Treatment Plants for Phosphorus Removal from Wastewater
5.0
4.0
3.0
2.0
1.0
8.0
3.0
2.0
Dissolved phosphate
(gP/Fn3)
\\ \
\ ,\ \
1 \
'
\ \
1\
~\ 1 \
\' ,\
,,
~\ \
\ \\
~\ \.
ca••
2b -
1 / 40 _
"
Fe/P = 1 / ~ 60
['. ......
,....,. ~ v g/m3
I "' r--.
v
ca++
120 -
A 40 -
60 _
I.
1.0
~
Fe/P - 1.5 /.~
'fg/ml 3_
0.0
~ ~
~ ~
4.0
3.0
2.0
1.0
1-- ca++
I
I
20
..d
r--40 1~ t'-.
Fe/P = 2
A~
r--60 ~~
I I
~
r- g/m3
~
....::
0.0
4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 pH
Fig 10.24 Simultaneous precipitation with ferrous sulphate, Fe(ll). Dissolved phosphate as a
function of pH and calcium for varying Fe/P-molar ratios: 1.0, 1.5 and 2.0. /4/
The concentration of suspended solids (particles) in the effluent from the final
settling is not solely determined by the flocculation, but to a large extent also by the
design of the settling tank and the properties of the suspended solids.
Based on experience, figures found for the concentration of suspended solids -see
Table 10.6- and the phosphorus content in the suspended solids, the concentration
of suspended phosphorus in the effluent, Xp, can be determined.
The phosphorus content in the suspended solids can be determined by means of a
sludge balance as illustrated in Example 10.1.
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