Kinetics of phenol biodegradation /
| Main Author: | |
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| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1991.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | The objective of this work was to investigate phenol bio degradation in batch and continuous cultures. The conventional activated sludge process is a viable technique in removing phenolic wastes from industrial waste effluents. The intrinsic kinetic data required for design of these industrial biotreatment processes have generally been obtained in a series of batch or continuous culture studies. But until now, due to incomplete characterization of batch and continuous cultures, it has been a major dilemma among the environmental scientists whether the batch or the continuous culture studies yield the most accurate kinetic data. Therefore, we have investigated phenol biodegradation in batch reactors and continuously stirred tank reactors (CSTRs). Activated sludge bacteria, acclimated to phenol, were used in the experiments. In batch cultures, the effects of starving the bacteria prior to conducting a batch experiment, varying So/Xo ratio and consecutive pulse feeding of phenol on microbial kinetics were investigated. Starvation of the bacteria resulted in a lag phase. As the So/Xo was increased, there was an increase in the observed values of the half saturation constant; to explain this, a decrease in the induced enzymes was correlated with an increase in the So/Xo due to toxicity of phenol. A new parameter called the induction factor was introduced into the microbial growth equation (Monod or Haldane, whichever is applicable). The inhibition constant decreased as phenol was pulsed into the reactor in consecutive batch experiments at the same So/Xo ratio; to describe this trend, an increase in the concentration of the inactive biomass substrate complex was postulated and a new parameter called the intensity factor was incorporated into the Haldane equation. With the addition of two new parameters to the Haldane equation, a new design equation that is not mechanistic was proposed to account for the effects of So/Xo ratio and consecutive pulse feeding of phenol on microbial kinetics. The model proved to be very useful and applicable for modelling microbial growth on toxic substrates since it would be possible to define with the development of this model, the conditions under which valid batch data can be obtained to set up a database for the kinetic parameter values for different toxic organics... |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Chemical Engineering." |
| Physical Description: | xii, 214 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |