Lead migration in smelter-impacted deciduous and coniferous organic soil horizons based on a long-term in-situ implantation and laboratory column experiments

Hydrothermally altered rocks generated from underground/tunnel projects often produce acidic leachate and release heavy metals and toxic metalloids, such as arsenic (As). The adsorption layer and immobilization methods using natural adsorbents or immobilizer as reasonable countermeasures have been proposed. In this study, two sets of column experiments were conducted, of which one was focused on the laboratory columns and other on the in situ columns, to evaluate the effects of column conditions on leaching of As from excavated rocks and on adsorption or immobilization behavior of As by a river sediment (RS) as a natural adsorbent or immobilizer. A bottom adsorption layer consisting of the RS was constructed under the excavated rock layer or a mixing layer of the excavated rock and river sediment was packed in the column. The results showed that no significant trends in the adsorption and immobilization of As by the RS were observed by comparing laboratory and in situ column experiments because the experimental conditions did not influence significant change in the leachate pH which affects As adsorption or immobilization. However, As leaching concentrations of the in situ experiments were higher than those of the laboratory column experiments. In addition, the lower pH, higher Eh and higher coexisting sulfate ions of the leachate were observed for the in situ columns, compared to the results of the laboratory columns. These results indicate that the leaching concentration of As became higher in the in situ columns, resulting in higher oxidation of sulfide minerals in the rock. This may be due to the differences in conditions, such as temperature and water content, which induce the differences in the rate of oxidation of minerals contained in the rock. On the other hand, since the leachate pH affecting As adsorption or immobilization was not influenced significantly, As adsorption or immobilization effect by the RS were effective for both laboratory and in situ column experiments. These results indicate that both in situ and laboratory column experiments are useful in evaluating leaching and adsorption of As by natural adsorbents, despite the fact that the water content which directly affects the rate of oxidation is sensitive to weathering conditions.

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Modeling long term Enhanced in situ Biodenitrification and induced heterogeneity in column experiments under different feeding strategies

Journal of Hydrology ◽

10.1016/j.jhydrol.2016.04.012 ◽

2016 ◽

Vol 538 ◽

pp. 127-137 ◽

Cited By ~ 11

Author(s):

Paula Rodríguez-Escales ◽

Albert Folch ◽

Boris M. van Breukelen ◽

Georgina Vidal-Gavilan ◽

Xavier Sanchez-Vila

Keyword(s):

Feeding Strategies ◽

Column Experiments

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Efficiency of end effect probes for in-situ permittivity measurements in the 0.5–6GHz frequency range and their application for organic soil horizons study

Sensors and Actuators A Physical ◽

10.1016/j.sna.2016.12.005 ◽

2017 ◽

Vol 254 ◽

pp. 78-88 ◽

Cited By ~ 10

Author(s):

François Demontoux ◽

Stephen Razafindratsima ◽

Simone Bircher ◽

Gilles Ruffié ◽

Fabrice Bonnaudin ◽

...

Keyword(s):

Organic Soil ◽

Frequency Range ◽

End Effect ◽

Soil Horizons ◽

Permittivity Measurements

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Laboratory column experiments and transport modeling to evaluate retardation of uranium in an aquifer downgradient of a uranium in-situ recovery site

Applied Geochemistry ◽

10.1016/j.apgeochem.2017.02.018 ◽

2017 ◽

Vol 80 ◽

pp. 1-13 ◽

Cited By ~ 14

Author(s):

Martin A. Dangelmayr ◽

Paul W. Reimus ◽

Naomi L. Wasserman ◽

Jesse J. Punsal ◽

Raymond H. Johnson ◽

...

Keyword(s):

Transport Modeling ◽

Column Experiments ◽

Laboratory Column ◽

In Situ Recovery

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Global soil moisture data derived through machine learning trained with in-situ measurements

Scientific Data ◽

10.1038/s41597-021-00964-1 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Sungmin O. ◽

Rene Orth

Keyword(s):

Machine Learning ◽

Soil Moisture ◽

Large Scale ◽

Short Term Memory ◽

Temporal Dynamics ◽

Soil Moisture Data ◽

Wide Range ◽

Global Soil

AbstractWhile soil moisture information is essential for a wide range of hydrologic and climate applications, spatially-continuous soil moisture data is only available from satellite observations or model simulations. Here we present a global, long-term dataset of soil moisture derived through machine learning trained with in-situ measurements, SoMo.ml. We train a Long Short-Term Memory (LSTM) model to extrapolate daily soil moisture dynamics in space and in time, based on in-situ data collected from more than 1,000 stations across the globe. SoMo.ml provides multi-layer soil moisture data (0–10 cm, 10–30 cm, and 30–50 cm) at 0.25° spatial and daily temporal resolution over the period 2000–2019. The performance of the resulting dataset is evaluated through cross validation and inter-comparison with existing soil moisture datasets. SoMo.ml performs especially well in terms of temporal dynamics, making it particularly useful for applications requiring time-varying soil moisture, such as anomaly detection and memory analyses. SoMo.ml complements the existing suite of modelled and satellite-based datasets given its distinct derivation, to support large-scale hydrological, meteorological, and ecological analyses.

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A Study of UVER in Santiago, Chile Based on Long-Term In Situ Measurements (Five Years) and Empirical Modelling

Energies ◽

10.3390/en14020368 ◽

2021 ◽

Vol 14 (2) ◽

pp. 368

Author(s):

Lisdelys González-Rodríguez ◽

Amauri Pereira de Oliveira ◽

Lien Rodríguez-López ◽

Jorge Rosas ◽

David Contreras ◽

...

Keyword(s):

Urban Areas ◽

Solar Spectrum ◽

Sun Exposure ◽

Great Accuracy ◽

In Situ Measurements ◽

Uv Index ◽

Empirical Modelling ◽

The People

Ultraviolet radiation is a highly energetic component of the solar spectrum that needs to be monitored because is harmful to life on Earth, especially in areas where the ozone layer has been depleted, like Chile. This work is the first to address the long-term (five-year) behaviour of ultraviolet erythemal radiation (UVER) in Santiago, Chile (33.5° S, 70.7° W, 500 m) using in situ measurements and empirical modelling. Observations indicate that to alert the people on the risks of UVER overexposure, it is necessary to use, in addition to the currently available UV index (UVI), three more erythema indices: standard erythemal doses (SEDs), minimum erythemal doses (MEDs), and sun exposure time (tery). The combination of UVI, SEDs, MEDs, and tery shows that in Santiago, individuals with skin types III and IV are exposed to harmfully high UVER doses for 46% of the time that UVI indicates is safe. Empirical models predicted hourly and daily values UVER in Santiago with great accuracy and can be applied to other Chilean urban areas with similar climate. This research inspires future advances in reconstructing large datasets to analyse the UVER in Central Chile, its trends, and its changes.

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In-Situ Annealed Ti3C2Tx MXene Based All-Solid-State Flexible Zn-Ion Hybrid Micro Supercapacitor Array with Enhanced Stability

Nano-Micro Letters ◽

10.1007/s40820-021-00634-2 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

La Li ◽

Weijia Liu ◽

Kai Jiang ◽

Di Chen ◽

Fengyu Qu ◽

...

Keyword(s):

High Energy ◽

High Rate ◽

High Energy Density ◽

Electrochemical Performances ◽

Integrated Electronics ◽

Long Term Stability ◽

Hybrid Supercapacitors ◽

Portable Electronics

AbstractZn-ion hybrid supercapacitors (SCs) are considered as promising energy storage owing to their high energy density compared to traditional SCs. How to realize the miniaturization, patterning, and flexibility of the Zn-ion SCs without affecting the electrochemical performances has special meanings for expanding their applications in wearable integrated electronics. Ti3C2Tx cathode with outstanding conductivity, unique lamellar structure and good mechanical flexibility has been demonstrated tremendous potential in the design of Zn-ion SCs, but achieving long cycling stability and high rate stability is still big challenges. Here, we proposed a facile laser writing approach to fabricate patterned Ti3C2Tx-based Zn-ion micro-supercapacitors (MSCs), followed by the in-situ anneal treatment of the assembled MSCs to improve the long-term stability, which exhibits 80% of the capacitance retention even after 50,000 charge/discharge cycles and superior rate stability. The influence of the cathode thickness on the electrochemical performance of the MSCs is also studied. When the thickness reaches 0.851 µm the maximum areal capacitance of 72.02 mF cm−2 at scan rate of 10 mV s−1, which is 1.77 times higher than that with a thickness of 0.329 µm (35.6 mF cm−2). Moreover, the fabricated Ti3C2Tx based Zn-ion MSCs have excellent flexibility, a digital timer can be driven by the single device even under bending state, a flexible LED displayer of “TiC” logo also can be easily lighted by the MSC arrays under twisting, crimping, and winding conditions, demonstrating the scalable fabrication and application of the fabricated MSCs in portable electronics.

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A long-term, gridded, subsurface physical oceanography dataset and average annual cycles derived from in situ measurements off the Western Australia coast during 2009–2020

Data in Brief ◽

10.1016/j.dib.2021.106812 ◽

2021 ◽

Vol 35 ◽

pp. 106812

Author(s):

Miaoju Chen ◽

Ming Feng

Keyword(s):

Western Australia ◽

In Situ Measurements ◽

Physical Oceanography ◽

Annual Cycles

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