The investigation of landslides and slope deformation processes may require the integration of a ... more The investigation of landslides and slope deformation processes may require the integration of a wide range of data types, collected using different approaches, such as geomorphological, geotechnical and geophysical surveys. Among this latter category, seismic noise method can be used to detect and better understand the geometry of landslide slip surfaces. Indeed, a slip surface may generate evident contrasts in shear wave velocity due to changes in seismic impedance, generated by the different seismic velocity and density of materials at landslide boundaries. The H/V or Nakamura method allows to have a punctual information about the depth of the main impedance contrasts, thus, by performing a spatial interpolation of an adequate number of punctual depth measures, is possible to reliably estimate the depth and geometry of the slip surfaces with good accuracy. This study is focused on the relation between the number of the employed single-station seismic noise measurements and the goodness of the resulting, inferred, slip surface(s) for landslides. The final aim is to detect, if it exists, a threshold in the number of measurements beyond which the information obtained is redundant, since the variations in terms of morphology observed in the reconstructed impedance contrast surfaces become negligible. The proposed approach was validated at Castagnola Landslide (Liguria, Italy), where direct measures of the subsoil stratigraphy were available, then applied to another case study, i.e., the Roccalbegna Landslide (Tuscany, Italy), where no direct measurements, apart from those of the shallow layer geotechnical properties, were available. The experiments carried out are a proof-of-concept of the opportunities that this approach can offer.
Although terrestrial hydrothermal systems are considered among the most fascinating environments,... more Although terrestrial hydrothermal systems are considered among the most fascinating environments, how their unique and extreme conditions can affect microorganisms selection and the role in biogeochemical cycles has not yet been well elucidated. A combined geochemical and microbiological exploration in waters and sediments from ten sampling points along a sharp temperature gradient (15–90 °C) within an extremely acidic hydrothermal system (Pisciarelli Spring, Campi Flegrei area, southern Italy) displayed how hydrothermal fluids influence the microbial dynamics. This area was characterized by high levels of reduced gaseous species (e.g. H2S, H2, CH4, CO), and very low pH values (<2.3). Thermodynamic calculations revealed a high microbial catabolic potential in oxidation/reduction reactions of N-, S-, and Fe-bearing species. Overall, an increase of the archaeal/bacterial abundance ratio was observed by decreasing temperature and pH values. In particular, Archaea and Bacteria were p...
The terrestrial environment is an important contributor of microplastics (MPs) to the oceans. Urb... more The terrestrial environment is an important contributor of microplastics (MPs) to the oceans. Urban streams, strictly interwoven in the city network and to the MPs’ terrestrial source, have a relevant impact on the MP budget of large rivers and, in turn, marine areas. We investigated the fluxes (items/day) of MPs and natural fibers of Mugnone Creek, a small stream crossing the highly urbanized landscape of Florence (Italy) and ending in the Arno River (and eventually to the Tyrrhenian Sea). Measurements were done in dry and wet seasons for two years (2019–2020); stream sediments were also collected in 2019. The highest loads of anthropogenic particles were observed in the 2019 wet season (109 items/day) at the creek outlet. The number of items in sediments increased from upstream (500 items/kg) to urban sites (1540 items/kg). Fibers were the dominant shape class; they were mostly cellulosic in composition. Among synthetic items, fragments of butadiene-styrene (SBR), indicative of ti...
Carbon capture and storage (CCS) is considered a valid option to reduce the CO2 concentration in ... more Carbon capture and storage (CCS) is considered a valid option to reduce the CO2 concentration in atmosphere. The gas is collected from industrial plants, then injected and stored underground in geological reservoirs. A very wide range of information about chemical-physical characteristics of the sequestration site is therefore needed and, among them, data on porosity microstructure are crucial. Part of the processes which affect micro-porosity and act during and after the rock formation can be reconstructed by studying micro-porosity features. In this work, different experimental approaches have been combined to reconstruct the mineral association, bulk chemistry and microporous structure of rocks from a natural CO2 reservoir (which represents a natural analogue of a CCS site). The fluid reservoir, i.e. Caprese Reservoir, was discovered while drilling PSS1 borehole in San Cassiano Basin (Eastern Tuscany, Central Italy) and consists of sedimentary rocks (Burano Fm.) interbedded with altered volcanic rocks, its depth being about 3,300 m with respect to the land surface. At 3,700 m depth fluid pressure and temperature are 700 bars and 120 \ub0C respectively, with a calculated density for CO2 of 860 Kg\ub7m-3. The study was conducted on the volcanic rocks altered by CO2 from the PSS1 wellbore drill cores and on some volcanic rocks unaffected by the presence of CO2. Lastly, rocks from the Burano Formation, unavailable from PSS1, have been sampled on outcrop. Drill core samples corresponding to the depth 3,864-3,871 m with respect to PSS1 log, have been investigated with SEM-EDS, XRD, EMP, ICP-MS and LOI and for the mineralogical and chemical characterization. The SANS/VSANS experiments at LLB (Saclay, France) served for microporous structure investigation of PSS1 rocks, volcanic rocks from Eastern Alps (IG1) and the Albani Hills (IG2 and IG3) unaffected by CO2 and Burano Formation
&amp;lt;p&amp;gt;Due to their spread, abundance and potential impact on food security and... more &amp;lt;p&amp;gt;Due to their spread, abundance and potential impact on food security and human health, microplastics (MPs) are emerging global pollutants. Metropolitan areas are among the main sources of MPs (1 &amp;amp;#956;m - 5 mm); indeed, about 80% of the MPs found in the oceans come from freshwaters. In particular, impervious surfaces runoff in urban areas results in the transport of large quantities of solid wastes, comprising MPs, to the superficial water bodies. Thus, the ecological state of urban streams represents a reliable indicator to evaluate the environmental impact of a city. In this study, we report data about MPs in stream sediments and waters of a minor urban stream, the Mugnone Creek (MC), which flows across the highly urbanized city of Florence (Italy) and discharges to the Arno River.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Several sites along the 17 km-long MC were chosen, including &amp;amp;#8220;greenfield&amp;amp;#8221; sites upstream of the Florence urban area, urban-impacted sites located along congested roads, and the MC outlet. The stream sediments were collected in June 2019, while stream waters were recovered via glass bottles twice a year (June and December) in 2019 and 2020, to account for seasonal variability. Stream discharge was simultaneously determined during water sampling to allow mass flow calculations of contaminants.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Water samples were filtered onto glass microfiber filters (&amp;amp;#248; 47 mm) and observed by HD digital stereomicroscope; a similar method was followed for sediments after a density separation step (NaCl saturated solution) and H&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; digestion. Fourier Transform Infrared Spectroscopy (FT-IR) was used for identification and characterization of MPs. Microparticles classification was based on polymer type, shape and colour.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;MPs concentration in sediments showed an increasing trend from the pre-urban site to the outlet. A maximum value (1.540 MPs/kg) was reached immediately after the Terzolle Creek confluence, which drains the large University Hospital District of Careggi. Fibers were the dominant shape class of polymers observed and blue/black items stand out among the colour classes. The highest concentrations of MPs in water samples were recorded during winter seasons (up to 16.000 items/m&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;), with a predominance of fibers and blue/black colours. Polymer classification by FTIR indicated the presence of (in order of abundance): PA (polyamide), PET (Polyethylene Terephthalate), SBR (butadiene-styrene rubber), PP (Polypropylene), blend PP+PE (PP+Polyethylene), PTFE (Polytetrafluoroethylene) and PU (Polyurethane). The black-SBR polymers likely related to tyre abrasion occurring during vehicles driving, since they were especially found on a site close to traffic-congested roads. In addition to synthetic particles, high concentrations of natural fibers (mainly cellulose) were found in waters at all sites. Up to 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt; synthetic particles are estimated to be discharged daily by MC to the Arno River during the winter season, a load much higher than creeks with similar urbanization context worldwide. Mass loads of natural fibers were of the same order of magnitude of MPs in every season.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Studies are in progress to elucidate the impact on local biota and to characterize the anthropic pressure on the Arno River, aiming to improve the knowledge about the environmental status of one of the main Italian river basins.&amp;lt;/p&amp;gt;
One of the main constraints in assessing shallow landslide hazards through physically based model... more One of the main constraints in assessing shallow landslide hazards through physically based models is the need to characterize the geotechnical parameters of the involved materials. Indeed, the quantity and quality of input data are closely related to the reliability of the results of every model used, therefore data acquisition is a critical and time-consuming step in every research activity. In this perspective, we reviewed all official certificates of tests performed through 30 years at the Geotechnics Laboratory of the Earth Science Department (University of Firenze, Firenze, Italy), compiling a dataset in which 380 points are accurately geolocated and provide information about one or more geotechnical parameters used in slope stability modeling. All tests performed in the past (in the framework of previous research programs, agreements of cooperation, or to support didactic activities) were gathered, homogenized, digitalized, and geotagged. The dataset is based on both on-site ...
Open image in new window In this work we perform an assessment of the geotechnical and hydrologic... more Open image in new window In this work we perform an assessment of the geotechnical and hydrological parameters affecting the occurrence of landslides. The aim of this study is to improve the reliability of the physically-based model HIRESSS (HIgh REsolution Slope Stability Simulator), for the forecasting of shallow landslides. The model and the soil characterization has been tested in northern Tuscany, in Italy, along the Apennine chain, an area that is historically affected by shallow landslides. In the area selected, the main geotechnical and hydrological parameters controlling the shear strength and permeability of soils have been determined by in situ measurements integrated by laboratory analyses. Around 60 survey points have been analyzed. The data obtained have been studied in order to assess the relationships existing among the different parameters and the bedrock lithology. Soil properties have been then statistically characterized and used to define the input parameters in...
&lt;p&gt;Urbanization is a striking phenomenon, responsible for the development of cities... more &lt;p&gt;Urbanization is a striking phenomenon, responsible for the development of cities as complex and highly dynamic systems. One of the most pressing issues in urban areas is water cycle management, which directly influences the availability and the quality of this resource. Urban streams are highly vulnerable to the impacts resulting from the increasing urbanization and they have often lost most of their pristine, natural character.&lt;/p&gt;&lt;p&gt;We hereby present the preliminary results of the multidisciplinary StrEams urbaN Ecological City plAnning (SENECA) project, which is not only but mainly devoted to characterizing the chemical features of stream waters and sediments of the Mugnone Creek (MC). MC is a typical example of an urban stream, crossing the city of Florence (Italy) and eventually discharging to the Arno River, that has suffered an intense denaturation due to the urban sprawl, such as several diversions, canalizations and rectifications, alterations of the stream bed and riparian habitat, widespread concrete revetment of the banks and burial of short stream tracts.&lt;/p&gt;&lt;p&gt;Different sites along the 17-km long MC were investigated for water and sediment geochemistry from upstream of the Florence urban area (&amp;#8220;blank&amp;#8221; sites) to the MC outlet (Cascine Park), passing through variably urban-impacted areas, including sites located along traffic-congested roads, close to the new tramway construction sites and under the railway line. Stream waters were sampled twice a year (June and December 2019 and 2020) to account for seasonal variability. Stream discharge at three representative points was simultaneously determined during water sampling to allow mass load calculations of contaminants. In details, major dissolved ions (Ca, Mg, Na, K, HCO&lt;sub&gt;3&lt;/sub&gt;, SO&lt;sub&gt;4&lt;/sub&gt;, Cl, NO&lt;sub&gt;3&lt;/sub&gt;) and reduced nitrogen (NH&lt;sub&gt;4&lt;/sub&gt;), trace elements (TEs: Sb, As, Cu, Zn, Cd, Co, Ba, Li, Pb, Ni) and microplastics (MPs) in stream sediments and waters of MC were determined. Major dissolved ions and NH&lt;sub&gt;4&lt;/sub&gt; were analysed via acidimetric titration and IC. TEs were determined in both sediments and waters (0.45 &amp;#956;m filtered and unfiltered) by ICP-OES and ICP-MS, respectively. MPs (1 &amp;#956;m-5 mm) were identified in sediments and waters by HD binocular stereomicroscope.&lt;/p&gt;&lt;p&gt;Chemical composition (major element constituents) of water reflected both the seasonality and the progress of the water-rock interaction acting in MC from its spring toward the outlet. In addition, the pattern of abundances of Cu, Zn, Sb and Pb and especially their mass loads reflect the increasing anthropogenic impact on the water and sediments, even if is important to stress that the contents are within the limits defined by law, except for stream sediments at a few sites. For MPs, up to 10&lt;sup&gt;9&lt;/sup&gt; particles, coming mainly from the NW side of Florence, are estimated to be discharged daily to the Arno River during the winter season, much higher than creeks with similar urbanization contexts worldwide. Increasing data collection will make it possible to identify and better understand what type of sources and processes are responsible for the anthropogenic impacts in the MC and could help in better safeguarding the creek within the framework of the urban social-ecological systems of Florence.&lt;/p&gt;
The investigation of landslides and slope deformation processes may require the integration of a ... more The investigation of landslides and slope deformation processes may require the integration of a wide range of data types, collected using different approaches, such as geomorphological, geotechnical and geophysical surveys. Among this latter category, seismic noise method can be used to detect and better understand the geometry of landslide slip surfaces. Indeed, a slip surface may generate evident contrasts in shear wave velocity due to changes in seismic impedance, generated by the different seismic velocity and density of materials at landslide boundaries. The H/V or Nakamura method allows to have a punctual information about the depth of the main impedance contrasts, thus, by performing a spatial interpolation of an adequate number of punctual depth measures, is possible to reliably estimate the depth and geometry of the slip surfaces with good accuracy. This study is focused on the relation between the number of the employed single-station seismic noise measurements and the goodness of the resulting, inferred, slip surface(s) for landslides. The final aim is to detect, if it exists, a threshold in the number of measurements beyond which the information obtained is redundant, since the variations in terms of morphology observed in the reconstructed impedance contrast surfaces become negligible. The proposed approach was validated at Castagnola Landslide (Liguria, Italy), where direct measures of the subsoil stratigraphy were available, then applied to another case study, i.e., the Roccalbegna Landslide (Tuscany, Italy), where no direct measurements, apart from those of the shallow layer geotechnical properties, were available. The experiments carried out are a proof-of-concept of the opportunities that this approach can offer.
Although terrestrial hydrothermal systems are considered among the most fascinating environments,... more Although terrestrial hydrothermal systems are considered among the most fascinating environments, how their unique and extreme conditions can affect microorganisms selection and the role in biogeochemical cycles has not yet been well elucidated. A combined geochemical and microbiological exploration in waters and sediments from ten sampling points along a sharp temperature gradient (15–90 °C) within an extremely acidic hydrothermal system (Pisciarelli Spring, Campi Flegrei area, southern Italy) displayed how hydrothermal fluids influence the microbial dynamics. This area was characterized by high levels of reduced gaseous species (e.g. H2S, H2, CH4, CO), and very low pH values (<2.3). Thermodynamic calculations revealed a high microbial catabolic potential in oxidation/reduction reactions of N-, S-, and Fe-bearing species. Overall, an increase of the archaeal/bacterial abundance ratio was observed by decreasing temperature and pH values. In particular, Archaea and Bacteria were p...
The terrestrial environment is an important contributor of microplastics (MPs) to the oceans. Urb... more The terrestrial environment is an important contributor of microplastics (MPs) to the oceans. Urban streams, strictly interwoven in the city network and to the MPs’ terrestrial source, have a relevant impact on the MP budget of large rivers and, in turn, marine areas. We investigated the fluxes (items/day) of MPs and natural fibers of Mugnone Creek, a small stream crossing the highly urbanized landscape of Florence (Italy) and ending in the Arno River (and eventually to the Tyrrhenian Sea). Measurements were done in dry and wet seasons for two years (2019–2020); stream sediments were also collected in 2019. The highest loads of anthropogenic particles were observed in the 2019 wet season (109 items/day) at the creek outlet. The number of items in sediments increased from upstream (500 items/kg) to urban sites (1540 items/kg). Fibers were the dominant shape class; they were mostly cellulosic in composition. Among synthetic items, fragments of butadiene-styrene (SBR), indicative of ti...
Carbon capture and storage (CCS) is considered a valid option to reduce the CO2 concentration in ... more Carbon capture and storage (CCS) is considered a valid option to reduce the CO2 concentration in atmosphere. The gas is collected from industrial plants, then injected and stored underground in geological reservoirs. A very wide range of information about chemical-physical characteristics of the sequestration site is therefore needed and, among them, data on porosity microstructure are crucial. Part of the processes which affect micro-porosity and act during and after the rock formation can be reconstructed by studying micro-porosity features. In this work, different experimental approaches have been combined to reconstruct the mineral association, bulk chemistry and microporous structure of rocks from a natural CO2 reservoir (which represents a natural analogue of a CCS site). The fluid reservoir, i.e. Caprese Reservoir, was discovered while drilling PSS1 borehole in San Cassiano Basin (Eastern Tuscany, Central Italy) and consists of sedimentary rocks (Burano Fm.) interbedded with altered volcanic rocks, its depth being about 3,300 m with respect to the land surface. At 3,700 m depth fluid pressure and temperature are 700 bars and 120 \ub0C respectively, with a calculated density for CO2 of 860 Kg\ub7m-3. The study was conducted on the volcanic rocks altered by CO2 from the PSS1 wellbore drill cores and on some volcanic rocks unaffected by the presence of CO2. Lastly, rocks from the Burano Formation, unavailable from PSS1, have been sampled on outcrop. Drill core samples corresponding to the depth 3,864-3,871 m with respect to PSS1 log, have been investigated with SEM-EDS, XRD, EMP, ICP-MS and LOI and for the mineralogical and chemical characterization. The SANS/VSANS experiments at LLB (Saclay, France) served for microporous structure investigation of PSS1 rocks, volcanic rocks from Eastern Alps (IG1) and the Albani Hills (IG2 and IG3) unaffected by CO2 and Burano Formation
&amp;lt;p&amp;gt;Due to their spread, abundance and potential impact on food security and... more &amp;lt;p&amp;gt;Due to their spread, abundance and potential impact on food security and human health, microplastics (MPs) are emerging global pollutants. Metropolitan areas are among the main sources of MPs (1 &amp;amp;#956;m - 5 mm); indeed, about 80% of the MPs found in the oceans come from freshwaters. In particular, impervious surfaces runoff in urban areas results in the transport of large quantities of solid wastes, comprising MPs, to the superficial water bodies. Thus, the ecological state of urban streams represents a reliable indicator to evaluate the environmental impact of a city. In this study, we report data about MPs in stream sediments and waters of a minor urban stream, the Mugnone Creek (MC), which flows across the highly urbanized city of Florence (Italy) and discharges to the Arno River.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Several sites along the 17 km-long MC were chosen, including &amp;amp;#8220;greenfield&amp;amp;#8221; sites upstream of the Florence urban area, urban-impacted sites located along congested roads, and the MC outlet. The stream sediments were collected in June 2019, while stream waters were recovered via glass bottles twice a year (June and December) in 2019 and 2020, to account for seasonal variability. Stream discharge was simultaneously determined during water sampling to allow mass flow calculations of contaminants.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Water samples were filtered onto glass microfiber filters (&amp;amp;#248; 47 mm) and observed by HD digital stereomicroscope; a similar method was followed for sediments after a density separation step (NaCl saturated solution) and H&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; digestion. Fourier Transform Infrared Spectroscopy (FT-IR) was used for identification and characterization of MPs. Microparticles classification was based on polymer type, shape and colour.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;MPs concentration in sediments showed an increasing trend from the pre-urban site to the outlet. A maximum value (1.540 MPs/kg) was reached immediately after the Terzolle Creek confluence, which drains the large University Hospital District of Careggi. Fibers were the dominant shape class of polymers observed and blue/black items stand out among the colour classes. The highest concentrations of MPs in water samples were recorded during winter seasons (up to 16.000 items/m&amp;lt;sup&amp;gt;3&amp;lt;/sup&amp;gt;), with a predominance of fibers and blue/black colours. Polymer classification by FTIR indicated the presence of (in order of abundance): PA (polyamide), PET (Polyethylene Terephthalate), SBR (butadiene-styrene rubber), PP (Polypropylene), blend PP+PE (PP+Polyethylene), PTFE (Polytetrafluoroethylene) and PU (Polyurethane). The black-SBR polymers likely related to tyre abrasion occurring during vehicles driving, since they were especially found on a site close to traffic-congested roads. In addition to synthetic particles, high concentrations of natural fibers (mainly cellulose) were found in waters at all sites. Up to 10&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt; synthetic particles are estimated to be discharged daily by MC to the Arno River during the winter season, a load much higher than creeks with similar urbanization context worldwide. Mass loads of natural fibers were of the same order of magnitude of MPs in every season.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Studies are in progress to elucidate the impact on local biota and to characterize the anthropic pressure on the Arno River, aiming to improve the knowledge about the environmental status of one of the main Italian river basins.&amp;lt;/p&amp;gt;
One of the main constraints in assessing shallow landslide hazards through physically based model... more One of the main constraints in assessing shallow landslide hazards through physically based models is the need to characterize the geotechnical parameters of the involved materials. Indeed, the quantity and quality of input data are closely related to the reliability of the results of every model used, therefore data acquisition is a critical and time-consuming step in every research activity. In this perspective, we reviewed all official certificates of tests performed through 30 years at the Geotechnics Laboratory of the Earth Science Department (University of Firenze, Firenze, Italy), compiling a dataset in which 380 points are accurately geolocated and provide information about one or more geotechnical parameters used in slope stability modeling. All tests performed in the past (in the framework of previous research programs, agreements of cooperation, or to support didactic activities) were gathered, homogenized, digitalized, and geotagged. The dataset is based on both on-site ...
Open image in new window In this work we perform an assessment of the geotechnical and hydrologic... more Open image in new window In this work we perform an assessment of the geotechnical and hydrological parameters affecting the occurrence of landslides. The aim of this study is to improve the reliability of the physically-based model HIRESSS (HIgh REsolution Slope Stability Simulator), for the forecasting of shallow landslides. The model and the soil characterization has been tested in northern Tuscany, in Italy, along the Apennine chain, an area that is historically affected by shallow landslides. In the area selected, the main geotechnical and hydrological parameters controlling the shear strength and permeability of soils have been determined by in situ measurements integrated by laboratory analyses. Around 60 survey points have been analyzed. The data obtained have been studied in order to assess the relationships existing among the different parameters and the bedrock lithology. Soil properties have been then statistically characterized and used to define the input parameters in...
&lt;p&gt;Urbanization is a striking phenomenon, responsible for the development of cities... more &lt;p&gt;Urbanization is a striking phenomenon, responsible for the development of cities as complex and highly dynamic systems. One of the most pressing issues in urban areas is water cycle management, which directly influences the availability and the quality of this resource. Urban streams are highly vulnerable to the impacts resulting from the increasing urbanization and they have often lost most of their pristine, natural character.&lt;/p&gt;&lt;p&gt;We hereby present the preliminary results of the multidisciplinary StrEams urbaN Ecological City plAnning (SENECA) project, which is not only but mainly devoted to characterizing the chemical features of stream waters and sediments of the Mugnone Creek (MC). MC is a typical example of an urban stream, crossing the city of Florence (Italy) and eventually discharging to the Arno River, that has suffered an intense denaturation due to the urban sprawl, such as several diversions, canalizations and rectifications, alterations of the stream bed and riparian habitat, widespread concrete revetment of the banks and burial of short stream tracts.&lt;/p&gt;&lt;p&gt;Different sites along the 17-km long MC were investigated for water and sediment geochemistry from upstream of the Florence urban area (&amp;#8220;blank&amp;#8221; sites) to the MC outlet (Cascine Park), passing through variably urban-impacted areas, including sites located along traffic-congested roads, close to the new tramway construction sites and under the railway line. Stream waters were sampled twice a year (June and December 2019 and 2020) to account for seasonal variability. Stream discharge at three representative points was simultaneously determined during water sampling to allow mass load calculations of contaminants. In details, major dissolved ions (Ca, Mg, Na, K, HCO&lt;sub&gt;3&lt;/sub&gt;, SO&lt;sub&gt;4&lt;/sub&gt;, Cl, NO&lt;sub&gt;3&lt;/sub&gt;) and reduced nitrogen (NH&lt;sub&gt;4&lt;/sub&gt;), trace elements (TEs: Sb, As, Cu, Zn, Cd, Co, Ba, Li, Pb, Ni) and microplastics (MPs) in stream sediments and waters of MC were determined. Major dissolved ions and NH&lt;sub&gt;4&lt;/sub&gt; were analysed via acidimetric titration and IC. TEs were determined in both sediments and waters (0.45 &amp;#956;m filtered and unfiltered) by ICP-OES and ICP-MS, respectively. MPs (1 &amp;#956;m-5 mm) were identified in sediments and waters by HD binocular stereomicroscope.&lt;/p&gt;&lt;p&gt;Chemical composition (major element constituents) of water reflected both the seasonality and the progress of the water-rock interaction acting in MC from its spring toward the outlet. In addition, the pattern of abundances of Cu, Zn, Sb and Pb and especially their mass loads reflect the increasing anthropogenic impact on the water and sediments, even if is important to stress that the contents are within the limits defined by law, except for stream sediments at a few sites. For MPs, up to 10&lt;sup&gt;9&lt;/sup&gt; particles, coming mainly from the NW side of Florence, are estimated to be discharged daily to the Arno River during the winter season, much higher than creeks with similar urbanization contexts worldwide. Increasing data collection will make it possible to identify and better understand what type of sources and processes are responsible for the anthropogenic impacts in the MC and could help in better safeguarding the creek within the framework of the urban social-ecological systems of Florence.&lt;/p&gt;
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