Document Type


Date of Award

Fall 1-31-1995

Degree Name

Master of Science in Engineering Science- (M.S.)


Chemical Engineering, Chemistry and Environmental Science

First Advisor

Samir S. Sofer

Second Advisor

Richard B. Trattner

Third Advisor

Barbara B. Kebbekus


The primary purpose of this work is to help define the optimum window of operations for an immobilized cell oxidative bioreactor. The analytical technique employed requires no outside verification (such as G.C. analysis) and is independent of liquid flow rate. Method of aeration has been determined to be an important parameter for optimizing bioreactor efficiency, and optimization of the quantity of hydrogen peroxide added to provide oxygen during bio-oxidation has been investigated. Ammonium hydroxide as a fixed nitrogen source can be used to restore the vitality of the bioreactor under certain conditions.

The effects of several different methods of providing oxygen on bio-oxidation were analyzed. These methods included aeration at the center of the reservoir (18" from the pump inlet leading to the biosupport), aeration near the pump inlet (3" away), and providing oxygen by means of injection of hydrogen peroxide into the reservoir. Generally, aeration nearer to the cylinder led to faster initial rates of biodegradation of the phenol. With hydrogen peroxide, an injection of 0.5 ml of 30% H2O2 (3.8 ppm H2O2) best facilitated the bio-oxidation of 0.5 g phenol, whereas higher amounts caused inhibition.

The use of ammonium hydroxide to speed up slow reaction rates has been demonstrated, with the minimum effective injection determined to be approximately 10 ml concentrated NH4OH (21 ppm). Quantitation using the dissolved oxygen reaction patterns has been briefly discussed. The effect of both dilution and of changing liquid flow rate on baseline dissolved oxygen levels has been analyzed. Also, a guide has been prepared for the recognition of some abnormal dissolved oxygen level patterns for troubleshooting and assessing systemic causes and solutions and general bioreactor operation observations and suggestions have been provided.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.