1 / 11

Bioavailability Constraints in the Uptake of Oil & Hydrocarbons by Microorganisms

Bioavailability Constraints in the Uptake of Oil & Hydrocarbons by Microorganisms . Prof. Suparna Mukherji Centre for Environmental Science & Engineering IIT, Bombay. Definitions and Keywords. 1.

leigh
Télécharger la présentation

Bioavailability Constraints in the Uptake of Oil & Hydrocarbons by Microorganisms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Bioavailability Constraints in the Uptake of Oil & Hydrocarbons by Microorganisms Prof. Suparna Mukherji Centre for Environmental Science & Engineering IIT, Bombay

  2. Definitions and Keywords 1 • NAPLs/Oils : Oil comprises of a series of paraffins, aromatics and asphaltenes which are long chain hydrocarbons, hence is immiscible in water. Oil spills on soil or water are toxic, carcinogenic, and hazardous to the environment. • NAPL: Non-aqueous phase liquids • Being immiscible in aqueous phase their bioavailability to the microorganisms is hindered and hence a major challenge for bioremediation. • Add more slides if required 2 3 4 5

  3. Definitions and Keywords 1 • Bioavailability: availability to microorganisms, it is dependent on mass transfer rates i.e. rate of transfer of pollutants (oils & hydrocarbons) to the aqueous phase. • Bioavailability limitations can be overcome by microbial adherence to oil and direct interfacial uptake of components from the oil phase; and by release of surfactants that cause pseudosolubilization or emulsification of oil. • Surfactants: surface active agents, long chain amphiphillic molecules, can be anionic, cationic, zwitterionic, and non ionic, classified as chemical surfactants and biosurfactants depending upon their origin. • Add more slides if required 2 3 4 5

  4. Definitions and Keywords 1 • Micellization: Micellar solubilisation occurs when the surfactant concentration exceeds CMC (critical micelle concentration), aqueous solubilisation is enhanced by incorporation of hydrophobic molecules into the surfactant micelles. • Sorption: transfer from solution phase onto a solid matrix, includes both • Adsorption: accumulation at the interphase • Absorption: uniform distribution in the solid phase • Add more slides if required 2 3 4 5

  5. INSTRUCTIONS SLIDE Concept details: 1 2 3 4 5

  6. INSTRUCTIONS SLIDE Concept details: 1 2 3 4 5

  7. Concept details 1 2 3 4 5

  8. Concept details 1 2 3 4 5

  9. Questionnaire 1 1. How does the surfactant influence the surface tension? Answers: (a) increases (b) decreases (c) no effect (d)‏ none of these 2. Bioavailability constraint of oils is due to Answers: (a) hydrophobicity (b) immissibility in aqueous phase (c) hydrophilicity (d)‏ both (a) & (b)‏ 3. Micelle formation by surfactants occurs at concentration Answers: (a) does not occur ( b) above CMC (c) below CMC (d) none of these 4. Bioavailability limitations can be avoided by (a) Use of surfactants ( b) direct uptake by microorganisms (c) both a) & b) d) none 2 3 4 5

  10. Links for further reading 1 Singh, A., Van Hamme, J.D., Ward, O.P., 2007. Surfactants in microbiology and biotechnology: Part 2. Application aspects. Biotechnology Advances 25, 99-121. Volkering, F., Breure, A.M., Rulkens, W.H., 1998. Microbiological aspects of surfactant use for biological soil remediation. Biodegradation 8, 401- 417. Surfactant Science Series: a series of books describing the nature , behaiviour, mechanisms, & applications related to surfactants. 2 3 4 5

  11. Thank you

More Related