| 1. |
- Andersson, Agneta, et al.
(author)
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Metabarcoding vs Microscopy - comparison of methods to monitor phytoplankton communities
- 2023
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In: ACS - ES & T Water. - : American Chemical Society (ACS). - 2690-0637. ; 3:8, s. 2671-2680
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Journal article (other academic/artistic)abstract
- Phytoplankton are used worldwide to monitor environmental status in aquatic systems. Long-time series of microscopy-analyzed phytoplankton are available from many monitoring stations. The microscopy-method is however time consuming and has short-comings. DNA metabarcoding has been suggested as an alternative method, but the consistency between different methods need further investigation. We performed a comparative study of microscopy and metabarcoding analyzing micro- and nanophytoplankton. For metabarcoding, 25-1000 ml seawater were filtered, DNA extracted and the 18S and 16S rRNA gene amplicons sequenced. For microscopy, based on the Utermöhl method we evaluated the use of three metrics: abundance, biovolume and carbon biomass. At the genus, species, and unidentified taxa level, metabarcoding generally showed higher taxonomic diversity than microscopy, and diversity was already captured at the lowest filtration volume tested, 25 ml. Metabarcoding and microscopy displayed relatively similar distribution pattern at the group level. The results showed that the relative abundances of the 18S rRNA amplicon at the group level best fitted the microscopy carbon biomass metric. The results are promising for implementing DNA metabarcoding as a complement to microscopy in phytoplankton monitoring, especially if databases would be improved and group level indexes could be applied to classify the environmental state of water bodies.
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| 2. |
- Aro, Rudolf, 1992-, et al.
(author)
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Fluorine Mass Balance Analysis of Effluent and Sludge from Nordic Countries
- 2021
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In: ACS - ES & T Water. - : American Chemical Society (ACS). - 2690-0637. ; 1:9, s. 2087-2096
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Journal article (peer-reviewed)abstract
- Recent publications have highlighted the ubiquitous presence of unidentified organofluorine compounds, whose environmental occurrence is poorly understood. In this study, wastewater treatment plant (WWTP) effluent and sludge samples from seven countries were analyzed for extractable organofluorine (EOF) and target PFAS, to evaluate which compounds are released back into the environment. Fluorine mass balance analysis of effluent samples (n = 14) revealed that on average 90% of the EOF could not be explained by the 73 PFAS monitored in this investigation. The levels of EOF in effluent (324–1460 ng of F/L) and sludge (39–210 ng of F/g of dry weight) indicate that a substantial amount of organofluorine compounds is released back into nature. A commonly overlooked PFAS class, ultra-short-chain PFCAs, accounted for 4% of EOF on average, while the remaining 71 compounds explained only a further 6% of EOF on average. The highest number of PFAS was detected in the effluent dissolved phase (37), compared to 29 and 23 PFAS in sludge and effluent particulate phase, respectively. The increased concentrations of EOF in both WWTP effluent and sludge are of concern, as the chemical species contained therein remain largely unknown, and thus, their potential health and environmental risks cannot be assessed.
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| 3. |
- Fenner, Kathrin, et al.
(author)
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Methodological Advances to Study Contaminant Biotransformation : New Prospects for Understanding and Reducing Environmental Persistence?
- 2021
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In: ACS - ES & T Water. - : American Chemical Society (ACS). - 2690-0637. ; 1:7, s. 1541-1554
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Journal article (peer-reviewed)abstract
- Complex microbial communities in environmental systems play a key role in the detoxification of chemical contaminants by transforming them into less active metabolites or by complete mineralization. Biotransformation, i.e., transformation by microbes, is well understood for a number of priority pollutants, but a similar level of understanding is lacking for many emerging contaminants encountered at low concentrations and in complex mixtures across natural and engineered systems. Any advanced approaches aiming to reduce environmental exposure to such contaminants (e.g., novel engineered biological water treatment systems, design of readily degradable chemicals, or improved regulatory assessment strategies to determine contaminant persistence a priori) will depend on understanding the causal links among contaminant removal, the key driving agents of biotransformation at low concentrations (i.e., relevant microbes and their metabolic activities), and how their presence and activity depend on environmental conditions. In this Perspective, we present the current understanding and recent methodological advances that can help to identify such links, even in complex environmental microbiomes and for contaminants present at low concentrations in complex chemical mixtures. We discuss the ensuing insights into contaminant biotransformation across varying environments and conditions and ask how much closer we have come to designing improved approaches to reducing environmental exposure to contaminants.
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| 4. |
- Ferreira-Rodríguez, Noé, et al.
(author)
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Freshwater Mussels as Sentinels for Safe Drinking Water Supply in Europe
- 2023
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In: ACS - ES & T Water. - : American Chemical Society (ACS). - 2690-0637. ; 3:12, s. 3730-3735
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Journal article (peer-reviewed)abstract
- In the context of the European Union (EU) Drinking Water Directive, freshwater mussels (Order Unionoida: Bivalvia) can help us face the challenges of safe drinking water provisions for all citizens in the EU. Specifically, the implementation of high frequency noninvasive (HFNI) valvometers allows the early detection of eventual pollution events in drinking water treatment plants. Currently real-time behavioral analysis is deployed in a number of EU countries, and we foresee a bright future as new technological advances are developed concerning HFNI valvometers.
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| 5. |
- Franke, Vera, et al.
(author)
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The Price of Really Clean Water: Combining Nanofiltration with Granular Activated Carbon and Anion Exchange Resins for the Removal of Per- And Polyfluoralkyl Substances (PFASs) in Drinking Water Production
- 2021
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In: ACS ES&T water. - : American Chemical Society (ACS). - 2690-0637. ; 1, s. 782-795
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Journal article (peer-reviewed)abstract
- The removal of per- and polyfluoroalkyl substances (PFASs) presents a challenge for drinking water providers. Guidelines for PFAS concentrations in final drinking water are regularly updated to ever-decreasing values, and conventional drinking water treatment plants are not designed to remove PFASs. Currently, the most frequently used removal technique, adsorption to granular activated carbon (GAC), is often considered challenging. High-pressure membranes, such as nanofiltration (NF), have been shown to remove PFASs efficiently. However, the creation of a waste stream comprised of at least 10% of the feedwater volume is recognized as a major drawback of this technique. In this study, a NF pilot plant was operated at a drinking water treatment plant in the city of Uppsala, Sweden, for six months. NF removed up to >98% of PFASs and fulfilled other water quality targets, such as the removal of uranium-238, dissolved organic carbon (DOC), and mineral hardness from the raw water. The concentrate from the pilot plant was treated with two different GAC materials and two different anion exchange (AIX) resins in column tests, where the superior performance of AIX over GAC was observed in terms of PFAS removal. PFAS adsorption curves for GAC were found to superimpose each other for the two water types if normalized to the specific throughput of DOC. The application of the freely available PHREEQC model revealed improvement possibilities in terms of resin properties. A cost analysis using the column test results compared GAC filtration to the combination of NF with adsorption materials. Treatment costs were found to be largely dependent on the PFAS drinking water treatment goals and concentrate discharge requirements, which highlight the economic consequences of prevailing guidelines for drinking water and discharge to the environment. The results of this study provide both the scientific community as well as drinking water providers with important insights into the application of NF for PFAS removal during drinking water treatment as well as that mechanistic and economic aspects of NF treatment and the management of the resulting concentrate.
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| 6. |
- Gault, Ian G. M., et al.
(author)
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Persistent Cytotoxicity and Endocrine Activity in the First Oil Sands End-Pit Lake
- 2023
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In: ACS - ES & T Water. - : American Chemical Society (ACS). - 2690-0637. ; 3:2, s. 366-376
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Journal article (peer-reviewed)abstract
- Oil sands process-affected water (OSPW) is a byproduct of bitumen extraction that has persistent toxicity owing to its complex mixture of organics. A prominent remediation strategy that involves aging OSPW in end-pit lakes and Base Mine Lake (BML) is the first full-scale test. Its effectiveness over the first 5 years was investigated here using real-time cell analysis, yeast estrogenic and androgenic screens (YES/YAS), and ultra-high-resolution mass spectrometry. HepG2 cytotoxicity per volume of BML organics extracted decreased with age; however, the toxic potency (i.e., toxicity per mass of extract) was not significantly different between years. This was consistent with mass spectral evidence showing no difference in chemical profiles, yet lower total abundance of organics in field-aged samples, suggestive that dilution explains the declining cytotoxicity in BML. The IC50’s of BML extracts for YES/YAS antagonism were at environmental concentrations and were similar despite differences in field-age. Persistent YES/YAS antagonism and cytotoxicity were detected in experimental pond OSPW field-aged >20 years, and while organic acids were depleted here, non-acid chemical classes were enriched compared to BML, suggesting these contribute to persistent toxicity of aged OSPW. To avoid a legacy of contaminated sites, active water treatment may be required to accelerate detoxification of end-pit lakes.
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| 7. |
- Hacker, Miriam E., et al.
(author)
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Hybrid Governance Arrangements for Urban Infrastructure Transitions : Comparing the Adoption of Onsite Water Reuse in San Francisco and New York City
- 2023
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In: ACS ES and T Water. - 2690-0637. ; 3:12, s. 3916-3928
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Journal article (peer-reviewed)abstract
- Decentralized water reuse technologies are increasingly being explored as a transformative approach for complementing centralized water and wastewater infrastructure. A transition to onsite water reuse requires a better understanding of how urban infrastructures are governed. While governance tends to be discussed within ideal types─i.e., hierarchy, market, and network─researchers increasingly recognize that infrastructure transitions often depend on hybrid mixtures of two or all three of those ideal types. This study draws on literature on the governance of infrastructure transitions as well as on the geography of sustainability transitions to introduce an analytical framework for assessing how the same technology─in this case, onsite water reuse─is implemented with different hybrid governance arrangements in different cities. By juxtaposing the transition trajectory to onsite water reuse in San Francisco and New York City, we empirically illustrate two ideal-type hybrid governance arrangements that systematically differ in terms of key actor types and coordination mechanisms.
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| 8. |
- Hanson, Blair, et al.
(author)
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DOM Molecular Weight Fractionation and Fluorescence Quantum Yield Assessment Using a Coupled In-Line SEC Optical Property System
- 2022
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In: ACS ES and T Water. - : American Chemical Society (ACS). - 2690-0637. ; 2:12, s. 2491-2501
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Journal article (peer-reviewed)abstract
- Size exclusion chromatography (SEC) in combination with optical measurements has become a popular form of analysis to characterize dissolved organic matter (DOM) as a function of molecular size. Here, SEC coupled with in-line absorbance scans and fluorescence emission scans was utilized to derive apparent fluorescence quantum yield (φf) as a function of molecular weight (MW) for DOM. Individual instrument-specific SEC-fluorescence detector correction factors were developed by comparison of an SEC-based excitation emission matrix (EEM) to an EEM generated by a calibrated benchtop fluorometer. The method was then applied to several sample sets to demonstrate how to measure the φf of unknown DOM samples and to observe changes to φf following a processing mechanism (ozonation). The φf of riverine water samples and DOM fulvic acid isolates from Suwannee River and Pony Lake increased from < 0.5% to a maximum of 2.5-3% across the medium- to low-MW range. Following ozonation of PLFA, φf increased most notably in the large-MW fractions (elution volumes < 40 mL). Overall, this method provides a means by which highly fluorescent size fractions of DOM can be identified for more detailed analyses of chemical composition and its changes through different processing mechanisms.
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| 9. |
- Li, Siyu, et al.
(author)
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Distinct Non-conservative Behavior of Dissolved Organic Matter after Mixing Solimoes/Negro and Amazon/Tapajo s River Waters
- 2023
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In: ACS - ES & T Water. - : AMER CHEMICAL SOC. - 2690-0637. ; 3:8, s. 2083-2095
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Journal article (peer-reviewed)abstract
- Positive and negative electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and H-1 NMR revealed major compositional and structural changes of dissolved organic matter (DOM) after mixing two sets of river waters in Amazon confluences: the Solimoes and Negro Rivers (S + N) and the Amazon and Tapajo s Rivers (A + T). We also studied the effects of water mixing ratios and incubation time on the composition and structure of DOM molecules. NMR spectra demonstrated large-scale structural transformations in the case of S + N mixing, with gain of pure and functionalized aliphatic units and loss of all other structures after 1d incubation. A + T mixing resulted in comparatively minor structural alterations, with a major gain of small aliphatic biomolecular binding motifs. Remarkably, structural alterations from mixing to 1d incubation were in essence reversed from 1d to 5d incubation for both S + N and A + T mixing experiments. Heterotrophic bacterial production (HBP) in endmembers S, N, and S + N mixtures remained near 0.03 mu gC L-1 h(-1), whereas HBP in A, T, and A + T were about five times higher. High rates of dark carbon fixation took place at S + N mixing in particular. In-depth biogeochemical characterization revealed major distinctions between DOM biogeochemical changes and temporal evolution at these key confluence sites within the Amazon basin.
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| 10. |
- Lu, Lu, et al.
(author)
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Rhamnolipid Biosurfactants Enhance Microbial Oil Biodegradation in Surface Seawater from the North Sea
- 2023
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In: ACS - ES & T Water. - : American Chemical Society (ACS). - 2690-0637. ; 3:8, s. 2255-2266
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Journal article (peer-reviewed)abstract
- This study provides strong evidence thatthe biosurfactantrhamnolipid is more efficient than the widely used chemical dispersantsCorexit 9500 and Slickgone NS in stimulating oil biodegradation innatural seawater. Biosurfactants arepromising alternatives to chemical dispersantsfor combating marine oil spills; however, the impacts of biosurfactantson microbial community composition and oil biodegradation activitiesremain largely unknown. Here, we conducted a time-course microcosmexperiment mimicking oil spill scenarios with surface seawater fromthe North Sea, amended with either the biosurfactant rhamnolipid ora dispersant (Corexit 9500 or Slickgone NS). Radioactive tracer assaysto track hexadecane and naphthalene oxidation as well as bacterialproduction revealed the highest hydrocarbon oxidation rates and generalmicrobial activities in the rhamnolipid-amended oil microcosms, followedby oil microcosms with Slickgone and Corexit. Impacts on the microbialcommunity composition differed among treatments, and growth of oil-degrading Colwellia was stimulated remarkably in Corexit-amended oiland oil-only microcosms, while potential oil-degrading Oleispira were highly enriched in the presence of oil in combination withrhamnolipid or Slickgone. Furthermore, increased abundances of Colwellia and Oleispira, and stimulatedbacterial production in microcosms with only rhamnolipid, Corexit,or Slickgone, indicated their involvement in biosurfactant/dispersantbiodegradation. Our findings highlight varying microbial impacts resultingfrom rhamnolipid and chemical dispersants and suggest great promisefor the application of biosurfactants in future marine oil spills.
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