Environmental Engineering Reference
In-Depth Information
The objective of this study is to investigate how addition of aluminum affects the
toxicity of stormwater runoff. The toxic effect is estimated applying three different
toxicity tests. The results of the study can be applied to determine whether addition
of aluminum to wet detention ponds can reduce the toxic effect of stormwater by
adding similar quantities of aluminum as typically used to remove phosphorous
from the water phase.
Method
Collection and Storage of Samples
Stormwater runoff samples were collected from a wet detention pond located in the
southern part of Odense, Denmark. The wet detention pond is constructed as a part of
the EC LIFE-treasure project
[7]
and is placed in a green area next to a catchment with
light industry and associated roads (Fig.
1
). The catchment has an area of 27.4 ha of
which 11.4 ha are impervious, resulting in an estimated runoff of 55,500 m
3
/year.
The stormwater runoff is pretreated in a grit chamber before entering the pond.
Stormwater runoff for analysis was collected from the center of the pond. The samples
were collected in glass bottles over a 2 month period and stored at 5°C until analysis.
Preparation of Samples Prior to Analysis
Four samples were collected over a 2 month period, two samples in February 2008
(sample I and II) and two at the beginning of April 2008 (sample III and IV). Due
to a natural content of microalgae in the samples, the samples where filtrated
Wet detention pond
Fig. 1
Wet detention pond from where
the samples were collected. The appurte-
nant catchment is outlined
