Investigation of Environmental Pollution by Molecular Aabsorption Spectroscopy

Transcription

1 Investigation of Environmental Pollution by Molecular Aabsorption Spectroscopy Neset. Izairi 1, Muhamet Shehabi 2, Fadil Ajredini 1, Lutfi Istrefi 3 1 Department of Physics, Faculty of Natural Sciences and Mathematics, State University of Tetova, Tetovo, Republic of Macedonia 2 Department of Chemistry, Faculty of Natural Sciences and Mathematics, State University of Tetova, Tetovo, Republic of Macedonia 3 Department of Physics, Dept. of Physics,University in Prishtina, R. of Kosova; Dept. of Physics, Faculty of Natural Sciences and Mathematics, State University of Tetova, Tetovo, Republic of Macedonia Abstract This paper contain the molecular absorption spectroscopic investigation on environmental pollution by many pollutants. For this purpose a laser absorption spectroscopy at 630 nm wavelength have been applied to excited the molecular spectra in order to identify the presence of main gas pollutants. The following vas the experimental procedure. Preliminary the presence of pollutants was identified. The gas champions were taken in leave environ, in the Tetova streets where cars moved, and in some points in Tetova suburb, during different period of the day. A special civet, part of the apparatus, has been filled by environmental air, and latter, putted into the apparatus. A laser beam pulls pas throughout absorbing gas medium inter the civet to excite the gas, and the absorbing spectra were automatically registered. The molecular band spectra registration has been performed by an FT-IR Spectrometer (Spectrum BX FT-IR, Perkin Elmer). For this purpose the measurements were focused in spectral region of 2075 cm -1 to 2384 cm -1 for CO 2 and CO bands investigation. The importance of such measurements are to investigate the spectral properties of absorption spectra and molecular structure, and for monitoring the environmental pollution.. Key words: absorption, molecular spectra, pollution, monitoring. Introduction The problem of environmental pollution exist in global dimension, and unfotunetly became more and more sharp every year, in general and CO 2 polution in particular. The folowing example may ilustrate this problem: according a report of IPCC (Intergovernmental Panel on Climate Change), for covering the energetic needs of people, last 100 years in industrial processes nearly 400 billions ton of CO 2 vere emited in Earth atmosfere. Physics and some other sciences have established many methods and techniques to investigate this problem, in order to solve this,very important, leaveing problem Different branches of industry, leave amounts of different nonproducting materials, whic very ofen gone to burning processes. The after burning products, usualy CO 2, CO, SO 2 and other gases emited in atmosfere. After indystry, the next very important polutant of the environmental and the atmosferic air is emission of gases by cars in every day trafic. In some official documents of autorities [21] is indicated that the must polluted in Macedonia are Skopje, Tetova, Bitola and Veles. In this document [21]. they say that the limit of pollution is for time biger than the allowed on. The pollution in Tetova came from all factors mentioned above: from industry objects, trafic cars especialy these more 10 year olds, smog emited through dvellin heating of wood and lignit, and diessel oil burning. We concludet experimentaly that the pollution percentage is higher during the vinter seasone, vhen about 40 % come from lignit and 30 % from wood materials burned for home heating of populations. The old industry object in Tetova are Jugohrom, Teteks, some bilding material producers in town suburb, some producers of chemical materials for bilding and so on. BALWOIS Ohrid, Republic of Macedonia - 25, 29 May

2 We cannot estimate what is the impact of such pollution against humans, animals and plants. This belong to medical and other field experts to say these word. But, in global dimensions institutions have alarmed for harming impact of CO 2 and other above mentioned pollutants. In order to determination the pollution problem in Tetova and in Tetova suburb, we chuse some points inside Tetova to measure the pollution by cars gas emission and others pollution sources, and some points aut of Tetova in region Sunny Hill. The resoults of the experiments are good contribution to investigation the pollutions in the region and for the scientific field of the application the metode of absorption molecular spectroscopy for monitoring the problem of environmental pollution. Method and experiment Different spectroscopic methods are used for fundamental and applicational investigation of proceses conected with atomic and molecular emmision and absorption. The method offer data to investigate the structure and properties of atoms and molecules in different media. The molecular absorption spectroscopie method based on absorbic interaction of electromagnetic radiation with mater has been used to study absorbic spectra of CO, CO 2 and some other molecules in environmental and atmosferic gases. The experimental arangement is presented in fig. 1. The molecular band spectra registration has been performed by an FT-IR Spectrometer (Spectrum BX FT-IR, Perkin Elmer). For this purpose the measurements were focused in spectral region of 2075 cm -1 to 2384 cm -1 for CO 2 and CO bands investigation. The gas champions were taken in leave environ, in the Tetova streets where cars moved, and in some points in Tetova suburb, during different period of the day and season. A special civet, part of the apparatus, has been filled by environmental air, and latter, putted into the apparatus. The gas from environment was taken directly throughout a latex baloon, and later, the instruments kivet was fillet with gas from the baloon. A laser beam wavelength λ=633 nm (wave number betwen 4000 cm -1 to 400 cm -1 ) puls pas throughout absorbing gas medium inter the civet to excite the gas, and the absorbtions spectra were automatically registered. The advantage of the laser molecular spectroscopy absorbic method, against the clasical method, consist in the fact that we can have very fast experimental information and complete resoults. The method is possible to use even the experimental campion is very small, some traces or, pollutants or trace elements for analitical purposes, inorganic and organic analyses. The IR absorbic spetra vere registered directly by computer. Later by analysis of the registered spectra the absorbed frequencies of the laser beam in CO and CO 2 Different bonds type (C=O, C=N, C=C, C-C, ) molecular band vibrational spectra showed different absorption peak on lines. This make available to find the percentage of pollutants. The interpretation of IR spectra is difficult and depends on spectral resolutin parameters. In the spectral region with wave number 4000 cm -1 to 400 cm -1 is not very difficult to identify the bands frekuencies but in the spectral region about 1400 cm -1 the interpretation is the procedure is difficult. The method is possible for IR spektral analyse for solids, liquids and gas campions. The laboratory and the experiment arangement The Spectrum BX FT-IR is instaled in the Physics-Chemistry Deppartment at the Faculty of Natural Sciences in State University of Tetova. In the image. 1 is showed the Perkin Elmer Spectrum BX FT- IR spectral apparatus. In Image.2, 3, 4 and. 5 are showed some accesories of Spectrum BX FT-IR in different projections. BALWOIS Ohrid, Republic of Macedonia - 25, 29 May

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4 Results and discutions When we investigate the pollution problem in some region, we need to investigate separately lokale and regional impacts of such pollution on environment. With the term gas polutants we should understend the gases coming from a concrete source. These measurements were performed during the summer season, so we did not include in our measurements the gases from dwellin heating sources. The molecular spectra in spectral region wave number betwen 4000 cm -1 to 400 cm -1 were registered by the procedure explained above. After preliminary measurements, primary was possible to identify the CO 2, CO,, SO 2 and NO x bands which are the main polutants in streats and leawing areas. 100 spectrum of CO T, % Wavenumber, cm -1 Fig. 1 Provides IR-spectrum of carbon dioxide in the gaseous state The analysed gas campion let fall from the cars on the streat in center of Tetova. The aim wat to test the method for determining the cancetration of ommited gases as a monitoring method for pollution estimation, likewise the study of CO 2 spectral band branches. The original registered spectra is presented in Fig. 1. The CO 2 gas spectra The pure CO 2 gas spectra was registered, Fig.1, this was helpful to make possible to identify the gas pollutant traces in the registered spectra from the environment. From the figure is very easy to identify three main bands of CO 2. The asymmetric vibration (C=O) of CO 2 close to 2349 cm -1. Also, we can see the less intensive CO 2 bands vibrational band 2024 cm -1 and rotational 2290 cm -1 wave numbers, also the P,Q and R branches of the CO 2 spectra. The analytical data of gases omissioned by different type of cars Gas samples omissioned by a number of different cars and with different carburants (diesel and gasoline) vere analysed. The car produced year was different. The data are presented in the table, from the table in continuation. From the table is possible to see that the ammounts (mmol/m 3 ) is depends on type of car and how many years old is the car) BALWOIS Ohrid, Republic of Macedonia - 25, 29 May

5 Tabelary presentation of experimental data for analytical calculation for some type of cars Type of car I (%) I 0 (%) T(%) A (%) C CO2 (mmol/m 3 ) C CO (mmol/m 3 ) Renault Megan 2008 dizell 88,19 90,09 97,89 0,92 3,15 0 Toyota Carola 2008 benzin 85,189 86,59 98,37 0,713 2,42 1,723 Hundai-gertz 2004 benzin 87,163 88,74 98,22 0,78 2,65 2,5 Astra a 1998 benzin -0,811 82,53 0, , ,6 Rover 1998 diesel 0,642 83,93 0, ,8 2,576 Fiat Punto 1995 diesel 80,08 90,11 97,77 0,97 3,33 0,076 Ford ekscord diesel 2,17 83,65 2,59 158,6 539,4 1,284 The contrentration of CO 2 and CO in environement According the analysis of registered spectra of gas pollutants in some referent points in Tetova and in the Tetova suburb was possible to determine the contrentration of CO 2 and CO in environement. The results are presented in grafics Fig. 2 and Fig. 3. In the grafiks are ploted the contrations against altitude in different points from Tetova to Sany Hill. From the diagram is possible to see some discrepancy of CO 2 and CO concentration against height above the sea level. The referent poins is taken the center of Tetova town (480 m height above the sea), than villages Gajre (650 m), Lisec (1350 m), location Guri i Sidollit (1490 m), Kodra e Diellit (locaton 1, with 1650 m height above the sea), Kodra e Diellit (locaton 2, with 1707 m height above the sea). From the diagram we can see highest ammount of CO 2 in Tetova center, (9,8 mmol/m 3, we can see lowering of contrentation in Gajre and Lisec. In the next points (Guri Sidollit and Kodra e Diellit) is normally to expect smaller concentations. To contrary, the measured concentration are higher. Really, this was unexpectable, but there may consider many reasons influencing this experimental facts. The geografik faktors, relief and etc., may have some impacts against atmosfere. The air parameters may have considerable varyation depending on temperature, density and constitution of air, and, of course the humidity. It is well known the reaction of CO 2 and CO with water in which some agregates and chemical composites are created (cabronik acid and some other composites).the same regularity is present in the grafik for CO concetration, in the Fig. 3. In this case are valid the same scientifik argumentations. The carbon dioksid and the carbon monoksid are, chemikally probably, the same gas. BALWOIS Ohrid, Republic of Macedonia - 25, 29 May

6 From the two diagrams is possible to estimate the ammount of CO 2 for 99% higher than this of CO. 40 c=39.49mmol/m 3 C(mmol/m 3 ) for CO c=27.56mmol/m 3 c=16.7m m ol/m 3 c=9.86mmol/m 3 c=8.72mmol/m 3 c=8.63mmol/m Tetovë Gajre Lisec Kodra e Diellit 1 height above sea/ m) Fig.2 Kodra e Diellit 2 Guri i Sidollit 1.4 c= mmol/m m 1.2 C(mmol/m 3 ) for CO c= mmol/m m c=0.649 mmol/m m c=0.2957mmol/m 3 c= mmol/m 3 c= mmol/m m 650 m 1350 m Tetovë Gajre Lisec Kodra e Diellit 1 Kodra e Diellit 2 Height above sea (m) Guri i Sidollit Fig. 3 BALWOIS Ohrid, Republic of Macedonia - 25, 29 May

7 References [1] P.W. Atkins, Molekular Quantum Mechanics ( Part II and III), Clarendon Press, Oxford, 1970 [2] A. P. Thorne, Spectrophysics, Chapman and Hill, Nev York, A.A. [3] L. Istrefi, Metodat e Analizës Spektrale, Prishtinë, 2007 [4] G. Jashari, Fizika Atomike dhe Molekulare, Prishtinë, 1999 [5] Pretsch Clerc Seibl Simon, Tablice za određivanje strukture organski spojeva spektrskopskim metodama, S njemačkog proveli Z.Meić i M.Žinić SKTH/, Kemija u industriji, Zagreb 1982 [6] Alqi Çullaj, Kimia e Mjedisit, Tiranë, 2005 [7] Climate Change (2001b). Impacts, Adaptation and Vulnerability. Working Group II of the IPCC, Geneva, 2001.\ [8] K. Peter C. Vollhard, N. E. Score, Organic Chemistry, Structure and function, New York, Basingstoke, 2003 [9] S. H. Pine, J. B. Handricson, D. J. Cram, G. S. Hammond, Organic Chemistry [10] G. Damani, Kimia Organike, Teori dhe probleme të zgjidhura, Tiranë, 2006 [11] D.R. Bloch, Organic Chemistry demystified, Mc. Graw Hill, New York, San Francisco, London, Madrid, Sidney, Toronto [12] B. A. Hathaway, Barron s Organic Chemistry, The esay way, New York, 2006 [13] N. Daci, Kimia Organike, Prishtinë, [14] P. Atkins, Atkins Molecules, Cambridge University Press, 2006., [15] D. L. Pavia, G. M.Lampman, G. S. Kriz, R. G. Engel, Introduction to Organic Laboratory Techniques, (a small scale approach),saunders College Publishing, 1990, Fort Worth, Philadelphia, San Diego, New York, Orlando, Austin, SanAntonio, Toronto, Montreal, London, Sydney, Tokyo. [16] Ch. E. Bell, A. K. Clark, D. F. Taber, O. R. Rodig, Organic Chemistry Laboratory, Saunders College Publishing, 1998, Fort Worth, Philadelphia, San Diego, New York, Orlando, Austin, SanAntonio, Toronto, Montreal, London, Sydney, Tokyo. [17] K. Koci, Punë Laboratori të Kimisë Organike, Vëll. I dhe II, Tiranë, 2004 [18] G. Herzberg, Molecular Spectra and Molecular Structure, New York, [19] S. Gasirowicz, Quantum Physics, John Wiley & Sons, Inc., New York, [20] P.W. Atkins, Molecular Quantum Mechanics (Part I and II), Clarendon Press,Oxford, [21] Ekologija na Makedonija BALWOIS Ohrid, Republic of Macedonia - 25, 29 May