Mercury and arsenic mobility in resuspended contaminated estuarine sediments (Asturias, Spain): A laboratory-based study.

摘要: Abstract Estuarine sediments must be dredged to allow for navigation, and where these are placed after dredging depends upon guidelines based only on the total concentration of contaminants. However, resuspension events could seriously affect mobility speciation contaminants, including potentially toxic trace elements stored in sediments. The effects cycling mercury (Hg) arsenic (As) between sediment water column was investigated a mesocosm study. Four experiments were conducted three estuaries northern Spain samples collected from sites which have been impacted by decommissioned Hg As mines periodically subjected activities. Designed mimic particles, each revealed that release species does not depend (16.3–50.9 mg kg−1, 0.52–5.01 mg kg−1 Hg). contribution porewaters subsequent reductive dissolution and/or desorption appear main processes responsible abrupt increase dissolved (maximum 427% 125%, respectively). In some cases, continued remain at high concentrations even completed, thus testifying their critical persistence form. Conversely, other sites, restoration pre-resuspension conditions observed few hours resuspension, mainly due role Fe oxy-hydroxides provides suitable surfaces adsorption co-precipitation involving removal −58%) −25%) species. results this research helpful take appropriate decisions regarding especially Nalon estuary, As(V) MeHg appeared favoured resuspension.