61 results on '"Rees, Frédéric"'
Search Results
52. Short-term effects of biochar on soil heavy metal mobility are controlled by intra-particle diffusion and soil pH increase
- Author
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Rees, Frédéric, Simonnot, Marie-Odile, Morel, Jean-Louis, Laboratoire Sols et Environnement (LSE), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Sols et Eaux, Laboratoire Réactions et Génie des Procédés (LRGP), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), French Lorraine Region, and ERDF
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lead ,greenwaste compost ,sorption ,cadmium ,adsorption ,[SDE.IE]Environmental Sciences/Environmental Engineering ,removal ,ZN ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,bioavailability ,complex mixtures ,PB ,CD - Abstract
International audience; Biochar, the solid product of biomass pyrolysis, can be used as a soil amendment to stabilize metals in contaminated soils. The effects of biochar on the mobility of metals in soils are, however, poorly understood. To identify the predominant processes, we focused on (i) a possible kinetic limitation by transport in biochar particles, (ii) the evolution of biochar mineral phases and (iii) the effect of biochar on soil pH. Batch experiments were conducted to measure the sorption kinetics of copper (Cu), cadmium (Cd) and nickel (Ni) and the sorption-desorption isotherms for lead (Pb), Cu, Cd, zinc (Zn) and Ni in a wood-derived biochar. Sorption data were then compared with extraction test results using biochar with one acidic and one basic soil contaminated by Zn, Cd and Pb. Kinetic results showed that biochar particle sizes controlled metal sorption rate despite a similar specific surface area, which indicated a limitation by intra-particle diffusion. Isotherms showed a partially reversible sorption to biochar following the order Pb>Cu>Cd≥Zn>Ni, which we explained primarily by the (co)precipitation of metals or their adsorption on specific biochar mineral phases. Effective metal immobilization was observed with biochar in both contaminated soils but could not be predicted from the sorption isotherms. This immobilization appeared to be governed by the soil pH increase, which induced a greater retention of metals on soil particles. Short-term effects of biochar on contaminated soils may therefore be controlled by diffusion in biochar particles and by soil alkalinization processes.
- Published
- 2013
53. Localization of heavy metals immobilized on specific organic and mineral parts of a wood-derived biochar
- Author
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REES, Frédéric, Watteau, Françoise, Morel, Jean-Louis, Laboratoire Sols et Environnement (LSE), and Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL)
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[SDV]Life Sciences [q-bio] ,[SDE]Environmental Sciences - Abstract
International audience; Biochar has been intensively investigated over recent years, not only as a promising carbon sequestration or fertilizing agent in soils but also as a possible new sorbent to remediate contaminated soils. A few studies have revealed its high potential for heavy metals immobilization depending on the nature of biochar and trace elements. The mechanisms behind this immobilization remain however unclear: some authors have hypothesized a high sorption capacity due to biochar large surface area while others have suggested that this immobilization is mainly due to soil pH increase. In particular, the distinction between heavy metals specific sorption in biochar pores and heavy metals precipitation in or outside biochar particles is often impossible to make while it is of primary importance to evaluate biochar ability to retain these pollutants on a long-time scale. In order to evaluate the main heavy metal immobilization effects on a standard biochar and to identify the most successful biochar parts of the sample, we examined biochar particles after heavy metals immobilization in batch experiments designed to mimic real chemical processes in soils. A biochar derived from hard and soft wood and pyrolyzed at about 450°C was put in contact with relatively low concentrations of heavy metals (Pb, Cu, Cd, Zn, Ni) in an initially acidic Ca(NO3)2 solution. Following a one-week adsorption and a one-week desorption step, we recovered the biochar particles and observed them using scanning electron microscopy coupled to energy dispersive x-ray spectroscopy, focusing especially on the changes in mineral phases and the location of each of the retained heavy metals on biochar particles. We were able to distinguish different structures in the biochar samples which were linked to the degree of pyrolysis and the exact nature of the raw wood biomass. We detected the presence of concentrated metals zones (e.g. lead) in specific locations of the organic particles depending on the original plant tissues, and enlightened metal associations with newly-formed mineral phases such as calcite present on biochar surface. These observations provide new insights in the understanding of metal immobilization mechanisms on biochar such as precipitation and co-precipitation. Our findings also underline the need to consider the heterogeneity of biochar constitution for optimizing the remediation potential of biochar on contaminated sites.
- Published
- 2013
54. Long-term effects assessment of biochar to remediate heavy-metals contaminated soils
- Author
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REES, Frédéric, Morel, Jean-Louis, Simonnot, Marie-Odile, Laboratoire Sols et Environnement (LSE), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Laboratoire Réactions et Génie des Procédés (LRGP), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and Centre de Microbiologie du Sol et de l'Environnement (CMSE). FRA.
- Subjects
[SDV]Life Sciences [q-bio] ,[SDE]Environmental Sciences - Abstract
National audience; Biochar, the residual solid of biomass pyrolysis, has recently drained considerable attention as a potential carbon sequestration agent in soils due to its high recalcitrance to biodegradation as long as a low-cost soil quality improver to increase plant growth 1. Recent studies suggest also biochar ability to immobilize heavy metals in soils and thus to reduce the toxic impact of these elements 2–4. However, the sorption mechanisms and reversibility degree of biochar effects for the remediation of contaminated soils are still unclear and must be addressed to evaluate potential risks of biochar use in these soils5. In a first attempt to evaluate biochar capacity to immobilize metals in solution, we set up batch sorption studies of cationic trace elements (Cu, Cd, Ni, Zn, Pb) on an alkaline biochar produced at about 450°C from conifers and deciduous wood. Kinetics results show that sorption speed is low and particles-size dependent, which may be attributed to limiting diffusion of metal inside biochar particles. Adsorption/desorption experiments with initial metal concentration of 10-500 μmol/L reveal different sorption trends depending on the elements: Freundlich-type isotherms of Cd and Zn are identical while Cu and Pb show a much higher affinity for biochar and Ni the lowest of all five elements. On the other hand, hysteresis with desorption isotherms reveal a marked sorption irreversibility especially for Cu and Pb. However, the sorption dynamics of heavy-metals on biochar remains complex and several environmental parameters have to be taken into account, e.g. the influence of pH variations of the system in order to mimic possible long-term acidification of contaminated soils amended with biochar. In a second time, we will discuss the results of continuous solution analysis in column experiments with biochar alone and biochar-amended contaminated soils leached with different extracting solutions to describe the actual sorption dynamics on biochar of heavy-metals originating from historical atmospheric pollution by smelters in order to assess biochar potential for long-term remediation of contaminated sites.
- Published
- 2012
55. Immobilization mechanisms of heavy metals in contaminated soils with biochar amendments
- Author
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REES, Frédéric, Simonnot, Marie-Odile, Morel, Jean-Louis, Laboratoire Sols et Environnement (LSE), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Laboratoire Réactions et Génie des Procédés (LRGP), and Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)
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[SDV]Life Sciences [q-bio] ,[SDE]Environmental Sciences ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2012
56. Intéractions entre biochar et métaux lourds dans les systèmes sol-plante
- Author
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REES, Frédéric, Morel, Jean-Louis, Laboratoire Sols et Environnement (LSE), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), and Ecole Doctorale Sciences et Ingénierie, Procédés, Produits et Environnement (RP2E). FRA.
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[SDV]Life Sciences [q-bio] ,[SDE]Environmental Sciences ,ComputingMilieux_MISCELLANEOUS - Abstract
National audience
- Published
- 2012
57. Biochars in soils: towards the required level of scientific understanding.
- Author
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Tammeorg, Priit, Bastos, Ana Catarina, Jeffery, Simon, Rees, Frédéric, Kern, Jürgen, Graber, Ellen R., Ventura, Maurizio, Kibblewhite, Mark, Amaro, António, Budai, Alice, Cordovil, Cláudia M. d. S., Domene, Xavier, Gardi, Ciro, Gascó, Gabriel, Horák, Ján, Kammann, Claudia, Kondrlova, Elena, Laird, David, Loureiro, Susana, and Martins, Martinho A. S.
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BIOCHAR -- Environmental aspects ,SUSTAINABLE development ,SOIL remediation - Abstract
Key priorities in biochar research for future guidance of sustainable policy development have been identified by expert assessment within the COST Action TD1107. The current level of scientific understanding (LOSU) regarding the consequences of biochar application to soil were explored. Five broad thematic areas of biochar research were addressed: soil biodiversity and ecotoxicology, soil organic matter and greenhouse gas (GHG) emissions, soil physical properties, nutrient cycles and crop production, and soil remediation. The highest future research priorities regarding biochar’s effects in soils were: functional redundancy within soil microbial communities, bioavailability of biochar’s contaminants to soil biota, soil organic matter stability, GHG emissions, soil formation, soil hydrology, nutrient cycling due to microbial priming as well as altered rhizosphere ecology, and soil pH buffering capacity. Methodological and other constraints to achieve the required LOSU are discussed and options for efficient progress of biochar research and sustainable application to soil are presented. [ABSTRACT FROM PUBLISHER]
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- 2017
- Full Text
- View/download PDF
58. Bypass and hyperbole in soil science: A perspective from the next generation of soil scientists
- Author
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Portell, Xavier, Sauzet, Ophélie, Balseiro‐Romero, María, Benard, Pascal, Cardinael, Rémi, Couradeau, Estelle, Danra, Dieudonné D., Evans, Daniel L., Fry, Ellen L., Hammer, Edith C., Mamba, Danielle, Merino‐Martín, Luis, Mueller, Carsten W., Paradelo, Marcos, Rees, Frédéric, Rossi, Lorenzo, Schmidt, Hannes, Schnee, Laura S., Védère, Charlotte, and Vidal, Alix
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13. Climate action - Abstract
European Journal of Soil Science, 72 (1), ISSN:1351-0754, ISSN:1365-2389
59. A possible trade-off between soil nitrogen availability and root carbon inputs to soil
- Author
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Rees, Frédéric, Chenu, Claire, Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS), and Institut National de la Recherche Agronomique (INRA)-AgroParisTech
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[SDV]Life Sciences [q-bio] ,[SDE]Environmental Sciences - Abstract
The potential of agricultural soils to store carbon (C) has been claimed to require a large amount of nitrogen (N) and therefore a high soil N availability. This assumption is based on the observation that stable soil organic compounds are characterized by a narrow range in C:N ratios. However, N-fertilizer additions have also been shown to increase respiratory C losses from soils. Furthermore, most of the organic C naturally stored in soils originate from plant C inputs, which occur both by aerial litter deposition and by root turnover and rhizodeposition. Root C inputs have been shown to contribute 2-3 times more to soil C sequestration than shoot-derived C inputs. However, root C inputs may be limited or even decrease when soil N availability increases beyond a certain level. A trade-off may therefore exist between the amount of soil available N and the potential of soil C sequestration associated to the inputs of root C. The existence of such trade-off and its possible consequences for the optimization of soil C sequestration will be discussed according to evidences from scientific literature and to a modelling approach describing how root C inputs to soil can evolve with soil N availability.
60. Microbial response to carbon and nutrient additions in boreal forest soils and coversoils used during post-mining reclamation
- Author
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Lejoly, Justine, Quideau, Sylvie A., and Rees, Frédéric
- Published
- 2019
- Full Text
- View/download PDF
61. Can N 2 O emissions offset the benefits from soil organic carbon storage?
- Author
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Guenet B, Gabrielle B, Chenu C, Arrouays D, Balesdent J, Bernoux M, Bruni E, Caliman JP, Cardinael R, Chen S, Ciais P, Desbois D, Fouche J, Frank S, Henault C, Lugato E, Naipal V, Nesme T, Obersteiner M, Pellerin S, Powlson DS, Rasse DP, Rees F, Soussana JF, Su Y, Tian H, Valin H, and Zhou F
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- Agriculture, Carbon analysis, Nitrous Oxide analysis, Paris, Greenhouse Gases, Soil
- Abstract
To respect the Paris agreement targeting a limitation of global warming below 2°C by 2100, and possibly below 1.5°C, drastic reductions of greenhouse gas emissions are mandatory but not sufficient. Large-scale deployment of other climate mitigation strategies is also necessary. Among these, increasing soil organic carbon (SOC) stocks is an important lever because carbon in soils can be stored for long periods and land management options to achieve this already exist and have been widely tested. However, agricultural soils are also an important source of nitrous oxide (N
2 O), a powerful greenhouse gas, and increasing SOC may influence N2 O emissions, likely causing an increase in many cases, thus tending to offset the climate change benefit from increased SOC storage. Here we review the main agricultural management options for increasing SOC stocks. We evaluate the amount of SOC that can be stored as well as resulting changes in N2 O emissions to better estimate the climate benefits of these management options. Based on quantitative data obtained from published meta-analyses and from our current level of understanding, we conclude that the climate mitigation induced by increased SOC storage is generally overestimated if associated N2 O emissions are not considered but, with the exception of reduced tillage, is never fully offset. Some options (e.g. biochar or non-pyrogenic C amendment application) may even decrease N2 O emissions., (© 2020 John Wiley & Sons Ltd.)- Published
- 2021
- Full Text
- View/download PDF
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