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341.
The aim of this work is to investigate the application of fly ash adsorbent for removal of arsenite ions from dilute solution (100–1,000 ppm). Experiments were carried out using material from the “Turów” (Poland) brown-coal-burning power plant, which was wetted, then mixed and tumbled in a granulator to form spherical agglomerates. Measurements of arsenic adsorption from aqueous solution were carried out at room temperature and natural pH of fly ash agglomerates, in either a shaken flask or circulating column, to compare two different methods of contacting solution with adsorbent. Adsorption isotherms of arsenic were determined for agglomerated material using the Freundlich equation. Kinetic studies indicated that sorption follows a pseudo-second-order model. Preferable method to carry out the process is continuous circulation of arsenite solution through a column.  相似文献   
342.

Chemiluminescence appearing during oxidation of isoproterenol using chemical system involving superoxide anion radical has been studied. Chemiluminescence and fluorescence spectra were measured. The chemiluminescence spectrum was measured with cut‐off filters and revealed bands with maximum at 440, 480, 550, 640 and 700 nm. The bands at 480, 640 and 700 nm were similar to those observed for singlet oxygen. The fluorescence spectrum exhibited maximum at 560 nm.

The inhibitory effect of several biologically important compounds known as O2 ?‐ HO? and 1O2 scavengers on the light emission was studied.

The obtained results indicate that oxidation of isoproterenol by O2 ?‐ involves products in the electronically excited states. The data also seem to indicate the protective effect of isoproterenol on the deoxyribose degradation.  相似文献   
343.
Cd, Zn, Cu, and metallothionein (MT) levels have been determined in the renal cortex and liver of 70 persons who died in Lodz and its surroundings in the years 1985–1989. The mean concentrations were: 44.9±28.6 µg Cd/g, 52.0±16.7 µg Zn/g, 2.4±1.0 µg Cu/g, 0.79±0.40 µmol Hg/g, and 3.5±1.8 µg Cd/g, 66.7±30.5 µg Zn/g, 4.9±2.1 µg Cu/g, 0.50±0.38 µmol Hg/g wet tissue in renal cortex and liver, respectively, with mean age 54.0±13.8. Smokers showed 2.4 times higher levels of Cd in the renal cortex than non-smokers. The mean body burden of Cd was 33.4±17.3 mg. Smoking increases it twofold from 22.0 mg in non-smokers to 41.8 mg in smokers.This work was supported by the grant CPBR 11.12(C-56/86) from the Institute of Rural Medicine, Lublin, Poland.Deceased.  相似文献   
344.
ABSTRACT

Pharmaceutical compounds are considered emerging environmental pollutants that have a potential harmful impact on environment and human health. In this study, the spiky green horse-chestnut shell was used for the biosorption and removal of acetaminophen from aqueous solution. It was analysed how the parameters, like contact time, pH, mass of biosorbent and temperature, influence the effectiveness of acetaminophen removal from aqueous solutions. The equilibrium was quickly achieved after 10?min (~60%). The amount of acetaminophen adsorption slightly increased with the increase of the mass of biosorbent, and for example for an aqueous solution containing 10?mg/L of acetaminophen adsorption was increased from 62% to 81%. The promising results obtained at pH ranged between 2 and 9, which shows that the adsorption of acetaminophen did not depend on the pH and it may be a consequence of the predominant microporous sorbent and its surface charge. The result is better correlated to a pseudo-second-order kinetic model of type 2 (r 2?=?0.9992) than pseudo-first-order. A sorption mechanism of acetaminophen on biosorbent was also proposed. The sorption of acetaminophen over biosorbent is mainly preceded by hydrophilic interactions between hydroxyl and carbonyl groups in pharmaceutical molecules and hydroxyl and carboxyl groups on the surface of biosorbent.  相似文献   
345.
With the present development of digital registration and methods for processing speech it is possible to make effective objective acoustic diagnostics for medical purposes. These methods are useful as all pathologies and diseases of the human vocal tract influence the quality of a patient’s speech signal. Diagnostics of the voice organ can be defined as an unambiguous recognition of the current condition of a specific voice source. Such recognition is based on an evaluation of essential acoustic parameters of the speech signal. This requires creating a vibroacoustic model of selected deformations of Polish speech in relation to specific human larynx diseases. An analysis of speech and parameter mapping in 29-dimensional space is reviewed in this study. Speech parameters were extracted in time, frequency and cepstral (quefrency) domains resulting in diagrams that qualified symptoms and conditions of selected human larynx diseases. The paper presents graphically selected human larynx diseases.  相似文献   
346.
Improvement of occupational safety and health (OSH) management is closely related to the development of OSH performance measurement, which should include OSH outcomes (e.g., occupational accidents), OSH inputs (including working conditions) and OSH-related activities. The indicators used to measure the OSH outcomes are often called lagging indicators, and the indicators of inputs and OSH activities are leading indicators. A study was conducted in 60 companies in order to determine what kinds of indicators were used for OSH performance measurement by companies with different levels of OSH performance. The results reveal that the indicators most commonly used in all of the companies are those related to ensuring compliance with the statutory requirements. At the same time, the leading indicators are much more often adopted in companies with a higher performance level. These companies also much more often monitor on a regular basis the indicators adopted for the evaluation of their OSH performance.  相似文献   
347.
This paper provides quantitative information on the transfer of TBT (tributyltin) and TPhT (triphenyltin) from sludged soil to cultivated lettuce. The effect of their initial concentrations in the soil (varying from 20 to 50 microg(Sn)kg(-1) for each triorganotin), sludge amount (between 1% and 9%), and cultivation duration (32-54 days) was evaluated by means of experimental designs. The impact of the cultivation temperature at 13 degrees C and 19 degrees C on organotin fate in the soil/plant system was also considered. The final concentration of a given organotin in the plant roots was found to depend directly on its initial concentration in the soil. A total of (85+/-15)% of initial TBT in the soil was still present at the end of the experiments, regardless of the cultivation duration. Consequently, TBT appeared to be taken up by lettuce continually. A total of (75+/-5)% of TPhT was found to be degraded in the soil at 54 days. So, this compound could have been taken up by the plant at the beginning of the cultivation. Sludge amount seemed to have a negative effect on TPhT concentration in a plant at 32 days. This could be due to the quantitative TPhT sorption onto the sludge, observed just after spiking. Organotin plant uptake appeared to be more important at 19 degrees C than at 13 degrees C. TBT and TPhT were mainly accumulated in the roots, and up to 2% and 10% of TPhT and TBT, respectively, were translocated to the shoots. Despite TPhT degradation, products in large amounts were present in the soil and were not significantly taken up by the plant. They possibly remained immobilized on solid phases of the sludged soil.  相似文献   
348.
This paper reports results of gamma and alpha spectrometric measurements for mosses, lichens, fungi and soil samples from areas in the Balkans targeted by depleted uranium (DU). Samples were collected in 2002 and 2003 in the vicinity of several villages, principally Han Pijesak (Bosnia and Herzegovina, hit by DU in 1995) and Bratoselce (South Serbia, hit by DU in 1999) and in lesser numbers from Gornja Stubla, Kosovo (which is identified as a high natural radon/thoron area) and Presevo close to the Kosovo border. In the course of gamma spectrometric measurements some results suggested samples with unusual high uranium contents which might be considered to be a signature for the presence of DU, although many samples had very high detection limits. Alpha spectrometric measurements directly proved the presence of DU for five samples, all from directly targeted places. These were samples of mosses, lichens and soil. For some samples homogeneity tests were applied which showed a rather even distribution of DU in these samples. No trace of DU was found in any sample from a dwelling.  相似文献   
349.
In this study, seasonal observations of radon concentration changes inside buildings carried out in the northeastern region of Poland is presented. One-year measurements of radon concentrations were performed in chosen buildings. The integral method of Cr-39 trace detectors in diffusive chambers was used. Mean values of radon concentrations were determined in monthly, 2-, 3-, 6-month, and annual observations. The fraction of a mean annual concentration of the value obtained in a shorter observation was calculated. Monthly concentration values were from about 0.2 to 14.9 of the annual mean. All buildings revealed seasonal fluctuation of radon concentration. Negative correlation of indoor radon concentration in the buildings and the mean temperature outside was observed in most examined buildings. The lowest coefficient range, determining which part of the annual mean value would be obtained in the 6-month observation, was gained for exposure begun in April or October.  相似文献   
350.
Urban air particulate matter (APM) was collected at two sampling sites in the city of Lodz, Poland in March, May and July 2001. The concentrations of several trace elements (TEs) as well as heavy metals were determined by neutron activation analysis (NAA). It was found that for many elements, the contribution of the blank values arising from the filtering material is very high, especially for glass fiber filters. The results obtained for Lodz were compared to those obtained for Milan, Italy. The data of Lodz are, in general, lower than those found in Milan downtown in the winter season. The influence of three coal-fired power plants located within the city of Lodz on the concentration of trace elements in APM was also considered.  相似文献   
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