Download 5.2 Detection and monitoring of pollution

Water Quality & Soil Quality IA
• Class Lab: Practice testing soil (Activity 2)
– Acidity
– Nitrogen
– Potassium
– Phosphate
• Class Lab: Investigate how water pollutants are measured
(Activity 6)
• You will also be provided with detailed instructions on
how to test water samples for major pollutants (Activity
7). However due to time and only a limited supply of
materials, we will not do the water testing as class lab.
• With the materials Ms. Simmons has as well as outside
resources, you must plan, design and execute your lab.
• No group data collection!
• You will be working independently
Water Quality & Soil Quality IA
Option 1: Water Quality Effects on Plant Life
Plan an investigation looking at how water quality
or pollution levels may affect plant life or growth.
The reverse can also be applied as plants can be
used as indicators of water quality or pollution
levels (indirect method). Some suitable plant life
that can be easily obtained include elodea and
duckweed (lemnoideae). Some examples of
pollutants/testing variables: oil, metals (copper),
pesticides, fertilizers (nitrates/phosphates/acidity),
chlorine, dissolved oxygen.
Water Quality & Soil Quality IA
Option 2: Soil Quality/Biochemistry Effects on
Species Diversity
Investigate various soil samples from different
locations and analyze the chemical characteristics
to determine how soil composition affects species
diversity. You can look at biodiversity as a whole or
focus on the abundance of a particular organism
such as plants, bacteria, fungi, or other small
microorganisms. Examples of chemical components
to test: acidity, nitrates, potassium, phosphate.
5.2 Detection and monitoring of
pollution
Detection and Monitoring
• Environmental monitoring describes the
processes and activities that need to take
place to characterize and monitor the quality
of the environment.
• Used in the preparation of environmental
impact assessments, as well as in many
circumstances in which human activities carry
a risk of harmful effects on the natural
environment.
Direct Measurement
• Direct measurement is performed by
monitoring the level of the pollutant itself, e.g.
nitrates in a lake or temperature levels in a
lake or stream.
Direct methods of monitoring
pollution
• Air pollution
• Measure the acidity
of rain water to
determine pH
• Measure CO2, CO,
or NOx levels in the
atmosphere using a
gas sensor
• Measure particulate
matter suspended
in the atmosphere
Direct methods of monitoring
pollution
– Soil pollution
• Test for nitrates and phosphates (Using
LaMotte test kits)
Direct methods of monitoring
pollution
– Water pollution
• nitrate and phosphate tests
• fecal coliform tests
• tests for heavy metals (Hg, Pb, As)
Indirect Measurement
• Monitor the effects of the pollutants on other
factors, e.g. dissolved oxygen, B.O.D., presence or
absence of indicator species
• Involves the monitoring and measurement of
organisms in the ecosystem and more specifically
indicator species or index species.
• These are species that by virtue of their abundance
or absence will indicate the level of pollution in that
ecosystem.
– For example: leafy lichens on trees if the air is
unpolluted
BOD (Biochemical Oxygen Demand)
 BOD is an indirect method that measures the
amount of oxygen required to support respiration
by organisms living in a water sample.
• high BOD indicates there are many organisms
using oxygen for respiration
• low BOD indicates relatively few organisms
needing oxygen for respiration
• high BOD = low DO levels = high pollutant levels,
especially nitrate & phosphate
• low BOD = high DO levels = low pollutant levels
The Biotic Index
• Biotic Index – An indirect method
that uses a 1-10 scale by observing
the presence or absence of key
organisms to indicate the relative
level of pollution in an ecosystem
(example: stream).
• The Trent Biotic Index is based on
the fact that certain species tend to
disappear and the species diversity
decreases as the organic pollution in
a water course increases.
• The scale corresponds to the four
basic water quality (Excellent, Good,
Fair or Poor).
How does it work?
• The biotic index works by assigning different levels of tolerance to
pollution to the different types of organisms. The types of
macroinvertebrates found during sampling are grouped as:
1: Pollution intolerant: These organisms are highly sensitive to
pollution. (e.g. stonefly or alderfly larva)
2: Semi-Pollution intolerant: These organisms are sensitive to
pollution. (e.g. dragonfly larva or crawfish)
3: Semi-Pollution tolerant: These organisms will be found in clean
and slightly polluted waterways. (e.g. snails or black fly larva)
4: Pollution tolerant: These organisms will be found in polluted, as
well as clean aquatic ecosystems (e.g. leeches,bloodworms)
Pollution Semi-Pollution
Tolerant Tolerant
Pollution
Intolerant
Indicator Species
• Species that are present
either only in polluted
areas or only in
unpolluted areas.
– Lichens – Not present in
air pollution
– Rat-tailed maggot and
sludge worms – Found
only in polluted water
– Gammarus - small
crustaceans that are not
found in high levels of
salinity.
The Biotic Index (cont)
• Advantages:
– Easy to use, especially for moderately or heavily polluted
sites
– The pollutants are not measured directly but their effect
on biodiversity is measured.
– Aquatic macroinvertebrates are often used as an indicator
because they have some general characteristics that make
them very useful to assess stream health:
• abundant and found in water bodies throughout the world
• not extremely mobile
• carry out part or all of their life cycle within the stream or river
• Disadvantages:
– not specific enough
– doesn’t fully account for habitat quality
How Water Pollutants are Measured
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Activity 6 (page 20)
Get in groups of 4 (3 groups will have 5 people)
One group per lab bench
Make sure you have 2 plastic pipets, one red cup, one clear
cup, one white cup with red dye, and one spot plate
• Fill the red cup and clear cup with water
– The clear cup will be used for the water you initially drop in each
well #1-5 (Steps 2 & 3)
– The red cup will be used to flush the pipet before transferring
drops between wells (Steps 4 & 5)
• Read instructions carefully and complete Data Table 6
• When finished with lab, please RINSE and RETURN the
clear cup, red cup, spot plate and pipets.
• You may throw the small white cup away.