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Baoyou Shi - One of the best experts on this subject based on the ideXlab platform.
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Occurrence and transport behaviors of perfluoroalkyl acids in drinking water distribution systems
The Science of the total environment, 2019Co-Authors: Ruya Chen, Yuan Zhuang, Hui Tao, Baoyou ShiAbstract:Abstract Although human exposure to perfluoroalkyl acids (PFAAs) through tap water is an ongoing concern, knowledge of the PFAAs occurrence in the tap water and the associated transport behaviors of PFAAs in drinking water distribution systems (DWDSs) are scarce. This investigation profiled the occurrence of 17 kinds of PFAAs in tap water of some Chinese cities, and the transport behaviors of PFAAs in DWDS were observed in eastern China. Tap water samples both along trunk pipelines and at the distal ends were collected to display the PFAAs occurrence scenarios. Loose deposit solids were also obtained to reveal their possible accumulation effect on PFAAs. The results showed that perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA) widely existed in tap water samples, and were the predominant PFAAs in eastern China areas. The mean concentration of the 17 PFAAs was 77.49 ng/L (ranging from 9.29 ng/L to 266.68 ng/L). Short-chain PFAAs (mainly PFBA) concentrations were relatively stable from water treatment plant to consumer taps, while long-chain PFAAs (mainly PFOA) exhibited a significant decrease in concentration, which could be attributed to their accumulation by the loose deposits in the DWDSs. It was calculated that PFOA has a higher partition coefficient than PFBA; this means that the former has a stronger potential to be adsorbed by loose deposits. In addition, the accumulation ability of loose deposits might be associated with the composition of Al, Fe and Si in the loose deposits. The positive correlation between the short-chain PFAAs and dissolved organic carbon (DOC) indicated the possible interactions between PFAA and natural organic matter could favor short-chain PFAAs to retain in bulk water. When water quality conditions change or Hydraulic Disturbance occur, loose deposits may enter tap water bringing accumulated PFAAs with it, which may result in potential health risks.
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The occurrence and transformation behaviors of disinfection byproducts in drinking water distribution systems in rural areas of eastern China.
Chemosphere, 2019Co-Authors: Ruya Chen, Hui Tao, Baoyou ShiAbstract:Abstract The occurrence and transformation behaviors of disinfection byproducts (DBPs) were investigated in the finished water and tap water of 14 water treatment plants in rural areas of eastern China. Mammalian cell toxicity data from previous studies were used to evaluate the cytotoxicity of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), trichloronitromethane (TCNM) and the genotoxicity of HAAs, HANs and TCNM. Correlation analysis was conducted to identify the factors that might influence the variability of DBPs. The measured median values were 29.76 μg/L for THMs, 20.47 μg/L for HAAs, 3.98 μg/L for HANs, 0.76 μg/L for haloketones (HKs) and 0.03 μg/L for TCNM. The spatial variability analysis showed that the total concentrations of HAAs and HANs decreased during long Hydraulic residence time (HRT) in seven drinking water distribution systems, which could result in reduced mammalian cell cytotoxicity and genotoxicity at consumers’ taps. The concentrations of trihalogenated-DBPs were more stable than those of dihalogenated-DBPs and monohalogenated-DBPs during long HRT. Bromine acted as a more efficient substituting agent than chlorine for THMs and dihaloacetonitriles (DHANs) in actual drinking water. The dominant chlorinated-THMs and chlorinated-DHANs would transfer to brominated -THMs and brominated-DHANs when the concentration of bromide ion exceeds 450.67 and 610.25 μg/L, respectively. Correlation analysis indicated that particulate and soluble manganese (Mn) might play critical roles in promoting the production of DBPs in bulk water. Hydraulic Disturbance could also result in secondary release of DBPs from loose deposits accumulated on distribution pipe walls.
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Practical evaluation of inorganic contaminant presence in a drinking water distribution system after Hydraulic Disturbance
Journal of Water Supply: Research and Technology - Aqua, 2017Co-Authors: Bingjun Han, Ruya Chen, Baoyou Shi, Yuan ZhuangAbstract:The accumulation of loose deposits in a drinking water distribution system (DWDS) is a potential risk for water quality. In this work, Hydraulic Disturbance was simulated in different areas of a large DWDS. The water quality features before and after the Disturbance were compared, and the solid deposits captured from different experimental sites were characterized. The results showed that the Hydraulic Disturbance increased the water turbidity and color, which can be attributed to the re-suspension of iron and manganese oxide particulates. The concentrations of arsenic and lead increased after the Disturbance, and a significant positive correlation was observed between the iron and arsenic concentrations. The solid deposits exhibited distinct characteristics in different sites based on the normal Hydraulic conditions and pipe material. The main crystalline iron substances were goethite and pyrosiderite. The iron and arsenic contents in the deposits had a positive correlation with their concentrations in the disturbed water. The combination status of manganese, chromium, and lead in the deposits was different from that of arsenic.
Martin T Pusch - One of the best experts on this subject based on the ideXlab platform.
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resistance to ship induced waves of benthic invertebrates in various littoral habitats
Freshwater Biology, 2008Co-Authors: Friederike Gabel, Xavierfrancois Garcia, Mario Brauns, Alexander Sukhodolov, M Leszinski, Martin T PuschAbstract:Summary 1. Ship-induced waves disturb benthic invertebrate assemblages colonizing littoral zones of lakes and rivers. However, the impact of ship-induced waves on invertebrates has rarely been quantified, and the influencing factors have not been addressed. 2. In an experimental wave tank, five benthic invertebrate species, Bithynia tentaculata, Calopteryx splendens, Dikerogammarus villosus, Gammarus roeseli and Laccophilus hyalinus, were exposed to waves of increasing shear stress (0.43–2.19 N m−2). Mean number of detached individuals was recorded for five littoral habitats [coarse woody debris (CWD), reeds, sand, stones and tree roots], representing different levels of structural complexity as quantified by their fractal dimensions (FD). 3. Results showed that detachment of invertebrates was significantly related to shear stress in all habitats except tree roots. Detachments averaged for the five species were significantly lower in habitats with a high degree of structural complexity, decreasing in the habitat sequence: sand, CWD, stones, reeds and tree roots. 4. Consistent with their different morphologies and methods of attachment to substrates, the five species displayed differences in their response to Hydraulic stress that were dependent on habitat. 5. The increasing sheltering effect of structural habitat complexity was mirrored by increasing dissipation of the kinetic energy of waves; i.e. the FD of the habitat was positively correlated with shear stress reduction due to the flow resistance of the habitat. 6. Network habitats such as tree roots provided the best sheltering conditions against Hydraulic Disturbance, because they combined good refuge availability for all studied invertebrate species and maximal dissipation of kinetic wave energy. Consequently, persistent anthropogenic impacts, such as lakeshore modification or long-term exposure to ship-induced waves, which cause disappearance of complex littoral habitats such as tree roots or dense reed belts, will drastically increase the adverse effects of boating and ship traffic on littoral invertebrate assemblages.
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Resistance to ship‐induced waves of benthic invertebrates in various littoral habitats
Freshwater Biology, 2008Co-Authors: Friederike Gabel, Xavierfrancois Garcia, Mario Brauns, Alexander Sukhodolov, M Leszinski, Martin T PuschAbstract:Summary 1. Ship-induced waves disturb benthic invertebrate assemblages colonizing littoral zones of lakes and rivers. However, the impact of ship-induced waves on invertebrates has rarely been quantified, and the influencing factors have not been addressed. 2. In an experimental wave tank, five benthic invertebrate species, Bithynia tentaculata, Calopteryx splendens, Dikerogammarus villosus, Gammarus roeseli and Laccophilus hyalinus, were exposed to waves of increasing shear stress (0.43–2.19 N m−2). Mean number of detached individuals was recorded for five littoral habitats [coarse woody debris (CWD), reeds, sand, stones and tree roots], representing different levels of structural complexity as quantified by their fractal dimensions (FD). 3. Results showed that detachment of invertebrates was significantly related to shear stress in all habitats except tree roots. Detachments averaged for the five species were significantly lower in habitats with a high degree of structural complexity, decreasing in the habitat sequence: sand, CWD, stones, reeds and tree roots. 4. Consistent with their different morphologies and methods of attachment to substrates, the five species displayed differences in their response to Hydraulic stress that were dependent on habitat. 5. The increasing sheltering effect of structural habitat complexity was mirrored by increasing dissipation of the kinetic energy of waves; i.e. the FD of the habitat was positively correlated with shear stress reduction due to the flow resistance of the habitat. 6. Network habitats such as tree roots provided the best sheltering conditions against Hydraulic Disturbance, because they combined good refuge availability for all studied invertebrate species and maximal dissipation of kinetic wave energy. Consequently, persistent anthropogenic impacts, such as lakeshore modification or long-term exposure to ship-induced waves, which cause disappearance of complex littoral habitats such as tree roots or dense reed belts, will drastically increase the adverse effects of boating and ship traffic on littoral invertebrate assemblages.
Jill Lancaster - One of the best experts on this subject based on the ideXlab platform.
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Field experiments on flow refugia in streams
Freshwater Biology, 1997Co-Authors: Julie Winterbottom, Stuart Orton, Alan G. Hildrew, Jill LancasterAbstract:1. Field experiments were carried out to determine whether animals move into areas of low shear stress during periods of peak flow and therefore avoid Hydraulic Disturbance. 2. Flow at the scale of 0.05 m2 patches was reduced experimentally by creating artificial ‘refugia’. Invertebrate colonization of cages with 1.1 mm mesh sides, which provided such potential refugia by reducing Hydraulic forces within the cage, was compared with colonization of cages with coarser (15 mm) mesh which did not restrict the flow. 3. Colonization of these cages was tested over a series of weekly periods in two different streams. Nine trials were completed in a stream with abundant natural flow refugia (Broadstone Stream, SE England), and during three of these trials strong spates occurred. Six trials were completed in a stream with comparatively few natural flow refugia (Dargall Lane, SW Scotland), and peak flows were relatively less. 4. In Broadstone Stream, the relative colonization of refugium cages was greatest during periods of peak flow, suggesting animals had used these low-flow areas as refugia during spates. Use of the artificial refugia did not occur in Dargall Lane, at least at the flows achieved during the trials. 5. Our results are consistent with the hypothesis that stream invertebrates accumulate in refugia during high flow Disturbances. Whether their distribution among patches is altered by active or passive means remains unclear.
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Scaling the effects of predation and Disturbance in a patchy environment
Oecologia, 1996Co-Authors: Jill LancasterAbstract:The effects of Hydraulic Disturbances on the impact of two predatory benthic invertebrates on their prey were examined in a stream at two distinct spatial scales. At the scale of small habitat patches (0.0625 m^2), Hydraulic patch type was an important determinant of the microdistribution of prey and predators. Prey abundances were similar across all patch types at baseflow, but local densities were higher in patches identified as low-flow refugia after periods of high and fluctuating flow. The microdistribution pattern of predatory larvae of a caddisfly, Plectrocnemia conspersa , was similar to that of its prey, whereas predatory larvae of an alderfly, Sialis fuliginosa , did not shift their microdistribution significantly with discharge and were always most abundant in lowflow refugia. There was little evidence of an aggregative response of predators with prey, even though both predators and prey are mobile. Both predator species showed similar patch-specific patterns of per capita consumption rates: uniform consumption rates across Hydraulic patch types at low and moderate flows, but highest in flow refugia during high flows. Species-specific patterns, however, were apparent in the magnitude and direction of differences between consumption rates during Disturbance events, and in comparable patches at base flow: At high flow, consumption rates for P. conspersa were exaggerated (3.9 times higher) in flow refugia but “at par” in other patches; for S. fuliginosa they were “at par” in flow refugia but reduced in other patches (up to 3.3. times lower). These differences may be related to species-specific foraging behaviours (search vs ambush predators) and the influence of prey movements on feeding success. Using the patch-scale results only, it is difficult to predict the effects of physical Disturbance on predation intensity at the larger scales of whole habitats, populations or communities. At the large scale (>200 m^2), net predator impacts were estimated over the stream reach, using a spatially explicit model that accounts, in an additive way, for habitat heterogeneity and patch-specific responses of predators and prey. The relationship between predator impact over the whole reach and Hydraulic Disturbance differed for the two predators. The predator impact of S. fuliginosa decreased with increasing Hydraulic Disturbance, as predicted by the harsh-benign hypothesis. There was no directional trend for P. conspersa , however, and maximum predator impact may occur at intermediate Disturbance levels. For the prey community in this stream, predation pressure from S. fuliginosa appears to fluctuate directly with the discharge hydrograph, whereas predation from P. conspersa may be more persistent. Flow refugia may play a dual role in the sructure of stream communities by preventing catastrophic mortality of animals (predators and prey) from physical forces during Disturbances, and by maintaining (or perhaps increasing) predation pressure. Summing the effects of species interactions in small habitat patches to the larger scale of a whole stream reach indicates that the scale of approach influences the observed patterns and their implied underlying process.
Ruya Chen - One of the best experts on this subject based on the ideXlab platform.
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Occurrence and transport behaviors of perfluoroalkyl acids in drinking water distribution systems
The Science of the total environment, 2019Co-Authors: Ruya Chen, Yuan Zhuang, Hui Tao, Baoyou ShiAbstract:Abstract Although human exposure to perfluoroalkyl acids (PFAAs) through tap water is an ongoing concern, knowledge of the PFAAs occurrence in the tap water and the associated transport behaviors of PFAAs in drinking water distribution systems (DWDSs) are scarce. This investigation profiled the occurrence of 17 kinds of PFAAs in tap water of some Chinese cities, and the transport behaviors of PFAAs in DWDS were observed in eastern China. Tap water samples both along trunk pipelines and at the distal ends were collected to display the PFAAs occurrence scenarios. Loose deposit solids were also obtained to reveal their possible accumulation effect on PFAAs. The results showed that perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA) widely existed in tap water samples, and were the predominant PFAAs in eastern China areas. The mean concentration of the 17 PFAAs was 77.49 ng/L (ranging from 9.29 ng/L to 266.68 ng/L). Short-chain PFAAs (mainly PFBA) concentrations were relatively stable from water treatment plant to consumer taps, while long-chain PFAAs (mainly PFOA) exhibited a significant decrease in concentration, which could be attributed to their accumulation by the loose deposits in the DWDSs. It was calculated that PFOA has a higher partition coefficient than PFBA; this means that the former has a stronger potential to be adsorbed by loose deposits. In addition, the accumulation ability of loose deposits might be associated with the composition of Al, Fe and Si in the loose deposits. The positive correlation between the short-chain PFAAs and dissolved organic carbon (DOC) indicated the possible interactions between PFAA and natural organic matter could favor short-chain PFAAs to retain in bulk water. When water quality conditions change or Hydraulic Disturbance occur, loose deposits may enter tap water bringing accumulated PFAAs with it, which may result in potential health risks.
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The occurrence and transformation behaviors of disinfection byproducts in drinking water distribution systems in rural areas of eastern China.
Chemosphere, 2019Co-Authors: Ruya Chen, Hui Tao, Baoyou ShiAbstract:Abstract The occurrence and transformation behaviors of disinfection byproducts (DBPs) were investigated in the finished water and tap water of 14 water treatment plants in rural areas of eastern China. Mammalian cell toxicity data from previous studies were used to evaluate the cytotoxicity of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), trichloronitromethane (TCNM) and the genotoxicity of HAAs, HANs and TCNM. Correlation analysis was conducted to identify the factors that might influence the variability of DBPs. The measured median values were 29.76 μg/L for THMs, 20.47 μg/L for HAAs, 3.98 μg/L for HANs, 0.76 μg/L for haloketones (HKs) and 0.03 μg/L for TCNM. The spatial variability analysis showed that the total concentrations of HAAs and HANs decreased during long Hydraulic residence time (HRT) in seven drinking water distribution systems, which could result in reduced mammalian cell cytotoxicity and genotoxicity at consumers’ taps. The concentrations of trihalogenated-DBPs were more stable than those of dihalogenated-DBPs and monohalogenated-DBPs during long HRT. Bromine acted as a more efficient substituting agent than chlorine for THMs and dihaloacetonitriles (DHANs) in actual drinking water. The dominant chlorinated-THMs and chlorinated-DHANs would transfer to brominated -THMs and brominated-DHANs when the concentration of bromide ion exceeds 450.67 and 610.25 μg/L, respectively. Correlation analysis indicated that particulate and soluble manganese (Mn) might play critical roles in promoting the production of DBPs in bulk water. Hydraulic Disturbance could also result in secondary release of DBPs from loose deposits accumulated on distribution pipe walls.
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Practical evaluation of inorganic contaminant presence in a drinking water distribution system after Hydraulic Disturbance
Journal of Water Supply: Research and Technology - Aqua, 2017Co-Authors: Bingjun Han, Ruya Chen, Baoyou Shi, Yuan ZhuangAbstract:The accumulation of loose deposits in a drinking water distribution system (DWDS) is a potential risk for water quality. In this work, Hydraulic Disturbance was simulated in different areas of a large DWDS. The water quality features before and after the Disturbance were compared, and the solid deposits captured from different experimental sites were characterized. The results showed that the Hydraulic Disturbance increased the water turbidity and color, which can be attributed to the re-suspension of iron and manganese oxide particulates. The concentrations of arsenic and lead increased after the Disturbance, and a significant positive correlation was observed between the iron and arsenic concentrations. The solid deposits exhibited distinct characteristics in different sites based on the normal Hydraulic conditions and pipe material. The main crystalline iron substances were goethite and pyrosiderite. The iron and arsenic contents in the deposits had a positive correlation with their concentrations in the disturbed water. The combination status of manganese, chromium, and lead in the deposits was different from that of arsenic.
Friederike Gabel - One of the best experts on this subject based on the ideXlab platform.
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resistance to ship induced waves of benthic invertebrates in various littoral habitats
Freshwater Biology, 2008Co-Authors: Friederike Gabel, Xavierfrancois Garcia, Mario Brauns, Alexander Sukhodolov, M Leszinski, Martin T PuschAbstract:Summary 1. Ship-induced waves disturb benthic invertebrate assemblages colonizing littoral zones of lakes and rivers. However, the impact of ship-induced waves on invertebrates has rarely been quantified, and the influencing factors have not been addressed. 2. In an experimental wave tank, five benthic invertebrate species, Bithynia tentaculata, Calopteryx splendens, Dikerogammarus villosus, Gammarus roeseli and Laccophilus hyalinus, were exposed to waves of increasing shear stress (0.43–2.19 N m−2). Mean number of detached individuals was recorded for five littoral habitats [coarse woody debris (CWD), reeds, sand, stones and tree roots], representing different levels of structural complexity as quantified by their fractal dimensions (FD). 3. Results showed that detachment of invertebrates was significantly related to shear stress in all habitats except tree roots. Detachments averaged for the five species were significantly lower in habitats with a high degree of structural complexity, decreasing in the habitat sequence: sand, CWD, stones, reeds and tree roots. 4. Consistent with their different morphologies and methods of attachment to substrates, the five species displayed differences in their response to Hydraulic stress that were dependent on habitat. 5. The increasing sheltering effect of structural habitat complexity was mirrored by increasing dissipation of the kinetic energy of waves; i.e. the FD of the habitat was positively correlated with shear stress reduction due to the flow resistance of the habitat. 6. Network habitats such as tree roots provided the best sheltering conditions against Hydraulic Disturbance, because they combined good refuge availability for all studied invertebrate species and maximal dissipation of kinetic wave energy. Consequently, persistent anthropogenic impacts, such as lakeshore modification or long-term exposure to ship-induced waves, which cause disappearance of complex littoral habitats such as tree roots or dense reed belts, will drastically increase the adverse effects of boating and ship traffic on littoral invertebrate assemblages.
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Resistance to ship‐induced waves of benthic invertebrates in various littoral habitats
Freshwater Biology, 2008Co-Authors: Friederike Gabel, Xavierfrancois Garcia, Mario Brauns, Alexander Sukhodolov, M Leszinski, Martin T PuschAbstract:Summary 1. Ship-induced waves disturb benthic invertebrate assemblages colonizing littoral zones of lakes and rivers. However, the impact of ship-induced waves on invertebrates has rarely been quantified, and the influencing factors have not been addressed. 2. In an experimental wave tank, five benthic invertebrate species, Bithynia tentaculata, Calopteryx splendens, Dikerogammarus villosus, Gammarus roeseli and Laccophilus hyalinus, were exposed to waves of increasing shear stress (0.43–2.19 N m−2). Mean number of detached individuals was recorded for five littoral habitats [coarse woody debris (CWD), reeds, sand, stones and tree roots], representing different levels of structural complexity as quantified by their fractal dimensions (FD). 3. Results showed that detachment of invertebrates was significantly related to shear stress in all habitats except tree roots. Detachments averaged for the five species were significantly lower in habitats with a high degree of structural complexity, decreasing in the habitat sequence: sand, CWD, stones, reeds and tree roots. 4. Consistent with their different morphologies and methods of attachment to substrates, the five species displayed differences in their response to Hydraulic stress that were dependent on habitat. 5. The increasing sheltering effect of structural habitat complexity was mirrored by increasing dissipation of the kinetic energy of waves; i.e. the FD of the habitat was positively correlated with shear stress reduction due to the flow resistance of the habitat. 6. Network habitats such as tree roots provided the best sheltering conditions against Hydraulic Disturbance, because they combined good refuge availability for all studied invertebrate species and maximal dissipation of kinetic wave energy. Consequently, persistent anthropogenic impacts, such as lakeshore modification or long-term exposure to ship-induced waves, which cause disappearance of complex littoral habitats such as tree roots or dense reed belts, will drastically increase the adverse effects of boating and ship traffic on littoral invertebrate assemblages.
