Avskiljningsförmåga hos dagvattendammar i relation till dammvolym, bräddflöde och inkommande föroreningshalt / Reduction efficiency in stormwater ponds in relation to pond volume, overflow and inflow pollutant concentration
This article puts forward the idea that the reduction efficiency in a stormwater pond to a great extent can be explained by three parameters related to the pond:
– The size of the pond in relation to its catchment area
– The relative size of the possible overflow past the pond
– The mean concentration of suspended solids in the incoming flow
To support the thesis field data from twelve Swedish stormwater ponds is presented. Data and results are presented for suspended solids, lead, copper, phosphorus and nitrogen. In addition zinc, chromium, nickel and cadmium have also been studied with similar results. A correlation between relative pond size and reduction efficiency has been demonstrated for all substances examined after accounting for overflow. A correlation has also been demonstrated between reduction of suspended solids and reduction of metals and nutrients.
A simple numerical model has been established in an attempt to estimate how different incoming concentrations of suspended solids and different overflow situations might affect the reduction. The input required by the model are relative pond size, size of possible overflow and mean concentration of suspended solids in the incoming water. The model has been validated by field data from the examined ponds with fairly good result.