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21.
The European Operational Smog (EUROS) integrated air quality modelling system has been extended to model fine particulate matter (PM). From an extended literature study, the Caltech Atmospheric Chemistry Mechanism and the Model of Aerosol Dynamics, Reaction, Ionisation and Dissolution were selected and recently coupled to EUROS. Currently, modelling of mass and chemical composition of aerosols in two size fractions (PM2.5 and PM10–2.5) is possible. The chemical composition is expressed in terms of seven components: ammonium, nitrate, sulphate, elementary carbon, primary inorganic compounds, primary organic compounds and secondary organic compounds. Calculated PM10 concentrations and chemical composition are presented for two summer months of the year 2003 (1 July to 31 August).  相似文献   
22.
Recognition and understanding of landscape dynamics as a historical legacy of disturbances are necessary for sustainable management of forest ecosystems. This study analyzes spatial and temporal changes in land use and forest cover patterns in a typical mountain forest area in Rize Forest Enterprise of the Northeastern part of Turkey. The area is investigated by evaluated the temporal changes of spatial structure of forest conditions through spatial analysis of forest cover type maps from 1984 and 2007 using GIS and FRAGSTATS. The quantative evidences presented here showed that there were drastic changes in the temporal and spatial dynamics of land use/forest cover. As an overall change between 1984 and 2007, there was a net decrease of 2.30% in total forested areas. On one hand, productive forest areas decreased 12,506 ha, on the other hand, degraded forest areas increased 14,805 ha. In examining the changes of crown closure and development stages of forest ecosystem during the study period, the forest stand area with medium crown closures increased. Regenerated area increased while the other development stages were left to grow to mature development stages in the period. These results regarding to crown closure and development stage showed that forest quality has increased but total forest areas decreased. This is partially due to out-migration of rural population in Rize and Cayeli towns. In terms of spatial configuration, analysis of the metrics revealed that landscape structure in Study area had changed substantially over the 23-year study period, resulting in fragmentation of the landscape as indicated by the large patch numbers and the smaller mean patch sizes due to heavy timber subtraction, illegal cutting, and uncontrolled stand treatments.  相似文献   
23.
Following restoration changes in Antoninek Reservoir physico-chemical and biological processes in the water column and bottom sediments were measured to outline mechanisms of changes in nitrogen, phosphorus and organic matter concentrations during water flow through this reservoir. Intensive mineralisation of organic matter in the shallow sediments stimulated primary production and influenced increasing ammonia and nitrite nitrogen concentrations. Two main factors affected concentrations of phosphorus: (1) its presence in the external loads of river waters entering the reservoir, more important in the colder seasons as the water discharge was higher and (2) from the internal loads coming from bottom sediments. The quality of the river water during its flow through this reservoir improved for most parameters and seasons. However, concentrations of nutrients were still high in waters flowing out from the reservoir and in some months they were higher in the outflow than in waters entering the reservoir.  相似文献   
24.
A simple method for species-selective analysis of organotin compounds (OTCs) (butyl and phenyl) in sediments was developed. The sample preparation procedure was specifically optimised for sulphur-rich sediments to eliminate interferences from elemental sulphur and organosulphur compounds. Tin species were extracted from sediment samples using pressurised liquid extraction technique (PLE), ethylated - with simultaneous extraction to isooctane - in aqueous phase with sodium tetraethylborate (NaBEt(4)) and separated/detected by gas chromatography with flame photometric detection (GC-FPD). PLE operational variables (extraction temperature and pressure, solvent composition and number of static extraction steps) and extract handling routine were fine-tuned to minimise the amount of extracted interferents while keeping OTCs recovery at an acceptable level. Best results were obtained after extraction of sediment samples with methanol/water (75% v/v methanol) solution of acetic acid/sodium acetate with tropolone addition (0.6 g l(-1)). Derivatisation of low temperature, high-pressure (50 degrees C, 13.8 MPa) extracts gives isooctane extracts which are clean enough to be directly analysed by GC-FPD without any further cleanup. Interferences from elemental sulphur were completely eliminated while concentrations of other interferents were reduced to the level not impairing quantitation of OTCs under the study. No negative effects in terms of chromatographic column deterioration were observed after repeated injections of such extracts. Two certified reference materials, BCR646 and PACS-2, were analysed to assess performance of the method. Recoveries of all OTCs under the study, except MBT, were in the range of 91-114%. MBT extraction efficiency was low (34-47%) therefore the method is unsuitable for precise determinations of this compound.  相似文献   
25.
Cyclic voltammetry and spectral FTIR studies of the influence of activated carbon surface modification on the co-adsorption of metal cation (lead or iron) and phenol from aqueous acidic solution were carried out. The diversity in surface chemical structure was achieved by applying different procedures of inorganic matter removal and by modifying the carbon samples in various ways: heating under vacuum, aminoxidation in an ammonia-oxygen atmosphere, oxidation with concentrated nitric acid. The quantities of adsorbed metal ions (Pb(2+) or Fe(3+)) and phenol from solutions containing cation or phenol separately or in a mixture were determined. The adsorption capacity from acidic aqueous acidic solution depends on the chemical properties of the activated carbon surface (e.g., decrease in phenol adsorption with relative lower basicity of the adsorbent). The electrochemical parameters of electrodes made from the carbon samples were estimated, and some possible electrochemical reactions were determined from voltammograms recorded in acid electrolyte solution containing adsorbed species (separately or as a mixture). Relationships were found between metal ion adsorption and electrochemical behavior of Pb(2+)/Pb(4+) and Fe(3+)/Fe(2+) couples on the one hand, and the presence of phenol in the solutions tested and the influence of surface chemistry of the carbon electrodes on electrochemical processes on the other. The changes in adsorption capacity with respect to the adsorbates used and the changes in FTIR spectra of the carbons as a result of adsorption and/or coupling phenol molecules are discussed.  相似文献   
26.
NMR study of the humification process during sewage sludge treatment   总被引:1,自引:0,他引:1  
Humic acids, extracted from sludge at the biologic-mechanical sewage treatment plant in Jastrzebie Zdroj, have been investigated by means of (1)H, (13)C and (31)P NMR spectroscopy. Sludge samples for studies were taken from the primary settling tank, the nitrification chamber, the digestion chamber and the sludge drying beds. The (1)H NMR analysis of humic acid extracted from sludge at various stages of sewage treatment confirmed the presence of the functional groups that are characteristic for humic substances, and the analysis showed changes in their relative intensities. The (13)C NMR indicated that the aromatisation of the humic acid increased during sewage treatment. Moreover, the analysis of the (31)P NMR spectra allowed us to observe the changes in the phosphorus groups of the studied humic acids.  相似文献   
27.
Co-combustion of dried sewage sludge and coal in a pulverized coal boiler   总被引:1,自引:0,他引:1  
More than 1.1 million tons of municipal and industrial sewage sludge is produced annually in Poland. Most of this sewage sludge is landfilled or used for recultivation and fertilization of soil. After accession of Poland to the EU, large investments are planned for wastewater treatment, so it is expected that the amount of sewage sludge produced in Poland will grow in the near future. It is well known that the combustion of sewage sludge is becoming a more and more popular utilization method of such waste. Unfortunately, the current situation in Poland makes it impossible to incinerate the sewage sludge because of a lack of incinerators. One possible solution for Poland is the co-firing of dried sewage sludge in existing coal-fired utility boilers. This article presents results of initial Polish industrial trials of dried municipal sewage sludge and hard coal co-combustion in an OP-230 pulverized coal boiler. Such a solution was shown to be technically viable and not to require changes to the existing technological system. Cocombustion of sewage sludge with coal in power plants seems to be the best solution for sludge utilization in the near future in Poland.  相似文献   
28.
Inorganic aluminum ions, [Al(H2O)6]3+, [Al(OH)(H2O)5]2+, and [Al(OH)2(H2O)4]+, are toxic to a number of crops. The aim of this study was to estimate the danger of soil contamination of bioavailable aluminum and heavy metals forms because of alum sludge which was a by-product of water, and wastewater treatment technology using aluminum coagulant is introduced into the soil. Aluminum and selected heavy metal fractionation was carried out in the post-coagulation sludge collected at a water treatment plant (where aluminum was used as a coagulant), fermented sewage sludge at a municipal wastewater treatment plant (which did not apply aluminum coagulant), and soil from water treatment plant as well as the mixtures of sludge and soil. It has been found that post-coagulation sludge used as natural fertilizer is a secondary source of bioavailable aluminum, especially when aluminum coagulants are used during water and wastewater treatment. The evaluation of applicability of the sludge to very weak acidic and acidic agricultural soils was carried out. The authors shall debate the question whether, in this case, the Regulation of EU and Polish Government on sewage sludge should also take the bioavailable aluminum into account and add to the list of the elements whose allowable contents are limited.  相似文献   
29.
The paper presents two aspects concerned with the mercury air emission inventory from coal-fired public power and energy plants: an uncertainty analysis, using Monte Carlo simulation (Journal of the American Statistical Association, 44(247), 335–341 1949) and the monthly distributions applying the Denton-Cholette approach (Dagum & Cholette 2006). The analysis determines uncertainty about the estimates mercury air emission from 1990 to 2012 including the development of air pollution control (APC) technologies in the Polish public power and energy sector, also the monthly distributions in comparison with previously obtained results (H?awiczka 2008). The uncertainty of mercury (Hg) content in fuel is 31.6% for hard coal and 42.4% for brown coal. The confidence interval for the estimated emission changed from [kg] (16,082.2; 16,242.2) in 1990 to (10,525.9;10,671.1) in 2012. However, the Denton-Cholette approach overestimates the emissions for the warmer periods of the year, but it could, however, in our view, be applied to attain the monthly distributions.  相似文献   
30.
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