The presentation provides a brief background on phosphorus, introduces phosphates, gives examples of forms of phosphates. It further describes how to test for the forms of phosphates as well as how to regulate water phosphate level. It ends with some basic facts "Did you know".

1. 30-Jun-14
PHOSPHATE AS A
WATER QUALITY
PARAMETER
By
Kumeh Mensah Eric
BSc. Natural Resource Mgt.
(Agroforestry)
KNUST
Ghana

2. 30-Jun-14
Presentation Outline
 Background
 Forms of Phosphate
 Uses of Phosphate
 The Phosphorus Cycle
 Effects of Phosphate on Aquatic Life
 Testing for Phosphate
 Phosphate level and its effect on aquatic
plants life
 Regulating Phosphate Levels in Water
 Relationship between phosphate and some
water quality parameters
 Did you know ?

3. 30-Jun-14
Background
 Phosphorus - a primary element
in phosphate, is an essential
nutrient for all plants and
animals.

4. 30-Jun-14
Background
 What are phosphates ?
 Phosphates are the salts of various
phosphoric acids.
Crystals of Ammonium
phosphate

5. 30-Jun-14
Forms of Phosphate
1.Orthophosphates (H2PO4
-/HPO4
2-)
Simple ionic forms of phosphates that are
readily available to plants.

6. 30-Jun-14
Forms of Phosphate
2. Polyphosphates (PolyP) - (PHO3)n
 A linear, unbranched polymer of
orthophosphate residues linked
by phosphoanhydride bonds.
 PolyP ranges in size from three
to over one thousand
orthophosphate residues.
Brewers yeast

7. 30-Jun-14
Uses of Phosphate
 Animal feed supplements
 Fertilizers
 Water treatment

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Uses of Phosphate
 Domestic and industrial detergents
 Metal treatment to inhibit
corrosion
 Ceramic production

9. The phosphorus cycle
30-Jun-14

10. 30-Jun-14
Effects of Phosphorus on Aquatic Life
 Aquatic plants require phosphates to grow
and carry out metabolic reactions.
 Phosphates often serve as the limiting factor
for aquatic plant growth because they
naturally occur only in very low
concentrations of 0.03 parts per million (ppm)
or less.
 When the phosphates level in a certain body
of water reaches 0.025 ppm and above,
phosphates stimulate plants to grow more
rapidly.

11. 30-Jun-14
Effects of Phosphorus on Aquatic Life
 An increase in phosphates and other nutrients
that increases the rate of plant growth
eventually results in dead plant matter
building up in the water.
 A condition know as Eutrophication (Algae
bloom)

12. 30-Jun-14
Effects of Phosphorus on Aquatic Life
 Eutrophication decrease the amount of
sunlight in water bodies and increase the
concentration of carbon dioxide when algae
die and decompose.
 Increasing carbon
dioxide deprive
aquatic organisms
of oxygen and
eventually result in
asphyxiation of fish
and other
organisms.

13. 30-Jun-14
Testing for phosphates
 Total Orthophosphate Test
 A measure of dissolved and suspended
orthophosphate.
 EPA approved ‘Ascorbic Acid Method’,
 A reagent (either liquid or powder)
containing ascorbic acid and
ammonium molybdate reacts with
orthophosphate in the sample to form
a blue compound. The intensity of the
blue colour is directly proportional to
the amount of orthophosphate in the
water.

14. 30-Jun-14
Testing for phosphates
 Total Phosphorus Test
 Measures all the forms of phosphorus in the
sample (orthophosphate, condensed
phosphate, and organic phosphate)
Procedure
 “Digesting" (heating and acidifying) the sample to
convert all the other forms to orthophosphate.
 Measure orthophosphate using the ‘ascorbic acid
method’.
NB: Because the sample is not filtered, the
procedure measures both dissolved and suspended
orthophosphate.

15. 30-Jun-14
Testing for phosphates
 Dissolved phosphorus test
 Measures that fraction of the total phosphorus
which is in solution in the water (as opposed to
being attached to suspended particles).
 It is determined by first filtering the sample,
then analysing the filtered sample for total
phosphorus.
 Insoluble Phosphorus is calculated by
subtracting the dissolved phosphorus result from
the total phosphorus result.

16. 30-Jun-14
Phosphate level and its effect on aquatic plants
life
Total Phosphate Effects on aquatic plant
growth
0.025 - 0.1 mg/L Adequate stimulation of
plant growth
0.1 mg/L
maximum acceptable limit
to prevent accelerated
eutrophication
> 0.1 mg/L
accelerated growth and
consequent problems

17. 30-Jun-14
Regulating Phosphate Levels in Water
 Addition of chemicals
 Coralife's Phosphate Remover,
 Sea Chem's PhosGuard
 Kent Marine's Phosphate Sponge

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Regulating Phosphate Levels in Water
 The use of poly – filter pads

19. 30-Jun-14
Regulating Phosphate Levels in Water
 “Vodka Method” + Protein Skimmer

20. 30-Jun-14
Regulating Phosphate Levels in Water
 Repetitive water change

21. 30-Jun-14
Relationship between phosphate and some
water quality parameters
 Water Phosphates and Turbidity
 Increasing phosphate concentration in water
increases turbidity in the long-run.

22. 30-Jun-14
Relationship between phosphate and some
water quality parameters
 Increasing amount of phosphates reduces pH
making water more acidic in the long-term.
 Water Phosphate and pH

23. 30-Jun-14
Relationship between phosphate and some
water quality parameters
 Increasing Phosphate
reduces dissolve Oxygen
content.
 Water Phosphate and Dissolved Oxygen
OXIX® DISSOLVED
OXYGEN TRANSMITTER

24. 30-Jun-14
Did You Know ?
 Phosphorous was discovered by
Henning Brand in 1669 when he
distilled pure urine.

25. 30-Jun-14
Did You Know ?
 Matchsticks are soaked in ammonium phosphate,
which is a fire retardant to prevents them from
smouldering after the match has gone out

26. 30-Jun-14
Did You Know ?
 Phosphate molecule make up the base of a DNA

27. 30-Jun-14
Thank You
Please help me improve on the
content by posting your comments
or by sending them to:
elmensinho@gmail.com or
elmensinho11@hotmail.com

28. 30-Jun-14
References
 http://www.madehow.com/Volume-
3/Match.html#b date accessed 24th June, 2014.
 http://www.macalester.edu/academics/environ
mentalstudies/threerivers/studentprojects/ENV
I_133_Spr_08/Phosphorus/Phosphorus%20Effects
%20Webpage.html date accessed 24th June,
2014.
 http://www.waterresearch.net/Watershed/pho
sphates.htm 25th June, 2014.
 http://www.stevenswater.com/articles/waterp
arameters.aspx 25th June , 2014.
 http://www.freedrinkingwater.com/water_qual
ity/quality1/1-what-nitrate-and-phosphate-
do.htm 25th June, 2014.