Contamination by urban superficial runoff: accumulated heavy metals on a road surface

Abstract

Studying the behaviour of accumulated contamination on urban surfaces is important in designing control methods minimising the impacts of surface runoff on the environment. This paper presents data regarding the sediment collected on the surface of an urban road in the city of Torrelavega in northern Spain during a period of 65 days during which 132 samples were collected. Two types of sediment collection samples were obtained: vacuumed dry samples (free load) and those swept up following vacuuming (fixed load). The results showed that heavy metal concentration in the collected sediment (Pb, Zn, Cu and Cd) was inversely proportional to particle diameter. High heavy metal concentrations were found in the smaller fraction (63 pm). Regression equations were calculated for heavy metal concentration regarding particle diameter. Large heavy metal loads were found in the larger fraction (125 pm). The results provide information for analysing runoff water quality in urban areas and designing treatment strategies.

Keywords

• heavy metals
• urban superficial runoff
• urban dirt
• superficial load
• concentration
• sediment
• particle sized distribution