Effect of Decing Salts on Ion Concentrations in Urban Stormwater Runoff

Stormwater draining from impervious surfaces in urban areas often contains readily soluble salts in runoff, which contribute dramatically to the degradation of aquatic ecosystem. The concentrations of potassium (K), cadmium (Ca), sodium (Na), magnesium (Mg), chloride (Cl) and sulfate (SO42-) in stormwater runoff in the urban areas of Shenyang city were measured in 4 rainfall events during July 2009 to June 2010. The results showed that there was an obvious increasing of salt ions concentrations in stormwater runoff samples, especially Na and Cl. It is also found that readily soluble salts ions in stormwater runoff peaked at the first storm event after winter. This study demonstrated that the applied deicing salts in winter significantly contributed to the increasing concentrations of K, Ca, Na, Mg, Cl, and SO42- in urban stormwater runoff. It is evident that the application of deicing salts in cold regions of China every year has had adverse impacts on the aquatic ecology through stormwater runoff.