Performance Characterization of a Laboratory-Scale Bioreactor with Liquid Suspensions ofAlcaligenes EutrophusJMP134

Abstract

Trichloroethylene (TCE) was degraded in a single-stage, continuously stirred tank reactor (CSTR) bioreactor containing pure cultures of liquid-dispersed Alcaligenes eutrophus JMP134. Phenol was supplied as the sole source of carbon and energy for induction of catabolic activities. Operating conditions were varied in a series of randomly ordered experiments. The independent variables were influent TCE concentration, influent phenol concentration, and hydraulic residence time. The dependent variable was the percent on influent TCE degraded or degradation efficiency. The highest degradation efficiency observed was 98.6%. An empirical equation was fitted to the data in the form of degradation efficiency as a function of the three independent variables. A close match was achieved between the equation and the data. This equation is valid only where the phenol was oxidized below the level of detection in the effluent (150 {mu}g/L). This equation is useful for bioreactor design and operation. Hydraulic residence time was noted to have a relatively small effect on degradation efficiency. Phenol and TCE were competitive, as expected in a cometabolism system. The implication for bioreactor operation is that phenol levels must be closely matched to TCE levels for optimum performance. 30 refs., 5 figs., 2 tabs.