| 1. |
- Gidstedt, Simon, et al.
(författare)
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Chemically enhanced primary treatment, microsieving, direct membrane filtration and GAC filtration of municipal wastewater : a pilot-scale study
- 2022
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Ingår i: Environmental Technology (United Kingdom). - : Taylor and Francis Ltd.. - 0959-3330 .- 1479-487X. ; , s. 12
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Tidskriftsartikel (refereegranskat)abstract
- Chemically enhanced primary treatment (CEPT) followed by microsieving and direct membrane filtration (DMF) as ultrafiltration, was evaluated on pilot scale at a municipal wastewater treatment plant. In addition, a granular activated carbon (GAC) filter downstream of DMF was evaluated for the removal of organic micropollutants. Up to 80% of the total organic carbon (TOC) and 96% of the total phosphorus were removed by CEPT with microsieving. The additional contribution of subsequent DMF was minor, and only five days of downstream GAC filtration was possible due to fouling of the membrane. Of the 21 organic micropollutants analysed, all were removed (≥ 98%) by the GAC filter until 440 bed volumes, while CEPT with microsieving and DMF removed only a few compounds. Measurements of the oxygen uptake rate indicated that the required aeration for supplementary biological treatment downstream of CEPT with microsieving, both with and without subsequent DMF, was 20−25% of that in the influent wastewater. This study demonstrated the potential of using compact physicochemical processes to treat municipal wastewater, including the removal of organic micropollutants.
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| 2. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
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Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 3. |
- Takman, Maria, et al.
(författare)
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Assessing the potential of a membrane bioreactor and granular activated carbon process for wastewater reuse – A full-scale WWTP operated over one year in Scania, Sweden
- 2023
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 895
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Tidskriftsartikel (refereegranskat)abstract
- A full-scale membrane bioreactor (MBR) with ultrafiltration, followed by granular activated carbon (GAC), was examined to determine the potential of reusing treated water as a source of drinking water or for irrigation. The major part of the bacteria removal took place in the MBR, whereas the GAC removed substantial amounts of organic micropollutants. Annual variations in inflow and infiltration resulted in a concentrated influent during summer and a diluted influent in the winter. The removal of E. coli was high throughout the process (average log removal 5.8), with effluent concentrations meeting the threshold for class B water standards for irrigation (EU 2020/741) but exceeding those for drinking water in Sweden. The total bacterial concentration increased over the GAC, indicating the growth and release of bacteria; however, E. coli concentrations declined. The effluent concentrations of metals met the Swedish criteria for drinking water. The removal of organic micropollutants decreased during the initial operation of the treatment plant, but after 1 year and 3 months, corresponding to 15,000 bed volumes, the removal increased. Maturation of the biofilm in the GAC filters might have resulted in biodegradation of certain organic micropollutants, in combination with bioregeneration. Although there is no legislation in Scandinavia with regard to many organic micropollutants in drinking water and water for irrigation, the effluent concentrations were generally in the same order of magnitude as to those in Swedish source waters that are used for drinking water production.
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| 4. |
- Takman, Maria, et al.
(författare)
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Biological degradation of organic micropollutants in GAC filters–temporal development and spatial variations
- 2024
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Ingår i: Journal of Hazardous Materials. - : Elsevier. - 0304-3894. ; 472
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Tidskriftsartikel (refereegranskat)abstract
- The capacity for organic micropollutant removal in granular activated carbon (GAC) filters for wastewater treatment changes over time. These changes are in general attributed to changes in adsorption, but may in some cases also be affected by biological degradation. Knowledge on the degradation of organic micropollutants, however, is scarce. In this work, the degradation of micropollutants in several full-scale GAC and sand filters was investigated through incubation experiments over a period of three years, using 14C-labeled organic micropollutants with different susceptibilities to biological degradation (ibuprofen, diclofenac, and carbamazepine), with parallel 16S rRNA gene sequencing. The results showed that the degradation of diclofenac and ibuprofen in GAC filters increased with increasing numbers of bed volumes when free oxygen was available in the filter, while variations over filter depth were limited. Despite relatively large differences in bacterial composition between filters, a degradation of diclofenac was consistently observed for the GAC filters that had been operated with high influent oxygen concentration (DO >8 mg/L). The results of this comprehensive experimental work provide an increased understanding of the interactions between microbial composition, filter material, and oxygen availability in the biological degradation of organic micropollutants in GAC filters.
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| 5. |
- Takman, Maria
(författare)
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From removal of organic micropollutants to municipal wastewater reuse - technological and social perspectives
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, wastewater reuse was investigated from technological and social perspectives, based onwhich the thesis was divided into two parts. In the first part, the removal of chemical and microbialcontaminants by full-scale and pilot-scale granular activated carbon (GAC) filters, in different processcombinations, was examined. In the second part, the perceptions of reused wastewater were studiedthrough a discourse analysis and compared with those of desalinated seawater, which is anotheralternative water source.The results showed that the treatment of wastewater with a process combination of a membranebioreactor, GAC filtration, and disinfection with ultraviolet radiation improved its quality to a level thatapproached that of drinking water. Limits on some organic micropollutants, such as pharmaceuticals, aregenerally not included in drinking water legislation or legislation for irrigation with reused wastewater,adding insecurities to the evaluation of water quality. Nevertheless, the water was treated to a highdegree and potentially constitutes a beneficial supplementary resource for irrigation or drinking waterproduction during drought or times of water scarcity. Whether the water criteria need to be complementedwith additional parameters merits further investigation.Organic micropollutants are removed by GAC filters primarily through adsorption but also throughbiological degradation. Measurements from a full-scale GAC filter indicated degradation of certainpharmaceuticals, which was confirmed in laboratory experiments with granules from various GAC filters.The degradation appeared to be affected specifically by the oxygen concentration in the filters and byoperation time.In the second part of the thesis work, the discourses over wastewater reuse and desalination on theSwedish islands of Öland and Gotland were examined and compared with general discourses identifiedfrom literature. Wastewater reuse and desalination are ways of producing drinking water whengroundwater and surface water resources are not sufficient and are often compared in the literature. Theresults showed that the local discourses often had similarities with the general ones and that there weredifferences between the two islands. Desalination on Gotland seemed to be more controversial thanwastewater reuse and desalination on Öland, and the perceptions of wastewater reuse and desalinationwere affected by many factors, such as visions and values with regard to welfare or sustainability andother political topics—for example local industries.
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| 6. |
- Takman, Maria, et al.
(författare)
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Storylines and Imaginaries of Wastewater Reuse and Desalination: The Rise of Local Discourses on the Swedish Islands of Öland and Gotland
- 2023
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Ingår i: Water Alternatives. - 1965-0175. ; 16:1, s. 207-243
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Tidskriftsartikel (refereegranskat)abstract
- Increased pressure on existing freshwater resources has given rise to interest in new raw water sources. Wastewater reuse and desalination are two alternatives that are frequently compared and discussed in the literature. In this study, local discourses in the form of storylines and imaginaries were identified on the Swedish islands of Öland and Gotland. These local storylines and imaginaries were then compared to those found in the literature on wastewater reuse and desalination; in the process, overlaps and variations were identified. On Gotland, a controversy over desalination was observed where arguments were raised for and against 'natural' (nature-based and therefore 'good') solutions and 'unnatural' or engineered solutions (desalination). Such a controversy was not observed on Öland. The controversy on Gotland arose out of competing imaginaries of the future. Such discourses can affect the transitions of water systems. Understanding local discourses may thus be crucial to our understanding of the larger transitions underway in the water sector and may figure importantly in the acceptance of new water sources.
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| 7. |
- Takman, Maria, et al.
(författare)
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Återanvändning av renat avloppsvatten : Potential efter rening med en membranbioreaktor följt av granulerat aktivt kol
- 2022
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Rapport (populärvet., debatt m.m.)abstract
- The treated wastewater from a full scale MBR and GAC reached drinking water quality regarding metals, but not bacteria. The water quality is however assessed as sufficient for irrigation or as a source water for drinking water production, based on the parameters analyzed in the project. The concentrations of organic micro pollutants were similar to the ones measured in Swedish drinking water sources, and hence similar to concentrations that we accept in the water we use for drinking water production.
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