%of time
100
90
80
70
60
50
40
30
20
10
0+--r--r-~~--~~--r-~~--~~--r-~~--~~
5.000
10.000
15.000
19.000
kg/d
Fig 1.11 Fractile diagram for influent of BOD and COD to Lundtofte wastewater treatment plant (Denmark). On this basis the load to be considered for the design can
be determined. Maximum design load can for example be determined corresponding to the 85% fractile. Data from /24/
15
..
liD!+
10
IlllA'\
• •
~
5
•
S111holt Wastewater Treatment Plant, Denmark
+ Frederikssund Wastewater Treatment Plant, Denmark
0+------.----~-----,.-----~----.------,
Jan-85
Jan-86
Jan-87
Jan-88
Fig 1.12 Temperature variation in activated sludge tanks, Seholt and Frederikssund
wastewater treatment plants (Denmark) /23/
33