Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Enhancement of polyether biodegradation in activated sludge

Thesis/Dissertation ·
OSTI ID:5081628
Previous studies in this laboratory showed that pretreatment with Petroleum Chemical Extinguisher[reg sign] (PCE), a C[sub 18] unsaturated fatty acid diester of polyethylene glycol (PEG), enhanced the biodegradation of PEG 1,000 and PEG 1,450 in soil. In this study the ability of PCE and other PEG-fatty acid diesters to enhance biodegradation of PEGs in activated sludge was investigated. Additionally, polyether-fatty acid esters similar to PCE were synthesized and tested to determine how they affected biodegradation of PEGs and other polyethers. Attempts were made to understand the mechanism for enhancement of biodegradation. Carbon-dioxide evolution and thin-layer chromatographic analysis indicated degradation of PEG 1,000, PEG 1,450, and PEG 3,350 in sludge samples which were previously exposed to PCE. Those samples which were not pre-treated with PCE showed no detectable PEG degradation during the two-week study. Preexposure to PCE did not enhance subsequent degradation of PEG 8,000, nor polypropylene glycol (PPG) 1,025. However, pretreatment of sludge with a PPG 1,025-di oleic acid ester promoted PPG 1,205 degradation. Interestingly, microbial populations do not seem to be gaining much biomass or energy from the degradation of PEG-di fatty acid esters or PEGs. When PCE-pretreated sludge samples were given [sup 14]C-PEG 3,350 as substrate, evolution of [sup 14]CO[sub 2] occurred and little (<5%) of the [sup 14]C was assimilated by the microorganisms in the sludge. Futhermore, determinations of ATP content and esterase activity of sludge samples suggested that there was not a substantial increase in biomass as a result of degradation of either PCE or PEGs. PCE preexposure effected an increase in PEG dehydrogenase activity. This increase may be due to induction of enzymes responsible for PEG biodegradation or selection for organisms in the microbial population which are PEG degraders.
Research Organization:
Georgia Inst. of Tech., Atlanta, GA (United States)
OSTI ID:
5081628
Country of Publication:
United States
Language:
English