Separation of geochemical signals in fluvial sediments: New approaches to grain-size control and anthropogenic contamination

Álvarez-Vázquez, Miguel Ángel; Hošek, Michal; Elznicová, Jitka; Pacina, Jan; Hron, Karel; Fačevicová, Kamila; Talská, Renáta; Bábek, Ondřej; Grygar, Tomáš Matys

doi:10.1016/j.apgeochem.2020.104791

Cited by 16 publications

(6 citation statements)

References 66 publications

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“…The analytes that cannot be measured on site may be ignored during on site testing if they are found to be either significantly below thresholds or correlated with analytes that can be measured on site. The latter case is frequent, as many contaminants coexist spatially or temporally due to common contamination sources [14]. The abovementioned conformational analysis on a subset of samples allows for further verification.…”

Section: Limitations Of Near Real-time Analyses On-sitementioning

confidence: 96%

On-Site Analyses as a Decision Support Tool for Dredging and Sustainable Sediment Management

Lemière

Laperche

Wijdeveld

et al. 2022

Land

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Beneficial use of dredged sediments, either in harbours or waterways, is based on their potential as alternative resources. Such sediments can be considered as bulk materials for industrial needs, which is predicated on their current waste status or meeting end-of-waste constraints. They also can be an integral part of beneficial use projects using sediments as a bulk component, including civil engineering and landscaping. This is particularly important for beneficial use projects focusing on climate change effects mitigation, such as flood protection works, coastline defence or littoral urban areas redevelopment. When dredged sediment is used as a bulk material, its acceptability is based on an assumed homogeneity of its properties. On-site analyses allow pre-dredging detailed mapping at a denser scale than laboratory ones; monitoring dredgings during operations and during processing; and continuous control of their properties at the implementation site. This is currently possible only for a selection of inorganic analytes. When dredgings are part of a larger beneficial use project, on-site analyses facilitate first the baseline survey and the sediment source characterisation. Continuous monitoring of the sediment load allows a fast detection of contamination hot spots and their adequate management. Site survey via on-site instruments allow end users and communities to check themselves the contamination level, hence acceptability is better. On-site dredged sediment analyses monitor both building properties and environmental compliance; soil and sediment analyses at receiving sites; surface and groundwater, either for impact assessment or for monitoring works. On-site instruments provide immediate results and allow dynamic or adaptive sampling strategies, as well as allowing operational decisions in real time. Confirmation by laboratory analyses is required for validation, but on-site sample screening for laboratory analyses improves their efficiency. The present paper was developed on the basis of an earlier presentation, which it developed and updated extensively.

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Section: Limitations Of Near Real-time Analyses On-sitementioning

confidence: 96%

On-Site Analyses as a Decision Support Tool for Dredging and Sustainable Sediment Management

Lemière

Laperche

Wijdeveld

et al. 2022

Land

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“…One of the widely acknowledged difficulties in assessing flood sediment chemistry is the grain size dependence of many trace elements that are preferably found in finer sediments [14,46,127]. Hence, the grain size sorting inherent in flood sediments inevitably influences the trace element concentration [17], making correcting for textural biases imperative to compare different locations and events.…”

Section: Calculation Of a Local Geochemical Baseline And A Local Enri...mentioning

confidence: 99%

“…The evaluation of the influence of flooding on trace element concentrations is further complicated by the general complexity inherent in working with geochemical data [44][45][46]. The observed concentration of trace elements depends on the sediment's characteristics (e.g., grain size distribution and organic matter content) and, hence, cannot be interpreted directly but must be thoroughly prepared for analysis [17,[46][47][48][49]. Therefore, the direct interpretation of concentration measurements cannot provide meaningful results [47,[50][51][52].…”

Section: Introductionmentioning

confidence: 99%

Mixed response of trace element concentrations in fluvial sediments to a flash flood in a former mining area

Weber,

Lehmkuhl

2024

Environ Sci Eur

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Background Floods, especially flash floods, are the major transporting agent for fluvial sediments, whose pollution is a global concern. As floods result in the dispersion of and exposure to these sediments, a profound understanding of sedimentary dynamics during flood events and the related pollutant dispersion is of relevance. However, the characteristics of extreme flood events concerning pollutant dynamics are insufficiently known so far. Results In a Central European catchment impacted by intense industrial activities and former mining, over the course of five years, we surveyed six high-discharge events, five of them approx. bankfull discharge and one major flash flood event, supplemented by sampling of bank sediments. Fluvial sediments were analyzed for elemental composition by X-Ray fluorescence and for grain size distribution of the fine faction by laser diffraction. By applying a local enrichment factor, trace metal(loid) signatures in these sample sets were compared. Furthermore, Positive Matrix Factorization was used to investigate the trace metal(loid)s’ sources. The sediments deposited by minor flooding had continual trace metal(loid) signatures. However, for the extreme event, significant divergencies arose and persisted for the following years: The enrichment of anthropogenically influenced elements increased, with a slowly decreasing trend in the subsequent two years. Naturally dominated metal(oid)s decrease in enrichment without indicating a return to original levels. In contrast, other elements were insensitive to the extreme event. Positive Matrix Factorization identified anthropogenic influences in elements originating from copper and lead processing and mining activities. Furthermore, bed sediments and a natural background factor were found to dominate the non-anthropogenically influenced metal(loid)s. Conclusions In between extreme events, winnowing processes slowly alter the elemental composition of bed sediments. The depletion of such sediments due to the flash flood proves catchment-wide flushing, which induces a natural resetting of the geochemical signals. This ability to renew is an integral part of resilience in fluvial systems. This mechanism is disturbed by industrial activities in floodplains. The exceptional flooding reaches infrastructure that is assumed to be safe and, therefore, unprotected. These additional sources can shift flood sediments’ trace metal(loid) signature, which has a long-lasting impact on the catchment sediments. However, the modifications depend on the flooding extent, possible emitters, and protection measures.

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“…According to the IUPAC definition of a trace element, Ln-REE can be considered within this group because, in general, their contents are below 100 mg kg −1 . Between the many techniques developed to estimate the background of trace elements [11,12], the calculation of background functions using a reference (conservative) element at the local scale is recommended [25,36].…”

Section: Background Estimation and Environmental Assessmentmentioning

confidence: 99%

Patterns and Abundance of Rare Earth Elements in Sediments of a Bedrock River (Miño River, NW Iberian Peninsula)

2022

Self Cite

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Bedrock rivers, whose sedimentary geochemistry has been scarcely investigated, are suitable to test geochemical approaches in order to assess the existence and extent of human alterations in the natural abundance of rare earth elements. This work presents the study of REE contents in fine-grained sediments of the (bedrock) Miño River, in an urban reach of its middle course. Different statistical procedures were employed in order to decipher the abundances and patterns of distribution of REE in different environments, showing a higher REE accumulation in surface sediments trapped by potholes and other rock cavities. Background contents were estimated by iterative simple regression. After checking several possible reference elements, Y showed the highest potential for the series of REE from La to Lu. The regression result, namely background function, is very useful to minimize the effect of the natural variability in sediment contents. Background functions also allow for environmental assessment by the calculation of the so-called local enrichment factors. As a general conclusion, contamination, if it exists, is negligible in the area and low enrichments can be attributed to postdepositional processes related to organic matter and the geochemistry of Fe and Mn.

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Separation of geochemical signals in fluvial sediments: New approaches to grain-size control and anthropogenic contamination

Cited by 16 publications

References 66 publications

On-Site Analyses as a Decision Support Tool for Dredging and Sustainable Sediment Management

On-Site Analyses as a Decision Support Tool for Dredging and Sustainable Sediment Management

Mixed response of trace element concentrations in fluvial sediments to a flash flood in a former mining area

Patterns and Abundance of Rare Earth Elements in Sediments of a Bedrock River (Miño River, NW Iberian Peninsula)

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