Experimental Study of Biodegradation of Ethanol and Toluene Vapors

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Ethanol/biomass concentration, g/L 7 6 5 4 3 2 1 0 S(6g/L) S(4g/L) S(2g/L) X(6g/L) X(4g/L) X(2g/L) 0 10 20 30 Time, h Figure 5-11(a). Theoretical prediction of batch growth on ethanol (2, 4, 6 g/L) Figures 5-11 (b)-(c) demonstrate the concentration predictions for biomass (X), ethanol (S), ammonia ((NH 4 ) 2 SO 4 , C n ), along with oxygen consumption (Q o ), carbon dioxide formation (Qc) and ATP consumption (r ATP ) during a batch growth with ethanol at initial concentrations of 4 and 6 g/L, respectively. The calculations are described below: (1) Biomass and ethanol mass concentrations are calculated from the mole concentrations obtained by Equations (5-34) and (5-35) as mentioned above. (2) Ammonia concentration is calculated by: C n = C − 0.2r * (132 / 2) (g/L) (5-57) n0 x where C n0 is the initial (NH 4 ) 2 SO 4 concentration used in the medium, is 2.0 g/L. (3) The amount of ATP consumed for the formation of biomass including maintenance term can be described by (Roels, 1980): 122
ATP 1 = Y max ATP r x + m ATP ⋅ C x (5-58) where r ATP is the ATP consumption rate (mol/L-h); the parameter Y ATP is the reciprocal of parameter K in Equation (5-4), which has been determined in Section 5.3.1. (4) The following equations (Equations (5-59a) and 5-59b) are applied in the prediction of oxygen uptake rates and mass transfer rates. Oxygen consumption rate is calculated as: Q = μC Y *32 (g/L-h) (5-59a) O / 2 x O2 Oxygen mass transfer rate is described by: Q o 2 _ mass * = k a ⋅ ( C − C ) (5-59b) L o 2 o 2 Figures (5-11b) and (5-11c) indicate that oxygen consumption reaches higher rates when the log phase starts. A peak in the product of μ C x , and thus the total oxygen demand, occurs near the end of the exponential phase and the approach to the stationary phase. The results also indicate that a higher initial concentration of ethanol results in a higher biomass level, and thus a higher oxygen demand for cell growth. For instance, the maximum oxygen demand of 1.6 g/L-h for 6 g/L initial concentration is higher than that of 0.9 g/L-h for initial concentration of 4 g/L. In the cases of an ethanol initial concentrations below 6 g/L, the maximum oxygen supply ( k a ⋅ than the maximum oxygen demand ( μ max C x / Y O 2 * L C o2 ) is always higher ). Thus the main resistance to increased oxygen consumption is microbial metabolism and the reaction appears to be always growth rate limited, not oxygen mass transfer limited. This agrees with the 123
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BIOREMEDIATION OF VOLATILE ORGANIC
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ABSTRACT The mass transfer of ethan
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effect on the growth of P. putida.
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ACKNOWLEDGMENT Of the countless peo
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TABLE OF CONTENTS PERMISSION TO USE
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4.3 Batch Growth on Ethanol and Ben
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LIST OF FIGURES Figure 3-1. Schemat
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Figure 5.3 (b) Simulation of ethano
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Figure 5-16. Continuous removal of
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NOMENCLATURE a - Interfacial area,
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CHAPTER ONE - INTRODUCTION 1.1 Air
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esults (van Groenestijn and Hesseli
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experimental results are presented
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Table 2.2 VOC Emissions in the U.S.
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(paint shop effluents, for instance
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combustion provides 70 to 90% air p
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used to degrade ethanol vapours and
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g m -3 . This would suggest that th
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treatment, This excessive biomass f
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The simultaneous degradation of tol
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emoves only water-soluble gases. Wa
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2.2.6 Pseudomonas It is well known
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2.3.2 Growth Models with Inhibition
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where µ is the total specific grow
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2.4.1 Batch Reactor In a batch reac
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discharged from the other end. The
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element solution consisted of (gram
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growth on ethanol, 20-48 hours for
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Gas phase samples of toluene were c
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Inlet sampler Exit sampler To fume
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Once the oxygen meter indicated a s
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centrifuged and the supernatant was
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where k L a is the volumetric mass
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Figure 4-2a shows ethanol liquid co
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coefficient (k L a) in the well-mix
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calculated by dividing the gas volu
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Average bubble diameter, mm 8 7 6 5
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Bioflow III bioreactor. Equation (4
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3.5 y=Ln(S0/S) 3 2.5 2 1.5 1 y = 12
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Ethanol and biomass concentration,
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4.3.2 Batch Growth on Benzyl Alcoho
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Biomass and benzyl alcohol concentr
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ethanol loading was beyond the maxi
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Table 4-2. Comparison of bioremedia
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Biomass, benzyl alcohol and toluene
Page 91 and 92: 4.4.3 Toluene-ethanol Bioremediatio
Page 93 and 94: Substrate and biomass concentration
Page 95 and 96: Biomass and benzyl alcohol concentr
Page 97 and 98: Biomass and benzoic acid concentrat
Page 99 and 100: ethanol. These results clearly indi
Page 101 and 102: CHAPTER FIVE - MATHEMATICAL MODELIN
Page 103 and 104: The stoichiometry of the biomass sy
Page 105 and 106: synthesis and in the ethanol catabo
Page 107 and 108: 1 max Y ex = − 0.635 + 2δ + K 3
Page 109 and 110: Biomass Eq.5-18 Benzyl Alcohol Eq.5
Page 111 and 112: r x r N -1.27 -1 0 1 0 0 -0.2 0 0 2
Page 113 and 114: φ = −θ b ⋅ν (5-31) φ b = 1.
Page 115 and 116: The data sets used to evaluate the
Page 117 and 118: Figures 5.4a and 5.4b present 95% c
Page 119 and 120: Ethanol and biomass concentration (
Page 121 and 122: Ethanol measured (C-mol/L) 0.3 0.25
Page 123 and 124: Figures 5.5 (a-d) demonstrate the s
Page 125 and 126: Benzyl alcohol and biomass concentr
Page 127 and 128: Benzyl alcohol measured (C-mol/L) 0
Page 129 and 130: x = 5 ∑ i= 1 x N i (5-40) where x
Page 131 and 132: ethanol in a steady state mode is l
Page 133 and 134: where ν 1 , ν 2 , ν 3, ν 4 are
Page 135 and 136: Biomass concentration, g/L 1.5 1 0.
Page 137 and 138: φ T =ν 4 (5-53b) φx = −ν 1 (5
Page 139 and 140: In this study, a metabolic model ha
Page 141: Equations (5-34) and (5-35) and the
Page 145 and 146: Ethanol, biomass and ammonium conce
Page 147 and 148: Figure 5-13a shows that the lower t
Page 149 and 150: Biomass, substrate concentrations,
Page 151 and 152: C e DKe = (5-63) μ − D m Equatio
Page 153 and 154: corresponds with the value associat
Page 155 and 156: Biomass and ethanol concentrations
Page 157 and 158: than 4.0 mg/L at all dilution rates
Page 159 and 160: Biomass, benzyl alcohol and ammonia
Page 161 and 162: negligible ( y out , e = 0) , and e
Page 163 and 164: Figure 5-17 shows the results at a
Page 165 and 166: Biomass Concentrations, g/L 3.5 3 2
Page 167 and 168: C x ( 1 max Q max = ⋅{ D( Cb0 −
Page 169 and 170: 1.2 g/L, the system could not be op
Page 171 and 172: The continuous models can capture a
Page 173 and 174: • Air stripping coefficients obta
Page 175 and 176: Toluene acts as an inhibitor on the
Page 177 and 178: Bruining, W. J., G. E. H. Joosten,
Page 179 and 180: Falatko, D. M., and J. T. Novak, 19
Page 181 and 182: Keuning, S., and D. Jager, 1994.
Page 183 and 184: Orshansky, F., and N. Narkis, 1997.
Page 185 and 186: Togna, A. P, M. Singh, 1994. “Bio
Page 187 and 188: APPENDIX A. Important Metabolic Pat
Page 189 and 190: III. Toluene Pathway (Adapted from
Page 191 and 192: Appendix B. Calibration Procedure a
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Figure B-2. Pseudomonas putida (ATC
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Appendix B-3. Calibration of Chemic
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Appendix B-4. Calibration of Toluen
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Appendix C. Experimental Results: A
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Probe response time, s 12 10 8 6 4
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Appendix C-2. Fed-batch Operation B
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Appendix D: Mathematical Solutions
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The microscopic model allows the fo
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13δ Y o , = 0.585 2 x = (D-24) (8K
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2 σ = −1.3E − 06 (E-11) Y xe Y
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Biomass, ethanol, and acetic acid c
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Experimental Study of Biodegradation of Ethanol and Toluene Vapors

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