Advances in Understanding Mobilization Processes of Trace Metals in Marine Sediments

• DOI: 10.1021/acs.est.0c05954
• Publication Date: 2020-11-10T22:01:34Z
• Authors: Chunyang Zhou; Yue Gao; Camille Gaulier; Mingyue Luo; Xiaohan Zhang; Arne Bratkic; William Davison; Willy Baeyens
• Keywords: Sediment–water interface

Different mobilization mechanisms control the metal distribution in surface sediments of Belgium coastal zone (BCZ) and anoxic Gotland basin (GB). This was studied using DGT (diffusive gradients thin films): vertical one-dimensional (1D) profiles Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn were measured at 5 mm intervals, while two-dimensional (2D) high-resolution (100 μm) images smaller zones sediment profile obtained on separate probes. Removal dissolved Pb BCZ caused steep sediment–water interface that well replicated 1D 2D images. While showed apparent coincident maxima revealed mutually exclusive Co Fe mobilization. Correlation analysis supported this observation a consistent linkage between Mn. Sharp some metals GB attributed to localized microniches. Examination an ∼1 diameter Cu Ni maximum 2D, defined by ∼300 data points, supplied from decomposition reactive organic material, rather than reductively dissolving or Mn oxides, they removed as their sulfides.