Статті в журналах: "Zn solid phase speciation"

1

Barrett, J. E. S., K. G. Taylor, K. A. Hudson-Edwards, and J. M. Charnock. "Solid-phase speciation of Zn in road dust sediment." Mineralogical Magazine 75, no. 5 (October 2011): 2611–29. http://dx.doi.org/10.1180/minmag.2011.075.5.2611.

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AbstractX-ray absorption spectroscopy, scanning electron microscopy (SEM) and X-ray diffractometry (XRD) have been used to study the solid-phase speciation of Zn in urban road dust sediments (RDS) in Manchester, UK. X-ray absorption near-edge structure (XANES) analysis using linear combination modelling suggest that the soluble species Zn(NO3)2·6H2O and ZnCl2 represent 70—83%, and Zn-sorbed goethite 17—30%, of the Zn species present. The presence of goethite is not corroborated by extended X-ray absorption fine structure (EXAFS) modelled first shell scattering Zn—O distances of 2.01—2.03 Å, but this may be due to distortion of the Zn octahedra on the goethite surface, or the existence of Zn-sorbed species with other metal hydrous oxides, as inferred by the EXAFS-modelled second shell Fe and Al scatterers. Analysis by EXAFS also suggests that metallic Zn-Cu-Sn-Pb and Zn-silicate phases are present in the RDS, and this is corroborated by SEM and XRD. Other phases suggested by EXAFS include ZnO, franklinite, Zn-sorbed birnessite and zinc formate. Differences between the XANES and other results suggest that model compounds such as Zn-bearing phyllosilicates and metallic Zn phases may have been missing from the XANES fitting. Long-term low-level exposure to the RDS Zn phases identified may lead to an increased risk of cardiovascular or pulmonary diseases.

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Lipatnikova, O. A., T. N. Lubkova, and N. A. Korobova. "Trace element speciation in water and bottom sediments of the Pirogov water reservoir." Moscow University Bulletin. Series 4. Geology, no. 6 (December 28, 2020): 59–68. http://dx.doi.org/10.33623/0579-9406-2020-6-59-68.

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The composition and speciation of trace elements (Cu, Pb, Zn, Cd, Ni, Co, Mn, Fe, Ba, and Sr) in surface water and bottom sediments of the Pirogov water reservoir have been studied. It was found that the metal content in surface water does not exceed the maximum permissible concentration (MPC) for fishery water reservoir excluded Zn (2–9 MPC) and Cu (up to 2 MPC). According to results of thermodynamic calculations, the predominant metal speciation in water is the free ion (Sr, Ba, Zn, Ni, Co, Cd), fulvate (Cu) and carbonate (Pb) complex. The interstitial water is characterized by an increase in the content of sulfate complex of trace elements in loams, the solid phase of which is also characterized by slightly anomalous contents of Zn, Cd, Co, and Ni. According to data of sequential selective procedure, metals are predominantly immobilized in solid phase of bottom sediments in the crystal structure of silicates or bounded to iron and manganese oxides. Only for Cd and Mn exchangeable and bound to carbonates fractions are characterized by considerable relative contents.

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Morrison, G. M. P., D. M. Revitt, and J. B. Ellis. "Metal Speciation in Separate Stormwater Systems." Water Science and Technology 22, no. 10-11 (October 1, 1990): 53–60. http://dx.doi.org/10.2166/wst.1990.0288.

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Biogeochemical processes, affecting metal speciation in a gullypot system and at stormwater outfalls, are investigated. Ionic Pb and Cu species released from road sediments by add rain are scavenged by dissolved organic material and suspended solids as a result of a rise in pH through the road/gullypot system. Cadmium and Zn tend to remain in the dissolved phase. Bacterial activity and add dissolution produce increases in dissolved metal in the gullypot liquor and it is these metals which contribute to the early storm profile. Metals in basal gullypot sediments are readily mobilised during high volume/intensity storms. The resulting stormwater contains dissolved ionic forms of Cd and Zn, while Pb is mostly adsorbed to suspended solid surfaces. Copper also binds to solids, although approximately 50% is transported by dissolved organic material (molecular weight ≈ 1000-5000). For the separation of directly toxic metal species, anodic stripping voltammetry at polymer coated electrodes is preferred. Lead and Cu are present as iron/humic colloids and organic complexes respectively, which are not directly toxic to algae. Cadmium is predominantly ionic and inorganically complexed and therefore directly toxic. It is recommended that the highly toxic lipid soluble metal species should be analysed in stormwater.

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Ray, Prasenjit, and Siba Prasad Datta. "Solid phase speciation of Zn and Cd in zinc smelter effluent-irrigated soils." Chemical Speciation & Bioavailability 29, no. 1 (November 4, 2016): 6–14. http://dx.doi.org/10.1080/09542299.2016.1247656.

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Degtiareva, Antonina, and Maria Elektorowicz. "A Computer Simulation of Water Quality Change Due to Dredging of Heavy Metals Contaminated Sediments in the Old Harbour of Montreal." Water Quality Research Journal 36, no. 1 (February 1, 2001): 1–19. http://dx.doi.org/10.2166/wqrj.2001.001.

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Abstract Aquatic sediments accumulate heavy metals that are discharged into the environment. This study investigates possible water quality changes due to release of heavy metals such as Cd, Ni, Zn and Pb into the water column during dredging of anoxic sediments in the Old Harbour of Montreal. An environmental impact assessment of the sediment removal requires estimating the speciation of heavy metals in the water column with and without the solid phase. Chemical equilibria in the St. Lawrence River water are calculated using the program EQUILIB from the software FACT. Results show that the water is oversaturated with respect to CaMg(CO3)2 and Fe(OH)3. It is speculated that (ZnO)(Fe2O3) and (NiO)(Fe2O3) control the solubility of Zn and Ni in the water. The speciation of heavy metals in pore water of anoxic sediments is calculated, taking into account that the corresponding sulfides are solid phases and control their solubility. The impact of various scenarios on the area of concern is reviewed from an ecotoxicological perspective. Dredging might change the redox and acid-base conditions in the water column. Dredging can lead to an increase in the concentration of heavy metals in the water column and a change of metal speciation, but its impact will be less visible if the sediments contain high levels of calcium acting as a buffer.

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Jeyakumar, Paramsothy, Paripurnanda Loganathan, Sivalingam Sivakumaran, Christopher W. N. Anderson, and Ronald G. McLaren. "Copper and zinc spiking of biosolids: effect of incubation period on metal fractionation and speciation and microbial activity." Environmental Chemistry 5, no. 5 (2008): 347. http://dx.doi.org/10.1071/en08031.

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Environmental context. Global sewage sludge (biosolids) production is increasing as a result of rapidly growing human population and ensuing industrial activities. Disposal of this waste is becoming a serious environmental issue because the high levels of heavy metals in biosolids can upset soil microbial activity and nutrient balance when the waste is added to forest or agricultural lands. In the present study, a biosolid matrix was spiked with copper and zinc as a model for an environmental scenario. The findings of the present study are applicable to environmental regulations that seek to protect agriculture land, human and animal health, and soil and drinking water quality, in scenarios where biosolids are applied to soil. Abstract. Biosolids were amended separately with three levels of copper and zinc sulfate, and anaerobically incubated for 117 days. Copper in the unamended-biosolids solid phase was mainly found in the organic and residual fractions (85–95%). Copper addition decreased the percentage of Cu in these fractions and increased the percentage of Cu in the oxide and specifically adsorbed fractions. Zinc in the solid phase was mainly associated with the oxide (35–65%), specifically adsorbed (25–30%), and the exchangeable fractions (10–40%). Relatively, all Cu in the solution phase was complexed with organic matter; Zn was present mainly as Zn2+ and as an electrically neutral ion pair, ZnSO40. Metals were almost completely incorporated into the biosolids matrix by Day 55. Dehydrogenase activity was reduced by 50% (EC50, effective concentration for 50% activity reduction) at the total solution-phase Cu and Zn concentrations of 0.1 and 20 mg L–1, respectively, and solid-phase exchangeable Cu and Zn concentrations of 410 and 670 mg kg–1, respectively.

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Hernandez-Soriano, M. C., and J. C. Jimenez-Lopez. "Linking dissolved organic matter composition to metal bioavailability in agricultural soils: effect of anionic surfactants." Biogeosciences Discussions 12, no. 7 (April 14, 2015): 5697–723. http://dx.doi.org/10.5194/bgd-12-5697-2015.

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Abstract. The bioavailability of metals in soil is only partially explained by their partition among the solid and aqueous phase and is more related to the characterization of their speciation in the soil solution. The organic ligands in solution that largely determine metal speciation involve complex mixtures and the characterization of fluorescence components of dissolved organic matter (DOM) can identify pools of molecules that participate in metal speciation, this being essential for risk assessment. The bioavailability of Cd, Cu, Pb and Zn in three agricultural soils was examined in the laboratory to recreate irrigation with greywater enriched in anionic surfactants (Aerosol 22 and Biopower). Field capacity and saturation regimes were considered for this study. Irrigation with aqueous solutions of the anionic surfactants increased total DOM concentrations and metals in the soil solution (Pb > Cu > Zn > Cd). Significant correlation (p < 0.05) between the readily available pool of metals with the concentration of DOM was determined for Cu (r = 0.67), Pb (r = 0.82) and Zn (r = 0.68). However, speciation analysis performed with the software WHAM indicated that mobilisation of DOM and metals into the soluble phase resulted in a low concentration of free ion activities and promoted the formation of metal-organo complexes. The characterization of fluorescence components revealed that DOM in soil solution from soils irrigated with Aerosol 22 was enriched in a reduced quinone-like and a humic-like component. Besides, fluorescence quenching provided further evidence of metal complexation with organic ligands in solution. Hence, metal mobilization in soil irrigated with surfactant enriched greywater occurs with solubilisation of high affinity organic ligands, which substantially decreases the potential risk of metal toxicity.

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8

Degtiareva, A., and M. Elektorowicz. "Change in the water quality of industrial channels due to resuspension of sediments contaminated with heavy metals." Water Supply 1, no. 2 (March 1, 2001): 27–35. http://dx.doi.org/10.2166/ws.2001.0018.

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Industrial channels were used extensively during the two previous centuries and have become heavily contaminated. This study investigates possible water quality changes in the Lachine Canal (Montreal) due to the release of heavy metals (Cd, Ni, Zn and Pb) into the water column during resuspension of anoxic sediments subjected to potential remediation. This release can be initiated by dredging activities for sediment removal. Equilibrium in the water from the Lachine Canal has been calculated using the program EQUILIB from the software FACT. The speciation of heavy metals in the water column was calculated with and without a solid phase before and after possible dredging. Speciation of heavy metals in pore water of anoxic sediments has been calculated, taking into account that corresponding sulfides are the solid phases controlling their solubility. The concentration of heavy metals under anoxic conditions considered could decrease by 8 orders of magnitude. The impact of various scenarios in the area of concern was reviewed from an ecotoxicological perspective. Dredging can possibly change the redox and acid–base conditions in the water column. The impact of dredging will be less if sediments contain calcium. Dredging can lead to an increase in the concentration of heavy metals in the water column and a change of metal speciation.

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9

Goen, Ho, and Qiao Liang. "Chromium speciation in municipal solid waste: effects of clay amendment and composting." Water Science and Technology 38, no. 2 (July 1, 1998): 17–23. http://dx.doi.org/10.2166/wst.1998.0093.

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The addition of clay in the form of bauxite refining residue (red mud) prior to composting has been suggested as a way to control heavy metal mobility in compost. Leachability and plant availability of metals in a mixture of grass clippings and sawdust spiked with metal solution was markedly reduced during the composting process. The fate of metals in municipal solid waste compost applied to land was examined by using a sequential step extraction to investigate metal speciation (into exchangeable and bound to carbonate forms, to Mn & Fe oxides, to organic matter and in residue phase) in red mud amended compost. The effects of red mud and the composting process on metal speciation in the compost for Cd, Cr, Cu, Ni, Pb and Zn were investigated, and a comparison of some effects with biosolids compost was made. Addition of red mud reduced the metal mobility and the potential hazard of releasing metals from compost through promoted precipitation, adsorption and complexation of free metal cations to red mud. Red mud however, was not able to desorb metals bound to organic matter. Since most of the metals in the municipal solid waste were not usually bound to organic matter, the addition of red mud prior to composting fixed the free metal ions before they bound to this fraction. Results for Cr speciation are reported in this paper.

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10

García-Meza, J. V., M. I. Contreras-Aganza, J. Castro-Larragoitia, and R. H. Lara. "Growth of Photosynthetic Biofilms and Fe, Pb, Cu, and Zn Speciation in Unsaturated Columns with Calcareous Mine Tailings from Arid Zones." Applied and Environmental Soil Science 2011 (2011): 1–9. http://dx.doi.org/10.1155/2011/732984.

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Mine tailing remediation aims to reduce the rate of sulfide mineral oxidation. Earlier studies showed that photosynthetic biofilms may act as a physical barrier against oxygen diffusion. Currently, a long-term assay (6 months) is required to evaluate the solid phase redistribution of the Pb, Fe, Cu, and Zn originally present in historic and calcareous mine tailing samples (in our case from a semiarid region in North-Central Mexico). The presence of biofilms may provide chemical gradients and physical conditions that shift the proportion of Fe, Cu, and Zn originally associated with oxides to carbonates and organic matter/sulfide fractions.

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11

Qiao, L., and Goen Ho. "The effect of clay amendment on speciation of heavy metals in sewage sludge." Water Science and Technology 34, no. 7-8 (October 1, 1996): 413–20. http://dx.doi.org/10.2166/wst.1996.0649.

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When sewage sludge is used as a soil conditioner, heavy metal contamination can limit its application rates. The potential hazard of heavy metals is, however, dependent on the physico-chemical forms of the metals in the sludge and soil. Bauxite refining residue (red mud) has been used to reduce the mobility and availability of heavy metals in municipal solid waste compost. In the present research a sequential step extraction was employed to investigate metal speciation (into exchangeable, bound to carbonate, to Mn & Fe oxides, to organic matter and in residue phase) and the effect of red mud on metal speciation in sewage sludge for Cd, Cr, Cu, Ni, Pb and Zn. The effect of red mud addition on metal distribution in sewage sludge compost was significant. Red mud addition can effectively reduce the metal mobility and the potential hazard of releasing metals from sludge due to the further breakdown of organic matter. Drying of sludge makes heavy metals more available. Red mud addition will be desirable in such a case. Plant available metals (determined by DTPA extraction) are, however, not as effectively reduced except for Pb and Zn.

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Hao, Yupei, Xiongyi Miao, Hongwei Liu, and Dan Miao. "The Variation of Heavy Metals Bioavailability in Sediments of Liujiang River Basin, SW China Associated to Their Speciations and Environmental Fluctuations, a Field Study in Typical Karstic River." International Journal of Environmental Research and Public Health 18, no. 8 (April 10, 2021): 3986. http://dx.doi.org/10.3390/ijerph18083986.

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The bioavailability of heavy metals (HMs) in sediments is closely related to the security of the aquatic environment, but their impacts are poorly researched, particularly in karstic rivers. Therefore, Liujiang River Basin was taken as an example in this study. Seven HMs were analyzed to determine the bioavailability and speciations of HMs in sediments. Moreover, the impacts of environmental factors on HMs were identified. The obtained results suggested that HMs in the sediments are all within their permissible exposure limit (PEL), but Cd and Zn are significantly higher than the soil baseline. Most HMs were found to be in a residual fraction, while their exchangeable fraction was found to be in an extremely low ratio. HMs in bioavailable parts are significantly higher than in the exchangeable and carbonate-bound phases but lower than in the non-residual phase, which demonstrated that HM bioavailability is not confined to the exchangeable and carbonate-bound phases. The correlation coefficients commonly decreased with decreasing speciation ratios, which suggested that the overall bioavailability of metals should be determined by speciation ratios instead of speciations themselves. Noteworthily, most HMs in the residual form were found to be significantly correlated with their overall bioavailability, which highlighted the potential bioavailability of residual form. The non-correlations between pH, electrical conductivity (EC), total dissolved solids (TDS), and HM bioavailability suggested that HMs in the carbonate-bound phase are stable and unsusceptible to environmental variations, while the significant correlations between redox potential (Eh), turbidity, organic matter (OM), main grain size (Mz), and HM bioavailability suggested that HMs in the reducible and oxidizable forms are susceptible to environmental fluctuations. Therefore, the variation of HM bioavailability in karstic rivers is largely regulated by their reducible and oxidizable forms instead of their carbonate-bound form.

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Lofts, Stephen. "POSSMs: a parsimonious speciation model for metals in soils." Environmental Chemistry 18, no. 8 (February 22, 2022): 335–51. http://dx.doi.org/10.1071/en21100.

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Environmental context Predicting the chemistry of metals is important for understanding their movement and impacts in the environment. Metal chemistry models are generally complex and difficult to apply, but a simpler model, which does not need large amounts of input data, can also provide good results. A simpler model can be more easily included in large-scale models of metal transport and impacts in the environment. Abstract Mechanistic geochemical models are useful for detailed study of the speciation of metals in well-characterised soils, but can be challenging to apply when driving soil compositional data are sparse, for example, at large scales. Empirical models, using minimal driving data, have been developed either for prediction of solid–solution partitioning or for the computation of the free metal ion from the total or geochemically active metal. This work presents an empirical speciation model, POSSMs (ParsimOniouS Speciation of Metals in soils), which predicts the free, solution-bound and sorbed metal in a soil in a single calculation, using a minimal set of soil parameters. The model has been parameterised for Ni, Cu, Zn, Cd and Pb using datasets of geochemically active soil metal and solution phase composition. The parameterised model can also be used to compute the free metal ion from the solution metal. The model was tested by applying it to literature datasets on the speciation of metals in soil solutions and extracts, and on the metal solid–solution partitioning. The performance of the model was comparable to other empirical models of similar complexity. Some test datasets produced biased predictions, particularly in the underestimation of measured free ion at circumneutral and alkaline pH, where the model predicted low free ion concentrations. The model is not a replacement for mechanistic geochemical models, but is a useful tool for soil metal speciation where comprehensive driving data are not available.

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Deary, Michael E., Patrick M. Amaibi, John R. Dean, and Jane A. Entwistle. "New Insights into Health Risk Assessments for Inhalational Exposure to Metal(loid)s: The Application of Aqueous Chemistry Modelling in Understanding Bioaccessibility from Airborne Particulate Matter." Geosciences 11, no. 2 (January 23, 2021): 47. http://dx.doi.org/10.3390/geosciences11020047.

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Aqueous modelling of chemical speciation in simulated lung fluid (SLF) enables a better understanding of the underlying chemical factors that influence metal(loid) inhalation bioaccessibility from airborne particulate matter. Such an approach can be used to supplement experimental techniques that are integral to the health risk assessment of metal(loid) exposure by inhalational routes. In this paper, we modelled the aqueous chemistry of airborne particulate-bound metal(loid)s (As, Cu, Mn, Pb and Zn) in a SLF based on Gamble’s solution (neutral pH). The modelling was performed using two software packages (Geochemist’s Workbench 14 and OLI Studio 9.5) and a total of five thermochemical databases (GWB Thermo, MINTEQ, PHREEQC, WATEQ4F and the default database for OLI Studio). Modelled results were compared with experimentally determined bioaccessibilities for the NIST 2710a standard reference material (SRM) and with literature-reported bioaccessibilities for NIST 1648a and BCR 038 SRMs. Whilst the models correctly describe the observed increase in bioaccessibility for more dilute solid/liquid extraction ratios, the performance of the models against the fractional bias of the mean (FBmean) and the normalised mean square error (NMSE) statistical metrics was generally outside the acceptance criteria. Findings from an analysis of the main aqueous chemical species predicted to be present in SLF indicate that carbonate and chloride complexes of Cu, Mn, Pb and Zn predominate, whilst free cations (for Cu, Mn and Zn) and hydroxides (for Cu) also play a role in solubilisation. Arsenic is not predicted to form significant complexes with the SLF components and is present in solution mainly as the HAsO42− ion and its conjugate acid, H2AsO4−. For modelled runs where glycine and citrate were present, significant increases in the bioavailability of Cu and Zn were predicted as a result of complexation with these ligands. An additional finding from our experimental bioaccessibility results for NIST 2710a was that the inclusion of the lung fluid surfactant dipalmitoylphosphatidylcholine (DPPC) in the SLF did not significantly affect the bioaccessibility. Our study provides useful insights into the likely aqueous- and solid-phase speciation of metal(loid)s in SLF and highlights that future developments in this area should consider the role of mineralogy and surface interactions.

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Itoh, Akihide, Masato Ono, Kota Suzuki, Takumi Yasuda, Kazuhiko Nakano, Kimika Kaneshima, and Kazuho Inaba. "Simultaneous Determination of Cr, As, Se, and Other Trace Metal Elements in Seawater by ICP-MS with Hybrid Simultaneous Preconcentration Combining Iron Hydroxide Coprecipitation and Solid Phase Extraction Using Chelating Resin." International Journal of Analytical Chemistry 2018 (November 13, 2018): 1–8. http://dx.doi.org/10.1155/2018/9457095.

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In the present study, ICP-MS with a new hybrid simultaneous preconcentration combining solid phase extraction using chelating resin and iron hydroxide coprecipitation in one batch at a single pH adjustment (pH 6.0) were developed for multielement determination of trace metal ions in seawater. In multielement determination, the present method makes it possible to determine Cr(III), As(V), Se (IV), and other 14 trace metal elements (Ti, V, Co, Ni, Cu, Zn, Zr, Ge, Cd, Sb, Sn, W, Pb, and U) in seawater. Moreover, for speciation analyses of Cr, As, and Se, the pH dependence on recovery for the different chemical forms of Cr, As, and Se was investigated. In speciation analyses, Cr, As, and Se were determined as the total of Cr (III) and a part of Cr (VI), total of As (III) and As (V), and Se(IV), respectively. Determination of total of Se and Cr(VI) remains as future task to improve. Nevertheless, the present method would have possibility to develop as the analytical method to determine comprehensively most metal elements in all standard and guideline values in quality standard in environmental water in Japan, that is, most toxic metal elements in environmental water.

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Drapeau, Clémentine, Rabei Argane, Cécile Delolme, Denise Blanc, Mostafa Benzaazoua, Rachid Hakkou, Thomas Baumgartl, Mansour Edraki, and Laurent Lassabatere. "Lead Mobilization and Speciation in Mining Waste: Experiments and Modeling." Minerals 11, no. 6 (June 5, 2021): 606. http://dx.doi.org/10.3390/min11060606.

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Mining produces significant amounts of solid mineral waste. Mine waste storage facilities are often challenging to manage and may cause environmental problems. Mining waste is often linked to contaminated mine drainage, including acidic waters with more or less elevated concentrations of trace metals such as lead. This work presents a study on the mobilization of lead from waste from two typical mining sites: Zeida and Mibladen, two now-closed former Pb–Zn mines in the Moulouya region of Morocco. Our research investigates the mobilization potential of Pb from the waste of these mines. The study involved acid–base neutralization capacity tests (ANC–BNC) combined with geochemical modeling. Experimental data allowed for the quantification of the buffering capacity of the samples and the mobilization rates of lead as a function of pH. The geochemical model was fitted to experimental results with thermodynamic considerations. The geochemical model allowed for the identification of the mineral phases involved in providing the buffering capacity of carbonated mining waste (Mibladen) and the meager buffering capacity of the silicate mining waste (Zeida). These cases are representative of contaminated neutral drainage (CND) and acid mine drainage (AMD), respectively. The results highlight the consistency between the ANC–BNC experimental data and the associated modeling in terms of geochemical behavior, validating the approach and identifying the main mechanisms involved. The modeling approach identifies the dissolution of the main solid phases, which impact the pH and the speciation of lead as a function of the pH. This innovative approach, combining ANC–BNC experiments and geochemical modeling, allowed for the accurate identification of mineral phases and surface complexation phenomena, which control the release of lead and its speciation in drainage solutions, as well as within solid phases, as a function of pH.

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Sydow, Mateusz, Łukasz Chrzanowski, Alexandra Leclerc, Alexis Laurent, and Mikołaj Owsianiak. "Terrestrial Ecotoxic Impacts Stemming from Emissions of Cd, Cu, Ni, Pb and Zn from Manure: A Spatially Differentiated Assessment in Europe." Sustainability 10, no. 11 (November 8, 2018): 4094. http://dx.doi.org/10.3390/su10114094.

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Metallic elements present in livestock manure as co-contaminants have the potential to cause terrestrial ecotoxic impacts when the manure is used as fertilizer on agricultural soils. The magnitude of this impact at country scale in Europe has, to date, not been quantified. Here, we address this knowledge gap by combining recently developed national emission inventories of Cd, Cu, Ni, Pb and Zn releases from manure with metal- and soil-specific comparative toxicity potentials (CTP) calculated for cropland grid cells at 1 × 1 km resolution for 33 European countries. The CTPs account for speciation in environmental fate, exposure and effects, including reduction in the solid-phase reactivity of a metal when it is associated with organic carbon present in the manure. Given the scarcity of inventory data at sub-national level, it was assumed that each unit area of cropland within a given country has the same probability to receive manure. The resulting CTPs span a range of several orders of magnitude reflecting the influence of soil type and properties on the speciation patterns and resulting CTP values. However, when combined with the use of manure in each European country, the resulting national impact scores were mainly explained by the total mass input of metal released to soil rather than by geographic variability in the CTP values. Simple linear regression is then sufficient to predict terrestrial ecotoxic impacts from input mass. Although some changes in ranking of metals and countries were observed, both mass- and impact-based comparisons between metals agreed that Zn and Cu are dominant contributors to total impacts, and that top contributing countries were those emitting the largest amounts of metals. Our findings show that spatially differentiated impact assessment is important for ranking of countries when differences in national emission inventories between countries are smaller than a factor of two (Ni), a factor of three (Cd, Cu, Zn) or a factor of four (Pb). In other cases, ranking of countries can be based on national emission inventories.

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Fonseca, Rita, Carla Patinha, Fernando Barriga, and Manuela Morais. "Role of the sediments of two tropical dam reservoirs in the flux of metallic elements to the water column." Water Science and Technology 66, no. 2 (July 1, 2012): 254–66. http://dx.doi.org/10.2166/wst.2012.169.

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In tropical climates, the high rainfall and temperature, throughout the annual cycle, allow high leaching rates of metallic elements from the basin upstream, which accumulate in the reservoirs. However, the concentration of these elements in natural waters is usually lower than expected, due to the ease of adsorption and co-precipitation in solid phases. We have studied two tropical dam reservoirs in Brazil, Três Marias (Minas Gerais) and Tucuruí (Pará), with the aim of understanding the correlation between physical–chemical parameters of the water column, chemical and mineralogical characteristics of the accumulated material and the solubility, mobilization and precipitation of metals in reservoirs. Metals speciation performed in selected samples determined that metallic micronutrients are preferentially adsorbed or retained through precipitation/co-precipitation onto fine-size charged crystalline/amorphous Fe-oxides. Under the prevailing reducing and low pH conditions of the bottom reservoirs, some adsorbed metals (particularly Fe and Mn) are easily released from their metal bearing-phases and mobilized to the aqueous phase of sediments, which show high levels of soluble forms of these elements. However, the solubilization process and the release to the water column are not very extensive, as abundances of metals such as Fe, Mn, Zn and Cu in water are low, although increasing with depth.

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Abderrazzak, Baba Ahmed, Boudahri Fethi, and Kebir Tahar. "Evaluation of the Speciation of Heavy Metals (Cd, Pb, Zn, Cr and As) in the Different Horizons of an Agricultural Soil." International Journal of Biology and Biomedical Engineering 16 (March 27, 2022): 233–40. http://dx.doi.org/10.46300/91011.2022.16.29.

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This research has enabled the assessment of environmental risk related to potential transfers of metal trace elements such as lead, cadmium, zinc, chromium and arsenic in agricultural soils whose cultivation is nearby barley. From the industrial discharge of the technical discharge center (CET) of the municipality of Oued El Djemaa is located in the Wilaya de Rélizane-Algeria and close to solid domestic waste from industrial discharges. To meet this main objective, several analyzes were carried out, based on the first place on the chemical extraction of heavy metals by treating water. This extraction has highlighted a fairly strong accumulation of cadmium, arsenic and zinc in the soil. If the total levels of heavy metal by lawy water allow for a first state of fixtures, it is more specified according to the method of Tessier which has allowed an estimate of the future of pollutants and a risk approach. The sequential extraction on the ground showed a significant source of pollution by cadmium which is mainly related to the carbonates that makes it mobile and which constitutes a potential threat to the environment. On the other hand, arsenic and zinc are mainly related to the residual phase and the reducible phase respectively so they are little mobile in the soil and do not show threat. This research work has made it possible to access fine knowledge of the fate of metal pollutants (Cd, Pb, Zn, Cr and As) in agricultural soil. He also highlighted shadow points requiring multidisciplinary research.

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20

Mattigod, S. V., P. F. Pratt, and E. B. Schalscha. "Trace Metal Speciation in a Soil Profile Irrigated with Waste Waters." Water Science and Technology 17, no. 9 (September 1, 1985): 133–42. http://dx.doi.org/10.2166/wst.1985.0087.

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A chemical equilibrium computer model: GEOCHEM, was used to predict the trace metal behavior in a soil profile if subjected to a long-term irrigation with waste waters. Various categories of interactions such as acid-base equilibria, soluble complex formation of metals with organic and inorganic ligands, dissolution-precipitation reactions and ion-exchange reactions were included in simulation. The metal-soluble organic interactions were accounted for by a mixture model. The computations included a 10 metal - 15 ligand system with 262 soluble complex species and 21 possible solid phases. The results predicted that a major fraction of alkali elements in solution tend to be in free ionic forms, whereas, major fractions of the alkaline earths were predicted to be present in adsorbed and/or precipitated forms. In marked contrast, significant soluble fractions of transition series metals were predicted to be in adsorbed and/or complexed forms. The degree of attenuation of these transition series elements moving through the soil profile seems to be governed mainly by the degree of adsorption on soil surfaces and the tendency of these elements to form soluble organic complexes. The predicted mobilities of these elements in this soil profile was Cu > Ni > Zn > Cd. Application of this equilibrium model appears to provide a first approximation approach to simulate the trace element behavior in soil profiles.

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21

Altundag, Huseyin, Mustafa Imamoglu, Secil Doganci, Erkan Baysal, Sinem Albayrak, and Mustafa Tuzen. "Determination of Heavy Metals and Their Speciation in Street Dusts by Inductively Coupled Plasma-Optical Emission Spectrometry after a Community Bureau of Reference Sequential Extraction Procedure." Journal of AOAC INTERNATIONAL 96, no. 4 (July 1, 2013): 864–69. http://dx.doi.org/10.5740/jaoacint.11-269.

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Abstract Sequential selective extraction techniques are commonly used to fractionate the solid-phase forms of metals in soils. This procedure provides measurements of extractable metals from media, such as acetic acid (0.11 M), hydroxyl ammonium chloride (0.1 M), hydrogen peroxide (8.8 M) plus ammonium acetate (1 M), and aqua regia stages of the sequential extraction procedure. In this work, the extractable Pb, Cu, Mn, Sr, Ni, V, Fe, Zn, and Cr were evaluated in street dust samples from Sakarya, Turkey, between May and October 2009 using the three-step sequential extraction procedure described by the Community Bureau of Reference (BCR, now the Standards, Measurements, and Testing Programme) of the European Union. The sampling sites were divided into 10 categories; a total of 50 street dusts were analyzed. The determination of multielements in the samples was performed by inductively coupled plasma-optical emission spectrometry. Validation of the proposed method was performed using BCR 701 certified reference material. The results showed good agreement between the obtained and the certified values for the metals analyzed.

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22

Dung, Tran, Elvira Vassilieva, Rudy Swennen, and Valérie Cappuyns. "Release of Trace Elements from Bottom Ash from Hazardous Waste Incinerators." Recycling 3, no. 3 (August 14, 2018): 36. http://dx.doi.org/10.3390/recycling3030036.

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Bottom ash is the major by-product of waste incineration and can contain trace elements (As, Cd, Co, Cu, Cr, Mo, Ni, Pb, and Zn) with concentrations up to thousands of mg·k−1. In this study, a combination of different extractions and leaching tests (i.e., CH3COOH and ammonium-EDTA (Ethylenediaminetetraacetic acid) extractions and pHstat leaching tests) was used to investigate the potential release of trace elements from bottom ash samples derived from hazardous waste incineration plants. Although large variations have been found in the release of trace elements by different extractions, in general, the highest concentrations of most trace elements (except As and Mo) were released with the CH3COOH extraction, whereas the release of As and Mo was highest with the ammonium-EDTA extraction. Kinetics of element release upon acidification based on a pHstat leaching test at pH 4 could be related to the solid-phase speciation of some selected trace elements. The relatively high-potential mobility and elevated total concentrations of some trace elements imply a threat to the environment if these bottom ashes are not treated properly. Results of the present study may be useful to develop potential treatment strategies to remove contaminants and eventually recover metals from bottom ash.

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23

Chica, Paola Posligua, Carlos Banchón Bajaña, and Elvito Villegas. "A Heavy Metal Network: Connecting Remediation Strategies." KnE Engineering 3, no. 1 (February 11, 2018): 88. http://dx.doi.org/10.18502/keg.v3i1.1416.

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Heavy metals in the environment are negatively affecting ecosystems and human life. The anthropogenic source of heavy metals has increased because of sludge from wastewater plants, tanneries, fertilizers, pesticides, and mining industry. As well as environmental conditions change, there is an effect of sedimentation of heavy metals in natural sediments which affect groundwater sources. Thus, the relevance of the present bibliometric work is to address the different interactions between heavy metals and natural sediments. Therefore, this work claims a perspective to predict heavy metal precipitation behaviors in the presence of cations and anions, changes of pH considering its mineral and organic forms, and, solid and liquid phase displacement, migrations towards the contaminated soil and cationic stabilization of heavy metals. In this sense, Cd, As, Mo, Cr, Al, Mn, Al, Cd, Hg, Zn, Pb, Cu, Co, and Ni are mostly correlated with basic pH and Ca/Mg/Fe/Mn minerals. This network has also found that there is a link connection between the contamination source i.e. fertilizers, pesticides and biosolids, and physical-chemical parameters like ionic strength, oxidation-reduction potential, and salinity. Thus, the scope of the present work includes a different perspective in looking remediation strategies by the generation of a connectionist system.Keywords: Speciation, bioaccumulation, adsorption, recalcitrance, network

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24

Mizerna, Kamila. "Determination of forms of heavy metals in bottom ash from households using sequential extraction." E3S Web of Conferences 44 (2018): 00116. http://dx.doi.org/10.1051/e3sconf/20184400116.

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The paper presents the results of heavy metals mobility obtained by sequential extraction method and leaching test. Heavy metals in solid waste material occur in different forms and phases that differ in terms of the toxicity, mobility and bioavailability. The sequential extraction analysis is widely used in order to predict the behaviour of heavy metals in a solid material. The sequential extraction methods involve a gradual separation of metals in various forms by means of specific extractants. The material used in the research applied bottom ash derived from households. The results of heavy metals concentrations (Cd, Pb, Ni, Cr, Cu, Zn) in extractable forms and total content in waste were presented. The five forms of heavy metals were determined. The concentrations of heavy metals were analyzed by FAAS. The lowest concentrations of analyzed heavy metals were determined in the exchangeable form. The author observed that the particular elements occurred mainly in forms: zinc and cadmium associated with carbonates, lead and copper in the organic and residual form, chromium and nickel in the residual form. Heavy metals in the residual fraction do not pose a possible environment hazard. The application of speciation analysis of heavy metals in bottom ash provide the means to assess the content of dissoluble forms of metals in water relative to their total content. This information is useful in assessing the migration capabilities of heavy metal ions from waste to the ground-water environment. The potential for the reuse of bottom ash was also discussed in the paper.

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25

Essington, M. E., and S. V. Mattigod. "Lanthanide Solid Phase Speciation." Soil Science Society of America Journal 49, no. 6 (November 1985): 1387–93. http://dx.doi.org/10.2136/sssaj1985.03615995004900060011x.

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26

Griggs, Christopher, Steven Larson, Goujing Liu, Deborah Felt, W. Andy Martin, Michelle Thompson, and Catherine Nestler. "Solid-Phase Tungsten Speciation by Differential Digestion." Environmental Forensics 11, no. 3 (September 10, 2010): 275–81. http://dx.doi.org/10.1080/15275922.2010.494966.

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27

Mester, Zoltán, and Ralph Sturgeon. "Trace element speciation using solid phase microextraction." Spectrochimica Acta Part B: Atomic Spectroscopy 60, no. 9-10 (October 2005): 1243–69. http://dx.doi.org/10.1016/j.sab.2005.06.013.

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28

Yalçin, Serife, and X. Chris Le. "Speciation of arsenic using solid phase extraction cartridges." Journal of Environmental Monitoring 3, no. 1 (2001): 81–85. http://dx.doi.org/10.1039/b007598l.

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29

Urasa, I. T., S. F. Macha, and W. El-Maaty. "Application of Solid-Phase Extraction in Metal Speciation." Journal of Chromatographic Science 35, no. 11 (November 1, 1997): 519–24. http://dx.doi.org/10.1093/chromsci/35.11.519.

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30

Wauters, J., M. J. Madruga, M. Vidal, and A. Cremers. "Solid phase speciation of radiocaesium in bottom sediments." Science of The Total Environment 187, no. 2 (August 1996): 121–30. http://dx.doi.org/10.1016/0048-9697(96)05133-9.

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31

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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32

Ravishankar, B. R., J. C. Auclair, and R. D. Tyagi. "Partitioning of Heavy Metals in Some Quebec Municipal Sludges." Water Quality Research Journal 29, no. 4 (November 1, 1994): 457–70. http://dx.doi.org/10.2166/wqrj.1994.029.

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Abstract The process efficiency of metal bioleaching from sewage sludges depends upon various physicochemical characteristics of sludges and the forms in which metals are present in these sludge solids. The aim of this research work was to evaluate the metal speciation in some Quebec sludges with the help of a sequential extraction procedure, in order to better predict the bioleaching process. The distribution of Al, Cu, Fe, Mn and Zn in exchangeable, sorbed, organically bound, carbonate, and residual forms were compared among both undigested and digested sludges. Metal redistribution after aerobic sludge stabilization was also studied. Results indicate that the organic and residual fractions were the principal metal binding phases. Copper was present mostly in the residual fraction while the other metals were mostly organically bound. Statistical tests showed that metal speciation varied significantly from one sludge to another. In terms of metal distribution pattern observed, these sludges could not be regrouped according to the sludge type, their total solids concentration or their total metal concentration. However, the variation in metal distribution among Quebec sludges was similar to the variation range found in the U.K. and U.S. sludges. The metals showed a tendency to redistribute and move towards the organic fraction in stabilized sludges. In conclusion, the present study shows that sewage sludges of different origins do not have similar metal distribution and hence, the speciation of metals must be considered for each sludge on an individual basis in order to predict their fate during the bioleaching process.

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33

Hutton, C., D. W. Bryce, W. Russeau, H. J. Glass, L. E. T. Jenkin, W. T. Corns, and P. B. Stockwell. "Aqueous and solid-phase speciation of arsenic in Cornish soils." Mineralogical Magazine 69, no. 5 (October 2005): 577–89. http://dx.doi.org/10.1180/0026461056950272.

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AbstractCornwall (UK) has suffered extensive arsenic contamination due to the historic mining and processing of mineral ores. Standard procedures for contaminated land risk assessment (DEFRA and Environment Agency, 2002a) are probably unworkable in Cornwall, with a very large number of sites classified as contaminated by arsenic. Methods of measuring the speciation and mobility of arsenic are essential for effective and rapid risk assessments of arsenic contamination.Three clusters of lysimeters were installed in three different areas of an arsenic-contaminated Cornish site. A novel phosphoric acid microwave extraction technique was applied to the soils removed from the lysimeter holes; HPLC-HG-AFS analysis showed the majority of solid-phase arsenic to be arsenate (AsV). Pore waters obtained from the lysimeters showed variable, relatively low levels of arsenite (AsIII) and arsenate (AsV) to be present (<1–129 μg l–1). Less toxic arsenate predominated in most pore waters, with the presence of minor amounts of arsenite suggesting heterogeneous redox conditions. Pore-water arsenic concentrations were strongly positively related to solid-phase arsenate concentrations.The use of techniques that assess the speciation of arsenic both in the solid and aqueous phases of a soil provides important information about the mobility of arsenic. The methodology presented in this paper may offer a novel basis for risk assessments of other contaminated sites.

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34

Kostka, Joel E., and George W. Luther. "Partitioning and speciation of solid phase iron in saltmarsh sediments." Geochimica et Cosmochimica Acta 58, no. 7 (April 1994): 1701–10. http://dx.doi.org/10.1016/0016-7037(94)90531-2.

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35

Mester, Zoltan, Ralph Sturgeon, and Janusz Pawliszyn. "Solid phase microextraction as a tool for trace element speciation." Spectrochimica Acta Part B: Atomic Spectroscopy 56, no. 3 (March 2001): 233–60. http://dx.doi.org/10.1016/s0584-8547(00)00304-9.

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36

De Boom, Aurore, Jean-Emmanuel Aubert, and Marc Degrez. "Carbonation of municipal solid waste incineration electrostatic precipitator fly ashes in solution." Waste Management & Research: The Journal for a Sustainable Circular Economy 32, no. 5 (April 9, 2014): 406–13. http://dx.doi.org/10.1177/0734242x14527637.

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Carbonation was applied to a Pb- and Zn-contaminated fraction of municipal solid waste incineration electrofilter fly ashes in order to reduce heavy metal leaching. Carbonation tests were performed in solution, by Na2CO3 addition or CO2 bubbling, and were compared with washing (with water only). The injection of CO2 during the washing did not modify the mineralogy, but the addition of Na2CO3 induced the reaction with anhydrite, forming calcite. Microprobe analyses showed that Pb and Zn contamination was rather diffuse and that the various treatments had no effect on Pb and Zn speciation in the residues. The leaching tests indicated that carbonation using Na2CO3 was successful because it gave a residue that could be considered as non-hazardous material. With CO2 bubbling, Pb and Zn leaching was strongly decreased compared with material washed with water alone, but the amount of chromium extracted became higher than the non-hazardous waste limits for landfilling.

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37

Fotovat, Amir, and Ravendra Naidu. "Ion exchange resin and MINTEQA2 speciation of Zn and Cu in alkaline sodic and acidic soil extracts." Soil Research 35, no. 4 (1997): 711. http://dx.doi.org/10.1071/s96079.

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The bioavailability of trace metals, their accumulation by organisms, and their toxicity to terrestrial and aquatic organisms can be understood better in terms of trace metal species. Although there are numerous chemical techniques used for the determination of ionic species, most are tedious, time-consuming, and not practical for routine analyses. Alternatives to these chemical techniques are computer speciation models that often have an incomplete database on metal–organic chemistry, yet scientists continue to use these techniques for estimation of trace metal activities. In this study we compare the cation exchange resin (Amberlite) and the MINTEQA2 geochemical model for the speciation of zinc (Zn2+) and copper (Cu2+) in the aqueous phase of 11 soils varying widely in chemical composition. The pHw(1:5) of these soils ranged from 5·3 to 9·1, while the total soil aqueous phase concentrations of Zn and Cu were in the ranges 1–71 and 5–74 µg/L, respectively. Preliminary equilibration studies revealed that 24-h contact between resin and sample solution was sucient to exchange all free ions onto the resin bead. By using this equilibration time, the effects of temperature, solution composition, and pH on the resin distribution coeficients (Kd) for Zn and Cu were investigated. These studies revealed that temperature did not significantly influence the Zn and Cu resin distribution coecient. Solution composition such as the presence of Ca, Mg, and Al, however, had a marked effect on the Kd value. Although the Kd value was not sensitive to changes in solution pH (4·5–7·1), it increased at pH >7·1. These results suggest that soil solution composition must be considered during metal ion speciation using the resin beads. Changes in Zn and Cu concentrations, however, did not influence the Kd values of these metals. The cation exchange resin method was modified for speciation of solutions containing very low concentration (<50 µg/L) of Zn. Comparison of the 2 speciation techniques demonstrated excellent agreement for free hydrated Zn2+ and Cu2+ in the soils studied.

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38

Fontàs, Clàudia, Enriqueta Anticó, and Victòria Salvadó. "Design of a Hollow Fiber Supported Liquid Membrane System for Zn Speciation in Natural Waters." Membranes 8, no. 4 (September 27, 2018): 88. http://dx.doi.org/10.3390/membranes8040088.

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A supported liquid membrane-hollow fiber system (HFSLM) has been developed to determine zinc speciation in aquatic environments. The liquid membrane consisted of an organic solution of bis-(2-ethylhexyl)phosphoric acid (D2EHPA) impregnated in the microporous of a polypropylene hollow fiber. The membrane contacted both the donor solution, that contained the metal and the stripping solution, placed in the lumen of the hollow fiber, where the metal was preconcentrated. Different parameters affecting the Zn2+ transport efficiency have been evaluated such as the composition of both the donor and stripping solutions as well as the membrane phase. Extraction and transport efficiencies of free Zn(II) higher than 90% were obtained with a liquid membrane consisting of a 0.1 M D2EHPA solution in dodecane and a 0.1 M HNO3 solution as the stripping phase. The developed HFSLM was used to study the effect of different ligands (EDTA and citric acid) in the donor phase of Zn(II) transport and to investigate the selectivity of the membrane towards Zn when other metals were also present. Finally, the HFSLM system was successfully applied to estimate the free Zn(II) concentrations in three water samples from a mining area. Moreover, the HFSLM system facilitates the analytical determination of trace Zn(II) levels allowing the achievement of enrichment factors of around 700 in the stripping phase.

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39

Li, Yue Han, Ai Rong Zheng, and Zhi Kai Ma. "Speciation of Heavy Metals in the Surface Sediments from Northern Beibu Gulf." Advanced Materials Research 518-523 (May 2012): 1977–81. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.1977.

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The four species of heavy metals (Cu, Zn, Pb, Cr, Cd) were analyzed using BCR (the Bureau Communautaire de Reference) sequential extraction method. Results showed that, about the contents the four species (exchangeable and carbonate state, Fe-Mn oxides state, organic and sulfide state and residual state) in surface sediment, the average contents of Cu were 0.94 μg/g, 2.17 μg/g, 1.18 μg/g and 13.19 μg/g, respectively. the average contents of Pb were1.51 μg/g, 12.90 μg/g, 4.51 μg/g and 16.42 μg/g, respectively; the average contents of Zn were 1.82 μg/g, 13.00 μg/g, 4.20 μg/g and 48.97 μg/g, respectively; the average contents of Cd were 0.010 μg/g, 0.012 μg/g, 0.005 μg/g and 0.063 μg/g, respectively; the average contents of Cr were 0.32 μg/g, 2.98 μg/g, 4.22 μg/g and 13.19 μg/g, respectively. The predominant species of Cu, Zn, Pb, Cr, Cd is residual state. The relative abundance in residual state for these elements followed the order: Cr＞Cu＞Zn＞Cd＞Pb. The pollution degree was assessed with ratio of secondary phase to primary phase. Results showed that the sediments in the northern Beibu Gulf were uncontaminated with Cu, Zn and Cr. 12 % of the sites was slightly polluted with Cd. 47 % of the sites were polluted with Pb.

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40

Zielińska, Katarzyna. "Solid phase microextraction speciation analysis of triclosan in aqueous media containing sorbing nanoparticles." Environmental Chemistry 11, no. 1 (2014): 72. http://dx.doi.org/10.1071/en13167.

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Environmental context Speciation analysis of organic compounds in aquatic media is often performed using solid phase microextraction with the assumption that only the free organic form is accumulated. We show that in the presence of silica nanoparticles, this interpretation is confounded by partitioning of nanoparticulate-bound compounds between water and the solid phase, as well as their aggregation at solid–bulk medium interfaces. Equilibrium measurement of the target analyte is feasible if the solid phase is protected by a suitable membrane. Abstract Solid phase microextraction (SPME) is applied in the speciation analysis of the hydrophobic compound triclosan in an aqueous medium containing sorbing SiO2 nanoparticles (NPs). It is found that these NPs, as well as their complexes with triclosan, partition between the bulk medium and the solid phase poly(dimethylsiloxane) (PDMS). Furthermore, they appear to aggregate at the PDMS–water interface. The total triclosan concentration in the solid phase thus includes both the free and the NP-bound forms. Proper computation of the analyte concentration in the sample medium requires (i) consideration of the speciation of triclosan inside the solid phase and (ii) elimination of the effects of aggregation of NP complexes at the solid phase–bulk medium interface. Possible solutions include application of a protective membrane with pore size smaller than the NP diameter. This allows measurement of the free triclosan concentration, albeit at the cost of longer accumulation times and loss of kinetic information on the triclosan–NP complex.

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41

Nauha, Elisa, Matteo Lusi, and Pance Naumov. "Control of a thermosalient phase transition by solid solutions." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C985. http://dx.doi.org/10.1107/s2053273314090147.

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Thermosalient crystals that exhibit macro-scale motion upon phase transition could be useful as actuators that are capable of converting thermal energy into motion or mechanical work in macroscopic devices.[1] The application capability of these miniature actuators for energy conversion depends on the temperature range and dynamics of transition. While the thermo-mechanical performance cannot be systematically varied with a pure molecular crystal, solid solutions could present a way to intentionally tune both the dynamics and the temperature of the transition in a continuous manner (Figure 1). To verify this hypothesis, Zn(2,2'-bpy)Br2,[2] was selected as a thermosalient material which could form solid solutions (or mixed complexes) with Zn(2,2'-bpy)Cl2. Only one form (isomorphous to one of the two Zn(2,2'-bpy)Br2forms) has been reported for the chloride.[3] The results indicate that indeed, the two complexes form solid solutions in varying ratios. The mixed crystals undergo the same phase transformation as the pure Zn(2,2'-bpy)Br2at a Cl/Br-ratio-dependent temperature. The temperature and dynamics of the thermosalient phenomenon correlates with the Cl/Br-ratio.

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42

Zielińska, Katarzyna, Herman P. van Leeuwen, Sylvain Thibault, and Raewyn M. Town. "Speciation Analysis of Aqueous Nanoparticulate Diclofenac Complexes by Solid-Phase Microextraction." Langmuir 28, no. 41 (October 2012): 14672–80. http://dx.doi.org/10.1021/la303143w.

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43

Türker, Ali Rehber. "Separation, Preconcentration and Speciation of Metal Ions by Solid Phase Extraction." Separation & Purification Reviews 41, no. 3 (July 2012): 169–206. http://dx.doi.org/10.1080/15422119.2011.585682.

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44

Amin, Alaa S., and Mohammed A. Kassem. "Chromium speciation in environmental samples using a solid phase spectrophotometric method." Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 96 (October 2012): 541–47. http://dx.doi.org/10.1016/j.saa.2012.05.020.

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45

Wisawapipat, Worachart, and Ruben Kretzschmar. "Solid Phase Speciation and Solubility of Vanadium in Highly Weathered Soils." Environmental Science & Technology 51, no. 15 (July 11, 2017): 8254–62. http://dx.doi.org/10.1021/acs.est.7b01005.

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46

GASSER, UBALD G., and RANDY A. DAHLGREN. "SOLID-PHASE SPECIATION AND SURFACE ASSOCIATION OF METALS IN SERPENTINITIC SOILS." Soil Science 158, no. 6 (December 1994): 409–20. http://dx.doi.org/10.1097/00010694-199415860-00003.

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47

Breynaert, Eric, Andreas C. Scheinost, Dirk Dom, André Rossberg, Jacqueline Vancluysen, Elena Gobechiya, Christine E. A. Kirschhock, and André Maes. "Reduction of Se(IV) in Boom Clay: XAS Solid Phase Speciation." Environmental Science & Technology 44, no. 17 (September 2010): 6649–55. http://dx.doi.org/10.1021/es100569e.

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48

Valencia, M. "Speciation of selenium (IV) in natural waters by solid phase spectrophotometry." Talanta 49, no. 4 (July 12, 1999): 915–21. http://dx.doi.org/10.1016/s0039-9140(99)00088-0.

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Deng, Dongyan, Shu Zhang, He Chen, Lu Yang, Hui Yin, Xiandeng Hou, and Chengbin Zheng. "Online solid sampling platform using multi-wall carbon nanotube assisted matrix solid phase dispersion for mercury speciation in fish by HPLC-ICP-MS." Journal of Analytical Atomic Spectrometry 30, no. 4 (2015): 882–87. http://dx.doi.org/10.1039/c4ja00436a.

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Tsurusaki, Tatsuya, and Takeshi Ohgai. "Mechanical Properties of Solder-Jointed Copper Rods with Electrodeposited Sn-Zn Alloy Films." Materials 13, no. 6 (March 14, 2020): 1330. http://dx.doi.org/10.3390/ma13061330.

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Анотація:

Enforced solid solution type Sn-Zn alloy films were electrochemically synthesized on Cu substrate from an aqueous solution containing citric acid complexes. The electrodeposition behavior of Sn-Zn alloys was classified to a normal co-deposition type, in which electrochemically nobler Sn deposits preferentially compared to Zn. Electrodeposited Sn-Zn alloy films were composed of a non-equilibrium phase, like an enforced solid solution, which was not observed in an equilibrium phase diagram of an Sn-Zn binary alloy system. By applying a thermal annealing process at 150 °C for 10 minutes, a pure Zn phase was precipitated from an electrodeposited Sn-based solid solution phase with excessively dissolved Zn atoms. During the soldering process, intermetallic phases such as Cu3Sn and Cu5Zn8 were formed at the interface between an Sn-Zn alloy and Cu substrate. Tensile strength and fracture elongation of solder-jointed Cu rods with Sn-8 at.%Zn alloy films reached ca. 40 MPa and 12%, respectively.

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