bioremediation

Question 1

what is bioremediation

Answer 1

the use of living organisms to degrade environmental pollutants through waste treatment

Question 2

what is bioremediation used for

Answer 2

contaminated ground water and soil

Question 3

what is the main process of bioremediation?

Answer 3

microbial dégradation and minéralisation of pollutants

Question 4

pollution has been an increasing problem since….?

Answer 4

the second half of 20th century

Question 5

why is there an increase in pollution

Answer 5

with the introduction of novel substances

Question 6

what are the novel substances

Answer 6

pesticides herbicides fungicides
plastics; oil
heavy metals etc

Question 7

what is resistant to biodegradation

Answer 7

recalcitrant compounds

Question 8

why are recalcitrant compounds resistant to biodegradation

Answer 8

unusual substitutions - not recognised by existing enzymes

most common is chlorine aromatic rings

Question 9

what are polychlorinated biphenyls (PCB)

Answer 9

usually oil, viscous liquid

Question 10

what are the properties of polychlorinated biphenyls

Answer 10

high chemical resistance
low electric conductivity
high boiling point
generally inert

Question 11

what can polychlorinated biphenyls be used for

Answer 11

insulator
coolant
fire retardants
paper industry

Question 12

polychlorinated biphenyls were widely used until banned in

Answer 12

1979

Question 13

why were polychlorinated biphenyls banned

Answer 13

cause nausea, eye/nose irritation, headache - also damage immune system and are teratogenic and carcinogenic

Question 14

when does the resistance to biodegradation of recalcitrant compounds begin

Answer 14

at a molecular weight of 500

Question 15

how much oil pollutes the oceans each year

Answer 15

10 X 10^6

Question 16

there is a complex mixture of what in crude oil

Answer 16

aliphatic and aromatic hydrocomounds

Question 17

how does the oil enter the ocean

Answer 17

spillage and disasters

Question 18

what is the best removal method of oil from ocean

Answer 18

skim off surface
addition of detergent (largely cosmetic )
best candidate for treatment : Bioremediation

Question 19

what is the approach of bioremediation

Answer 19

create favourable conditions for development of naturaly occurring biodegraditative organisms

Question 20

what is biostimulation

Answer 20

add specific biodegradative organisms (natural or manufactured)

Question 21

what are the two methods of treatment of bioremediation

Answer 21

treat contaminated area in situ

if possible remove to special treatment site (ex situ)

Question 22

name the two types of ex situ bioremediation

Answer 22

slurry phase and solid phase

Question 23

describe the slurry phase

Answer 23

contaminated soil mixed with water in bioreactor

aerated, nutriece added and mixed

Question 24

describe the solid phase

Answer 24

land farming
biopics
compositing

Question 25

what is composting

Answer 25

degradation by microorganisms at raised temperature

Question 26

what temperature is composting usualy carried out at

Answer 26

55-65

Question 27

describe composting

Answer 27

heat produced by microorganisms

• decrease of bulk density and supply of organic carbon
• spreading into long rows
• rows are regularly turned and mixed
• monitoring of PH, temperature and contaminant concentration

Question 28

what is bioagumentation

Answer 28

methods of producing microorganisms with degradative powers

Question 29

name the two types of bioaugumentation

Answer 29

accelerated evolution

genetic engineering

Question 30

describe accelerated evolution

Answer 30

grow organism in low conc of product.
- and higher conc of similar but degradable product

• gradually increase conc of target compound and reduct conc of similar one
• process selects for spontaneous mutations organisms with much increased ability to utilise target compounds

Question 31

how can mutation rates be increased in accelerated evolution

Answer 31

use of uv radiation or chemical mutagens

e.g - acridine orange

Question 32

what else can you use for acellerted evolution

Answer 32

may also use genome shuffling

Question 33

describe the organisms needed in the polychlorinated biphenyls process

Answer 33

more organisms needed than one
organism 1: remove cl atoms
Organism 2: opens benzene ring
Organism 3: produces acetaldehyde

genetic engineering used to place genes from organism 1-3 onto plasmid single organism capable of metabolising PCB