| 1. |
- Edefell, Ellen, et al.
(författare)
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Digging deep into a GAC filter – Temporal and spatial profiling of adsorbed organic micropollutants
- 2022
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 218
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Tidskriftsartikel (refereegranskat)abstract
- A large pilot-scale granular activated carbon (GAC) filter was operated downstream in a full-scale wastewater treatment plant to remove organic micropollutants. To describe the spatial and temporal developments of micropollutant adsorption profiles in the GAC filter, micropollutants were extracted from GAC media taken at various filter depths and number of treated bed volumes. At a low number of treated bed volumes (2600 BVs), most micropollutants were adsorbed in the top layers of the filter. At increasing number of treated bed volumes (7300–15,500 BVs), the adsorption front for micropollutants progressed through the filter bed at varying rates, with sulfamethoxazole, fluconazole, and PFOS reaching the bottom layer before carbamazepine and other well-adsorbing micropollutants, such as propranolol and citalopram. Higher amounts of adsorbed micropollutants in the bottom layer of the filter bed resulted in decreased removal efficiencies in the treated wastewater. Mass estimations indicated biodegradation for certain micropollutants, such as naproxen, diclofenac, and sulfamethoxazole. A temporary increase in the concentration of the insecticide imidacloprid could be detected in the filter indicating that extraction of adsorbed micropollutants could provide an opportunity for backtracking of loading patterns.
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| 2. |
- Kharel, Suman, et al.
(författare)
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Ozone dose dependent formation and removal of ozonation products of pharmaceuticals in pilot and full-scale municipal wastewater treatment plants
- 2020
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697. ; 731
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Tidskriftsartikel (refereegranskat)abstract
- The removal of micropollutants from municipal wastewater is challenged by the number of compounds with diverse physico-chemical properties. Ozonation is increasingly used to remove micropollutants from wastewater. However, ozonation does not necessarily result in complete mineralization of the organic micropollutants but rather transforms them into new compounds which could be persistent or have adverse environmental effects. To explore ozone dose dependency of the formation and successive removal of ozonation products, two pilot-scale and one full-scale ozonation plants were operated subsequent to a conventional activated sludge treatment. The results from these trials indicated that the concentrations of several N-oxides, such as Erythromycin N-oxide, Venlafaxine N-oxide and Tramadol N-oxide, increased up to an ozone dose of 0.56–0.61 mg O3/mg DOC while they decreased at elevated doses of 0.7–1.0 mg O3/mg DOC. Similar results were also obtained for two transformation products of Diclofenac (Diclofenac 2,5-quinone imine and 1-(2,6-dichlorophenyl)indolin-2,3-dione) and one transformation product of Carbamazepine (1-(2-benzoic acid)-(1H,3H)-quinazoline-2,4-dione), where the highest concentrations appeared around 0.27–0.31 mg O3/mg DOC. The formation maximum of a given compound occurred at a specific ozone dose that is characteristic for each compound, but seemed to be independent of the wastewater used for the experiments at the two pilots and the full-scale plant.
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| 3. |
- Kharel, Suman, et al.
(författare)
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Removal of pharmaceutical metabolites in wastewater ozonation including their fate in different post-treatments
- 2021
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697. ; 759
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Tidskriftsartikel (refereegranskat)abstract
- Advanced treatment technologies for the removal of pharmaceuticals and other organic micropollutants in WWTPs primarily target the removal of parent compounds. Nevertheless, the removal of metabolites originating from human- or microbial metabolism during biological treatment needs comparable consideration, as some of them might be present in high concentrations and contribute to toxicity. This study was conducted to elucidate the removal of human and microbial metabolites of pharmaceuticals as a function of the specific ozone dose. Ozonation was performed on four sites with two pilot- and two full-scale plants operated downstream of conventional activated sludge plants. The ozone reactivity of all metabolites (expressed as the ozone dose to remove 90% of the compound/decadic ozone dose) was lower than those of their parent compounds. The decadic ozone dose was 1.0, 1.3 and 1.1 mg O3/mg DOC for Epoxy-carbamazepine, Di-OH-carbamazepine and N-Desmethyl tramadol, respectively. 20–40% of the remaining metabolites were removed in a polishing sand/BAC-filter (biological activated carbon). Similar removal was observed for Epoxy-carbamazepine, Di-OH-carbamazepine and Hydroxy-diclofenac in a constructed wetland. However, the sand/anthracite filter had no effect. All four metabolites were removed in a GAC (granulated activated carbon) filter.
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| 4. |
- Betsholtz, Alexander, et al.
(författare)
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New Perspectives on the Interactions between Adsorption and Degradation of Organic Micropollutants in Granular Activated Carbon Filters
- 2024
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Ingår i: Environmental Science and Technology. - : American Chemical Society. - 0013-936X .- 1520-5851. ; 58:26
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Tidskriftsartikel (refereegranskat)abstract
- The removal of organic micropollutants in granular activated carbon (GAC) filters can be attributed to adsorption and biological degradation. These two processes can interact with each other or proceed independently. To illustrate the differences in their interaction, three 14C-labeled organic micropollutants with varying potentials for adsorption and biodegradation were selected to study their adsorption and biodegradation in columns with adsorbing (GAC) and non-adsorbing (sand) filter media. Using 14CO2 formation as a marker for biodegradation, we demonstrated that the biodegradation of poorly adsorbing N-nitrosodimethylamine (NDMA) was more sensitive to changes in the empty bed contact time (EBCT) compared with that of moderately adsorbing diclofenac. Further, diclofenac that had adsorbed under anoxic conditions could be degraded when molecular oxygen became available, and substantial biodegradation (≥60%) of diclofenac could be achieved with a 15 min EBCT in the GAC filter. These findings suggest that theretention of micropollutants in GAC filters, by prolonging the micropollutant residence time through adsorption, can enable longer time periods for degradations than what the hydraulic retention time would allow for. For the biologically recalcitrant compound carbamazepine, differences in breakthrough between the 14C-labeled and nonradiolabeled compounds revealed a substantial retention via successive adsorption-desorption, which could pose a potential challenge in the interpretation of GAC filter performance.
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| 5. |
- Betsholtz, Alexander, et al.
(författare)
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Ozonation of 14C-labeled micropollutants – mineralization of labeled moieties and adsorption of transformation products to activated carbon
- 2022
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 221
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Tidskriftsartikel (refereegranskat)abstract
- Ozonation transformation products (OTPs) are largely unknown compounds that are formed during the ozonation of micropollutants, and it is uncertain to which extent these compounds can be removed by subsequent adsorption to activated carbon. Thus, 14C-labeled micropollutants were ozonated to generate 14C-labeled OTPs, for which the adsorption of the sum of all 14C-labeled OTPs to activated carbon could be determined, based on the adsorption of the labeled carbon. Further, 14CO2 traps were used to examine the mineralization of 14C-labeled moieties during ozonation. 14CO2-formation revealed a partial mineralization of the 14C-labeled moieties in all compounds except for propyl-labeled bisphenol A and O-methyl-labeled naproxen. A similar degree of mineralization was noted for different compounds labeled at the same moiety, including the carboxylic carbon in diclofenac and ibuprofen (∼40% at 1 g O3/g DOC) and the aniline ring in sulfamethoxazole and sulfadiazine (∼30% at 1 g O3/g DOC). Aromatic ring cleavage was also confirmed for bisphenol A, sulfamethoxazole, and sulfadiazine through the formation of 14CO2. The adsorption experiments demonstrated increased adsorption of micropollutants to powdered activated carbon after ozonation, which was connected to a decreased adsorption of dissolved organic matter (DOM). Conversely, the OTPs showed a substantial and successive decline in adsorption at increased ozone doses for all compounds, likely due to decreased hydrophobicity and aromaticity of the OTPs. These findings indicate that adsorption to activated carbon alone is not a viable removal method for a wide range of ozonation transformation products.
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| 6. |
- Betsholtz, Alexander, et al.
(författare)
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Tracking 14C-labeled organic micropollutants to differentiate between adsorption and degradation in GAC and biofilm processes
- 2021
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Ingår i: Environmental Science and Technology. - : The American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 55:16, s. 11318-11327
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Tidskriftsartikel (refereegranskat)abstract
- Granular activated carbon (GAC) filters can be used to reduce emissions of organic micropollutants via municipal wastewater, but it is still uncertain to which extent biological degradation contributes to their removal in GAC filters. 14C-labeled organic micropollutants were therefore used to distinguish degradation from adsorption in a GAC-filter media with associated biofilm. The rates and extents of biological degradation and adsorption were investigated and compared with other biofilm systems, including a moving bed biofilm reactor (MBBR) and a sand filter, by monitoring 14C activities in the liquid and gas phases. The microbial cleavage of ibuprofen, naproxen, diclofenac, and mecoprop was confirmed for all biofilms, based on the formation of 14CO2, whereas the degradation of 14C-labeled moieties of sulfamethoxazole and carbamazepine was undetected. Higher degradation rates for diclofenac were observed for the GAC-filter media than for the other biofilms. Degradation of previously adsorbed diclofenac onto GAC could be confirmed by the anaerobic adsorption and subsequent aerobic degradation by the GAC-bound biofilm. This study demonstrates the potential use of 14C-labeled micropollutants to study interactions and determine the relative contributions of adsorption and degradation in GAC-based treatment systems.
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| 7. |
- Betsholtz, Alexander, et al.
(författare)
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Tracking 14C-Labeled Organic Micropollutants to Differentiate between Adsorption and Degradation in GAC and Biofilm Processes
- 2021
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 55:16, s. 11318-11327
-
Tidskriftsartikel (refereegranskat)abstract
- Granular activated carbon (GAC) filters can be used to reduce emissions of organic micropollutants via municipal wastewater, but it is still uncertain to which extent biological degradation contributes to their removal in GAC filters. 14C-labeled organic micropollutants were therefore used to distinguish degradation from adsorption in a GAC-filter media with associated biofilm. The rates and extents of biological degradation and adsorption were investigated and compared with other biofilm systems, including a moving bed biofilm reactor (MBBR) and a sand filter, by monitoring 14C activities in the liquid and gas phases. The microbial cleavage of ibuprofen, naproxen, diclofenac, and mecoprop was confirmed for all biofilms, based on the formation of 14CO2, whereas the degradation of 14C-labeled moieties of sulfamethoxazole and carbamazepine was undetected. Higher degradation rates for diclofenac were observed for the GAC-filter media than for the other biofilms. Degradation of previously adsorbed diclofenac onto GAC could be confirmed by the anaerobic adsorption and subsequent aerobic degradation by the GAC-bound biofilm. This study demonstrates the potential use of 14C-labeled micropollutants to study interactions and determine the relative contributions of adsorption and degradation in GAC-based treatment systems.
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| 8. |
- Björklund, Erland, et al.
(författare)
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Utsläpp av 33 antibiotika, läkemedel och andra mikroföroreningar från Skånes Universitetssjukhus (SUS) i Malmö till Sjölunda avloppsreningsverk
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Under februari 2019 togs 7 dygnsprover på det totala utgående flödet av avloppsvatten från Skånes Universitetssjukhus (SUS) i Malmö samt på det totala inkommande flödet av avlopssvatten till Sjölunda avloppsreningsverk i Malmö, som är Malmös största reningsverk. Syftet var att få kunskap om utgående koncentrationer av läkemedel från sjukhuset i relation till de inkommande koncentrationerna till avloppsreningsverket. Proverna togs från måndag till söndag under en och samma vecka och analyserades med avseende på förekomst av 33 läkemedel, antibiotika och andra mikroföroreningar. Detta innefattade 9 st antibiotika, 19 st läkemedel samt 5 andra kemikalier.
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| 9. |
- Björklund, Erland, et al.
(författare)
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Utsläpp av 33 antibiotika, läkemedel och andra mikroföroreningar från Skånes Universitetssjukhus (SUS) i Malmö till Sjölunda avloppsreningsverk
- 2020
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Under februari 2019 togs 7 dygnsprover på det totala utgående flödet av avloppsvatten från Skånes Universitetssjukhus (SUS) i Malmö samt på det totala inkommande flödet av avlopssvatten till Sjölunda avloppsreningsverk i Malmö, som är Malmös största reningsverk. Syftet var att få kunskap om utgående koncentrationer av läkemedel från sjukhuset i relation till de inkommande koncentrationerna till avloppsreningsverket. Proverna togs från måndag till söndag under en och samma vecka och analyserades med avseende på förekomst av 33 läkemedel, antibiotika och andra mikroföroreningar. Detta innefattade 9 st antibiotika, 19 st läkemedel samt 5 andra kemikalier.
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| 10. |
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