Environmental Engineering Reference
In-Depth Information
Experimental Methods
Field Experiment Setup
The experimental setup was located close to a detention pond just outside the City
of Oslo in Norway (early May 2007). This pond receives runoff from a four lane
motorway (E6) with an average daily traffic around 45,000 vehicles. In brief the
pond has a closed pre sedimentation basin in front of the main pond, which has a
wet volume of approximately 800 m
3
and is heavily vegetated from the midpoint
and towards the outlet
[9]
. Veterinary approved brown trout (age 1+), weighing 67.2
± 22.8 g and with a condition factor (K) 1.0 ± 0.1 was supplied from a nearby
hatchery (OFA). The fishes were placed in five experimental tanks (70 L, biomass
30 g/L), maintained in continuously flowing stream water pumped from upstream
the pond outlet from the River Ljanselva (6 L/min) to acclimate before the experi-
ment (5 days). The reference stream water had a temperature of 9.7 ± 0.2°C and a
pH of 7.6 ± 0.1.
To simulate a realistic episode the fish was exposed for a period of 24 h to runoff
water pumped from the inlet (after the pre sedimentation basin) and to the outlet
of the pond, as well as to mixtures of these waters. Thus, the five tanks had the
following pollutant loadings: (1) SW; stream water (control), PI; pond inlet
(untreated runoff), PO; pond outlet (treated runoff), PI + SW; pond inlet + stream
water (mix ratio 50:50), PO + SW; pond outlet + stream water (mix ratio 50:50).
Water Chemistry
Water from each tank was sampled and fractionated in situ with a peristaltic pump
and 0.45 mm membrane filter (Millipore). Two fractions were used throughout the
analyses; particulate fraction (total - 0.45 mm filtrate) and dissolved fraction (0.45
mm filtrate). Determinations of the metals were done by ICP-MS and ICP-OES.
Total organic carbon (TOC), polycyclic aromatic hydrocarbons (16PAH) and hydro-
carbons (C10-C40) were analyzed by ALS Scandinavia. Conductivity, pH, temperature
and oxygen were measured with a multi water quality sensor (W21SDI).
Fish Physiology
After 24 h exposure, six fishes from each tank were sampled randomly. The fish
was killed by a single blow to the head and sampled according to the EMERGE
protocol
[10]
. Blood was immediately sampled from the caudal vein and analyzed
for a total of nine blood parameters; (I-Stat, Abbot), sodium (Na), potassium (K),
