Статті в журналах: "Dissolved and particulate phases"

1

Wei, Zhang, Li Simin, and Tang Fengbing. "Characterization of Urban Runoff Pollution between Dissolved and Particulate Phases." Scientific World Journal 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/964737.

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To develop urban stormwater management effectively, characterization of urban runoff pollution between dissolved and particulate phases was studied by 12 rainfall events monitored for five typical urban catchments. The average event mean concentration (AEMC) of runoff pollutants in different phases was evaluated. The AEMC values of runoff pollutants in different phases from urban roads were higher than the ones from urban roofs. The proportions of total dissolved solids, total dissolved nitrogen, and total dissolved phosphorus in total ones for all the catchments were 26.19%–30.91%, 83.29%–90.51%, and 61.54–68.09%, respectively. During rainfall events, the pollutant concentration at the initial stage of rainfall was high and then sharply decreased to a low value. Affected by catchments characterization and rainfall distribution, the highest concentration of road pollutants might appear in the later period of rainfall. Strong correlations were also found among runoffs pollutants in different phases. Total suspended solid could be considered as a surrogate for particulate matters in both road and roof runoff, while dissolved chemical oxygen demand could be regarded as a surrogate for dissolved matters in roof runoff.

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2

Pierce, Emily F., and Astrid Schnetzer. "Microcystin Concentrations, Partitioning, and Structural Composition during Active Growth and Decline: A Laboratory Study." Toxins 15, no. 12 (December 6, 2023): 684. http://dx.doi.org/10.3390/toxins15120684.

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Microcystin can be present in variable concentrations, phases (dissolved and particulate), and structural forms (congeners), all which impact the toxicity and persistence of the algal metabolite. Conducting incubation experiments with six bloom assemblages collected from the Chowan River, North Carolina, we assessed microcystin dynamics during active growth and biomass degradation. Upon collection, average particulate and dissolved microcystin ranged between 0.2 and 993 µg L−1 and 0.5 and 3.6 µg L−1, respectively. The presence of congeners MC-LA, -LR, -RR, and -YR was confirmed with MC-RR and MC-LR being the most prevalent. Congener composition shifted over time and varied between dissolved and particulate phases. Particulate microcystin exponentially declined in five of six incubations with an average half-life of 10.2 ± 3.7 days, while dissolved microcystin remained detectable until the end of the incubation trials (up to 100 days). Our findings suggest that concerns about food-web transfer via intracellular toxins seem most warranted within the first few weeks of the bloom peak, while dissolved toxins linger for several months in the aftermath of the event. Also, it was indicated there were differences in congener profiles linked to the sampling method. We believe this study can inform monitoring strategies and aid microcystin-exposure risk assessments for cyanobacterial blooms.

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3

Zhou, Jun L., Steve Rowland, and R. Fauzi C. Mantoura. "Partition of synthetic pyrethroid insecticides between dissolved and particulate phases." Water Research 29, no. 4 (April 1995): 1023–31. http://dx.doi.org/10.1016/0043-1354(94)00240-8.

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4

Journal, Baghdad Science. "Distribution Of Some Heavy Metals In Water,Sediment & Fish Cyprinus carpio in Euphrates River Near Al- Nassiriya City Center South Iraq ." Baghdad Science Journal 8, no. 1 (March 13, 2011): 552–60. http://dx.doi.org/10.21123/bsj.8.1.552-560.

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The heavy metals Cd, Cu, Fe, pb, and Zn were determined in dissolved and particulate phases of the water,in addition to exchangeable and residual phases of the sediment and in the selected organs of the fish Cyprinus carpio collected from the Euphrates River near Al-Nassiriya city center south of Iraq during the summer period / 2009 .Also sediment texture and total organic carbon(TOC) were measured. Analysis emploing a flam Atomic Absorption Spectrophotometers . The mean regional concentrations of the heavy metals in dissolved (µg/l) and particulate phases (µg/gm) dry weight were Cd (0.15,16.13) ,Cu (0.59,24.48) ,Fe (726,909.4) ,Pb (0.20, 49.95) and Zn (2.5,35.62) respectively,and those for exchangeable and residual phases of the Sediment were Cd (0.2,0.1) ,Cu (13.75,16.65) ,Fe (683 , 1351 ) ,Pb (10.1,1.07) and Zn (7.3,16.75)µg/gm dry weight respectively. The heavy metals concentrations in C. carpio organs followed the trend gill > liver > kidney> muscles . The mean concentration in the muscles were Cd (ND) , Cu (0.07) , Fe (4.7) , pb (0.06) and Zn (6.4) (µg/gm) dry weight . The statistical analysis proved a significant correlation between metal concentration in the sediment and total organic carbon, also a positive correlation was proved between its concentrations in the liver organ and the water (particulate phase) . In conclusion the trace metals concentration in particulate phase were higher than its concentration in the dissolved phase . The fish organs showed variations in the metals concentration and the muscle organs showed less concentration than the other organs .

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5

Yeats, P. A., and D. H. Loring. "Dissolved and particulate metal distributions in the St. Lawrence estuary." Canadian Journal of Earth Sciences 28, no. 5 (May 1, 1991): 729–42. http://dx.doi.org/10.1139/e91-063.

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Dissolved and particulate metal concentrations in the St. Lawrence estuary were determined during the high spring runoff and at a period of lower runoff in the fall. The distributions in the estuary are influenced by seasonally variable freshwater discharges and a turbidity maximum zone (TMZ). Dissolved Al, Fe, Mn, Co, Cu, Ni, and Zn concentrations generally decrease significantly with increasing salinity, but Cd shows no significant covarience with salinity. Most metals show complex distribution patterns, and only the distributions of Cu and Ni can be described by linear regression equations. Maximum concentrations of dissolved Al, Fe, Mn, and Co occur in the turbidity maximum and decrease seaward with increasing salinity. During the spring runoff period, total particulate mass was almost twice that in the lower fall runoff period. Chemical partition of the suspended particulate matter (SPM) shows that detrital particulate Fe, Mn, and Zn concentrations vary directly with SPM load and inversely with salinity. Nondetrital metal concentrations vary inversely with SPM (Mg, Pb, Cd) and salinity (Al, Fe, Mn, Zn, Cu). Such changes are not evident in the particulate composition during the low-runoff sampling period. Factor analyses imply that fine-grained aluminosilicates are the main carriers of detrital Si, Al, Ca, Cu, Fe, Mn, and Zn. Nondetrital Al, Cu, Fe, Mn, Pb, and Zn appear to be held in ion-exchange positions, and Fe–Mn grain coatings during the period of high spring runoff and for the fall data set (Cd, Fe, Al, and Pb only). Nondetrital Ca appears to carried by carbonates in the spring data set and along with mixed Ca–Mg carbonates in the fall data set. During high and low river-flow periods, riverine particulate inputs predominate and control the overall abundance, dispersal, and composition of the particulates. Data analyses indicate that, within the TMZ, internal particle cycling and resuspension combined with adsorption–desorption processes override some of the riverine effects and control or modify the particulate composition. Model calculations suggest that dissolved – nondetrital particulate metal exchanges can account for some but not all of the observed changes in the distribution of the dissolved and nondetrital phases.

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6

Hassan, Fikrat M., Maysoon M. Saleh, and Jasim M. Salman. "A Study of Physicochemical Parameters and Nine Heavy Metals in the Euphrates River, Iraq." E-Journal of Chemistry 7, no. 3 (2010): 685–92. http://dx.doi.org/10.1155/2010/906837.

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This study was conducted to reveal possible environmental effects on the Euphrates River from the Al-Hindiya barrage to the downstream end of Al-Kufa city in the middle of Iraq. Seven sites were selected along the study area and sampled during March 2004 to February 2005. We measured physical and chemical properties (air and water temperature, pH, electrical conductivity, TDS, TSS and dissolved oxygen) as well as, concentration and distribution of some heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in both dissolved and particulate phases, in the water and sediments (exchangeable and residual phases). The studied area was slightly alkaline, with very hard water and high BOD5. The nutrients showed clear seasonal fluctuations in their concentrations. It was shown that the concentrations of metals in the particulate phase were higher than those in dissolved phase in water. In sediments, the mean concentrations of heavy metals as exchangeable phase were less than in the residual phase.

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7

Morris, A. W., A. J. Bale, R. J. M. Howland, G. E. Millward, D. R. Ackroyd, D. H. Loring, and R. T. T. Rantala. "Sediment Mobility and its Contribution to Trace Metal Cycling and Retention in a Macrotidal Estuary." Water Science and Technology 18, no. 4-5 (April 1, 1986): 111–19. http://dx.doi.org/10.2166/wst.1986.0186.

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Measurements of trace metals in the dissolved, suspended particulate and sediment phases of the Tamar Estuary have been combined with observations of sediment and suspended particle mobility in an interpretation of metal cycling and retention processes within the system. Dissolved metal distributions indicate pronounced estuarine metal reactivity involving net removal onto suspended particles in the low salinity, high turbidity zone and net input from the sediment in the middle estuary. These processes are not reflected in the metal contents of suspended particulate material and superficial sediment, although the dissolved metal variations are a product of particle-water exchanges. This apparent anomaly is attributed to the magnitude of internal resuspendable particle fluxes within the system. Consequently, temporal and spatial variabilities in the composition of suspended particulate material and superficial sediment are determined by physical rather than chemical processes.

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8

Peck, Gillian A., and J. David Smith. "Distribution of dissolved and particulate 226Ra, 210Pb and 210Po in the Bismarck Sea and western equatorial Pacific Ocean." Marine and Freshwater Research 51, no. 7 (2000): 647. http://dx.doi.org/10.1071/mf99170.

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The distribution of the radionuclides 226Ra, 210Pb and 210Po in the dissolved (<0.45 µm) and 210Pb and 210Po in the particulate (>0.45 µm) phases was measured in the upper 300 m of the Bismarck Sea off the Sepik River and along the equator from 143˚E to 152˚E in the western equatorial Pacific Ocean. 210Pb and 210Po occurred principally in the dissolved phase with a 210Po/210Pb ratio <1. Particulate matter had 210Po/210Pb ratios greater than 1.0. Box model calculations yielded an average atmospheric flux of 210Pb of 4.5 mBq cm-2 year-1 to the ocean surface. The average residence times for dissolved 210Po and dissolved 210Pb were 0.27 years and 8.0 years respectively (in the mixed layer) and 1.45 years and 170 years (in the deeper layer). With an average residence time of 0.08 0.03 years, particulate 210Po varied little between the layers. The difference in 210Po and 210Pb residence times reflects the greater particle reactivity of 210Po. The flux of particulate organic carbon was calculated to be 104 21 mg m-2 day-1 from the upper 100 m and 180 22 mg m-2 day-1 from 100–300 m.

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9

Ellwood, Michael J., David A. Hutchins, Maeve C. Lohan, Angela Milne, Philipp Nasemann, Scott D. Nodder, Sylvia G. Sander, Robert Strzepek, Steven W. Wilhelm, and Philip W. Boyd. "Iron stable isotopes track pelagic iron cycling during a subtropical phytoplankton bloom." Proceedings of the National Academy of Sciences 112, no. 1 (December 22, 2014): E15—E20. http://dx.doi.org/10.1073/pnas.1421576112.

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The supply and bioavailability of dissolved iron sets the magnitude of surface productivity for ∼40% of the global ocean. The redox state, organic complexation, and phase (dissolved versus particulate) of iron are key determinants of iron bioavailability in the marine realm, although the mechanisms facilitating exchange between iron species (inorganic and organic) and phases are poorly constrained. Here we use the isotope fingerprint of dissolved and particulate iron to reveal distinct isotopic signatures for biological uptake of iron during a GEOTRACES process study focused on a temperate spring phytoplankton bloom in subtropical waters. At the onset of the bloom, dissolved iron within the mixed layer was isotopically light relative to particulate iron. The isotopically light dissolved iron pool likely results from the reduction of particulate iron via photochemical and (to a lesser extent) biologically mediated reduction processes. As the bloom develops, dissolved iron within the surface mixed layer becomes isotopically heavy, reflecting the dominance of biological processing of iron as it is removed from solution, while scavenging appears to play a minor role. As stable isotopes have shown for major elements like nitrogen, iron isotopes offer a new window into our understanding of the biogeochemical cycling of iron, thereby allowing us to disentangle a suite of concurrent biotic and abiotic transformations of this key biolimiting element.

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10

Karlsson, O. Magnus. "Forms and Variability of Phosphorus in the Baltic Sea–-A Challenge to Ecosystem Modeling." Air, Soil and Water Research 3 (January 2010): ASWR.S6123. http://dx.doi.org/10.4137/aswr.s6123.

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Knowledge of the partitioning between the dissolved and particulate phases of nutrient elements is a key factor in aquatic ecosystem modeling since partitioning regulates the availability to demand ratio of the nutrient in question. This is seldom taken into account in environmental monitoring programs. In this paper, the occurrence and variability of particulate and dissolved phosphorus were studied in the coastal zone of the Baltic Sea. The particulate fraction (PF) of total phosphorus (TP) concentration in coastal waters from some forty stations along the east coast of Sweden was, on average, 0.33. Dissolved inorganic phosphorus (DIP) was a poor predictor of total dissolved phosphorus (DP) representing only 20%-30% of this fraction. Sensitivity analyses showed that the value of PF had a significant impact on modeled predictions of TP concentration in the water on a Baltic sub-basin scale, whereas an applied coastal model was insensitive to variations in PF. Hence, this study encourages further sampling efforts on the partitioning of phosphorus in the open waters of the Baltic Sea.

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11

Lau, Maximilian P., Michael Sander, Jörg Gelbrecht, and Michael Hupfer. "Spatiotemporal redox dynamics in a freshwater lake sediment under alternating oxygen availabilities: combined analyses of dissolved and particulate electron acceptors." Environmental Chemistry 13, no. 5 (2016): 826. http://dx.doi.org/10.1071/en15217.

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Environmental contextAt sediment surfaces, the availability of oxygen is controlled by its downward transport from the water surface and its consumption in microbial metabolism. Microorganisms can also consume substances other than oxygen to dispose of the surplus charge that is generated during microbial metabolism. We investigate the complex dynamics of these other substances when the oxygen availability fluctuates, and thereby contribute to the mechanistic understanding of oxygen-consuming processes in aquatic environments. AbstractBenthic mineralisation in lakes largely controls the availability of oxygen in the water column above the sediment. In stratified lakes with anoxic hypolimnetic waters, mineralisation proceeds by anaerobic respiration using terminal electron acceptors (TEAs) other than O2. In past work, hypolimnetic oxygen consumption has been estimated from vertical concentration profiles of redox-active dissolved species in the water column and the underlying sediment. Electron transfer to and from particulate mineral and organic phases in the sediments was, however, not accounted for, mainly because of methodological constraints. In this work we use an electrochemical approach, mediated electrochemical analysis, to directly quantify changes in the redox states of particulate geochemical phases in a lake sediment. In mesocosm incubations, sediments were subjected to shifting oxygen availability similar to conditions during and after lake overturn events. The temporal redox dynamics of both dissolved and particulate phases in sediments were monitored at a high spatial resolution. We used a combination of experimental and modelling approaches to couple the observed changes in the redox state of dissolved and particulate species in the sediment to the oxygen turnover in the overlying water column. For the studied freshwater sediment, the amount of O2 consumed during the re-oxidation of these phases in the top 21mm of the sediment after switching from hypoxic to oxic conditions corresponded to ~50% of the total sediment oxygen consumption that was estimated from in-lake measurements after the onset of summer stratification. We found that solid phases in the sediments play a more profound role in electron accepting processes than previously considered. Based on these results, we propose that the herein presented analytical method offers the possibility to constrain parameters in theoretical models that simulate benthic redox dynamics including the electron transfer to and from geochemical phases in the sediments.

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12

Valenta, P., R. Breder, L. Mart, H. Rützel, and A. G. A. Merks. "Distribution of Cd and Pb between dissolved and particulate phases in estuaries." Toxicological & Environmental Chemistry 14, no. 1-2 (February 1987): 129–41. http://dx.doi.org/10.1080/02772248709357198.

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13

Ip, Ching-man Carman, Wing-yee Chloe Tang, and Xiang-dong Li. "Trace metals in particulate and dissolved phases in Victoria Harbour, Hong Kong." Chinese Journal of Geochemistry 25, S1 (March 2006): 159. http://dx.doi.org/10.1007/bf02840048.

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14

Ellwood, Michael J., Peter Wilson, Kay Vopel, and Malcolm Green. "Trace metal cycling in the Whau Estuary, Auckland, New Zealand." Environmental Chemistry 5, no. 4 (2008): 289. http://dx.doi.org/10.1071/en07077.

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Environmental context. The accumulation of trace metals from urban runoff is a serious environmental concern. In the present paper we show that, in the case of the Whau Estuary, Auckland, New Zealand, there is a significant particulate Zn input, of which a significant amount of Zn is lost from the particulate phase into the dissolved phase within the water column, and via molecular diffusion across the water–sediment interface. The present study shows that changes in the chemical speciation of Zn, associated with changes in salinity, play a major role in regulating the recycling of this metal between the particulate and dissolved phases. Abstract. Dissolved Zn, Cd, Cu, Fe, and Pb concentrations were measured along a salinity gradient in the Whau Estuary, Auckland, New Zealand. We found a mid-salinity maximum in dissolved Zn and Cd concentrations, consistent with significant loss of these metals from the particulate phase into the dissolved phase. Changes in the chemical speciation of these two metals were coupled to changes in salinity and this was the major driver for Zn and Cd loss from particulate material. Contrastingly, Cu concentrations were conservative with salinity, whereas there was significant scavenging of Fe and Pb from the dissolved phase into the particulate phase. Analysis of sediment pore-water metal concentrations indicated a peak in Zn concentration within the suboxic layer. The peak occurred at a shallower depth than those for Mn and Fe. The concentration gradient across the sediment–water interface suggests that diffusional loss of Zn from the sediment pore water into the overlying water column was occurring. Conversely, the diffusion of Cu from the water column into the sediment pore water was likely to occur because pore-water Cu concentrations were lower than the overlying water column concentrations. The results from the present study show the importance of chemical speciation and the lability of metals attached to particulate material as potentially being a critical determinant on sediment metal concentrations.

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15

Guesmia, M., J. L. Reyss, and C. Cheviet. "Modelling of60Co concentrations in the dissolved and particulate phases in the Loire estuary." Radioprotection 37, no. C1 (February 2002): C1–781—C1–787. http://dx.doi.org/10.1051/radiopro/2002203.

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16

Vistnes, Hanne, Nadine A. Sossalla, Anna Røsvik, Susana V. Gonzalez, Junjie Zhang, Thomas Meyn, and Alexandros G. Asimakopoulos. "The Determination of Polycyclic Aromatic Hydrocarbons (PAHs) with HPLC-DAD-FLD and GC-MS Techniques in the Dissolved and Particulate Phase of Road-Tunnel Wash Water: A Case Study for Cross-Array Comparisons and Applications." Toxics 10, no. 7 (July 19, 2022): 399. http://dx.doi.org/10.3390/toxics10070399.

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Accelerated solvent extraction (ASE) and solid phase extraction (SPE) protocols tailored to either gas chromatography mass spectrometry (GC-MS) or high-performance liquid chromatography coupled to diode-array and fluorescence detection (HPLC-DAD-FLD) were developed for the determination of EPA 16 polycyclic aromatic hydrocarbons (PAHs) in the particulate and dissolved phase of road-tunnel wash water. An analytical approach was developed, assessed, and applied on environmental samples collected from five road tunnels in Norway. The absolute recoveries ranged from 57 to 104% for the particulates, and from 42 to 79% for the dissolved water phase. The target PAH compounds were separated in 34.75 min using the GC method and in 22.50 min by HPLC. In the particulate phases, higher molecular weight PAHs were detected in the range of 0.043 to 0.93 µg/g, and lower molecular weight PAHs were detected in the range of 0.020 to 1.0 µg/g, while the intermediate ones were present in the range of 0.075 to 2.0 µg/g. In contrast to the particulates, the dissolved phase mainly contained lower molecular weight PAHs in the range of 0.0098 to 0.50 µg/L. GC-MS demonstrated lower detection limits (LODs) than HPLC-DAD-FLD for 13 out of the 16 PAHs. A cross-array comparison of the two analytical techniques indicated that some target PAHs were detected solely or in higher concentrations with HPLC-DAD-FLD, indicating the occurrence of false positive peaks or/and co-eluting components. The resulting concentrations in the road tunnel wash water samples were used to calculate specific PAH forensic ratios to pinpoint the potential sources of PAH pollution. These ratios revealed that there are several potential sources for the origin of PAHs in tunnel wash water.

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17

Simpson, Stuart L., Simon C. Apte, and Cheryl M. Davies. "Bacterially Assisted Oxidation of Copper Sulfide Minerals in Tropical River Waters." Environmental Chemistry 2, no. 1 (2005): 49. http://dx.doi.org/10.1071/en04064.

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Environmental Context. It is well known that bacteria can significantly accelerate oxidation rates of copper sulfide minerals under acidic conditions. However, this process is not thought to be important at higher pH. This study reports the bacterially assisted oxidation of copper sulfide minerals in slightly alkaline (pH 8.0–8.3) tropical river waters downstream of a large copper mine. This process leads to significant solubilization of copper from particulate phases. Abstract. Field and laboratory experiments are reported which demonstrate the bacterially facilitated oxidation of copper sulfide minerals in the water column of tropical rivers. When river water samples, collected downstream of a large copper mine, were incubated under controlled laboratory conditions (pH 8.0–8.3) significant dissolved copper release was observed. This was accompanied by an increase in cold acid soluble particulate copper, indicating oxidation of copper sulfides. Dissolved copper release and copper sulfide oxidation were markedly lower in sterile control samples demonstrating biological mediation. In samples collected close to the mine discharge, dissolved copper release ceased after the first 150 h of incubation, presumably following the consumption of easily oxidizable solid copper sulfide phases or armouring of particles with insoluble oxidation products. Attempts to isolate the bacteria responsible were unsuccessful. However, oxidation rates could be enhanced by culturing aliquots of unfiltered river water samples in simple mineral media (pH 7.0) amended only with sulfide. This provided strong evidence that the copper sulfide oxidizing bacteria were chemolithotrophs. Our results suggest that such bacteria are naturally present in mineralized areas and are actively involved in the cycling of particulate copper between sulfide and hydroxy-carbonate forms, thus influencing the solubility and bioavailability of copper.

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18

Hwang, Byung-Gi, Kwan-Soo Jun, Young-Dae Lee, and Wu-Seng Lung. "Importance of DOC in sediments for contaminant transport modelling." Water Science and Technology 38, no. 11 (December 1, 1998): 193–99. http://dx.doi.org/10.2166/wst.1998.0467.

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Contaminants in the interstitial waters are not only dissolved but also associated with a filterable colloidal phase such as DOC. The DOC plays an important role regulating the distribution of chemicals between particulate and dissolved phases since it binds chemicals and makes them unavailable for vertical diffusive exchange. A three-phase partitioning model that consists of free-dissolved, DOC-bound, particulate-bound components of the chemicals involved is used for the contaminant transport model in order to include the effect of DOC on the partition coefficient. The contaminant model is linked to WASP modeling framework to predict remobilization of PCBs in sediments and the fate and transport of the contaminant in overlying waters of the New Bedford Harbor where the harbor has been contaminated with PCBs and heavy metals released from electronic capacitor manufacturers. Simulation of remedial controls indicates that if no action is taken, PCB concentrations will continue to be at elevated levels. Several scenarios for the removal of contaminated sediments have been performed to reduce the elevated PCB concentrations to background levels.

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19

King, Amanda J., James W. Readman, and John L. Zhou. "Behaviour of polycyclic aromatic hydrocarbons in dissolved, colloidal, and particulate phases in sedimentary cores." International Journal of Environmental Analytical Chemistry 87, no. 3 (March 15, 2007): 211–25. http://dx.doi.org/10.1080/03067310601025189.

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Grotti, M., F. Soggia, F. Ardini, and E. Magi. "Major and trace element partitioning between dissolved and particulate phases in Antarctic surface snow." Journal of Environmental Monitoring 13, no. 9 (2011): 2511. http://dx.doi.org/10.1039/c1em10215j.

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Keskitalo, Kirsi H., Lisa Bröder, Dirk Jong, Nikita Zimov, Anna Davydova, Sergei Davydov, Tommaso Tesi, et al. "Seasonal variability in particulate organic carbon degradation in the Kolyma River, Siberia." Environmental Research Letters 17, no. 3 (February 21, 2022): 034007. http://dx.doi.org/10.1088/1748-9326/ac4f8d.

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Abstract Major Arctic rivers are undergoing changes due to climate warming with higher discharge and increased amounts of solutes and organic carbon (OC) draining into rivers and coastal seas. Permafrost thaw mobilizes previously frozen OC to the fluvial network where it can be degraded into greenhouse gases and emitted to the atmosphere. Degradation of OC during downstream transport, especially of the particulate OC (POC), is however poorly characterized. Here, we quantified POC degradation in the Kolyma River, the largest river system underlain with continuous permafrost, during 9–15 d whole-water incubations (containing POC and dissolved OC—DOC) during two seasons: spring freshet (early June) and late summer (end of July). Furthermore, we examined interactions between dissolved and particulate phases using parallel incubations of filtered water (only DOC). We measured OC concentrations and carbon isotopes (δ13C, Δ14C) to define carbon losses and to characterize OC composition, respectively. We found that both POC composition and biodegradability differs greatly between seasons. During summer, POC was predominantly autochthonous (47%–95%) and degraded rapidly (∼33% loss) whereas freshet POC was largely of allochthonous origin (77%–96%) and less degradable. Gains in POC concentrations (up to 31%) were observed in freshet waters that could be attributed to flocculation and adsorption of DOC to particles. The demonstrated DOC flocculation and adsorption to POC indicates that the fate and dynamics of the substantially-sized DOC pool may shift from degradation to settling, depending on season and POC concentrations—the latter potentially acting to attenuate greenhouse gas emissions from fluvial systems. We finally note that DOC incubations without POC present may yield degradation estimates that do not reflect degradation in the in situ river conditions, and that interaction between dissolved and particulate phases may be important to consider when determining fluvial carbon dynamics and feedbacks under a changing climate.

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Hamad, Samera Hussein, James Jay Schauer, Martin Merrill Shafer, Esam Abed Al-Raheem, and Hyder Satar. "The Distribution between the Dissolved and the Particulate Forms of 49 Metals across the Tigris River, Baghdad, Iraq." Scientific World Journal 2012 (2012): 1–13. http://dx.doi.org/10.1100/2012/246059.

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The distribution of dissolved and particulate forms of 49 elements was investigated along transect of the Tigris River (one of the major rivers of the world) within Baghdad city and in its major tributary (Diyala River) from 11 to 28 July 2011. SF-ICP-MS was used to measure total and filterable elements at 17 locations along the Tigris River transect, two samples from the Diyala River, and in one sample from the confluence of the two rivers. The calculated particulate forms were used to determine the particle-partition coefficients of the metals. No major changes in the elements concentrations down the river transect. Dissolved phases dominated the physical speciation of many metals (e.g., As, Mo, and Pt) in the Tigris River, while Al, Fe, Pb, Th, and Ti were exhibiting high particulate fractions, with a trend of particle partition coefficients of [Ti(40) > Th(35) > Fe(15) > Al(13) > Pb(4.5)] * 106 L/kg. Particulate forms of all metals exhibited high concentrations in the Diyala River, though the partition coefficients were low due to high TSS (~270 mg/L). A comparison of Tigris with the major rivers of the world showed that Tigris quality in Baghdad is comparable to Seine River quality in Paris.

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HATZIANESTIS, I., and E. SKLIVAGOU. "Dissolved and Suspended Polycyclic Aromatic Hydrocarbons (PAH) in the North Aegean Sea." Mediterranean Marine Science 3, no. 1 (June 1, 2002): 89. http://dx.doi.org/10.12681/mms.261.

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The distribution and sources of polycyclic aromatic hydrocarbons (PAH) were investigated in the seawater of the North Aegean Sea. The measured PAH concentrations in SPM are generally considered as elevated for open sea waters and were evenly distributed in the area. Their levels in the dissolved phase (1.6-33.0 ng/l) were much higher than those encountered in the corresponding particulate phases (0.04-10.2 ng/l). The PAH patterns in both phases were dominated by the three ring aromatics and their alkylated derivatives, reflecting a predominant contribution of fossil hydrocarbons probably related to ship traffic, whereas no significant inputs from the rivers outfalling in the area were detected. In bottom waters PAH values were generally lower, whereas a higher depletion of the petroleum PAH in comparison with the pyrolytic ones according to depth was observed.

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24

Mundo, Rodrigo, Tetsuya Matsunaka, Hisanori Iwai, Shouzo Ogiso, Nobuo Suzuki, Ning Tang, Kazuichi Hayakawa, and Seiya Nagao. "Interannual Survey on Polycyclic Aromatic Hydrocarbons (PAHs) in Seawater of North Nanao Bay, Ishikawa, Japan, from 2015 to 2018: Sources, Pathways and Ecological Risk Assessment." International Journal of Environmental Research and Public Health 17, no. 3 (February 1, 2020): 904. http://dx.doi.org/10.3390/ijerph17030904.

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To improve the understanding of the emission sources and pathways of polycyclic aromatic hydrocarbons (PAHs) in the coastal environments of remote areas, their particulate and dissolved concentrations were analyzed on a monthly basis from 2015 to 2018 in surface waters of Nanao Bay, Japan. The concentration of the targeted 13 species of PAHs on the United States Environmental Protection Agency (USEPA) priority pollutant list in dissolved and particle phases were separately analyzed by high-performance liquid chromatography (HPLC) coupled to a fluorescence detector. Particulate and dissolved PAHs had average concentrations of 0.72 ng∙L−1 and 0.95 ng∙L−1, respectively. While most of the samples were lower than 1 ng∙L−1, abnormally high levels up to 10 ng∙L−1 were observed in the winter of 2017–2018 for particulate PAHs. Based on the isomer ratios of Flu to Flu plus Pyr, it was possible to determine that the pyrogenic loads were greater than the petrogenic loads in all but four out of 86 samples. The predominant environmental pathway for PAHs in winter was determined to be long-range atmospheric transportation fed by the East Asian winter monsoon, while for the summer, local sources were more relevant. By the risk quotients method, it was determined that PAHs in surface seawater presented a very low risk to marine life during the interannual survey.

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25

Xiao, Min, Fengchang Wu, Yuanbi Yi, Zenglei Han, and Zhongliang Wang. "Optical Properties of Dissolved Organic Matter and Controlling Factors in Dianchi Lake Waters." Water 11, no. 10 (September 21, 2019): 1967. http://dx.doi.org/10.3390/w11101967.

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Characterization of dissolved organic matter (DOM) is useful in understanding environment quality and carbon cycling in the lake system. In this study, the fluorescence of DOM, major ions, and nutrients in water were investigated to understand the sources and the transformation of DOM in Dianchi Lake, the sixth largest freshwater lake in China. The dissolved organic carbon content in water above the deposition layer was higher than 5 mg C∙L−1 but lower than that in pore water. Two primary components of humic (C1) and protein-like components (C2) were identified using parallel factor (PARAFAC) modeling on sample fluorescence spectra. Organic components were related to mineral structures, and encapsulation of bacterial or algal cells into particulates could be disintegrated to release DOM. The aromaticity and the hydrophobicity of optical properties were regulated by percentages of chromophores (CDOM) of DOM in surface water, whereas by percentages of fluorophores (FDOM) in DOM in pore water, the underlying water layer was defined as a belt of transition. The molecular weight enhanced with percentages of C1 in CDOM increased in water above the sediment layer and the pore water at the northern lake site, but molecular weight attenuated with percentages decreased in pore water at the southern lake site. DOM not only originated from particulate decomposition but also derived from internal transformation among different, dissolved organic molecules. Small molecules were aggregated into larger ones, and, conversely, large molecules decomposed into small sizes. Another speculation is that dissolved molecules adsorbed or were encapsulated into particulates or were degraded and released into dissolved phases. The precise factors regulated composition, structure, and spectral properties of dissolved organic matter in the Dianchi Lake. This study highlights that sources of DOM and transformation mechanisms in the lake water could be correlated with nutrients and primary geochemical factors for mobility and distribution in different water compartments.

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26

Pavoni, Elena, Efren García-Ordiales, Stefano Covelli, Pablo Cienfuegos, and Nieves Roqueñí. "Legacy of Past Mining Activity Affecting the Present Distribution of Dissolved and Particulate Mercury and Methylmercury in an Estuarine Environment (Nalón River, Northern Spain)." Applied Sciences 11, no. 10 (May 12, 2021): 4396. http://dx.doi.org/10.3390/app11104396.

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At the Nalón River estuary (Asturias, Northern Spain), the occurrence of Hg is due to historical mining activity which has resulted in environmental issues of great concern. Although several studies have investigated the sediment compartment regarding Hg contamination, no information is currently available on the fate of Hg and MeHg in the water column. Considering different hydrodynamic/seasonal conditions, water samples were collected along the estuary to evaluate Hg and MeHg distribution and partitioning behaviour between solid and aqueous phases. The complementary effect of the river discharge and tidal currents contributed to the prevalence of the dissolved (4.02 ± 1.33 ng L−1) or particulate (8.37 ± 4.20 ng L−1) Hg under different conditions of discharge in summer and autumn, respectively. Conversely, particulate MeHg prevailed when the river flow was low, especially at the estuary mouth (25.8 ± 19.1 pg L−1) and most likely due to the resuspension of fine particles promoted by a stronger tidal current. In comparison with the total Hg concentration, extremely low amounts of dissolved and particulate MeHg were observed, and strong interactions between MeHg and organic carbon highlighted a negligible risk of increased mobility and potential bioaccumulation of MeHg.

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27

Aldridge, J. N. "CSERAM: A Model for Prediction of Marine Radionclide Transport in both Particulate and Dissolved Phases." Radiation Protection Dosimetry 75, no. 1 (January 1, 1998): 99–103. http://dx.doi.org/10.1093/oxfordjournals.rpd.a032255.

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28

Murdock, R. N., M. S. Johnson, J. D. Hemingway, and S. R. Jones. "The Distribution of Radionuclides between the Dissolved and Particulate Phases of a Comtaminated Freshwater Stream." Environmental Technology 16, no. 1 (January 1995): 1–12. http://dx.doi.org/10.1080/09593331608616240.

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29

Chung, Y. "210Pb in the western Indian Ocean: distribution, disequilibrium, and partitioning between dissolved and particulate phases." Earth and Planetary Science Letters 85, no. 1-3 (September 1987): 28–40. http://dx.doi.org/10.1016/0012-821x(87)90018-5.

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30

Milne, Angela, Christian Schlosser, Bronwyn D. Wake, Eric P. Achterberg, Rosie Chance, Alex R. Baker, Alex Forryan, and Maeve C. Lohan. "Particulate phases are key in controlling dissolved iron concentrations in the (sub)tropical North Atlantic." Geophysical Research Letters 44, no. 5 (March 4, 2017): 2377–87. http://dx.doi.org/10.1002/2016gl072314.

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31

Rochelle-Newall, E. J., V. T. Chu, O. Pringault, D. Amouroux, R. Arfi, Y. Bettarel, T. Bouvier, et al. "Phytoplankton diversity and productivity in a highly turbid, tropical coastal system (Bach Dang Estuary, Vietnam)." Biogeosciences Discussions 8, no. 1 (January 18, 2011): 487–525. http://dx.doi.org/10.5194/bgd-8-487-2011.

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Abstract. The factors controlling estuarine phytoplankton diversity and production are relatively well known in temperate systems. Less however is known about the factors affecting phytoplankton community distribution in tropical estuaries. This is surprising given the economic and ecological importance of these large, deltaic ecosystems, such as are found in South East Asia. Here we present the results from an investigation into the factors controlling phytoplankton distribution and phytoplankton-bacterial coupling in the Bach Dang Estuary, a sub-estuary of the Red River system, in Northern Vietnam. Phytoplankton diversity and primary and bacterial production, nutrients and metallic contaminants (mercury and organotin) were measured during two seasons: wet (July 2008) and dry (March 2009). Phytoplankton community composition differed between the two seasons with only a 2% similarity between July and March. The large spatial extent and complexity of defining the freshwater sources meant that simple mixing diagrams could not be used in this system. We therefore employed multivariate analyses to determine the factors influencing phytoplankton community structure. Salinity and suspended particulate matter were important factors in determining phytoplankton distribution, particularly during the wet season. We also show that phytoplankton community structure is probably influenced by the concentrations of mercury species (inorganic mercury and methyl mercury in both the particulate and dissolved phases) and of tri-, di, and mono-butyl tin species found in this system. Freshwater phytoplankton community composition was associated with dissolved methyl mercury and particulate inorganic mercury concentrations during the wet season, whereas, during the dry season, dissolved methyl mercury and particulate butyl tin species were important factors for the discrimination of the phytoplankton community structure. Phytoplankton-bacterioplankton coupling was also investigated during both seasons. In the inshore, riverine stations the ratio between bacterial production and dissolved primary production was high supporting the hypothesis that bacterial carbon demand is supported by allochthonous riverine carbon sources. The inverse was true in the offshore stations, where BP:DPP values were less than 1, potentially reflecting differences in primary production due to shifting phytoplankton community diversity.

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32

Zgheib, Sally, Régis Moilleron, Mohamed Saad, and Ghassan Chebbo. "Partition of pollution between dissolved and particulate phases: What about emerging substances in urban stormwater catchments?" Water Research 45, no. 2 (January 2011): 913–25. http://dx.doi.org/10.1016/j.watres.2010.09.032.

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33

Chung, Y., and R. Finkel. "210Po in the western Indian Ocean: distributions, disequilibria and partitioning between the dissolved and particulate phases." Earth and Planetary Science Letters 88, no. 3-4 (May 1988): 232–40. http://dx.doi.org/10.1016/0012-821x(88)90080-5.

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34

Thanh-Nho, Nguyen, Emilie Strady, Tran–Thi Nhu-Trang, Frank David, and Cyril Marchand. "Trace metals partitioning between particulate and dissolved phases along a tropical mangrove estuary (Can Gio, Vietnam)." Chemosphere 196 (April 2018): 311–22. http://dx.doi.org/10.1016/j.chemosphere.2017.12.189.

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35

Hà, Dang Thi. "ASSESSMENT OF ARSENIC CONTAMINATION IN THE RED RIVER: HIGH RESOLUTION MONITORING COUPLED WITH SPATIAL ANALYSIS BY GIS." Vietnam Journal of Science and Technology 51, no. 6 (March 6, 2018): 779. http://dx.doi.org/10.15625/2525-2518/51/6/11644.

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The Red River (China/Vietnam, A = 155 000 km2) is a typical humid tropics river originating from the mountainous area of Yunan Province in China. Based on two sampling campaigns covering the whole Vietnamese watershed in 40 sites at low and high water levels during 2009, the seasonal and spatial variations of As concentrations in dissolved and particulate phases were determined. The dissolved As concentrations in rainy season were relatively lower than in dry season, suggesting the dilution effect of less arsenic-contaminated water. In contract, the particulate As concentrations during low water level were clearly lower than that during high water level, demonstrating a change phenomenon in As source(s) with hydrology. In addition, in order to assess spatial distribution of the As contamination in the Red River watershed and localize geochemical anomalies, multidimensional statistical analyses combined with As maps generated by GIS tool were used. The results showed that the highest As concentrations are originated from the upstream catchment and strongly decrease from upstream to downstream. Finally, the comparison between dissolved As concentrations from the Red River watershed and the national technical regulation on surface water (QCVN 08:2008/BTNMT) indicated that the quality of water in the Vietnamese Red River watershed can be classified as poor quality in the upstream part and as mediocre quality in the downstream part.

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36

Chen, Tzong-Yueh, and Annelie Skoog. "Effects of Salinity on Abiotic Aggregation of Organic Matter and Subsequent Microbial Responses." Gels 8, no. 12 (December 18, 2022): 836. http://dx.doi.org/10.3390/gels8120836.

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Studies of marine aggregation have focused on determining formation rates of larger particles from small particles. However, it has been shown that particles can form from the dissolved phase, which includes colloidal material. The purpose of this study was to investigate the effect of aggregation on the chemical composition of both the dissolved and particulate phases in two salinity regimes: (1) the coast of Avery Point, Connecticut, USA (AP; salinity of 30.1 psu); (2) the estuary of Thames River, Connecticut, USA (TR; salinity of 5.0 psu). The samples were incubated on a roller table for two days in the dark at a speed of 8 rpm. The mixed collision mechanism of shear and differential sedimentation provided by the roller table enhanced the gross aggregation of particulate organic carbon (POC; 0.75 µM d−1 and 1.04 µM d−1 in AP and TR, respectively). Subsequent microbial degradation led to a negative net aggregation of POC (−5.20 µM d−1 and −1.19 µM d−1 in AP and TR, respectively). Although bacterial abundance remained in a narrow range in this study, the aggregation of organic matter (OM) enhanced planktonic community respiration (CR; CR increased 5.1 mg-C m−3 d−1 and 205.4 mg-C m−3 d−1 in AP and TR, respectively). The collision also led to a gross aggregation of uncharacterized particulate organic matter (POM) transferred from uncharacterized dissolved organic matter (DOM; 0.62 µM-C d−1 and 0.56 µM-C d−1 in AP and TR, respectively). The aggregated, uncharacterized POM could be biologically refractory. The C- and N-yields and enrichment factor (EF) analysis indicated that the organic substrate dynamics in this study were complicated.

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37

Senila, Marin, Erika Andrea Levei, Lacrimioara Ramona Senila, and Marius Roman. "Preliminary Investigation concerning Metals Bioavailability in Waters of Aries River Catchment by Using the Diffusive Gradients in Thin Films Technique." Journal of Chemistry 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/762121.

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The paper presents the metals content and bioavailability in waters of Aries River catchment, Romania. Concentration of labile dissolved metal species measured by diffusive gradients in thin films technique (DGT), metals in colloidal and in particulate phases, and also general physical-chemical indicators of water were determined. Very high total metal concentrations were found in the tributaries that drain the mining areas. However, the influence of the polluted tributaries on the Aries River water quality was moderate, as a consequence of the tributaries low flow rate compared with that of the Aries River. Using the DGT technique the bioavailable metals fractions expressed as % of total dissolved metals concentrations were found to be 28–88% for Cu, 43–72% for Zn, 73–85% for Fe, and 33–70% for Mn. Depending on the used method for dissolved metals determination the classification of waters according to quality classes may differ. Excluding the colloidal metal fractions, DGT measures only truly dissolved metal concentrations. In cases with very high metal contamination the differences between total dissolved and DGT-labile concentrations are unimportant for waters classification. However, where the metals concentration is near the thresholds values the determination method is very important.

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38

Grard, Aline, and Jean-François Deliège. "Characterizing Trace Metal Contamination and Partitioning in the Rivers and Sediments of Western Europe Watersheds." Hydrology 10, no. 2 (February 16, 2023): 51. http://dx.doi.org/10.3390/hydrology10020051.

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Adsorption and desorption processes occurring on suspended and bed sediments were studied in two datasets from western Europe watersheds (Meuse and Mosel). Copper and zinc dissolved and total concentrations, total suspended sediment concentrations, mass concentrations, and grain sizes were analyzed. Four classes of mineral particle size were determined. Grain size distribution had to be considered in order to assess the trace metal particulate phase in the water column. The partitioning coefficients of trace metals between the dissolved and particulate phases were calculated. The objective of this study was to improve the description of the processes involved in the transportation and fate of trace metals in river aquatic ecosystems. Useful data for future modelling, management and contamination assessment of river sediments were provided. As it is confirmed by a literature review, the copper and zinc partitioning coefficients calculated in this study are reliable. The knowledge related to copper and zinc (e.g., partitioning coefficients) will allow us to begin investigations into environmental modelling. This modelling will allow us to consider new sorption processes and better describe trace metal and sediment fates as well as pressure–impact relationships.

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39

Kojima, Keisuke, Shinji Kobayashi, Tomonori Kindaichi, and Noriatsu Ozaki. "Modelling of wet deposition of atmospheric polycyclic aromatic hydrocarbons by the consecutive measurements in an urban area, Japan." Water Science and Technology 62, no. 8 (August 1, 2010): 1922–30. http://dx.doi.org/10.2166/wst.2010.484.

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The wet deposition for particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) was modelled from the consecutive measurements of atmospheric concentration and wet deposition for particulate matter and PAHs in Higashi-Hiroshima city, Japan. In order to estimate the model in detail, the wet deposition was classified with that from gaseous and PM phase. The gaseous PAHs assumed to be dissolved into raindrops according to Henry's constant, and the PAHs attached on atmospheric PM were assumed to be trapped with PM. The PM was classified with coarse (>7 μm) and fine (0.6–7 μm) PM for the calculation of trap. PM and PAHs depositions estimated with the wet deposition model were compared with measured data. The ratios of the measured to the estimated values of PM and PAHs gave close agreement with measurements (0.41–4.29 (1.35: average) for PM and (0.32–3.83 (1.42)) for PAHs) regardless of precipitation. The depositions of PAHs of liquid and particulate phase were on the other hand significantly different from those from gaseous and PM phases respectively. From those differences, the transfer from particulate to liquid phase was suggested to occur during the precipitation.

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40

Martin, J. M., J. M. Mouchel, and P. Nirel. "Some Recent Developments in the Characterization of Estuarine Particulates." Water Science and Technology 18, no. 4-5 (April 1, 1986): 83–92. http://dx.doi.org/10.2166/wst.1986.0183.

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Estuaries and coastal zones are characterised by very varied chemical and physical environments. As a result, heterogenous reactions predominate between dissolved and mineral phases, and with the biota. These reactions primarily affect elements and compounds located at the particulate surface. Thus the determination of surface properties of particles is an important key to understanding interactions of trace elements and organic compounds between particulate and dissolved phases in estuarine and coastal systems. Specific surface area (SSA), cationic exchange capacity (CEC) and heat of immersion (∆H) have been measured on native untreated suspended sediment and after oxidation with 15% H2O2. SSA and ∆H have also been measured on samples Leached with NaOH and Na-dithionite in order to remove amorphous aluminosilicates. Results indicated that SSA is controlled by amorphous oxides and is related to the Al content of samples and their granulometry, suggesting an almost uniform coating of the detrital core by amorphous oxides. On the other hand, CEC and ∆H, which appear to be highly correlated, are controlled by both organic matter and amorphous oxides. Studies on electrophoretic mobility have provided additional data on the excess of charge at the interface between suspended matter and electrolytic medium. Particles in suspension in fresh, sea, and estuarine waters appear ubiquitously to exhibit a small range of negative surface charge. This uniformity is attributed to the presence of organic surface coatings on the particles (Loder and Liss, 1985). Finally, the significance of organic and oxide coatings as carriers of trace metal pollutants is discussed. It is shown that their importance in terms of flux is usually Low despite their major role in controlling solid-liquid interactions.

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41

UNNIKRISHNAN, P., and S. M. NAIR. "Partitioning of trace metals between dissolved and particulate phases in a typical backwater system of Kerala, India." International Journal of Environmental Studies 61, no. 6 (December 2004): 659–76. http://dx.doi.org/10.1080/00207230290011508.

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42

Donner, Mark W., Muhammad Babar Javed, William Shotyk, Kevin A. Francesconi, and Tariq Siddique. "Arsenic speciation in the lower Athabasca River watershed: A geochemical investigation of the dissolved and particulate phases." Environmental Pollution 224 (May 2017): 265–74. http://dx.doi.org/10.1016/j.envpol.2017.02.004.

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43

Bounouira, H., A. Choukri, R. Cherkaoui El Moursli, S. Chakiri, F. Said, M. Bounakhla, and K. Embarch. "Geochemical behaviour of major and trace elements in dissolved and particulate phases of the Bouregreg river (Morocco)." Journal of Radioanalytical and Nuclear Chemistry 295, no. 2 (September 18, 2012): 1067–83. http://dx.doi.org/10.1007/s10967-012-2208-x.

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44

Rose, Clémence, Nadine Chaumerliac, Laurent Deguillaume, Hélène Perroux, Camille Mouchel-Vallon, Maud Leriche, Luc Patryl, and Patrick Armand. "Modeling the partitioning of organic chemical species in cloud phases with CLEPS (1.1)." Atmospheric Chemistry and Physics 18, no. 3 (February 15, 2018): 2225–42. http://dx.doi.org/10.5194/acp-18-2225-2018.

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Abstract. The new detailed aqueous-phase mechanism Cloud Explicit Physico-chemical Scheme (CLEPS 1.0), which describes the oxidation of isoprene-derived water-soluble organic compounds, is coupled with a warm microphysical module simulating the activation of aerosol particles into cloud droplets. CLEPS 1.0 was then extended to CLEPS 1.1 to include the chemistry of the newly added dicarboxylic acids dissolved from the particulate phase. The resulting coupled model allows the prediction of the aqueous-phase concentrations of chemical compounds originating from particle scavenging, mass transfer from the gas-phase and in-cloud aqueous chemical reactivity. The aim of the present study was more particularly to investigate the effect of particle scavenging on cloud chemistry. Several simulations were performed to assess the influence of various parameters on model predictions and to interpret long-term measurements conducted at the top of Puy de Dôme (PUY, France) in marine air masses. Specific attention was paid to carboxylic acids, whose predicted concentrations are on average in the lower range of the observations, with the exception of formic acid, which is rather overestimated in the model. The different sensitivity runs highlight the fact that formic and acetic acids mainly originate from the gas phase and have highly variable aqueous-phase reactivity depending on the cloud acidity, whereas C3–C4 carboxylic acids mainly originate from the particulate phase and are supersaturated in the cloud.

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45

Yao, Min, Zhongjian Li, Xingwang Zhang, and Lecheng Lei. "Polychlorinated Biphenyls in the Centralized Wastewater Treatment Plant in a Chemical Industry Zone: Source, Distribution, and Removal." Journal of Chemistry 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/352675.

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Polychlorinated biphenyls (PCBs) could be dissolved in wastewater or adsorbed on particulate. The fate of PCBs in wastewater is essential to evaluate the feasibility of wastewater treatment processes and the environmental risk. Here dissolved and adsorbed concentrations of twenty concerned PCB congeners and total PCBs have been measured in the centralized wastewater treatment plant of a chemical industry zone in Zhejiang, China. It was found that the dyeing chemical processes were the main source of PCBs, which contributed more than 13.6%. The most abundant PCB was PCB-11 in the liquid and solid phase of each treatment stage, accounting for more than 60% of the total 209 PCBs. Partitioning behavior of PCBs between the dissolved and adsorbed phases suggested that Di-CBs were the dominant isomers (>70%) and more than 89.8% of them was adsorbed on the particles and sludge. The total removal efficiency of∑209 PCBs was only 23.2% throughout the whole treatment process. A weak correlation was obtained between the individual PCB concentration and their log Kowin primary sedimentation, anaerobic hydrolysis, aerobic bioprocess stage, and the whole treatment process.

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46

Saito, Mak A., Abigail E. Noble, Nicholas Hawco, Benjamin S. Twining, Daniel C. Ohnemus, Seth G. John, Phoebe Lam, et al. "The acceleration of dissolved cobalt's ecological stoichiometry due to biological uptake, remineralization, and scavenging in the Atlantic Ocean." Biogeosciences 14, no. 20 (October 20, 2017): 4637–62. http://dx.doi.org/10.5194/bg-14-4637-2017.

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Abstract. The stoichiometry of biological components and their influence on dissolved distributions have long been of interest in the study of the oceans. Cobalt has the smallest oceanic inventory of inorganic micronutrients and hence is particularly vulnerable to influence by internal oceanic processes including euphotic zone uptake, remineralization, and scavenging. Here we observe not only large variations in dCo : P stoichiometry but also the acceleration of those dCo : P ratios in the upper water column in response to several environmental processes. The ecological stoichiometry of total dissolved cobalt (dCo) was examined using data from a US North Atlantic GEOTRACES transect and from a zonal South Atlantic GEOTRACES-compliant transect (GA03/3_e and GAc01) by Redfieldian analysis of its statistical relationships with the macronutrient phosphate. Trends in the dissolved cobalt to phosphate (dCo : P) stoichiometric relationships were evident in the basin-scale vertical structure of cobalt, with positive dCo : P slopes in the euphotic zone and negative slopes found in the ocean interior and in coastal environments. The euphotic positive slopes were often found to accelerate towards the surface and this was interpreted as being due to the combined influence of depleted phosphate, phosphorus-sparing (conserving) mechanisms, increased alkaline phosphatase metalloenzyme production (a zinc or perhaps cobalt enzyme), and biochemical substitution of Co for depleted Zn. Consistent with this, dissolved Zn (dZn) was found to be drawn down to only 2-fold more than dCo, despite being more than 18-fold more abundant in the ocean interior. Particulate cobalt concentrations increased in abundance from the base of the euphotic zone to become ∼ 10 % of the overall cobalt inventory in the upper euphotic zone with high stoichiometric values of ∼ 400 µmol Co mol−1 P. Metaproteomic results from the Bermuda Atlantic Time-series Study (BATS) station found cyanobacterial isoforms of the alkaline phosphatase enzyme to be prevalent in the upper water column, as well as a sulfolipid biosynthesis protein indicative of P sparing. The negative dCo : P relationships in the ocean interior became increasingly vertical with depth, and were consistent with the sum of scavenging and remineralization processes (as shown by their dCo : P vector sums). Attenuation of the remineralization with depth resulted in the increasingly vertical dCo : P relationships. Analysis of particulate Co with particulate Mn and particulate phosphate also showed positive linear relationships below the euphotic zone, consistent with the presence and increased relative influence of Mn oxide particles involved in scavenging. Visualization of dCo : P slopes across an ocean section revealed hotspots of scavenging and remineralization, such as at the hydrothermal vents and below the oxygen minimum zone (OMZ) region, respectively, while that of an estimate of Co* illustrated stoichiometrically depleted values in the mesopelagic and deep ocean due to scavenging. This study provides insights into the coupling between the dissolved and particulate phase that ultimately creates Redfield stoichiometric ratios, demonstrating that the coupling is not an instantaneous process and is influenced by the element inventory and rate of exchange between phases. Cobalt's small water column inventory and the influence of external factors on its biotic stoichiometry can erode its limited inertia and result in an acceleration of the dissolved stoichiometry towards that of the particulate phase in the upper euphotic zone. As human use of cobalt grows exponentially with widespread adoption of lithium ion batteries, there is a potential to affect the limited biogeochemical inertia of cobalt and its resultant ecology in the oceanic euphotic zone.

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47

Qiu, Y. J., та A. Saliot. "Non-aromatic hydrocarbons in ‘dissolved’ phase (< 0·7 μm) and their fractionation between ‘dissolved’ and particulate phases in the changjiang (Yangtse River) Estuary". Marine Environmental Research 31, № 4 (січень 1991): 287–308. http://dx.doi.org/10.1016/0141-1136(91)90018-4.

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Kasimov, Nikolay, Galina Shinkareva, Mikhail Lychagin, Sergey Chalov, Margarita Pashkina, Josefin Thorslund, and Jerker Jarsjö. "River Water Quality of the Selenga-Baikal Basin: Part II—Metal Partitioning under Different Hydroclimatic Conditions." Water 12, no. 9 (August 26, 2020): 2392. http://dx.doi.org/10.3390/w12092392.

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The partitioning of metals and metalloids between their dissolved and suspended forms in river systems largely governs their mobility and bioavailability. However, most of the existing knowledge about catchment-scale metal partitioning in river systems is based on a limited number of observation points, which is not sufficient to characterize the complexity of large river systems. Here we present an extensive field-based dataset, composed of multi-year data from over 100 monitoring locations distributed over the large, transboundary Selenga River basin (of Russia and Mongolia), sampled during different hydrological seasons. The aim is to investigate on the basin scale, the influence of different hydroclimatic conditions on metal partitioning and transport. Our results showed that the investigated metals exhibited a wide range of different behaviors. Some metals were mostly found in the dissolved form (84–96% of Mo, U, B, and Sb on an average), whereas many others predominantly existed in suspension (66–87% of Al, Fe, Mn, Pb, Co, and Bi). Nevertheless, our results also showed a consistently increasing share of metals in dissolved form as the metals were transported to the downstream parts of the basin, closer to the Lake Baikal. Under high discharge conditions (including floods), metal transport by suspended particulate matter was significantly greater (about 2–6 times). However, since high and low water conditions could prevail simultaneously at a given point of time within the large river basin, e.g., as a result of on-going flood propagation, snap-shot observations of metal partitioning demonstrated contrasting patterns with domination of both particulate and dissolved phases in different parts of the basin. Such heterogeneity of metal partitioning is likely to be found in many large river systems. These results point out the importance of looking into different hydroclimatic conditions across space and time, both for management purposes and contaminant modeling efforts at the basin scale.

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Garnier, J. M., J. M. Martin, J. M. Mouchel, and K. Sioud. "Partitioning of trace metals between the dissolved and particulate phases and particulate surface reactivity in the Lena River estuary and the Laptev Sea (Russia)." Marine Chemistry 53, no. 3-4 (August 1996): 269–83. http://dx.doi.org/10.1016/0304-4203(95)00094-1.

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50

He, J., and R. Balasubramanian. "The exchange of SVOCs across the air-sea interface in Singapore's coastal environment." Atmospheric Chemistry and Physics Discussions 9, no. 3 (June 16, 2009): 13235–69. http://dx.doi.org/10.5194/acpd-9-13235-2009.

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Abstract. Coastal areas are vulnerable to the accumulation of semi-volatile organic compounds such as PAHs, OCPs and PCBs from atmospheric inputs. Dry particulate and wet depositions, and air-water diffusive exchange in the Singapore's south coastal area, where most of chemical and oil refinery industries are situated in, were estimated. Based on a yearly dataset, the mean annual dry particulate deposition fluxes of ∑16PAHs, ∑7OCPs and ∑21PCBs were 1328.8±961.1 μg m−2 y−1, 5421.4±3426.7 ng m−2 y−1 and 811.8±578.3 ng m−2 y−1, and the wet deposition of ∑16PAHs and ∑7OCPs were 6667.1±1745.2 and 115.4±98.3 μg m−2 y−1, respectively. Seasonal variation of atmospheric depositions was influenced by meteorological conditions. Air-water gas exchange fluxes had negative values for PAHs, HCHs and DDXs, indicating Singapore's south coast as a sink for the above-mentioned SVOCs. The relative contribution of each depositional process to the total atmospheric input was assessed by annual fluxes. The profile of dry particulate deposition, wet deposition and gas exchange fluxes seemed to be correlated with individual pollutant's properties such as molecular weight and Henry's law constant, etc. For the water column partitioning, the organic carbon-normalized partition coefficients between particulate and dissolved phases (KOC) for both PAHs and OCPs were obtained. The relationships between KOC of PAHs and OCPs and their respective octanol-water partition coefficient (KOW) were examined. In addition, both adsorption onto combustion-derived soot carbon and absorption into natural organic matter for PAHs in marine water column were investigated. Enrichment factors in the sea-surface microlayer (SML) of the particulate phase were 1.2~7.1 and 3.0~4.9 for PAHs and OCPs, and those of dissolved phase were 1.1~4.9 and 1.6~4.2 for PAHs and OCPs, respectively. These enrichment factors are relatively higher than those reported for nearby coastal areas, which are most likely due to more organic surfactants floating in the south coastal surface of Singapore.

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