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Odors due to malodorous gas and vapor emissions from units of Izmir Wastewater Treatment Plant (WWTP) were studied and evaluated with respect to chemical composition. Altogether 29 target compounds consisting of 4 different groups of chemicals were identified and quantified in the odorous gas samples from wastewater and sludges. Total volatile malodorous organic compounds (VMOC) consisted of reduced sulfur compounds (RSCs) and different volatile organic compounds (VOCs) including volatile organic compounds (VOCs), aldehydes, monoaromatics (BTX) and some halogenated organics. Among these components the most abundant group was the monoaromatics (69% of the total VOC). A statistically significant linear relationship was found between odor concentrations determined by olfactometry and total VOC concentrations (r2 = 0.89, n = 5, P < 0.05) in the samples of odorous gases. Based on the odor contribution ratios of the compounds studied, the results of the study revealed that hydrogen sulfide, propanal and toluene were dominating in the odor emissions and these were explaining 99% of the variability in odor concentrations (r2 = 0.99, n = 5, P < 0.05). It was shown that not only the hydrogen sulfide and RSCs but also other organics were important in forming the odors from sludge units and sludge management areas. [ABSTRACT FROM AUTHOR]

Odor levels around a meat packaging and rendering plant were predicted by using the CALPUFF dispersion model. The product of olfactometrically measured odor concentration and volumetric flow rate of the stack gas stream was used as emission strength of the source. Ambient odor levels were also measured at two sites downwind of the plant by olfactometry. This was possible, as odor concentrations were above 50 odor units per cubic meter (OU m −3 ), and this means that the concentrations were always exceeding the minimum 10 OU m−3 that can be safely measured by this technique. Odor samples were taken consecutively at two sites downwind of the source with 10 s duration each. These sampling sites were chosen so that they had continuous odor nuisance problems, which indicated that they were near the centerline of the plume. Between samples 10-s intervals were necessary to prepare the sampler for the next sampling bag connection. The overall sampling period was 10 min each at the two sites. Meteorological measurements were carried out throughout the odor sampling process at the sites. Wind direction and speeds were recorded at the end of each sampling and used in predictions made using the model. Predicted results were compared with the odor measurements carried out on the samples. Measured and predicted odor concentrations were tested to see the degree of correlation. The measured and predicted results at such very short averaging times correlated well, with a good agreement between the two series. [ABSTRACT FROM AUTHOR]

The estimated exhaust emissions from railway vehicles in Turkey were presented. The emissions of nitrogen oxides (NO X ), hydrocarbon compounds (HC), carbon monoxide (CO), particulate matter (PM), sulfur dioxide (SO2) and carbon dioxide (CO2) from the diesel locomotives and railcars were calculated using the railway traffic data recorded by Turkish State Railways (TSR) for the period of 2000–2005. EPA emission factors were used for different vehicle types and operation modes such as shunting and line-hauling. Total emissions from railway vehicles in Turkey were estimated as 384 t y−1 for HC, 1016 t y−1 for CO, 6799 t y−1 for NO X , 256 t y−1 for PM, 357 t y−1 for SO2 and 383 537 t y−1 for CO2 for the year 2005. The distribution of emissions with respect to type of railway vehicles shows that the mainline locomotives contribute ∼91% to the total emissions. The increases of 22%, 39% and 49% in the current numbers of mainline locomotives, shunting locomotives and diesel railcars, respectively corresponding to the full capacity of railway network in Turkey will increase the annual emissions to 431 t y−1 for HC, 1121 t y−1 for CO, 7399 t y−1 for NO X , 342 t y−1 for PM, 552 t y−1 for SO2 and 420 256 t y−1 for CO2. Total railway emissions constitute 0. 15%, 0. 08% and 4. 21% of total Turkish traffic emissions for HC, CO and NO X , respectively. [Copyright &y& Elsevier]

Abstract: The composition of odorous gases emitted from a municipal landfill in the city of Izmir, Turkey was investigated using gas chromatography–mass spectrometry, and these data were examined in relation with the odor concentrations. Several volatile organic compounds (VOCs) were identified and quantified at five sampling sites in May and September 2005. Detected VOCs were monoaromatics (0.09–47.42μgm−3), halogenated compounds (0.001–62.91μgm−3), aldehydes (0.01–38.55μgm−3), esters (0.01–7.54μgm−3), ketones (0.03–67.60μgm−3), sulfur/nitrogen containing compounds (0.03–5.05μgm−3), and volatile fatty acids (VFAs) (0.05–43.71μgm−3). High levels of aldehydes (propanal up to 38.55μgm−3) and VFAs (formic acid up to 43.71μgm−3) were measured in May. However, VOC concentrations were relatively low in September. The monoaromatics and halogenated compounds were the abundant VOCs in landfill air for the both sampling periods. The benzene-to-toluene (B:T) ratio at the landfill site was significantly lower than urban areas indicating the presence of higher amounts of toluene in landfills compared to traffic exhaust rich urban areas. A statistically significant linear relationship was found between odor concentrations determined by olfactometry and total VOC concentrations. The relationships of odor concentrations with the different groups of chemicals were also examined using a step-wise multiple regression analysis. It was found that the concentrations of aldehydes, ketones, and esters are the best estimators, explaining 96% of the variability in odor concentrations (r 2 =0.96, n =10, P < 0.01). [Copyright &y& Elsevier]

Abstract: The relationship between odor concentrations (olfactometry) and chemical concentrations (gas chromatography-mass spectrometry, GC-MS) was studied for the odorous air compositions of a rendering plant, a sanitary landfill and an industrial area with large petroleum and petrochemical industries. Samples taken from the university campus located in a non-industrial and non-urban area were also studied for several organic components for comparison. Ambient air samples were taken into special bags by using an odor sampling device designed for field sampling of odors. In the laboratory odorous chemicals in the samples were transferred into adsorbent tubes and analyzed using a combination of thermal desorption and GC-MS. Results point to different characteristics of the odorous gases and air in and around the urban and industrial sources. Among the 64 specific compounds studied, 49 volatile organic compounds (VOCs) were detected in rendering plant, 53 VOCs were detected in sanitary landfill and 44 VOCs were detected in petroleum and petrochemical industries. The compounds measured in the odorous gas composition are the alkanes, alkenes, carbonyls, arenes, chlorinated and other halogenated compounds and organic chlorides as well as the volatile fatty acids. [Copyright &y& Elsevier]