COMPARISON OF RELATIVE RATES OF BTEX BIODEGRADATION USING RESPIROMETRY

Citation
Ct. Goudar et Ka. Strevett, COMPARISON OF RELATIVE RATES OF BTEX BIODEGRADATION USING RESPIROMETRY, Journal of industrial microbiology & biotechnology, 21(1-2), 1998, pp. 11-18
Citations number
33
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biothechnology & Applied Migrobiology
Volume
21
Issue
1-2
Year of publication
1998
Pages
11 - 18
Database
ISI
SICI code
Abstract
Biodegradation of BTEX by a microbial consortium isolated from a close d municipal landfill was studied using respirometric techniques. The k inetics of biodegradation were estimated from experimental oxygen upta ke data using a nonlinear parameter estimation technique, All of the s ix compounds were rapidly degraded by the microbial culture and no sub strate inhibition was observed at the concentration levels examined (2 00 mg L-1 as COD). Microbial growth and contaminant degradation were a dequately described by the Monod equation. Considerable differences we re observed in the rates of BTEX biodegradation as seen from the estim ates of the kinetic parameters, A three-fold variation was seen in the values of the maximum specific growth rate, mu(max). The highest valu e of mu(max) was 0.389 h(-1) for p-xylene while o-xylene was character ized by a mu(max) value of 0.14 h(-1), the lowest observed in this stu dy. The half saturation coefficient, K-s, and the yield coefficient, Y , varied between 1.288-4.681 mg L-1 and 0.272-0.645 mg mg(-1), respect ively. Benzene and o-xylene exhibited higher resistance to biodegradat ion while toluene and p-xylene were rapidly degraded. Ethylbenzene and m-xylene were degraded at intermediate rates, In biodegradation exper iments with a multiple substrate matrix, substrate depletion was slowe r than in single substrate experiments, suggesting an inhibitory natur e of substrate interaction.