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1.
In order to assess the pollutant load attributable to crematoria, a study was undertaken on the emissions from cremators sited in urban areas. This paper reports some preliminary results from the testing program on an urban cremator emission as it stands with current cremation practices in Italy. Results concern the concentration of the following parameters at the stack: total particulate matter, metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl, V, Zn), organic micropollutants such as dioxins (PCDDs), dibenzofurans (PCDFs), polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs).  相似文献   

2.
Egyptian mural paintings, polychromatic sculptures and mummy coffins exhibit a remarkable durability, ranging over millennia. This phenomenon can be explained by the dry, non-corrosive climate of the Nile valley and/or by the knowledge and experience with which Egyptian craftsmen developed skills to conserve items and materials for eternity. Investigations concerning the timber and covering or protecting layers of mummy coffins are reported. The experimental results were obtained by means of thermal analysis and X-ray diffraction. The interpretation sheds light on the ancient techniques applied.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

3.
传统过程工业,诸如我国水泥、钢铁、耐材和电石等行业,都涉及碳酸盐高温热分解过程,其导致的CO2排放量超过了全国工业碳排放总量的50%,大量CO2排放对全球气候产生了不可逆转的影响。因此,如何减少过程工业排放的CO2并且充分利用碳酸盐热分解的余热面临着巨大挑战。为进一步降低该类过程工业的CO2排放量同时降低其热分解的能耗,通过利用地球上储量丰富的温室气体CH4,对碳酸盐进行共热耦合重整制备合成气等高附加值产品,有望成为一种环保经济的技术路线。本文总结了(光/热)碳酸盐炼制耦合甲烷干重整反应、醇类重整反应以及CO2捕获反应的最新进展,并且对碳酸盐炼制耦合甲烷干重整反应在理论计算方面的研究进展进行了介绍,进一步结合本课题组近期关于碳酸盐共热耦合甲烷重整的最新结果,我们提出了该类耦合反应的发展展望,为实现CO2的高效转化和减排增效提供了思路。  相似文献   

4.
Hygienic aspects related to burial   总被引:1,自引:0,他引:1  
Burial grounds are generally provided by local authorities in cemeteries (subject to planning consent and to compliance with any considerations for environmental health). Their design has been submitted to studies of hydrogeological characteristics of soil with regard to its ability to purify wastewater coming from corpse decomposition, its ability to avoid the infiltration of pollutants in groundwater, and its ability to skeletonize buried corpses within the given times foreseen by the law in force. Greater environmental awareness has necessitated that new and existing burial grounds are assessed to determine the environmental load which they could release to soil or any downstream component. This problem arises in countries where there is a high density of built-up areas, a custom of disposing of the dead by burial, a lack of available spaces and suitable soils to designate as burial grounds. This paper reports some results from a study carried out on ground lands of Italy in order to revise articles 82 and 83 of the Decree No 285 of 1990 in force in relation to burial grounds. Soil permeability to water and air is a parameter of critical importance in relation to purification and/or diffusion of leachates from inhumed corpses in the soil, and in relation to its influence on the time necessary to completely skeletonize a human corpse.  相似文献   

5.
The main aim of this project was to assess background levels of heavy metals in soil in the inland coastal area of Venice, Italy. The pilot study area is located near the industrial area of Porto Marghera, considered of national interest in terms of contaminated soil remediation (Environmental Ministerial Decree n. 471/1999). The Decree under consideration emphasises the importance of the assessment of background values in soil remediation. Results will show cases (As and Sn) in which background values are greater than concentration limit standards given by legislation.  相似文献   

6.
The human activities in their various aspects cause a change in the natural air quality. This change results more marked in very populated and in high industrialized areas. Some pollutants emitted are typical of a particular activity. Each source of pollution is identified by its profile in the composition of the emissions in the environment. Multivariate receptor models can be used in order to apportion pollutants to the different sources assessing the contribution of each source to the total pollution.This paper deals with the application of Absolute Principal Component Scores (APCS) receptor model to data obtained from the automatic network of air quality monitoring in the city of Bari (South Italy). The parameters monitored by automatic networks, as bihourly values, are PM10, NOx, CO, Benzene, Toluene, Xilene. The data shown in this paper concerning 1 month almost of sampling in different monitoring stations of Bari Municipality during the period of time from January 2005 to April 2006. Moreover preliminary results obtained applying the APCS model to daily PM2.5 samples collected during SITECOS PRIN project are shown. The results concerning data collected in corso Cavour (Bari) during the month of October 2005.The results obtained by APCS receptor model seem to suggest a poor contribution of the “vehicular traffic source” and a relevant contribution of the “secondary particulate source” to particulate matter concentrations.  相似文献   

7.
Fluorocarbon impact on ozone depletion is reviewed together with the efficacy of the Montreal Protocol in acting to correct the imbalance between stratospheric ozone production and destruction. The Protocol is also helping to reduce global warming: CFCs are shown to be currently the largest fluorocarbon contributors to climate change. Relative contributions to climate change from CFCs and their HFC substitutes are discussed, together with the consequences of control of minor greenhouse gases on an environmental impact which is dominated by carbon dioxide emissions. Both the potencies of the materials for environmental change and their concentrations in the atmosphere are important and are considered here.Trifluoroacetic acid, a minor product of atmospheric decomposition of some HCFCs and HFCs and of the pyrolysis of fluoropolymers, has been shown to be uniformly distributed in seawater to a depth of over 4000 m and so is natural, although the actual source has yet to be identified.The Montreal Protocol is only one example of action to reduce undesirable impact from fluorocarbons. Other, less universal, actions include abatement of fluoroform greenhouse gas emissions from HCFC manufacturing, process changes to eliminate trifluoromethylsulfur pentafluoride emissions from electrochemical fluorination and ceasing manufacture of perfluorooctanyl sulfonate compounds due to their persistence in human tissue.  相似文献   

8.
Fugitive emissions pose problems both for general air quality management as well as for the operational management of the facilities. In harbours, activities such loading, unloading and transport of dusty materials are important sources of particulate fugitive emissions. Therefore, there is a growing concern about air quality in these areas as a result of the high impact of the operations on human health and environment. The objectives of this study were to estimate the impact of harbour activities on air particulate matter (APM) levels and to compile an inventory of chemical profiles of harbour particulate fugitive emissions. This preliminary work was based on experimental campaigns carried out in a Portuguese harbour when different types of bulk materials were handled. High time resolution monitors were installed close to the unloaded area and recorded APM concentrations and meteorological variables. PM2.5 and PM2.5–10 were collected during unloading operations and a complete chemical characterization of collected samples was made by the techniques k 0-instrumental neutron activation analysis and particle induced X-ray emission. Results showed that manipulation of materials during harbour operations resulted in high emissions of particles, especially from the coarse fraction. These emissions were very affected by the granulometry and chemical composition of the handled materials and by the meteorological conditions.  相似文献   

9.
The growing concern about air quality in harbours is a result of the high impact of the operations on human health and environment. Harbour activities such loading, unloading and transport of dusty materials are important emission sources of Atmospheric particulate matter (APM). The assessment of these fugitive emissions is a difficult task because they depend on the materials, the type of operation and the meteorological scenarios. The main objectives of this work were (1) to evaluate if the techniques k0-based Instrumental neutron activation analysis (k0-INAA) and Particle induced X-ray emission (PIXE) are suitable techniques to assess fugitive emissions in harbours and (2) to estimate the impact of harbour activities on APM levels and composition. Several experimental campaigns were carried out in a Portuguese harbour, during unloading operations of fertilizer and phosphorite provided from Syria and Morocco. PM2.5 and PM2.5–10 were collected, in polycarbonate filters, by Gent samplers. The techniques k0-INAA and PIXE were applied as sensitive analytical tools to perform a complete chemical characterization of the collected samples. Results showed that manipulation of these materials during harbour operations resulted in high emissions of particles, principally from the coarse fraction. These emissions were very affected by the granulometry and nature of the handled materials. Fertilizer emissions were characterized by high concentration of Ca, P, K, Cr, Br and Zn, whereas phosphorite handling contributed principally for the increase of Ca, P and Cr levels.  相似文献   

10.
The practical utility of colloidal particles in the processing of ceramic oxide materials demands an understanding of the decomposition of precursor compounds as they transform to the oxide. In this exposition, the transformation of mixed rare earth hydroxycarbonate colloidal spheres to the oxide is studied. Three methods are described. In one the spheres are heated in a combined thermogravimetric and differential thermal analysis system up to 1100°C. Then successive reruns were made with specimens being cooled rapidly from the temperatures where intermediate or final reaction products are formed. X-ray diffraction patterns were taken and HREM studies were made of each sample thus produced. A second series of experiments was made in which the spheres were slowly heated to 500°C in the specimen chamber of a mass spectrometer. The gaseous decomposition products were monitored continuously. The third series involved observation of the decomposition of the colloidal spheres directly in the electron microscope. The electron-beam-induced decomposition to the oxide was followed at high resolution. The results of these three decomposition studies are compared and contrasted.  相似文献   

11.
No reference materials are currently available to study thermoanalytical kinetic methods, apparatus, or software. The ASTM International Committee E27 on Hazard Potential of Chemicals seeks to identify possible calorimetric reference materials for evaluating kinetic parameters, including activation energy (E), log pre-exponential factor (log Z), and reaction orders (m and n), as well as reaction enthalpy (H). Six candidate materials are examined including di-tertiary-butyl peroxide (DTBP), trityl azide, azobenzene, azobisisobutyronitrile (ABIN), cumene hydroperoxide (CHP), and phenytetrazolthiol. No single material appears to meet all needs. The merits and applicability of each candidate are discussed and recommended kinetic reference values are presented.  相似文献   

12.
The use of thermogravimetric analysis–mass spectrometry (TGMS) to study the state of preservation of archaeological bones has been investigated. As part of a collaborative multi-analytical study, bones exhumed from graves of the late Roman period in France and Italy were examined. A decrease in organic matter for the archaeological bones compared to that for new bone was confirmed, demonstrating that diagenesis of aged bones can be detected using TGMS. Different amounts of collagen were determined for bones from different graves and could, for the majority of specimens, be correlated with the visually observed preservation states.  相似文献   

13.
The oxo-degradation process of polypropylene (PP) samples containing different concentrations (4% and 10% w/w) of pro-oxidant/pro-degradant additive Envirocare™ AG1000C was investigated under accelerated test conditions. Samples were initially exposed to UV radiation for 300 h. The tendency to biodegradation in soil medium of these UV-aged samples was then indirectly assessed by an indirect method for a period of 6 months. The entire degradation process of these materials was first examined by monitoring changes in their morphological properties (melting temperature, maximum lamellar thickness and crystallinity) with the ageing time, by Differential Scanning Calorimetry (DSC). Then, changes in the thermal properties (onset temperature and maximum decomposition temperature) of these materials with the ageing time were analysed by Thermogravimetric Analysis (TGA). Furthermore, the kinetics of the thermal decomposition of these PP samples with pro-oxidant/pro-degradant was also studied during the oxo-degradation process, by means of the Chang differential method. During exposure to UV radiation, the more significant changes in the morphological and thermal properties that were detected in PP samples containing pro-oxidant/pro-degradant additive compared to pure PP, clearly suggest a higher level of oxidation in these samples, confirming the effectiveness of this pro-oxidant/pro-degradant additive in promoting the abiotic oxidation of polypropylene during UV-irradiation. Moreover, the level of oxidation observed in UV-aged samples seems to be dependent on the additive load.  相似文献   

14.
Light possesses momentum, and hence, force is exerted on materials if they absorb and/or scatter light. Laser techniques that use optical forces are currently attracting considerable attention. Optical manipulation for trapping, transporting small particles, and measuring the interparticle force is a representative technique. In addition, photoinduced force microscopy is a promising scanning type of microscopy using optical force. Optical force techniques have recently been used in various fields of research, such as molecular bioscience, organic photochemistry, materials engineering, and molecular fluid dynamics. In these techniques, several types of optical forces such as scattering, absorption, and gradient forces play their respective roles. In this article, we summarize the basics of optical forces and present their elementary expressions for using simplified models of light and matter systems. This will help the readers of this Special Issue to understand how different types of forces are distinguished in the basic expressions used for analyzing the optical force phenomena that appear depending on the light geometry and matter systems. After observing simplified cases of scattering and absorption forces, we introduce general formulae for the optical force and then discuss how different components appear in particular cases of laser geometry and materials.  相似文献   

15.
Monolithic materials have been widely used for over 20 years as catalyst supports in the abatement of emissions from mobile and stationary sources. They have been most successfully used for applications where high volumetric flow rates and potential for thermal shock are required. Their use is expected to further increase as new applications are found. This paper describes three new catalytic technologies which require a monolithic support; 1) the diesel oxidation catalyst commercialized in 1994 and 2) NOx abatement with hydrocarbons in lean environments and 3) catalytically supported thermal combustion both of which are currently under development.  相似文献   

16.
In the present study three thermoanalytical methods: differential thermal analysis (DTA), thermogravimetric analysis (TGA), and derivative thermogravimetric analysis (DTG) were used to investigate the thermal behavior of medicinal plant raw materials. In order to describe DTA curve, designation of the onset T(i), and peak T(p), temperatures was required. In TGA the mass losses Delta(m), and in DTG the temperature range of peak DeltaT, peak temperature T(p), and peak height h, were recorded. All parameters were read for three stages of the thermal decomposition of plant samples which resulted in obtaining eighteen thermal variables for each sample. Some similarities in the course of thermal decomposition of the same plant organs were recognized, but complexity of the obtained data made it very difficult to determine if they could differentiate between medicinal plant materials and which of them encode the most valuable information about the studied herbals. In order to confirm the existence of any relations between the chemical composition of medicinal plants and their thermal decomposition and to find out which thermoanalytical variables or decomposition stages can be considered as the most significant in terms of their evaluation, it was decided to apply fully connected feed-forward artificial neural networks (ANN). Two different training algorithms were used to address the problem: back-propagation of error and conjugate gradient descent. To verify the results two-dimensional (2-D) Kohonen self-organizing feature maps (SOFMs) were employed. Two alternative datasets of thirteen key variables discriminating plant samples have been proposed.  相似文献   

17.
Three dixanthones ( 1 – 3 ) and an unprecedented C3h‐symmetric trixanthone ( 4 ) were synthesized through a three‐step approach in overall yields above 63 %. These compounds possessed a planar π‐conjugated system and formed tight face‐to‐face columnar stacks, as confirmed by single‐crystal structural analysis. In comparison with xanthone, the fluorescence emissions of compounds 1 – 4 showed significant red‐shifts, with improved quantum yields. Moreover, the fluorescence emissions of compounds 1 – 4 could be modulated in a strongly acidic environment without decomposition, which led to a further red‐shift of the emissions, as well as enhancement of the emission intensities. These compounds have potential applications as optoelectronic materials and/or chemosensors.  相似文献   

18.
Conclusions Dioxin sampling is a complicated operation which needs to be carried out carefully with suitable specified equipment in a correct manner.The intra-laboratory precision can be within 10%. However the interlaboratory precision is very poor.There is an urgent need for certified analytical standards and reference materials to be made available for dioxin analysis at both high and low levels.Samplers without flexible links should be used whereever possible. No new sampling positions on plant with dioxin emission limits should be designed which require the use of flexible links.Regular dioxin measurement is a significant cost on small businesses where absoulte annual emissions are low but the concentrations may be above 0.1 ng TEO m–3.  相似文献   

19.
ABSTRACT

Water contamination by toxic metals through the discharge of industrial wastewater is a worldwide environmental problem. Heavy metals are currently regarded as important pollutants, becoming a severe public health problem. The adsorption from aqueous solutions of trace metals using metal-organic framework, graphene oxide, or partially reduced graphene oxide was characterized by batch measurements. The choice of these materials was made based on their high surface areas, controlled porosities, and the ability to vary the surface hydrophilicity. These materials were prepared by modified standard protocols to meet project requirements. The adsorption potential of these materials was characterized for several metals.  相似文献   

20.
Lithium‐ion batteries (LIBs) represent the state‐of‐the‐art technology in rechargeable energy‐storage devices and they currently occupy the prime position in the marketplace for powering an increasingly diverse range of applications. However, the fast development of these applications has led to increasing demands being placed on advanced LIBs in terms of higher energy/power densities and longer life cycles. For LIBs to meet these requirements, researchers have focused on active electrode materials, owing to their crucial roles in the electrochemical performance of batteries. For anode materials, compounds based on Group IVA (Si, Ge, and Sn) elements represent one of the directions in the development of high‐capacity anodes. Although these compounds have many significant advantages when used as anode materials for LIBs, there are still some critical problems to be solved before they can meet the high requirements for practical applications. In this Focus Review, we summarize a series of rational designs for Group IVA‐based anode materials, in terms of their chemical compositions and structures, that could address these problems, that is, huge volume variations during cycling, unstable surfaces/interfaces, and invalidation of transport pathways for electrons upon cycling. These designs should at least include one of the following structural benefits: 1) Contain a sufficient number of voids to accommodate the volume variations during cycling; 2) adopt a “plum‐pudding”‐like structure to limit the volume variations during cycling; 3) facilitate an efficient and permanent transport pathway for electrons and lithium ions; or 4) show stable surfaces/interfaces to stabilize the in situ formed SEI layers.  相似文献   

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