The Seashell Wastes as Biosorbent for Reactive Dye Removal from Textile Effluents     

Daniela Suteu  Doina Bilba  Magdalena Aflori  Florica Doroftei  Gabriela Lisa  Marinela Badeanu  Teodor Malutan 《洁净——土壤、空气、水》2012,40(2):198-205

This study investigates structural and adsorption properties of the powdered waste shells of Rapana gastropod and their use as a new cheap adsorbent to remove reactive dye Brilliant Red HE‐3B from aqueous solutions under batch conditions. For the powder shells characterization, solubility tests in acidic solutions and X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDX), Fourier transform IR spectroscopy (FT‐IR) and thermogravimetric analyses were performed. The results revealed that the adsorbent surface is heterogeneous consisting mainly from calcium carbonate layers (either calcite or aragonite) and a small amount of organic macromolecules (proteins and polysaccharides). The dye adsorptive potential of gastropod shells powder was evaluated as function of initial solution pH (1–5), adsorbent dose (6–40 g L^?1), dye concentration (50–300 mg L^?1), temperature (5–60°C), and contact time (0–24 h). It was observed that the maximum values of dye percentage removal were obtained at the initial pH of solution 1.2, shells dose of 40 g L^?1, dye initial concentration of 50–50 mg L^?1 and higher temperatures; the equilibrium time decreases with increasing of dye concentration. It is proved that the waste seashell powder can be used as low cost bioinorganic adsorbent for dyes removal from textile wastewaters.  相似文献   

Assessing the results of scenarios of climate and land use changes on the hydrology of an Italian catchment: modelling study   总被引：1，自引：0，他引：1  

Daniela R. D'Agostino  Liuzzi Giuliana Trisorio  Nicola Lamaddalena  Ragab Ragab 《水文研究》2010,24(19):2693-2704

Hydrological models are recognized as valid scientific tools to study water quantity and quality and provide support for the integrated management and planning of water resources at different scales. In common with many catchments in the Mediterranean, the study catchment has many problems such as the increasing gap between water demand and supply, water quality deterioration, scarcity of available data, lack of measurements and specific information. The application of hydrological models to investigate hydrological processes in this type of catchments is of particular relevance for water planning strategies to address the possible impact of climate and land use changes on water resources. The distributed catchment scale model (DiCaSM) was selected to study the impact of climate and land use changes on the hydrological cycle and the water balance components in the Apulia region, southern Italy, specifically in the Candelaro catchment (1780 km²). The results obtained from this investigation proved the ability of DiCaSM to quantify the different components of the catchment water balance and to successfully simulate the stream flows. In addition, the model was run with the climate change scenarios for southern Italy, i.e. reduced winter rainfall by 5–10%, reduced summer rainfall by 15–20%, winter temperature rise by 1·25–1·5 °C and summer temperature rise by 1·5–1·75 °C. The results indicated that by 2050, groundwater recharge in the Candelaro catchment would decrease by 21–31% and stream flows by 16–23%. The model results also showed that the projected durum wheat yield up to 2050 is likely to decrease between 2·2% and 10·4% due to the future reduction in rainfall and increase in temperature. In the current study, the reliability of the DiCaSM was assessed when applied to the Candelaro catchment; those parameters that may cause uncertainty in model output were investigated using a generalized likelihood uncertainty estimation (GLUE) methodology. The results showed that DiCaSM provided a small level of uncertainty and subsequently, a higher confidence level. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

New challenges in integrated water quality modelling   总被引：1，自引：0，他引：1  

Michael Rode  George Arhonditsis  Daniela Balin  Tesfaye Kebede  Valentina Krysanova  Ann van Griensven  Sjoerd E. A. T. M. van der Zee 《水文研究》2010,24(24):3447-3461

  相似文献   

Environmental heterogeneity affects input, storage, and transformation of coarse particulate organic matter in a floodplain mosaic     

Simone Daniela Langhans  Urs Richard  Janine Rueegg  Urs Uehlinger  Peter Edwards  Michael Doering  Klement Tockner 《Aquatic Sciences - Research Across Boundaries》2013,75(3):335-348

Quantifying spatial and temporal dynamics of organic matter (OM) is critical both for understanding ecosystem functioning and for predicting impacts of landscape change. To determine the influence of different habitats and coarse particulate OM (CPOM) types upon floodplain OM dynamics, we quantified aerial input, lateral surface transfer, and surface storage of CPOM over an annual cycle on the near-natural floodplain of the River Tagliamento in NE-Italy. Using these data, we modelled floodplain leaf dynamics, taking account of the spatial distribution and hydrologic connectivity of habitats, and using leaf storage as a response variable. Mean aerial CPOM input to the floodplain was similar from riparian forest and islands, but surface transfer was greater from islands, supporting the suggestion that these habitats act as “islands of fertility” along braided rivers. Leaves were the lateral conveyor of energy to more open parts of the floodplain, whereas CPOM was mainly stored as small wood in vegetated islands and riparian forest. Simulating the loss of habitat diversity (islands, ponds) decreased leaf storage on the whole floodplain, on exposed gravel and in large wood accumulations. In contrast, damming (loss of islands, ponds and floods plus floodplain overgrowth) greatly increased storage on exposed gravel. A random shuffle of habitats led to a storage increase on exposed gravel, while that in large wood accumulations and ponds declined. These results disentangle some of the complexities of CPOM dynamics in floodplain ecosystems, illustrate the value of models in understanding ecosystem functioning at a landscape level, and directly inform river management practice.  相似文献   

Impact of loading displacements on SLR-derived parameters and on the consistency between GNSS and SLR results   总被引：5，自引：4，他引：1  

Krzysztof Sośnica  Daniela Thaller  Rolf Dach  Adrian Jäggi  Gerhard Beutler 《Journal of Geodesy》2013,87(8):751-769

Displacements of the Earth’s surface caused by tidal and non-tidal loading forces are relevant in high-precision space geodesy. Some of the corrections are recommended by the international scientific community to be applied at the observation level, e.g., ocean tidal loading (OTL) and atmospheric tidal loading (ATL). Non-tidal displacement corrections are in general recommended not to be applied in the products of the International Earth Rotation and Reference Systems Service, in particular atmospheric non-tidal loading (ANTL), oceanic and hydrological non-tidal corrections. We assess and compare the impact of OTL, ATL and ANTL on SLR-derived parameters by reprocessing 12 years of SLR data considering and ignoring individual corrections. We show that loading displacements have an influence not only on station long-term stability, but also on geocenter coordinates, Earth Rotation Parameters, and satellite orbits. Applying the loading corrections reduces the amplitudes of annual signals in the time series of geocenter and station coordinates. The general improvement of the SLR station 3D coordinate repeatability when applying OTL, ATL and ANTL corrections are 19.5 %, 0.2 % and 3.3 % respectively, w.r.t. the solutions without loading corrections. ANTL corrections play a crucial role in the combination of optical (SLR) and microwave (GNSS, VLBI, DORIS) space geodetic observation techniques, because of the so-called Blue-Sky effect: SLR measurements can be carried out only under cloudless sky conditions—typically during high air pressure conditions, when the Earth’s crust is deformed, whereas microwave observations are weather-independent. Thus, applying the loading corrections at the observation level improves SLR-derived products as well as the consistency with microwave-based results. We assess the Blue-Sky effect on SLR stations and the consistency improvement between GNSS and SLR solutions when ANTL corrections are included. The omission of ANTL corrections may lead to inconsistencies between SLR and GNSS solutions of up to 2.5 mm for inland stations. As a result, the estimated GNSS–SLR coordinate differences correspond better to the local ties at the co-located stations when applying ANTL corrections.  相似文献   

Midnight reversal of ionospheric plasma bubble eastward velocity to westward velocity during geomagnetically quiettime: Climatology and its model validation     

José H.A. Sobral  Vivian M. de Castilho  M.A. Abdu  Hisao Takahashi  I. Paulino  Ulisses A.C. Gasparelo  Daniela C.S. Arruda  Matheus Mascarenhas  C.J. Zamlutti  C.M. Denardini  Daiki Koga  A.F. de Medeiros  R.A. Buriti 《Journal of Atmospheric and Solar》2011,73(11-12):1520-1528

In an effort to better understand the dynamics of westward velocities of the nocturnal F-region plasma, the climatology of the westward traveling plasma bubbles – WTB – occurring during quiettime is studied here. The climatology of the WTB is analyzed here based on airglow images obtained during 14 quiet days between 2001 and 2006 at the Brazilian station São João do Cariri (Geographic 7.45°S, 36.5°W, dip ～20°S). The frequency of occurrence of the WTB maximizes in the descending phase of the solar cycle. The WTB velocities ranged between ～20 and 40 ms^?1. The frequency of occurrence had a peak value of only 3.65% at 2345 LT. The maximum occurrence of the WTB was in July–September. No WTB have been observed from November until April in all years 2001–2006. We show for the first time theoretically that the WTB dominant forcing mechanisms during geomagnetically quiet days are westward thermospheric winds.  相似文献   

Multiplatform observation of the surface circulation in the Gulf of Naples (Southern Tyrrhenian Sea)   总被引：1，自引：1，他引：0  

Marco Uttieri  Daniela Cianelli  Bruno Buongiorno Nardelli  Berardino Buonocore  Pierpaolo Falco  Simone Colella  Enrico Zambianchi 《Ocean Dynamics》2011,61(6):779-796

The Gulf of Naples (Southern Tyrrhenian Sea) is a highly urbanised area, where human activities and natural factors (e.g. river runoff, exchanges with adjacent basins) can strongly affect the water quality. In this work we show how surface transport can influence the distribution of passively drifting surface matter, and more in general if and how the circulation in the basin can promote the renovation of the surface layer. To this aim, we carried out a multiplatform analysis by putting together HF radar current fields, satellite images and modelling tools. Surface current fields and satellite images of turbidity patterns were used to initialise and run model simulations of particle transport and diffusion. Model results were then examined in relation to the corresponding satellite distributions. This integrated approach permits to investigate the concurrent effects of surface dynamics and wind forcing in determining the distribution of passive tracers over the basin of interest, identifying key mechanisms supporting or preventing the renewal of surface waters as well as possible areas of aggregation and retention.  相似文献   

Time and space dependency in impact damage evaluation of a sub-Plinian eruption at Mount Vesuvius     

Giulio Zuccaro  Daniela De Gregorio 《Natural Hazards》2013,68(3):1399-1423

The volcanic eruptions have produced death and devastation along the ages; the victims caused by the documented events are about 260,000. Today, people subjected to volcanic risk are 500 million. They live predominantly in large conurbations, such as Tokyo, Mexico City, Seattle and Naples, which are located in the proximity of volcanoes with a high probability to erupt. Further, cause of concern is the elevated growth rates of the urban populations in the developing countries, seeing that many cities are located just above the tectonic belts where are predominantly situated the World’s most explosive volcanoes. Therefore, the volcanic risk mitigation of these areas requires a careful territorial planning together with an adequate knowledge of the behaviour of constructions under the eruption effects. The problem is very complex considering that a several number of actions (such as lavas, earthquakes, ash fall, pyroclastic flows, ballistics, landslides, tsunami and lahars) with a peculiar time–space distribution are produced by an eruptive event. Moreover, for the impact evaluation of a volcanic eruption, the time–space effect acquires a great importance, differently by the case of single catastrophic event (such as tectonic earthquakes, debris flows, etc.), since the sequence of the several exceptional actions which occur during an eruptive event, that modify the resistance characteristics of the struck constructions, in consequence, the impact damage evaluation requires analyses, step by step, of the eruptive process, the damage accumulated on the buildings and the distribution of the damage on the territory. All these aspects are examined in this paper which furnishes a useful compendium relating to the impact damage assessment produced on buildings by an explosive volcanic eruption, through the time–space variability analysis. This document organically summarizes the results of about 15 years of researches conducted by the PLINIVS Study Centre (Study Centre for the Hydrogeological, Volcanic and Seismic Engineering) with reference to the volcanic risk assessment, in the framework of the scientific literature on the topic. The paper analyses the probabilistic approaches used these days to treat Hazard, Vulnerability and Exposure in risk and impact evaluation of volcanic eruptions. Reliability of the model available is discussed; open problems and future improvement of the research in progress are highlighted. In conclusion, recommendations to follow for impact estimation studies in volcanology are reported.  相似文献   

http://www.sciencedirect.com/science/article/pii/S1674987111000855     

Jozef Michalík  Daniela Reháková 《地学前缘(英文版)》2011,2(4):475-490

During the last decades, several integrated studies of Tethyan Jurassic/Cretaceous boundary sections from different countries were published with the objective to indicate problems for the selection of biological, chemical or physical markers suitable for identification of the Jurassic/Cretaceous boundary e the only system boundary within the Phanerozoic still not fixed by GSSP. Drawing the boundary between the Jurassic and Cretaceous systems is a matter of global scale discussions. The problem of proposing possible J/K boundary stratotypes results from lack of a global index fossils, global sea level drop, paleogeographic changes causing development of isolated facies areas, as well as from the effect of Late Cimmerian Orogeny. This contribution summarizes and comments data on J/K boundary interval obtained from several important Tethyan sections and shows still existing problems and discrepancies in its determination.  相似文献   

Discriminating the long distance dispersal of fine ash from sustained columns or near ground ash clouds: The example of the Pomici di Avellino eruption (Somma-Vesuvius,Italy)     

Roberto Sulpizio  Rosanna Bonasia  Pierfrancesco Dellino  Mauro A. Di Vito  Luigi La Volpe  Daniela Mele  Giovanni Zanchetta  Laura Sadori 《Journal of Volcanology and Geothermal Research》2008

Ash samples from tephra layers correlated with the Pomici di Avellino (Avellino Pumice) eruption of Somma-Vesuvius were collected in distal archives and their composition and particle morphology investigated in order to infer their behaviour of transportation and deposition. Differences in composition and particle morphologies were recognised for ash particles belonging to the magmatic Plinian and final phreatomagmatic phases of the eruption. The ash particles were dispersed in opposite directions during the two different phases of the eruption, and these directions are also different from that of coarse-grained fallout deposits. In particular, ash generated during magmatic phase and injected in the atmosphere to form a sustained column shows a prevailing SE dispersion, while ash particles generated during the final phreatomagmatic phase and carried by pyroclastic density currents show a general NW dispersion. These opposite dispersions indicate an ash dispersal influenced by both high and low atmosphere dynamics. In particular, the magmatic ash dispersal was first driven by stratospheric wind towards NE and then the falling particles encountered a variable wind field during their settling, which produced the observed preferential SE dispersal. The wind field encountered by the rising ash clouds that accompanied the pyroclastic density currents of the final phreatomagmatic phase was different with respect to that encountered by the magmatic ash, and produced a NW dispersal. These data demonstrate how ash transportation and deposition are greatly influenced by both high and low atmosphere dynamics. In particular, fine-grained particles transported in ash clouds of small-scale pyroclastic density currents may be dispersed over distances and cover areas comparable with those injected into the stratosphere by Plinian, sustained columns. This is a point not completely addressed by present day mitigation plans in case of renewal of activity at Somma-Vesuvius, and can yield important information also for other volcanoes potentially characterised by explosive activity.  相似文献