1 “Modelling and mapping of copper runoff for Europe”
I. Odnevall Wallinder, B. Bahar, C. Leygraf and J. Tidblad Journal of Environmental Monitoring, 9, 66-73, 2007.
2 "Predictive models of copper runoff from external structures"
I. Odnevall Wallinder, S. Bertling, X. Zhang, and C. Leygraf, Journal of Environmental Monitoring, 6, 704-712, 2004.
3 "Long term corrosion-induced copper runoff from natural and artificial patina and its environmental fate" S. Bertling,
I. Odnevall Wallinder, D. Berggren and C. Leygraf, Environmental Toxicology and Chemistry, 25(3), 891-898, 2006.
As an example, the predicted runoff rate of g/(m2,year) is valid for a m2 copper roof, this equals g of Cu released per day. If the predicted amount of copper runoff reaches a river that is m deep and m from one shore to the other with a water mass flow of m/sec = m3/day, the added copper concentration from the runoff water to the river is µg Cu/L.
|Copper released from tapwater systems in Stockholm: 4300 kg / year|
|Copper released from traffic in Stockholm: 5700 kg / year|
CORROSION-INDUCED COPPER RUNOFF
FROM EXTERNAL CONSTRUCTIONS
Predicted runoff rate: g/m2,year
! The total copper runoff rate is not a direct measure of any environmental effect.
The annual rain quantity varies typically within the range of 400-3200 mm/year depending on geographical differences.
Stockholm, Sweden - 500 mm/year
Singapore, Singapore - 3000 mm/year
Davos, Switzerland - 1200 mm/year
! Prevailing rain characteristics influence the runoff rate. For instance, high rain intensity usually means short contact time with the copper surface, which results in lower copper runoff and vice versa.
Rain pH is a measure of the rain acidity. The copper runoff increases with decreasing pH and vice versa.
Stockholm, Sweden - pH 4.6
Singapore, Singapore - pH 4.4
Davos, Switzerland - pH 5.9
! Rain pH is, for instance, influenced by acidifying pollutants such as H2SO4 and HNO3.
SO2 is a known gaseous pollutant that stimulates the corrosion of copper.
Stockholm, Sweden - 3 µg/m3
Singapore, Singapore - 22 µg/m3
Davos, Switzerland - 1.3 µg/m3
! The SO2-concentration is often reported in parts per billion, ppb. 1 µg/m3 = 2.64 ppb