Lecture 17

Question 1

Bioremediation

Answer 1

Use of microorganims to cleanup oil, toxic chemicals and other environmental pollutants, usually by stimulating the activities of naturally-occuring microbial communities
-Either degradation or transformation of polluant

Question 2

Natural materials

Answer 2

hydrocarbons and metals

Question 3

Xenobiotics

Answer 3

Synthetic chemicals not produced naturally

Question 4

Degradation

Answer 4

Degradation of the polluant (i.e. petroleum or synthetic organic chemicals)

Question 5

Transformation

Answer 5

Transformation of the polluant to a less toxic form (i.e. uranium)

Question 6

Bioremediation of hydrocarbons (e.g. petroleum spills)

Answer 6

• Diverse bacteria, fungi, and some cyanobacteria and green algae can oxidize petroleum products aerobically
• Hydrocarbon-degrading bacteria attach to oil droplets and decomposes the oil and disperse the slick

Question 7

Degradation of stored hydrocarbons

Answer 7

• Storage tankers = potential habitats for hydrocarbon-oxidizing bacteria
• Sufficient sulfate –> sulfate-reducing bacteria can grow and consume hydrocarbons

Question 8

Bioremediation of xenobiotics

Answer 8

• Xenobiotics: Synthetic chemicals that are not naturally occuring:
• Pesticides
• Polychlorinated biphenyls
• Ammunitions
• Chlorinated solvents

Question 9

Cometabolism

Answer 9

Some xenobiotics can be degraded partially or completely if another organic material is present as a primary energy source.

Question 10

Plastics

Answer 10

Most abundant of xenobiotics in the environment

Question 11

Poly-hydroxybutyrate

Answer 11

Carbon storage polymer of bacteria that may serve as an alternative to traditional plastics

Question 12

Wastewater

Answer 12

Domestic sewage or liquid industrial waste that can not be discarded in untreated form into aquatic environments

Question 13

Treatment of wastewater

Answer 13

Employs a combination of physical and chemical methods, as well as industrial-scale use of microorganisms

Question 14

Goals of wastewater treatments facilities:

Answer 14

• Reduce organic and inorganic (N and P) materials in wastewater to a level that no longer supports microbial growth
• To eliminate other potentially toxic materials

Question 15

Biochemical oxygen demand (BOD)

Answer 15

• Amount of dissolved oxygen consumed by microbes to completely oxidize all organic and inorganic matter in water sample
• Efficiency of treatment expressed in terms of a reduction in the BOD

Question 16

Primary treatment

Answer 16

Uses physical separation methods to separate solid and particulate organic and inorganic materials from wastewater

Question 17

Secondary treatment

Answer 17

Uses microbes to decrease the amount of organic matter (BOD) in wastewater through either aerobic or anaerobic means

Question 18

Anaerobic secondary treatment

Answer 18

Involves a series of digestive and fermentative reactions carried out by a consortium of microbes under anoxic conditions
-Process carried out in large enclosed tanks

Question 19

Aerobic secondary treatment

Answer 19

-Uses oxidative reactions carried out by microbes under aerobic conditions to treat wastewater with low levels of organic materials

Question 20

Enhanced biological phosphorous removal (EPBR)

Answer 20

• Example of tertiary treatment

- Uses phosphorus-accumulating organisms to remove P