Fig6.4
Treatment Plants for Nitrification
L
L
SvJ,,= 0
X = 0
X = L
X= 0
X = L
Penetration conditions for two substances if.ex. NH4 + and Oz for nitrification or
N03. and CH30H for denitrification). To the left, substance 1 is limiting due to partial
penetration. To the right substance 2 is limiting.
It depends on the local conditions which of the two expressions for rA,NiS to be used.
A nitrifying filter will often change from oxygen limited nitrification in the inlet to
ammonium limited nitrification later on. In such a case it is possible to make two
separate calculations on the filter, see example 6.2.
Example 6.2
Rotating disc filters for the nitrification of landfill leachate has a total filter area of
40,000 m 2 . The filter is divided in 2 stages, each ideally mixed.
Wastewater characteristics:
a,= 500 m 3 /d
SNH4,1 = 100 g NH4-Nim 3
The oxygen concentration in the two ideally mixed halves of the filter is:
So2,2 = 5 g 02/m 3
So2,4 = 7 g 02/m 3
Each of the 2 filters has a disc area of 20,000 m 2 .
Reaction specific parameters:
k112A,02 = 4 (g 02) 112 m- 112 d- 1
201