The biodegradation of olive oil and the treatment of lipid-rich wool scouring wastewater under aerobic thermophilic conditions

Citation
P. Becker et al., The biodegradation of olive oil and the treatment of lipid-rich wool scouring wastewater under aerobic thermophilic conditions, WATER RES, 33(3), 1999, pp. 653-660
Citations number
21
Categorie Soggetti
Environment/Ecology
Journal title
WATER RESEARCH
ISSN journal
00431354 → ACNP
Volume
33
Issue
3
Year of publication
1999
Pages
653 - 660
Database
ISI
SICI code
0043-1354(199902)33:3<653:TBOOOA>2.0.ZU;2-2
Abstract
The biodegradation of olive oil and the treatment of the lipid-rich wool sc ouring wastewater were studied under aerobic thermophilic (65 degrees C) co nditions using the newly isolated strain Bacillus thermoleovorans IHI-91. I n a continuously operated laboratory-scale stirred-tank reactor olive oil w as degraded to more than 90% at a residence time of 2 h with a maximum volu metric degradation rate of 900 mg l(-1) h(-1). A relatively high maximum bi omass yield of 1.05 g dry cell weight per g olive oil consumed was measured and a maintenance coefficient of 0.04 g olive oil(g DCW)(-1) h(-1) was cal culated from steady-state data. A severe growth inhibition was observed whe n the feed olive oil concentration was increased to more than 4 g l(-1). Li pid removal from the highly loaded wool scouring wastewater (COD of 77000 m g l(-1)) was 20-30% at a residence time of 10-20 h while the COD removal wa s 15-20%. GC-MS analysis revealed that longchain fatty acids up to C18 were efficiently degraded while degradation of the predominant sterol-fraction of the wool grease was not detected. The high concentrations of volatile fa tty acids (60 mM acetic acid, 13 mM propionic acid) present in the wastewat er were completely removed even at residence times of 2 h. Compared with da ta from mesophilic processes the lipid degradation rates obtained under the rmophilic conditions are extremely high. (C) 1998 Elsevier Science Ltd. All rights reserved.