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3 resultados encontrados para: AUTOR: Ritsema, Coen J
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1.
- Artículo con arbitraje
Leaching of microplastics by preferential flow in earthworm (Lumbricus terrestris) burrows
Yu, Miao (autor) ; van der Ploeg, Martine (autora) ; Huerta Lwanga, Esperanza (autora) ; Yang, Xiaomei (autora) ; Zhang, Shaoliang (autor) ; Ma, Xiaoyi (autora) ; Ritsema, Coen J. (autor) ; Geissen Geissen, Violette (autora) ;
Disponible en línea
Contenido en: Environmental Chemistry Vol. 16, no. 1 (January 2019), p. 31-40 ISSN: 1448-2517
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Resumen en: Inglés |
Resumen en inglés

In the current study, we examine how the activities of earthworms (Lumbricus terrestris) affect microplastic (MP) distribution and concentration in soil, with a focus on low density polyethylene (LDPE). We also want to determine if MPs can be flushed out with water. We used a laboratory sandy soil column (polyvinyl chloride tube) experimental set-up and tested five different treatments: (1) treatment with just soil (control) to check if the saturated conductivity (Ksat) could be impacted by MP, (2) treatment with MP, (3) treatment with MP and litter, (4) treatment with earthworms and litter as a second control for treatment 5 and (5) treatment with MPs, earthworms and litter. Each treatment consisted of eight replicates. For the treatments with MP, the concentration of MP added at the start of the experiment was 7 % by weight (3.97 g, polyethylene, 50 % 1 mm–250 µm, 30 % 250 µm–150 µm and 20 % <150 µm) based on 52.78 g of dry litter from Populus nigra. In the treatments using earthworms, two adult earthworms, with an initial average weight of (7.14 ± 0.26) g, were placed in each column. Results showed that LDPE particles could be introduced into the soil by the earthworms.

MP particles were detected in each soil sample and within different soil layers for the earthworm treatments. Earthworms showed a tendency to transport the smaller MP particles and that the amount of MPs in size class <250 μm increased in soil samples with increasing soil depth in comparison to the other size classes. After leaching, MPs were only detected in the leachate from the treatments with the earthworms, and the MP had similar size distributions as the soil samples in the 40–50 cm layer of the treatment with MP, earthworms and litter. The results of this study clearly show that biogenic activities can mobilise MP transport from the surface into the soil and even be leached into drainage. It is highly likely that biogenic activities constitute a potential pathway for MPs to be transported into soil and groundwater.


2.
- Artículo con arbitraje
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A framework approach for unravelling the impact of multiple factors influencing flooding
Gai, Lingtong (autora) ; Baartman, Jantiene E. M. (autora) ; Mendoza Carranza, Manuel (autor) ; Wang, Feng (autor) ; Ritsema, Coen J. (autor) ; Geissen Geissen, Violette (autora) ;
Disponible en línea
Contenido en: Journal of Flood Risk Management Vol. 11 (2018), p. 111-126 ISSN: 1753-318X
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Resumen en: Inglés |
Resumen en inglés

To have a better understanding of the in fluence of topographic, climatic, and, especially, anthropogenic factors on hydrological discharge and flooding, this study proposes a new framework approach using a set of methods to answer the questions why, where, when, and how flooding occurs. Including conditional inference tree (CIT), cross-correlation, and double-mass curves analysis, the approach is demonstrated in an application to the Wei River Basin, China. From the CIT analysis, dam construction period was identified as the most important factor (why), and the sub-catchment farthest upstream contributed the most to the flooding of the downstream floodplain (where). We then analysed the effect of the periods of dam construction on the time lag change (when) and the precipitation – discharge relationship (how) using cross-correlation analysis and double-mass curves analysis, respectively. The results suggested that the dam construction delayed the precipitation for 0.4 days on average compared to before the dam construction period, and the discharge at the outlet of the basin was reduced by 44%. This framework approach is promising as it can quantitatively evaluate the importance of multiple factors on multiple years of flooding, while many studies evaluate single flooding events.


3.
- Artículo con arbitraje
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Influence of microplastic addition on glyphosate decay and soil microbial activities in Chinese loess soil
Yang, Xiaomei ; Bento, Célia P.M. (coaut.) ; Chen, Hao (coaut.) ; Zhang, Hongming (coaut.) ; Xue, Sha (coaut.) ; Huerta Lwanga, Esperanza (coaut.) ; Zomer, Paul (coaut.) ; Ritsema, Coen J. (coaut.) ; Geissen Geissen, Violette (coaut.) ;
Contenido en: Environmental Pollution Vol. 242, Part A (November 2018), p. 338-347 ISSN: 0269-7491
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Resumen en: Inglés |
Resumen en inglés

The intensive use of pesticide and plastic mulches has considerably enhanced crop growth and yield. Pesticide residues and plastic debris, however, have caused serious environmental problems. This study investigated the effects of the commonly used herbicide glyphosate and micrometre-sized plastic debris, referred as microplastics, on glyphosate decay and soil microbial activities in Chinese loess soil by a microcosm experiment over 30 days incubation. Results showed that glyphosate decay was gradual and followed a single first-order decay kinetics model. In different treatments (with/without microplastic addition), glyphosate showed similar half-lives (32.8 days). The soil content of aminomethylphosphonic acid (AMPA), the main metabolite of glyphosate, steadily increased without reaching plateau and declining phases throughout the experiment. Soil microbial respiration significantly changed throughout the entirety of the experiment, particularly in the treatments with higher microplastic addition. The dynamics of soil β-glucosidase, urease and phosphatase varied, especially in the treatments with high microplastic addition. Particles that were considerably smaller than the initially added microplastic particles were observed after 30 days incubation. This result thus implied that microplastic would hardly affect glyphosate decay but smaller plastic particles accumulated in soils which potentially threaten soil quality would be further concerned especially in the regions with intensive plastic mulching application.