Treatment Plants for Denitrification
Raw
wastewater
Preprecipitation
Primary settling Buffer
tank
tank
Chemically
treated
effluent
Biological sludge hydrolysis
Buffer Dewatered Primary
tank
sludge
sludge
R'-e-t-ur_n.,..~--- Surplus sludge
sludge
Fig7.25 Sketch of the test plant /17/. The model calculations only concern the alternating plant
consisting of the two anoxic/aerobic tanks.
Date
Hour
5HAc
Ss
s,
Xs + Xs.H + Xs,A
x,
{%of COD soluble)
(% of COD particulate)
18/12
09-17
20
70
10
75
25
18/12
17-01
30
60
10
75
25
19/12
01-09
20
70
10
75
25
19/12
09-17
10
80
10
75
25
19/12
17-01
30
60
10
75
25
20/12
01-09
20
70
10
75
25
Table 7,6
Applied fractionation of COD for the influent to the alternating process /16/.
Characterization of the sludge. Based on respiration experiments with oxygen
(OUR), nitrate (NUR) and ammonium oxidation (AUR) /18/, the composition of sludge
is determined by:
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