Characterization of heavy metal desorption from road-deposited sediment under acid rain scenarios
Bo Zhao , An Liu , Guangxue Wu , Dunzhu Li , Yuntao Guan
DOI:10.1016/j.jes.2016.05.032
Received November 27, 2015,Revised May 23, 2016, Accepted May 26, 2016, Available online July 18, 2016
Volume 29,2017,Pages 284-293
Road-deposited sediments (RDS) on urban impervious surfaces are important carriers of heavy metals. Dissolved heavy metals that come from RDS influenced by acid rain, are more harmful to urban receiving water than particulate parts. RDS and its associated heavy metals were investigated at typical functional areas, including industrial, commercial and residential sites, in Guangdong, Southern China, which was an acid rain sensitive area. Total and dissolved heavy metals in five particle size fractions were analyzed using a shaking method under acid rain scenarios. Investigated heavy metals showed no difference in the proportion of dissolved fraction in the solution under different acid rain pHs above 3.0, regardless of land use. Dissolved loading of heavy metals related to organic carbon content were different in runoff from main traffic roads of three land use types. Coarse particles (> 150 μm) that could be efficiently removed by conventional street sweepers, accounted for 55.1%–47.1% of the total dissolved metal loading in runoff with pH 3.0–5.6. The obtained findings provided a significant scientific basis to understand heavy metal release and influence of RDS grain-size distribution and land use in dissolved heavy metal pollution affected by acid rain.
