal wastewater containing phenanthrene. Moreover, this study verified the non-toxic intermediate compound on the by-products study of degradation of phenanthrene
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Mohd Towel, Rosadibah
author_facet Mohd Towel, Rosadibah
author_sort Mohd Towel, Rosadibah
title Removal of phenanthrene by rhodococcus zopfii in an attached natural biofilm / Rosadibah Mohd Towel
title_short Removal of phenanthrene by rhodococcus zopfii in an attached natural biofilm / Rosadibah Mohd Towel
title_full Removal of phenanthrene by rhodococcus zopfii in an attached natural biofilm / Rosadibah Mohd Towel
title_fullStr Removal of phenanthrene by rhodococcus zopfii in an attached natural biofilm / Rosadibah Mohd Towel
title_full_unstemmed Removal of phenanthrene by rhodococcus zopfii in an attached natural biofilm / Rosadibah Mohd Towel
title_sort removal of phenanthrene by rhodococcus zopfii in an attached natural biofilm / rosadibah mohd towel
granting_institution Universiti Teknologi MARA
granting_department Faculty of Civil Engineering
publishDate 2021
url https://ir.uitm.edu.my/id/eprint/46900/1/46900.pdf
_version_ 1783734772824014848