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Number of results: 9
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Abstract

Sand samples with furan binder were prepared using Sand, Furfuryl Alcohol and Toluene Sulfonic Acid with ratio 100:0.85:0.30. To identify and quantify gases releasing from furan binder various studies like FTIR, TGA and GC-MS were carried out. After analyzing our materials using above mentioned characterizations the chemical formula of the Resin and Binder and amount of gases releasing from composition were confirmed. After studying various reports on pyrolysis process of furan binder calculation of the % of various gases emitting during pyrolysis process of furan was carried out. Sample of gas collected from mold was analyzed using GC-MS. Based on GCMS measurement various gases emitting from furan sand mold were identified and their amount were calculate and compared with the international standers of permissible gas emission limits in a foundry. The purpose of this paper is to assist foundries in pollution prevention by devising clean technologies which maintain or improve the quality of ambient surrounding. This paper aimed at minimization of pollution of air by using various techniques.
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Abstract

The work presents examination results of the common determination of PAHs and PCBs in industrial sludge and supernatants. Sewage sludge was taken from the wastewater treatment plant, and supernatants were obtained by their centrifuging. The prepared samples of sewage sludge and supernatants were subjected to extraction with applying the mixture of organic solvents. Cyclohexane and dichloromethane were used for constant samples, and methanol, cyclohexane and dichloromethane - for liquid. Extracts, after separation from samples of sewage sludge and supernatants, were cleared on the silica gel in vacuum conditions and concentrated in the stream of nitrogen. In such prepared extracts there was conducted the qualitative-quantitative analysis of 16 PAHs using the GC-MS system. Next, the samples were evaporated and poured with water and methanol until the clear solution was obtained. Extracts were cleared on octadecyl C18 columns, and then concentrated in the nitrogen stream. In these extracts PCBs was also determined with the application of the gas chromatograph with mass spectrometer. The range of concentrations 16 PAHs in sewage sludge equalled 10-16 mg/kgd.w. Summary average concentration 16 PAHs in supernatants was reached 17 μg/L. Average recovery of PAHs introduced to sewage sludge in the form of reference mixture was 78% (with consideration of naphthalene). In the case of supernatants, the average value of recovery reached 60%. Average PCBs concentration in supernatants equalled 10 ng/L. For sewage sludge the sum of marked PCBs was an average 1.23 μg/kgd.w.. In the case of particular PCBs the percentage recovery of the reference mixture for supernatants was 86%, while for sewage sludge it was 55%.
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Abstract

The paper presents the results of thermoanalytical studies by TG/DTG/DTA, FTIR and GC/MS for the oil sand used in art and precision foundry. On the basis of course of DTG and DTA curves the characteristic temperature points for thermal effects accompanying the thermal decomposition reactions were determined. This results were linked with structural changes occurred in sample. It has been shown that the highest weight loss of the sample at temperatures of about 320°C is associated with destruction of C-H bonds (FTIR). In addition, a large volume of gases and high amounts of compounds from the BTEX group are generated when liquid metal interacts with oil sand. The results show, that compared to other molding sands used in foundry, this material is characterized by the highest gaseous emissions and the highest harmfulness, because benzene emissions per kilogram of oil sand are more than 7 times higher than molding sand with furan and phenolic binders and green sand with bentonite and lustrous carbon carrier.
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Abstract

Suitability of the given binding agent for the moulding sands preparation depends on the one hand on the estimation of technological properties of the sand and the mould made of it and the obtained casting quality and on the other hand on the assessment of this sand influence on the natural and working environment. Out of moulding sands used in the foundry industry, sands with organic binders deserve a special attention. These binders are based on synthetic resins, which ensure obtaining the proper technological properties and sound castings, however, they negatively influence the environment. If in the initial state these resins are not very dangerous for people and for the environment, thus under an influence of high temperatures they generate very harmful products, being the result of their thermal decomposition. Depending on the kind of the applied resin (phenol-formaldehyde, urea, furfuryl, urea–furfuryl, alkyd) under an influence of a temperature such compounds as: furfuryl alcohol, formaldehyde, phenol, BTEX group (benzene, toluene, ethylbenzene, xylene), and also polycyclic aromatic hydrocarbons (PAH) can be formed and released. The aim of the study was the development of the method, selection of analytical methods and the determination of optimal conditions of formation compounds from the BTEX group. An emission of these components constitutes one of the basic criteria of the harmfulness assessment of binders applied for moulding and core sands. Investigations were carried out in the specially designed set up for the thermal decomposition of organic substances in a temperature range: 5000 C – 13000 C at the laboratory scale. The object for testing was alkyd resin applied as a binding material for moulding sands. Within investigations the minimal amount of adsorbent necessary for the adsorption of compounds released during the decomposition of the resin sample of a mass app. 15 mg was selected. Also the minimal amount of solvent needed for the desorption of compounds adsorbed in the column with adsorbent was found. The temperature range, in which the maximal amounts of benzene, toluene, ethylobenzene and xylenes are released from the resin, was defined. The qualitative and quantitative analyses of compounds from the BTEX group were performed by means of the gas chromatography combined with the mass spectrometry (GC/MS).
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Abstract

This study investigates the acaricidal, ovicidal, and repellent effects of the Tagetes patula Linn. (Asteraceae) leaf extract against both the adult female and egg stages of Tetranychus urticae Koch (Trombidiformes: Tetranychidae) under laboratory conditions. The Tagetes patula ethanolic leaf extract [TpEtOH70%] was screened for adulticide and ovicide bioassays in order to consider its acute toxicity. One sublethal concentration was used to assess egg-laying capacity (fecundity), repellent, and oviposition deterrent activities. The chemical characterization was conducted by gas chromatography-mass spectrometry (GC-MS) analysis to identify the TpEtOH70% bioactive components. Results showed that the LC50 value of TpEtOH70% leaf extract predicted by Probit analysis against T. urticae adult females at 24 h was 0.99%. The TpEtOH70% leaf extract showed a significant toxic effect as the highest mean mortality rates (± SE) of the treated adult females was 88.9 ± 3.7%. However, the TpEtOH70% leaf extract was insignificant in affecting the egg-laying capacity of the adult females treated with a sublethal dose of 0.5% even after 72 h. The TpEtOH70% leaf extract was classified repellent since the repellent index (RI) value was lower than 1 – SD. In addition, it had a high oviposition deterring effect based on a 100% reduction of the total number of eggs. The TpEtOH70% leaf extract had a significant ovicidal effect on T. urticae eggs, with 56.04% reduction in hatching. Five bioactive compounds from various classes of phytochemicals were identified in the TpEtOH70% leaf extract and the major compound was phytol (62.72%). This pioneering investigation reveals the adulticidal, ovicidal, and repellent activities of the TpEtOH70% leaf extract against T. urticae. A combination of multiple modes of action of different plant components may act alone or in synergism to delay the development of mite resistance.
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Abstract

Five cosmetics wastewater samples were treated by Dissolved Air Flotation (DAF) assisted by coagulation. Different aluminum based coagulants were used: (Al2(SO4)3, Al 1019, Al 3010, Al 3030, Al 3035, PAX 16 and PAX 19). The raw wastewater COD values were in the range 285-2124 mg/l. The efficiency of DAF depended on different coagulants and production profi le of factory. COD removal was varied from 11.1 to 77.7%. The efficiency of coagulants was similar during treatment of particular sample. The best results were obtained with Al2(SO4)3 and for sample 5 - lotions and shampoos production. The wastewater from UV fi lter creams production (sample 4) was resistant to treatment by DAF regardless of used coagulant. HS-SPME-GC-MS analysis can be a confirmation of DAF effectiveness
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Abstract

This paper aims at presenting the possibilities of applying gas chromatography for the determination of pharmaceutical residues in different matrices. Section one of the study underscores the environmental advantages of employing GC for such analyses. Section two presents the innovative methods for determining pharmaceuticals in the environment. The last section discusses the results of the analysis of the GC and GC-MS market in Poland. According to the literature data, the described methods were applied for the analysis of real samples: wastewaters, surface waters, soil samples. The samples were collected from the Pomerania region and the Gulf of Gdańsk. The pharmaceuticals were determined in various environmental samples. The highest concentrations were found in raw wastewater, medium – in a treated wastewater, and the lowest – in surface water. The most frequently detected pharmaceuticals were: ibuprofen, paracetamol, diclofenac and naproxen, all belonging to NSAIDs. Furthermore, the results of the study of the Polish GC market indicate that a very limited number of entities are currently using chromatographic techniques, and pharmaceutical residues tests are exceptions, mainly due to the lack of the legal requirements in this field and the lack of own laboratories.
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Abstract

The furan resin offers advantages such as high intensity, low viscosity, good humidity resistance and is suitable for cast different casting alloys: steel, cast iron and non-ferrous metal casting. For hardening furan resins are used different hardeners (acid catalysts). The acid catalysts have significant effects on the properties of the cured binder (e,g. binding strength and thermal stability) [1 - 3]. Investigations of the gases emission in the test foundry plant were performed according to the original method developed in the Faculty of Foundry Engineering, AGH UST. The analysis is carried out by the gas chromatography method with the application of the flame-ionising detector (FID) (TRACE GC Ultra THERMO SCIENTIFIC).
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Abstract

The results of investigations of three commercial binders applied in the Alphaset technology marked as: Sample E , Sample T and Sample S are presented in the hereby paper. These samples were subjected to the pyrolysis process at a temperature of 900°C (inert atmosphere, He 99.9999). The gas chromatograph coupled with the mass spectrometer and pyrolizer (Py-GC/MS) were used in the study. The identification of gases emitted during the thermal decomposition was performed on the basis of the mass spectral library. The obtained results indicate a certain diversification of emitted gases. Among the pyrolysis products the following harmful substances were identified: furfuryl alcohol, formaldehyde, phenol and also substances from the BTEX (benzene, toluene and ethylobezneze and xylenes) PAHs (Polycyclic Aromatic Hydrocarbons) and VOC groups (Volatile Organic Compounds). Therefore, from the environment protection point of view performing systematic investigations concerning the harmfulness of binders applied in the moulding and core sands technology, is essential.
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