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Öğe Acute Toxicity of Organophosphorus Pesticides and Their Degradation By-products to Daphnia magna, Lepidium sativum and Vibrio fischeri(INTECH EUROPE, 2011) Aydin, Mehmet Emin; Ozcan, Senar; Beduk, Fatma[Abstract not Available]Öğe Analyses of polychlorinated biphenyls in waters and wastewaters using vortex-assisted liquid-liquid microextraction and gas chromatography-mass spectrometry(WILEY-BLACKWELL, 2011) Ozcan, SenarA method was developed for viable and rapid determination of seven polychlorinated biphenyls (PCBs) in water samples with vortex-assisted liquid-liquid microextraction (VALLME) using gas chromatography-mass spectrometry (GC-MS). At first, the most suitable extraction solvent and extraction solvent volume were determined. Later, the parameters affecting the extraction efficiency such as vortex extraction time, rotational speed of the vortex, and ionic strength of the sample were optimized by using a 2(3) factorial experimental design. The optimized extraction conditions for 5 mL water sample were as follows: extractant solvent 200 mu L of chloroform; vortex extraction time of 2 min at 3000 rpm; centrifugation 5 min at 4000 rpm, and no ionic strength. Under the optimum condition, limits of detection (LOD) ranged from 0.36 to 0.73 ng/L. Mean recoveries of PCBs from fortified water samples are 96% for three different fortification levels and RSDs of the recoveries are below 5%. The developed procedure was successfully applied to the determination of PCBs in real water and wastewater samples such as tap, well, surface, bottled waters, and municipal, treated municipal, and industrial wastewaters. The performance of the proposed method was compared with traditional liquid-liquid extraction (LLE) of real water samples and the results show that efficiency of proposed method is comparable to the LLE. However, the proposed method offers several advantages, i.e. reducing sample requirement for measurement of target compounds, less solvent consumption, and reducing the costs associated with solvent purchase and waste disposal. It is also viable, rapid, and easy to use for the analyses of PCBs in water samples by using GC-MS.Öğe ANALYTICAL METHOD OPTIMIZATION AND MONITORING OF PRIORITY ORGANIC POLLUTANTS IN URBAN AIR(NOVA SCIENCE PUBLISHERS, INC, 2009) Ozcan, Senar; Aydin, Mehmet EminIn the first phase of the research an analytical method was developed in order to determine three groups of priority organic pollutants simultaneously Such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in atmosphere quantitatively by chromatographic techniques. In the second phase of the research, PAHs, PCBs and OCPs were monitored in gas and particle phases of urban air. In determining particle phase compounds, the best extraction efficiencies were obtained by ultrasonic extraction method using 25 mL of n-hexane/petroleum ether (1/1, v/v) solvent mixture three times for 15 minutes. For determining compounds in gas phase of air samples soxhlet extraction method was carried out for 16 hours With 150 mL diethyl ether/n-hexane (1/9, v/v) solvent mixture. 10 grain 5% deactivated silica gel column was used for cleaning up the interfering substances while simultaneously fractionation of target compounds prior to GC analyses. Elutions of compounds were carried out as follow: Fraction 1: 70 mL n-hexane, Fraction 2: 3 x 20 mL n-hexane/ethyl acetate (1/1, v/v). PAHs and PCBs compounds were determined with GC/MS systems while OCPs compounds were determined using GC/mu-ECD system. Surrogate and standard spiked filters were analyzed after optimized method. Recovery were between 86%+/- 2 and 104%+/- 3 for PCBs with Relative Standard Deviation (RSD)<+/- 4, between 66%+/- 6 and 94%+/- 5 for PAHs with RSD<+/- 8, between 67%+/- 5 and 120%+/- 10 for OCPs with RSD<10. Spiked PUF plugs were also analyzed following the optimized method. Recovery ratios obtained from PUF Plugs were between 94%+/- 9 and 118%+/- 8 for PCBs with RSD%+/- 9 while the recovery ratios changed from 88%+/- l to 120%+/- 2 for PAHs with RSD<+/- 8. Recovery ratios of OCP compounds were between 65%+/- 4 and 108%+/- 6 with RSD<+/- 9. In order to determine the matrix effect on optimized method, air sampled filters and PUF plugs were spiked with standards and surrogate standards and analyzed according to the optimized method. Recovery ratios of air sampled and spiked filters and PUF plugs were not statistically significantly different from the recoveries of lion air sampled spiked filters and PUF plugs at 95% level. Gas phase and particle phase PAHs, PCBs and OCPs contents were analyzed in air samples taken from five different locations selected considering residential, industrial and traffic areas between August 2006 and May 2007. Mean PAHs concentrations were between 30 ng m(-3) and 214 ng m(-3) while mean PCBs and OCPs were between 0.04 ng m(-3) and 0.14 ng m(-3) and 0.81 ng m(-3) and 6.15 ng m(-3), respectively. Total concentration ratios found in gas phase were 61%-63% for PAHs, 63%-89% for PCBs and 45%-70% for OCPs. With increasing in temperature concentration ratios in gas phase were increased while concentration ratios in particle phase decreased for all compounds. The higher concentrations of PAHs were determined in winter seasons while the lower concentrations of PAHs were determined in summer. Results from seasonal monitoring of PCBs in urban air of Konya show that the highest PCBs concentrations were determined in September while the lowest PCBs concentrations in April. The highest total OCPs concentrations were found in autumn seasons that in these months, lands were prepared for planting by farmers. Considering the risk characterization of these compounds determined in Konya urban air it could be concluded that these compounds pose some health risks for human.Öğe Analytical Methods for Viable and Rapid Determination of Organochlorine Pesticides in Water and Soil Samples(INTECH EUROPE, 2011) Ozcan, Senar; Tor, Ali; Aydin, Mehmet Emin[Abstract not Available]Öğe Application of miniaturised ultrasonic extraction to the analysis of organochlorine pesticides in soil(ELSEVIER SCIENCE BV, 2009) Ozcan, Senar; Tor, Ali; Aydin, Mehmet EminA miniaturised ultrasonic extraction procedure was developed for the determination of different organochlorine pesticides (OCPs) in soil by gas chromatography (GC/mu-ECD). For an acetone-petroleum ether (1/1, v/v) as the extractor and a 5-min sonication, parameters such as sample amount, solvent volume and number of extraction steps were optimized by usinga 23 factorial experimental design. Limits of detection ranged from 0.02 to 1.34 mu g kg(-1). The developed procedure was applied to three different real soil samples with different fortification levels (25, 50 and 100 mu g kg(-1)) and recoveries were estimated in the 82-106% range with relative standard deviations lower than 15%. Performance of the procedure was compared with those involving traditional shaking flask, Soxhlet extraction and large-scale ultrasonic extraction. The proposed procedure requires small volumes of solvent and sample. It is viable, rapid and easy to use for analysis of OCPs in soils. (c) 2009 Elsevier B.V. All rights reserved.Öğe Application of ultrasound-assisted emulsification-micro-extraction for the analysis of organochlorine pesticides in waters(PERGAMON-ELSEVIER SCIENCE LTD, 2009) Ozcan, Senar; Tor, Ali; Aydin, Mehmet EminUltrasound-assisted emulsification-micro-extraction (USAEME) procedure was developed for the determination of different organochlorine pesticides (OCPs) in water samples by gas chromatography with mu-electron capture detection (GC-mu ECD). After the determination of the most suitable extraction solvent and its volume, parameters such as extraction time, centrifugation time and ionic strength of the sample were optimized by using a 2(3) factorial experimental design. For 10 mL of water sample, the optimized USAEME procedure used 200 mu L of chloroform as extraction solvent, 15 min of extraction without ionic strength adjustment at 25 degrees C and S min of centrifugation at 4000 rpm. Limits of detection ranged from 0.002 to 0.016 mu g L-1. Mean recoveries of OCPs from fortified water samples are over 96% for three different fortification levels between 0.5 and 5 mu g L-1 and relative standard deviations of the recoveries are below 9%. The developed procedure was successfully applied for real water samples (i.e., tap water, well water, surface (lake) water, domestic and industrial wastewater). Performance of the procedure was compared with those involving traditional liquid-liquid extraction and solid-phase extraction. The result demonstrates that the USAEME procedure is viable, rapid and easy to use for analysis of OCPs in water samples. (C) 2009 Elsevier Ltd. All rights reserved.Öğe CHEMICAL OXIDATION OF DIAZINON IN AQUEOUS SOLUTION BY OZONATION(PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2011) Beduk, Fatma; Aydin, Mehmet Emin; Ozcan, SenarIn the present study, the decomposition of diazinon by O-3, O-3/UV, and O-3/UV/H2O2 processes was studied. Diazinon and its oxidation by-product, diazoxon, were identified using gas chromatography/mass spectrometry (GC-MS). Chemical oxidation of diazinon in aqueous solution by ozonation was studied under various solution pH values and 03 concentrations. Acidic and alkaline solutions accelerated diazinon degradation, and complete mineralization of diazinon was achieved in 30 min at pH 9.0. Diazinon removal increased with ozone dosage, however, 2.0 mg L-1 of ozone with 30 min oxidation time was more economical and efficient. O-3/UV/H2O2 combination enhanced decomposition of both diazinon and diazoxon due to the reaction between analytes and hydroxyl radicals. Toxicity measurements of the treated solutions were carried out in order to evaluate the efficiency of the treatment methods. The present study validated that O-3/UV/H2O2 combination is a feasible process for the removal of the tested pesticide from aqueous solutions.Öğe Chromatographic Separation and Analytic Procedure for Priority Organic Pollutants in Urban Air(WILEY-V C H VERLAG GMBH, 2008) Ozcan, Senar; Aydin, Mehmet Emin; Tor, AliA separation procedure was developed for analysis of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in urban air, while simultaneously eliminating the interfering compounds. This was carried out by optimization of a column chromatograph with regard to the eluent type (n-hexane and n-pentane), volume of eluent, type of sorbent material (silica gel and florisil) and activation level of the sorbent material. The determination of the level of PCBs and PAHs was carried out using gas chromatography (GC) equipped with a mass selective detector (MSD), while determination of the OCPs was carried out by GC equipped with an electron capture detector (mu-ECD). The use of a silica gel column (10 g, 5% deactivated with H(2)O) with 70 mL of n-hexane gave satisfactory separation of PCBs from PAHs and OCPs. After collecting the PCBs with 70 mL of n-hexane, 3 . 20 mL of n-hexane:ethyl acetate, (1:1, v:v) was adequate for elution of the PAHs and OCPs from the column. The primary aim of this study was to develop a multimethod for analyses of PCBs, PAHs, and OCPs in urban air as well as reducing solvent and sorbent consumption and analysis time during the clean-up procedure compared to the US EPA standard methods (EPA methods TO-13A for PAHs and TO-4A for both PCBs and OCPS).Öğe Coagulation, flocculation and chemical precipitation(IWA PUBLISHING, 2012) Aydin, Mehmet Emin; Lazarova, Zdravka; Tor, Ali; Ozcan, Senar[Abstract not Available]Öğe Degradation of Malathion and Parathion by Ozonation, Photolytic Ozonation, and Heterogeneous Catalytic Ozonation Processes(WILEY-BLACKWELL, 2012) Beduk, Fatma; Aydin, Mehmet Emin; Ozcan, SenarThe oxidation of organophosphorus pesticides (OPPs), such as malathion and parathion, in aqueous solution was studied using conventional ozonation (O3), photolytic ozonation (O3/UV, O3/UV/H2O2), and heterogeneous catalytic ozonation (O3/TiO2/UV) processes. Experiments were performed in batch mode at laboratory scale and processes were compared in terms of disappearance kinetics. The best results of pesticide mineralization were obtained when TiO2 particles in combination with ozone (O3) and UV photolysis (??=?254?nm) were applied. Decomposition of 99% of parent compounds were achieved in 10?min and oxon derivatives were completely removed in 30?min. The initial reaction rate increases linearly with increasing catalyst amount. Toxicity measurements of the treated solutions were carried out in order to evaluate the efficiency of the treatment methods. No detoxification was achieved for O3 and O3/UV applications. Heterogeneous photocatalytic ozonation was shown to be feasible for achieving complete decomposition of OPPs and their oxon intermediates.Öğe Determination of Polycyclic Aromatic Hydrocarbons in Soil by Miniaturized Ultrasonic Extraction and Gas Chromatography-Mass Selective Detection(WILEY-V C H VERLAG GMBH, 2009) Ozcan, Senar; Tor, Ali; Aydin, Mehmet EminA miniaturized ultrasonic extraction procedure was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) in soil by gas chromatography-mass spectrometry. After determination of the most suitable extraction solvent with 5 min sonication time, several other parameters (sample amount, solvent volume and number of extraction times) were optimized using a 2(3) factorial experimental design. Recoveries of PAHs from spiked soil samples were over 90% for three different fortification levels between 50 and 300 mu g/kg, and relative standard deviations of the recoveries were in the range of < 1 - 15%. The limits of detection ranged from 0.002 to 1.87 mu g/kg. The performance of the developed procedure was also compared with other traditional Soxhlet, shake flask and large scale ultrasonic extraction procedures on real soil samples, and extraction methods showed comparable efficiencies. The proposed procedure required small volumes of solvent and sample. It was practicable, rapid and easy to use for analysis of PAHs in soils.Öğe Determination of selected polychlorinated biphenyls in water samples by ultrasound-assisted emulsification-microextraction and gas chromatography-mass-selective detection(ELSEVIER SCIENCE BV, 2009) Ozcan, Senar; Tor, Ali; Aydin, Mehmet EminUltrasound-assisted emulsification-microextraction (USAEME) procedure was developed for the determination of selected polychlorinated biphenyls (PCBs) in 10mL of water samples by gas chromatography-mass-selective detection. After determination of the most suitable solvent and extraction time, several other parameters including solvent volume, centrifugation time and ionic strength of the sample were optimized using a 23 factorial experimental design. The optimized USAEME procedure used 200 mu L of chloroform as extraction solvent, 10 min of extraction with no ionic strength adjustment at 25 degrees C and 5 min of centrifugation at 4000 rpm. The limits of detection ranged from 14 ng L(-1) (for PCB153) to 30 ng L(-1) (for PCB101). Recoveries of PCBs from fortified distilled water are over 80% for three different fortification levels between 0.1 and 5 mu g L(-1) and relative standard deviations of the recoveries are below 10%. The performance of the proposed method was compared with those involving traditional liquid-liquid extraction (LLE) and solid phase extraction (SPE) on the real water samples (i.e., tap and well water as well as domestic and industrial wastewaters, etc.) and comparable efficiencies were obtained. The proposed USAEME procedure has been demonstrated to be viable, simple, rapid and easy to use for residue analysis of PCBs in water samples. (C) 2009 Elsevier B.V. All rights reserved.Öğe THE EVALUATION OF GLOBAL WARMING'S EFFECTS ON SOIL TEMPERATURE OF TURKEY BY 3.5D GEOGRAPHICAL INFORMATION SYSTEM MODELS(INT SCIENTIFIC CONFERENCE SGEM, 2010) Corumluoglu, Ozsen; Aydin, Mehmet Emin; Asri, Ibrahim; Ozcan, Senar; Beduk, FatmaIn this study, global warming's effects on soil temperature of Turkey was evaluated by analysis of the spatial and temporal variations of the soil temperature data with the help of 3.5D Geographical Information System (GIS) Models. Soil temperature data in 5 cm, 10 cm, 20 cm, 50 cm and 100 cm depths in 74 city centers since 1975 were used. These data were compared with 34 years mean temperature of each city and deviations were shown by using GIS on the map. It is determined that soil temperature values in Turkey have risen about +4 degrees C in all months since 1998 except November, December and January. In deeper soil parts, temperature changes are not evident in the models. Data of 5 cm depth soil temperature in the periods of February and November 1977, April 1989, March 2001, January, March, April, July and August 2008 show an upward trend up to 5 degrees C in whole country. Semi-arid lands of Turkey are quite susceptible to temperature increases. As a result of global warming, higher temperature and lower precipitation cause higher soil temperatures in the region and this trouble results with reduction in crop quantity and quality.Öğe An investigation on the sorption behaviour of montmorillonite for selected organochlorine pesticides from water(TAYLOR & FRANCIS LTD, 2012) Ozcan, Senar; Tor, Ali; Aydin, Mehmet EminThe sorption behaviour of montmorillonite towards organochlorine pesticides (OCPs) from aqueous solutions is reported. After preliminary investigation of the sorption capability of clay for selected OCPs, aldrin was used as a model compound for further experiments. The batch sorption experiments were carried out as functions of contact time, pH of the solution, initial aldrin concentration and dosage of the montmorillonite. After traditional liquid-liquid extraction, the determination of OCPs was carried out by gas chromatography coupled with a mu-electron capture detector (GC-mu ECD). The results indicated that sorption of aldrin followed the second-order kinetic model and that the equilibrium time depended on the initial aldrin concentration. The film diffusion was found to be a main sorption rate control mechanism. The removal was explained according to the electrostatic bonding mechanism. The Freundlich isotherm model better represented the sorption data than the Langmuir model. The montmorillonite was also used efficiently for the removal of OCPs from fortified tap and surface (lake) water samples.Öğe Levels of Organohalogenated Pollutants in Human Milk Samples from Konya City, Turkey(WILEY, 2011) Ozcan, Senar; Tor, Ali; Aydin, Mehmet EminThis study reports the levels of organochlorine pesticides (OCPs, alpha-, beta-, gamma- and Delta-HCHs, p,p'-DDE, p,p'-DDD and p,p'-DDT), polychlorinated biphenyls (PCBs, PCB 28, 52, 101, 153, 138 and 180 congeners) and polybrominated diphenyl ethers (PBDEs, PBDE 47, 99, 100, 153 and 154 congeners) in 45 individual human milk samples collected from Konya City, Turkey. Average concentrations of Sigma HCHs, Sigma DDTs, Sigma PCBs and Sigma PBDEs were 22.62, 37.10, 104.95 and 67.34 ng/g lipid wt., respectively. No significant differences in investigated pollutants were found between primiparous and multiparous mothers. There was no correlation between levels of each group of pollutants in human milk and the age of mothers. Moreover, there was no significant difference in the levels of Sigma DDTs, between mothers who have eaten fish more than once a week and those who consumed fish less than once. An analysis of the infant exposure to DDTs, HCHs and PCBs via mother's milk indicated that the estimated daily intakes of these pollutants were below the guideline proposed by the World Health Organization (WHO) and the Health Canada which means that there is definitely no concern on children health.Öğe Organochlorine Pesticides in Urban Air: Concentrations, Sources, Seasonal Trends and Correlation with Meteorological Parameters(WILEY, 2009) Ozcan, Senar; Aydin, Mehmet EminThe concentrations of organochlorine pesticides (OCPs) in both the gas and particulate phases of urban air samples were determined. The samples were collected between August 2006 and May 2007 at four different locations in Konya, Turkey,. OCPs were analyzed by gas chromatography with micro electron capture detection (GC/mu-ECD). The average total (gas + particulate) concentrations of OCPs were determined to be between 809 and 6309 pg/m(3). The highest OCP levels were found in autumn. Total hexachlorocyclohexane (HCH, sum of alpha, beta, gamma, delta-HCH), total DDT's (sum of p,p(i)-DDT, p,p(i)-DDD and p,p(i)-DDE) and endosulfan compounds (sum of endosulfan I, endosulfan II and endosulfan Sulfate) were about 43, 25 and 17% of total OCPs, respectively. OCPs were predominantly detected in the particulate phase. Correlations were observed between OCP concentration and temperature, relative humidity. wind speed and Total Suspended Particulate. PM10, but the variation between meteorological parameters with OCP concentrations could not be explained completely. Despite banned/restricted use in Turkey, all the OCP were found in urban air. p,p(i)-DDT/p,p(i)-DDE ratios were above 11 which is all indication of current use of DDT compounds. Therefore, it could he suggested that Konya is an actively contributing region to organochlorine pesticides pollutants in Turkey.Öğe Polycyclic aromatic hydrocarbons, polychlorinated biphenyls and organochlorine pesticides in urban air of Konya, Turkey(ELSEVIER SCIENCE INC, 2009) Ozcan, Senar; Aydin, Mehmet EminPolycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in urban air samples of Konya, Turkey between August 2006 and May 2007. The concentrations of pollutants in both the gas and particulate phase were separately analysed. The average total (gas + particulate) concentrations of PAHs, PCBs and OCPs were determined as 206 ng m(-3), 0.106 ng m(-3), 4.78 ng m(-3) respectively. All of the investigated target compounds were dominantly found in the gas phase except OCPs. Higher air concentrations of PAHs were found at winter season while the highest concentrations of PCBs were determined in September. The highest OCPs were detected in October and in March. In urban air of Konya, PCB 28 and PCB 52 congeners represent 46% and 35% of total PCBs while Phenanthrene, Fluoranthene, Pyrene accounted for 29%, 13%, 10% of total PAHs. HCH compounds (alpha + beta + gamma + delta-HCH), total DDTs (p,p'-DDE, p,p'-DDD, p,p'-DDT), Endosulfan compounds (Endosulfan I, Endosulfan II, Endosulfan sulfate) were dominantly determined as 30%, 21%, 20% of total OCPs respectively. Considering the relation between these compounds with temperature, there was no significant correlation observed. Despite banned/restricted use in Turkey, some OCPs were determined in urban air. These results demonstrated that they are either illegally being used in the course of agricultural activity and gardens in Konya or they are residues of past use in environment. According to these results, it can be suggested that Konya is an actively contributing region to persistent organic pollutants in Turkey. (C) 2009 Elsevier B.V. All rights reserved.Öğe REMOVAL OF LINDANE AND DIELDRIN FROM AQUEOUS SOLUTIONS BY MONTMORILLONITE AND BENTONITE AND OPTIMIZATION OF PARAMETERS(PARLAR SCIENTIFIC PUBLICATIONS (P S P), 2009) Aydin, Mehmet E.; Ozcan, Senar; Beduk, FatmaDifferent pesticides are widely applied in agricultural activities. To remove these toxic compounds from the aquatic environment and to reduce the dispersion of pollutants, different clays can effectively be used as alternative adsorbents to commonly used activated carbon. In this study montmorillonite and bentonite clays were used to adsorb lindane (gamma-HCH) and dieldrin, by a batch equilibration technique. The study was carried out as functions of contact time, pH, initial lindane and dieldrin concentrations, amount of montmorillonite and bentonite and adsorption isotherms were obtained as Freundlich Isotherm. Clays were activated by calcination and acid treatment. Adsorption was improved after acid treatment of used clays, however calcinations of the clays up to 500 degrees C did not reveal any discernible effect on the adsorption.Öğe Removal of Organochlorine Pesticides from Aqueous Solution by Using Neutralized Red Mud(WILEY, 2011) Ozcan, Senar; Tor, Ali; Aydin, Mehmet EminThis work describes the potential usability of neutralized red mud for the removal of organochlorine pesticides (OCPs) from aqueous solutions. After examination on the adsorption capability of neutralized red mud for all studied OCPs, the experiments were performed by employing aldrin as a model compound. The effect of several parameters, such as contact time, pH of the solution, initial aldrin concentration, and dosage of the adsorbent was evaluated by batch experiments. The determination of OCPs was carried out using traditional liquid-liquid extraction followed by a GC coupled with mu-electron capture detector (GC-mECD). The results showed that adsorption equilibrium time depended upon the initial aldrin concentration and adsorption followed the second-order kinetic model. Kinetic study also indicated that the film diffusion mechanism was a main rate control mechanism. The removal was explained by considering the electrostatic interactions between metal oxides surface of the neutralized red mud and inductively charged centers (negative charge (d-) of chlorine atoms and positive charge (d+) of pi-cloud aromatic ring) of the aldrin molecules. In comparison to the Langmuir isotherm model, the Freundlich model better represented the adsorption data. The neutralized red mud was also succesfully employed for the removal of OCPs from real water samples, including tap water and surface (lake) water, fortified with studied OCPs.Öğe Sedimentation and flotation(IWA PUBLISHING, 2012) Tor, Ali; Ozcan, Senar; Aydin, Mehmet Emin[Abstract not Available]
