Odor-causing volatile organic compounds in wastewater treatment plant units and sludge management areas

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 (r(2) = 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 (r(2) = 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

Chemical characterization of odors due to some industrial and urban facilities in Izmir, Turkey

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 GGMS. Results point to different characteristics of the odorous gases and air in and around the urban and industrial sources

Behaviour of trace metals in surface sediments of the black sea

Early diagenetic processes control the behavior, and more specifically the dissolved-solid phase distribution of heavy metals in sediments. The depth distribution of Co, Mn, Cu, Zn, Ni, and Fe in sediment were determined in box cores from the Black Sea. The sequential analyses results of these metals indicate contrasting behavior of Mn and Co during early diagenesis, consistent with their respective chemistries and particle-associations. The profiles of extractable trace metals in the cores are clearly related to sediment type or depositional environment. Topmost sections of the profiles for these elements are generally similar, i.e. rapid decrease in concentration below the sediment surface. © 1995, Taylor & Francis Group, LLC. All rights reserved

Odor determination at wastewater collection systems: Olfactometry versus H2S analyses

H2S is usually the main indicator parameter to assess when nuisance odors arise in wastewater handling systems. However, sampling and measurement of H2S need to be made with utmost care and analytical methods are neither easy nor cheap. Although Jerome meters from Arizona Instruments are used in some parts of the world, the cost and difficulty of measuring H2S in odorous gases is a general problem. It should also be kept in mind that a simple linear relationship between H2S concentrations and odor perception by the public is not available, especially in complex odorous gas mixtures. This leads to the conclusion that measuring the H2S alone is neither easy nor accurate in describing and resolving public complaints due to odors from wastewater collection and treatment systems. In this study, data for odors and H2S measurements from two pumping stations of the wastewater collection system of Cesme, Izmir, Turkey are evaluated. Concentrations of H2S were measured with chemical methods. Results indicated concentrations several orders of magnitude above the odor threshold level, which is generally accepted as 0.1 mu g/m(3) for pure H2S in air. The statistical relationships between analytical and sensory odor data were established. Correlations indicated power law relationships between odor and H2S concentrations (R-2 between 0.88-0.92). Steven's law between the intensity of human perception and concentration of stimulants is obeyed

Solubility of deposited airborne heavy metals

Toxic effects of heavy metals in water and soil environments are important. Quantifying the heavy metal concentrations and their solubilities in dry and wet deposition samples is part of atmospheric research. Soluble fractions of the deposited air pollutants are important in food chain mechanisms as heavy metals may cause ecotoxic impacts. In this study, the solubilities of Cr, Cd, Pb, Cu, Zn, and Ni were investigated in deposition samples for total, dissolved, and suspended fractions after collection in a surrogate, water-surface sampler in Izmir, Turkey, during October 2003 to June 2004. To find overall solubility of each metal in dry and wet deposition samples, concentrations in soluble and suspended phases of aqueous solutions were analyzed separately. Ratios between total and dissolved forms and the metals in the same forms were analyzed and evaluated statistically

Deposition of heavy metals in a Mediterranean climate area

Deposition samples were collected and analyzed for selected heavy metals in Izmir, Turkey on different days in October 2003-June 2004. A water surface sampler was used to collect dry deposition and rainwater samples to represent the wet deposition during the rainy period of the year. Heavy metal concentrations and fluxes of both dry and wet deposition forms were determined

Processes affecting the movement of organochlorine pesticides (OCPs) between soil and air in an industrial site in Turkey

Soil and atmospheric concentrations, dry deposition and soil-air gas exchange of organochlorine pesticides (OCPs) were investigated at an industrial site in Aliaga, Izmir, Turkey. Current-use pesticides, endo-sulfan and chlorpyrifos, had the highest atmospheric levels in summer and winter. Summertime total (gas + particle) OCP concentrations in air were higher, probably due to increased volatilization at higher temperatures and seasonal local/regional applications of current-use pesticides. Particle deposition fluxes were generally higher in summer than in winter. Overall average dry particle deposition velocity for all the OCPs was 4.9 +/- 4.1 cm, s(-1) (average +/- SD). Sigma DDXs (sum of p,p'-DDT, p,p'-DDD, and p,p'-DDE) were the most abundant OCPs in Aliaga soils (n = 48), probably due to their heavy historical use and persistence. Calculated fugacity ratios and average net gas fluxes across the soil-air interface indicated volatilization for alpha-CHL. gamma-CHL. heptachlorepoxide, cis-nonachlor, trans-nonachlor, and p,p'-DDT in summer, and for alpha-CHL, gamma-CHL trans-nonachlor, endosulfan sulfate, and p,p'-DDT in winter. For the remaining OCPs, soil acted as a sink during both seasons. Comparison of the determined fluxes showed that dry particle, gas-phase, and wet deposition are significant OCP input mechanisms to the soil in the study area. (C) 2009 Elsevier Ltd. All rights reserved

Dry deposition and soil-air gas exchange of polychlorinated biphenyls (PCBs) in an industrial area

Ambient air and dry deposition, and soil samples were collected at the Aliaga industrial site in Izmir, Turkey. Atmospheric total (particle + gas) Sigma(41)-PCB concentrations were higher in summer (3370 1617 pg m(-3). average + SD) than in winter (1164 +/- 618 pg m(-3)), probably due to increased volatilization with temperature. Average particulate Sigma(41)-PCBs dry deposition fluxes were 349 +/- 183 and 469 +/- 328 ng m(-2) day(-1) in summer and winter, respectively. Overall average particulate deposition velocity was 5.5 +/- 3.5 cm s(-1). The spatial distribution of Sigma(41)-PCB soil concentrations (n = 48) showed that the iron-steel plants, ship dismantling facilities, refinery and petrochemicals complex are the major sources in the area. Calculated air-soil exchange fluxes indicated that the contaminated soil is a secondary source to the atmosphere for lighter PCBs and as a sink for heavier ones. Comparable magnitude of gas exchange and dry particle deposition fluxes indicated that both mechanisms are equally important for PCB movement between air and soil in Aliaga. (C) 2008 Elsevier Ltd. All rights reserved

Chemical characterization of odorous gases at a landfill site by gas chromatography-mass spectrometry

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 (0.09-47.42 mu g m(-3)), halogenated compounds (0.001-62.91 mu g m(-3)), aldehydes (0.0 1-38.55 mu g m(-3)), esters (0.01-7.54 mu g m(-3)), ketones (0.03-67.60 mu g m(-3)), sulfur/nitrogen containing compounds (0.03-5.05 mu g m(-1)), and volatile fatty acids (VFAs) (0.05-43.71 mu g m(-3)). High levels of aldehydes (propanal up to 38.55 mu g m(-3)) and VFAs (formic acid up to 43.71 mu g m(-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). (c) 2006 Elsevier B.V. All rights reserved

Atmospheric concentrations, dry deposition and air-soil exchange of polycyclic aromatic hydrocarbons (PAHs) in an industrial region in Turkey

Concurrent ambient air and dry deposition samples were collected during two sampling periods at the Aliaga industrial region in Izmir, Turkey. Sigma(15)-PAH (particulate + gas) concentrations ranged between 7.3 and 44.8 ng m-3 (average +/- S.D., 25.2 +/- 8.8 ng m(-3)) and 10.2-71.9 ng m(-3) (44.1 +/- 16.6 ng m(-3)) in summer and winter, respectively. Winter/summer individual ambient PAH concentration ratios ranged between 0.8 (acenaphthene) and 6.6 (benz[a]anthracene) indicating that wintertime concentrations were affected by residential heating emissions. In contrast to the ambient concentrations, Sigma(15)-PAH particle dry deposition fluxes were higher in summer (5792 +/- 3516 ng m(-2) day(-1), average +/- S.D.) than in winter (2650 +/- 1829 ng m(-2) day(-1)), probably due to large particles from enhanced re-suspension of polluted soil particles and road dust. Average overall dry deposition velocity of PAHs calculated using the dry deposition fluxes and particle-phase concentrations was 2.9 +/- 3.5 cm s(-1). Sigma(15)-PAH concentrations in soils taken from 50 points in the area ranged between 11 and 4628 mu g kg(-1) in dry weight. The spatial distribution of these concentrations indicated that the urban Aliaga, steel plants, the petroleum refinery, and the petrochemical plant are the major Sigma(15)-PAH sources in the area. Fugacity calculations in air and soil showed that the soil acts as a secondary source to the atmosphere for low molecular weight PAHs in summer and as a sink for the higher molecular weight ones in summer and winter. (C) 2007 Elsevier B.V. All rights reserved