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The effects of pH and
temperature on phosphate and nitrate uptake by wastewater
protozoa
Akpor, O. B., Momba, M. N.
B.* and Okonkwo, J. O.
Department
of Environmental, Water and Earth Sciences, Tshwane
University of Technology, P/Bag X680, Pretoria, 0001, South
Africa.
*Corresponding author. E-mail:
mombamnb@tut.ac.za.
Accepted
14 May, 2008 |
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The objective of this study was to ascertain the effects of
pH and temperature on nutrient uptake efficiency of 3
wastewater protozoan isolates (Aspidisca (A),
Trachelophyllum (B) and Peranema (C)) that
have previously been screened for nutrient uptake ability.
The study was carried out in shake flask at pH 5, 6, 7, 8
and 9 and incubation temperatures of 25, 30 and 35oC
for 96 h. The results revealed optimum pH ranges for the
uptake of phosphate and nitrate to be 7 to 9 and 5 to 7,
respectively. Maximum nutrient uptake was found to occur at
25oC with phosphate concentration decreasing from
64.74 to 10.21 mg/l, 63.09 to 8.54 mg/l and 64.47 to 6.36
mg/l, for isolates ‘A’, ‘B’ and ‘C’, respectively. Also,
nitrate concentration was found to decrease from 24.71 to
4.91 mg/l for isolate ‘A’, 24.47 to 11.15 mg/l for isolate
‘B’, and 24.58 to 15.00 mg/l for isolate ‘C’ at the same
temperature. An increase in COD was observed in mixed liquor
inoculated with the test isolates. The study has been able
to give an insight into the optimum temperature and pH for
phosphate and nitrate uptake by the isolates.
Key
words:
Nitrate, pH, phosphate, temperature, uptake. |
