Abstract
Inorganic matrices were developed for fixed-film bioreactors affording protection to microorganisms and preventing loss of bioreactor productivity during system upsets. These biocarriers, designated Type-Z, contain ion-exchange properties and possess high porosity and a high level of surface area, which provide a suitable medium for microbial colonization. Viable cell populations of 109/g were attainable, and scanning electron micrographs revealed extensive external colonization and moderate internal colonization with aerobic microorganisms. Laboratory-scale bioreactors were established with various biocarriers and colonized with Pseudomonas aeruginosa, and comparative studies were performed. The data indicated that bioreactors containing the Type-Z biocarriers were more proficient at removing phenol (1,000 ppm) than bioreactors established with Flexirings (plastic) and Celite R635 (diatomaceous earth) biocarriers. More significantly, these biocarriers were shown to moderate system upsets that affect operation of full-scale biotreatment processes. For example, subjecting the Type-Z bioreactor to an influent phenol feed at pH 2 for periods of 24 h did not decrease the effluent pH or reactor performance. In contrast, bioreactors containing either Celite or Flexirings demonstrated an effluent pH drop to ∼2.5 and a reduction in reactor performance by 75 to 82%. The Celite reactor recovered after 5 days, whereas the bioreactors containing Flexirings did not recover. Similar advantages were noted during either nutrient or oxygen deprivation experiments as well as alkali and organic system shocks. The available data suggest that Type-Z biocarriers represent an immobilization medium that provides an amenable environment for microbial growth and has the potential for improving the reliability of fixed-film biotreatment processes.
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- Durham D. R., Phibbs P. V., Jr Fractionation and characterization of the phosphoenolpyruvate: fructose 1-phosphotransferase system from Pseudomonas aeruginosa. J Bacteriol. 1982 Feb;149(2):534–541. doi: 10.1128/jb.149.2.534-541.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dwyer D. F., Krumme M. L., Boyd S. A., Tiedje J. M. Kinetics of phenol biodegradation by an immobilized methanogenic consortium. Appl Environ Microbiol. 1986 Aug;52(2):345–351. doi: 10.1128/aem.52.2.345-351.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hallas L. E., Adams W. J., Heitkamp M. A. Glyphosate degradation by immobilized bacteria: field studies with industrial wastewater effluent. Appl Environ Microbiol. 1992 Apr;58(4):1215–1219. doi: 10.1128/aem.58.4.1215-1219.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heitkamp M. A., Adams W. J., Hallas L. E. Glyphosate degradation by immobilized bacteria: laboratory studies showing feasibility for glyphosate removal from waste water. Can J Microbiol. 1992 Sep;38(9):921–928. doi: 10.1139/m92-149. [DOI] [PubMed] [Google Scholar]
- Heitkamp M. A., Camel V., Reuter T. J., Adams W. J. Biodegradation of p-nitrophenol in an aqueous waste stream by immobilized bacteria. Appl Environ Microbiol. 1990 Oct;56(10):2967–2973. doi: 10.1128/aem.56.10.2967-2973.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Klein J., Ziehr H. Immobilization of microbial cells by adsorption. J Biotechnol. 1990 Oct;16(1-2):1–15. doi: 10.1016/0168-1656(90)90061-f. [DOI] [PubMed] [Google Scholar]
- O'Reilly K. T., Crawford R. L. Degradation of pentachlorophenol by polyurethane-immobilized Flavobacterium cells. Appl Environ Microbiol. 1989 Sep;55(9):2113–2118. doi: 10.1128/aem.55.9.2113-2118.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shimp R. J., Pfaender F. K. Effects of surface area and flow rate on marine bacterial growth in activated carbon columns. Appl Environ Microbiol. 1982 Aug;44(2):471–477. doi: 10.1128/aem.44.2.471-477.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]