| 1. |
- Ahrens, Lutz
(författare)
-
Exploring the adsorption of short and long chain per- and polyfluoroalkyl substances (PFAS) to different zeolites using environmental samples
- 2023
-
Ingår i: Environmental Science: Water Research & Technology. - 2053-1400 .- 2053-1419.
-
Tidskriftsartikel (refereegranskat)abstract
- Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants that are gaining attention for their ubiquitous distribution, persistence, and toxicity in the environment and ecosystem. Among the PFAS removal techniques from water, adsorption treatment techniques are considered most promising. In this study for the first time, 9 different zeolites and powdered activated carbon (PAC) were tested for 18 PFAS including C-3-C-13 perfluoroalkyl carboxylates acids (PFCAs), C-4, C-6, C-8 perfluoroalkane sulfonates (PFSA), three fluorotelomer sulfonate (FTSAs), and perfluorooctane sulfonamide (FOSA) in batch sorption experiments using ultrapure and real environmental water samples. Adsorption experiments showed that zeolite beta with SAR = 25 (silica alumina ratio, SiO2/Al2O3) (99.5% n-ary sumation PFAS uptake) and SAR = 300 (99.2% n-ary sumation PFAS uptake), and mordenite with SAR = 240 (87.8% n-ary sumation PFAS uptake) were the most promising adsorbent media. Sorption of individual PFAS depended on the perfluoroalkyl chain length, functional group and molecule size. Overall, AgY390 and AgY760 silver (Ag) functionalized zeolites (76.4% and 78.3% n-ary sumation PFAS uptake respectively) showed better uptake capacity for PFAS compared to the as-synthetized Y390 and Y760 (68.6% and 68.3% n-ary sumation PFAS uptake respectively), and could favor catalytic reactions in PFAS degradation. PFAS sorption to PFAS-fortified real contaminated water samples was as follows: Beta25 (99.4%) < Beta360 (97.5%) < MOR (97.1%) < Y760 (95.5%) < CHA (71.4%) (with respect to PAC 99.9%). X-ray structural data revealed that changes in unit cell parameters arise from channel distortions caused by the encapsulation of PFAS inside the zeolites cages. Thermal analyses corroborate these results and revealed degradation of the perfluoroalkyl chain and expulsion upon heating are accompanied by exothermic reactions registered in the differential thermal analysis (DTA). The features of the zeolites, including the specific surface area, pores size and distribution, SAR, temperature, presence of extraframework cations and polarity significantly affected their PFAS adsorption capacity.
|
|
| 2. |
- Ahrens, Lutz
(författare)
-
Themed issues on per- and polyfluoroalkyl substances
- 2019
-
Ingår i: Environmental science: water research & technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 5, s. 1808-1813
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Guest editors Lutz Ahrens, Jonathan Benskin, Ian Cousins, Michelle Crimi and Christopher Higgins introduce the "Per- and polyfluoroalkyl substances (PFASs)" themed issue.
|
|
| 3. |
- Almstrand, Robert
(författare)
-
Succession of founding microbiota in an anaerobic baffled bioreactor treating low-temperature raw domestic wastewater
- 2022
-
Ingår i: Environmental Science: Water Research & Technology. - : Royal Society of Chemistry (RSC). - 2053-1400 .- 2053-1419. ; 8, s. 792-806
-
Tidskriftsartikel (refereegranskat)abstract
- Continuously operated pilot- and full-scale anaerobic baffled reactors (ABRs) treating low-temperature raw domestic wastewater are currently few in number but offer significant advantages. As ABRs treating domestic wastewater become more prevalent, engineers and operators face the practical challenge of effectively transferring and seeding anaerobic sludge from existing "donor" ABRs to newly constructed ABRs. Unlike activated sludge, which predominantly consists of relatively fast-growing aerobic heterotrophic bacteria, anaerobic microbiota are slower-growing and the community structure may be impacted by process disturbances during bioreactor start-up. Examining the spatiotemporal development of anaerobic microbiota after transfer can enhance understanding of start-up dynamics in engineered anaerobic bioreactor systems. To understand the impacts of sludge transfer and seeding from an existing ABR operated for 3.5 years treating raw, low-temperature domestic wastewater to a new, similarly configured ABR treating a different raw domestic wastewater stream, influent wastewater and sludge microbiota samples were withdrawn biweekly for 275 days and used to characterize changes to the microbial community structure over time in both ABRs. Results suggest that the donor ABR communities maintained relatively consistent structure over time, but the microbial communities in the receiving bioreactor experienced two apparent successional trajectories post-inoculation. The first trajectory, which lasted for similar to 120 days, showed increasing divergence between communities in the two ABRs. This trajectory was marked by lower wastewater temperatures (12-14 degrees C, with extreme lows of 8 degrees C) and numerous disturbances to the sludge blankets. A second successional trajectory, observed when wastewater temperatures increased (>16 degrees C) and disturbances were eliminated, was marked by significant increases in the relative abundance of Euryarchaeota, especially Methanosaeta ("Methanothrix"), and increasing convergence of microbial communities in complementary donor and receiving bioreactor compartments. Further, the relative abundance of founding microbial community members significantly decreased during the first successional trajectory but significantly increased, or rebounded, during the second successional trajectory. The results of this study indicate that an anaerobic sludge inoculum can be effectively transferred from a long-running ABR treating raw, low-temperature domestic wastewater to a new ABR, and that similar performance can be achieved despite differing environmental conditions and disturbances to the sludge blanket microbial communities during start-up of the new ABR.
|
|
| 4. |
- Andersson, Anna, et al.
(författare)
-
Molecular changes among non-volatile disinfection by-products between drinking water treatment and consumer taps
- 2021
-
Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; 7:12, s. 2335-2345
-
Tidskriftsartikel (refereegranskat)abstract
- The formation of disinfection by-products (DBPs) during drinking water treatment has been associated with various health concerns but the total DBP exposure is still unknown. In this study, molecular level non-target analysis by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to study non-volatile DBPs, and how their composition changes during water distribution in four drinking water treatment plants (DWTPs) in Sweden using different types of raw water and disinfection processes. The largest portion of tap water DBP compositions were detected also at the DWTPs, highlighting that these DBP formulae were rather stable and contribute to human DBP exposure. Yet the number of detected DBPs decreased 14-48% between drinking water treatment and consumer taps in the three plants in which no mixing of water from other DWTPs in the distribution system occurred showing active DBP processing in the water distribution network. While considerable amounts of bromine-containing DBPs were detected upon chemical disinfection in some DWTPs, few of them were detected in the tap water samples, likely due to debromination by hydrolytic reactions. The overall fewer non-volatile DBPs detected in tap waters, along with changed distribution among chlorine and bromine DBPs, demonstrate that DBP mixtures are highly dynamic and that DBP measurements at DWTPs do not adequately reflect exposure at the point-of-use. Clearly, more knowledge about changes of DBP mixtures through the distribution system is needed to improve DBP exposure assessments.
|
|
| 5. |
- Andersson, Anna, et al.
(författare)
-
Selective removal of natural organic matter during drinking water production changes the composition of disinfection by-products
- 2020
-
Ingår i: Environmental Science. - : ROYAL SOC CHEMISTRY. - 2053-1400 .- 2053-1419. ; 6:3, s. 779-794
-
Tidskriftsartikel (refereegranskat)abstract
- Disinfection by-products (DBPs) are potentially toxic compounds formed upon chemical disinfection of drinking water. Controlling the levels and characteristics of dissolved organic matter (DOM) as precursor material for DBPs is a major target to reduce DBP formation. A pilot-scale treatment including suspended ion exchange (SIX (R)), a ceramic microfilter (CeraMac (R)) with in-line coagulation and optional pre-ozonation followed by granular activated carbon (GAC) filtration was compared with a conventional full-scale treatment based on DOM removal and DBP formation using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), rapid fractionation, liquid chromatography organic carbon detection (LC-OCD), adsorbable organic halogens (AOX) and trihalomethane (THM) analysis. The new treatment combination showed different selectivity for DOM removal, compared to the conventional, leading to changes in composition of the DBPs formed. SIX (R) and GAC had the largest impacts on reducing AOX and THM formation potentials but the high adsorptive capacity of GAC affected the diversity of detected DBPs most. Chlorination and chloramination of pilot treated water with doses normally used in Sweden produced low levels of AOX compared to the full-scale treatment, but FT-ICR MS revealed an abundance of brominated DBP species in contrast with the conventional treatment, which were dominated by chlorinated DBPs. This finding was largely linked to the high DOM removal by the pilot treatment, causing an increased Br-/C ratio and a higher formation of HOBr. Potential increases in Br-DBPs are important to consider in minimizing health risks associated with DBPs, because of the supposed higher toxicity of Br-DBPs compared to Cl-DBPs.
|
|
| 6. |
- Andersson, Anna, et al.
(författare)
-
Waterworks-specific composition of drinking water disinfection by-products
- 2019
-
Ingår i: Environmental Science. - Cambridge : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; :5, s. 861-872
-
Tidskriftsartikel (refereegranskat)abstract
- Reactions between chemical disinfectants and natural organic matter (NOM) upon drinking water treatment result in formation of potentially harmful disinfection by-products (DBPs). The diversity of DBPs formed is high and a large portion remains unknown. Previous studies have shown that non-volatile DBPs are important, as much of the total toxicity from DBPs has been related to this fraction. To further understand the composition and variation of DBPs associated with this fraction, non-target analysis with ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to detect DBPs at four Swedish waterworks using different types of raw water and treatments. Samples were collected five times covering a full year. A common group of DBPs formed at all four waterworks was detected, suggesting a similar pool of DBP precursors in all raw waters that might be related to phenolic moieties. However, the largest proportion (64–92%) of the assigned chlorinated and brominated molecular formulae were unique, i.e. were solely found in one of the four waterworks. In contrast, the compositional variations of NOM in the raw waters and samples collected prior to chemical disinfection were rather limited.This indicated that waterworks-specific DBPs presumably originated from matrix effects at the point of disinfection, primarily explained by differences in bromide levels, disinfectants (chlorine versus chloramine) and different relative abundances of isomers among the NOM compositions studied. The large variation of observed DBPs in the toxicologically relevant non-volatile fraction indicates that non-targeted monitoring strategies might be valuable to ensure relevant DBP monitoring in the future.
|
|
| 7. |
- Aqeel, Hussain, et al.
(författare)
-
Drivers of bioaggregation from flocs to biofilms and granular sludge
- 2019
-
Ingår i: Environmental Science: Water Research and Technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 5:12, s. 2072-2089
-
Forskningsöversikt (refereegranskat)abstract
- Microorganisms in natural and engineered environments interact with surfaces and form aggregates consisting of cells and an extracellular matrix. The design of the process and appropriate operational conditions drive the formation of these biofilms, flocs, and granular structures. The application of granular sludge technologies for nutrient removal is relatively new. Although research and practice benefit from several decades of investigation of biofilm and anaerobic granular sludge systems, a thorough understanding of factors affecting granulation is only beginning to emerge from bench, pilot, and full-scale investigations. Challenges intrinsic to maintaining granular and biofilm structures include management of resistance to substrate transport, establishment of targeted microbial niches, role of extracellular polymeric substances, and impacts of toxic compounds, among others. There is increasing recognition of the potential value of hybrid process configurations that optimize interactions between flocs, granules, and/or biofilm features for process enhancement and robustness. While these structures appear distinct, it is not uncommon to find a mixture of these structures present in a single system and dynamics leading to a transition from one structure to another. The transitions are dependent on changes in the microbial community and properties of the extracellular matrix. This review focuses on the drivers affecting formation and stability of flocs, biofilms, and granules and conditions that support integrated technologies for biological wastewater treatment.
|
|
| 8. |
- Byrne, D. M., et al.
(författare)
-
Life cycle assessment (LCA) of urban water infrastructure: emerging approaches to balance objectives and inform comprehensive decision-making
- 2017
-
Ingår i: Environmental Science: Water Research and Technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 3:6, s. 1002-1014
-
Tidskriftsartikel (refereegranskat)abstract
- Life cycle assessment (LCA) has been widely used to quantify environmental impacts associated with urban water infrastructure, including wastewater, drinking water, stormwater, and integrated urban water systems. While LCA is applicable for the estimation of global environmental impacts, decision-makers must balance these impacts with local, often regulated, environmental and public health objectives. To characterize the state of the art for the use of LCA for urban water infrastructure, a thorough literature review was conducted of papers that applied LCA to wastewater (173 papers), drinking water (44 papers), stormwater (17 papers), and integrated urban water (22 papers) systems. Analyses revealed current preferences for functional unit basis (e.g., volume for wastewater), system boundaries (e.g., focus on operation), and impact assessment methodology (CML, ReCiPe, and Eco-Indicator). Based on these findings, LCA methodological recommendations for urban water infrastructure are made, and emerging opportunities to balance objectives and inform comprehensive decision-making are discussed. Critical opportunities include the integration of spatial considerations (e.g., spatialized characterization factors), water quantity (e.g., water quantity indicators), public health (e.g., integration with risk assessment), economic and social assessments (e.g., life cycle costing and social LCA), along with prioritization of continuous stakeholder engagement. Finally, research and development needs specific to the use of LCA for urban water infrastructure (e.g., development of new indicators coupled with case studies) are prioritized.
|
|
| 9. |
- Cascone, C., et al.
(författare)
-
AbspectroscoPY, a Python toolbox for absorbance-based sensor data in water quality monitoring
- 2022
-
Ingår i: Environmental Science. - : Royal Society of Chemistry (RSC). - 2053-1400 .- 2053-1419. ; 8:4, s. 836-848
-
Tidskriftsartikel (refereegranskat)abstract
- The long-term trend of increasing natural organic matter (NOM) in boreal and north European surface waters represents an economic and environmental challenge for drinking water treatment plants (DWTPs). High-frequency measurements from absorbance-based online spectrophotometers are often used in modern DWTPs to measure the chromophoric fraction of dissolved organic matter (CDOM) over time. These data contain valuable information that can be used to optimise NOM removal at various stages of treatment and/or diagnose the causes of underperformance at the DWTP. However, automated monitoring systems generate large datasets that need careful preprocessing, followed by variable selection and signal processing before interpretation. In this work we introduce AbspectroscoPY (“Absorbance spectroscopic analysis in Python”), a Python toolbox for processing time-series datasets collected by in situ spectrophotometers. The toolbox addresses some of the main challenges in data preprocessing by handling duplicates, systematic time shifts, baseline corrections and outliers. It contains automated functions to compute a range of spectral metrics for the time-series data, including absorbance ratios, exponential fits, slope ratios and spectral slope curves. To demonstrate its utility, AbspectroscoPY was applied to 15-month datasets from three online spectrophotometers in a drinking water treatment plant. Despite only small variations in surface water quality over the time period, variability in the spectrophotometric profiles of treated water could be identified, quantified and related to lake turnover or operational changes in the DWTP. This toolbox represents a step toward automated early warning systems for detecting and responding to potential threats to treatment performance caused by rapid changes in incoming water quality.
|
|
| 10. |
- Ekholm, Jennifer, 1992, et al.
(författare)
-
Full-scale aerobic granular sludge for municipal wastewater treatment - granule formation, microbial succession, and process performance
- 2022
-
Ingår i: Environmental Science: Water Research and Technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 8:12, s. 3138-3154
-
Tidskriftsartikel (refereegranskat)abstract
- Aerobic granular sludge (AGS) plants have gained growing interest and application due to their low energy demand, small footprint, and low operational costs. However, the fulfilment of strict discharge limits for nitrogen and phosphorus, vast seasonal temperature variations, and large peaks in influent flows may pose challenges to the implementation of AGS. Moreover, the knowledge about microbial community assembly and process performance under varying environmental conditions in full-scale reactors is still limited. In this study, the first implementation of the AGS process in the Nordic countries was assessed. In two full-scale AGS reactors with different seeding sludges, the start-up was associated with rapid changes in microbial community composition in both, but only successful granulation in one. As a consequence, the non-granulated reactor was eventually reseeded with biomass from the better granulated reactor. This resulted in a convergence of the microbial communities in the two reactors with the maintenance of stable sludge concentrations (6-8 g L-1) with large granules (50-80% with diameter >2 mm) and fast settling of biomass (SVI30/SVI10 of 0.9-1). Immigration from the influent wastewater was a minor factor affecting the microbial community once the granules had formed, while the seasonal variations in environmental factors were identified as important. Key guilds of AOB (Nitrosomonas), NOB (mainly Ca. Nitrotoga), PAOs (mainly Tetrasphaera), and GAOs (mainly Ca. Competibacter) varied considerably in abundance throughout the study period. After 15 months, stable organic matter, nitrogen, and phosphorus removal were attained with low effluent concentrations. During the start-up, the BOD7/N ratio, influent flow, and temperature were important factors influencing the performance of the AGS.
|
|
| 11. |
- Franke, Vera, et al.
(författare)
-
Efficient removal of per- and polyfluoroalkyl substances (PFASs) in drinking water treatment: nanofiltration combined with active carbon or anion exchange
- 2019
-
Ingår i: Environmental science: water research & technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 5, s. 1836-1843
-
Tidskriftsartikel (refereegranskat)abstract
- Society's increasing use of chemicals poses a challenge for drinking water producers. Accepted concentrations for per- and polyfluoroalkyl substances (PFASs) in finished water are lower than ever before with new regulations often enacted based on findings made possible by improved analytical techniques and correspondingly justified health concerns. Nanomembrane filtration removes compounds, including PFASs, based primarily on size-exclusion, however, treatment and/or disposal of PFAS laden membrane concentrate remains a challenge. This study combined feedwater nanofiltration with granular activated carbon (GAC) and anion exchange (AIX) for concentrate treatment. Nanofiltration removed PFAS concentrations on average by 99% including some PFASs with molecular weights smaller than the membrane nominal cutoff of 270 Da, indicating membrane rejection mechanisms additional to size-exclusion. Treatment of raw water and concentrate was compared in column tests. AIX showed up to threefold greater half-time of saturation than GAC, however with a higher rate of decreasing efficiency, while GAC removed approximately 20% of incoming PFAS concentrations consistently after treatment of 15 000 bed volumes (BVs). Overall, GAC and AIX removed 2.6-fold and 4.1-fold more PFAS mass per adsorbent volume from the concentrated retentate than from raw water indicating that the combination of nanofiltration with GAC or AIX increases the efficiency of the adsorbent materials in comparison to only using GAC or AIX filters.
|
|
| 12. |
- Franke, Vera, et al.
(författare)
-
Removal of per- and polyfluoroalkyl substances (PFASs) from tap water using heterogeneously catalyzed ozonation
- 2019
-
Ingår i: Environmental science: water research & technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 5, s. 1887-1896
-
Tidskriftsartikel (refereegranskat)abstract
- Drinking water is one of the most important human exposure pathways of per- and polyfluoroalkyl substances (PFASs). As conventional water treatment techniques are unable to remove PFASs efficiently, novel treatment methods for the removal of PFASs in water are urgently needed. In the present study advanced oxidation processes (AOPs) based on heterogeneously catalyzed ozonation were evaluated on laboratory- and pilot-scales for their efficiency in removing PFASs from water. Laboratory-scale ozonation experiments were conducted with different combinations of ozone, a catalyst and persulfate and showed the highest efficiency for the treatment combining all three parameters. The method was further evaluated for the treatment of spiked drinking water on the pilot-scale. The concentrations of all 18 analyzed PFASs decreased significantly within three hours of treatment in the pilot-scale set-up. The perfluorocarbon chain length had a dominant influence on the removal efficiency, where CF7 - CF11 PFASs were removed with more than 98% removal efficiency, independent of the functional group, CF12 - CF17 PFASs with 64%, and CF4 - CF6 with 55% on average. As the evaluated ozonation treatment is already commercially available for large scale applications today, it could easily be applied in existing water treatment trains; however, ozonation can create potentially toxic transformation products which needs to be investigated in future research.
|
|
| 13. |
- Furén, Robert, Industridoktorand, et al.
(författare)
-
Concentration, distribution, and fractionation of metals in the filter material of 29 bioretention facilities: a field study
- 2023
-
Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; 9:12, s. 3158-3173
-
Tidskriftsartikel (refereegranskat)abstract
- Pollutant loads stemming from anthropogenic activities conveyed in urban stormwater runoff contribute to the impairment of downstream water bodies. Cities and municipalities are increasingly turning toward green infrastructure stormwater control measures to treat pollutants at the source of runoff. One example of these technologies is bioretention, which is commonly applied for stormwater treatment in urban areas due to its demonstrated effectiveness in removing various pollutants from water, including sediment, nutrients (e.g., N and P), and metals. As metals are mainly removed by filtration or adsorption to soil particles, the filter media is important for metal removal in bioretention. However, the capacity to remove metals through adsorption by bioretention media is finite; thus, the media may need to be replaced and disposed of after maintenance or at the end of its operational lifespan. Pollutant accumulation in bioretention media has the potential to approach toxicity thresholds, which may introduce complexities for safe handling and disposal. To fully capture the potential challenges associated with metals accumulation in media over time, it is important to understand the accumulation processes and mobility of metals in bioretention facilities as they age. Although several studies have investigated metal accumulation and distribution in bioretention media, few have assessed metal mobility by fractionation using sequential extraction methods in older (i.e., >7 years) facilities. In November 2019, we conducted a comprehensive field study of older facilities in Ohio, Michigan, and Kentucky (USA) to improve the understanding of the accumulation processes and metal mobility in bioretention. In this study, concentrations of several metals (i.e., Cr, Cu, Ni, Pb, and Zn) were analyzed in samples of filter material from 29 bioretention sites in operation for 7–16 years. Except for Cd, all metals were found in all samples. Metals accumulation was clear with highest concentrations found in the top (0–5 cm) layer of the filter material, attributable to the filtration of particles percolating through the media profile. Lower concentrations were observed in deeper (i.e., >10 cm) layers of the bioretention media. The fractionation showed that the metals of interest were present at high levels with a risk of leaching over time, among which Cd, Zn, and Pb were suggested to be mobile from the filter material during precipitation. Thus, there is a potential risk of leakage from filter material or sediment removed from biofilters, e.g., during maintenance and disposal. The results of principal component analysis indicated specifically correlations between metal concentrations and the filter material soil texture including the organic matter content. These results contribute to improved design and operation and suggest regular maintenance to reduce long-term risks associated with the accumulation of metals in bioretention and similar urban stormwater treatment facilities. Since most metals are trapped in the top layer of the filter it may be enough to remove only the top layer. However, metal fractionation should be considered when handling the material.
|
|
| 14. |
- Hoffmeister, Svenja, et al.
(författare)
-
Evaluating the accuracy of two in-situ optical sensors to estimate DOC concentrations for drinking water production
- 2020
-
Ingår i: Environmental Science: Water Research and Technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 6:10, s. 2891-2901
-
Tidskriftsartikel (refereegranskat)abstract
- Two in situ optical sensors, a single-excitation fluorescence-based sensor (fDOM) mounted on a multi-parameter EXO2 sonde (YSI), and a stand-alone, multispectral absorbance-based instrument (spectro::lyser, scan Messtechnik GmbH), were evaluated for their capability to (i) estimate river dissolved organic carbon (DOC) concentrations and (ii) provide oversight of drinking water production. The sensors were deployed between March and November 2017 in the river Fyris, which drains a mixed forested and agricultural 2003 km2 catchment and serves as a drinking water source by managed aquifer recharge. Grab samples were collected every 2 to 3 weeks and compared with logged sensor data collected at 15 minute intervals. The fDOM probe signal was used to estimate DOC concentrations in the range of 10.4 to 24.4 mg L−1 using linear regression (R2 = 0.71, RMSE = 2.5 mg L−1), after correction for temperature, turbidity and inner-filter effects. Temporal changes in DOC character associated with the mixed land use landscape, as indicated by optical indices, reduced this sensor accuracy for estimating DOC concentration. Nevertheless, humic substance concentrations, the fraction of DOC that is preferentially removed during artificial infiltration, were well captured. The spectrolyser signal was used to establish a 2-component partial least square model that captured DOC fluctuations from 10.2 to 29.4 mg L−1 (R2 = 0.92; RMSE = 1.3 mg L−1). This multiple-wavelength model (220 to 720 nm) effectively handled the changes in DOC composition while accurately estimating DOC concentrations. This study explores the advantages and limitations of optical sensors for their use in managed aquifer recharge and drinking water production in relation to DOC levels.
|
|
| 15. |
- Hägg, Kristofer, et al.
(författare)
-
Water quality changes during the first meter of managed aquifer recharge
- 2021
-
Ingår i: Environmental Science: Water Research and Technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 7:3, s. 562-572
-
Tidskriftsartikel (refereegranskat)abstract
- The capacity of an artificial recharge field to alter organic matter and the bacterial flora of surface water was assessed by following changes in bacterial communities and composition of natural organic matter (NOM) over the first meter of infiltration depth. The sampling strategy applied in this study ensured that water samples consisted only of infiltrated water, excluding natural groundwater. Water was sampled at 50 and 100 cm below the surface of an infiltration basin divided into two halves; one side was dried and frozen and one was infiltrating water during the winter period prior to the sampling period. Bacterial cell counts, proportions of intact cells and community fingerprints were determined by flow cytometry, and NOM was characterized using total organic carbon (TOC), UV254 nm-absorbance (UVA) and fluorescence spectroscopy. Around 40% of the NOM was removed after only 50 cm. Protein-like components were reduced to a larger extent (45-50%) than the humic-like components (25%), suggesting removal of mostly biodegradable fractions of NOM. After only 50 cm of infiltration, about 99% total cell count (TCC) was removed. The flow cytometric data revealed that the bacterial communities collected after infiltration from the basin area that had been dried and frozen were more similar to those in the raw water. This suggests that drying and freezing the basin negatively impacted its treatment capacity. The results from this study highlight the importance of a well-developed biofilm and unsaturated zone for artificial recharge.
|
|
| 16. |
- Khaliha, Sara, et al.
(författare)
-
Upcycling of plastic membrane industrial scraps and reuse as sorbent for emerging contaminants in water
- 2024
-
Ingår i: Environmental Science: Water Research and Technology. - 2053-1419 .- 2053-1400. ; 10:5, s. 1097-1107
-
Tidskriftsartikel (refereegranskat)abstract
- Scraps obtained as waste of the industrial production of polysulfone and polysulfone-graphene oxide hollow fiber membranes (PSU-HF and PSU-GO-HF, respectively) were converted into granular materials and used as sorbents of several classes of emerging and standard water contaminants, such as drugs, heavy metal ions, and a mixture of per- and poly-fluoroalkyl substances (PFASs). The millimetric sized granules (PSU and PSU-GO, respectively) outperformed granular activated carbon (GAC), the industrial sorbent benchmark, in the adsorption of lead, diclofenac, and PFOA from tap water. Adsorption mechanism insight was achieved by molecular dynamics simulations, demonstrating the key role of graphene oxide (GO) on PSU-GO material performance. With respect to GAC, PSU-GO adsorption capacity was two times higher for diclofenac and PFOA and ten times higher for lead. Material safety was assessed by surface enhanced Raman spectroscopy, excluding GO nanosheets leaching, and combined potability test. Overall, our work proves that scrap conversion and reuse is a valuable strategy to reduce plastic industrial waste disposal and to integrate standard technology for enhanced water purification.
|
|
| 17. |
- Mantovani, Sebastiano, et al.
(författare)
-
Amino acid-driven adsorption of emerging contaminants in water by modified graphene oxide nanosheets
- 2023
-
Ingår i: Environmental Science: Water Research and Technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 9:4, s. 1030-1040
-
Tidskriftsartikel (refereegranskat)abstract
- Graphene oxide nanosheets have shown promising adsorption properties toward emerging organic contaminants in drinking water. Here, we report a family of graphene oxide nanosheets covalently modified with amino acids and the study on their adsorption properties toward a mixture of selected contaminants, including pharmaceuticals, additives, and dyes. Graphene oxides modified with l-glutamic acid and l-methionine (GO-Glu and GO-Met) were synthesized and purified with a scalable and fast synthetic and purification procedure, and their structure was studied by combined X-ray photoelectron spectroscopy and elemental analysis. An amino acid loading of about 5% and a slight reduction (from 27% down to 14-20% oxygen) were found and associated with the adsorption selectivity. They were compared to unmodified GO, reduced GO (rGO), GO-lysine, and to the reference sample GO-NaOH. Each type of modified GO possesses a higher adsorption capacity toward bisphenol A (BPA), benzophenone-4 (BP4), and carbamazepine (CBZ) than standard GO and rGO, and the adsorption occurred within the first hour of contact time. The maximum adsorption capacity (estimated from the adsorption isotherms) was strictly related to the amino acid loading. Accordingly, molecular dynamics simulations highlighted higher interaction energies for the modified GOs than unmodified GO, as a result of higher van der Waals and hydrophobic interactions between the contaminants and the amino acid side chains on the nanosheet surface.
|
|
| 18. |
- Mautner, Andreas, et al.
(författare)
-
Nitrate removal from water using a nanopaper ion-exchanger
- 2016
-
Ingår i: Environmental Science. - : Royal Society of Chemistry (RSC). - 2053-1400 .- 2053-1419. ; 2, s. 117-124
-
Tidskriftsartikel (refereegranskat)abstract
- Nitrates seriously affect drinking water quality. We herein present a process for the efficient removal of nitrates from water using a nanopaper ion-exchanger, which can be operated in flow-through conditions. The nanopaper ion-exchanger was produced from nanofibrillated cellulose obtained from fibre sludge, a paper-production waste stream, using a simple paper-making process. The cellulose nanofibrils were modified with quaternary trimethylammonium groups. The performance of these cationic nanopaper ion-exchangers was assessed with respect to their permeance and nitrate adsorption. Nitrates could be successfully captured onto the cationic nanopaper and thus rejected from contaminated water during dynamic filtration experiments. The ion-exchange nanopaper had adsorption capacities in the range of commercial available adsorbers but with the advantage of reduced contact time.
|
|
| 19. |
- McLachlan, Michael S., et al.
(författare)
-
Removal of 293 organic compounds in 15 WWTPs studied with non-targeted suspect screening
- 2022
-
Ingår i: Environmental Science. - : Royal Society of Chemistry (RSC). - 2053-1400 .- 2053-1419. ; 8:7, s. 1423-1433
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding how contaminant breakthrough in wastewater treatment plants is influenced by chemical structure and treatment technology is important for protecting the aquatic environment. In order to assess this question, consistent contaminant breakthrough measurements are required for a large number of chemicals. Using direct injection UHPLC-Orbitrap-MS/MS with data-dependent non-target data acquisition followed by suspect screening against a library of >7000 compounds with exact mass and MS2 spectra, we quantified the removal of 293 chemicals in 15 WWTPs with widely varying treatment technology. Principle component analysis showed a clear and consistent influence of treatment technology on contaminant breakthrough. Log breakthrough was significantly correlated with log TSS and log BOD in treated effluent for 71% and 68% of the chemicals, respectively. Chemicals were identified which could be used as indicators of the standard of wastewater treatment. Furthermore, chemicals were identified that could be used to predict the breakthrough of groups of other chemicals. A high degree of correlation was found for the breakthrough of different groups of chemicals, which suggests that the data could be used to develop models describing how chemical structure influences breakthrough or removal efficiency. Non-targeted suspect screening is a useful method for generating consistent WWTP breakthrough data for large numbers of chemicals.
|
|
| 20. |
- Mirabediny, Maryam, et al.
(författare)
-
Fast reductive defluorination of branched perfluorooctane sulfonic acids by cobalt phthalocyanine : electrochemical studies and mechanistic insights
- 2024
-
Ingår i: Environmental Science. - 2053-1400 .- 2053-1419. ; 10:1, s. 216-227
-
Tidskriftsartikel (refereegranskat)abstract
- Branched perfluorooctane sulfonic acid (PFOS) is recognized as a threatening environmental pollutant due to its high persistence and bioaccumulation in various environmental matrices as well as for its toxic effects on humans and wildlife even at very low concentrations. This study reports the first investigation of branched PFOS defluorination catalyzed by metal phthalocyanines. The reaction conditions were optimized using different reductants and temperatures. CobaltII phthalocyanine, when combined with TiIII citrate as a reducing agent, was able to defluorinate 10.9% of technical PFOS within 8 hours. In contrast, vitamin B12 only showed 2.4% defluorination during the same time period, under similar conditions. The defluorination mediated by the cobaltII phthalocyanine and TiIII citrate system corresponds to 54.5% of all branched PFOS isomers (br-PFOS isomers). Isomer-specific degradation was also investigated via high-resolution LC-orbitrap followed by their relative rates. The difference in catalytic efficacy of various phthalocyanine complexes is rationalized by their structures and electrochemical response. Lastly, a new defluorination mechanism is proposed based on the newly detected degradation products after the phthalocyanine treatment and previous studies. CobaltII phthalocyanine in the presence of TiIII citrate acts as an efficient reducing agent which was able to defluorinate 54.5% of all branched PFOS isomers.
|
|
| 21. |
- Modin, Oskar, 1980, et al.
(författare)
-
Three promising applications of microbial electrochemistry for the water sector
- 2017
-
Ingår i: Environmental Science: Water Research and Technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 3:3, s. 391-402
-
Tidskriftsartikel (refereegranskat)abstract
- Microbial electrochemical technologies are based on the interactions between living microorganisms and electrodes. There is a wide range of possible applications and many are highly relevant for the water sector. The most well-known is probably the microbial fuel cell, which has been proposed as an environmentally-friendly process for simultaneous wastewater treatment and electrical energy production. However, fullscale implementation at wastewater treatment plants is very challenging and there are several other applications of microbial electrochemistry that are less well-known to people outside the research field, but potentially could be widely applied and make an impact on the water sector in a shorter time perspective. In this paper, we highlight three such applications: (i) sensors for biochemical oxygen demand, volatile fatty acids and toxicity; (ii) in situ bioremediation of contaminated sites; and (iii) removal and recovery of metals from wastewaters, leachates and brines.
|
|
| 22. |
- Molla, Shimelis, et al.
(författare)
-
Extracting metal ions from water with redox active biopolymer electrodes
- 2015
-
Ingår i: Environmental Science. - : ROYAL SOC CHEMISTRY. - 2053-1400 .- 2053-1419. ; 1:3, s. 326-331
-
Tidskriftsartikel (refereegranskat)abstract
- Renewable, environmentally friendly and cheap materials like lignin and cellulose have been considered as promising materials for use in energy storage technologies. Here, we report a new application for biopolymer electrodes where they can also be simultaneously used as ion pumps to purify industrial wastewater and drinking water contaminated with toxic metals. A ternary composite film consisting of a conducting polymer polypyrrole (PPy), biopolymer lignin (LG) and anthraquinonesulfonate (AQS) was synthesized by one-step galvanostatic polymerization from an aqueous electrolyte solution. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) techniques revealed that lead ions can be extracted from a neutral aqueous solution containing lead ions by applying a potential, and can be released into another solution by reversing the polarity of the applied potential. Electrochemical quartz crystal microbalance was used to quantify the amount of metal ions that can be extracted and released.
|
|
| 23. |
- Moona, Nashita, 1985, et al.
(författare)
-
Partial renewal of granular activated carbon filters for improved drinking water treatment
- 2018
-
Ingår i: Environmental Science: Water Research and Technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 4:4, s. 529-538
-
Tidskriftsartikel (refereegranskat)abstract
- There is a trend of increasing natural organic matter (NOM) in raw drinking waters of Nordic countries due to climate change. Seasonal deterioration in NOM quality imparts challenges for delivering a consistently high drinking water quality. In this study, a simple and cost-effective operational strategy was investigated that improved short-term NOM removal in a full-scale treatment plant. Three granular activated carbon (GAC) media biofilters were modified by replacing a small fraction of saturated filter media with new media. Relative to replacing the entire biofilter media, this approach required lower capital cost and shorter downtime and maintained conditions for biological filter functioning. NOM removal efficiencies were compared in modified versus unmodified (reference) filters using online UV absorbance, and offline fluorescence and dissolved organic carbon measurements. The modified biofilters showed improved organic matter removal lasting for at least four weeks. Partial replenishment of GAC in full-scale biofilters may be a useful and sustainable operational strategy for coping with temporarily high NOM loads in raw waters that might otherwise cause water quality problems.
|
|
| 24. |
- Moona, Nashita, 1985, et al.
(författare)
-
Temperature-dependent mechanisms of DOM removal by biological activated carbon filters
- 2019
-
Ingår i: Environmental Science: Water Research and Technology. - : Royal Society of Chemistry (RSC). - 2053-1419 .- 2053-1400. ; 5:12, s. 2232-2241
-
Tidskriftsartikel (refereegranskat)abstract
- Seasonal variability in the removal of dissolved organic matter (DOM) by drinking water biological activated carbon (BAC) filters is often attributed to temperature changes. However, it can be rather difficult to directly relate temperature to treatment efficiency at full scale due to seasonal variations in other influential parameters like DOM concentration and character, and microbial activity. Furthermore, processes in BAC filters include adsorption, desorption and biodegradation within biofilms while each respond differently to temperature. This study aimed to decouple these processes by studying the removal of various DOM fractions from coagulated and settled drinking water when in contact with aged (>3 years) BAC filter material at different water temperatures. DOM removal was measured as changes in dissolved organic carbon (DOC), ultraviolet absorbance at 254 nm (UV254) and fluorescence. Under the particular experimental conditions there was little evidence of biological removal; instead, removal of DOM fractions emitting at longer wavelengths ("humic-like", >430 nm) was consistent with chemisorption, removal of DOM emitting at intermediate wavelengths ("humic-like", 390-420 nm) was consistent with physisorption, and multiple mechanisms were indicated for "protein-like" (<380 nm) DOM. Non-biological mechanisms of DOM removal by aged BAC filters are often assumed to be unimportant; however, these results suggest they are important for some DOM fractions, especially during periods of reduced microbial activity.
|
|
| 25. |
- Munthe, John
(författare)
-
Mitigation options for chemicals of emerging concern in surface waters; Operationalising solutions-focused risk assessment.
- 2017
-
Ingår i: Environmental Science. - 2053-1400 .- 2053-1419. ; 2017
-
Tidskriftsartikel (refereegranskat)abstract
- The water system provides many services to society; industries, municipalities and agriculture all withdraw, use and return water and demand a water quality fit for the intended purposes. Both global production of chemicals and global water withdrawal grow faster than human population. This implies increased chemical threats to water, and creates a strong driver for mitigation to protect human health, ecosystem integrity and ecosystem services. Here we connect the perspectives of the water cycle and the chemical life cycle and review possible mitigation options. We categorize mitigation options in various stages of the chemicals' life cycle, taking various sectors and environmental pathways into account. More technologically oriented versus other types of mitigation options are discerned, and their relevance on spatial and temporal scale is discussed. We review various water treatment techniques in relation to physical–chemical properties of chemicals. Finally we discuss how a mitigation database can be used to assess the effectiveness of interventions, by coupling them to regional or global hydrological models. A solution-focused and systems-oriented perspective combined with a mitigation database offers a common perspective amongst actors on the effects for water quality of possible mitigation options throughout the chemical's life cycle, in various sectors and at various places in the water system. This can stimulate coherent implementation of effective mitigation options, cross-sectoral learning and further innovations to improve water quality.
|
|
| 26. |
- Odhiambo, Michael, 1984, et al.
(författare)
-
Health risks due to intrusion into the drinking water distribution network : hydraulic modelling and quantitative microbial risk assessment
- 2023
-
Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; 9:6, s. 1701-1716
-
Tidskriftsartikel (refereegranskat)abstract
- Ageing water infrastructure is prone to increased physical deficiencies. These form pathways for pathogen intrusion into drinking water distribution networks (WDNs), hence posing major health risks to consumers. This study aimed at estimating the risk of infection from pipe breaks and intermittent water supply, which are some of the major causes of sustained low pressure within the WDN and hence the triggers for pathogen intrusion. Further, the effect of groundwater level on pathogen intrusion was investigated. Three risk scenarios were evaluated on the example of a real WDN in Sweden: (i) pipe break with no intrusion from leak holes, (ii) pipe break with intrusion due to leak holes, and (iii) insufficient water supply in the presence of leak holes. Pressure distribution from hydraulic modelling, estimated groundwater levels, and pathogen concentration in intruding water (from field study) were used to estimate the intrusion and the number of pathogens entering the WDN. Reference pathogens Campylobacter, Cryptosporidium, and norovirus were used in quantitative microbial risk assessment (QMRA) for assessing the health risks. Results indicated that the daily probability of infection exceeded an acceptable target value of 10−6 for most of the WDN and for all scenarios. The findings were consistent with the estimated annual burden of acute gastrointestinal illness in Sweden. The concentration of pathogens in intruding water and the duration of the low-pressure-causing event were observed to influence the probability of infection the most. The results from this study can be used to identify vulnerable sections in the WDN, which can be targeted for additional investment in monitoring and/or renewal.
|
|
| 27. |
- Ottenhall, Anna, 1989-, et al.
(författare)
-
Cellulose-based water purification using paper filters modified with polyelectrolyte multilayers to remove bacteria from water through electrostatic interactions
- 2018
-
Ingår i: Environmental Science. - 2053-1400 .- 2053-1419.
-
Tidskriftsartikel (refereegranskat)abstract
- Filtration is a common way to obtain pure drinking water by removing particles and microorganisms based on size exclusion. Cellulose-based filters are affordable and biobased option for the removal of particles but bacteria are usually too small to be removed by size exclusion alone. In this article, the surfaces of cellulose fibres in two types of commercial paper filters have been given a positive net charge to trap bacteria through electrostatic interactions without releasing any biocides. The fibres were modified with the cationic polyelectrolyte polyvinylamine polymer in single layers (1 L) or in multilayers together with the anionic polyelectrolyte polyacrylic acid (3 L or 5 L) using a water-based process at room temperature. Filtration tests show that all filters, using both types of filter papers and a number of layers, can physically remove more than 99.9% of E. coli from water and that the 3 L modified filters can remove more than 97% of cultivatable bacteria from natural water samples. The bacterial reduction increased with increasing number of filter sheets used for the filtration and the majority of the bacteria were trapped in the top sheets of the filter. The results show the potential for creating water purification filters from bio-based everyday consumable products with a simple modification process. The filters could be used in the future for point-of-use water purification that may be able to save lives without releasing bactericides.
|
|
| 28. |
- Parvage, Mohammed Masud, et al.
(författare)
-
Sequential removal of nitrate and sulfate in woodchip and hematite : coated biochar bioreactor
- 2023
-
Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; 9:2, s. 489-499
-
Tidskriftsartikel (refereegranskat)abstract
- Laboratory column experiments have been used to study the sequential removal of nitrate (NO3−) and sulfate (SO42−) from mine water, where NO3− was removed through denitrification and SO42− was removed through SO42− reduction and the subsequent precipitation of hydrogen sulfide (H2S) in a hematite-coated biochar (HCB) bioreactor. Denitrification and SO42− reduction were investigated in columns filled with pine woodchips and pine woodchips + biochar, both with and without the addition of lactate. Experimental results indicated that a >90% NO3− removal from 50 mg L−1 NO3−-N was achieved at a hydraulic residence time of 5 days without lactate addition, but that SO42− reduction was minimal after an initial startup period. Lactate was added to stimulate SO42− reduction, producing H2S with >90% SO42− removal from an initial concentration of 361 mg L−1 SO42−-S. Sulfate concentrations were reduced to a greater extent in the woodchip + biochar column, and NH4+ production was enhanced in both columns after lactate addition. After treatment in the HCB columns, H2S and NH4+ were removed to >95%. X-ray photoelectron spectroscopy (XPS) indicated that S2−, S22−, S0 and NH4+ were accumulating in the HCB columns and surface-bound iron was converted from Fe(III) to Fe(II). The XPS results suggested that the reductive dissolution of hematite preceded the precipitation of H2S as FeS, pyrite and elemental sulfur on the HCB surfaces.
|
|
| 29. |
|
|
| 30. |
- Regueiro-Picallo, Manuel, et al.
(författare)
-
Combining a daily temperature pattern analysis and a heat-pulse system to estimate sediment depths in sewer systems
- 2024
-
Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; 10:4, s. 922-935
-
Tidskriftsartikel (refereegranskat)abstract
- Sediments in urban drainage systems (UDS) significantly impact their operation, so effective strategies are required to reduce their negative effects. Monitoring sediment accumulation provides valuable insights into sediment characteristics, sediment transport dynamics, and system performance. However, the effectiveness of monitoring systems is limited due to cost constraints and installation challenges. This study describes the development and application of a new system based on temperature dynamics to measure sediment depths in sewer systems. The methodology involves the analysis of temperature time series under dry weather flow conditions to identify harmonic patterns between wastewater and sediment-bed temperatures. These patterns are increasingly attenuated by increasing sediment depth. This study combines a system called MONitoring Temperatures in SEdiments (MONTSE), which integrates a dual-probe heat-pulse (DPHP) method to characterize sediment thermal properties, and a surrogate model, which includes temperature pattern analysis, to estimate sediment depths. Likewise, laboratory-scale experiments were performed to validate the temperature monitoring system and the surrogate model performance. The maximum absolute errors in measured sediment depths were less than 22 mm, and the uncertainty of the system was estimated at ±7.3 mm. Groundbreaking measurements of thermal properties of UDS sediments were also reported. Reliable information on sediment depths and properties was provided, so the system could significantly optimize sewer system operation and cleaning strategies.
|
|
| 31. |
- Ullberg, Malin, et al.
(författare)
-
Pilot-scale removal of organic micropollutants and natural organic matter from drinking water using ozonation followed by granular activated carbon
- 2021
-
Ingår i: Environmental Science: Water Research & Technology. - : Royal Society of Chemistry (RSC). - 2053-1400 .- 2053-1419. ; 7, s. 535-548
-
Tidskriftsartikel (refereegranskat)abstract
- Conventional drinking water treatment is inefficient in removing a large fraction of known organic micropollutants (OMPs). Therefore more efficient treatment approaches are needed to limit exposure to OMPs via drinking water. Here, the OMP removal performance of a combination of ozonation/no ozonation and two types of granular activated carbon (GAC) was tested in a one-year pilot-scale study, alongside a study of full-scale treatment. The raw water was lake water with low ambient concentrations of OMPs. In total, 29 of 99 targeted OMPs (per- and polyfluoroalkyl substances (PFASs), pharmaceuticals and other OMPs) were detected (mean n-ary sumation OMPs = 57 +/- 16 ng L-1). Only a few OMPs were consistently removed in the full-scale process, while ozonation in the pilot experiment effectively removed 72% of detected compounds to levels <30%. The GAC columns showed breakthrough of OMPs and dissolved organic carbon (DOC) for both ozonated and non-ozonated water, with earlier breakthrough for DOC than OMPs. Breakthrough of OMPs was delayed in ozonated columns, possibly because of lower adsorption competition with low-molecular-weight natural organic matter (NOM) fractions measured with liquid chromatography (LC-OCD). The OMP removal performance of the two GAC materials was not affected by greater DOC loading, but Filtrasorb showed 25% higher removal of DOC without losing capacity to remove OMPs. Compounds with low log K-OC tended to break through earlier than those with higher K-OC values. The lowest levels of OMPs were observed in GAC effluents using ozonated feed water demonstrating the efficacy of combining ozone with GAC for managing OMP levels during drinking water production.
|
|
| 32. |
- Vezzaro, Luca, et al.
(författare)
-
Urban stormwater management
- 2023
-
Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; 9:12, s. 3091-3093
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 33. |
- Vidal, Brenda, 1987-, et al.
(författare)
-
Assessing the sustainability of on-site sanitation systems using multi-criteria analysis
- 2019
-
Ingår i: Environmental Science. - Cambridge : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; 5:9, s. 1599-1615
-
Tidskriftsartikel (refereegranskat)abstract
- Small on-site sanitation systems are widely present in suburban and rural areas in many countries. As these systems often underperform and have an impact on receiving waters, understanding their overall sustainability is of interest for policy and decision-makers. However, the definition and estimation of indicators defining sustainability are challenging, as it is finding the methodological approach to combine qualitative and quantitative indicators into one comprehensive assessment. In this study, twelve indicators defined by environmental, economic, social, technical and health-related criteria were used to compare nine alternatives of on-site sanitation for single households. A non-compensatory method for multi-criteria decision analysis, ELECTRE III, was used for the assessment together with weights assigned to each indicator by a reference group. Several scenarios were developed to reflect different goals and a sensitivity analysis was conducted. Overall, the graywater-blackwater separation system resulted as the most sustainable option and, in terms of polishing steps for phosphorus removal, chemical treatment was preferred over the phosphorus filter, both options being implemented together with sand filters. Assessing the robustness of the systems was a crucial step in the analysis given the high importance assigned to the aforementioned indicator by the stakeholders, thus the assessment method must be justified. The proposed multi-criteria approach contributes to aid the assessment of complex information needed in the selection of sustainable sanitation systems and in the provision of informed preferences. © 2019 The Royal Society of Chemistry.
|
|
| 34. |
- Vinnerås, Björn
(författare)
-
Resource recovery technologies as microbial risk barriers: towards safe use of excreta in agriculture based on hazard analysis and critical control point
- 2023
-
Ingår i: Environmental Science: Water Research & Technology. - : Royal Society of Chemistry (RSC). - 2053-1400 .- 2053-1419. ; 9, s. 1008–1029-
-
Tidskriftsartikel (refereegranskat)abstract
- Agricultural use of human excreta contributes to sustainable nutrient resource management. In contrast, resource recovery from human excreta is associated with the risk of infection by pathogenic microorganisms. The microbial risk associated with human excreta needs to be properly managed. Pathogen inactivation efficacy of resource recovery technologies should be evaluated so that individual resource recovery processes can be monitored as health risk barriers. To this end, we reviewed the sanitization potential of resource recovery technologies from human excreta and identified the monitoring parameters of hazard analysis and critical control point (HACCP). We describe the inactivation of surrogate microorganisms in selected technologies in terms of the physicochemical conditions of matrices, different tolerances among surrogate microorganisms, and inactivation mechanisms. The estimated storage/operating time required to achieve the target log reduction values (LRVs) is shortened in thermal processes such as thermophilic storage, drying, composting, microwaving, and thermophilic digestion. In most processes, phage and helminth eggs were found to be appropriate indicators for conservative estimation. Finally, we argue that sanitization is congruent with decomposition of readily degradable organic matter and resource recovery. The barrier efficacy of resource recovery technologies should be validated using a pathogen inactivation kinetics model so that the exposure risk to infectious pathogens is sufficiently reduced through a reasonable combination of non-treatment and non-technical health risk barriers.
|
|
| 35. |
- Yang, Ya, et al.
(författare)
-
Human exposure to phthalate esters via ingestion of municipal drinking water from automatic water purifiers : levels, sources, and risks
- 2022
-
Ingår i: Environmental Science. - : Royal Society of Chemistry. - 2053-1400 .- 2053-1419. ; 8:12, s. 2843-2855
-
Tidskriftsartikel (refereegranskat)abstract
- The presence of organic pollutants in drinking water is an environmental problem threatening public health. Water purifiers are commonly recognized as effective purification equipment for drinking water and are thus prevalent in the market, so there is a need to assess their true effects on drinking water. In this study, we have analyzed the distribution, potential sources, and health risks of phthalate esters (PAEs) in tap as well as purified water. 7 out of 22 target PAEs have been detected in a total of 75 drinking water samples, including tap water (TW), water vending machines (WVMs), and water boiling machines (WBMs). The total concentrations of 22 PAEs are N.D. to 447 ng L-1 in TW samples, 25.7 to 1.10 x 10(3) ng L-1 in WBM water, and N.D. to 841 ng L-1 in WVM water. The concentrations of PAEs in most WVM and WBM samples were comparable or slightly higher than those in TW samples. Meanwhile, the sigma PAE concentrations in the nearshore of the Yangtze Estuary area (northern and southern areas) were slightly higher than those from offshore areas (Pudong: PD, Fengxian and Minhang: FM), which may be attributed to the source water. Combining the results of principal component analysis and correlation analysis, certain PAEs, e.g., diisobutyl phthalate (DIBP), dibuthyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), were more polluting than diethyl phthalate (DEP) and di-methyl phthalate (DMP) in WVM water than those in TW samples. This work suggests that the application of water purifiers may not remove certain PAEs efficiently from drinking water. In addition, the estimated daily intakes (EDIs) of sigma PAE via drinking water from automatic water purifiers were 2-3 times those from tap water under a high-exposure scenario, but all EDIs are well below current health regulatory guidelines for PAEs. This survey indicates that water purifiers made nearly no decrease to the PAE concentrations and possibly have negative effects on the quality of drinking water.
|
|
| 36. |
- Cascone, Claudia, et al.
(författare)
-
AbspectroscoPY, a Python toolbox for absorbance-based sensor data in water quality monitoring
- 2022
-
Ingår i: Environmental Science: Water Research & Technology. - 2053-1419. ; 8:4, s. 836-848
-
Tidskriftsartikel (refereegranskat)abstract
- The long-term trend of increasing natural organic matter (NOM) in boreal and north European surface waters represents an economic and environmental challenge for drinking water treatment plants (DWTPs). High-frequency measurements from absorbance-based online spectrophotometers are often used in modern DWTPs to measure the chromophoric fraction of dissolved organic matter (CDOM) over time. These data contain valuable information that can be used to optimise NOM removal at various stages of treatment and/or diagnose the causes of underperformance at the DWTP. However, automated monitoring systems generate large datasets that need careful preprocessing, followed by variable selection and signal processing before interpretation. In this work we introduce AbspectroscoPY (“Absorbance spectroscopic analysis inPython”), a Python toolbox for processing time-series datasets collected by in situ spectrophotometers. The toolbox addresses some of the main challenges in data preprocessing by handling duplicates, systematic time shifts, baseline corrections and outliers. It contains automated functions to compute a range of spectral metrics for the time-series data, including absorbance ratios, exponential fits, slope ratios and spectral slope curves. To demonstrate its utility, AbspectroscoPY was applied to 15-month datasets from three onlinespectrophotometers in a drinking water treatment plant. Despite only small variations in surface water quality over the time period, variability in the spectrophotometric profiles of treated water could be identified, quantified and related to lake turnover or operational changes in the DWTP. This toolboxrepresents a step toward automated early warning systems for detecting and responding to potential threats to treatment performance caused by rapid changes in incoming water quality.
|
|
| 37. |
- Ekholm, Jennifer, et al.
(författare)
-
Full-scale aerobic granular sludge for municipal wastewater treatment – granule formation, microbial succession, and process performance
- 2022
-
Ingår i: Environmental Science: Water Research & Technology. - 2053-1419. ; :8, s. 3138-3154
-
Tidskriftsartikel (refereegranskat)abstract
- Aerobic granular sludge (AGS) plants have gained growing interest and application due to their low energy demand, small footprint, and low operational costs. However, the fulfilment of strict discharge limits for nitrogen and phosphorus, vast seasonal temperature variations, and large peaks in influent flows may pose challenges to the implementation of AGS. Moreover, the knowledge about microbial community assembly and process performance under varying environmental conditions in full-scale reactors is still limited. In this study, the first implementation of the AGS process in the Nordic countries was assessed. In two full-scale AGS reactors with different seeding sludges, the start-up was associated with rapid changes in microbial community composition in both, but only successful granulation in one. As a consequence, the non-granulated reactor was eventually reseeded with biomass from the better granulated reactor. This resulted in a convergence of the microbial communities in the two reactors with the maintenance of stable sludge concentrations (6–8 g L−1) with large granules (50–80% with diameter >2 mm) and fast settling of biomass (SVI30/SVI10 of 0.9–1). Immigration from the influent wastewater was a minor factor affecting the microbial community once the granules had formed, while the seasonal variations in environmental factors were identified as important. Key guilds of AOB (Nitrosomonas), NOB (mainly Ca. Nitrotoga), PAOs (mainly Tetrasphaera), and GAOs (mainly Ca. Competibacter) varied considerably in abundance throughout the study period. After 15 months, stable organic matter, nitrogen, and phosphorus removal were attained with low effluent concentrations. During the start-up, the BOD7/N ratio, influent flow, and temperature were important factors influencing the performance of the AGS.
|
|
| 38. |
- Pullerits, Kristjan, et al.
(författare)
-
Impact of coagulation–ultrafiltration on long-term pipe biofilm dynamics in a full-scale chloraminated drinking water distribution system
- 2020
-
Ingår i: Environmental Science: Water Research & Technology. - 2053-1419. ; 6:11, s. 3044-3056
-
Tidskriftsartikel (refereegranskat)abstract
- While pipe biofilms in DWDSs (drinking water distribution systems) are thought to affect the quality of distributed water, studies regarding the microbial processes are impeded by the difficulties in accessing biofilm undisturbed by DWDS maintenance. In this study, pipe sections were removed from a fully operational DWDS for biofilm sampling over two years and three months, and before and after start of ultrafiltration (UF) with coagulation treatment in the drinking water treatment plant (DWTP). Water (n = 31), surface biofilm (obtained by swabbing, n = 34) and deep pipe biofilm (obtained by scraping, n = 34) were analyzed with 16S rRNA gene amplicon sequencing; with flow cytometry, and chemical and natural organic matter (NOM) analysis as additional parameters for water quality. UF with coagulation decreased the total cell concentration in the DWDS bulk water from 6.0 × 105 ± 2.3 × 105 cells per ml to 6.0 × 103 ± 8.3 × 103 cells per ml, including fluctuations due to seasonal change, as well as decreasing most analyzed fractions of NOM. UF treatment of the water revealed that 75% ± 18% of the cells in the water originated from DWDS biofilm, confirmed by SourceTracker analysis, with the rest of the cells likely released from biofilm on DWTP storage tanks. Following UF start, the ASVs (amplicon sequence variants) in the deep pipe biofilm decreased, and Evenness and Shannon diversity indices decreased, reflecting the community's response to the new environment created by the altered water quality. The pipe biofilm community was dominated by ASVs classified as Nitrosomonadaceae, Nitrospira, Hyphomicrobium and Sphingomonas, with relative abundances ranging from 5–78%, and also included ASVs of genus Mycobacterium, genus Legionella and order Legionellales. This community composition, together with the observation that turnover of nitrogen compounds was unchanged by UF start, indicate that nitrification in the DWDS was localized to the pipe biofilm.
|
|
