Impact of Urban Stormwater on Sediment Quality in an Enclosed Bay of the Lule River, Northern Sweden

Abstract

Sediment and porewater samples from an enclosed bay receiving stormwater discharge (Skutviken) near the centre of Luleå, northern Sweden were analysed for major and trace elements and 16 polycyclic aromatic hydrocarbons (PAHs). Among the studied metals Cd, Cu, Pb and Zn were enriched at Skutviken. Also, the PAH content was enriched, in particular for phenantrene, anthracene, fluoranthene and pyrene which are regarded as common constituents in stormwater. The use of trace metal ratios provided indications about pollutant sources for the sediment. Cs-137 dating was used to determine historical changes in metal and PAH fixation in the sediment. The bay Skutviken is enclosed through the construction of a road bank since 1962. The enclosure led to reduced water circulation in the bay that promotes the occurrence of anoxic conditions with sulphate reduction within the bay. As a consequence of these conditions, metals are trapped in the sediments as sulphides. This study suggests that enclosed bays with restricted water circulation may be efficient traps for urban pollutants, reducing the present-day input of pollutants to the sea. In areas with postglacial land uplift, where such bays are common, bay sediments are a potential future source of pollutants when uplift results in erosion and oxidation of the sediments.

Thermal plasma treatment of stormwater sediments: comparison between DC non-transferred and partially transferred arc plasma

“…[4][5][6][7] Based on these studies, it can be concluded that most of the stormwater sediments are contaminated by heavy metals, phosphorus, trace organic and hydrocarbon and cannot be disposed of without treatment. [5][6][7][8][9][10] Generally, the current disposal treatment options fall into one of three different types, namely (1) biological; (2) chemical/immobilization; and (3) thermal processes. A wide variety of organics and heavy metals associated with stormwater sediment was reported.…”

Assessment of stormwater discharge contamination and toxicity for a cold-climate urban landscape

“…Mayer et al [ 51 ] observed that aqueous PAHs were below instrument detection limits and that 91% of PAHs were particulate-bound. Particle-bound PAHs tend to have high molecular weight [ 4 , 27 , 49 , 64 , 81 ], while low-molecular-weight PAHs predominantly are found in dissolved phases [ 27 ]. This would explain some of the unremarkable PAH concentrations found in filtered SW samples, especially high-TSS August 22 samples, as the bulk of PAHs would remain within the filter sediment.…”

Polymer-assisted hydraulic dredging for quality control of stormwater pond sediment and reject water – Influence of polymer choice and its preparation

“…The accumulated sediment in the ponds has entrained pollutants for typically decades before being removed in a dredging operation. Therefore, sediment in wet ponds usually contains high levels of multiple pollutants [6,7] but also exhibits significant heterogeneity in the types and levels of accumulated pollutants between ponds [8]. Dredging operations move the accumulated sediment from one environment to another.…”