Seasonal variations of heavy metals in some organs of carp (Cyprinus carpio L., 1758) from Beyşehir Lake (Turkey)

In this study which was carried out between March 2003 and February 2005 Fe, Cu, Zn, Mn, Cr, Pb and Cd contents were determined in muscle, liver and gill of carp (Cyprinus carpio L., 1758) caught from Beyşehir Lake. Among the heavy metals analyzed Cr, Pb and Cd were below the detection limit (<0.03). Heavy metal concentrations varied significantly depending on the type of the tissue and season. The highest metal concentrations were found in the liver, followed by gill and muscle. Heavy metal levels in tissues of carp were increased in summer and winter, while were decreased in autumn and spring. The present study shows that precautions need to be taken in Beyşehir Lake in order to prevent heavy metal pollution that can occur in the future.     

Potential use of thermophilic dark fermentation effluents in photofermentative hydrogen production by Rhodobacter capsulatus

Biological hydrogen production by a sequential operation of dark and photofermentation is a promising route to produce hydrogen. The possibility of using renewable resources, like biomass and agro-industrial wastes, provides a dual effect of sustainability in biohydrogen production and simultaneous waste removal. In this study, photofermentative hydrogen production on effluents of thermophilic dark fermentations on glucose, potato steam peels (PSP) hydrolysate and molasses was investigated in indoor, batch operated bioreactors. An extreme thermophile Caldicellulosiruptor saccharolyticus was used in the dark fermentation step, and Rhodobacter capsulatus (DSM1710) was used in the photofermentation step. Addition of buffer, Fe and Mo to dark fermentor effluents (DFEs) improved the overall efficiency of hydrogen production. The initial acetate concentration in the DFE needed to be adjusted to 30–40 mM by dilution to increase the yield of hydrogen in batch light-supported fermentations. The thermophilic DFEs are suitable for photofermentative hydrogen production, provided that they are supplemented with buffer and nutrients. The overall hydrogen yield of the two-step fermentations was higher than the yield of single step dark fermentations.     

Evaluation of land-use regression models used to predict air quality concentrations in an urban area

Cohort studies designed to estimate human health effects of exposures to urban pollutants require accurate determination of ambient concentrations in order to minimize exposure misclassification errors. However, it is often difficult to collect concentration information at each study subject location. In the absence of complete subject-specific measurements, land-use regression (LUR) models have frequently been used for estimating individual levels of exposures to ambient air pollution. The LUR models, however, have several limitations mainly dealing with extensive monitoring data needs and challenges involved in their broader applicability to other locations. In contrast, air quality models can provide high-resolution source–concentration linkages for multiple pollutants, but require detailed emissions and meteorological information. In this study, first we predicted air quality concentrations of PM_2.5, NO_x, and benzene in New Haven, CT using hybrid modeling techniques based on CMAQ and AERMOD model results. Next, we used these values as pseudo-observations to develop and evaluate the different LUR models built using alternative numbers of (training) sites (ranging from 25 to 285 locations out of the total 318 receptors). We then evaluated the fitted LUR models using various approaches, including: 1) internal “Leave-One-Out-Cross-Validation” (LOOCV) procedure within the “training” sites selected; and 2) “Hold-Out” evaluation procedure, where we set aside 33–293 tests sites as independent datasets for external model evaluation. LUR models appeared to perform well in the training datasets. However, when these LUR models were tested against independent hold out (test) datasets, their performance diminished considerably. Our results confirm the challenges facing the LUR community in attempting to fit empirical response surfaces to spatially- and temporally-varying pollution levels using LUR techniques that are site dependent. These results also illustrate the potential benefits of enhancing basic LUR models by utilizing air quality modeling tools or concepts in order to improve their reliability or transferability.     

Quality and Quantity of Leachate in Aerobic Pilot-Scale Landfills

In this study, two pilot-scale aerobic landfill reactors with (A1) and without (A2) leachate recirculation are used to obtain detailed information on the quantity and quality of leachate in aerobic landfills. The observed parameters of leachate quality are pH, chloride (Cl⁻), chemical oxygen demand (COD), biological oxygen demand (BOD), total Kjeldahl nitrogen (TKN), ammonia nitrogen (NH₃-N), and nitrate (NO₃^–-N). pH values of the leachate increased to 7 after 50 days in reactor A1 and after 70 days in reactor A2. Cl⁻ concentrations increased rapidly to 6100 (A1) and 6900 (A2) mg/L after 80 days, from initial values of 3000 and 2800 mg/L, respectively. COD and BOD values decreased rapidly in the A1 landfill reactor, indicating the rapid oxidation of organic matter. The BOD/COD ratio indicates that leachate recirculation slightly increases the degradation of solid waste in aerobic landfills. NH₃-N concentrations decreased as a result of the nitrification process. Denitrification occurred in parts of the reactors as a result of intermittent aeration; this process causes a decrease in NO₃⁻ concentrations. There is a marked difference between the A1 and A2 reactors in terms of leachate quantity. Recirculated leachate made up 53.3% of the leachate generated from the A1 reactor during the experiment, while leachate quantity decreased by 47.3% with recirculation when compared with the aerobic dry landfill reactor.     

Characterization of an urban landfill soil by using physicochemical analysis and solid phase microextraction (SPME)—GC/MS

We have aimed at characterizing top soil samples taken in-situ from five different locations of the unregulated dumping site in Eskişehir/Turkey for a period of six months. The study is the first attempt in the city and in Turkey, regarding particularly the SPME (Solid Phase Microextraction Technique) analysis method utilized. A comprehensive research has been conducted to produce critical soil data to be used for indicating current risks as well as the urgency of rehabilitating the site and establishing a sanitary landfill in the site. Conventional physicochemical analytical methods and SPME technique were used to analyze the samples. Physicochemical analyses were performed for determining the pH, total dried matter, volatile matter, total nitrogen, phosphorus, macro elements and heavy metals. Meteorological data were also recorded for the same period. SPSS.10.0 statistical program was used to determine the correlation between meteorological data and physicochemical analysis results. Mean values were used in the correlation analyses. These data indicated that the air temperature and precipitation have significant effects on soil characteristics. SPME, coupled with GC/MS, was used to identify eighty six volatile and semi-volatile organic compounds contained in soil samples. The samples were extracted by headspace SPME with heating (δHS-SPME). SPME analyses were conducted using a commercially available polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber having a film thickness of 65 μm (Supelco) as a capture medium. The experimentally optimized headspace sampling conditions were arranged (15 min. at 50^˚C) before a 30 min. sampling period.     

Delineation of soil and groundwater contamination using geophysical methods at a waste disposal site in Çanakkale, Turkey

Direct current (DC) resistivity, self potential (SP) and very low frequency electromagnetic (VLF-EM) measurements are carried out to detect the spread of groundwater contamination and to locate possible pathways of leachate plumes, that resulted from an open waste disposal site of Canakkale municipality. There is no proper management of the waste disposal site in which industrial and domestic wastes were improperly dumped. Furthermore, because of the dumpsite is being located at the catchment area borders of a small creek and is being topographically at a high elevation relative to the urban area, the groundwater is expected to be hazardously contaminated. Interpretations of DC resistivity geoelectrical data showed a low resistivity zone (<5 ohm-m), which appears to be a zone, that is fully saturated with leachate from an open dumpsite. The VLF-EM and SP method, support the results of geoelectrical method relating a contaminated zone in the survey area. There is a good correlation between the geophysical investigations and the results of previously collected geochemical and hydrochemical measurements.     

Evaluation of air quality by passive and active sampling in an urban city in Turkey: current status and spatial analysis of air pollution exposure

Concentrations of air pollutants, nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), ozone (O(3)), particulate matter (PM(2.5) and PM(10)), trace metals, and polycyclic aromatic hydrocarbons (PAHs) were measured in 2008 and 2009 in the city of Eski?ehir, central Turkey. Spatial distributions of NO(2), SO(2), and ozone were determined by passive sampling campaigns carried out during two different seasons with fairly large spatial coverage. A basic population exposure assessment was carried out employing Geographical Information System techniques by combining population density maps with pollutant distribution maps of NO(2) and SO(2). It was found that 95 % of the population is exposed to NO(2) levels close to the World Health Organization guideline value. Regarding SO(2), a large proportion of the population (83 %) is exposed to levels above the WHO second interim target value. Concentrations of all the pollutants showed a seasonal pattern increasing in winter period, except for ozone having higher concentrations in summer season. Daily PM(10) and PM(2.5) concentrations exceeded European Union limit values almost every sampling day. Toxic fractions of the measured PAHs were calculated and approximately fourfold increase was observed in winter period. Copper, Pb, Sn, As, Cd, Zn, Sb, and Se were found to be moderately to highly enriched in PM(10) fraction, indicating anthropogenic input to those elements measured. Exposure assessment results indicate the need for action to reduce pollutant emissions especially in the city center. Passive sampling turns out to be a practical and economical tool for air quality assessment with large spatial coverage.     

The fatty acid compositions of several plant seed oils belong to Leguminosae and Umbelliferae families

In samples with 1,009, 7,723, 7,618, 7,618, 1,004 and 1,009 number, oleic acid were found as 62.0, 77.0, 74.84, 71.55, 54.52 and 62.30 %, respectively. In other samples, oleic acid content was determined between 17.43 % (1,589) and 34.86 % (1,298). Linoleic acid content of seed oils ranged from 6.52 % (7,727) to 57.29 % (1,501). In addition, linolenic acid content was found between 0.22 % (7,618) and 46.91 % (1,589). Palmitic acid content of samples changed between 2.03 % (7,727) and 19.81 % (1,298). Capric acid was found at high level in 1,009 (8.53 %), 7,727 (37.31 %) and 1,004 (8.28 %) samples. Caproic acid was found in only 7,727 (3.38 %).     

Indoor airborne fungal pollution in newborn units in Turkey

Pathogenic and/or opportunistic fungal species are major causes of nosocomial infections, especially in controlled environments where immunocompromised patients are hospitalized. Indoor fungal contamination in hospital air is associated with a wide range of adverse health effects. Regular determination of fungal spore counts in controlled hospital environments may help reduce the risk of fungal infections. Because infants have inchoate immune systems, they are given immunocompromised patient status. The aim of the present study was to evaluate culturable airborne fungi in the air of hospital newborn units in the Thrace, Marmara, Aegean, and Central Anatolia regions of Turkey. A total of 108 air samples were collected seasonally from newborn units in July 2012, October 2012, January 2013, and April 2013 by using an air sampler and dichloran 18% glycerol agar (DG18) as isolation media. We obtained 2593 fungal colonies comprising 370 fungal isolates representing 109 species of 28 genera, which were identified through multi-loci gene sequencing. Penicillium, Aspergillus, Cladosporium, Talaromyces, and Alternaria were the most abundant genera identified (35.14, 25.40, 17.57, 2.70, and 6.22% of the total, respectively).