| 1. |
- Viklander, Maria
(författare)
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Snow quality in the city of Lulea, Sweden : time-variation of lead, zinc, copper and phosphorus
- 1998
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Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 216:1-2, s. 103-112
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Tidskriftsartikel (refereegranskat)abstract
- The quality of urban snow was studied with regard to how the concentrations of selected metals and phosphorus vary over time. The area studied is situated in northern Sweden (65°36 prime N; 22°13 prime E). Snow samples were taken at three different locations in the city centre, approximately every second week, throughout winter. This study has clearly shown the importance of local conditions and snow clearance operations on snow quality. The study also shows that it is difficult to interpret and predict the concentrations of lead, zinc, copper and phosphorus in the snow. However, it should be possible to predict the mass loads of these substances from the deposition velocities, if the snow handling methods and routines, as well as the local circumstances are known.
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| 2. |
- Viklander, Maria
(författare)
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Urban snow deposits : pathways of pollutants
- 1996
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 189-190, s. 379-384
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Tidskriftsartikel (refereegranskat)abstract
- The pathways of pollutants in urban snow deposits have been studied in the laboratory, in a pilot study and at an actual deposit. The fractions of dissolved and particle-bound substances in the snow and melt water were studied. The results showed that almost all substances in the snow were attached to particles, while in the melt water more than 50% of most substances were dissolved. A large part of the substances which were attached to particles stayed in the sediment below the deposit, while the dissolved substances were mainly removed with the melt water.
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| 3. |
- Beryani, Ali, et al.
(författare)
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Performance of a gross pollutant trap-biofilter and sand filter treatment train for the removal of organic micropollutants from highway stormwater (Field study)
- 2023
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 900
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Tidskriftsartikel (refereegranskat)abstract
- This field study assessed the occurrence, event mean concentrations (EMCs), and removal of selected organic micro-pollutants (OMPs), namely, polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs), nonylphenol (NP), 4-t-octylphenol (OP), and bisphenol A (BPA), in a gross pollutant trap (GPT)-biofilter/sand filter stormwater treatment train in Sundsvall, Sweden. The effects of design features of each treatment unit, including pre-sedimentation (GPT), sand filter medium, vegetation, and chalk amendment, were investigated by comparing the units' removal performances. Overall, the treatment train removed most OMPs from highway runoff effectively. The results showed that although the sand filter provided moderate (<50 % for phenolic substances) to high (50–80 % for PAHs and PHCs) removal of OMPs, adding a vegetated soil layer on top of the sand filter considerably improved the removal performance (by at least 30 %), especially for BPA, OP, and suspended solids. Moreover, GTP did not contribute to the treatment significantly. Uncertainties in the removal efficiencies of PAHs and PHCs by the filter cells increased substantially when the ratio of the influent concentration to the limit of quantification decreased. Thus, accounting for such uncertainties due to the low OMP concentrations should be considered when evaluating the removal performance of biofilters.
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| 4. |
- Borris, Matthias, et al.
(författare)
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Contribution of coarse particles from road surfaces to dissolved and particle-bound heavy metal loads in runoff : A laboratory leaching study with synthetic stormwater
- 2016
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 573, s. 212-221
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Tidskriftsartikel (refereegranskat)abstract
- Laboratory leaching experiments were performed to study the potential of coarse street sediments (i.e. > 250 μm) to release dissolved and particulate-bound heavy metals (i.e. Cd, Cr, Cu, Ni, Pb and Zn) during rainfall/runoff. Towards this end, street sediments were sampled by vacuuming at seven sites in five Swedish cities and the collected sediments were characterized with respect to their physical and chemical properties. In the laboratory, the sediments were combined with synthetic rainwater and subject to agitation by a shaker mimicking particle motion during transport by runoff from street surfaces. As a result of such action, coarse street sediments were found to release significant amounts of heavy metals, which were predominantly (up to 99%) in the particulate bound phase. Thus, in dry weather, coarse street sediments functioned as collectors of fine particles with attached heavy metals, but in wet weather, metal burdens were released by rainfall/runoff processes. The magnitude of such releases depended on the site characteristics (i.e. street cleaning and traffic intensity), particle properties (i.e. organic matter content), and runoff characteristics (pH, and the duration of, and energy input into, sediment/water agitation). The study findings suggest that street cleaning, which preferentially removes coarser sediments, may produce additional environmental benefits by also removing fine contaminated particles attached to coarser materials
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| 5. |
- Furén, Robert, Industridoktorand, et al.
(författare)
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Occurrence, concentration, and distribution of 38 organic micropollutants in the filter material of 12 stormwater bioretention facilities
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 846
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Tidskriftsartikel (refereegranskat)abstract
- The increased use of bioretention facilities as a low impact development measure for treating stormwater runoff underscores the need to further understand their long-term function. Eventually, bioretention filter media must be (partly) replaced and disposed of at the end of its functional lifespan. While there are several studies of metal accumulation and distributions in bioretention media, less is known about organic pollutant pathways and accumulation in these filters. The present study considers the occurrence and accumulation of 16 polycyclic aromatic hydrocarbons, 7 polychlorinated biphenyls, 13 phthalates, and two alkylphenols throughout 12 older bioretention facilities (7–13 years old) used for stormwater treatment in Michigan and Ohio, USA. These pollutant groups appear to behave similarly, with greater instances of detection and higher concentrations in the upper media layers which decrease with increased depth from the surface. The patterns of detection and concentration in the filter material may be explained by characteristics of the pollutants, such as molecular structures and solubility that affect the removal of the organic pollutants by the filter material. There is also a large variation in concentration magnitudes between the bioretention sites, most likely due to differences in pollutant sources, contributing catchment size and/or land uses.
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| 6. |
- Gavrić, Snežana, et al.
(författare)
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Metal enrichment of soils in three urban drainage grass swales used for seasonal snow storage
- 2021
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 760
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Tidskriftsartikel (refereegranskat)abstract
- Enrichment of soils in three urban drainage swales by metals associated with traffic sources was investigated in a cool temperate climate with seasonal snow. Such swales differed from those not exposed to snow by receiving additional pollutant loads from winter road maintenance involving applications of salt and grit, use of studded tires, and storage and melting of polluted snow cleared from trafficked areas into swales. Among the swales studied, swale L2 in the downtown was the oldest (built around 1960), drained runoff from a road with the highest traffic intensity, and exhibited the highest mean concentrations of most of the metals studied (Pb, Cu, Zn, Cr, Cd, Ni, Co, V, Ti, and W). In the case of Pb, this exceedance was about an order of magnitude: 71 mg/kg DW in L2, compared to about ~8 mg/kg DW in L1 and L3, both built in 1979. Among the metals originating from local geology, barium (Ba) was found in the swales and the grit material at high concentrations of ~650 mg/kg DW and 700–1000 mg/kg DW, respectively. Such concentrations exceeded the Swedish EPA guideline limits of 300 mg/kg DW for less sensitive soil use. The sequential extraction analysis of samples from swale L2 indicated that Ba was mostly in the immobile residual fraction (90%). The absence of clear decline in metal concentrations with distance from the trafficked surfaces suggested that stored snow was another source of metals partly balancing spatial distribution of metals in swale soils.
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| 7. |
- Gavric, Snezana, et al.
(författare)
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Processes improving urban stormwater quality in grass swales and filter strips : A review of research findings
- 2019
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 669, s. 431-447
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Tidskriftsartikel (refereegranskat)abstract
- Increasing interest in urban drainage green infrastructure brings attention to grass swales and filter strips (GS&GFS) and their role in stormwater management. While the understanding of the hydrology and hydraulics of these stormwater control measures is adequate for current needs, there are knowledge gaps in understanding the water quality processes in GS&GFS and such a finding motivated preparation of the review paper that follows. The review revealed that most of the empirical studies of GS&GFS flow quality focused on the removal of pollutants associated with road runoff, and particularly solids, with relatively few studies addressing nutrients, traffic associated hydrocarbons, oxygen demanding substances, chloride, and faecal indicator bacteria. The reported results suffer from limitations caused by experimental conditions often representing a steady flow used to irrigate GS&GFS and generate runoff, non-submerged flows, no lateral inflows along swale side slopes, constant dosing of solids, emphasis on larger-than-typical solids, incomplete descriptions of experimental conditions, and limited attention to experimental uncertainties. Besides settling, other treatment processes, like adsorption/desorption, plant uptake, chemical precipitation and microbial degradation are often acknowledged, but without attempting to quantify their effects on flow quality. The modelling of GS&GFS flow quality would be beneficial for an improved understanding of green urban drainage infrastructure, but currently it is infeasible without a better knowledge of stormwater quality processes in GS&GFS facilities.
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| 8. |
- Lange, Katharina, et al.
(författare)
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Metal speciation in stormwater bioretention : Removal of particulate, colloidal and truly dissolved metals
- 2020
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 724
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Tidskriftsartikel (refereegranskat)abstract
- For comprehensive estimation of the metal treatment efficiency of bioretention systems, information on metal speciation in the stormwater and the effluent is needed. However, so far, most bioretention studies only considered total metal concentrations. Despite their environmental importance, dissolved metals (defined as fractions < 0.45 μm) have only been evaluated in few studies. This study represents the first bioretention study to subdivide the <0.45 μm fraction further by filtration through a 3 kDa ultrafilter (corresponding to appr. 2–3 nm), thus enabling distinction between particulate, colloidal and truly dissolved metals. Higher bioavailability of the truly dissolved fraction has been indicated by previous research, underlining the importance of this study. Since vegetation and salt in stormwater both may be explanatory variables for metal fractionation, these have been added as factors in the utilized full factorial pilot-scale column experiment. While total metal removal was often >95%, detailed fractionation revealed that Cu and (when no salt was added) Zn removal in the <0.45 μm and <3 kDa fractions was significantly lower. Further, mean concentrations of Cu and (in one treatment) Cd in the <0.45 μm effluent fraction did not meet Swedish receiving water quality guidelines. By calculating the particulate, colloidal and truly dissolved fractions, it was shown that bioretention systems affect metal speciation of Cu and Zn. Colloidal and truly dissolved fractions were mostly prevalent in the effluent rather than the influent. Salt affected metal removal mostly negatively. Fractionation was affected by salt mainly in the influent where it increased the concentrations of Cd and Zn in the truly dissolved fraction (no effects on Cu and Pb fractions). In the effluent, Cu and Zn were only slightly affected by salt. Vegetation had mostly no significant effects on metal removal and fractionation. Further integration of detailed metal fractionation into sampling routines in bioretention research is recommended.
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| 9. |
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| 10. |
- Lange, Katharina, et al.
(författare)
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Occurrence and concentration of 20–100 μm sized microplastic in highway runoff and its removal in a gross pollutant trap – Bioretention and sand filter stormwater treatment train
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 809
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Tidskriftsartikel (refereegranskat)abstract
- Microplastic pollution of stormwater can be a serious threat to the environment. Gross pollutant trap (GPT) - bioretention treatment trains have been shown previously to treat (inter alia) particulate stormwater pollutants including microplastic particles larger than 100 μm. This study was carried out to investigate whether such stormwater treatment trains also remove smaller 20 to 100 μm sized microplastic particles from highway runoff. Further, it investigates occurrence and concentration of 20 to 100 μm sized microplastic particles in highway runoff and which polymer types they can be assigned to. Volume proportional samples from nine rain events were taken from the incoming highway stormwater, from the gross pollutant trap effluent and the outflow from a bioretention system as well as a non-vegetated sand filter. The microplastic analyses were carried out using μFTIR and FTIR-ATR, which made it possible to detect particles where carbon black was present. It was found that 20 to 100 μm sized microplastic particles are abundant in highway runoff and that their concentrations are highly variable, with a median of 230 particles/L, a minimum of 42 particles/L and a maximum of 8577 particles/L. The dominant polymer types in highway stormwater were Polypropylene (PP), Ethylene Propylene Diene (EPDM) rubber and Ethylene-vinyl acetate (EVA). The treatment train with the bioretention system treated 20 to 200 μm sized microplastic particles significantly better than the treatment train with a non-vegetated sand filter, with median effluent concentrations of 26.5 particles/L and 121 particles/L, respectively. The GPT had no significant impact on the treatment of 20 to 100 μm sized microplastic particles.
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