DSpace Repository

Multicapillary membrane bioreactor design

Show simple item record

dc.creator Ntwampe, Seteno KO
dc.date 2013-02-20T08:24:45Z
dc.date 2013-02-20T08:24:45Z
dc.date 2005
dc.date.accessioned 2017-05-10T10:22:00Z
dc.date.available 2017-05-10T10:22:00Z
dc.identifier http://hdl.handle.net/11189/761
dc.identifier.uri http://hdl.handle.net/11189/761
dc.description Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2005
dc.description The white rot fungus, Phanerochaete chrysosporium, produces enzymes, which are capable of degrading chemical pollutants. It was detennined that this fungus has multiple growth phases. The study provided infonnation that can be used to classify growth kinetic parameters, substrate mass transfer and liquid medium momentum transfer effects in continuous secondary metabolite production studies. P. chrysosporium strain BKMF 1767 (ATCC 24725) was grown at 37 QC in single fibre capillary membrane bioreactors (SFCMBR) made of glass. The SFCMBR systems with working volumes of 20.4 ml and active membrane length of 160 mm were positioned vertically. Dry biofilm density was determined by using a helium pycnometer. Biofilm differentiation was detennined by taking samples for image analysis, using a Scanning Electron Microscope at various phases of the biofilm growth. Substrate consumption was detennined by using relevant test kits to quantify the amount, which was consumed at different times, using a varying amount of spore concentrations. Growth kinetic constants were detennined by using the substrate consumption and the dry biofilm density model. Oxygen mass transfer parameters were determined by using the Clark type oxygen microsensors. Pressure transducers were used to measure the pressure, which was needed to model the liquid medium momentum transfer in the lumen of the polysulphone membranes. An attempt was made to measure the glucose mass transfer across the biofilm, which was made by using a hydrogen peroxide microsensor, but without success. Dry biofilm density was modelled by using a growth rate constant of 0.035 hr-I which was classified as being equivalent to the specific growth rate. Glucose consumption increased with the different biofilm growth phases, with an average of 94.7 glm3.hr consumed over a period of 264 hrs. After 48 hrs, 90% of the ammonia fed to the SFCMBR systems, was consumed compared to 15% ofthe glucose. An average glucose-based growth yield, coefficient ofapproximately 0.202 g biofilm/g glucose, was detennined compared to 14.3 g biofilm/g ammonia of ammonia tartrate. The consumption of substrates increased when a higher concentration of spores were immobilised in the bioreactors. The biofilm structure, during the exponential phase, showed a vegetative state near the substratum, which supported the aerial mycelia. During the structural steady state, the compact aerial mycelia produced reproductive propagules, thus reducing oxygen flux during this stage. In younger mycelia, oxygen consumption was generally lower, with higher consumption rates of greater than 800 glm3.hr occurring during the exponential phase ofthe primary growth phase. Pressure transducers were used to measure pressure at the inlet and outlet of the substratum in a bioreactor without any immobilised biofilm. Mathematical models that were modified to suit the operating conditions were used to predict the outlet pressure using the inlet pressure. Mass transfer coefficient values were determined in the range of 0.131 to 0.602 m/hr with an average oxygen penetration depth of 390Jlm. Oxygen based Monod's saturation constant in the range of 0.567 to 2.07 glm3 with average biofilm diffusion coefficients of I.03E-05 to 1.27E-5 m21hr, were also obtained. Manganese Peroxidase (MnP) and Lignin Peroxidase (LiP) are two of the extracellular enzymes produced by Phanerochaete chrysosporium biofilms. These enzymes, have demonstrated to be major components of the lignin degradation system. They are able to metabolise a variety of orgarnc chemicals, many of which are pollutants in liquid effluents. The commissioning of vertical MCMBR systems was done by monitoring the substrate consumption, enzyme production and oxygen distribution within the biofilm, which was formed. In a period of 0 to 5 days, more LiP (above 5 U/L) was produced compared to MnP. During this operational period, MnP production was lower than 5 U/L. The conditions under which the MCMBR systems were operated favoured higher LiP production. Permeate collected from one of the MCMBR systems were used to evaluate the phenol degradation, in which 66.7% of phenol content was reduced in olive wastewaters.
dc.language en
dc.rights http://creativecommons.org/licenses/by-nc-sa/3.0/za/
dc.subject Bioreactors -- Design and construction
dc.subject Organic compounds -- Biodegradation
dc.subject Immobilized enzymes
dc.subject Water -- Purification
dc.subject Membrane reactors
dc.title Multicapillary membrane bioreactor design
dc.type Thesis

Files in this item

Files Size Format View
Multicapillary membrane bioreactor design.pdf 15.28Mb application/pdf View/Open

This item appears in the following Collection(s)

Show simple item record