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- Milovanovic, Ivan, 1990-
(author)
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Components for area-efficient stormwater treatment systems
- 2021
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Licentiate thesis (other academic/artistic)abstract
- With progressing urbanisation, treatment of urban stormwater is a vital issue that should be addressed to ensure good water quality in receiving water bodies. Treatment may be performed near the source, with different filter systems using various filter materials, or by using an end-of-pipe method, e.g. a stormwater pond. One constraint in the urban environment is the lack of available space in developed areas, where stormwater treatment facilities are needed the most. Methods developed to treat the stormwater runoff have been the focus of previous studies but the increasing standards of water quality and increasing land constraint pressures demand the further development of stormwater treatment systems. Both laboratory and field experiments are necessary to understand and improve the treatment processes as well as to evaluate how the implemented methods perform under field conditions. The aim of the thesis was to increase the knowledge about the components in stormwater treatment systems that can be used in area-efficient treatment facilities. In order to compare four potential stormwater filter materials (peat, bark, air-blown polypropylene and milkweed), column experiments were carried out using synthetic stormwater that simulated road runoff. Experiments were carried out to evaluate the impacts of the ageing of synthetic stormwater quality during laboratory testing, including dissolved metal concentrations and their impact on the estimation of filter efficiency. In a field study, a full-scale application of a zeolite filter installation was investigated, with a focus on service life and the efficiency of treating copper roof runoff. In order to further investigate a novel sedimentation device, a bottom grid structure (BGS), promoting sediment settling in a smaller area of a stormwater pond, a hydraulic modelling study was conducted to investigate the impact of the cell geometry of the structure on sediment settling and the impact of the structure on pond maintenance and sediment resuspension. The column tests of four different filter materials showed that bark and peat had higher treatment efficiency for dissolved metals than milkweed and polypropylene, with the order of efficiency being peat>bark>milkweed>polypropylene. All four of the filter materials showed a total metal reduction of over 70%, which could be due to the separation of particle-bound metals in the columns. The ageing of the synthetic stormwater showed that dissolved metals, particularly copper, decreased in concentration, quite rapidly. During one experiment run, the dissolved copper concentration was reduced to 15% of its initial value. In order to account for the concentration changes an equation was proposed that normalised the concentration of dissolved metal over the duration of the experiment. During the observation period of 16 months, the zeolite installation removed 52% to 82% and 48% to 94% of total and dissolved copper, respectively. However, the effluent concentrations were still high (360-600 μg/l). There was also an indication of the decreasing filter performance over time with a prediction that the treatment level of total copper would drop to approximately 25% by the end of the service life of three years. The hydraulic experiments on a scaled model of a BGS showed that wider cells were on average 13% more efficient in trapping the particles than the narrower variant. The cell wall angle also had an impact (tilted walls added to the sedimentation efficiency), although the applicability of such cell structures can be questioned, as this cell shape may hinder maintenance efforts. It was also hypothesised that the inclusion of the BGS in the pond reduces the area needed for sediment settling, thus making the pond more area-efficient and easier to include in an urbanised setting.
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| 2. |
- Milovanovic, Ivan, 1990-, et al.
(author)
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Enhancing stormwater sediment settling at detention pond inlets by a Bottom Grid Structure
- 2019
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Conference paper (peer-reviewed)abstract
- Stormwater sediments of various sizes and densities are recognised as one of the most important stormwater quality parameters that can be conventionally controlled by settling in detention ponds. The Bottom Grid Structure (BGS) is an innovative (non-proprietary) concept proposed in this study to enhance removal of stormwater sediments entering ponds and reduce sediment resuspension. This concept was studied in a hydraulic scale model with the objective of elucidating the effects of the BGS geometry on stormwater sediment trapping. Towards this end, the BGS cell size and depth, and the cell cross-wall angle were varied for a range of flow rates, and the sediment trapping efficiency was measured in the model. The main value of the observed sediment trapping efficiencies, in the range from 13 to 55%, was a comparative assessment of various BGS designs. In general, larger cells (footprint 10x10 cm, in the model) were more effective than the smaller cells (5x5 cm), the cell depth exerted small influence on sediment trapping, and the cells with inclined cross-walls proved more effective in sediment trapping than the vertical cross-walls. However, the BGS with inclined cross-walls would be harder to maintain. Future studies should address an optimal cell design and testing in an actual stormwater pond.
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| 3. |
- Milovanovic, Ivan, 1990-, et al.
(author)
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Enhancing stormwater sediment settling at detention pond inlets by a bottom grid structure (BGS)
- 2020
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In: Water Science and Technology. - London, UK : IWA Publishing. - 0273-1223 .- 1996-9732. ; 81:2, s. 274-282
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Journal article (peer-reviewed)abstract
- Stormwater sediments of various sizes and densities are recognised as one of the most important stormwater quality parameters that can be conventionally controlled by settling in detention ponds. The bottom grid structure (BGS) is an innovative concept proposed in this study to enhance removal of stormwater sediments entering ponds and reduce sediment resuspension. This concept was studied in a hydraulic scale model with the objective of elucidating the effects of the BGS geometry on stormwater sediment trapping. Towards this end, the BGS cell size and depth, and the cell cross-wall angle were varied for a range of flow rates, and the sediment trapping efficiency was measured in the model. The main value of the observed sediment trapping efficiencies, in the range from 13 to 55%, was a comparative assessment of various BGS designs. In general, larger cells (footprint 10 × 10 cm) were more effective than the smaller cells (5 × 5 cm), the cell depth exerted small influence on sediment trapping, and the cells with inclined cross-walls proved more effective in sediment trapping than the vertical cross-walls. However, the BGS with inclined cross-walls would be harder to maintain. Future studies should address an optimal cell design and testing in an actual stormwater pond.
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| 4. |
- Milovanovic, Ivan, 1990-, et al.
(author)
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Performance of a Zeolite Filter treating Copper Roof Runoff
- 2022
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In: Urban Water Journal. - : Taylor & Francis. - 1573-062X .- 1744-9006. ; 19:5, s. 499-508
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Journal article (peer-reviewed)abstract
- Copper is a common roofing material used in urban environments, yet it poses a threat to the ecosystem. Space requirements for stormwater treatment in urban areas are often problematic. This study investigated the treatment efficiency of a filter system containing zeolite as filter medium and treatment of copper roof runoff in field conditions. Emphasis was placed on copper and zinc treatment, while the release of sodium and aluminium was also evaluated. The filter system was monitored over a period of 16 months (7 sampling events). The filter reduced the total and dissolved copper by 52–82% and 48–85%, respectively. Although the average observed treatment efficiency of copper and zinc was high, considerable decline in filter efficiency was noticed, indicating potential saturation of the filter medium. Moreover, the copper concentrations in the outlet were still high, 350–600 μg/l, and significantly higher than the concentrations recommended by the relevant authorities.
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| 5. |
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| 6. |
- Milovanovic, Ivan, 1990-, et al.
(author)
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Synthetic stormwater for laboratory testing of filter materials
- 2023
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In: Environmental technology. - : Taylor & Francis. - 0959-3330 .- 1479-487X. ; 44:11, s. 1600-1612
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Journal article (peer-reviewed)abstract
- Synthetic stormwater was tested to determine the ageing effects on dissolved metal concentrations and used in a column experiment to determine efficiency of four different filter materials (milkweed, bark, peat, polypropylene) in removing total and dissolved metals. Synthetic stormwater was created by adding metal salts, oil and collected stormwater sediment to tap water. Two ageing experiments were performed to determine the change of synthetic stormwater quality over time. One experiment lasted for 11 days and another focused on rapid concentration changes one day after preparation. The one-day ageing experiment showed rapid decrease in dissolved concentration of certain metals, specifically Cu. To consider this change, correction coefficients for each metal were developed and used to estimate the average dissolved metal concentration in the synthetic stormwater during the experiment to determine filter treatment efficiency. During the 11-day experiment on metal concentrations, no noticeable quality changes were observed for at least six days after the preparation of synthetic stormwater. Furthermore, a column experiment was run with duplicate filter columns. Inflow and outflow samples were analysed for total and dissolved metals, turbidity, particle size distribution, and pH. High removal of total metal concentrations was noticed in all tested filter media (58-94%). Dissolved metal concentration removal varied among different filter media. In general, columns with bark and peat media were able to treat dissolved metals better than polypropylene and milkweed. The level of treatment of dissolved metals between the different filter media columns were bark > peat > milkweed > polypropylene.
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| 7. |
- Milovanovic, Ivan, 1990-, et al.
(author)
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Zeolitfilter för avrinning från koppartak
- 2024
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Other publication (other academic/artistic)abstract
- Koppar används ibland som takmaterial i städer, men det medför problem för miljön. Avrinningen från koppartak är svår att behandla i stadsmiljöer. En ny studie har tittat på hur effektivt ett filtersystem med zeolit som filtermedium kan vara för att minska kopparhalten. Resultaten visar att filtret lyckades minska total och löst koppar med 52–82 % respektive 48–85 %. Trots detta var kopparhalterna i avrinningen fortfarande höga, mellan 350–600 μg/l. Detta överstiger rekommenderade nivåer och indikerar behovet av fortsatt forskning för att förbättra behandlingsmetoderna och minimera miljöpåverkan från koppartak.
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