Guiding principles for the development and application of solid-phase phosphorus adsorbents for freshwater ecosystems

While a diverse array of phosphorus (P)-adsorbent materials is currently available for application to freshwater aquatic systems, selection of the most appropriate P-adsorbents remains problematic. In particular, there has to be a close correspondence between attributes of the P-adsorbent, its field performance, and the management goals for treatment. These management goals may vary from a rapid reduction in dissolved P to address seasonal enrichments from internal loading, targeting external fluxes due to anthropogenic sources, or long term inactivation of internal P inventories contained within bottom sediments. It also remains a challenge to develop new methods and materials that are ecologically benign and cost-effective. We draw on evidence in the literature and the authors’ personal experiences in the field, to summarise the attributes of a range of P-adsorbent materials. We offer 'guiding principles' to support practical use of existing materials and outline key development needs for new materials

Kinetic monitoring of trisubstituted organotins in soil after sewage sludge application

cited By 3International audienceOrganotin compounds (OTC) are widely used for their biocidal effects in various agricultural or industrial activities, leading to their environmental presence. Among the organotin species, tributyltin (TBT) and triphenyltin (TPhT) are the most used and are generally considered the most toxic. So it is important to understand their behaviour in soils and obtain data about their persistence and phytoavailability. Many works deal with OTC speciation in various matrices, but few are concerned with OTC degradation in soil. The present study focuses on kinetic monitoring of TBT and TPhT in an agricultural soil. These compounds were introduced into the soil by the way of spiked sewage sludge, simulating agricultural practice and diffuse contamination. The influence of time and initial OTC concentration on the species preservation was evaluated. TBT concentration was shown to have a positive effect on TBT preservation. Corresponding half-lives were calculated. They were 6 ± 1 days and over 39 days for TPhT and TBT, respectively. Degradation compounds, mono- and dibutyltin, and mono- and diphenyltin, were produced by both direct and successive dealkyl and dearylation processes. Copyright © 2008 John Wiley & Sons, Ltd

Zn and Cd uptake by Lettuca sativa depending on pH in soils contaminated by industrial dust fallout

International audienc

Mineral micro- and nano-variability revealed by combined micromorphology and in situ submicroscopy

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Transmission x-ray diffraction of undisturbed soil microfabrics obtained by microdrilling in thin sections

Clay mineralogical studies by X-ray diffraction performed on extracted <2-μm fractions do not always represent all clay mineral constituents present in the soil. In this work, transmission X-ray diffraction (TXRD) was applied to undisturbed microsamples of optically homogeneous mineral soil fabrics and features. These microsamples were isolated by microdrilling their periphery in soil thin sections, then removing them, and transferring them to glass capillaries for TXRD analysis. The usefulness of this technique for supplying in situ mineralogical information on identification, structure, and natural orientation of soil constituents was tested on mineral microfabrics and features of primary and secondary phyllosilicates. The study demonstrated that TXRD allowed detailed, representative interpretations of undisturbed mineral features and fabrics. In particular, this technique allowed us (1) to compare mineralogical compositions at selected microlocalities, (2) to study natural preferred orientations, and (3) to detect small amounts of minor mineral interstratification phases. In addition, complementary information on crystallography and crystal chemistry may be obtained by performing analytical transmission electron microscopy on the same microsample. | Clay mineralogical studies by X-ray diffraction performed on extracted <2-μm fractions do not always represent all clay mineral constituents present in the soil. In this work, transmission X-ray diffraction (TXRD) was applied to undisturbed microsamples of optically homogeneous mineral soil fabrics and features. These microsamples were isolated by microdrilling their periphery in soil thin sections, then removing them, and transferring them to glass capillaries for TXRD analysis. The usefulness of this technique for supplying in situ mineralogical information on identification, structure, and natural orientation of soil constituents was tested on mineral microfabrics and features of primary and secondary phyllosilicates. The study demonstrated that TXRD allowed detailed, representative interpretations of undisturbed mineral features and fabrics. In particular, this technique allowed us (1) to compared mineralogical compositions at selected microlocalities, (2) to study natural preferred orientations, and (3) to detect small amounts of minor mineral interstratification phases. In addition, complementary information on crystallography and crystal chemistry may be obtained by performing analytical transmission electron microscopy on the same microsample