Ecotoxicology And Wastewater Treatment

Question 1

Human Activities that affect ecosystems by…

Answer 1

1)Polluting them with substances that do not occur there naturally
2)by significantly increasing concentrations of substances already present

Question 2

Contaminant

Answer 2

An agent that causes changes in the physical chemical or biological properties of an environment or an organism

Question 3

4 main contaminants

Answer 3

-Inorganic
-Organic
-Microbial
-Radioactive

Question 4

Toxicity

Answer 4

When a contaminant effectively harms an organism it is toxic:
1) Concentration
2)Type of organism it comes in contact with
3)Length of exposure

Question 5

Toxicity Threshold

Answer 5

The minimum concentration of a substance that produces a significant harmful effect in an organism

Question 6

Lethal Doses

Answer 6

LD50 is the the does that causes death among 50% of individuals

Question 7

Bioaccumulation

Answer 7

The process by which a contaminant from the environment or the food supply accumulates in an organism

Question 8

Bioconcentration

Answer 8

A special case of brioaccumulation by which an organism accumulates a contaminant through direct contact with its environment from sources other than food (specifically a water environment )

Question 9

Biotechnology

Answer 9

Living organisms can be used to either LIMIT discharge or to BREAK IT DOWN

Question 10

Biodegration

Answer 10

The breakdown of organic matter into inorganic matter by microorganisms

Question 11

Bioremediation

Answer 11

A biotechnology for cleaning up a polluted site using microorganisms that DECOMPOSE contaminants

Question 12

Phytoremediation

Answer 12

Biotechnology that uses plants or algae to eliminate/absorb(not break down) contaminants from a site

Question 13

Wastewater

Answer 13

Water that is discharged after household or industrial use and that is polluted as a result of human activities

Question 14

Waste water contaminants

Answer 14

• sand and suspended particles
• pathogens (microorganisms that cause disease)
• decomposing organic waste (dead organisms or feces)
• nutrients that simulate excessive growth of algae, Cyanobacteria and aquatic plants chemicals

Question 15

Septic Tank

Answer 15

• solid waste settles at the bottom = sludg
• collect the sludge and treat it
• liquid part drains out of the tank into surrounding land
• can use microorganisms to treat the liquids in the water or the soil

Question 16

3 waste water treatments

Answer 16

1) primary/physical treatment: sedimentation
2) secondary/biological treatment: aeration
3)disinfection: chemical