Removal of Metals from Stormwater in Rain Gardens with Different Sorption Materials
| dc.contributor.author | JARDEBY, ANDERS | |
| dc.contributor.department | Chalmers tekniska högskola / Institutionen för arkitektur och samhällsbyggnadsteknik (ACE) | sv |
| dc.contributor.department | Chalmers tekniska högskola / Institutionen för arkitektur och samhällsbyggnadsteknik (ACE) | en |
| dc.contributor.examiner | Hvitt Strömvall, Ann-Margret | |
| dc.date.accessioned | 2023-09-14T11:02:56Z | |
| dc.date.available | 2023-09-14T11:02:56Z | |
| dc.date.issued | 2023 | |
| dc.date.submitted | 2023 | |
| dc.description.abstract | Polluted stormwater is a common problem in urban environments. With large parts of cities made up of impermeable areas and an expected increase of heavy rain, this is an issue that likely will get more attention in the coming years. In order to relieve pollution effects on the aquatic ecosystems’ stormwater treatment alternatives must be developed. One possible treatment system is rain gardens, where polluted stormwater can be treated by both infiltration and retention techniques. This project was carried through at a pilot rain garden located in Gårda where stormwater from the catchment is treated in bioretention filters with different sorption materials such as ash, biochar, peat, and a control filter with compost. Three types of sampling were done, one after that different amounts of water volumes were added and then the effluents were sampled, the second at different depths in the filter beds through soil-water samplers under vacuum, and the third through passive sampling from a pipe inserted in the filter bed at the corresponding depths as the soil-water samplers. Sampling was carried out during winter conditions when the plants in filter beds were believed to be inactive. Three sampling occasions were done of treated stormwater per sampling method and the untreated stormwater, i.e., the influent The concentrations of eight metals, As, Pb, Cd, Co, Cu, Cr, Ni, and Zn, both dissolved and total metal concentrations, were analysed in all samples and additional analysis of TSS, VSS, IC, TOC, and TN were conducted in the laboratory. The results showed high removal capacities of the metals mostly occurring in high concentrations in urban stormwater such as Co, Cu, Ni, and total Pb and Cu. Arsenic in general and dissolved Pb, Cd, and Cr were not effectively removed, instead, these metals leached from all filters. Three metals, Cu, Cr, and Zn had concentrations exceeding the guideline values of the Gothenburg municipality for discharge of polluted water to recipients from all filters. The removal efficiency of total suspended solids (TSS) and volatile suspended solids (VSS) was high in all filters whereas the removal efficiency of cations, anions, dissolved organic carbon (DOC), and dissolved total nitrogen (TN) varied among the different filters. Of the four filters studied, biochar was the most efficient for the removal of metals and organic matter, and the remaining three filters performed quite similarly. The conclusion of this thesis work is that biochar filters are recommended for the removal of TSS, VSS, and metals emitted in urban environments. Further research is recommended to clarify why some metals,such as Asleach from the soil and sorption materials. The results for the removal efficiency of anions, cations DOC, and TN were inconclusive and further studies are recommended. | |
| dc.identifier.coursecode | ACEX30 | |
| dc.identifier.uri | http://hdl.handle.net/20.500.12380/307024 | |
| dc.language.iso | eng | |
| dc.setspec.uppsok | Technology | |
| dc.subject | Stormwater treatment, bioretention filters, toxic trace metals, winter conditions, biochar, peat and ash | |
| dc.title | Removal of Metals from Stormwater in Rain Gardens with Different Sorption Materials | |
| dc.type.degree | Examensarbete för masterexamen | sv |
| dc.type.degree | Master's Thesis | en |
| dc.type.uppsok | H | |
| local.programme | Infrastructure and environmental engineering (MPIEE), MSc |