| 1. |
- Betsholtz, Alexander, et al.
(author)
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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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In: Environmental Science and Technology. - : The American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 55:16, s. 11318-11327
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Journal article (peer-reviewed)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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| 2. |
- Gidstedt, Simon, et al.
(author)
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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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In: Environmental Technology (United Kingdom). - : Taylor and Francis Ltd.. - 0959-3330 .- 1479-487X. ; , s. 12
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Journal article (peer-reviewed)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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| 3. |
- Betsholtz, Alexander, et al.
(author)
-
Tracking 14C-Labeled Organic Micropollutants to Differentiate between Adsorption and Degradation in GAC and Biofilm Processes
- 2021
-
In: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 55:16, s. 11318-11327
-
Journal article (peer-reviewed)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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| 4. |
- Burzio, Cecilia, 1991, et al.
(author)
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Removal of organic micropollutants in the biological units of a Swedish wastewater treatment plant
- 2021
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In: IOP Conference Series: Materials Science and Engineering. - 1757-8981 .- 1757-899X. ; 1209
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Conference paper (peer-reviewed)abstract
- The present study investigates the presence and removal of target organic micropollutants in a large Swedish wastewater treatment plant designed for nutrient removal including activated sludge, trickling filters, nitrifying moving bed biofilm reactors (MBBRs) and post-denitrifying MBBRs. A total of 28 organic micropollutants were analysed, at concentrations ranging from few ng/L to µg/L, in the influent and effluent of the different biological reactors in two sampling campaigns. The observed micropollutant removal efficiencies of the wastewater treatment plant varied from insignificant (< 20%) to high (> 90%) between compounds. The activated sludge reactor, being the first in line, contributed to most of the removal from the water phase. Additional removal of a few compounds was observed in the biofilm units, but most of the persistent compounds remained stable through all biological treatments.
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| 5. |
- Gidstedt, Simon, et al.
(author)
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A comparison of adsorption of organic micropollutants onto activated carbon following chemically enhanced primary treatment with microsieving, direct membrane filtration and tertiary treatment of municipal wastewater
- 2022
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In: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 811:152225
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Journal article (peer-reviewed)abstract
- The adsorption of organic micropollutants onto powdered activated carbon (PAC) was investigated in laboratory scale based on samples from four wastewater process streams (matrices); three from a pilot-scale plant with different degrees of physicochemical treatment of municipal wastewater and one from a full-scale activated sludge plant with post-precipitation. The pilot-scale treatment consisted of chemically enhanced primary treatment with microsieving followed by direct membrane filtration as microfiltration or ultrafiltration. The results showed highest adsorption of micropollutants in the tertiary (biologically and chemically) treated wastewater and lowest adsorption in the microsieve filtrate. Adsorption of micropollutants in the direct membrane microfiltration (200 nm) permeate was generally similar to that in the direct membrane ultrafiltration (3 nm) permeate. The higher adsorption of micropollutants in the tertiary treated wastewater could be related to a lower concentration of dissolved organic carbon (DOC) and lower affinity of DOC for PAC at low dosage (<15 mg PAC/L) in this matrix. At a PAC dose of 10 mg/L, sulfamethoxazole was removed by 33% in the tertiary treated wastewater and 7% in the direct membrane microfiltration permeate. In addition to the PAC experiments, a pilot scale sand filter and a proceeding GAC filter was operated on tertiary treated wastewater from the full-scale treatment plant. Similar removal trends in the PAC and GAC experiments were observed when studying a weighted average micropollutant removal in the GAC filter and a similar dose of activated carbon for both PAC and GAC. Positively charged micropollutants were removed to a higher extent than negatively charged ones by both PAC and GAC.
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| 6. |
- Takman, Maria, et al.
(author)
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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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In: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 895
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Journal article (peer-reviewed)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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| 7. |
- Björklund, Erland, et al.
(author)
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Pharmaceutical residues affecting the UNESCO biosphere reserve Kristianstads Vattenrike wetlands : sources and sinks
- 2016
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In: Archives of Environmental Contamination and Toxicology. - 0090-4341 .- 1432-0703. ; 71:3, s. 423-436
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Journal article (peer-reviewed)abstract
- This study is the first to investigate the pharmaceutical burden from point sources affecting the UNESCO Biosphere Reserve Kristianstads Vattenrike, Sweden. The investigated Biosphere Reserve is a >1000 km(2) wetland system with inflows from lakes, rivers, leachate from landfill, and wastewater-treatment plants (WWTPs). We analysed influent and treated wastewater, leachate water, lake, river, and wetland water alongside sediment for six model pharmaceuticals. The two WWTPs investigated released pharmaceutical residues at levels close to those previously observed in Swedish monitoring exercises. Compound-dependent WWTP removal efficiencies ranging from 12 to 100 % for bendroflumethiazide, oxazepam, atenolol, carbamazepine, and diclofenac were observed. Surface-water concentrations in the most affected lake were ≥100 ng/L for the various pharmaceuticals with atenolol showing the highest levels (>300 ng/L). A small risk assessment showed that adverse single-substance toxicity on aquatic organisms within the UNESCO Biosphere Reserve is unlikely. However, the effects of combinations of a large number of known and unknown pharmaceuticals, metals, and nutrients are still unknown.
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| 8. |
- Burzio, Cecilia, 1991, et al.
(author)
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Removal of organic micropollutants from municipal wastewater by aerobic granular sludge and conventional activated sludge
- 2022
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In: Journal of Hazardous Materials. - : Elsevier BV. - 1873-3336 .- 0304-3894. ; 438
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Journal article (peer-reviewed)abstract
- Removal performances of organic micropollutants by conventional activated sludge (CAS) and aerobic granular sludge (AGS) were investigated at a full-scale wastewater treatment plant. Lab-scale kinetic experiments were performed to assess the micropollutant transformation rates under oxic and anoxic conditions. Transformation rates were used to model the micropollutant removal in the full-scale processes. Metagenomic sequencing was used to compare the microbial communities and antimicrobial resistance genes of the CAS and AGS systems. Higher transformation ability was observed for CAS compared to AGS for most compounds, both at the full-scale plant and in the complementary batch experiments. Oxic conditions supported the transformation of several micropollutants with faster and/or comparable rates compared to anoxic conditions. The estimated transformation rates from batch experiments adequately predicted the removal for most micropollutants in the full-scale processes. While the compositions in microbial communities differed between AGS and CAS, the full-scale biological reactors shared similar resistome profiles. Even though granular biomass showed lower potential for micropollutant transformation, AGS systems had somewhat higher gene cluster diversity compared to CAS, which could be related to a higher functional diversity. Micropollutant exposure to biomass or mass transfer limitations, therefore played more important roles in the observed differences in OMP removal.
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| 9. |
- Burzio, Cecilia, 1991, et al.
(author)
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Sorption of pharmaceuticals to foam and aerobic granular sludge with different morphologies
- 2024
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In: Resources, Environment and Sustainability. - : Elsevier BV. - 2666-9161. ; 15
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Journal article (peer-reviewed)abstract
- In biological wastewater treatment, the sorption process is an important removal pathway of organic micropollutants from the aqueous phase. Beyond the conventional sorption to biomass and particulate matter, organic molecules can also partition to gas bubbles commonly present in aerated biological processes. This study investigated the partitioning behavior of 21 selected pharmaceuticals to two types of aerobic granular sludge, and the foam generated by aeration. Batch sorption experiments were performed with biologically inactive granules of controlled diameters (0.5–1, 1–2, and >2 mm). Removal during sorption tests was observed for four positively charged micropollutants (sertraline, citalopram, clarithromycin, and erythromycin), four neutral compounds (levonorgestrel, estradiol, ethinylestradiol, and ketoconazole), and one negatively charged pharmaceutical (losartan). This highlights the importance of electrostatic interactions and lipophilic affinity with the solids. For some compounds, the removal increased with time, suggesting that sorption in thick biofilm is limited by molecular diffusion into the biofilm matrix. Furthermore, partitioning of pharmaceuticals to aeration-induced foam was confirmed in separate batch tests. Clarithromycin, erythromycin, ketoconazole, losartan, levonorgestrel, and ethinylestradiol exhibited concentrations in the foam 1.0–5.3 times higher than the initial test values, indicating potential adsorption at the liquid/gas interface for these compounds.
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| 10. |
- Kårelid, Victor, 1989-
(author)
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Towards application of activated carbon treatment for pharmaceutical removal in municipal wastewater
- 2016
-
Licentiate thesis (other academic/artistic)abstract
- Many pharmaceuticals are found in municipal wastewater effluents due to their persistence in the human body as well as in conventional wastewater treatment processes. This discharge to the environment can lead to adverse effects in aquatic species, such as feminization of male fish. During the past decade, these findings have spawned investigations and research into suitable treatment technologies that could severely limit the discharge. Adsorption onto activated carbon has been identified as one of the two main technologies for implementation of (future) full-scale treatment.Recent research has put a closer focus on adsorption with powdered activated carbon (PAC) than on granular activated carbon (GAC). Studies where both methods are compared in parallel operation are thus still scarce and such evaluation in pilot-scale was therefore a primary objective of this thesis. Furthermore, recirculation of PAC can be used to optimize the treatment regarding the carbon consumption. Such a setup was evaluated as a separate treatment stage to comply with Swedish wastewater convention. Additionally, variation of a set of process parameters was evaluated.During successive operation at three different wastewater treatment plants an overall pharmaceutical removal of 95% could consistently be achieved with both methods. Furthermore, treatment with GAC was sensitive to a degraded effluent quality, which severely reduced the hydraulic capacity. Both treatment methods showed efficient removal of previously highlighted substances, such as carbamazepine and diclofenac, however in general a lower adsorption capacity was observed for GAC. By varying the input of process parameters, such as the continuously added dose or the contact time, during PAC treatment, a responsive change of the pharmaceutical removal could be achieved. The work in this thesis contributes some valuable field experience towards wider application of these treatment technologies in full-scale.
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