Turbidity
Definition:
Turbidity
is the measure
of the relative clarity of water.
Importance:
Murkiness can give some clues to
what may be in the water. There may be dissolved pollutants or bacteria. However, murky water does
NOT necessarily mean there is pollution.
Steps
for measuring turbidity:
1.Pour
the collected sample water into
the white container.
2.Compare the appearance of Secchi
disk icon in the container to the chart.
Precautions
taken to ensure accuracy of readings:
•Fill
up the container to the turbidity line located on the label. Record the result
as turbidity in JTU.
Dissolved
Oxygen
Definition:
The dissolved oxygen is the amount
of oxygen dissolved in
a given volume of water, at a given temperature and atmospheric pressure.
This can be measured in
milligrams per litre (mg/l) or parts per million (ppm).
Importance:
The amount of dissolved oxygen
needed
to sustain fish life is about 4
mg/l or 4 ppm.
Steps for measuring dissolved oxygen:
1. Fill the vial with the water collected.
2. Ensure no bubbles visible
3. Insert 2 tablets for dissolved oxygen testing
4. Close the cover
5. shake continuously for 10 mins
6. Observe colour change and compare colour against the dissolved oxygen chart.
Precautions
taken to ensure accuracy of readings for dissolved oxygen:
•Vial
must be submerged into the white container while filling the vial with
collected water. This is to
avoid introducing bubbles in the vial.
•Always
place the vial or test tube
against the white background when comparing collected water
with the given chart.
PH value
Definition:
It
is a measurement of acidity or alkalinity of an aqueous solution.
Importance:
Most
aquatic animals prefer a range of pH 6.5 to 8.0.
pH
can be affected by acid rain or wastewater discharges
If
the living conditions have a pH value away from this range, these aquatic
animals will either flee or die.
Steps for measuring PH value:
1. Fill the test tube up to the 10 ml mark
2. Insert a PH tablet into the test tube.
3. Observe colour change and compare colour against the PH chart.
Precautions
taken to ensure accuracy of readings:
•Always
place the test tube against the white background
when comparing collected water with the given chart.